Patent Publication Number: US-2023163437-A1

Title: Electrolyte injection device

Description:
RELATED APPLICATION 
     The application claims the priority of Chinese patent application No. 202122113571.4, filed on Sep. 2, 2021, titled “electrolyte injection device”, the entire contents of which are hereby incorporated by reference. 
     TECHNICAL FILED 
     The application relates to the technical field of electrolyte injection equipment for battery preparation, in particular to an electrolyte injection device. 
     BACKGROUND 
     The inside of a battery case needs to be vacuumized before electrolyte injection. Traditional electrolyte injection equipment is provided with an electrolyte injection block, the electrolyte injection block is provided with an electrolyte injection channel, an air extraction channel and an outlet communicating with both the electrolyte injection channel and the air extraction channel, and the outlet is used for communicating with the inside of the battery case. 
     The electrolyte injection block needs to be used repeatedly. Since the electrolyte injection block only has one outlet, output ends of the electrolyte injection channel and the air extraction channel are connected to each other, and after air extraction, the inside of the air extraction channel and the inside of the battery case are both under negative pressure, an electrolyte input via the electrolyte injection channel enters the air extraction channel easily, which will affect the use of an air extraction device. 
     SUMMARY 
     In view of the problem that an electrolyte enters an air extraction channel of an electrolyte injection block easily, it is necessary to provide an electrolyte injection device which prevents an electrolyte from affecting an air extraction device. 
     To solve the above technical problems, the technical scheme adopted by this application is as follows. An electrolyte injection device comprises: 
     a support plate, bearing a battery; 
     a first electrolyte injection cup, connected to the support plate, and having a communication port communicating with an electrolyte injection port of the battery, and an electrolyte inlet and an air extraction port communicating with the communication port; 
     a second electrolyte injection cup, for storing an electrolyte and arranged above the first electrolyte injection cup; 
     an air extraction assembly having an air extraction channel with an end for communicating with an air extraction device; and 
     an electrolyte injection assembly, connected to the air extraction assembly, arranged between the first electrolyte injection cup and the second electrolyte injection cup, and having an electrolyte injection channel, the electrolyte injection assembly and the second electrolyte injection cup being capable of moving close to and away from each other, and the second electrolyte injection cup communicating with an end of the electrolyte injection channel when the second electrolyte injection cup is close to and abuts against the electrolyte injection assembly; 
     wherein the air extraction assembly and the electrolyte injection assembly are capable of synchronously moving close to and away from the first electrolyte injection cup, and when the air extraction assembly and the electrolyte injection assembly are synchronously close to and abut against the first electrolyte injection cup, another end, away from the air extraction device, of the air extraction channel communicates with the air extraction port, and another end, away from the second electrolyte injection cup, of the electrolyte injection channel communicates with the electrolyte inlet. 
     By means of the above-mentioned electrolyte injection device, the battery is placed on the support plate first, then the air extraction assembly and the electrolyte injection assembly are moved close to and abut against the first electrolyte injection cup, and next the second electrolyte injection cup is made to abut against the electrolyte injection assembly, so that the air extraction device communicates with the electrolyte injection port of the battery through the air extraction channel, the air extraction port and the communication port, and the second electrolyte injection cup communicates with the electrolyte injection port of the battery through the electrolyte injection channel, the electrolyte inlet and the communication port. At the beginning, an electrolyte outlet of the second electrolyte injection cup is in a closed state, and the air extraction device operates to vacuumize the inside of the battery, the air extraction channel and the electrolyte injection channel. After vacuumizing, the air extraction device is closed, and then the electrolyte outlet of the second electrolyte injection cup is opened, so that the electrolyte in the second electrolyte injection cup flows into the battery through the electrolyte injection channel. As the air extraction device and the second electrolyte injection cup communicate with the battery on the support plate through the air extraction assembly and the electrolyte injection assembly respectively, and the air extraction assembly and the electrolyte injection assembly are separated from the first electrolyte injection cup, the second electrolyte injection cup and the air extraction device, the electrolyte can be effectively prevented from entering the air extraction device and will not affect the use of the air extraction device. 
