Battery pack and electric device

Abstract

The embodiment of the invention provides a battery pack and an electric device. The battery pack comprises a shell, a battery core assembly and a plurality of heat conduction pieces, the shell is provided with a top wall and a bottom wall which are oppositely arranged in the first direction. The battery cell assembly is arranged in the shell and comprises a plurality of battery cells arranged along a first direction; each heat conducting piece comprises a heat conducting part and a connecting part connected to the heat conducting part, each heat conducting part is located between different adjacent battery cells, the heat conducting part is connected with at least one battery cell, and the connecting part is connected with the top wall or the bottom wall.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery pack and an electrical device. Background Art

[0002] The battery pack mainly includes a shell and a battery cell assembly inside the shell. During the charging and discharging process, the battery cell assembly generates heat, which is transferred to the shell for heat dissipation. The heat generated by the battery cell assembly is not easily transferred to the shell, resulting in heat accumulation in the middle of the battery cell assembly, affecting the safety of the battery pack. Summary of the invention

[0003] The embodiments of the present invention provide a battery pack and an electric device, which can improve the safety of the battery pack.

[0004] In a first aspect, an embodiment of the present invention provides a battery pack, comprising a housing, a battery cell assembly, and a plurality of heat-conducting members. The housing has a top wall and a bottom wall arranged opposite to each other along a first direction; the battery cell assembly is arranged inside the housing, and the battery cell assembly comprises a plurality of battery cells arranged along the first direction; each heat-conducting member comprises a heat-conducting portion and a connecting portion connected to the heat-conducting portion, each heat-conducting portion is located between different adjacent battery cells, and the heat-conducting portion is connected to at least one of the battery cells, and the connecting portion is connected to the top wall or the bottom wall.

[0005] In the above embodiments, each heat conducting portion is connected to a different battery cell, and the heat conducting portion is bonded and fixed to the corresponding battery cell.

[0006] In one or more of the above optional embodiments, the battery cell assembly is provided with N battery cells, the N battery cells include a first battery cell closest to the top wall and an Nth battery cell closest to the bottom wall, the first battery cell is connected to the top wall, and the Nth battery cell is connected to the bottom wall; there are N-2 heat conductive parts, and each battery cell located between the first battery cell and the Nth battery cell is connected to a heat conductive part; N is a positive integer greater than 2.

[0007] In one or more of the above optional embodiments, the heat conductor includes an extension portion, which is located on one side of the battery cell assembly along the second direction; at least two extension portions are located on the same side of the battery cell assembly along the second direction, and the projections of the at least two extension portions along the third direction are separated; the first direction, the second direction, and the third direction are perpendicular to each other.

[0008] In one or more of the above optional embodiments, each extension portion is separated from or in direct contact with each battery cell.

[0009] In one or more of the above optional embodiments, the battery cell assembly includes a fixing member, which surrounds the multiple battery cells along the first direction and the second direction, and fixes the multiple battery cells; along the first direction, the projection of the fixing member and the projection of each heat conductor are separated; the battery cell includes an electrode terminal, and the electrode terminal is located on one side of the battery cell assembly along the third direction.

[0010] In one or more of the above optional embodiments, at least two connection portions are located on the same side of the battery cell assembly along the first direction, and projections of the at least two connection portions along the first direction are separated.

[0011] In one or more optional embodiments above, the battery pack includes a first heat transfer element, which is disposed between the top wall and the battery cell assembly and connected to the first battery cell; the thermal conductivity of the first heat transfer element is greater than or equal to 1w / (mk).

[0012] In one or more of the above optional embodiments, the thermal conductivity of the first heat transfer element at 25° C. is less than or equal to 10 w / (mk).

[0013] In one or more optional embodiments above, the first heat transfer member is connected to a portion of the first connection portion, and the first heat transfer member connects the first connection portion and the first heat sink. The first heat sink is exposed outside the battery pack, and the first heat transfer member can reduce the force on the first heat sink and transfer it to the first connection portion.

[0014] In one or more of the above optional embodiments, the first heat conductive member is a graphite heat conductive member, and the first heat conductive member can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0015] In one or more optional embodiments above, the first heat transfer member is compressed, and the first heat transfer member abuts between the first connecting portion and the first heat sink. Optionally, the first heat transfer member includes a silicone thermal pad.

[0016] In one or more optional embodiments above, the first heat transfer member is connected to a portion of the fourth connection portion, and the first heat transfer member is connected to the fourth connection portion and the first heat sink. The first heat sink is exposed outside the battery pack, and the first heat transfer member can reduce the force received by the first heat sink and transfer it to the fourth connection portion.

[0017] In one or more of the above optional embodiments, the fourth heat conducting member is a graphite heat conducting member, and the first heat conducting member can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0018] In one or more optional embodiments above, the first heat transfer member is compressed, and the first heat transfer member abuts between the four connecting parts and the first heat sink. Optionally, the first heat transfer member includes a silicone thermal pad.

[0019] In one or more optional embodiments above, the battery pack includes a second heat transfer element, which is disposed between the bottom wall and the battery cell assembly, and is connected to the Nth battery cell; the thermal conductivity of the second heat transfer element is greater than or equal to 1w / (mk).

[0020] In one or more of the above optional embodiments, the thermal conductivity of the second heat transfer element at 25° C. is less than or equal to 10 w / (mk).

[0021] In one or more of the above optional embodiments, the second heat transfer element includes but is not limited to a silicone thermal pad.

[0022] In one or more optional embodiments above, the second heat transfer member is connected to a portion of the second connection portion, and the second heat transfer member is connected to the second connection portion and the second heat sink. The second heat sink is exposed outside the battery pack, and the second heat transfer member can reduce the force on the second heat sink and transfer it to the second connection portion.

