Patent Publication Number: US-2023133914-A1

Title: Power switching device and application thereof

Description:
TECHNICAL FIELD 
     The disclosure relates to the field of garden tools technology, and more particularly to a power switching device and applications thereof. 
     BACKGROUND 
     In the garden machinery and power tool industries, power tools usually have a rated working voltage, that is, tools of different rated voltages need battery packs with different rated voltages to provide power. In order to solve the above problems, there is a battery pack which can realize two voltages switching in the existing market. 
     In the prior art, the voltage regulation structure of the dual-voltage battery pack is integrated on the battery pack, and the voltage selection is realized through different external plugs (male plugs), so that the battery pack can output different voltages. In the field of large-volume battery or backpack battery, the tool and the battery are not directly plugged in, but connected through a power cord, so that it is inconvenient to realize different voltage outputs through different male plugs. 
     SUMMARY 
     A power switching device provided in the disclosure includes a plug, connected to a power supply device and including an output terminal; and a power switching assembly, connected to the plug and including a switching member, wherein the switching member is configured for switching a coupling form of the plug. 
     An electric energy storage system provided in the disclosure includes a first energy unit; and a second energy unit, connected to the first energy unit through a power switching device, wherein the power switching device is configured for changing series-parallel connections between the first energy unit and the second energy unit by a switching of switching positions; wherein the power switching device includes: a plug, connected to a power supply device and including an output terminal; and a power switching assembly, connected to the plug and including a switching member, wherein the switching member is configured for switching a coupling form of the plug. 
     An electric power tool provided in the disclosure includes an electric energy storage system; and a power switching device, operatively cooperated with the electric energy storage system to make an output voltage from the electric energy storage system be matched with a rated voltage of an electric tool; wherein the power switching device includes: a plug, connected to a power supply device and including an output terminal; and a power switching assembly, connected to the plug and including a switching member, wherein the switching member is configured for switching an electrical coupling form of the plug. 
     An electric tool system provided in the disclosure includes an electric tool; and an electric energy storage system, including a power switching device, wherein the electric energy storage system matches the electric tool through the power switching device; wherein the power switching device includes: a plug, connected to a power supply device and including an output terminal; and a power switching assembly, connected to the plug and including a switching member, wherein the switching member configured for switching a coupling form of the plug. 
     In summary, the power switching device in the disclosure can realize the output of different voltages by the switching member moving between a first position and a second position, the plug connected with the switching member, and the switching of the coupling form of different plugs. Meanwhile, the power switching device can also enable an electric power tool with the power switching device to match many power supply devices with different output voltages, which effectively increases the applicable range of the electric energy storage system/power tool/electric tool system with the power switching device, and reduces cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  2    is a schematic structural view of the electric energy storage system in  FIG.  1    without a power switching device and part of a casing. 
         FIG.  3    is a perspective schematic view of the power switching device in  FIG.  1   . 
         FIG.  4    is a schematic exploded view of the power switching device in  FIG.  1   . 
         FIG.  5    is a schematic exploded view of the switching member in  FIG.  4   . 
         FIG.  6    is a schematic assembled structural view of the power switching assembly and the plug when the power switching device is in a first position. 
         FIG.  7    is a schematic assembled structural view of the power switching assembly of  FIG.  6    when the elastic member is omitted. 
         FIG.  8    is a schematic connection structural view of the plug when the power switching device is in a first position. 
         FIG.  9    is a schematic circuit diagram of the electric energy storage system when the power switching device is in a first position. 
         FIG.  10    is a schematic assembled structural view of the power switching assembly and the plug when the power switching device is in a second position and the elastic member is omitted. 
         FIG.  11    is a schematic connection structural view of the plug when the power switching device is in a second position. 
         FIG.  12    is a schematic structural circuit diagram of the electric energy storage system when the power switching device is in a second position. 
         FIG.  13    is a partial enlargement view of a connecting position of the switching portion and the switching member in  FIG.  4   . 
         FIG.  14    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  15    is a schematic structural view of the power switching device in  FIG.  14    from another angle. 
         FIG.  16    is a schematic exploded view of the power switching device in  FIG.  14   . 
         FIG.  17    is a schematic structural view of the power switching assembly in  FIG.  14   . 
         FIG.  18    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  14   . 
         FIG.  19    is a schematic exploded structural view of a second switching member in  FIG.  14   . 
         FIG.  20    is a schematic assembled structural view of the second switching member and the plug in  FIG.  14   . 
         FIG.  21    is a schematic structural circuit diagram of the electric energy storage system in  FIG.  14   . 
         FIG.  22    is a schematic structural circuit diagram of the electric energy storage system when the power switching device is in a first position. 
         FIG.  23    is a schematic structural circuit diagram of the electric energy storage system when the power switching device is in a second position. 
         FIG.  24    is a perspective schematic view of an electric energy storage system of the disclosure. 
         FIG.  25    is a schematic structural view of the power switching device in  FIG.  24    from another angle. 
         FIG.  26    is a schematic exploded structural view of the power switching device in  FIG.  25   . 
         FIG.  27    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  26   . 
         FIG.  28    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  27    from another angle. 
         FIG.  29    is a schematic assembled structural view of the power switching assembly, the plug and the energy unit in  FIG.  27   . 
         FIG.  30    is a perspective schematic view of an electric energy storage system of the disclosure. 
         FIG.  31    is a perspective schematic view of the power switching device in  FIG.  30    from another angle. 
         FIG.  32    is a schematic exploded structural view of the power switching device in  FIG.  31   . 
         FIG.  33    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  32   . 
         FIG.  34    is a schematic assembled structural view of the power switching assembly, the plug and the energy unit in  FIG.  32   . 
         FIG.  35    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  31    is in an initial position. 
         FIG.  36    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  31    is in a first position. 
         FIG.  37    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  31    is in a second position. 
         FIG.  38    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  39    is a schematic exploded structural view of the power switching device in  FIG.  38   . 
         FIG.  40    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  39   . 
         FIG.  41    is a schematic structural view of the switching member in the first position in  FIG.  40   . 
         FIG.  42    is a schematic structural circuit diagram of the electric energy storage system in  FIG.  39   . 
         FIG.  43    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  39    is in a first position. 
         FIG.  44    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  39    is in a second position. 
         FIG.  45    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  46    is a perspective schematic view of the power switching device in  FIG.  45    from another angle. 
         FIG.  47    is a schematic exploded structural view of the power switching device in  FIG.  45   . 
         FIG.  48    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  47   . 
         FIG.  49    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  46    is in an initial position. 
         FIG.  50    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  46    is in a first position. 
         FIG.  51    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  46    is in a first position. 
         FIG.  52    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  53    is a perspective schematic view of the power switching device in  FIG.  52    from another angle. 
         FIG.  54    is a schematic exploded structural view of the power switching device in  FIG.  53   . 
         FIG.  55    is a schematic exploded structural view of the power switching assembly in  FIG.  54   . 
         FIG.  56    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  53    is in a first position. 
         FIG.  57    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  56    is in a first position. 
         FIG.  58    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  53    is in a second position. 
         FIG.  59    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  58    is in a second position. 
         FIG.  60    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  61    is a perspective schematic view of the power switching device in  FIG.  60    from another angle. 
         FIG.  62    is a schematic exploded structural view of the power switching device in  FIG.  61   . 
         FIG.  63    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  62   . 
         FIG.  64    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  61    is in a first position. 
         FIG.  65    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  64    is in a first position. 
         FIG.  66    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  61    is in a second position. 
         FIG.  67    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  66    is in a second position. 
         FIG.  68    is a perspective schematic view of an electric energy storage system in the disclosure. 
         FIG.  69    is a perspective schematic view of the power switching device in  FIG.  68    from another angle. 
         FIG.  70    is a schematic exploded structural view of the power switching device in  FIG.  69   . 
         FIG.  71    is a schematic assembled structural view of the power switching assembly and the plug in  FIG.  70   . 
         FIG.  72    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  69    is in a first position. 
         FIG.  73    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  72    is in a first position. 
         FIG.  74    is a schematic circuit diagram of the electric energy storage system when the power switching device in  FIG.  69    is in a second position. 
         FIG.  75    is a schematic structural circuit diagram of the electric energy storage system when the power switching device in  FIG.  74    is in a second position. 
         FIG.  76    is a schematic exploded structural view of a power switching device in an electric energy storage system in the disclosure. 
         FIG.  77    is a schematic structural view of the power switching assembly and the plug in  FIG.  76   . 
         FIG.  78    is a schematic structural view of the electric energy storage system without the power switching device and part of the casing. 
         FIG.  79    is a schematic structural view of the electric energy storage system without the power switching device and part of the casing. 
         FIG.  80    is a perspective schematic view of a power tool system in the disclosure. 
         FIG.  81    is a perspective schematic view of another electric energy storage system of an electric tool system in the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following describes the implementation in the disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects in the disclosure from the content disclosed in this specification. The disclosure can also be implemented or applied through other different specific embodiments, and various details in the specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the disclosure. 