     In one embodiment, the first electrolyte injection cup further comprises a transit chamber communicating with the communication port, the electrolyte inlet and the air extraction port, and the communication port is provided in a bottom wall of the transit chamber; and 
     the electrolyte injection device further comprises a stop block connected to the first electrolyte injection cup and located in the transit chamber, a diversion channel is formed by enclosing of the stop block and a top wall or side wall of the transit chamber, the diversion channel communicates with the air extraction port, and an opening of the diversion channel faces the side wall or top wall of the transit chamber. 
     In one embodiment, the electrolyte injection device further comprises a first mating part and a second mating part, the first mating part is connected to the support plate, the second mating part is connected to the first electrolyte injection cup, and the first mating part and the second mating part are connected detachably. 
     In one embodiment, the electrolyte injection device further comprises a bearing plate which is detachably connected to the support plate, and the first electrolyte injection cup is mounted on the bearing plate. 
     In one embodiment, the air extraction assembly comprises an air extraction nozzle and an air extraction joint connected to each other, a channel inside the air extraction nozzle communicates with a channel inside the air extraction joint to form the air extraction channel, the air extraction joint is for communicating with the air extraction device, and when the air extraction assembly is close to and abuts against the first electrolyte injection cup, the air extraction nozzle communicates with the air extraction port. 
     In one embodiment, the electrolyte injection assembly comprises an electrolyte injection nozzle and an electrolyte injection joint connected to each other, a channel inside the electrolyte injection nozzle communicates with a channel inside the electrolyte injection joint to form the electrolyte injection channel, when the electrolyte injection assembly is close to and abuts against the first electrolyte injection cup, the electrolyte injection nozzle communicates with the electrolyte inlet, and when the second electrolyte injection cup is close to and abuts against the electrolyte injection assembly, the second electrolyte injection cup communicates with the electrolyte injection joint. 
     In one embodiment, the electrolyte injection device further comprises a driving assembly; 
     the air extraction assembly is arranged above the first electrolyte injection cup, and the driving assembly is in driving connection with the support plate to drive the support plate and the first electrolyte injection cup to move upward and downward to be close to and away from the air extraction assembly and the electrolyte injection assembly; 
     or, the driving assembly is in driving connection with the air extraction assembly and the electrolyte injection assembly to drive the air extraction assembly and the electrolyte injection assembly to be close to and away from the first electrolyte injection cup. 
     In one embodiment, the electrolyte injection device further comprises an elastic assembly, the driving assembly is in driving connection with the elastic assembly, both the air extraction assembly and the electrolyte injection assembly are connected to the elastic assembly, and when the air extraction assembly and the electrolyte injection assembly are close to and abut against the first electrolyte injection cup, the elastic assembly is for providing an elastic force to keep the air extraction assembly and the electrolyte injection assembly away from the first electrolyte injection cup. 
     In one embodiment, the air extraction assembly is arranged above the first electrolyte injection cup, the elastic assembly comprises a fixed piece, a guide piece and an elastic piece, the driving assembly is in driving connection with the fixed piece, the guide piece is connected to the fixed piece in a reciprocating manner in a vertical direction, the elastic piece is connected between the fixed piece and the guide piece, and both the air extraction assembly and the electrolyte injection assembly are connected to the guide piece. 
     In one embodiment, the support plate is for bearing a plurality of batteries, and the electrolyte injection device comprises a plurality of first electrolyte injection cups, a plurality of groups of air extraction assemblies, a plurality of second electrolyte injection cups and a plurality of groups of the electrolyte injection assemblies; 
     the communication port of each first electrolyte injection cup is for communicating with the electrolyte injection port of the corresponding battery; 
     an end of each of the air extraction channels communicates with the air extraction device, an end, away from the air extraction device, of the air extraction channel of any air extraction assembly abutting against the first electrolyte injection cup communicates with the corresponding air extraction port, and an end of the electrolyte injection channel of any electrolyte injection assembly abutting against the first electrolyte injection cup communicates with the electrolyte inlet; and 
     each of the second electrolyte injection cups is capable of abutting against the corresponding electrolyte injection assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a structural diagram of a conventional battery; 
         FIG.  2    is a structural diagram of an electrolyte injection device provided in an embodiment of the application; 
         FIG.  3    is a diagram of the matching relationship between a bearing assembly of the electrolyte injection device shown in  FIG.  2    and mechanisms such as an air extraction assembly and an electrolyte injection assembly; 
         FIG.  4    is a diagram of the matching relationship between an electrolyte injection cup of the electrolyte injection device shown in  FIG.  2    and mechanisms such as an air extraction assembly and an electrolyte injection assembly; and 
         FIG.  5    is a structural diagram of a bearing assembly of the electrolyte injection device shown in  FIG.  2   . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The application provides an electrolyte injection device. In order to make the purpose, technical scheme and effect of the application clearer and more definite, the application will be further explained in detail with reference to the attached drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the application, but are not used to limit the application. 
