Patent Publication Number: US-2023136854-A1

Title: Connection member and rechargeable battery

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 16/962,527, filed on Jul. 16, 2020, which is National Stage of International Application No. PCT/CN2018/080679, filed on Mar. 27, 2018, which claims priority to Chinese Patent Application No. 201820067943.X entitled “CONNECTION MEMBER AND RECHARGEABLE BATTERY” and filed on Jan. 16, 2018, the entire contents of all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This application relates to the technical field of batteries, and in particular to a connection member and a rechargeable battery. 
     BACKGROUND 
     With development of science and technology, increasingly high requirements are imposed on rechargeable batteries. Lithium-ion batteries are used as an example. With advantages of high energy density, high power density, a long cycle life, and a long endurance time, the lithium-ion batteries are widely used in portable electronic devices such as mobile phones, digital cameras, and laptop computers, and are growing in popularity with electric transport such as electric vehicles and electric bicycles, and large and medium electric devices such as energy storage facilities, becoming an important technical means to resolve global problems such as energy crisis and environmental pollution. Electric vehicles and other devices that need to use rechargeable batteries impose higher requirements on energy density and safety performance of the rechargeable batteries. 
     In a prior-art square rechargeable battery, a tab of a battery core is connected to a connection member. A first connecting plate, connected to the tab, of the connection member is typically parallel to a longitudinal direction of the battery core. With growing demand on large-current batteries in the market, to meet a requirement of protecting against temperature rise resulting from battery overcurrent, a sufficient welding area needs to be provided between the first connecting plate and the tab, and the battery core needs to be large enough in a longitudinal direction, thereby occupying more space. This results in low space utilization and low energy density of the battery core. 
     SUMMARY 
     An objective of this application is to provide a connection member and a rechargeable battery, aiming to improve accuracy of a bending position of the connection member, so as to avoid an adverse effect on a size of the connection member being bent. 
     A first aspect of this application provides a connection member of a rechargeable battery, including a guide plate and a first connecting plate integrally formed on the guide plate, the first connecting plate is disposed in a bendable manner relative to the guide plate, and at least one indentation is present between the first connecting plate and the guide plate. 
     In some embodiments, the connection member includes the at least one indentation provided on a side, of the connection member, to which pressure is applied when the first connecting plate is bent relative to the guide plate. 
     In some embodiments, all the indentations of the connection member are provided on the side, of the connection member, to which pressure is applied when the first connecting plate is bent relative to the guide plate. 
     In some embodiments, the guide plate includes a main plate body and a flanged portion, where the flanged portion is arranged at a side edge of the main plate body in a width direction, the first connecting plate is connected to the guide plate through the flanged portion, and a distance between the at least one indentation and the main plate body is 1 to 3 times a thickness of the main plate body. 
     In some embodiments, a cross-sectional shape of the at least one indentation is one of a curve, a polygonal line and a combination of a curve and a straight line. 
     In some embodiments, an opening of the at least one indentation is larger than a bottom of the at least one indentation before the first connecting plate is bent relative to the guide plate. 
     In some embodiments, a depth of the at least one indentation is ¼ to ⅓ of a minimum plate thickness at a position of the at least one indentation when the at least one indentation is not provided. 
     In some embodiments, the at least one indentation is provided continuously along a full or partial length of the bending position between the first connecting plate and the guide plate; or the at least one indentation includes a plurality of indentation segments provided intermittently along the full or partial length of the bending position between the first connecting plate and the guide plate. 
     In some embodiments, ends of a bending position between the first connecting plate and the guide plate include a first root and a second root that are respectively arranged at opposite ends of the bending position, the connection member includes a first groove arranged at the first root and disposed on the first connecting plate and the guide plate, and the first groove is recessed downward from an upper edge of the bending position. 
     In some embodiments, the connection member further includes a second groove arranged at the second root and disposed on the first connecting plate and the guide plate, and the second groove is recessed upward from a lower edge of the bending position. 
     In some embodiments, a thickness of the first connecting plate is set to be smaller than a thickness of the guide plate. 
     In some embodiments, a portion, of the guide plate, connected to the first connecting plate becomes gradually thinner in the direction from the guide plate to the first connecting plate. 
     A second aspect of this application provides a rechargeable battery, including a battery core and the connection member according to any one of the first aspect of this application, where a first connecting plate is connected to a tab of the battery core. 
     In some embodiments, the tab extends from a side of a core body in a width direction; the guide plate extends along the width direction, and the first connecting plate extends to an outer side of the guide plate along the width direction, at least a portion of the guide plate protrudes, relative to the first connecting plate, towards the body of the battery core to form a protrusion, and the protrusion abuts against the battery core. 
     In some embodiments, the rechargeable battery further includes a gasket that is fastened to the first connecting plate and the tab, and the tab is sandwiched between the first connecting plate and the gasket. 