     It should be noted that, the drawings provided in the embodiments only illustrate the basic idea of the disclosure in a schematic manner. The drawings only show the components related to the disclosure instead of the number, shape, and dimension of the components in actual implementation. The form, number, and scale of each component can be changed at will during actual implementation, and the component layout may also be more complicated. 
     As shown in  FIG.  1    to  FIG.  2   , an electric energy storage system is provided in the disclosure. The electric energy storage system includes a first energy unit (not labeled), a second energy unit (not labeled), and a power switching device  11  which is used for achieving electrical energy output. 
     As shown in  FIG.  2   , voltages of the first energy unit and the second energy unit may be nV, and the first energy unit can include a positive electrode  12   a  and a negative electrode  12   b  for electrical energy output. The second energy unit can include a positive electrode  13   a  and a negative electrode  13   b  for electrical energy output. The electric energy storage system further includes a casing  2  for housing the first energy unit and the second energy unit. The positive electrodes  12   a ,  13   a  and the negative electrodes  12   b ,  13   b  are disposed in the casing  2  and exposed to outside of the casing  2  so as to be connected to the power switching device  11 , and in the disclosure, the positive electrodes  12   a ,  13   a  and the negative electrodes  12   b ,  13   b  may have at least 3 types of arrangement structures. 
     As shown in  FIG.  1   , the power switching device  11  is a switching device moving between the first position and the second position while is pressed. The power switching device  11  can include a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113 . The power switching assembly  113  is adjustable and can be connected to the plug  112 . 
     As shown in  FIG.  1   , the housing  111  is provided with a housing space (not labeled) for accommodating the plug  112  and the power switching assembly  113 . The plug  112  includes a first plug member  1121  and a second plug member  1122  for electrically connecting the first energy unit and the second energy unit, and an output terminal  1123  for realizing electrical energy output. The first plug member  1121 , the second plug member  1122  and the output terminal  1123  are all connected and installed in the housing space. 
     As shown in  FIG.  3   , each of the first plug member  1121  and the second plug member  1122  may include a positive terminal ( 1121   a ,  1122   a ) and a negative terminal ( 1121   b ,  1122   b ). The output terminal  1123  may include a positive output terminal  1123   a  and a negative output terminal  1123   b . The output terminal  1123  is connected to the first plug member  1121  and the second plug member  1122  individually, that is, the positive terminal  1121   a  of the first plug member  1121  or the positive terminal  1122   a  of the second plug member  1122  is electrically connected to the positive output terminal  1123   a  of the output terminal  1123 , the negative terminal  1121   b  of the first plug member  1121  or the negative terminal  1122   b  of the second plug member  1122  is electrically connected to the negative output terminal  1123   b  of the output terminal  1123  to ensure that the power supply devices is connected to the first plug member  1121  and the second plug member  1122  to realize the output of electrical energy through the output terminal  1123 . 
     As shown in  FIGS.  1  and  3   , the positive terminals and the negative terminals  1121   a ,  1122   a ,  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122  may be male plugs arranged in a sheet shape, and ends of each male plug are located on the same line. Two terminals with the same polarity of the first plug member  1121  and the second plug member  1122  are arranged side by side; further, the output terminal  1123  is a female plug arranged substantially parallel to the first plug member  1121  and the second plug member  1122 . The output terminal  1123  and the first plug member  1121  and the second plug member  1122  respectively are arranged on two different side walls of the housing  111 , so as to facilitate the connection of the first plug member  1121 , the second plug member  1122  and the output terminal  1123 . 
     As shown in  FIG.  3   , the positive terminals  1121   a ,  1122   a  and negative terminals  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122  can also be arranged in front and back or up and down, etc., which is different from the linear arrangement. And the configuration of the first plug member  1121 , the second plug member  1122 , and the output terminal  1123  can be adjusted according to the specific structure of the power switching assembly  113 ; that is, in the disclosure, the arrangement form and setting form of the first plug member  1121 , the second plug member  1122  and the output terminal  1123  can be selected according to actual needs. 
     As shown in  FIGS.  4  to  5   , the power switching assembly  113  includes a switching member (also referred to as switcher)  114  and a control member (also referred to as controller)  115 . The switching member  114  is used to electrically connect the first plug member  1121  and the second plug member  1122  and can switch the electrical coupling form of the first plug member  1121  and the second plug member  1122 . Specifically, the switching member  114  is housed in the housing  111 , and the housing  111  is provided with a rail/chute structure (not shown) for housing the switching member  114 , and the switching member  114  is slidably connected in the track/chute structure and can move between the first position and the second position along the track/chute structure under the action of the control member  115 . Furthermore the switching member  114  can adjust the coupling form of the first plug member  1121  and the second plug member  1122 . 
     As shown in  FIG.  5   , the switching member  114  includes an elastic member  1141 , a first switching member  1142  and a second switching member  1143 . The first switching member  1142  and the second switching member  1143  are connected by an elastic member  1141 . The first switching member  1142  is provided with a first connection end  1144  and a protrusion (not numbered) for connecting the elastic member  1141 . The first connection end  1144  can include a first connecting portion  1144   a  for connecting the first plug member  1121  and/or the second plug member  1122  and a second connecting portion  1144   b  extending toward the second switching member  1143  so as to connect the second switching member  1143 . 
     As shown in  FIG.  5   , the second switching member  1143  can include substantially the same structure as the first switching member  1142 , that is, the second switching member  1143  is provided with a second connection end  1145  and a protrusion (not labeled) toward the first switching member  1142 . The second connection end  1145  can also include a third connecting portion  1145   a  for connecting the first plug member  1121  and/or the second plug member  1122  and a fourth connecting portion  1145   b  extending toward the first switching member  1142  so as to connect the first switching member  1142 . Preferably, the first connection end  1144  and the second connection end  1145  are both integrally formed, and are in an “L” shape and respectively wrapped on outer walls of the first switching member  1142  and the second switching member  1143 . 
     As shown in  FIGS.  5 - 7   , the elastic member  1141  is connected between the first switching member  1142  and the second switching member  1143  by a protrusion. It is defined that when the elastic member  1141  is in a natural extension state, the switching member  114  is in a first position; when the switching member  114  is in the first position, the first connecting portion  1144   a  of the first connection end  1144  and the negative terminals  1121   b  and  1122   b  of the first plug member  1121  and the second plug member  1122  are electrically connected, so as to make the positive electrodes  12   a  and  13   a  of the first energy unit and the second energy unit be electrically connected; the positive terminals  1121   a  and  1122   a  of the first plug member  1121  and the second plug member  1122  are electrically connected through the third connecting portion  1145   a  of the second switching member  1143 , so as to make the negative electrodes  12   b  and  13   b  of the first energy unit and the second energy unit are electrically connected. At this time, the second connecting portion  1144   b  is arranged separately to the fourth connecting portion  1145   b.    
     As shown in  FIGS.  8 - 9   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  or the positive terminal  1122   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1121   b  or the negative terminal  1122   b  through an electrical connection structure such as a wire, so that the first energy unit and the second energy unit are connected in parallel, and a low voltage (ie, nV) output is realized through the output terminal  1123 . 
     As shown in  FIGS.  6  and  10   , when the elastic member  1141  is in a compressed state under the control of the control member  115 , the switching member  114  is in a second position, and thereby when the switching member  114  is in the second position, the second connecting portion  1144   b  of the first switching member  1142  is connected to the fourth connecting portion  1145   b  in the second switching member  1143 , so that the first switching member  1142  and the second switching member  1143  are connected into one conductive unity through the second connecting portion  1144   b  and the fourth connecting portion  1145   b . Two adjacent terminals of the first plug member  1121  and the second plug member  1122  with opposite polarities are electrically connected through the first switching member  1142  and the second switching member  1143 , that is, at this time, the first connecting portion  1144   a  is separated from the positive terminal  1121   a  of the first plug member  1121 , the third connecting portion  1145   a  is separated from the negative terminal  1122   b  of the second plug member  1122 , and the adjacent negative terminal  1121   b  and positive terminal  1122   a  are electrically connected through the first connecting portion  1144   a , the third connecting portion  1145   a , and the assembly of the second connecting portion  1144   b  and the fourth connecting portion  1145   b.    
     As shown in  FIGS.  11 - 12   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  through an electrical connection structure such as a wire, and the negative output terminal  1123   b  is electrically connected to the negative terminal  1122   b  through an electrical connection structure such as a wire. In this way, the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIGS.  4  and  13   , the control member  115  is used to drive the switching member  114  to move in the track/chute structure, so that the switching member  114  can be switched between the first position and the second position. The control member  115  includes a switching button  116 , a reset button  117 , and a rotary shaft  118 . The rotary shaft  118  is used for connecting the switching button  116  and the reset button  117  back and forth. 
     As shown in  FIG.  13   , the switching button  116  is used to control the switching member  114  to slide between the first position and the second position. The switching button  116  can include an initial position corresponding to the first position and a switching position corresponding to the second position. Further, the switching button  116  includes a pressing portion and a switching portion  1161  connected to the pressing portion. The pressing portion penetrates the housing  111  to drive the switching portion  1161  to move between the initial position and the switching position under the pressing action. 