     As shown in  FIGS.  2 - 4   , an electrolyte injection device provided in an embodiment of the application is used for vacuumizing the inside of a battery  200  through an electrolyte injection port  201  of the battery  200  and injecting an electrolyte into the battery  200 . The electrolyte injection device comprises a support plate  11 , a first electrolyte injection cup  12 , an air extraction assembly  20 , an electrolyte injection assembly  30  and a second electrolyte injection cup  40 . 
     The support plate  11  is used for supporting the battery  200 . The first electrolyte injection cup  12  is connected to the support plate  11 , and the first electrolyte injection cup  12  is provided with a communication port  121  communicating with the electrolyte injection port  201  of the battery  200 , and an electrolyte inlet  122  and an air extraction port  123  communicating with the communication port  121 . The second electrolyte injection cups  40  are arranged above the first electrolyte injection cups  12  and used for storing an electrolyte. 
     The air extraction assembly  20  is provided with an air extraction channel  21  with an end used for communicating with the air extraction device, and the electrolyte injection assembly  30  is connected to the air extraction assembly  20  and arranged between the first electrolyte injection cup  12  and the second electrolyte injection cup  40  to move close to and away from the first electrolyte injection cup  12  synchronously with the air extraction assembly  20 . The electrolyte injection assembly  30  is provided with an electrolyte injection channel  31 . 
     When the air extraction assembly  20  and the electrolyte injection assembly  30  synchronously are close to and abut against the first electrolyte injection cup  12 , another end, away from the air extraction device, of the air extraction channel  21  communicates with the air extraction port  123 , and an end of the electrolyte injection channel  31  communicates with the electrolyte inlet  122 . 
     The electrolyte injection assembly  30  and the second electrolyte injection cup  40  can move close to and away from each other. When the electrolyte injection assembly  30  is close to and abuts against the first electrolyte injection cup  12 , an end of the electrolyte injection channel  31  communicates with the electrolyte inlet  122 . And when the second electrolyte injection cup  40  is close to and abuts against the electrolyte injection assembly  30 , the second electrolyte injection cup  40  communicates with another end, away from the electrolyte inlet  122 , of the electrolyte injection channel  31 . 
     By means of the above-mentioned electrolyte injection device, the battery  200  is placed on the support plate  11  firstly, then the air extraction assembly  20  and the electrolyte injection assembly  30  are moved close to and abut against the first electrolyte injection cup  12 , and next the second electrolyte injection cup  40  is made to abut against the electrolyte injection assembly  30 , so that the air extraction device communicates with the electrolyte injection port  201  of the battery  200  through the air extraction channel  21 , the air extraction port  123  and the communication port  121 , and the second electrolyte injection cup  40  communicates with the electrolyte injection port  201  of the battery  200  through the electrolyte injection channel  31 , the electrolyte inlet  122  and the communication port  121 . At the beginning, an electrolyte outlet of the second electrolyte injection cup  40  is in a closed state, and the air extraction device operates to vacuumize the inside of the battery  200 , the air extraction channel  21  and the electrolyte injection channel  31 . After vacuumizing, the air extraction device is closed, and then the electrolyte outlet of the second electrolyte injection cup  40  is opened, so that the electrolyte in the second electrolyte injection cup  40  flows into the battery  200  through the electrolyte injection channel  31 . As the air extraction device and the second electrolyte injection cup  40  communicate with the battery  200  on the support plate  11  through the air extraction assembly  20  and the electrolyte injection assembly  30  respectively, and the air extraction assembly  20  and the electrolyte injection assembly  30  are separated from the first electrolyte injection cup  12 , the second electrolyte injection cup  40  and the air extraction device, the electrolyte can be effectively prevented from entering the air extraction device and will not affect the use of the air extraction device. 