     According to the connection member and the rechargeable battery provided in this application, the at least one indentation is provided to form a thin part at the at least one indentation between the first connecting plate and the guide plate, so that the bending position is more accurate when the first connecting plate is bent relative to the guide plate. This is conducive to an accurate size of the connection member being bent, and is also helpful for the rechargeable battery to successfully assemble the battery core, the connection member, and a housing. Moreover, the at least one indentation makes bending of the first connecting plate more labor-saving, thereby reducing possible damage caused by bending to the battery core and a tab of the battery core. 
     The rechargeable battery of this application includes the foregoing connection member, and therefore has the same advantages as the connection member. 
     Other features and advantages of this application become clear by describing in detail exemplary embodiments of this application with reference to the following accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings described herein are intended to provide a further understanding of this application and constitute a part of this application. The exemplary embodiments of this application and the descriptions thereof are intended to explain this application and do not constitute an inappropriate limitation on this application. In the drawings: 
         FIG.  1    is a schematic structural diagram of a connection member of a rechargeable battery before a first connecting plate is bent relative to a guide plate according to an embodiment of this application; 
         FIG.  2    is a schematic upward view of  FIG.  1   ; 
         FIG.  3    is a schematic enlarged structural diagram of part A of  FIG.  2   ; 
         FIG.  4    is a schematic three-dimensional structural diagram of the connection member of the rechargeable battery shown in  FIG.  1    after a first connecting plate is bent relative to a guide plate; 
         FIG.  5    is a schematic upward view of  FIG.  4   ; 
         FIG.  6    is a schematic enlarged structural diagram of part B of  FIG.  5   ; 
         FIG.  7    is a schematic three-dimensional structural diagram of a rechargeable battery after a housing is disassembled according to an embodiment of this application, where a first connecting plate has been connected to a tab but has not been bent yet; 
         FIG.  8    is a schematic partially-enlarged structural diagram of an upward view of the rechargeable battery according to the embodiment shown in  FIG.  7   ; 
         FIG.  9    is a schematic diagram of a partial structure of an alternative embodiment of the connection member shown in  FIG.  1   ; 
         FIG.  10    is a schematic diagram of a partial structure of another alternative embodiment of the connection member shown in  FIG.  1   ; 
         FIG.  11    is a schematic structural diagram of a battery core of a rechargeable battery according to an embodiment of this application; 
         FIG.  12    is a front view of the battery core shown in  FIG.  11   ; 
         FIG.  13    is an upward view of the battery core shown in  FIG.  11   ; 
         FIG.  14    is a schematic three-dimensional structural diagram of a rechargeable battery after a housing is disassembled according to an embodiment of this application; 
         FIG.  15    is a schematic partially-enlarged structural diagram of an upward view of the rechargeable battery according to the embodiment shown in  FIG.  14   ; 
         FIG.  16    is a schematic structural diagram of a connection member of a rechargeable battery before a first connecting plate is bent relative to a guide plate according to an embodiment of this application; 
         FIG.  17    is a schematic enlarged structural diagram of part C of  FIG.  16   ; 
         FIG.  18    is a schematic three-dimensional structural diagram of a connection member of a rechargeable battery shown in  FIG.  16    after a first connecting plate is bent relative to a guide plate; 
         FIG.  19    is a schematic three-dimensional structural diagram of a rechargeable battery according to an embodiment of this application; 
         FIG.  20    is a schematic three-dimensional structural diagram of a rechargeable battery after a housing is disassembled according to the embodiment shown in  FIG.  19   ; 
         FIG.  21    is a schematic enlarged structural diagram of part D of  FIG.  20   ; 
         FIG.  22    is a schematic cross-sectional structural diagram of an upward view of the rechargeable battery according to the embodiment shown in  FIG.  20   ; and 
         FIG.  23    is a schematic enlarged structural diagram of part E of  FIG.  22   . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following clearly and completely describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are merely some rather than all of the embodiments of this application. The following description of at least one exemplary embodiment is actually merely illustrative and is not intended to constitute any limitation on this application and its application or use. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application. 
     Unless otherwise specified, the relative arrangements, numeric expressions, and values of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the parts shown in the accompanying drawings are not drawn based on actual proportionality. The technologies, methods, and devices known to those of ordinary skill in the relevant fields may not be discussed in detail, but, where appropriate, should be considered as a part of the authorized specification. In all the examples shown and discussed herein, any specific value should be interpreted as merely an example, not as a limitation. Therefore, different values may be used in other examples of exemplary embodiments. It should be noted that similar reference numerals and letters denote similar terms in the following accompanying drawings, so that once a particular term is defined in one of the accompanying drawings, no further discussion is required in the subsequent accompanying drawings. 
     In the description of this application, it should be understood that the use of the terms such as “first” and “second” for limiting parts is merely intended to facilitate distinguishing between corresponding parts. Unless otherwise stated, the foregoing terms have no special meaning, and therefore cannot be construed as a limitation on the protection scope of this application. 
