Patent Publication Number: US-2023163385-A1

Title: Battery module and electric device

Description:
CROSS REFERENCE TO THE RELATED APPLICATIONS 
     The present application claims priority to Chinese Patent Application No. 202111385544.0, filed on 22 Nov. 2021, the disclosure of which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     This application relates to the field of energy storage technologies, and in particular, to a battery module and an electric device. 
     BACKGROUND 
     During use of a battery, a circuit board of the battery generates a large amount of heat. To avoid excessively high temperature of the battery, the battery needs to be subjected to heat dissipation. A current conventional heat dissipation method is to add a heat dissipation member between cells, but with such heat dissipation method, limited heat is dissipated for the circuit board. 
     SUMMARY 
     In view of this, it is necessary to provide a battery module and an electric device to improve heat dissipation for a circuit board. 
     An embodiment of this application provides a battery module, including a housing assembly, a cell assembly, a circuit board, and a first connecting member. The housing assembly includes a first side wall and a second side wall. The first side wall is provided with a first through hole. The second side wall is provided with a second through hole. The cell assembly is accommodated in the housing assembly. The cell assembly includes cells. Each cell includes a cell housing, an electrode assembly disposed in the cell housing, and an electrode terminal connecting to the electrode assembly and led out of the cell housing. The circuit board connects to the electrode terminal. The first connecting member connects to the circuit board. The first connecting member is disposed in the first through hole and the second through hole. The first connecting member is provided with a first channel. The first channel communicates with the first through hole and the second through hole. 
     The first connecting member dissipates heat of the circuit board out of the first through hole and the second through hole to an external environment via the first channel, improving heat dissipation for the circuit board, thereby lowering temperature of the battery module. 
     Optionally, in some embodiments of this application, the first side wall and the second side wall are disposed opposite to each other in a first direction. The first side wall is provided with a first protrusion facing towards the second side wall. The first protrusion is at least partially disposed in the first channel. 
     Optionally, in some embodiments of this application, the first side wall is provided with a first protrusion facing towards the second side wall, and the first protrusion connects to an edge of the first through hole. The first protrusion is provided with a first hole. The first hole communicates with the first through hole. The first protrusion is at least partially disposed in the first channel, or the first connecting member is partially located in the first hole. 
     Optionally, in some embodiments of this application, the first connecting member is partially located in the first hole. An adhesive is provided between the first protrusion and the first connecting member. A gap between the first protrusion and the first connecting member is sealed by the adhesive, so that water entering the housing assembly can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module. 
     Optionally, the second side wall is provided with a second protrusion facing towards the first side wall, and the second protrusion is at least partially disposed in the first channel. 
     Optionally, in some embodiments of this application, the second side wall is provided with a second protrusion facing towards the first side wall. The second protrusion connects to an edge of the second through hole. The second protrusion is provided with a second hole. The second hole communicates with the second through hole. The second protrusion is at least partially disposed in the first channel, or the first connecting member is partially located in the second hole. 
     Optionally, in some embodiments of this application, the first connecting member is partially located in the second hole. An adhesive is provided between the second protrusion and the first connecting member. A gap between the second protrusion and the first connecting member is sealed by the adhesive, so that water entering the housing assembly can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module. 
     Optionally, in some embodiments of this application, the first protrusion is disposed in the first channel. The first connecting member is connected to the first side wall. 
     Optionally, in some embodiments of this application, the first connecting member is in contact connection with the first side wall. 
     Optionally, in some embodiments of this application, the first connecting member is connected to the first side wall through glue and the like. 
     Optionally, in some embodiments of this application, in the first direction X, a projection of the first through hole is larger than and covers a projection of the second through hole. A diameter of the first through hole being larger than a diameter of the second through hole enhances convection of air, further improving heat dissipation. 
     Optionally, in some embodiments of this application, a thermally conductive member is further included. The thermally conductive member is disposed between the first connecting member and the electrode terminal. 
     Optionally, in some embodiments of this application, in a second direction perpendicular to the first direction, the circuit board is provided with a plurality of third through holes. One terminal passes through one of the plurality of third through hole to connect to the circuit board. In a third direction, a projection of the first connecting member is located between projections of adjacent third through holes. The third direction is perpendicular to the first direction and the second direction, implementing better heat dissipation for electrode terminals located on two sides of the first connecting member. 