     As shown in  FIG.  13   , the switching portion  1161  is formed to extend outward along an extension direction perpendicular to the pressing portion. The switching portion  1161  can include two snapping arms  1162 . The two snapping arms  1162  extend toward the switching member  114 , and are arranged parallel to each other. A distance between the two snapping arms  1162  is smaller than a length of the switching member  114  at the first position. 
     As shown in  FIGS.  4  and  13   , when the switching button  116  is in the initial position, the two snapping arms  1162  are both located above the switching member  114 , and the switching member  114  is in the first position; when the switching button  116  is moved to the switching position while is pressed, the switching member  114  is snapped between the two snapping arms  1162 , and is in the second position. 
     As shown in  FIGS.  4  and  13   , an end of each snapping arm  1162  is provided with an inclined guide surface  1163  facing the switching member  114 , and the first switching member  1142  and the second switching member  1143  are provided with a resisting surface  1146  corresponding to the inclined guide surface  1163 . In this way, when the switching button  116  is pressed to move from the initial position to the switching position, the snapping arms  1162  can slide along the inclined guide surface  1163  and two away side walls of the first switching member  1142  and the second switching member  1143 , and is snapped on two away side walls of the switching member  114  in the longitudinal direction. 
     As shown in  FIG.  13   , two away side walls of the first switching member  1142  and the second switching member  1143  are both provided with position limiting structures  1147 , and the snapping arms  1162  is provided with positioning structures  1164  corresponding to the limiting structures  1147 . With this arrangement, when the switching button  116  is moved to the switching position, the separation of the switching button  116  and the switching member  114  can be effectively prevented, and the clamping stability between the switching button  116  and the switching member  114  can be ensured. The limiting structure  1147  is a limiting groove, and the positioning structure  1164  is a positioning protrusion corresponding to the limiting groove. 
     As shown in  FIG.  4   , the reset button  117  penetrates through the housing  111  to control the switching button  116  from the switching position back to the initial position by the rotary shaft  118  while is pressed. The rotating shaft  118  is partially housed in the housing space of the housing  111 , and the rotating shaft  118  includes a positioning shaft, a first fin and a second fin. The positioning shaft is rotatably fixed in the housing  111 . The first fin and the second fin extend outward from a radial direction of the positioning shaft and are located on the same plane. The switching button  116  is provided with a first resisting groove corresponding to the first fin, and the reset button  117  is provided with a second resisting groove corresponding to the second fin. 
     As shown in  FIG.  4   , when the switching button  116  is in the initial position, the rotary shaft  118  is in a freely rotating state, and the reset button  117  can move up and down along its extension direction; and at this time, the switching member  114  is in the first position, and the first energy unit and the second energy unit are connected in parallel, and the electric energy storage system  10  can realize a low voltage (i.e., nV) output. 
     As shown in  FIGS.  4  and  13   , when the switching button  116  moves from the initial position to the switching position, the first resisting groove drives the first fin to rotate around the positioning shaft, so that the second fin abuts against the second resisting groove, so as to drive the reset button  117  and the switching button  116  to move in opposite directions. When the switching button  116  is positioned at the switch position, the switching portion  1161  of the switching button  116  is snapped at both ends of the switching member  114  in the longitudinal direction, and the positioning structure  1164  on the snapping arm  1162  and the limiting structure on the switching member  114  are snapped each other to limit the switching position of the switching button  116  and drive the switching member  114  to move from the first position to the second position. The reset button  117  is snapped and positioned between the housing  111  and an end of the second fin, and At this time, the switching member  114  is in the second position, the first energy unit and the second energy unit are connected in series, and the electric energy storage system can realize a high-voltage (i.e., 2nV) output. 
     As shown in  FIGS.  4  and  13   , when controlling the switching button  116  to move back to the initial position, the reset button  117  is pressed, and drives the second fin and the first fin through the second resisting groove to rotate around the positioning shaft, the first fin drives the switching button  116  to move from the switching position to the initial position, so that the limiting structure is separated from the positioning structure. The switching portion  1161  is disengaged from an end of the switching member  114 , which further drives the switching member  114  to move from the second position back to the first position, and the switching of the coupling state of the first plug member  1121  and the second plug member  1122  by the power switching assembly  113  is completed. 
     As shown in  FIGS.  2  and  14   , an electric energy storage system is further provided in the disclosure. The electric energy storage system can include substantially the same structure as the previous embodiment. The difference is that the power switching device  11  is a switching device that can realize the switching between the first position and the second position by rotating a turntable. The following description will describe the differences in detail, and the similar/same parts will not be repeated here. 
     As shown in  FIGS.  15 - 16   , the power switching device  11  can include a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113 . The power switching assembly  113  is adjustable and connected to the plug  112 . Similarly, the plug  112  includes a first plug member  1121  and a second plug member  1122  for electrically connecting the first energy unit and the second energy unit, and an output terminal  1123  for realizing electrical energy output, and each of the first plug member  1121  and the second plug member  1122  can include a positive terminal ( 1121   a ,  1122   a ) and a negative terminal ( 1121   b ,  1122   b ), and the output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIG.  16   , the power switching assembly  113  includes a switching member (not labeled) and a control member (not labeled). The switching member is used to be electrically connected between the first plug member  1121  and the second plug member  1122 , and can switch coupling form of the first plug member  1121  and the second plug member  1122 . Specifically, the switching member is housed in the housing  111 , and can be rotated in the housing  111  and moved between the first position and the second position under the action of the control member, so as to further adjust the coupling form of the first plug member  1121  and the second plug member  1122 . 
     As shown in  FIG.  16   , the switching member includes a first switching member  1142  and a second switching member  1143 . The first switching member  1142  is connected to the control member. The second switching member  1143  is electrically connected to the plug  112 . The first switching member  1142  can be driven by the control member to rotate around the axis of the control member, so as to switch the connection form of the plug  112  in a coupled state. 
     As shown in  FIGS.  16 - 17   , the first switching member  1142  penetrates the control member, and can include a connecting portion (not labeled) for connecting the second switching member  1143  and a transmission portion (not labeled) for power transmission. The connecting portion exposes out from a lower surface of the control member to be electrically connected to the second switching member  1143 . The transmission portion protrudes outward from an upper surface of the control member to be electrically connected to the output terminal  1123 , and realizes the transmission of electric energy. 
     As shown in  FIG.  16   , a plurality of first switching members  1142  are provided at the same time, and the plurality of first switching members  1142  are arranged on the control member in a staggered manner, so as to realize the switching of the coupling form of the first plug member  1121  and the second plug member  1122 . In the disclosure, the first switching member  1142  is provided with at least two structures for being electrically connected to the second switching member  1143 . And in this embodiment, the first switching member  1142  is provided with a first switching sub-member  1142   a  with a long-circle connecting portion and a second switching sub-member  1142   b  with a circle connecting portion. An extension height of the transmission portion of the first switching sub-member  1142   a  is higher than an extension height of the transmission portion of the second switching sub-member  1142   b , so that the extensions of the first switching sub-member  1142   a  and the second switching sub-member  1241   b  are arranged in an up-and-down position, and the output terminal  1123  realizes the output of electric energy. 
     As shown in  FIG.  17   , the second switching member  1143  can include a connection end  1243  for connecting the plug  112 , a chassis  1244  for fixing the connection end  1243 , and supporting portions  1245  for supporting the connection end  1243  and the chassis  1244 . One end of the connection end  1243  is electrically connected to the plug  112 , and another end penetrates the chassis  1244  and exposed on a side of the chassis  1244  facing the first switching member  1142  to be electrically connected to the first switching member  1142 . 
     As shown in  FIG.  19   , the connection end  1243  is provided with a first connection end  1243   a , a second connection end  1243   b , a third connection end  1243   c , and a fourth connection end  1243   d  that are disposed in a staggered manner and in a direction perpendicular to the chassis  1244 , and the four connection ends  1243  are electrically connected to the positive terminal  1121   a , the negative terminal  1121   b , the positive terminal  1122   a , and the negative terminal  1122   b  respectively. Further, each connection end  1243  can include two contacts, the two contacts is located on a end that penetrates the chassis  1244  and is exposed on one side of the chassis  1244  close to the first switching member  1142 . The contacts on different connection ends  1243  are arranged in a staggered manner. 
     As shown in  FIGS.  18 - 19   , the supporting portions  1245  may be evenly distributed on the bottom of the chassis  1244 . The chassis  1244  is in a round-shape, and the supporting portions  1245  can be provided with six at the same time, and the six supporting portions  1245  are evenly arranged along the circumference of the chassis  1244 , so as to support the chassis  1244  and make the connection ends  1243  electrically connect the plug  112 . 
     As shown in  FIG.  18   , the control member is provided with a switching button  116  penetrating through the housing  111  and a trigger unit  127  housed in the housing  111 . The trigger unit  127  is connected to the switching button  116  to drive the switching member connected to the trigger unit  127  to rotate. 