[0023] In one or more of the above optional embodiments, the second heat conductive member is a graphite heat conductive member, and the second heat conductive member can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0024] In one or more optional embodiments above, the second heat transfer member is compressed, and the second heat transfer member abuts between the second connecting portion and the second heat sink. Optionally, the second heat transfer member includes a silicone thermal pad.

[0025] In one or more optional embodiments above, the second heat transfer member is connected to a portion of the third connection portion, and the second heat transfer member is connected to the third connection portion and the second heat sink. The second heat sink is exposed outside the battery pack, and the second heat transfer member can reduce the force received by the second heat sink and transfer it to the third connection portion.

[0026] In one or more of the above optional embodiments, the third heat conducting member is a graphite heat conducting member, and the second heat conducting member can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0027] In one or more optional embodiments above, the second heat transfer member is compressed, and the second heat transfer member abuts between the third connection portion and the second heat sink. Optionally, the second heat transfer member includes a silicone thermal pad.

[0028] In one or more of the above optional embodiments, the battery pack includes a heating element, the heating element includes multiple heating parts and multiple connecting parts, the connecting part connects two adjacent heating parts; each heating part is arranged between two different adjacent battery cells, and the heating part is connected to at least one battery cell, and the connecting part is arranged on one side of the battery cell assembly along the second direction.

[0029] In one or more optional embodiments above, the heating element includes a heating wire, both sides of the heating wire are covered with an insulating film, and the thermal conductivity of the insulating film at 25°C is greater than or equal to 0.1w / (mk) and less than or equal to 0.2w / (mk).

[0030] In one or more of the above optional embodiments, the heating element includes N-2 heating parts, the battery cell assembly includes N-3 buffer parts, each buffer part is located between different adjacent battery cells; the buffer part is configured to provide expansion space for the battery cell, and the thermal conductivity of the buffer part is less than 0.5w / (mk) at 25°C; each heat-conducting part is connected to an adjacent battery cell, and the heat-conducting part is spaced apart from another adjacent battery cell through the heating part or the buffer part, or the heat-conducting part is physically separated from another adjacent battery cell.

[0031] In one or more optional embodiments above, the heat conductor is a graphite heat conductor, which is bent along its length direction to form a heat conducting portion and a connecting portion; along the length direction of the graphite heat conductor, the planar thermal conductivity of the graphite heat conductor is greater than or equal to 800w / (mk).

[0032] In one or more of the above optional embodiments, along the thickness direction of the graphite heat conductive member, the thermal conductivity of the graphite heat conductive member is less than or equal to 100 w / (mk).

[0033] In a second aspect, an embodiment of the present invention provides an electrical device, comprising a battery pack as described in the first aspect, wherein the battery pack is used to provide electrical energy.

[0034] The battery pack provided in the embodiment of the present application is provided with a heat-conducting member, a heat-conducting portion is disposed between two adjacent battery cells, and a connecting portion is connected to the top wall or the bottom wall of the outer shell. The connecting portion can transfer the heat generated in the middle position of the battery cell assembly to the outer shell during the charging and discharging process of each battery cell, thereby effectively reducing the accumulation of heat in the middle position of the battery cell assembly and improving the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0036] Figure 1 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application;

[0037] Figure 2 An exploded view of a battery pack provided for some embodiments of the present application;

[0038] Figure 3 A schematic diagram of the structure of a cell assembly of a battery pack provided in some embodiments of the present application;

[0039] Figure 4 Another schematic diagram of the structure of a cell assembly of a battery pack provided in some embodiments of the present application;

[0040] Figure 5Another structural schematic diagram of a cell assembly of a battery pack provided in some embodiments of the present application;

[0041] Figure 6 A schematic diagram of the structure of a heat conducting member of a battery pack provided in some embodiments of the present application;

[0042] Figure 7 An exploded view of a cell assembly of a battery pack provided in some embodiments of the present application;

[0043] Figure 8 A schematic structural diagram of a first heat-conducting member of a battery pack provided in some embodiments of the present application;

[0044] Fig. 9 A schematic diagram of the structure of a second heat conducting member of a battery pack provided in some embodiments of the present application;

[0045] Fig.10 A schematic structural diagram of a third heat-conducting member of a battery pack provided in some embodiments of the present application;

[0046] Fig.11 A schematic structural diagram of a fourth heat conducting member of a battery pack provided in some embodiments of the present application;

[0047] Fig.12 A schematic diagram of the structure of a heat conducting member of a battery pack provided in some embodiments of the present application when unfolded;

[0048] Fig.13 for Fig.12 Schematic diagram of the local structure;

[0049] Fig.14 A schematic diagram of the partial structure of a heating element of a battery pack provided in some embodiments of the present application.

[0050] Description of Figure Numbers:

[0051] 1. housing; 11. shell; 111. top wall; 112. bottom wall; 113. first opening; 114. second opening; 12. shell cover; 131. first radiator; 132. second radiator;

[0052] 2. Cell assembly; 21. Cell; 21a. Electrode terminal; 211. First cell; 212. Second cell; 213. Third cell; 214. Fourth cell; 215. Fifth cell; 216. Sixth cell;

[0053] 3. heat conducting member; 31. heat conducting portion; 32. extension portion; 33. connection portion; 34. graphite layer; 35. insulation layer; 36. bonding layer;

[0054] 3a, first heat conducting member; 31a, first heat conducting portion; 32a, first extending portion; 33a, first connecting portion; 34a, first bending portion; 35a, second bending portion;

[0055] 3b, second heat conducting member; 31b, second heat conducting portion; 32b, second extending portion; 33b, second connecting portion; 34b, third bending portion; 35b, fourth bending portion;

[0056] 3c, third heat conducting member; 31c, third heat conducting portion; 32c, third extending portion; 33c, third connecting portion; 34c, fifth bending portion; 35c, sixth bending portion;