     Optionally, in some embodiments of this application, in the third direction, the projection of the first connecting member and the projection of the third through hole are spaced apart from each other, reducing intervention of the first connecting member and the electrode terminal. 
     Optionally, in some embodiments of this application, a second connecting member is further included. The second connecting member includes a first component disposed between adjacent cells. The first component connects to the first connecting member. The first side wall and the second side wall are disposed opposite each other in the first direction, and in the second direction perpendicular to the first direction, a projection of the first component and a projection of the cell housing at least partially overlap. The first component being disposed between the adjacent cells increases a contact area between the first component and the cell housing, thereby improving heat dissipation for the adjacent cells. 
     Optionally, in some embodiments of this application, the second connecting member further includes a second component connecting to the first component. The second component extends from between adjacent cells. The second component is bent toward the adjacent cells and is in contact connection with the cell. In the first direction, a projection of the second component and a projection of the adjacent cells at least partially overlap. Provision of the second component increases a contact area between the second connecting member and the cell housing, thereby further improving heat dissipation for the cell. 
     Optionally, in some embodiments of this application, the second component is in contact connection with the housing assembly. Heat is transferred to the housing assembly and is dissipated through the housing assembly, thereby further improving heat dissipation for the battery module. 
     Optionally, in some embodiments of this application, the first connecting member and the second connecting member are integrally formed through bending to enhance structural strength of the first connecting member and the second connecting member. 
     Optionally, in some embodiments of this application, surfaces of the first connecting member and the second connecting member are provided with an insulation layer. 
     Optionally, in some embodiments of this application, the cell housing includes a first portion and a second portion. The electrode assembly is disposed on the first portion. The second portion connects to the first portion. The electrode terminal extends from the second portion. The first portion and the second portion fit to form a third depression. The first connecting member is at least partially disposed in the third depression. 
     Optionally, in some embodiments of this application, a first structural member is further included. The first structural member is provided with a fourth depression. The circuit board is disposed in the fourth depression. The first structural member is provided with a first opening and a second opening. The first connecting member is disposed at the first opening and the second opening. The first connecting member is at least partially located in the second depression. 
     An embodiment of this application further provides an electric device, including the battery module according to any one of the foregoing embodiments. 
     In the foregoing battery module and electric device, the first connecting member dissipates heat of the circuit board and the cell assembly out of the first through hole and the second through hole to an external environment via the first channel, improving heat dissipation for the circuit board, thereby lowering temperature of the battery module. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a structural schematic diagram of a battery module according to some embodiments. 
         FIG.  2    is a schematic diagram of a structure inside a battery module according to some embodiments. 
         FIG.  3    is a schematic cross-sectional diagram of a first connecting member according to some embodiments. 
         FIG.  4    is a structural schematic diagram of a first side wall according to some embodiments. 
         FIG.  5    is a structural schematic diagram of a cell assembly and a first connecting member according to some embodiments. 
         FIG.  6    is a partial schematic exploded view of a battery module according to some embodiments. 
         FIG.  7    is a structural schematic diagram of a cell according to some embodiments. 
         FIG.  8    is a structural schematic diagram of a circuit board and a first connecting member according to some embodiments. 
         FIG.  9    is a structural schematic diagram of a first structural member and a first connecting member according to some embodiments. 
         FIG.  10    is a structural schematic diagram of the first structural member according to  FIG.  9    from another perspective. 
         FIG.  11    is a structural schematic diagram of a second connecting member and a cell according to some embodiments. 
         FIG.  12    is a schematic exploded view of a second connecting member and a cell according to some embodiments. 
         FIG.  13    is a structural schematic diagram of a second connecting member and a cell according to some embodiments from another perspective. 
         FIG.  14    is a structural schematic diagram of an electric device according to an embodiment. 