     As shown in  FIG.  17   , the switching button  116  is arranged in a cylindrical-shape. The trigger unit  127  and the switching button  116  are integrally formed. The first switching member  1142  is connected and installed on the trigger unit  127 . The first switching sub-member  1142   a  and the second switching sub-member  1142   b  are disposed on the trigger unit  127  in a staggered manner. In this embodiment, the trigger unit  127  and the chassis  1244  are both arranged in a circular plate shape. Further, the trigger unit  127  is provided with a limiting slot  127   a , and the chassis  1244  of the second switching member  1143  is provided with a limiting protrusion  1246  corresponding to the limiting slot  127   a . The limiting protrusion  1246  is received in the limiting slot  127   a  and slidable in the limiting slot  127   a , so as to limit the moving position and distance of the first switching member  1142 , control the first switching member  1142  to switch between the first position and the second position, and further ensure the stable connection between the connection end  1243  of the first switching member  1142  and the second switching member  1143 . 
     Furthermore, the trigger unit  127  is further provided with a clamping portion  127   b . The clamping portion  127   b  is snapped and fixed with the housing  111 . The control member is rotatably connected with the housing  111  through the clamping portion  127   b , so as to limit the rotation position of the switching button  116 . 
     As shown in  FIGS.  15 - 16   , the control member may include, for example, three switching positions. The three switching positions include the first position and the second position where the first plug member  1121 , the second plug member  1122  and the output terminal  1123  are connected to achieve electrical energy output, and the initial position where the plug  112  of the power switching device  11  is in an open circuit state. 
     As shown in  FIG.  16   , when the power switching device  11  is in the initial position, any one of the first switching members  1142  cannot be connected to different plugs  112  at the same time. At this time, there is no coupling connection relationship between the first plug member  1121  and the second plug member  1122 . The first energy unit and the second energy unit are in an open circuit state, and the electric energy storage system has no energy output. 
     As shown in  FIG.  16   , when the power switching device  11  is in the first position, the first switching member  1142  is driven by the trigger unit  127  to rotate on the chassis  1244 , and is coupled and connected to the positive terminals  1121   a ,  1122   a , and the negative terminals  1121   b ,  1122   b  through the cooperation of the connecting portion and the connection end  1243 . 
     As shown in  FIGS.  20 - 22   , when the power switching device  11  is in the first position, the contacts of the first connection end  1243   a  and the third connection end  1243   c  are electrically connected to the positive terminals  1121   a  and  1122   a  through the first switching sub-member  1142   a , the second connection end  1243   b  and the fourth connection end  1244   d  are electrically connected to the negative terminals  1121   b  and  1122   b  through another first switching sub-member  1142   a . At this time, the first energy unit and the second energy unit are connected in parallel through the switching member and further realize a low voltage (i.e., nV) output through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  20 - 23   , when the power switching device  11  is in the second position, the first switching member  1142  is driven by the trigger unit  127  to rotate on the chassis  1244 , and is coupled and connected to the positive terminals  1121   a ,  1122   a  and the negative terminals  1121   b ,  1122   b  through the cooperation of the connecting portion and the connection end  1243 . When the power switching device  11  is in the second position, the contacts of the second connection end  1243   b  and the third connection end  1243   c  are electrically connected to the positive terminal  1122   a  and negative terminal  1121   b  through the first switching sub-member  1142   a ; the contact of the first connection end  1243   a  is electrically connected to the positive terminal  1121   a  and the positive output terminal  1123   a  through the second switching sub-member  1142   b ; the contact of the fourth connection end  1243   d  is electrically connected to the negative terminal  1122   b  and the negative output terminal  1123   b  through the second switching sub-member  1142   b . At this time, the first energy unit and the second energy unit are connected in series through the switching member, and further realize a high-voltage (i.e., 2nV) output through the output terminal  1123 . 
     As shown in  FIGS.  2  and  24   , an electric energy storage system is further provided in the disclosure. The electric energy storage system has substantially the same structure as the previous embodiment. The difference is that the power switching device  11  realizes position switching of the first position and the second position by reciprocating the switching button (also referred as relative rotation of the switching button). The following description will describe the differences in detail, and the similar/same parts will not be repeated here. 
     As shown in  FIGS.  25  to  26   , the power switching device  11  is provided with a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113 . The power switching assembly  113  is adjustable and connected to the plug  112 . Similarly, the plug  112  includes a first plug member  1121  and a second plug member  1122  for electrically connecting the first energy unit and the second energy unit, and an output terminal  1123  for realizing electric energy output. The first plug member  1121 , the second plug member  1122  are provided with positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ), and the output terminal  1123  is provided with a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  26 - 27   , the power switching assembly  113  includes a switching member  114  and a control member  115 . The switching member  114  is used to electrically connect the first plug member  1121  and the second plug member  1122 . The switching member  114  can switch a coupling form of the first plug member  1121  and the second plug member  1122 . Specifically, the switching member  114  is housed in the housing  111 , and the switching member  114  is rotatably housed in the housing  111  through a rotating shaft  1341 , and can rotate around the rotating shaft  1341  and swing between the first position and the second position under the action of the control member  115 , so as to further adjust the coupling form of the first plug member  1121  and the second plug member  1122 . 
     As shown in  FIG.  27   , the power switching assembly  113  further includes an intermediate connecting member  136 . The intermediate connecting member  136  is used for connecting the switching member  114  with the first plug member  1121 , the second plug member  1122 , and the output terminal  1123 , and the switching member  114  is rotatably connected in the intermediate connecting member  136  through the rotating shaft  1341 . The intermediate connecting member  136  is provided with many intermediate connecting plates for connecting the first plug member  1121 , the second plug member  1122  and/or the output terminal  1123 . Each of intermediate connecting plates may be a metal intermediate connecting member made of conductive metal material. In addition, the switching member  114  is electrically connected to the first plug member  1121 , the second plug member  1122 , and the output terminal  1123  through the metal intermediate connecting member, so as to realize the power transmission of the power switching device  11 . 
     As shown in  FIGS.  27 - 28   , the switching member  114  is a plate with a certain arc. The plate with a certain arc may be a warping plate or an arc-shaped plate, so that the plane where the switching member  114  is located on intersects the plane where the intermediate connecting member  136  is located on. The plane of. In this embodiment, the switching member  114  is driven by the power switching assembly  113  to rotate around the rotating shaft  1341 , and both ends of the switching member  114  abut on the intermediate connecting member  136  and/or the assembly of the first plug member  1121  and the second plug member  1122 , so as to realize the switching of the coupling form of the first plug member  1121  and the second plug member  1122 . Further, an end of the switching member  114  is provided with protrusions ( 1342   a ,  1342   c ) for improving the electrical contact performance, and the protrusions are respectively disposed corresponding to the positive terminals  1121   a  and  1122   a  and the negative terminals  1121   b  and  1122   b  of the first plug member  1121  and the second plug member  1122 . 
     As shown in  FIGS.  27 - 28   , the switching member  114  includes a first switching member  1142  and a second switching member  1143 . The first switching member  1142  and the second switching member  1143  are arranged in parallel and side by side. The first switching member  1142  and the second switching member  1143  is fixedly connected through an arc-shaped connecting portion (not labeled), so that the switching member  114  is generally arranged in an “H” shape. Further, there are many protrusions and they are respectively located at the end of each switching member  114 , and the protrusions on the same switching member  114  are symmetrically arranged related to the rotation axis of the rotating shaft  1341 . 
     As shown in  FIGS.  27 - 29   , the control member  115  can rotate in the housing  111  to drive the switching member  114  to move between the first position and the second position. The control member  115  is a warping member arranged in a warping switch structure corresponding to the switching member  114 . The control member  115  includes a switching button  116  provided on the housing  111 , a trigger unit  127  provided corresponding to the switching button  116 , and a driving section  139  that abuts against the switching member  114 . The switching button  116  is movably arranged on the housing  111 , and the trigger unit  127  is fixed in the housing space of the housing  111  through a rotating shaft  1381 , and is located below the switching button  116 , so that the switching button  116  drives the trigger unit  127  to rotate around the shaft  1381 . Further, the axis of the rotating shaft  1381  of the trigger unit  127  and the axis of the rotating shaft  1341  of the switching member  114  are located in the same plane or respectively located in two mutually parallel planes. 
     As shown in  FIGS.  27 - 28   , one end of the driving portion  139  abuts against the switching member  114 , the other end is connected to the trigger unit  127 , and the end of the driving portion  139  abutting against the switching member  114  is arranged in an arc-shape to ensure the driving portion  139  can closely abut against the arc-shaped connecting portion of the switching member  114  and drive the switching member  114  to rotate. 
     As shown in  FIGS.  27 - 28   , the trigger unit  127  includes a receiving hole (not shown) for accommodating the driving portion  139 , and an elastic element (not shown) is disposed between the trigger unit  127  and the driving portion  139  and elastically connected to the trigger unit  127  and the driving portion  139 . In this way, when the control member  115  abuts against the switching member  114 , the driving portion  139  abuts against the switching member  114  along a side away from the trigger unit  127  under the action of the elastic element, so that the end/protrusion  1342  of the switching member  114  abuts and is tightly snapped on the plug  112 /the intermediate connecting member  136  to ensure the stability of the power transmission of the power switching device  11  in the process of the rotation of the switching member  114  driven by the control member  115 . 
     As shown in  FIGS.  26 - 27   , the control member  115  can include an initial position and a switching position corresponding to the first position and the second position. The switching position can be defined as a first switching position when the control member  115  controls the switching member  114  in the first position, the switching position can be defined as a second switching position when the control member  115  controls the switching member  114  in the second position. 