     In the description of this application, it should be understood that the orientation or position relationships indicated by the orientation words such as “front, back, up, down, left, right”, “transverse, lengthwise, vertical, horizontal”, and “top, bottom” are usually based on the orientation or position relationships shown in the accompanying drawings, and are merely intended to facilitate the description of this application and make the description easy. In absence of opposite description, these orientation words do not indicate and imply that the corresponding apparatus or element must have a given orientation or be constructed and operated in a given orientation, and therefore should not be construed as a limitation on the protection scope of this application. The orientation words “inside, outside” refer to the inner side and outer side of a profile of each part. 
     To increase space utilization of the battery core, the first connecting plate is typically bent. During implementation of this application, designers found that, in a process of bending the first connecting plate, an inaccurate bending position may affect a size of a bent connection member  35 , which is not helpful for the rechargeable battery to successfully assemble a battery core  100 , the connection member  35 , and a housing. 
     In the description of this application, a “longitudinal direction” is a longitudinal direction of a rechargeable battery and also a longitudinal direction of a battery core, corresponding to a direction X in  FIG.  7    and  FIG.  19   . A “width direction” is a width direction of the rechargeable battery, corresponding to a direction Y in  FIG.  7    and  FIG.  19   . The “width direction” is also a width direction of a connection member and a guide plate of the connection member. A “height direction” is a direction perpendicular to the longitudinal direction and the width direction, corresponding to a direction Z in  FIG.  7    and  FIG.  19   . The “height direction” is a height direction of the rechargeable battery and the battery core, and also a height direction of the connection member and the guide plate of the connection member. 
       FIG.  1    to  FIG.  23    show structures of the rechargeable battery and parts thereof according to the embodiments of this application. 
     The embodiments of this application provide a connection member  35  of a rechargeable battery. The connection member  35  includes a guide plate  353  and a first connecting plate  351  integrally formed on the guide plate  353 . The first connecting plate  351  is disposed in a bendable manner relative to the guide plate  353 . At least one indentation  35 K is present between the first connecting plate  351  and the guide plate  353 . 
     The at least one indentation  35 K is provided to form a thin part at the at least one indentation  35 K between the first connecting plate  351  and the guide plate  353 , so that the bending position is more accurate when the first connecting plate  351  is bent relative to the guide plate  353 . This is conducive to an accurate size of the connection member  35  being bent, and is also helpful for the rechargeable battery to successfully assemble the battery core  100 , the connection member  35 , and a housing. Moreover, the at least one indentation  35 K makes bending of the first connecting plate  351  more labor-saving, thereby reducing possible damage caused by bending to the battery core  100  and a tab  120  of the battery core. 
     The rechargeable battery in the embodiments of this application includes the foregoing connection member, and therefore has the same advantages as the connection member. 
     With reference to  FIG.  1    to  FIG.  23   , the rechargeable battery and the connection member according to the embodiments of this application are described in more detail below. 
     The connection member  35  is configured to electrically connect a battery core  100  of a rechargeable battery to outside of the rechargeable battery. As shown in  FIG.  1    to  FIG.  6   , the connection member  35  includes the guide plate  353 , the first connecting plate  351  connected to at a side edge of the guide plate  353  in a width direction, and a second connecting plate  352  connected to the guide plate  353  and configured to electrically connect to the outside of the rechargeable battery. The first connecting plate  351  is configured to connect to the battery core  100 . The second connecting plate  352  is configured to electrically connect to the outside of rechargeable battery. The at least one indentation  35 K is present between the first connecting plate  351  and the guide plate  353  that are of the connection member  35 . 
     The at least one indentation  35 K is provided to form a thin part at the at least one indentation  35 K between the first connecting plate  351  and the guide plate  353 , so that a bending position is more accurate when the first connecting plate  351  is bent relative to the guide plate  353 . This is conducive to an accurate size of the connection member  35  being bent, and is also helpful for the rechargeable battery to successfully assemble the battery core  100 , the connection member  35 , and a housing. Moreover, the at least one indentation  35 K makes bending of the first connecting plate  351  more labor-saving, thereby reducing possible damage caused by bending to the battery core  100  and a tab  120  of the battery core. 