[0057] 3d, fourth heat conducting member; 31d, fourth heat conducting portion; 32d, fourth extending portion; 33d, fourth connecting portion; 34d, seventh bending portion; 35d, eighth bending portion;

[0058] 41. a first heat transfer element; 42. a second heat transfer element;

[0059] 5. Buffer; 51. First buffer; 52. Second buffer;

[0060] 6. Fixing parts;

[0061] 7. Heating element; 71. Heating part; 71a. First heating part; 71b. Second heating part; 71c. Third heating part; 71d. Fourth heating part; 72. Connecting part; 72a. First connecting part; 72b. Second connecting part; 72c. Third connecting part; 73. Heating wire; 74. Insulating film; 75. Adhesive layer;

[0062] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0063] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, rather than to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0064] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0065] The battery pack and the electrical device of the present application are described below with reference to the accompanying drawings.

[0066] It should be noted that the words first direction X, second direction Y and third direction Z, which are recorded in the embodiments of the present application, are only used to more clearly illustrate the structure of the present application in conjunction with the drawings, and the present application is not limited thereto. The first direction X, the second direction Y and the third direction Z have an angle between each other. Optionally, the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0067] like Figures 1 to 7 As shown, an embodiment of the present application provides a battery pack, including a housing 1 and a battery cell assembly 2, wherein the battery cell assembly 2 is disposed inside the housing 1, and the battery cell assembly 2 includes a plurality of battery cells 21 arranged along a first direction X, and electric energy is provided by the battery cells 21. Heat inside the housing 1 is transferred to the outside of the housing 1 to cool the battery pack.

[0068] In some embodiments, the battery pack includes a plurality of heat-conducting members 3, each heat-conducting member 3 includes a heat-conducting portion 31 and a connecting portion 33, each heat-conducting portion 31 is located between different adjacent battery cells 21, and the heat-conducting portion 31 is connected to at least one of the adjacent battery cells 21, and the heat generated during the charging and discharging process of the battery cell 21 is absorbed by the heat-conducting portion 31. The connecting portion 33 is connected to the heat-conducting portion 31, and the heat absorbed by the heat-conducting portion 31 is transferred to the connecting portion 33.

[0069] In some embodiments, the housing 11 includes a top wall 111 and a bottom wall 112 that are relatively arranged along the first direction X. The connecting portion 33 is located between the battery cell assembly 2 and the top wall 111, and the connecting portion 33 is connected to the top wall 111; or the connecting portion 33 is located between the battery cell assembly 2 and the bottom wall 112, and the connecting portion 33 is connected to the bottom wall 112. The heat absorbed by the heat conducting portion 31 is dissipated to the outside of the housing 1 through the top wall 111 or the bottom wall 112, thereby achieving a cooling effect.

[0070] The multiple connection parts 33 are arranged at intervals from each other, so that each heat-conducting member 3 forms an independent heat dissipation path, which is beneficial to the heat dissipation.

[0071] The battery pack provided in the embodiment of the present application is provided with a heat-conducting member 3, a heat-conducting portion 31 is disposed between two adjacent battery cells 21, and a connecting portion 33 is connected to the top wall 111 or the bottom wall 112 of the outer shell 1. The connecting portion 33 can transfer the heat generated in the middle position of the battery cell assembly 2 to the outer shell 1 during the charging and discharging process of each battery cell 21, thereby effectively reducing the accumulation of heat in the middle position of the battery cell assembly 2 and improving the safety of the battery pack.

[0072] In some embodiments, the housing 1 includes a shell 11 and a shell cover 12 , and the shell cover 12 and the shell 11 are connected along a third direction Z to enclose and form a closed cavity, and the battery cell assembly 2 is disposed inside the cavity.

[0073] In some embodiments, optionally, the shell 11 is an integrally formed structure to enhance the structural strength and sealing of the shell 11 ; the shell cover 12 is detachably and hermetically connected to the shell 11 .

[0074] In some embodiments, the connection method includes direct contact between the two components, or bonding, such as bonding by double-sided tape.

[0075] In some embodiments, Figure 1 As shown, the housing 1 includes a first heat sink 131 , a first opening 113 is provided on the top wall 111 , the first heat sink 131 is provided at the first opening 113 , and the connecting portion 33 is connected to the first heat sink 131 .

[0076] In some embodiments, the first heat sink 131 is integrally formed and connected to the top wall 111 .

[0077] In some embodiments, the surface of the first heat sink 131 facing the battery cell assembly 2 is flush with the inner surface of the top wall 111, or the surface of the first heat sink 131 facing the battery cell assembly 2 protrudes from the inner surface of the top wall 111, and the battery cell assembly 2 and the first heat sink 131 are reliably abutted, thereby clamping the connecting portion 33 between the first heat sink 131 and the battery cell assembly 2, so that the connecting portion 33 abuts against the first heat sink 131, and the connecting portion 33 is in direct contact with the first heat sink 131, thereby improving the heat conduction efficiency of the thermal conductor 3.

[0078] In some embodiments, Figure 2 As shown, the housing 1 includes a second heat sink 132 , a second opening 114 is provided on the bottom wall 112 , the second heat sink 132 is provided at the second opening 114 , and the connecting portion 33 is connected to the second heat sink 132 .

[0079] In some embodiments, the second heat sink 132 is integrally formed and connected to the bottom wall 112 .

[0080] In some embodiments, the surface of the second heat sink 132 facing the battery cell assembly 2 is flush with the inner surface of the bottom wall 112, or the surface of the second heat sink 132 facing the battery cell assembly 2 protrudes from the inner surface of the bottom wall 112, and the battery cell assembly 2 and the second heat sink 132 are reliably abutted, thereby clamping the connecting portion 33 between the second heat sink 132 and the battery cell assembly 2, so that the connecting portion 33 abuts against the second heat sink 132, and the connecting portion 33 is in direct contact with the second heat sink 132, thereby improving the heat conduction efficiency of the thermal conductor 3.