     As shown in  FIGS.  25  and  28   , when the switching button  116  is in the initial position, the driving portion  139  abuts on the central axis of the switching member  114 , so that the switching member  114  does not deflect and contact the plug  112 . The positive electrodes  12   a ,  13   a  and the negative electrodes  12   b ,  13   b  of the first energy unit and the second energy unit connected to the plug  112  are in a disconnected state, and the electric energy storage system cannot transmit electrical energy out. 
     As shown in  FIGS.  27 - 29   , when the switching member  114  is rotated to the first switching position under the resistance of the control member  115 , a first protrusion  1342   a  on the first switching member  1142  abuts on the intermediate connecting member  136   a , The first protrusion  1344   b  on the second switching member  1143  abuts on the intermediate connecting member  136   d , and further, the intermediate connecting member  136   a  and the intermediate connecting member  136   d  are respectively electrically connected to the intermediate connecting member  136   c  and the intermediate connecting member  136   b  under the action of the resisting force of the switching member  114 , so that the positive terminal  1121   a  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122  are electrically connected, and the negative terminal  1121   b  of the first plug member  1121  and the negative terminal  1122   b  of the second plug member  1122  are electrically connected. 
     As shown in  FIG.  29   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  or the positive terminal  1122   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1121   b  or the negative terminal  1121   b  through an electrical connection structure such as a wire, so that the first energy unit and the second energy unit are connected in parallel, and a low voltage (i.e., nV) output is realized through the output terminal  1123 . 
     As shown in  FIG.  29   , when the switching member  114  is rotated to the second switching position under the resistance of the control member  115 , the second protrusion  1342   c  of the first switching member  1142  and the second protrusion  1344   d  of the second switching member  1143  both abut on the intermediate connecting member  136   e , and further electrically connected to the positive terminal  1122   a  of the second plug member  1122  and the negative terminal  1121   b  of the first plug member  1121  through the intermediate connecting member  136   b  and the intermediate connecting member  136   c.    
     As shown in  FIG.  29   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1122   b  through an electrical connection structure such as a wire, so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIG.  2    and  FIG.  30   , an electric energy storage system is provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by swinging. The following description will focus on the difference; the same or similar content will not be repeated here. 
     As shown in  FIGS.  31 - 32   , the power switching device  11  also includes a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  112 . Similarly, the plug  112  includes a first plug member  1121  and a second plug member  1122  for electrically connecting the first energy unit and the second energy unit, and an output terminal  1123  for realizing electrical energy output. The first plug member  1121  and the second plug member  1122  have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ), and the output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  32  to  33   , the power switching assembly  113  includes a control member  115  and a switching member  114 . The control member  115  includes a switching button  116  disposed on the housing, and an intermediate connecting member  136  disposed corresponding to the trigger unit  127 . In this embodiment, the switching button  116  and the trigger unit  127  are integrally formed, and the switching button  116  partially penetrates the housing  111  and is snapped in the receiving space through the trigger unit  127 . The trigger unit  127  is provided with a limiting pillar  1481  protruding along the extension direction of the switching button  116 , and the housing  111  is provided with a resisting pillar (not shown) corresponding to the limiting pillar  1481 . When the switching button  116  is rotated, the switching button  116  can be limited to a fixed position under the action of the limiting pillar  1481  and the resisting pillar, so as to prevent the switching member  114  connected to the control member  115  from swinging freely between the first position and the second position. 
     As shown in  FIG.  32   , the intermediate connecting member  136  is provided with connecting holes (not labeled) in a staggered manner, and in this embodiment, the intermediate connecting member  136  is an insulating intermediate connecting member made of insulating material. Further, the positive terminals  1121   a ,  1122   a , the negative terminals  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122  all are provided with connecting portions (not labeled) corresponding to the connecting holes. The connecting portions of the positive terminals  1121   a ,  1122   a , and the negative terminals  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122  are exposed to the surface of the intermediate connecting member  136  facing the trigger unit  127  through the connecting holes. The positive terminal  1121   a  and the negative terminal  1121   b  of the first plug member  1121 , the positive terminal  1122   a  and the negative terminal  1122   b  in the second plug member  1122  are respectively arranged on two sides of the intermediate connecting member  136 . 
     As shown in  FIGS.  32 - 33   , the switching member  114  is provided at one end of the trigger unit  127  close to the intermediate connecting member  136 , and can be rotated around the trigger unit  127  under the action of the switching button  116 , so as to move between the first position and the second position. Further, the switching member  114  includes a first switching member  1142  and a second switching member  1143 , the first switching member  1142  and the second switching member  1143  are separately and symmetrically arranged on both sides of the trigger unit  127 . In this embodiment, each switching member  114  can include first ends  1453   a ,  1453   b  and the second ends  1453   c ,  1453   d  formed from the first ends  1453   a ,  1453   b  extending outward, and the distance between the two first ends  1453   a ,  1453   b  is smaller than the distance between the two second ends  1453   c ,  1453   d , so that a substantially Y-shaped gap is formed between the switching member  1142  and the second switching member  1143 . 
     As shown in  FIGS.  34 - 35   , the switching member  114  can also include an initial position, a first switching position corresponding to the first position, and a second switching position corresponding to the second position. When the switching member  114  is in the initial position, the switching member  114  does not contact the connection portions of the positive terminals  1121   a ,  1122   a  and the negative terminals  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122 . The positive electrodes  12   a ,  13   a  and the negative electrodes  12   b ,  13   b  of the energy unit and the second energy unit connected to the plug  112  are in an open circuit state, and the electric energy storage system cannot output electrical energy. 
     As shown in  FIGS.  34 - 36   , when the switching member  114  is rotated to the first switching position under the action of the control member  115 , the first end  1453   a  and the second end  1453   c  of the first switching member  1142  are respectively connected to the positive terminal  1121   a  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122  through the connecting portions, and the first end  1453   b  and the second end  1453   d  of the second switching member  1143  are respectively connected to the negative terminal  1121   b  of the first plug member  1122  and the negative terminal  1122   b  of the second plug member  1122  through the connecting portions. 
     As shown in  FIGS.  35 - 36   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  or the positive terminal  1122   a  through an electrical connection structure such as a wire, and the negative output terminal  1123   b  is electrically connected to the negative terminal  1121   b  or the negative terminal  1122   b  through an electrical connection structure, such as a wire. Therefore, the first energy unit and the second energy unit are connected in parallel, and a low voltage (i.e., nV) output is achieved through the output terminal  1123 . 
     As shown in  FIGS.  34  and  37   , when the switching member  114  is rotated to the second switching position under the action of the control member  115 , the first end  1453   b  and the second end  1453   d  of the second switching member  1143  are respectively connected to the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122  through the connecting portion. At least one of the first end  1453   a  and the second end  1453   c  of the first switching member  1142  rotates along the plane where the intermediate connecting member  136  is located on, and does not contact the connecting portion of the intermediate connecting member  136 . 
     As shown in  FIG.  37   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1122   b  through an electrical connection structure such as a wire, so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIG.  2    and  FIG.  38   , an electric energy storage system is provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by sliding. The following description will explain the differences in detail; the same or similar content will not be repeated here. 
     As shown in  FIGS.  39 - 40   , the power switching device  11  can include a housing  111 , a plug  152  accommodated in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  152 . The plug  152  includes a first plug member  1121 , a second plug member  1122 , and an output terminal  1123  for realizing electric energy output, and the first plug member  1121  and the second plug member  1122  have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ). The output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  39 - 40   , the power switching assembly  113  includes a switching member  114  and a control member  115 . The switching member  114  is used to electrically connect/disconnect the first plug member  1121  and the second plug member  1122  and can switch a coupling form of the first plug member  1121  and the second plug member  1122 . Specifically, the switching member  114  is housed in the housing  111 , and the switching member  114  can be driven to slide in the housing  111  and move between the first position and the second positions under the push/pull action of the control member, so as to further adjust the coupling form of the first plug member  1121  and the second plug member  1122 . 
     As shown in  FIG.  40   , the switching member  114  may be a conductive switching member that can be electrically connected, and the control member  115  includes a switching button  116  penetrating the housing  111  and a trigger unit  127  disposed on the switching button  116 . In this embodiment, the trigger unit  127  is formed by extending outward from the end of the switching button  116  housed in the accommodating space along the direction perpendicular to the direction in which the power switching device  11  and the energy unit are plugged (i.e., the plugging direction), and the triggers portion  127  is symmetrically arranged with respect to the central axis of the switching button  116 . 
     As shown in  FIGS.  39 - 40   , the control member  115  has an initial position and a switching position corresponding to the first position and the second position. The switching position when the control member  115  controls the switching member  114  in the first position is defined as the first switching position, the switching position when the control member  115  controls the switching member  114  in the second position is defined as the second switching position. 