     
    
    
     REFERENCE SIGNS OF MAIN COMPONENTS 
     
         
         
           
             battery module  100   
             housing assembly  10   
             first through hole  10   a    
             second through hole  10   b    
             first side wall  11   
             first protrusion  111   
             first hole  1110   
             second side wall  12   
             second protrusion  121   
             second hole  1210   
             first housing  13   
             second housing  14   
             cell assembly  20   
             cell  21   
             first side face  21   a    
             second side face  21   b    
             third side face  21   c    
             cell housing  211   
             first portion  211   a    
             second portion  211   b    
             third depression  211   c    
             electrode terminal  212   
             welding portion  212   a    
             first terminal  212   b    
             second terminal  212   c    
             circuit board  30   
             third through hole  31   
             first connecting member  40   
             first channel  40   a    
             first structural member  50   
             top plate  50   a    
             side plate  50   b    
             fourth depression  51   
             first opening  52   
             second opening  53   
             second connecting member  60   
             first component  61   
             fourth adhesive  61   a    
             first connecting portion  611   
             second connecting portion  612   
             second component  62   
             third connecting portion  621   
             fourth connecting portion  622   
             electric device  200   
             first direction X 
             second direction Y 
             third direction Z 
           
         
       
    
     This application will be further described with reference to the accompanying drawings in the following specific embodiments. 
     DETAILED DESCRIPTION 
     The following 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 only some rather than all of the embodiments of this application. 
     When a component is deemed as being “provided on” another component, it may be directly provided on the another component, or there may be a component in between. When a component is deemed as being “connected to” another component, it may be directly connected to the another component, or there may be a component in between. 
     Unless otherwise defined, all technical and scientific terms used herein shall have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only used to describe specific embodiments, and are not intended to limit this application. The term “and/or” used herein includes any and all combinations of one or more related listed items. 
     It can be understood that when two components are parallel with or perpendicular to each other, a specified included angle may be present between the two components, and the included angle between the two components have an allowable tolerance of 0−±5%. For example, when two components that are perpendicular to each other have a tolerance, and one component tilts close to or away from the other component, a tolerance range between the two components is greater than 0° and is less than or equal to 4.5°. When projections of two components are the same or overlap, the two components have an allowable tolerance of 0−±10%. For example, one component has the same projection as the other component in shape, and projection areas have a tolerance of 0−±10%. 
     The following describes in detail some embodiments of this application with reference to the accompanying drawings. In absence of conflicts, the following embodiments and features in the embodiments may be combined with each other. 
     Referring to  FIG.  1   ,  FIG.  2   , and  FIG.  3   , an embodiment of this application provides a battery module  100 , including a housing assembly  10 , a cell assembly  20 , a circuit board  30 , and a first connecting member  40 . The housing assembly  10  is provided with a first through hole  10   a  and a second through hole  10   b , where the first through hole  10   a  and the second through hole  10   b  communicate with the outside. The cell assembly  20  is disposed in the housing assembly  10 . The circuit board  30  is disposed in the housing assembly  10  and connects to the cell assembly  20 . The first connecting member  40  is located below the circuit board  30 , the first connecting member  40  is provided with a first channel  40   a , and the first channel  40   a  communicates with the first through hole  10   a  and the second through hole  10   b . The first connecting member  40  dissipates heat of the circuit board  30  and the cell assembly  20  out of the first through hole  10   a  and the second through hole  10   b  to an external environment via the first channel  40   a , improving heat dissipation for the circuit board  30 , thereby lowering temperature of the battery module  100 . 
     In an embodiment, the first connecting member  40  is in contact connection with the circuit board  30 . In another embodiment, a gap is provided between the first connecting member  40  and the circuit board  30 . In another embodiment, the first connecting member  40  and the circuit board  30  are connected via the thermally conductive member. Optionally, the thermally conductive member includes at least one of a thermally conductive adhesive or a thermally conductive sheet. 
     In an embodiment, the battery module  100  may use outside air to take away heat of the circuit board  30  and the cell assembly  20  through flow of air. In an embodiment, the battery module  100  may be applied to a device that is in a static state during use, and when the battery module  100  is in a static state, heat dissipation can be implemented through natural air flow or an external air cooling device. In an embodiment, the battery module  100  may be applied to a device that is in a dynamic state during use, for example, a drone or an electric motor bicycle. Because air flow velocity is quicker during moving of the device, quick heat dissipation for the battery module  100  can be implemented. 