     It should be noted that any two of the electrolyte injection assembly  30 , the second electrolyte injection cup  40  and the first electrolyte injection cup  12  can move close to and away from each other in the vertical direction, that is, the electrolyte injection assembly  30  and the second electrolyte injection cup  40  can move close to and away from each other, the electrolyte injection assembly  30  and the first electrolyte injection cup  12  can move close to and away from each other, and the first electrolyte injection cup  12  and the second electrolyte injection cup  40  can move close to and away from each other. The electrolyte injection assembly  30  is located between the first electrolyte injection cup  12  and the second electrolyte injection cup  40 , so both the first electrolyte injection cup  12  and the second electrolyte injection cup  40  abut against the electrolyte injection assembly  30 . 
     It can be understood that the electrolyte injection assembly  30 , the second electrolyte injection cup  40  and the first electrolyte injection cup  12  can all move upward and downward, or when one of the electrolyte injection assembly  30 , the second electrolyte injection cup  40  and the first electrolyte injection cup  12  is fixed, the other two of which can move upward and downward. 
     Referring to  FIGS.  2 ,  3  and  5   , in some embodiments, a bracket is formed on the support plate  11 , and the bracket is used for bearing the battery  200  and positioning the battery  200  to prevent the battery  200  from shaking during electrolyte injection. 
     In some embodiments, the first electrolyte injection cup  12  further has a transit chamber  124 , the communication port  121 , the electrolyte inlet  122  and the air extraction port  123  all communicate with the transit chamber  124 , and the communication port  121  is provided in a bottom wall of the transit chamber  124 . In this way, during vacuumizing and electrolyte injection, both gas and the electrolyte will pass through the transit chamber  124  and be buffered by the transit chamber  124 , so that the electrolyte can be prevented from entering the air extraction port  123 . 
     In addition, it should be noted that the first electrolyte injection cup  12  is separated from the air extraction assembly  20 , the electrolyte injection assembly  30  and the second electrolyte injection cup  40 . Therefore, after electrolyte injection of the battery  200  on the support plate  11 , some of the electrolyte in the transit chamber  124  may not flow into the battery  200 . At this point, the support plate  11  and the first electrolyte injection cup  12  can be moved away from the bottom of the electrolyte injection assembly  30  and allowed to stand for a period of time, so that the electrolyte can completely enter the battery  200  and the internal pressure and external pressure of the battery  200  can be equal. 
     Further, the electrolyte inlet  122  and the air extraction port  123  are both provided in a top wall of the transit chamber  124  to communicate with the electrolyte injection assembly  30  and the air extraction assembly  20  located above the first electrolyte injection cup  12 . 
     In practice, the bottom wall of the transit chamber  124  is funnel-shaped, and the communication port  121  is located at the lowest position of the bottom wall of the transit chamber  124 , so as to prevent the electrolyte from accumulating on the bottom wall of the transit chamber  124 . 
     Specifically, the side wall and the bottom wall of the transit chamber  124  are connected by an arc surface to avoid the accumulation of the electrolyte. 
     In some embodiments, the electrolyte injection device further comprises a stop block  13  connected to the first electrolyte injection cup  12  and located in the transit chamber  124 , a diversion channel is formed by enclosing of the stop block  13  and the top wall or side wall of the transit chamber  124 , the diversion channel communicates with the air extraction port  123 , and an opening of the diversion channel faces the side wall or top wall of the transit chamber  124  to prevent the electrolyte dripping on the bottom wall of the transit chamber  124  from splashing into the air extraction port  123 . 
     It can be understood that the function of the stop block  13  is to prevent the air extraction port  123  from directly facing the bottom wall of the transit chamber  124 , so as to prevent the electrolyte dripping on the bottom wall from splashing into the air extraction port  123 . 
     In addition, it should be noted that when the stop block  13  is connected to the side wall of the transit chamber  124 , the opening of the diversion channel faces upwards, and the splashing electrolyte can enter the diversion channel from the opening of the diversion channel. In order to prevent the splashing electrolyte from accumulating in the diversion channel, a bottom of the diversion channel is provided with a drain hole for discharging the accumulated electrolyte. 