     As shown in  FIG.  39   , the trigger unit  127  may be roughly arranged in a “F” shape, and includes a first trigger unit  1271  and a second trigger unit  1272 . The first trigger unit  1271  and the second trigger part  1272  extend perpendicular to the plugging direction and are parallel to each other. The switching member  114  is disposed on the first trigger unit  1271  to switch between the first position and the second position while driven by the switching button  116  and the trigger unit  127 . One side of the second trigger unit  1272  away from the first trigger unit  1271  is provided with an elastic member  1141 . Thereby when the switching button  116  is pushed to control the switching member  114  to switch between the first position and the second position, it is convenient for the control member  115  to return to the initial position from the first switch position or the second switch position. The number of elastic member  1141  may be two, and the two elastic members  1141  are arranged symmetrically about the central axis of the switching button  116 . 
     As shown in  FIG.  39   , in one embodiment, the switching member  114  is provided with at least two conductive sheets arranged in a horizontal plate shape. There are four switching members  114  and the four switching members  114  are arranged side by side along the extension direction of the first trigger unit  1271 ; and in this embodiment each plug  152  can include at least two contacts arranged in parallel in the front and back along the plugging direction. The first plug member  1121  includes two negative terminals  1121   b  and three positive terminals  1121   a . The two negative terminals  1121   b  and three positive terminals  1121   a  are arranged in a staggered manner in the left and right along the plugging direction, and any two of the three positive terminals  1121   a  are arranged side by side or in parallel. The second plug member  1122  includes two positive terminals  1122   a  and two negative terminals  1122   b . The two positive terminals  1122   a  are arranged in a staggered manner in the left and right along the plugging direction, the two negative terminals  1122   b  are arranged forward and backward in the plugging direction (as shown in  FIG.  42   ). In this way, when the switching member  155  is switched between the first position and the second position under the action of the control member  115 , the switching member  114  can electrically connect to the contacts on different plugs  152  to further control the coupling form among the plugs  152 . 
     As shown in  FIGS.  40 - 41   , when the control member  115  is in the first switching position, the switching member  114  is in the first position. At this time, the first switching member  1142  is electrically connected to the negative terminals  1121   b ,  1122   b  of the first plug member  1121  and the second plug member  1122 ; the second switching member  1143  is electrically connected to the positive terminals  1121   a ,  1122   a  of the first plug member  1121  and the second plug member  1122 ; the third switching member  1144  is electrically connected to the positive terminal  1121   a  of the first plug member  1121  and the positive output terminal  1123   a  of the output terminal  1123 ; the fourth switching member  1145  is electrically connected to the negative terminal  1122   b  of the second plug member  1122  and the negative output terminal  1123   b  of the output terminal  1123 . At this time, the first energy unit and the second energy unit are connected in parallel through the switching member  114 , and further a lower-voltage (i.e., nV) output is realized through the output terminal  1123 . 
     As shown in  FIGS.  39 - 44   , when the control member  115  is in the second switching position, the switching member  114  is in the second position. At this time, the first switching member  1142  is electrically connected to the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122 . The second switching member  1143  is in a blank position and is not electrically connected to any positive and negative terminals. The third switching member  1144  is electrically connected to the positive terminal  1121   a  of the first plug member  1121  and the positive output terminal  1123   a  of the output terminal  1123 . The fourth switching member  1145  is electrically connected to the negative terminal  1122   b  of the second plug member  1122  and the negative output terminal  1123   b  of the output terminal  1123 . At this time, the first energy unit and the second energy unit are connected in series through the switching member  114 , and further a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIGS.  2  and  45   , an electric energy storage system is provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by sliding. 
     As shown in  FIGS.  46 - 47   , the power switching device  11  includes a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  112 . The plug  112  includes a first plug member  1121 , a second plug member  1122 , and an output terminal  1123  for realizing electrical energy output. The first plug member  1121  and the second plug member  1122  may have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ), The output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  46 - 47   , the switching member  114  may be a conductive switching member. The control member  115  can include a switching button  116  penetrating through the housing  111  and a trigger unit  127  corresponding to the switching button  116 . Furthermore, the trigger unit  127  extends along the plugging direction, and is provided with a first trigger unit  1271  and a second trigger unit  1272  that are parallel to each other for fixedly connecting the switching member  114 . The first trigger unit  1271  and the second trigger unit  1272  is connected through a connecting arm (not labeled), so that the trigger unit  127  is arranged in an “I” shape. The housing  111  is provided with a sliding groove for accommodating the connecting arm, so that the control member  115  can drive the switching member  114  to slide between the first position and the second position. 
     As shown in  FIG.  48   , the first trigger unit  1271  is further provided with elastic members  1141 . The elastic members  1141  are provided on one side of the first trigger unit  1271  away from the second trigger unit  1272 . This arrangement can facilitate the resetting of the trigger unit  127  and the pushing and pulling of the control member  115  to further improve the practicability of the electric energy storage system. 
     As shown in  FIG.  48   , the switching member  114  includes a first switching member  1142 , a second switching member  1143  and a third switching member  1144 . The first switching member  1142  and the second switching member  1143  are disposed on the first trigger unit  1271 , and the third switching member  1144  is disposed on the second trigger unit  1272 . The first switching member  1142 , the second switching member  1143  are arranged oppositely to the third switching member  1144 , and the first switching member  1142 , the second switching member  1143  and the third switching member  1144  are arranged in a “U” shape. 
     As shown in  FIGS.  49 - 50   , the control member  115  can have at least a first switching position corresponding to the first position and a second switching position corresponding to the second position. When the control member  115  is in the first switching position, the switching member  114  is in the first position. At this time, the first switching member  1142  is electrically connected to the positive terminals  1121   a ,  1122   a  of the first plug member  1121  and the second plug member  1122 ; the second switching member  1143  is electrically connected to the negative terminals  1121   b  and  1122   b  of the first plug member  1121  and the second plug member  1122 ; the third switching member  1144  is in a free state. 
     As shown in  FIG.  49 - 50   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  or the positive terminal  1122   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1121   b  or the negative terminal  1122   b  through an electrical connection structure such as a wire; so that the first energy unit and the second energy unit are connected in parallel, and a low voltage (i.e., nV) output is achieved through the output terminal  1123 . 
     As shown in  FIGS.  49  and  51   , when the control member  115  is in the second switching position, the switching member  114  is in the second position. At this time, the first switching member  1142  and the second switching member  1143  are in a free state; The two ends of the third switching member  1144  are respectively connected to the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122 . 
     As shown in  FIG.  51   , the positive output terminal  1123   a  of the output terminal  1123  is electrically connected to the positive terminal  1121   a  through an electrical connection structure such as a wire; the negative output terminal  1123   b  is electrically connected to the negative terminal  1122   b  through an electrical connection structure such as a wire; so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIGS.  2  and  52   , an electric energy storage system is provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by toggling. 
     As shown in  FIGS.  53 - 54   , the power switching device  11  can include a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  112 . The plug  112  includes a first plug member  1121  and a second plug member  1122  and an output terminal  1123  for realizing electric energy output, and the first plug member  1121  and the second plug member  1122  may have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ). The output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  54 - 55   , the control member  115  includes a switching button  116  penetrating through the housing  111  and a trigger unit  127  corresponding to the switching button  116 . The switching member  114  is connected to the trigger unit  127  and is a conductive switching member which can be electrically connected. 
     As shown in  FIG.  55   , the trigger unit  127  can be driven by the switching button  116  to slide left and right in a direction perpendicular to the plugging direction, and further the switching member  114  connected to the trigger unit  127  is driven by the switching button  116  to switch between the first position and the second position. In this embodiment, the switching button  116  includes a sliding block  1761  for connecting the trigger unit  127 . The sliding block  1761  and the switching button  116  are provided separately to facilitate the assembly of the power switch device  11 . Of course, in other embodiments of the disclosure, the sliding block  1761  can also be integrally formed with the switching button  116 . 
     As shown in  FIG.  55   , the trigger unit  127  includes a first trigger unit  1271  and a second trigger unit  1272  arranged in parallel, and each trigger unit  127  can include a convex block (not labeled) for connecting the sliding block  1761 , and the sliding block  1761  are provided with accommodating grooves (not labeled) corresponding to the convex blocks, and the accommodating grooves are arranged in left and right and in a staggered manner along the plugging direction, so that the first trigger unit  1271  and the second trigger unit  1272  are arranged in a staggered manner along the sliding direction of the switching button  116 ; Furthermore, two ends of each trigger unit  127  are connected with elastic members  1141 , which can facilitate the control of the member  115  to toggle. 
     As shown in  FIG.  55   , the switching member  114  includes a first switching member  1142 , a second switching member  1143 , a third switching member  1144 , a fourth switching member and a fifth switching member  1146 . The first switching member  1142  and a second switching member  1143  are connected to the first trigger unit  1271 , and the third switching member  1144 , the fourth switching member  1145  and the fifth switching member  1146  are connected to the second trigger unit  1272 . The first switching member  1142 , the second switching member  1143 , and the fourth switching member  1145  each are provided with “U”-shaped or substantially “U”-shaped connecting portions (not labeled) for connecting the positive terminals and the negative terminals  1121   a ,  1122   a ,  1121   b ,  1122   b , the third switching member  1144  and the fifth switching member  1146  are both arranged in a sheet shape. 