     In this embodiment, in an implementation, the connection member  35  includes the at least one indentation  35 K provided on a side, of the connection member  35 , to which pressure is applied when the first connecting plate  351  is bent relative to the guide plate  353 . Specifically, as shown in  FIG.  15   , when the first connecting plate  351  is bent inwards relative to the guide plate  353 , the at least one indentation  35 K is provided on an inner side of the connection member  35  because pressure is applied to the inner side of the connection member  35 . As shown in  FIG.  23   , when the first connecting plate  351  is bent outwards relative to the guide plate  353 , the at least one indentation  35 K is provided on an outer side of the connection member  35  because pressure is applied to the outer side of the connection member  35 . Further, in an implementation, all the indentations  35 K of the connection member  35  are provided on the side, of the connection member  35 , to which pressure is applied when the first connecting plate  351  is bent relative to the guide plate  353 . In this embodiment, the at least one indentation  35 K is provided on the side, of the connection member  35 , to which pressure is applied when the first connecting plate  351  is bent relative to the guide plate  353 , so that there is no tensile stress at the at least one indentation when the first connecting plate  351  is bent. In this way, a probability of breakage of the connection member  35  during bending is decreased compared with a case in which the at least one indentation is provided on a side (corresponding to the outer side of the connection member  35  in  FIG.  15    or corresponding to the inner side of the connection member  35  in  FIG.  23   ), of the connection member  35 , to which a tensile force is applied when the first connecting plate  351  is bent relative to the guide plate  353 . 
     To implement effective bending of the connection member  35  and effectively control a spatial size of the connection member  35  being bent, in an implementation, as shown in  FIG.  6   , the guide plate  353  includes a main plate body  3531  and a flanged portion  3532 . The flanged portion  3532  is arranged on a side edge of the main plate body  3531  in a width direction Y. The first connecting plate  351  is connected to the guide plate  353  through the flanged portion  3532 . A distance L between the at least one indentation  35 K and the main plate body  3531  of the guide plate  353  is 1 to 3 times a thickness of the main plate body. As shown in  FIG.  3   , the distance L is a distance between a deepest position (for example, an arc bottom of the at least one indentation whose cross-section is arc-shaped) of the at least one indentation  35 K or a mid-surface (for example, a mid-surface that is of a bottom of the at least one indentation with a trapezoidal cross-section and that is parallel to the main plate body  3531 ) of the main plate body  3531  parallel to the deepest position and a surface, of the main plate body  3531 , closer to the at least one indentation  35 K when the first connecting plate  351  is not bent relative to the guide plate  353 . 
     In some embodiments, a depth of the at least one indentation  35 K is ¼ to ⅓ of a minimum plate thickness at a position of the at least one indentation  35 K when the at least one indentation is not provided. When a size of the at least one indentation  35 K is properly set, an accurate bending position can be obtained, to ensure a connection strength between the first connecting plate  351  and the guide plate  353  and prevent an excessively deep indentation from affecting a current flow capacity of the connection member  35  at the at least one indentation  35 K. 
     As shown in  FIG.  1   , in this embodiment, the at least one indentation  35 K is provided continuously along a full length of the bending position between the first connecting plate  351  and the guide plate  353 . In some embodiments not shown in the figures, the at least one indentation may also be provided continuously along a partial length of the bending position between the first connecting plate and the guide plate. In some other embodiments not shown in the figures, the at least one indentation  35 K includes a plurality of indentation segments provided intermittently along the full or partial length of the bending position between the first connecting plate and the guide plate. 
     The at least one indentation  35 K may be in a variety of cross-sectional shapes. The cross-sectional shape of the at least one indentation  35 K may be a curve or a polygonal line or a combination of a curve and a straight line. For example, the cross-sectional shape of the at least one indentation  35 K may be an arc shown in  FIG.  3   , or a trapezoid shown in  FIG.  9   , or a triangle shown in  FIG.  10   . The indentations  35 K in different shapes have different advantages. For example, the indentation with the arc-shaped cross-section can effectively prevent or alleviate stress concentration. The indentation with the trapezoid-shaped cross-section has a relatively shallow depth, making it easy to ensure the current flow capacity from the first connecting plate  351  to the guide plate  353 . The indentation with the triangular cross-section is easier to process, and a position of the first connecting plate  351  being bent can be relatively more accurate. 
     In some embodiments, an opening of the at least one indentation  35 K is larger than a bottom of the at least one indentation  35 K before the first connecting plate  351  is bent relative to the guide plate  353 . For example, for each type of indentation shown in  FIG.  3   ,  FIG.  9   , or  FIG.  10   , the opening of the at least one indentation forms an elongated opening, the bottom is either a straight line (a bottom of the arc-shaped cross-section shown in  FIG.  3   , and a bottom of the trapezoid-shaped cross-section shown in  FIG.  10   ) or an elongated bottom smaller than the elongated opening (for example, a bottom of the trapezoid-shaped cross-section shown in  FIG.  9   ). The opening of the at least one indentation  35 K is larger than the bottom of the at least one indentation  35 K, thereby ensuring the bending position of the first connecting plate  351  and easy processing of the at least one indentation  35 K. Furthermore, in the case in which the at least one indentation  35 K is provided on a side, of the connection member  35 , to which pressure is applied when the first connecting plate  351  is bent relative to the guide plate  353 , the opening of the at least one indentation  35 K can be protected against pressing or less pressing during the bending of the first connecting plate, so that the first connecting plate  351  can be more easily bent in place. 