[0081] In some embodiments, each heat conducting portion 31 is respectively connected to a different battery cell 21 to conduct heat generated by the different battery cells 21 and to achieve heat dissipation of each battery cell 21 .

[0082] In some embodiments, the heat conducting portion 31 is bonded and fixed to the corresponding battery core 21 , and the position of the heat conducting portion 31 is maintained so that the heat conducting portion 31 is reliably connected to the corresponding battery core 21 .

[0083] In some embodiments, Figures 2 to 5 and Figure 7 As shown, the battery cell assembly 2 is provided with N battery cells 21, the N battery cells 21 include a first battery cell 211 closest to the top wall 111 and an Nth battery cell 21 closest to the bottom wall 112, the first battery cell 211 is connected to the top wall 111, the heat generated by the first battery cell 211 is transferred to the top wall 111, the Nth battery cell 21 is connected to the bottom wall 112, and the heat generated by the Nth battery cell 21 is transferred to the bottom wall 112. Wherein, N is a positive integer greater than 2.

[0084] In some embodiments, N-2 heat conducting members 3 are provided, and each battery cell 21 between the first battery cell 211 and the Nth battery cell 21 is connected to a heat conducting member 31, so that the heat generated by each battery cell 21 between the first battery cell 211 and the Nth battery cell 21 is transferred to the top wall 111 or the bottom wall 112 through a heat conducting member 3 for output. Wherein, N is a positive integer greater than 2.

[0085] In some embodiments, Figures 3 to 7 As shown, the heat conducting member 3 includes an extension portion 32. The extension portion 32 is used to achieve heat conduction between the heat conducting portion 31 and the connecting portion 33. The extension portion 32 is located on one side of the battery core assembly 2 along the second direction Y.

[0086] In some embodiments, the heat conducting portion 31 , the extension portion 32 , and the connection portion 33 are integrally formed and connected to form a complete sheet structure. The heat conducting portion 31 , the extension portion 32 , and the connection portion 33 are all formed by bending the heat conducting member 3 .

[0087] In some embodiments, at least two extension portions 32 are located on the same side of the battery cell assembly 2 along the second direction Y, and the projections of the at least two extension portions 32 along the third direction Z are separated to form independent heat dissipation paths, reduce heat accumulation, and improve heat transfer efficiency.

[0088] In some embodiments, the extension portion 32 is separated from or in direct contact with each battery cell 21; the extension portion 32 is not fixed to the battery cell assembly 2, and when the battery cell assembly 2 expands and changes in size along the first direction X, the pulling force on the extension portion 32 can be reduced, thereby providing protection for the extension portion 32.

[0089] In some embodiments, Figure 2 and Figure 3 As shown, each battery cell 21 includes an electrode terminal 21a, and the electrical connection of the battery cell 21 is achieved through the electrode terminal 21a. The electrode terminal 21a is located on one side of the battery cell 21 along the third direction Z; the heat conductive member 3 and the electrode terminal 21a are arranged in different directions of the battery cell 21, reducing the interference between the electrode terminal 21a and the heat conductive member 3.

[0090] In some embodiments, at least two connecting portions 33 are located on the same side of the battery cell assembly 2 along the first direction X, and the projections of the at least two connecting portions 33 along the first direction X are separated, and there is no contact between the connecting portions 33, so as to form independent heat dissipation paths respectively, reduce heat accumulation, and improve heat transfer efficiency.

[0091] In some embodiments, along the first direction X, the length of the extension portion 32 is greater than the distance between the connection portion 33 and the heat conduction portion 31 to form a redundant space. When the battery cell assembly 2 expands along the first direction X, the extension portion 32 can be less likely to be pulled and damaged.

[0092] In some embodiments, Figures 2 to 5 and Figure 7 As shown, the battery cell assembly 2 includes six battery cells 21 for illustration, that is, N is equal to 6.

[0093] The battery cell 21 includes a first battery cell 211 , a second battery cell 212 , a third battery cell 213 , a fourth battery cell 214 , a fifth battery cell 215 and a sixth battery cell 216 arranged along the first direction X.

[0094] The heat conducting member 3 includes a first heat conducting member 3a, a second heat conducting member 3b, a third heat conducting member 3c and a fourth heat conducting member 3d.

[0095] In some embodiments, Figure 8As shown, the first heat-conducting member 3a includes a first heat-conducting portion 31a, a first extension portion 32a and a first connecting portion 33a. The first extension portion 32a is used to achieve heat conduction between the first heat-conducting portion 31a and the first connecting portion 33a. The first heat-conducting portion 31a is located between the second battery cell 212 and the third battery cell 213, and the first heat-conducting portion 31a is connected to the second battery cell 212, and the heat generated during the charging and discharging process of the second battery cell 212 is transferred through the first heat-conducting portion 31a.

[0096] In some embodiments, the first heat conducting portion 31 a and the second battery core 212 are bonded to maintain the position of the first heat conducting portion 31 a, so that the connection between the first heat conducting portion 31 a and the second battery core 212 is more reliable.

[0097] In some embodiments, the first heat conducting portion 31a, the first extension portion 32a and the first connecting portion 33a are integrally formed and connected to form a complete sheet structure, and the first heat conducting portion 31a, the first extension portion 32a and the first connecting portion 33a are all formed by bending the first heat conducting member 3a.

[0098] In some embodiments, the first connection portion 33a is located between the top wall 111 and the first battery cell 211, and the first connection portion 33a is connected to the top wall 111. The heat absorbed by the first heat conducting portion 31a is transferred to the top wall 111 through the first connection portion 33a, and dissipated through the top wall 111, thereby achieving a cooling effect.