     The housing assembly  10  includes a first side wall  11  and a second side wall  12 , the first through hole  10   a  is provided on the first side wall  11 , and the second through hole  10   b  is provided on the second side wall  12 . In an embodiment, the first side wall  11  and the second side wall  12  are disposed opposite each other in a first direction X. In the first direction X, the first through hole  10   a  passes through the first side wall  11 , and the second through hole  10   b  passes through the second side wall  12 . In an embodiment, the first through hole  10   a  and the second through hole  10   b  are both provided in plurality and are the same in quantity, and in the first direction X, a projection of the first through hole  10   a  and a projection of the second through hole  10   b  overlap. When the battery module  100  moves in the first direction X or an air flow direction of the external air cooling device is in the first direction X, the first through hole  10   a  is an air inlet, and the second through hole  10   b  is an air outlet. Air enters through the first through hole  10   a , flows through the first channel  40   a , and flows out of the second through hole  10   b , improving heat dissipation. It can be understood that when the battery module  100  moves in a direction opposite to the first direction X or an air flow direction of the external air cooling device is in a direction opposite to the first direction X, the first through hole  10   a  is an air outlet, and the second through hole  10   b  is an air inlet. 
     In an embodiment, in the first direction X, a projection of the first through hole  10   a  is larger than and covers a projection of the second through hole  10   b . When the battery module  100  moves in the first direction X or an air flow direction of the external air cooling device is in the first direction X, the first through hole  10   a  is an air inlet, and the second through hole  10   b  is an air outlet, with a diameter of the first through hole  10   a  being larger than a diameter of the second through hole  10   b , so as to enhance convection of air, further improving heat dissipation. 
     In another embodiment, the first through hole  10   a  and the second through hole  10   b  are different in quantity. One first through hole  10   a  corresponds to a plurality of second through holes  10   b , or one second through hole  10   b  corresponds to a plurality of first through holes  10   a . For example, one first through hole  10   a  corresponds to two second through holes  10   b , one end of the first connecting member  40  is disposed in the first through hole  10   a , and another end thereof is provided with two branches, where the two branches are both provided with the first channel  40   a , and the two branches are correspondingly disposed in the two second through holes  10   b.    
     In an embodiment, the housing assembly  10  includes a first housing  13  and a second housing  14 . The first housing  13  includes a first side wall  11  and a second side wall  12 . The first housing  13  has a first space, and the cell assembly  20  is disposed in the first space. The second housing  14  connects to the first housing  13  to enclose the first space. 
     In an embodiment, the second housing  14  has a second space, and the cell assembly  20  is at least partially disposed in the second space. In an embodiment, the first housing  13  and the second housing  14  are connected through a snap-fitted manner such as a fastener fitting a fastening hole. In another embodiment, the first housing  13  and the second housing  14  may alternatively be fixedly connected through a fastener such as a screw or a bonding manner such as bonding through adhesive. 
     Referring to  FIG.  3    and  FIG.  4   , in an embodiment, the first side wall  11  is provided with a first protrusion  111 , the first protrusion  111  is disposed facing towards the second side wall  12 , and the first protrusion  111  is at least partially disposed in the first channel  40   a . Optionally, the first protrusion  111  is disposed in the first direction X. 
     Optionally, the first protrusion  111  is disposed surrounding part of a periphery of the first through hole  10   a , and the first protrusion  111  is at least partially disposed in the first channel  40   a . The first protrusion  111  is connected to the first connecting member  40  through a first adhesive (not shown in the figure) to fasten the first connecting member  40 . Optionally, the first protrusion  111  is disposed in the first channel  40   a , and the first connecting member  40  is connected to the first side wall  11 . Optionally, the first connecting member  40  is in contact connection with the first side wall  11 . Optionally, the first connecting member  40  is connected to the first side wall  11  through glue and the like. 
     Optionally, the first protrusion  111  is disposed surrounding the periphery of the first through hole  10   a . Further, the first protrusion  111  is connected to an edge of the first through hole  10   a  in a surrounding manner. The first protrusion  111  is at least partially disposed in the first channel  40   a . The first protrusion  111  connects to the first connecting member  40  and is disposed in the first channel  40   a . The first protrusion  111  is provided with a first hole  1110 , where the first hole  1110  communicates with the first through hole  10   a . A first adhesive is provided between the first protrusion  111  and the first connecting member  40 , and a gap between the first protrusion  111  and the first connecting member  40  is sealed by the first adhesive, so that water entering the housing assembly  10  can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module  100 . Optionally, the first adhesive includes a sealant. Optionally, the first protrusion  111  is disposed in the first channel  40   a , and the first connecting member  40  is connected to the first side wall  11 . Optionally, the first connecting member  40  is in contact connection with the first side wall  11 . Optionally, the first connecting member  40  is connected to the first side wall  11  through glue and the like. 