     In addition, in an implementation, ends of the bending position between the first connecting plate  351  and the guide plate  353  include a first root and a second root that are respectively arranged at opposite ends of the bending position. The connection member  35  includes a first groove  35 B arranged at the first root and disposed on the first connecting plate  351  and the guide plate  353  and a second groove  35 C arranged at the second root and disposed on the first connecting plate  351  and the guide plate  353 . 
     As shown in  FIG.  1    to  FIG.  6   , in the connection member  35  of this embodiment, the two first connecting plates  351  are respectively disposed on two side edges of the guide plate  353  in the width direction Y. The first groove  35 B is arranged at the first root of the bending position, to be specific, at the tops of  FIG.  1    and  FIG.  4   . The second groove  35 C is arranged at the second root opposite to the first root of the bending position, to be specific, at the bottoms of  FIG.  1    and  FIG.  4   . As shown in  FIG.  1    and  FIG.  4   , the bending position extends along a height direction Z of the connection member  35 , the first groove  35 B is recessed downward from an upper edge of the bending position, and the second groove  35 C is recessed upward from a lower edge of the bending position. 
     Providing the first groove  35 B and the second groove  35 C can protect the connection member  35  against damage to the ends of the bending position during bending, and effectively alleviate a crack problem of the ends occurred during bending for the connection member  35 . 
     In some embodiments, the first groove  35 B and the second groove  35 C may be smoothly connected to the first connecting plate  351  and the guide plate  353 . 
     In addition, in an implementation, a cross-section of the groove is a smooth curved section or a smoothly connected multi-section line. For example, the first groove  35 B or the second groove  35 C may be a square groove connected through a circular arc at the corner. 
     In other embodiments not shown in the figures, the groove may alternatively be a U-shaped groove, an arc-shaped groove, or the like. A cross-section shape of the arc-shaped groove may be, for example, a semicircular or a major arc. 
     With the foregoing disposition, no stress is concentrated at the ends of the bending position and/or near the ends of the bending position, which helps protect the connection member  35  against partial crack caused by bending of the first connecting plate  351 . 
     As shown in  FIG.  7    and  FIG.  8   , in the rechargeable battery according to some embodiments of this application, the rechargeable battery mainly includes a housing, a top cover  30 , a battery core  100 , and a connection member  35 . The housing is not shown in the figures. A longitudinal direction of the battery core  100  is consistent with a longitudinal direction X; a thickness direction of the battery core  100  is consistent with a width direction Y; and a height direction of the battery core  100  is consistent with a height direction Z. 
     The top cover  30  has an explosion-proof valve  32 , an injection hole  33 , a positive electrode component  31 , and a negative electrode component  34 . In  FIG.  7   , W represents a welding position between the first connecting plate  351  and a tab  120 . 
     The housing and the top cover  30  form an installation space. The battery core  100 , the guide plate  353  of the connection member  35 , and a portion of the first connecting plate  351  below the top cover  30  are arranged within the installation space. The second connecting plate  352  of the connection member  35  is connected to the electrode components on the top cover  30 . In  FIG.  7   , a connection hole is provided in the second connecting plate  352 , and the second connecting plate  352  is connected to the electrode component through the connection hole. 
     As shown in  FIG.  7   , the electrode component on the top cover  30  includes: the positive electrode component  31  configured to electrically connect to a positive electrode of the battery core  100 , and the negative electrode component  34  configured to electrically connect to a negative electrode of the battery core  100 . The explosion-proof valve  32  is further disposed on the top cover  30 . Another structure such the injection hole  33  may be further provided in the top cover  30 . 
     The connection member  35  of the rechargeable battery may be first fastened to the top cover  30  and the electrode component on the top cover  30 , and then connected to the battery core  100 . During connection of the connection member  35  and the battery core  100 , after a position of the guide plate  353  relative to the core body  110  is determined, the first connecting plate  351  is fastened to the tab  120  at an angle with respect to an end surface of the core body  110 ; then the first connecting plate  351  is bent to an assembly position, for example, the first connecting plate  351  in this embodiment is bent to be parallel to the end surface of the core body  110 . After assembly of the connection member  35  and the battery core  100  is complete, the connection member  35  and the battery core  100  are placed into the housing together. After assembly of the connection member  35  and the battery core  100  is complete, the top cover  30  is placed over an opening of the housing, and then the top cover  30  is sealed to the housing. 
     As shown in  FIG.  11    to  FIG.  13   , a battery core  100  includes a core body  110  and a tab  120  extending from the core body  110 . 
     The battery core  100  is a square core formed by stacking and winding a positive plate, a separator, and a negative plate. A width direction of the positive plate, the separator, and the negative plate forms a longitudinal direction of the battery core  100 . 
     The positive plate and negative plate each include a substrate and an active substance coated on the substrate. An area coated with the active substance on the substrate forms a coated area. The separator is used to separate the positive plate from the negative plate, to avoid short circuits inside the rechargeable battery. The substrate of the positive plate may be a first metal foil, for example, an aluminum foil. The substrate of the negative plate may be a second metal foil, for example, a copper foil. 