[0099] In some embodiments, the first connection portion 33 a is bonded to the first battery cell 211 , and the position of the first connection portion 33 a is maintained, so that the first connection portion 33 a is reliably connected to the top wall 111 .

[0100] In some embodiments, the first extension portion 32a is located on one side of the battery cell assembly 2 along the second direction Y, and the first extension portion 32a is separated from or in direct contact with the first battery cell 211 and the second battery cell 212; the first extension portion 32a is not fixed to the first battery cell 211 and the second battery cell 212, and when the first battery cell 211 or the second battery cell 212 expands and changes in size along the first direction X, the pulling force on the first extension portion 32a can be reduced, thereby providing protection for the first extension portion 32a.

[0101] In some embodiments, the length of the first extension portion 32a is greater than the distance between the first connection portion 33a and the first heat conducting portion 31a along the first direction X to form a redundant space. When the battery cell assembly 2 expands along the first direction X, the first extension portion 32a can be reduced from being pulled and damaged.

[0102] In some embodiments, a first bending portion 34a is connected between the first extension portion 32a and the first heat conducting portion 31a, and a second bending portion 35a is connected between the first extension portion 32a and the first connecting portion 33a. When the battery cell assembly 2 expands along the first direction X, the first bending portion 34a and the second bending portion 35a can be deformed to reduce the damage to the first extension portion 32a caused by pulling.

[0103] In some embodiments, Fig. 9 As shown, the second heat-conducting member 3b includes a second heat-conducting portion 31b, a second extension portion 32b and a second connecting portion 33b. The second extension portion 32b is used to achieve heat conduction between the second heat-conducting portion 31b and the second connecting portion 33b. The second heat-conducting portion 31b is located between the third battery cell 213 and the fourth battery cell 214, and the second heat-conducting portion 31b is connected to the third battery cell 213, and the heat generated during the charging and discharging process of the third battery cell 213 is transferred through the second heat-conducting portion 31b.

[0104] In some embodiments, the second heat conducting portion 31 b is bonded to the third battery core 213 to maintain the position of the second heat conducting portion 31 b , so that the second connecting portion 33 b is more reliably connected to the top wall 111 .

[0105] In some embodiments, the second heat conducting portion 31b, the second extension portion 32b and the second connecting portion 33b are integrally formed and connected to form a complete sheet structure, and the second heat conducting portion 31b, the second extension portion 32b and the second connecting portion 33b are all formed by bending the second heat conducting member 3b.

[0106] In some embodiments, the second connection portion 33b is located between the top wall 111 and the first battery cell 211, the second connection portion 33b is connected to the top wall 111, and the heat absorbed by the second heat conducting portion 31b is transferred to the top wall 111 through the second connection portion 33b, and dissipated through the top wall 111, thereby achieving a cooling effect.

[0107] In some embodiments, the second connection portion 33 b is bonded to the first battery cell 211 , and the position of the second connection portion 33 b is maintained, so that the second connection portion 33 b is connected to the top wall 111 at a higher level.

[0108] In some embodiments, the second extension portion 32b is located on one side of the battery cell assembly 2 along the second direction Y, and the second extension portion 32b is separated from or in direct contact with the first battery cell 211, the second battery cell 212 and the third battery cell 213; the second extension portion 32b is not fixed to the first battery cell 211, the second battery cell 212 and the third battery cell 213, and when the first battery cell 211, the second battery cell 212 and the third battery cell 213 expand and change their dimensions along the first direction X, the pulling force on the second extension portion 32b can be reduced, thereby providing protection for the second extension portion 32b.

[0109] In some embodiments, the first extension portion 32a and the second extension portion 32b are disposed oppositely on two sides of the battery cell assembly 2 along the second direction Y. The heat generated by the second battery cell 212 and the third battery cell 213 is conducted and dissipated through different paths, which can improve the heat dissipation efficiency of the battery pack.

[0110] In some embodiments, along the first direction X, the projection of the first connection portion 33 a and the projection of the second connection portion 33 b are separated, and the heat generated by the second battery cell 212 and the third battery cell 213 is dissipated through different paths, thereby improving the heat dissipation efficiency of the battery pack.

[0111] In some embodiments, the length of the second extension portion 32b is greater than the distance between the second connection portion 33b and the second heat conducting portion 31b along the first direction X to form a redundant space. When the battery cell assembly 2 expands along the first direction X, the second extension portion 32b can be reduced from being pulled and damaged.

[0112] In some embodiments, a third bent portion 34b is connected between the second extension portion 32b and the second heat conducting portion 31b, and a fourth bent portion 35b is connected between the first extension portion 32a and the first connecting portion 33a. When the battery cell assembly 2 expands along the first direction X, the third bent portion 34b and the fourth bent portion 35b can be deformed to reduce the damage to the second extension portion 32b caused by pulling.

[0113] In some embodiments, Fig.10 As shown, the third heat conducting member 3c includes a third heat conducting portion 31c, a third extension portion 32c and a third connecting portion 33c. The third extension portion 32c is used to achieve heat conduction between the third heat conducting portion 31c and the third connecting portion 33c. The third heat conducting portion 31c is located between the third battery cell 213 and the fourth battery cell 214, and the third heat conducting portion 31c is connected to the fourth battery cell 214, and the heat generated during the charging and discharging process of the fourth battery cell 214 is transferred through the third heat conducting portion 31c.

[0114] In some embodiments, the third heat conducting portion 31 c and the fourth battery core 214 are bonded to maintain the position of the third heat conducting portion 31 c, so that the connection between the third heat conducting portion 31 c and the fourth battery core 214 is more reliable.