     As shown in  FIGS.  55 - 57   , the control member  115  also has at least a first switching position corresponding to the first position and a second switching position corresponding to the second position. When the control member  115  is in the first switching position, the switching member  114  is in the first position. At this time, the first switching member  1142  is electrically connected to the positive terminals  1121   a ,  1122   a  of the first plug member  1121  and the second plug member  1122 ; the second switching member  1143  is electrically connected to the negative terminals  1121   b  and  1122   b  in the first plug member  1121  and the second plug member  1122 ; the third switching member  1144 , the fourth switching member  1145 , and the fifth switching member  1146  are in a free state; so that the first energy unit and The second energy unit is connected in parallel, and further a low voltage (i.e. nV) output is realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  58 - 59   , when the control member  115  is in the second switching position, the switching member  114  is in the second position. At this time, the first switching member  1142  and the second switching member  1143  are in a free state; two ends of the fourth switching member  1145  are respectively connected to the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122 . The third switching member  1144  is electrically connected to the positive terminal  1121   a  through an electrical connection structure such as a wire; the fifth switching member  1146  is connected to the negative output terminal  1123   b  through an electrical connection structure such as a wire; so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e., 2nV) output is realized through the output terminal  1123 . 
     As shown in  FIG.  2 - 60   , an electric energy storage system is provided in the disclosure. The electric energy storage system can include roughly the same structure as the above-mentioned electric energy storage system. The main difference is that the structure of the power switching device  11  for realizing the switching between the first position and the second position by pushing and pulling is different. 
     As shown in  FIGS.  61 - 62   , the power switching device  11  can include a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  112 . The plug  112  includes a first plug member  1121  and a second plug member  1122 , and an output terminal  1123  for realizing electric energy output, and both the first plug member  1121  and the second plug member  1122  have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ). The output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIGS.  62 - 63   , switching buttons  116  of the control member  115  further includes first switching buttons  116   a  and second switching buttons  116   b  for respectively controlling the movement of the first trigger unit  1271  and the second trigger unit  1272 . 
     As shown in  FIG.  63   , the first switching button  116   a  and the second switching button  116   b  are respectively disposed at one end of the first trigger unit  1271  and the second trigger unit  1272  along vertical plugging direction and located at the same side of the housing  111 . Further, a resisting member  178 ′ is further disposed between the first trigger unit  1271  and the second trigger unit  1272 . The setting of the resisting member  178 ′ can ensure that only one trigger unit  127  is driven by the switching button  116  at the same time. This arrangement can effectively avoid the short circuit of the electric tool and the power supply device connected to the two ends of the power switching device  11  due to misoperation. 
     As shown in  FIG.  62   , the control member  115  can include an initial position, a first switching position corresponding to the first position, and a second switching position corresponding to the second position. When the control member  115  is in the initial position, the switching member  114  is separated from the positive and negative terminals  1121   a ,  1122   a ,  1121   b ,  1122   b , the first energy unit and the second energy unit are both in a disconnected state, and the output terminal  1123  does not output electric energy to the outside. 
     As shown in  FIGS.  64 - 65   , when the control member  115  is in the first switching position, and the switching member  114  is in the first position. At this time, the first energy unit and the second energy unit are connected in parallel through the cooperation of first switching member  1142 , the second switching  1143  and the positive and negative terminals  1121   a ,  1122   a ,  1121   b ,  1122   b , and further a low voltage (i.e. nV) output is realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  66 - 67   , when the control member  115  is in the second switching position, the switching member  114  is in the second position. At this time, the first energy unit and the second energy unit are connected in series through the fourth switching member  1145  and the cooperation of the positive and negative terminals  1121   b  and  1122   a , and further a high-voltage(i.e. 2nV) output is realized through the cooperation of the third switching member  1144 , the fifth switching member  1146 , the positive terminal  1121   a , the negative terminal  1122   b  and the positive and negative outputs  1123   a ,  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  2  and  68   , an electric energy storage system is provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by pulling and pushing. 
     As shown in  FIGS.  69 - 70   , the power switching device  11  includes a housing  111 , a plug  112  housed in the housing  111 , and a power switching assembly  113  that is adjustable and connected to the plug  112 . The plug  112  includes a first plug member  1121  and a second plug member  1122 , and an output terminal  1123  for realizing electric energy output, and both the first plug member  1121  and the second plug member  1122  have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ). The output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIG.  70   , the power switching device  11  includes a switching member  114  for separating two adjacent plugs  112 , and the switching member  114  is, for example, an insulating switching member made of an insulating material. 
     As shown in  FIGS.  69 - 70   , the control member  115  includes a switching button  116  penetrating through the housing  111  and a trigger unit  127  corresponding to the switching button  116 . The trigger unit  127  is slidably received in the housing  111  and can slide along the plugging direction under the drive of the switching button  116 . An elastic member  1141  is provided at one end of the trigger unit  127  opposite to the switching button  116 , so that the trigger unit  127  can conveniently and quickly drive the switching member  114  switch between in the first position and the second position under the combined action of the switching button  116  and the elastic member  1141 . 
     As shown in  FIG.  71   , the switching member  114  can include a first switching member  1142  and a second switching member  1143  that are arranged in parallel on both sides of the movement direction (i.e., the plugging direction) of the trigger unit  127 . The positive and negative terminals are arranged adjacently in the plug  112 , that is, the positive terminal  1121   a  and the positive terminal  1122   a , the positive terminal  1122   a  and the negative terminal  1121   b , the negative terminal  1121   b  and the negative terminal  1122   b  are all provided with connecting protrusions for electrical connection with each other. The connecting protrusions between the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b  are located on the same straight line, and the connecting protrusions between the positive terminal  1122   a  and the negative terminal  1121   b  are arranged in a staggered manner. 
     As shown in  FIGS.  72 - 73   , the control member  115  in this embodiment can have a first switching position corresponding to the first position and a second switching position corresponding to the second position. When the control member  115  is in the first position, the switching member  114  is separated from the first plug member  1121  and the second plug member  1122 . At this time, the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b  are connected to each other through the connecting protrusions. The connection protrusions between the positive terminal  1122   a  and the negative terminal  1121   b  are separated from each other, so that the first energy unit and the second energy unit are connected in parallel, and further a low voltage (i.e. nV) output is realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  74 - 75   , when the control member  115  is in the second switching position, the switching member  114  is in the second position. At this time, the first switching member  1142  and the second switching member  1143  are respectively driven by the switching button  116  and the trigger unit  127  to move to the position between the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b , in order to separate the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b . At this time, the connecting protrusions between the positive terminal  1122   a  and the negative terminal the terminals  1121   b  are electrically connected to each other under the action of deformation, so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e. 2nV) output is further realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  76 - 77   , an electric energy storage system is further provided in the disclosure. The electric energy storage system also includes a first energy unit and a second energy unit. The main difference is that the power switching device  11  is a switching device that switches between the first position and the second position by pushing and pulling. 
     As shown in  FIGS.  76 - 77   , the power switching device  11  includes a housing  111 , a plug  112  housed in the housing  111 , and an power switching assembly (not labeled) that is adjustable and connected to the plug  112 . The plug  112  includes a first plug member  1121  and a second plug member  1122 , and an output terminal  1123  for realizing electric energy output, and both the first plug member  1121  and the second plug member  1122  have positive terminals ( 1121   a ,  1122   a ) and negative terminals ( 1121   b ,  1122   b ), the output terminal  1123  can include a positive output terminal  1123   a  and a negative output terminal  1123   b.    
     As shown in  FIG.  77   , the first plug member  1121  and the second plug member  1122  of this embodiment are arranged in a form of a positive terminal  1121   a , a negative terminal  1121   b , a positive terminal  1122   a , and a negative terminal  1122   b , and connecting protrusions for electrically connecting to each other are disposed between the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b.    
     As shown in  FIG.  77   , the switching member  114  includes a first switching member  1142 , a second switching member  1143 , and a third switching member  1144 . The first switching member  1142  and the second switching member  1143  are arranged in parallel on both sides of the movement direction (that is, the plugging direction) of the trigger unit  127 . The third switching member  1144  is disposed between the first switching member  1142  and the second switching member  1143 . And in this embodiment, the first switching member  1142  and the second switching member  1143  are made of an insulating material, and the third switching member  1144  is made of a conductive material. 
     As shown in  FIG.  77   , the control member includes a switching button  116  penetrating through the housing  111  and a trigger unit  127  corresponding to the switching button  116 . The trigger unit  127  is slidably accommodated in the housing  111  and can be driven by the switching button  116  to slide in the plugging direction. An elastic member  1141  is provided at one end of the trigger unit  127  opposite to the switching button  116 , so that the trigger unit  127  can conveniently and quickly drive the switching member  114  to switch between the first position and the second position under the combined action of the switching button  116  and the elastic member  1141 . 