     The tab  120  includes a positive tab and a negative tab. The positive tab is formed by a portion, of the first metal foil, not coated with an active substance on one side edge. The negative tab is formed by a portion, of the second metal foil, not coated with an active substance on one side edge. In this embodiment, the positive tab and the negative tab are arranged at two ends of the battery core  100  in the longitudinal direction and protrude beyond the corresponding ends of the separator. 
     As shown in  FIG.  11    to  FIG.  13   , in the battery core  100  of this embodiment, the tab  120  extends from a side of the core body  110  in the thickness direction. As shown in  FIG.  11   , the tab  120  extends from a rear side of the core body  110  in the thickness direction, but not extending from a front side of the core body  110  in the thickness direction, thereby forming a vacancy  122  in the thickness direction. With such disposition, a size occupied by the tab  120  in the longitudinal direction of the battery core  100  becomes thinner after the first connecting plate  351  is bent relative to the guide plate  353 , so that the first connecting plate  351  can be disposed closer to the core body  110 , and an overall size of the connection member  35  and the battery core  100  in the longitudinal direction is reduced, thereby increasing the energy density of the rechargeable battery. 
     In this embodiment, the position of the positive tab is consistent with that of the negative tab in the thickness direction. 
     As shown in  FIG.  11    and  FIG.  12   , the tab  120  is arranged in the middle of the core body  110  in the height direction. As shown in  FIG.  12   , in the height direction of the battery core  100 , a vacancy  121  is separately formed on the top and bottom of the tab  120 . With such disposition, the tab  120  is easier to bend, so that the tab  120  is arranged between the first connecting plate  351  and the core body  110 . 
     The connection member  35  is arranged at an end of the battery core  100  in the longitudinal direction. In this embodiment, one connection member  35  is disposed at each end of the battery core  100  in the longitudinal direction. One connection member  35  is connected to the positive tab of the battery core  100 , and the other connection member is connected to the negative tab of the battery core  100 . The connection member  35  connected to the positive tab of the battery core  100  is connected to the positive electrode component  31  on the top cover  30 , and the connection member  35  connected to the negative tab of the battery core  100  is connected to the negative electrode component  34  on the top cover  30 , so that the tab  120  can be electrically connected to the corresponding electrode component through the connection member  35 . 
     In this embodiment, a manner of connecting the connection member  35  to the tab  120  of the corresponding end is the same for both ends of the battery core  100 . Therefore, the following uses the connection member  35  at only one end of the battery core  100  in the longitudinal direction X and a connection relationship between the connection member  35  and the battery core  100  as an example for description. 
     As shown in  FIG.  1    to  FIG.  8   , the connection member  35  includes two first connecting plates  351  that are respectively connected on two sides of the guide plate  353  in the width direction. The second connecting plate  352  is arranged above the battery core  100 . Before the first connecting plate  351  is bent relative to the guide plate  353 , an extension direction of the second connecting plate  352  is opposite to that of the first connecting plate  351 . After assembly of the rechargeable battery is complete, the second connecting plate  352  is bent, relative to the guide plate  353 , towards the side of the battery core  100  to be parallel to the end surface of the core body  100 . In this embodiment, the second connecting plate  352  is electrically connected to the electrode component. In the embodiments not shown in the figures, the second connecting plate may alternatively be used as an electrode component of the rechargeable battery, with no need to specially dispose an electrode component. 
     As shown in  FIG.  7    and  FIG.  8   , in this embodiment, the first connecting plate  351  after being bent is arranged on the inner side of the guide plate  353  in the width direction and parallel to the end surface of the core body  110 , that is, perpendicular to the longitudinal direction X of the battery core  100 . 
     In this embodiment, the connection member  35  is formed by a whole sheet material. During assembly of the connection member  35  and the battery core, after the position of the guide plate  353  relative to the battery core  100  is determined, the first connecting plate  351  is fastened to the tab  120  to be parallel to the longitudinal direction X of the battery core  100 , and then the first connecting plate  351  is bent towards the inner side of the guide plate  353 , to complete assembly of the connection member  35  and the battery core  100 . 
     In some embodiments not shown in the figures, after the position of the guide plate  353  relative to the battery core  100  is determined, the first connecting plate  351  may alternatively be fastened to the tab  120  at an angle deviated away from the longitudinal direction X of the battery core  100 , and then the first connecting plate  351  is bent towards the inner side of the guide plate  353 , to complete the assembly of the connection member  35  and the battery core  100 . 
     The first connecting plate  351  of the connection member  35  and the tab  120  of the battery core  100  may be electrically connected by ultrasonic welding, laser welding, or resistance welding, and also be fastened to some strength extent. After welding connection, the first connecting plate  351  of the connection member  35  is bent inwards, an internal space occupied by the connection member  35  and the battery core  100  in the longitudinal direction X is reduced, thereby increasing the energy density. 