[0115] In some embodiments, the third heat conducting portion 31c, the third extension portion 32c and the third connecting portion 33c are integrally formed and connected to form a complete sheet structure, and the third heat conducting portion 31c, the third extension portion 32c and the third connecting portion 33c are all formed by bending the third heat conducting member 3c.

[0116] In some embodiments, the third connection portion 33c is located between the bottom wall 112 and the sixth battery cell 216, and the heat absorbed by the third heat conducting portion 31c is transferred to the bottom wall 112 through the third connection portion 33c, and dissipated through the bottom wall 112 to achieve a cooling effect.

[0117] In some embodiments, the third connection portion 33 c is bonded to the sixth battery cell 216 to maintain the position of the third connection portion 33 c, so that the connection between the third connection portion 33 c and the bottom wall 112 is more reliable.

[0118] In some embodiments, the third extension portion 32c is located on one side of the battery cell assembly 2 along the second direction Y, and the third extension portion 32c is separated from or in direct contact with the fourth battery cell 214, the fifth battery cell 215 and the sixth battery cell 216; the third extension portion 32c is not fixed to the fourth battery cell 214, the fifth battery cell 215 and the sixth battery cell 216, and when the fourth battery cell 214, the fifth battery cell 215 and the sixth battery cell 216 expand and change in size along the first direction X, the pulling force on the third extension portion 32c can be reduced, thereby providing protection for the third extension portion 32c.

[0119] In some embodiments, the third extension portion 32c and the second extension portion 32b are disposed on the same side of the battery cell assembly 2 along the second direction Y, and the projection of the third extension portion 32c is separated from the projection of the second extension portion 32b along the second direction Y. The heat generated by the fourth battery cell 214 and the third battery cell 213 is conducted and dissipated through different paths, which can improve the heat dissipation efficiency of the battery pack.

[0120] In some embodiments, the length of the third extension portion 32c is greater than the distance between the third connection portion 33c and the third heat conducting portion 31c along the first direction X to form a redundant space. When the battery cell assembly 2 expands along the first direction X, the third extension portion 32c can be reduced from being pulled and damaged.

[0121] In some embodiments, a fifth bending portion 34c is connected between the third extension portion 32c and the third heat conducting portion 31c, and a sixth bending portion 35c is connected between the third extension portion 32c and the third connecting portion 33c. When the battery cell assembly 2 expands along the first direction X, the fifth bending portion 34c and the sixth bending portion 35c can be deformed to reduce the damage of the third extension portion 32c caused by pulling.

[0122] In some embodiments, Fig.11As shown, the fourth heat-conducting member 3d includes a fourth heat-conducting portion 31d, a fourth extension portion 32d and a fourth connection portion 33d. The fourth extension portion 32d is used to conduct heat between the fourth heat-conducting portion 31d and the fourth connection portion 33d. The fourth heat-conducting portion 31d is located between the fourth battery cell 214 and the fifth battery cell 215, and the fourth heat-conducting portion 31d is connected to the fifth battery cell 215. The heat generated during the charging and discharging process of the fifth battery cell 215 is absorbed by the fourth heat-conducting portion 31d.

[0123] In some embodiments, the fourth heat conducting portion 31 d and the fifth battery cell 215 are bonded to maintain the position of the fourth heat conducting portion 31 d , so that the connection between the fourth heat conducting portion 31 d and the fifth battery cell 215 is more reliable.

[0124] In some embodiments, the fourth heat conducting portion 31d, the fourth extension portion 32d and the fourth connecting portion 33d are integrally formed and connected to form a complete sheet structure, and the fourth heat conducting portion 31d, the fourth extension portion 32d and the fourth connecting portion 33d are all formed by bending the fourth heat conducting member 3d.

[0125] In some embodiments, the fourth connection portion 33d is located between the bottom wall 112 and the sixth battery cell 216, and the heat absorbed by the fourth heat conducting portion 31d is transferred to the bottom wall 112 through the fourth connection portion 33d, and dissipated through the bottom wall 112 to achieve a cooling effect.

[0126] In some embodiments, the fourth connection portion 33 d and the sixth battery cell 216 are bonded to maintain the position of the fourth connection portion 33 d so that the fourth connection portion 33 d is reliably connected to the bottom wall 112 .

[0127] In some embodiments, the fourth extension portion 32d is located on one side of the battery cell assembly 2 along the second direction Y, and the fourth extension portion 32d is separated from or in direct contact with the fifth battery cell 215 and the sixth battery cell 216; the fourth extension portion 32d is not fixed to the fifth battery cell 215 and the sixth battery cell 216, and when the fifth battery cell 215 and the sixth battery cell 216 expand and change in size along the first direction X, the pulling force on the fourth extension portion 32d can be reduced, thereby providing protection for the fourth extension portion 32d.

[0128] In some embodiments, the fourth extension portion 32d and the first extension portion 32a are disposed on the same side of the battery cell assembly 2 along the second direction Y, and the projection of the fourth extension portion 32d is separated from the projection of the first extension portion 32a along the second direction Y. The heat generated by the fifth battery cell 215 and the first battery cell 211 is conducted and dissipated through different paths, which can improve the heat dissipation efficiency of the battery pack.

[0129] In some embodiments, along the first direction X, the projection of the third connection portion 33 c and the projection of the fourth connection portion 33 d are separated, and the heat generated by the fifth battery cell 215 and the fourth battery cell 214 is conducted and dissipated through different paths, which can improve the heat dissipation efficiency of the battery pack.

[0130] In some embodiments, the length of the fourth extension portion 32d is greater than the distance between the fourth connection portion 33d and the fourth heat conducting portion 31d along the first direction X to form a redundant space. When the battery cell assembly 2 expands along the first direction X, the fourth extension portion 32d can be reduced from being pulled and damaged.