     In another embodiment, the first connecting member  40  is partially located in the first hole  1110 . An adhesive is provided between the first protrusion  111  and the first connecting member  40 , and a gap between the first protrusion  111  and the first connecting member  40  is sealed through by adhesive, so that water entering the housing assembly  10  can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module  100 . Optionally, the adhesive includes a sealant. 
     In another embodiment, a surface of the first side wall  11  facing towards the second side wall  12  is provided with a first depression (not shown in the figure), and one end of the first connecting member  40  is disposed in the first depression. Optionally, the first depression is disposed surrounding the periphery of the first through hole  10   a . Optionally, a first adhesive is provided between the first depression and the first connecting member  40 . A gap between the first depression and the first connecting member  40  is sealed by the first adhesive, so that water entering the housing assembly  10  can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module  100 . 
     In an embodiment, the second side wall  12  is provided with a second protrusion  121 , the second protrusion  121  is disposed facing towards the first side wall  11 , and the second protrusion  121  is at least partially disposed in the first channel  40   a  and may be used to fasten the first connecting member  40 . Optionally, the second protrusion  121  is disposed in a direction opposite to the first direction X. 
     Optionally, the second protrusion  121  is disposed surrounding part of a periphery of the second through hole  10   b , and the second protrusion  121  is at least partially disposed in the first channel  40   a . The second protrusion  121  is connected to the first connecting member  40  through a second adhesive (not shown in the figure) to fasten the first connecting member  40 . Optionally, the second protrusion  121  is disposed in the first channel  40   a , and the first connecting member  40  is connected to the second side wall  12 . Optionally, the first connecting member  40  is in contact connection with the second side wall  12 . Optionally, the first connecting member  40  is connected to the second side wall  12  through glue and the like. 
     Optionally, the second protrusion  121  is disposed surrounding the periphery of the second through hole  10   b . Further, the second protrusion  121  is connected to an edge of the second through hole  10   b  in a surrounding manner. The second protrusion  121  is at least partially disposed in the first channel  40   a . The second protrusion  121  is connected to one end of the first connecting member  40  away from the first protrusion  111 . The second protrusion  121  is disposed in the first channel  40   a . The second protrusion  121  is provided with a second hole  1210 , where the second hole  1210  communicates with the second through hole  10   b . A second adhesive is provided between the second protrusion  121  and the first connecting member  40 , and a gap between the second protrusion  121  and the first connecting member  40  is sealed by the second adhesive, so that water entering the housing assembly  10  can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module  100 . Optionally, the second adhesive includes a sealant. Optionally, the second protrusion  121  is disposed in the first channel  40   a , and the first connecting member  40  is connected to the second side wall  12 . Optionally, the first connecting member  40  is in contact connection with the second side wall  12 . Optionally, the first connecting member  40  is connected to the second side wall  12  through glue and the like. 
     In another embodiment, the first connecting member  40  is partially located in the second hole  1210 . An adhesive is provided between the second protrusion  121  and the first connecting member  40 , and a gap between the second protrusion  121  and the first connecting member  40  is sealed by the adhesive, so that water entering the housing assembly  10  can be reduced, thereby reducing a risk of short circuit caused by the water entering the battery module  100 . Optionally, the adhesive includes a sealant. 
     In another embodiment, a surface of the second side wall  12  facing towards the first side wall  11  is provided with a second depression (not shown in the figure), and the second depression and the first depression fit to fasten two ends of the first connecting member  40 . 
     Referring to  FIG.  5   ,  FIG.  6   , and  FIG.  7   , in an embodiment, the cell assembly  20  includes a plurality of cells  21  stacked in a second direction Y. The cell  21  includes a cell housing  211 , an electrode assembly (not shown in the figure) disposed in the cell housing  211 , and an electrode terminal  212  connected to the electrode assembly and led out of the cell housing  211 . In an embodiment, the electrode assembly includes a wound structure formed by a positive electrode plate, a negative electrode plate, and a separator through winding. In some other embodiments, the electrode assembly may alternatively be of a laminated structure, that is, the positive electrode plate, the separator, and the negative electrode plate are sequentially stacked to form an electrode assembly unit, and then a plurality of electrode assembly units are stacked to form the electrode assembly. In an embodiment, the second direction Y is perpendicular to the first direction X. Optionally, the cell housing  211  includes an aluminum-plastic film. Optionally, the cell  21  includes a pouch cell. In an embodiment, in a third direction Z, a projection of the circuit board  30  and a projection of a part of the electrode terminal  212  extending from the cell housing  211  overlap, where the third direction Z is perpendicular to the first direction X and the second direction Y. 