     In this embodiment, the tab  120  of each of the two battery cores  100  is arranged on a side farther from the other battery core  100 . In the embodiments not shown in the figures, the tab  120  of each of the two battery cores  100  may alternatively be arranged on a side closer to the other battery core  100 . 
     The first connecting plate  351  is bent inwards relative to the guide plate  353 , effectively reducing the space occupied by the connection member  35  at the end in the longitudinal direction X. Moreover, the tab  120  extends from a side in the width direction Y, effectively reducing a thickness of the tab  120  and further reducing a space occupied by a connection position between the connection member  35  and the tab  120 . Therefore, the space utilization of the rechargeable battery and the energy density of the rechargeable battery are effectively improved. 
     In addition, due to reduction of the overall thickness of the tab  120 , a distance between the tab  120  and the connection member  35  in the longitudinal direction X can be set smaller, so that an active space of the tab  120  in the longitudinal direction X can be effectively reduced. The tab  120  is not prone to damage when the rechargeable battery is vibrated or shocked, and a probability of inserting the tab  120  into the core body  110  due to pressing is reduced. In this way, a risk of short circuits inside the rechargeable battery is reduced and a service life and safety performance of the battery core  100  are improved. 
     In addition, in this embodiment, as shown in  FIG.  7    and  FIG.  8   , the rechargeable battery further includes a gasket  310  that is fastened to the first connecting plate  351  and the tab  120 , and the tab  120  is sandwiched between the first connecting plate  351  and the gasket  310 . 
     The gasket  310  is provided, to reduce direct shock on the tab  120  arranged on the side, of the connection member  35 , farther from the core body  110  after the rechargeable battery is vibrated and shocked, to protect the tab  120  and improve the service life of the rechargeable battery. 
     In the embodiments shown in  FIG.  14    and  FIG.  15   , in addition to the groove disposed in the connection member  35 , a thickness of the first connecting plate  351  may be set to be smaller than a thickness of the guide plate  353 , and the at least one indentation  35 K is also provided. The portion, of the guide plate  353 , connected to the first connecting plate  351  becomes gradually thinner in the direction from the guide plate  353  to the first connecting plate  351 . The tabs  120  of the two battery cores  100  are respectively arranged on the sides farther from the other battery core  100 . The tab  120  is fastened to the first connecting plate  351 , and no gasket is disposed on the side, of the tab  120 , opposite to the first connecting plate  351 . The two first connecting plates  351  of the connection member  35  are bent towards the inner side of the guide plate  353 . 
     Compared with a connection member having a same thickness as the guide plate  353  and the first connecting plate  351 , the thickness of the first connecting plate  351  is less than the thickness of the guide plate  353 , so that a space occupied in the rechargeable battery by the connection member  35  after bending can be further reduced, thereby further improving the energy density of the rechargeable battery. Moreover, because the thickness of the first connecting plate  351  decreases, welding and assembly quality of the first connecting plate  351  and the tab  120  of the rechargeable battery can be effectively improved. However, the thickness of the guide plate  353  remains relatively large, to reduce a resistance of the guide plate  353 . In this way, an internal resistance of the rechargeable battery can meet a requirement, to ensure that the rechargeable battery does not heat abruptly when the rechargeable battery is charged or discharged at a large rate. In addition, the thickness of the first connecting plate  351  is smaller than that of the guide plate  353 , conducive to bending of the first connecting plate  351 . Therefore, this ensures a relative position of the connection member  35  and the battery core  100  after bending, facilitates assembly, and further helps reduce damage to the core body  110  or the tab  120  during bending. 
     In some embodiments not shown in the figures, the first connecting plate  351  may alternatively be bent outwards. In an implementation, at least a portion of the guide plate  353  protrudes, relative to the first connecting plate  351 , towards the core body  110  to form a protrusion. In an implementation, the protrusion abuts against the battery core  100 . 
     As shown in  FIG.  16    to  FIG.  18   , in some embodiments, the connection member  35  includes the guide plate  353 , two first connecting plates  351  connected to both side edges of the guide plate  353  in the width direction, and a second connecting plate  352  connected to the guide plate  353  and electrically connected to the outside of the rechargeable battery. The at least one indentation  35 K is present between the first connecting plate  351  and the guide plate  353  that are of the connection member  35 . Compared with the embodiments shown in  FIG.  1    to  FIG.  8   , the first connecting plate  351  in this embodiment is bent towards the outer side of the guide plate  353 . 
     As shown in  FIG.  19    to  FIG.  23   , the rechargeable battery includes the housing, the top cover  30 , the battery core  100 , and the connection member  35 . The top cover  30  is provided with the positive electrode component  31  configured to electrically connect to the positive electrode of the battery core  100 , the negative electrode component  34  configured to electrically connect to the negative electrode of the battery core  100 , and the explosion-proof valve  32 . 