[0131] In some embodiments, a seventh bent portion 34d is connected between the fourth extension portion 32d and the fourth heat conducting portion 31d, and an eighth bent portion 35d is connected between the fourth extension portion 32d and the fourth connecting portion 33d. When the battery cell assembly 2 expands along the first direction X, the seventh bent portion 34d and the eighth bent portion 35d can be deformed to reduce the damage of the fourth extension portion 32d caused by pulling.

[0132] In some embodiments, Figures 2 to 4 As shown, the battery pack includes a first heat transfer member 41 , which is disposed between the top wall 111 and the battery cell assembly 2 . The first heat transfer member 41 is configured to transfer heat from the first battery cell 211 to the top wall 111 to dissipate heat from the first battery cell 211 .

[0133] In some embodiments, the thermal conductivity of the first heat transfer element 41 at 25° C. is greater than or equal to 1 w / (mk), which is beneficial to heat conduction.

[0134] In some embodiments, the thermal conductivity of the first heat transfer element 41 at 25° C. is less than or equal to 10 w / (mk). The first heat transfer element 41 includes but is not limited to a silicone thermal pad.

[0135] In some embodiments, the first heat transfer member 41 is connected to a portion of the first connection portion 33a, and the first heat transfer member 41 connects the first connection portion 33a and the first heat sink 131. The first heat sink 131 is exposed outside the battery pack, and the first heat transfer member 41 can reduce the force on the first heat sink 131 and transfer it to the first connection portion 33a.

[0136] In some embodiments, the first heat conducting member 3a is a graphite heat conducting member, and the first heat conducting member 41 can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0137] In some embodiments, the first heat transfer member 41 is compressed, and the first heat transfer member 41 abuts between the first connection portion 33a and the first heat sink 131. Optionally, the first heat transfer member 41 includes a silicone thermal pad.

[0138] In some embodiments, the first heat transfer member 41 is connected to a portion of the fourth connection portion 33d, and the first heat transfer member 41 connects the fourth connection portion 33d and the first heat sink 131. The first heat sink 131 is exposed to the outside of the battery pack, and the first heat transfer member 41 can reduce the force on the first heat sink 131 and transfer it to the fourth connection portion 33d.

[0139] In some embodiments, the fourth heat conducting member 3d is a graphite heat conducting member, and the first heat conducting member 41 can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0140] In some embodiments, the first heat transfer member 41 is compressed, and the first heat transfer member 41 abuts between the fourth connecting portion 33d and the first heat sink 131. Optionally, the first heat transfer member 41 includes a silica gel thermal pad.

[0141] In some embodiments, the battery pack includes a second heat transfer member 42, which is disposed between the bottom wall 112 and the battery cell assembly 2, and the second heat transfer member 42 is configured to transfer the heat of the sixth battery cell 216 to the bottom wall 112 to dissipate heat for the sixth battery cell 216. The thermal conductivity of the second heat transfer member 42 is greater than or equal to 1w / (mk), which is conducive to heat conduction.

[0142] In some embodiments, the thermal conductivity of the second heat transfer element 42 at 25° C. is less than or equal to 10 w / (mk).

[0143] In some embodiments, the second heat transfer element 42 includes but is not limited to a silicone thermal pad.

[0144] In some embodiments, the second heat transfer member 42 is connected to a portion of the second connection portion 33b, and the second heat transfer member 42 connects the second connection portion 33b and the second heat sink 132. The second heat sink 132 is exposed outside the battery pack, and the second heat transfer member 42 can reduce the force on the second heat sink 132 and transfer it to the second connection portion 33b.

[0145] In some embodiments, the second heat conducting member 3 b is a graphite heat conducting member, and the second heat conducting member 42 can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0146] In some embodiments, the second heat transfer member 42 is compressed, and the second heat transfer member 42 abuts between the second connecting portion 33b and the second heat sink 132. Optionally, the second heat transfer member 42 includes a silica gel thermal pad.

[0147] In some embodiments, the second heat transfer member 42 is connected to a portion of the third connection portion 33c, and the second heat transfer member 42 connects the third connection portion 33c and the second heat sink 132. The second heat sink 132 is exposed outside the battery pack, and the second heat transfer member 42 can reduce the force received by the second heat sink 132 and transfer it to the third connection portion 33c.

[0148] In some embodiments, the third heat conducting member 3c is a graphite heat conducting member, and the second heat conducting member 42 can reduce the movement of graphite and thus reduce the heat transfer efficiency.

[0149] In some embodiments, the second heat transfer member 42 is compressed, and the second heat transfer member 42 abuts between the third connection portion 33c and the second heat sink 132. Optionally, the second heat transfer member 42 includes a silicone thermal pad.

[0150] In some embodiments, the structures and thermal conductivity of the first heat conducting member 3a, the second heat conducting member 3b, the third heat conducting member 3c, and the fourth heat conducting member 3d are substantially the same.

[0151] In some embodiments, the heat conducting member 3 is a graphite heat conducting member, which is bent along its length direction to form a heat conducting portion 31 and a connecting portion 33 .

[0152] In some embodiments, the planar thermal conductivity of the graphite heat conductor is greater than or equal to 800w / (mk) and less than or equal to 2000w / (mk), so that the heat conductor 3 has good thermal conductivity. Each heat conducting portion 31 is bonded and fixed to a different battery cell 21, which reduces the movement of graphite particles in the graphite layer 34 and is conducive to stabilizing the thermal conductivity of the heat conductor 3.

[0153] In some embodiments, along the thickness direction of the graphite thermal conductor, the thermal conductivity of the graphite thermal conductor is greater than or equal to 30w / (mk) and less than or equal to 100w / (mk). The graphite thermal conductor mainly conducts heat along the path in the length direction of the graphite thermal conductor, which is beneficial to enhance the heat dissipation of the battery cell 21 and reduce the temperature difference between different battery cells 21.