     Further, the stop block  13  is connected to the top wall of the transit chamber  124  and located between the air extraction port  123  and the electrolyte inlet  122 . The stop block  13  has an inclined surface, the diversion channel is formed by enclosing of the inclined surface and the top wall, and both the air extraction port  123  and the electrolyte inlet  122  communicate with the diversion channel. 
     In practice, the stop block  13  is provided with a through hole  131  which runs through stop block  13  in the vertical direction, and the through hole  131  corresponds to the electrolyte inlet  122 , so as to facilitate electrolyte injection and prevent the electrolyte from hitting the inclined surface of the stop block  13  and splashing in the transit chamber  124 . 
     In some embodiments, the electrolyte injection device further comprises a first mating part  141  and a second mating part  142 , the first mating part  141  is connected to the support plate  11 , the second mating part  142  is connected to the first electrolyte injection cup  12 , and the first mating part  141  and the second mating part  142  are detachably connected, so that the first electrolyte injection cup  12  and the support plate  11  are locked and fixed. 
     In practice, the first mating part  141  is a clamping jaw rotatably connected to the support plate  11 , and the second mating part  142  is located on a clamping block fixedly connected to the first electrolyte injection cup  12 . After the first electrolyte injection cup  12  is connected to the support plate  11 , the clamping jaw is rotated to be clamped with the clamping block, so that the first electrolyte injection cup  12  and the support plate  11  are locked and fixed. 
     It can be understood that the first mating part  141  and the second mating part  142  can also be mated in other ways, such as an electromagnet and a metal block, a clamping block and a groove, and a clamping jaw and a lug, etc., which is not limited here, as long as the first electrolyte injection cup  12  and the support plate  11  can be locked and fixed. 
     In some embodiments, the electrolyte injection device further comprises a positioning member  15 , which is arranged on the support plate  11 , and the first electrolyte injection cup  12  is provided with a positioning hole. When the first electrolyte injection cup  12  is mounted on the support plate  11 , the positioning member  15  penetrates through the positioning hole to ensure that the first electrolyte injection cup  12  is accurately mounted on the support plate  11 , thereby ensuring that the communication port  121  of the first electrolyte injection cup  12  communicates with the electrolyte injection port  201  of the battery  200  when the first electrolyte injection cup  12  is mounted on the support plate  11 . 
     In practice, the positioning member  15  is a positioning pin. Of course, in other embodiments, the positioning pin can also be arranged on the first electrolyte injection cup  12 , and the support plate  11  is correspondingly provided with a positioning hole. 
     In some embodiments, the electrolyte injection device further comprises a support assembly, which is arranged on the support plate  11  and used for supporting the first electrolyte injection cup  12  when the first electrolyte injection cup  12  is mounted on the support plate  11 . 
     Further, the support assembly comprises a first support member  161  and a second support member  162 , an end of the first support member  161  is connected to the support plate  11 , and the second support member  162  is fixedly connected to another end, away from the support plate  11 , of the first support member  161 . The first support member  161  provides an elastic force to push the first support member  161  away from the support plate  11 , and the second support member  162  is used to abut against the first electrolyte injection cup  12  when the first electrolyte injection cup  12  is mounted on the support plate  11 . 
     In this way, when the first electrolyte injection cup  12  and the support plate  11  need to be connected, the positioning hole in the first electrolyte injection cup  12  passes through the positioning member  15  on the support plate  11 , and then the first electrolyte injection cup  12  is pressed down against the elastic force of the first support member  161  until the first mating part  141  and the second mating part  142  can be connected together, so as to lock the first electrolyte injection cup  12  with the support plate  11 . To separate the first electrolyte injection cup  12  from the support plate  11 , the first mating part  141  and the second mating part  142  are separated first, so that the first electrolyte injection cup  12  will bounce up under the action of the first support member  161  and the second support member  162 , and then the first electrolyte injection cup  12  can be detached. 
     In practice, the first support member  161  is a spring, and the second support member  162  is a movable block. Both the spring and the movable block are disposed around the positioning pin, which extends in the vertical direction and can also guide the movement of the spring and the movable block. 