     In this embodiment, the tab  120  extends from a side of the core body  110  in the thickness direction (that is, the width direction Y). The first connecting plate  351  of the connection member  35  is connected to a side of the guide plate  353  in the width direction. The first connecting plate  351  is connected to the tab  120  and extends towards the outer side of the guide plate  353  in the width direction Y. The first connecting plate  351  is parallel to the end surface of the core body  110 , in other words, the first connecting plate  351  is perpendicular to a longitudinal direction X of the battery core  100 . At least a portion of the guide plate  353  protrudes, relative to the first connecting plate  351 , towards a side of the core body  110  to form a protrusion, and the protrusion abuts against the battery core  100 . 
     Because at least a portion of the guide plate  353  protrudes, relative to the first connecting plate  351 , towards a side of the core body  110  to form a protrusion and the protrusion abuts against the battery core  100 , when the rechargeable battery is vibrated or shocked, the protrusion of the guide plate  353  towards the side of the battery core  100  may come in contact with the battery core  100  to enable the connection member  35  to bear a force, thereby effectively alleviating a tab crack problem caused by vibration or shock on the tab  120 . In addition, an active space of the tab  120  is reduced and a probability of inserting the tab  120  into the core body  110  due to pressing is reduced, thereby reducing a risk of short circuits inside the battery. Because both the probability of crack of the tab  120  and the probability of inserting the tab  120  into the core body  110  are reduced, the service life and safety performance of the battery core  100  can be improved. 
     As shown in  FIG.  23   , the guide plate  353  includes the main plate body  3531  and the flanged portion  3532 . The flanged portion  3532  is arranged at a side edge of the main plate body  3531  in the width direction and extends along a direction away from the battery core  100 . The first connecting plate  351  is connected to the guide plate  353  through the flanged portion  3532 . The main plate body  3531  is a flat plate. The flanged portion  3532  is perpendicular to the main plate body  3531 . 
     In other embodiments not shown in the figures, the flanged portion  3532  may alternatively be tilted towards the inner side of the main plate body  3531 , or the flanged portion  3532  may be tilted towards the outer side of the main plate body  3531 . 
     In this embodiment, the first connecting plate  351  is parallel to the main plate body  3531 . In this case, both the first connecting plate  351  and the main plate  3531  are perpendicular to the longitudinal direction X. 
     In the embodiments not shown in the figures, the first connecting plate  351  and the main plate body  3531  may alternatively form an angle, for example, an outer end of the first connecting plate  351  in the width direction Y may be closer to the core body  110  than an inner end in the width direction Y. 
     In the embodiments shown in  FIG.  19    to  FIG.  23   , the tab  120  of each of the two battery cores  100  may be arranged on a side farther from the other battery core  100 . 
     In some exemplary embodiments, at least a portion of the guide plate  353  is attached to the battery core  100 . In this embodiment, the guide plate  353  is entirely attached to a side of the core body  110 . With such disposition, the tab  120  is less prone to damage and insertion into the core body  110  when the rechargeable battery is vibrated or shocked, further improving the service life and safety performance of the battery core  100 . 
     In this embodiment, the main plate body  3531  of the connection member  35  is attached to the core body  110 , to be specific, attached to an end surface of the separator at an end of the battery core  100  in the longitudinal direction X. The tab  120  barely plays fixing and positioning functions in the longitudinal direction X of the battery core  100 , thereby more effectively protecting the tab  120  against damage. The main plate body  3531  of the connection member  35  is attached to the end surface of the separator of the battery core  100  to tightly compress the battery core  100 , thereby playing a role of supporting, fastening, and positioning the battery core  100  along the longitudinal direction X. This prevents the battery core  100  from shaking inside the housing after the rechargeable battery is assembled. 
     The foregoing embodiments shall not constitute a limitation on this application. 
     For example, in the embodiments not shown in the figures, when the first connecting plate is bent outwards and the guide plate at least partially protrudes, relative to the first connecting plate, towards the core body, the tab of each of the two battery cores may alternatively be arranged on a side closer to the other battery core, to be specific, a position of extending the tab from the core body is arranged on the inner side of the rechargeable battery in the width direction Y. The main plate body of the guide plate abuts against a surface of the tab. 
     For another example, the first connecting plate may alternatively be connected to a set of battery cores. For example, the connection member may include two first connecting plates arranged on both sides in the width direction. Each first connecting plate is connected to a set of battery cores. The tab is disposed on a side of the core body in the thickness direction. The two sets of battery cores may each include two battery cores, and a tab of each of the two battery cores in one set is arranged on a side closer to the other battery core. 
     For the foregoing embodiments of this application, related technical content of other embodiments can be referred to or combined unless otherwise contradicted in the technical features. 
     Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of this application, but not for limiting this application. Although this application is described in detail with reference to the exemplary embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the embodiments or make equivalent replacements to some or all technical features thereof, without departing from the scope of the technical solutions of this application, which are all included in the scope of the technical solutions claimed by this application.