     As shown in  FIGS.  76 - 77   , the control member in this embodiment can include a first switching position corresponding to the first position and a second switching position corresponding to the second position. When the control member is in the first position, the switching member  114  is separated from the first plug member  1121  and the second plug member  1122 . At this time, the positive terminal  1121   a  and the positive terminal  1122   a , the negative terminal  1121   b  and the negative terminal  1122   b  are electrically connected to each other through connecting protrusions, so that the first energy unit and the second energy unit are connected in parallel, and a low voltage (i.e., nV) output is further realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIGS.  76 - 77   , when the control member is in the second switching position, the switching member  114  is in the second position. At this time, the first switching member  1142  is plugged between the positive terminal  1121   a  and the positive terminal  1122   a . The switching member  1143  is plugged between the negative terminal  1121   b  and the negative terminal  1122   b  to separate the positive terminal  1121   a  and the positive terminal  1122   a , and the negative terminal  1121   b  and the negative terminal  1122   b . Further, the third switching member  1144  abuts on the negative terminal  1121   b  and the positive terminal  1122   a , and are electrically connected to the negative terminal  1121   b  and the positive terminal  1122   a , so that the first energy unit and the second energy unit are connected in series, and a high-voltage (i.e. 2nV) output is realized through the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123 . 
     As shown in  FIG.  78   , an electric energy storage system is provided in the disclosure. The electric energy storage system can include the same structure as the above-mentioned electric energy storage system. The only difference is that the positive electrodes  12   a ′,  13   a ′ and the negative electrodes  12   b ′,  13   b ′ of the first energy unit and the second energy unit are arranged up and down. 
     As shown in  FIG.  79   , an electric energy storage system is provided in the disclosure. The difference between this electric energy storage system and the above-mentioned electric energy storage system is only: the positive electrodes  12   a ″,  13   a ″ and the negative electrodes  12   b ″,  13   b ″ of the first energy unit and the second energy unit are arranged front and back along the direction of the power switching device  11  and the energy unit, and the negative electrodes  12   b ″,  13   b ″ are parallel to the positive electrode  12   a ″,  13   a″.    
     As shown in  FIGS.  78 - 79   , the arrangement of the plugs  112  in the power switching device  11  can be adjusted according to the arrangement of the positive and negative electrodes of the first energy unit and the second energy unit. When the power switching device  11  is in the first position, the first energy unit and the second energy unit are connected in parallel, and when the power switching device  11  is in the second position, the first energy unit and the second energy unit can be connected in series, that is, the arrangement form of the plugs  112  of the power switching device  11  in can be adjusted according to the actual situation, which is not limited here. 
     An electric tool (not shown) is also provided in the disclosure. The electric tool includes a tool body and a power switching device  11  for electrically connecting the tool body and a power supply device. 
     As shown in  FIG.  1   , in the disclosure, the tool body can include a plug-in portion for connecting the power switching device  11 , the plug-in portion can include two connecting pieces with opposite polarities, and the two connecting pieces with opposite polarities are respectively connected to the positive output terminal  1123   a  and the negative output terminal  1123   b  of the output terminal  1123  of the power switching device  11  with the same polarity to ensure the normal input of a working voltage. 
     In this disclosure, when a rated voltage of the electric tool is nV, the electric tool can be connected to different power supply devices having energy units with an output voltage of n/2V or nV through the power switching device  11 . 
     The electric tool can be connected to a dual-voltage power supply device or a single-voltage power supply device with two energy units with an output voltage of n/2V, and in this embodiment, each energy unit with an output voltage of n/2V can include two output electrodes with opposite polarities. 
     As shown in  FIGS.  1  and  3   , when the electric tool is electrically connected to the dual-voltage power supply device/single-voltage power supply device through the power switching device  11 , the power switching device  11  are respectively electrically connected to the output electrodes of the two energy units with an output voltage of n/2V through the positive terminal  1121   a  and the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  and the negative terminal  1122   b  of the second plug member  1122 . At this time, the switching member  114  can be driven by the switching button  116  to move to the second position, so that the negative terminal  1121   b  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122  are electrically connected through the switching member  114 , so as to control the series connection of two energy units with an output voltage of n/2V, the output voltage of the dual-voltage power supply device or the single-voltage power supply device is nV, which meets the rated voltage of the tool body of the electric tool and ensures the normal operation of the electric tool. 
     The electric tool can be connected to a dual-voltage power supply device or a single-voltage power supply device with two energy units with an output voltage of nV, and each energy unit with an output voltage of nV can include two output electrodes of opposite polarities. 
     As shown in  FIGS.  1  and  3   , when the electric tool is electrically connected to the dual-voltage power supply device/single-voltage power supply device through the power switching device  11 , the switching member  114  can be controlled to move to the first position through the switching button  116 . At this time, the positive terminal  1121   a  of the first plug member  1121  and the positive terminal  1122   a  of the second plug member  1122 , the negative terminal  1121   b  of the first plug member  1121  and the negative terminal  1122   b  of the second plug member  1122  are electrically connected through the switching member  114 ; further to enable the two energy units with an output voltage of nV are connected in parallel, and the output voltage of the dual-voltage power supply device or the single-voltage power supply device is controlled to be nV, which meets the rated voltage of the tool body and ensures the normal operation of the electric tool. 
     In this disclosure, the electric tool can also be connected to a single-voltage power supply device having an energy unit with an output voltage of nV, and the energy unit can include two output electrodes with opposite polarities. 
     As shown in  FIG.  4   , when the electric tool is electrically connected to the single-voltage power supply device through the power switching device  11 , the switching member  114  can be controlled to move to the second position through the switching button  116 . At this time, the positive terminal  1122   a  of the second plug member  1122  is electrically connected to the negative terminal  1121   b  of the first plug member  1121  through the switching member  114 ; further, the power switching device  11  is connected to the two terminals of the first plug member  1121  and the second plug member  1122  arranged side by side and close to each other with opposite polarities, such as the positive terminal  1122   a  of the second plug member  1122  and the negative terminal  1121   b  of the first plug member  1121  in  FIG.  2    are electrically connected to the output electrode of the energy unit with an output voltage of nV, and output a voltage of nV to meet the rated voltage of the tool body, and ensure the normal operation of the electric tool. 
     As shown in  FIG.  80   , an electric tool system  20  is further provided in the disclosure. The electric tool system  20  includes an electric energy storage system and an electric tool  201 . The electric tool  201  is used to perform corresponding work tasks, and the electric energy storage system is used for providing corresponding power to the power tool  201 , which ensures the normal operation of the electric tool system  20 . 
     As shown in  FIG.  80   , the electric tool  201  can include a plug  202  for connecting to an electric energy storage system. The electric tool  201  may be a low-voltage electric tool for accepting a low-voltage input, and it may also be a high-voltage electric tool for accepting a high-voltage input. 
     As shown in  FIG.  80   , the electric energy storage system completes the switching of the output voltage through the power switching device  11  disposed on the electric energy storage system, so that the electric tool system  20  can match a low-voltage electric tool or a high-voltage electric tool, which effectively improves the utility of the tool system  20  in the disclosure. 
     An electric tool system (not shown) further provided in the disclosure, includes an electric energy storage system  10  and an electric tool (not shown), wherein the electric tool is used to perform corresponding work tasks, and the electric energy storage system  10  is used for providing corresponding power to the electric tools to ensure the normal operation of the power tool system. 
     The electric tool can include a plug for connecting the electric energy storage system. The electric tool can be a low-voltage electric tool for receiving a low-voltage input, and it can also be a high-voltage electric tool for receiving a high-voltage input. 
     As shown in  FIG.  81   , the electric energy storage system  10  realizes the output of electric energy through the power switching device  11  provided thereon. In this embodiment, the electric energy storage system  10  can include one single energy unit, and the energy unit is provided with positive and negative electrodes  101   a ,  101   b  corresponding to the first plug member  1121  and the second plug member  1122  of the power switching device  11 . A communication terminal  102  and a signal disposed between the positive electrode  101   a  and the negative electrode  101   b  for signal transmission can ensure the stability of the connection between the power switching device  11  and the energy unit while ensuring the stability of the signal transmission of the power tool system, so that the power tool system can matches the power tool of the plug matched with the output end (not shown) of the power switching device  11 . 
     As shown in  FIG.  81   , in the process of describing the structure of the electric tool, the electric tool system, and the electric tool system  20  in the disclosure, the power switching device  11  includes both the aforementioned power switching device and all power switching devices which do not depart from the spirit and scope of the technical solution of the disclosure, that is, in the process of describing the structure of the power tool and the power tool system  20  in the disclosure, for the convenience of description, only the power switching device  11  is taken as an example for illustration, but this should not be the limit. 
     In summary, the power switching device in the disclosure is provided with a switching member that can be switched between the first position and the second position and a plug electrically connected to the switching member, and by adjusting the coupling form of different plugs, the electric energy storage system with the power switching device can realize the output of two different voltages. At the same time, the electric tool with the power switching device can be matched with a variety of power supply devices with different output voltages or with a single voltage output, which effectively increases the applicable scope of the electric energy storage system/electric tool/electric tool system with the power switching device, and the cost is reduced. 
     The above description is only a preferred embodiment of this application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the disclosure involved in this application is not limited to a technical solution formed by a specific combination of the above technical features. Meanwhile, it should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept, for example, the above-mentioned features and the technical features with similar functions invented in this application (but not limited to) are mutually replaced to form a technical solution. 
     Except for the technical features described in the specification, the remaining technical features are known to those skilled in the art. In order to highlight the innovative features in the disclosure, the rest of the technical features will not be repeated here.