     Referring to  FIGS.  3  and  4   , in some embodiments, the air extraction assembly  20  comprises an air extraction nozzle  22  and an air extraction joint  23  which are connected to each other, a channel inside the air extraction nozzle  22  communicates with a channel inside the air extraction joint  23  to form the air extraction channel  21 , the air extraction joint  23  is used for communicating with the air extraction device, and when the air extraction assembly  20  is close to and abuts against the first electrolyte injection cup  12 , the air extraction nozzle  22  communicates with the air extraction port  123 . 
     Further, the air extraction assembly  20  further comprises an air extraction block  24  with a first communication channel, the air extraction nozzle  22  and the air extraction joint  23  are respectively connected to two opposite ends of the air extraction block  24 , and the channel inside the air extraction nozzle  22  and the channel inside the air extraction joint  23  respectively communicate with two opposite ends of the first communication channel of the air extraction block  24 , so that the channel inside the air extraction nozzle  22 , the first communication channel and the channel inside the air extraction joint  23  all communicate to form the air extraction channel  21 . 
     In some embodiments, the electrolyte injection assembly  30  comprises an electrolyte injection nozzle  32  and an electrolyte injection joint  33  which are connected to each other, a channel inside the electrolyte injection nozzle  32  communicates with a channel inside the electrolyte injection joint  33  to form the electrolyte injection channel  31 , when the electrolyte injection assembly  30  is close to and abuts against the first electrolyte injection cup  12 , the electrolyte injection nozzle  32  communicates with the electrolyte inlet  122 , and when the second electrolyte injection cup  40  is close to and abuts against the electrolyte injection assembly  30 , the second electrolyte injection cup  40  communicates with the electrolyte injection joint  33 . 
     Further, the electrolyte injection assembly  30  comprises an electrolyte injection block  34  with a second communication channel, the electrolyte injection nozzle  32  and the electrolyte injection joint  33  are connected to two opposite ends of the electrolyte injection block  34  respectively, and the channel inside the electrolyte injection nozzle  32  and the channel inside the electrolyte injection joint  33  respectively communicate with two opposite ends of the second communication channel of the electrolyte injection block  34 , so that the channel inside the electrolyte injection nozzle  32 , the second communication channel and the channel inside the electrolyte injection joint  33  communicate with one another to form the electrolyte injection channel  31 . 
     It should be noted that both the air extraction nozzle  22  and the electrolyte injection nozzle  32  abut against the first electrolyte injection cup  12 , and when the air extraction nozzle  22  and the electrolyte injection nozzle  32  abut against the first electrolyte injection cup  12 , the air extraction nozzle  22  and the electrolyte injection nozzle  32  are sealed from the first electrolyte injection cup  12  to avoid gas and electrolyte leakage. 
     In some embodiments, the electrolyte injection nozzle  32  has an abutting part and a tip connected to each other, the channel inside the electrolyte injection nozzle  32  passes through the abutting part and the tip, the abutting part is used for abutting against the first electrolyte injection cup  12  to ensure the tightness, and the tip is used for passing through the electrolyte inlet  122  and extending into the transit chamber  124  to directly input the electrolyte into the transit chamber  124 . 
     Referring to  FIG.  2   , in some embodiments, the electrolyte injection device further comprises a driving assembly  50  which is in driving connection with the air extraction assembly  20  and the electrolyte injection assembly  30  to drive the air extraction assembly  20  and the electrolyte injection assembly  30  to move close to and away from the support plate  11  and the first electrolyte injection cup  12 . 
     It should be noted that when the support plate  11  is fixed under the electrolyte injection assembly  30 , the second electrolyte injection cup  40  can also move upward and downward, and the second electrolyte injection cup  40  can be driven to move upward and downward by the driving assembly  50 , or a driving mechanism can be additionally arranged to drive the second electrolyte injection cup  40  to move upward and downward, which is not limited here. 
     It should be further noted that the support plate  11  being fixed under the electrolyte injection assembly  30  means that the battery  200  on the support plate  11  is fixed under the electrolyte injection assembly  30  when vacuumizing and electrolyte injection are required. After electrolyte injection, the support plate  11  and the first electrolyte injection cup  12  can be moved away from under the electrolyte injection assembly  30 . That is, the electrolyte injection device has a frame, on which the electrolyte injection assembly  30  and the second electrolyte injection cup  40  are arranged and can move upward and downward. The frame has an installation position under the electrolyte injection assembly  30 , and the support plate  11  is detachably mounted at the installation position. 