     In an embodiment, the cell housing  211  includes a first portion  211   a  and a second portion  211   b , where the first portion  211   a  accommodates the electrode assembly, the second portion  211   b  connects to the first portion  211   a , and the electrode terminal  212  extends from the second portion  211   b . The first portion  211   a  and the second portion  211   b  fit to form a third depression  211   c . The first connecting member  40  is at least partially located in the third depression  211   c  to use space of the third depression  211   c , reducing space occupied by the first connecting member  40 . 
     In an embodiment, the electrode terminal  212  is connected to the circuit board  30  and can conduct heat to the circuit board  30 , resulting in high temperature of the circuit board  30 . In this application, the first connecting member  40  is disposed below the circuit board  30 , so that heat is dissipated out of the first through hole  10   a  and the second through hole  10   b  to an external environment via the first channel  40   a , improving heat dissipation for the circuit board  30 . 
     In an embodiment, temperature around the electrode terminal  212  is higher than temperature around the electrode assembly. The electrode terminal  212  and the electrode assembly have a great temperature difference, causing damage to the cell  21  under a long-term cycling condition and shortening service life of the battery module  100 . In this application, the first connecting member  40  is disposed in the third depression  211   c  and is located at a position of the electrode terminal  212 , which can take away heat around the electrode terminal  212  and lower temperature of the electrode terminal  212  of the cell  21  in a timely manner, thereby reducing temperature difference between the electrode terminal  212  and the electrode assembly and prolonging service life of the battery module  100 . 
     In an embodiment, the circuit board  30  is provided with an electronic component, and the first connecting member  40  can further improve heat dissipation for the electronic component, prolonging service life of the electronic component and the circuit board  30 . 
     In an embodiment, the electrode terminal  212  is provided with a welding portion  212   a  extending out of the cell housing  211 , where the welding portion  212   a  is formed by the electrode terminal  212  through bending. The electrode terminals  212  of adjacent cells  21  are bent toward each other and are connected to the circuit board  30 . In an embodiment, the electrode terminal  212  includes a first terminal  212   b  and a second terminal  212   c , the first terminal  212   b  and the second terminal  212   c  are opposite in polarity, one of the first terminal  212   b  and the second terminal  212   c  is a positive electrode terminal, and the other is a negative electrode terminal. In the third direction Z, a projection of the first terminal  212   b  of a cell  21  and a projection of the second terminal  212   c  of an adjacent cell  21  at least partially overlap. The third direction Z is perpendicular to the first direction X and the second direction Y. The first terminal  212   b  and the second terminal  212   c  of adjacent cells are bent toward each other, and the welding portion  212   a  of the first terminal  212   b  and the welding portion  212   a  of the second terminal  212   c  are stacked and connected with each other. The welding portions  212   a  of adjacent cells  21  are connected with each other, so that the welding portions  212   a  are connected to the circuit board  30 , reducing steps of a manufacture process. 
     In another embodiment, in the third direction Z, the projection of the first terminal  212   b  of the cell  21  and a projection of the first terminal  212   b  of the adjacent cell  21  may also at least partially overlap; and the first terminal  212   b  of the cell  21  and the first terminal  212   b  of the adjacent cell  21  are connected through the circuit board  30  to implement parallel connection between the cells  21 . 
     In an embodiment, for the electrode terminal  212  and the first connecting member  40 , the thermally conductive member connects the first connecting member  40  and the electrode terminal  212  and transfers heat of the electrode terminal  212  to the first connecting member  40 . 