     In other embodiments, the driving assembly  50  is in driving connection with the support plate  11  to drive the support plate  11  and the first electrolyte injection cup  12  to move upward and downward, so as to be close to and away from the air extraction assembly  20  and the electrolyte injection assembly  30 . Therefore, the air extraction assembly  20  is arranged above the support plate  11  in this embodiment. 
     It should be noted that the driving assemblies  50  in the two embodiments may be identical in structure. In the following description, it is assumed that the driving assembly  50  is in driving connection with the air extraction assembly  20  and the electrolyte injection assembly  30 , and the air extraction assembly  20  is located above the support plate  11 . 
     In some embodiments, the driving assembly  50  comprises a driving member  51  and a transmission unit, and the driving member  51  drives the air extraction assembly  20  and the electrolyte injection assembly  30  to move upward and downward through the transmission unit. Of course, the air extraction assembly  20  and the electrolyte injection assembly  30  may also be driven by separate driving members  51 , so that the air extraction assembly  20  can move horizontally and the electrolyte injection assembly  30  can move vertically. 
     In practice, the driving member  51  is a motor, and the transmission unit comprises a transmission belt  52 , a screw  53  and a transmission nut  54 . The transmission belt  52  is connected to the driving member  51  and the screw  53 , and the transmission nut  54  is in screw-thread fit with the screw  53 , and is fixedly connected to the air extraction assembly  20  and the electrolyte injection assembly  30 . 
     Referring to  FIGS.  2  and  3   , in some embodiments, the electrolyte injection device further comprises an elastic assembly  60 , the driving assembly  50  is in driving connection with the elastic assembly  60 , both the air extraction assembly  20  and the electrolyte injection assembly  30  are connected to the elastic assembly  60 , and when the air extraction assembly  20  and the electrolyte injection assembly  30  are close to and abut against the first electrolyte injection cup  12 , the elastic assembly  60  is used for providing an elastic force to keep the air extraction assembly  20  and the electrolyte injection assembly  30  away from the first electrolyte injection cup  12 . 
     The elastic assembly  60  can provide the elastic force to keep the air extraction assembly  20  and the electrolyte injection assembly  30  away from the support plate  11 , which means that when the air extraction assembly  20  and the electrolyte injection assembly  30  abut against the first electrolyte injection cup  12 , the air extraction assembly  20  and the electrolyte injection assembly  30  are not in rigid contact with the first electrolyte injection cup  12 , thus preventing one or more of the air extraction assembly  20 , the electrolyte injection assembly  30  and the first electrolyte injection cup  12  from being damaged. 
     Further, the elastic assembly  60  comprises a fixed piece  61 , a guide piece  62  and an elastic piece  63 , the driving assembly  50  is in driving connection with the fixed piece  61 , the guide piece  62  is connected to the fixed piece  61  in a reciprocating manner in a vertical direction, the elastic piece  63  is connected between the fixed piece  61  and the guide piece  62 , and both the air extraction assembly  20  and the electrolyte injection assembly  30  are connected to the guide piece  62 . 
     In practice, the elastic assembly  60  further comprises a connecting block  64  which is fixedly connected to an end of the guide piece  62 , the elastic piece  63  is connected between the fixed piece  61  and the connecting block  64 , and the air extraction assembly  20  and the electrolyte injection assembly  30  are both fixedly connected to the connecting block  64 . 
     Specifically, the fixed piece  61  is a linear bearing, the guide piece  62  is a vertically extending guide column, and the elastic piece  63  is a spring which is disposed around the guide column. 
     In some embodiments, the electrolyte injection device comprises a mounting frame  71  and a mounting plate  72 , the driving assembly  50  is mounted on the mounting frame  71 , the mounting plate  72  is connected to the mounting frame  71  and can move upward and downward, and both the air extraction assembly  20  and the electrolyte injection assembly  30  are connected to the mounting plate  72 . 