     In an embodiment, the circuit board  30  is provided with a plurality of groups of communicating holes disposed in the first direction X, where each group of the communicating holes includes a plurality of third through holes  31 , and the plurality of third through holes  31  are disposed in the second direction Y. the third through hole  31  extends in the first direction X. The electrode terminal  212  passes through the third through hole  31  and connects to the circuit board  30  through the welding portion  212   a . Further, the welding portion  212   a  and the circuit board  30  are connected through welding, where the welding includes laser welding, ultrasonic welding, and the like. In another embodiment, the welding portion  212   a  and the circuit board  30  may alternatively be connected through another manner such as a conductive adhesive. In an embodiment, the circuit board  30  may be a circuit board with a battery management system to implement intelligent management and maintenance of all battery units, reduce overcharge and over discharge of a battery, prolong service life of the battery, and monitor a condition of the battery. 
     In some embodiments, the circuit board  30  includes a conductive sheet (not shown in the figure), where the welding portion  212   a  is welded to the conductive sheet. 
     In an embodiment, when observed in a direction opposite to the third direction Z, the first connecting member  40  is disposed between adjacent third through holes  31 , implementing better heat dissipation for the welding portions  212   a  located on two sides of the first connecting member  40 . In the third direction Z, a projection of the first connecting member  40  is located between projections of adjacent third through holes  31 . Further, in the third direction Z, the projection of the first connecting member  40  and the projection of the third through hole  31  are spaced apart from each other, reducing interference between the first connecting member  40  and the electrode terminal  212 . 
     In an embodiment, the first connecting member  40  includes a thermally conductive material, for example, aluminum. In an embodiment, the first connecting member  40  includes a thermally conductive metal material and a thermally conductive insulation material, where the insulation material may cover an outer surface of the thermally conductive metal material to enhance insulation between the first connecting member  40 , the cell, and the circuit board. 
     In an embodiment, in the first direction X, two ends of the first connecting member  40  protrude out of the circuit board  30 , facilitating assembly and reducing interference between the circuit board  30  and the first connecting member  40 . 
     Referring to  FIG.  6   ,  FIG.  9   , and  FIG.  10   , in an embodiment, the battery module  100  further includes a first structural member  50 , where the first structural member  50  includes a top plate  50   a  and a side plate  50   b  connecting to a peripheral side of the top plate  50   a , the top plate  50   a  and the side plate  50   b  form a fourth depression  51 , and the circuit board  30  is disposed in the fourth depression  51 . The side plate  50   b  is provided with a first opening  52  and a second opening  53 , where the first opening  52  and the second opening  53  may be disposed in the first direction X. One end of the first connecting member  40  is disposed at the first opening  52 , and another end thereof is disposed at the second opening  53 . The circuit board  30  is disposed between the top plate  50   a  and the first connecting member  40 , and the first connecting member  40  is at least partially disposed in the fourth depression  51  to limit the circuit board  30  in the fourth depression  51 . Optionally, in the first direction X, the projection of the first connecting member  40  and a projection of the side plate  50   b  partially overlap, enabling the first connecting member  40  to be partially disposed in the fourth depression  51 . Optionally, in the first direction X, the projection of the first connecting member  40  and the projection of the side plate  50   b  overlap, so that the first connecting member  40  is entirely disposed in the fourth depression  51 . Optionally, two ends of the first connecting member  40  protrude out of the side plate  50   b  and are connected to the first protrusion  111  and the second protrusion  121 , facilitating limitation on a position of the first connecting member  40 . Optionally, an insulation layer is provided in the fourth depression  51  to bond and fasten the circuit board  30 , the first connecting member  40 , and the first structural member  50 . The insulation layer may be formed of an insulation material cured after being injected into the fourth depression  51 . The insulation material includes at least one of a thermally conductive adhesive or a potting adhesive. 
     In an embodiment, the first connecting member  40  is disposed at the first opening  52  and the second opening  53  through a third adhesive. Optionally, the third adhesive includes a sealant. 
     Referring to  FIG.  11   ,  FIG.  12   , and  FIG.  13   , in an embodiment, the battery module  100  includes a second connecting member  60 . The second connecting member  60  connects to the first connecting member  40 , and surfaces of the first connecting member  40  and the second connecting member  60  are provided with an insulation layer, reducing a risk of short circuit between the first connecting member  40  and the second connecting member  60  and the cell  21  and the circuit board  30 . 