     Further, the elastic assembly  60  is connected to the mounting plate  72 , and the air extraction assembly  20  and the electrolyte injection assembly  30  are connected to the elastic assembly  60 . 
     In some embodiments, the support plate  11  is used for bearing a plurality of batteries  200 , the electrolyte injection device comprises a plurality of first electrolyte injection cups  12 , and the communication port  121  of each first electrolyte injection cup  12  is used for communicating with the electrolyte injection port  201  of a corresponding battery. 
     Further, the electrolyte injection device comprises a plurality of groups of air extraction assemblies  20  and a plurality of groups of electrolyte injection assemblies  30 , an end of each air extraction channel  21  communicates with the air extraction device, an end, away from the air extraction device, of the air extraction channel  21  of any air extraction assembly  20  abutting against the first electrolyte injection cup  12  communicates with the corresponding air extraction port  123 , and an end of the electrolyte injection channel  31  of any electrolyte injection assembly  30  abutting against the first electrolyte injection cup  12  communicates with the electrolyte inlet  122 . 
     In practice, the electrolyte injection device further comprises a plurality of second electrolyte injection cups  40 , each second electrolyte injection cup  40  can abut against a corresponding electrolyte injection assembly  30 , so that the second electrolyte injection cup  40  communicates with the electrolyte injection channel  31  of the corresponding electrolyte injection assembly  30 , and thus the second electrolyte injection cup  40  communicates with the electrolyte injection port  201  of the corresponding battery  200 . 
     In some embodiments, the electrolyte injection device further comprises a bearing plate  17 , the support plate  11  is provided with a plurality of brackets, and a plurality of first electrolyte injection cups  12  are mounted on the bearing plate  17  which is detachably connected to the support plate  11 . When the bearing plate  17  is connected to the support plate  11 , the plurality of first electrolyte injection cups  12  are in one-to-one correspondence with the batteries  200  in the plurality of brackets, that is, the communication port  121  of each first electrolyte injection cup  12  communicates with the electrolyte injection port  201  of a corresponding battery  200 . 
     In addition, it can be understood that the first mating part  141  is connected to the support plate  11 , the second mating part  142  is connected to the bearing plate  17 , and the positioning hole is provided in the bearing plate  17 . 
     Further, the bearing plate  17  is provided with a connecting hole for the first electrolyte injection cup  12  to pass through, and a bottom of the first electrolyte injection cup  12  passes through the connecting hole, so that the communication port  121  in the bottom of the first electrolyte injection cup  12  communicates with the electrolyte injection port  201  in the battery  200 . 
     In some embodiments, a plurality of groups of air extraction assemblies  20  and a plurality of groups of electrolyte injection assemblies  30  are mounted on the mounting plate  72  to move upward and downward synchronously with the mounting plate  72 , thereby simultaneously vacuumizing and injecting the electrolyte into a plurality of batteries  200 . 
     Further, a plurality of groups of elastic assemblies  60  are provided and all connected to the mounting plate  72 , and each group of air extraction assemblies  20  and each group of electrolyte injection assemblies  30  are connected to a corresponding group or two groups of elastic assemblies  60 . 
     In practice, the driving member  51  is mounted on the mounting frame  71 , the screw  53  is rotatably connected to the mounting frame  71  around a vertical axis, the driving nut  54  is fixedly connected to the mounting plate  72 , fixed blocks of each group of elastic assemblies  60  are fixedly connected to the mounting plate  72 , and each group of air extraction assemblies  20  and each group of electrolyte injection assemblies  30  are fixedly connected to a corresponding connecting block  64 . 
     In some embodiments, two mounting frames  71  are provided and arranged in the horizontal direction in a spaced manner, the support plate  11  is positioned between the two mounting frames  71 , and two opposite ends of the mounting plate  72  are respectively slidably arranged on the two mounting frames  71 . 
     Further, two groups of driving assemblies  50  are provided, which are respectively mounted on the two mounting frames  71  and are in driving connection with the opposite ends of the mounting plate  72  respectively to drive the mounting plate  72  to move upward and downward stably. 
     It may be understood that for those of ordinary skill in the art, equivalent substitutions or changes may be made according to the technical solution and inventive concept of the application, and all these changes or substitutions should belong to the protection scope of the appended claims of the application.