     In an embodiment, the second connecting member  60  includes a first component  61 , and the first connecting member  40  and the first component  61  are disposed in the third direction Z. The first component  61  is disposed between adjacent cells  21 , implementing heat dissipation for the adjacent cells  21 . In the second direction Y, a projection of the first component  61  and a projection of the cell housing  211  at least partially overlap. Optionally, in the second direction Y, the projection of the first component  61  is located in a projection area of the cell housing  211 . The first component  61  being disposed between the adjacent cells  21  enables two surfaces of the cell  21  disposed in the second direction Y both to be in contact connection with the first component  61  and the first component  61  to cover two surfaces of the cell housing  211 , increasing a contact area between the first component  61  and the cell housing  211  and improving heat dissipation for the adjacent cells  21 . 
     In an embodiment, the first component  61  is bonded to the cell housing  211  through a fourth adhesive  61   a.    
     In an embodiment, the second connecting member  60  further includes a second component  62 , where the second component  62  connects to the first component  61 . The second component  62  extends from between adjacent cells  21  and is bent toward the cell  21 , enabling the second component  62  to be in contact connection with the cell housing  211 . In the first direction X, a projection of the second component  62  and a projection of the cell  21  at least partially overlap. The second component  62  being in contact connection with the cell housing  211  increases a contact area between the second connecting member  60  and the cell housing  211 , so that heat is conducted to the second component  62  through the cell housing  211  and then conducted to the first connecting member  40  through the second component  62 , thereby improving heat dissipation for the cell  21 . In an embodiment, the second component  62  is in contact connection with the housing assembly  10 , so that heat is transferred to the housing assembly  10  and is dissipated by the housing assembly  10 , thereby further improving heat dissipation for the battery module  100 . 
     Further, the first component  61  includes a first connecting portion  611  and a second connecting portion  612 . The first connecting portion  611  and the second connecting portion  612  connect to the first connecting member  40 . The first connecting portion  611  and the second connecting portion  612  are disposed opposite each other in the second direction Y, where the first connecting portion  611  is in contact connection with one of two adjacent cells  21 , and the second connecting portion  612  is in contact connection with the other of the two adjacent cells  21 . The second component  62  includes a third connecting portion  621  and a fourth connecting portion  622 . The third connecting portion  621  connects to the first connecting portion  611  and extends from between adjacent cells  21 . The third connecting portion  621  is bent toward a cell  21  connected to the first connecting portion  611  and is in contact connection with the cell  21 . The fourth connecting portion  622  connects to the second connecting portion  612  and extends from between adjacent cells  21 . The third connecting portion  621  is bent toward a cell  21  connected to the second connecting portion  612  and is in contact connection with the cell  21 . A contact area between the second component  62  and the adjacent cells  21  is further increased, thereby further improving heat dissipation for the cell  21 . 
     Further, the cell housing  211  includes a first side face  21   a , a second side face  21   b , and a third side face  21   c . The first connecting portion  611  connects to a plurality of third connecting portions  621 , and the second connecting portion  612  connects to a plurality of fourth connecting portions  622 . One of the third connecting portions  621  and one of the fourth connecting portions  622  extend from between adjacent cells  21  and are in contact connection with the first side face  21   a , another one of the third connecting portions  621  and another one of the fourth connecting portions  622  extend from between adjacent cells  21  and are in contact connection with the second side face  21   b , still another one of the third connecting portions  621  and still another one of the fourth connecting portions  622  extend from between adjacent cells  21  and are in contact connection with the third side face  21   c , and the second component  62  is disposed at the periphery of the cell housing  211 , further improving heat dissipation for the cell  21 . 
     In some embodiments, the third connecting portions  621  and the fourth connecting portions  622  may be connected to the first housing  13  to transfer heat to the first housing  13 , further improving heat dissipation for the battery module  100 . 
     In an embodiment, the first connecting member  40  and the second connecting member  60  are integrally formed through bending to enhance structural strength of the first connecting member  40  and the second connecting member  60 . Optionally, the first connecting member  40  and the second connecting member  60  are an aluminum shell. 
     Referring to  FIG.  14   , this application further provides an electric device  200  using the foregoing battery module  100 . In an embodiment, the electric device  200  in this application may be, but is not limited to, a drone, a backup power source, an electric automobile, an electric motorcycle, an electric motor bicycle, an electric tool, or a large household battery. 
     Those of ordinary skill in the art should be aware of that the foregoing embodiments are only intended to describe this application, but not to limit this application. Appropriate modifications and variations made to the foregoing embodiments without departing from the essential spirit and scope of this application all fall within the scope of this application.