[0154] In some embodiments, Fig.12 and Fig.13 As shown, the heat conducting member 3 includes a graphite layer 34, which is the main component for achieving heat conduction of the heat conducting member 3. Both sides of the graphite layer 34 are covered with insulating layers 35, respectively, to reduce the risk of the graphite layer 34 affecting the circuit safety of the battery cell assembly 2 due to the circuit conduction between the battery cells 21.

[0155] Optionally, the insulating layer 35 and the graphite layer 34 are bonded and fixed by an adhesive layer 36 to improve the connection reliability between the insulating layer 35 and the graphite layer 34 .

[0156] In some embodiments, the battery pack includes a heating element 7, the heating element 7 includes a plurality of heating portions 71 and a plurality of connecting portions 72, the heating portion 71 is disposed between two different adjacent battery cells 21, and the heating portion 71 is connected to at least one battery cell 21, and each battery cell 21 is heated by the heating portion 71. The connecting portion 72 is disposed on one side of the battery cell 21 module along the second direction Y, and the connecting portion 72 connects two adjacent heating portions 71.

[0157] In some embodiments, Fig.14 As shown, the heating element 7 includes a heating wire 73, which is the main component for achieving instant heating of the heating element 7. Both sides of the heating wire 73 are covered with insulating films 74 to reduce the risk of the heating wire 73 conducting the circuit between the battery cells 21 and affecting the circuit safety of the battery cell assembly 2.

[0158] In some embodiments, the insulating film 74 and the heating wire 73 are bonded and fixed by an adhesive layer 75 to improve the connection reliability between the insulating film 74 and the heating wire 73 .

[0159] The thermal conductivity of the insulating film 74 is greater than or equal to 0.1 w / (mk) and less than or equal to 0.2 w / (mk), so that the insulating film 74 has thermal conductivity and slowly heats the battery cell 21 .

[0160] In some embodiments, the heating element 7 includes N-2 heating portions 71 , and the battery cell assembly 2 includes N-3 buffer elements 5 , each buffer element 5 being located between different adjacent battery cells 21 .

[0161] The buffer member 5 is configured to provide expansion space for the battery cell 21 , and the thermal conductivity of the buffer member 5 at 25° C. is less than 0.5 w / (mk).

[0162] Optionally, the thermal conductivity of the buffer 5 at 25°C is less than 0.05w / (mk).

[0163] In some embodiments, see Figure 4 The buffer member 5 includes a first buffer member 51 and a second buffer member 52 which are spaced apart from each other. In other embodiments, the buffer member 5 can be integrally formed.

[0164] In some embodiments, each heat conducting portion 31 is connected to an adjacent battery cell 21, and is spaced apart from another adjacent battery cell 21 by a heating portion 71 or a buffer member 5. The thermal conductivity of the heating portion 71 is smaller than that of the heat conducting portion 31, and the thermal conductivity of the buffer member 5 is smaller than that of the heat conducting portion 31, thereby reducing the heat transferred from another battery cell 21 to the heat conducting portion 31.

[0165] In some embodiments, the heat conducting portion 31 is physically separated from another adjacent battery cell 21 , and physical separation means that there is a gap between the heat conducting portion 31 and the battery cell 21 , and there is no other filling member in the gap.

[0166] In the embodiment where the battery cell assembly 2 has six battery cells 21 , the heating element 7 includes a first heating portion 71a , a second heating portion 71b , a third heating portion 71c and a fourth heating portion 71d , and the heating element 7 includes a first connecting portion 72a , a second connecting portion 72b and a third connecting portion 72c .

[0167] The first connecting portion 72a is connected between the first heating portion 71a and the second heating portion 71b, and the first connecting portion 72a is used to connect the heating circuits of the first heating portion 71a and the second heating portion 71b. The first heating portion 71a is disposed between the first battery cell 211 and the second battery cell 212, and is bonded and fixed to the first battery cell 211, and is used to heat the first battery cell 211 in a relatively low temperature environment.

[0168] In some embodiments, a buffer member 5 is located between the first battery cell 211 and the second battery cell 212 to provide expansion space for the first battery cell 211 and the second battery cell 212 .

[0169] In some embodiments, the first buffer member 51 and the second buffer member 52 are located between the first battery cell 211 and the second battery cell 212, and a gap is formed between the first battery cell 211 and the second battery cell 212. When heated, the gap can reduce the heat transfer from the first heating portion 71a to the second battery cell 212. In other embodiments, the buffer member 5 is integrally formed, and the buffer member 5 covers the first heating portion 71a, reducing the heat transfer from the first heating portion 71a to the second battery cell 212.

[0170] In some embodiments, the second connecting portion 72b is connected between the second heating portion 71b and the third heating portion 71c, and the second connecting portion 72b is used to connect the heating circuits of the second heating portion 71b and the third heating portion 71c. The second heating portion 71b is disposed between the second battery cell 212 and the third battery cell 213, and is bonded and fixed to the third battery cell 213. The second heat-conducting portion 31b is located between the second battery cell 212 and the second heating portion 71. When heating, the second heat-conducting portion 31b transfers the heat of the second heating portion 71b to the second battery cell 212, and the second heating portion 71b heats the second battery cell 212 and the third battery cell 213 at the same time. When the second heat-conducting portion 31b dissipates heat, the second heating portion 71b can limit the heat of the third battery cell 213 from being transferred to the second heat-conducting portion 31b.

[0171] In some embodiments, the second heating portion 71b may be in direct contact with the second heat conducting portion 31b.

[0172] In some embodiments, the third connection portion 72c is connected between the third heating portion 71c and the fourth heating portion 71d, and the third connection portion 72c is used to connect the heating circuits of the third heating portion 71c and the fourth heating portion 71d. The third heating portion 71c is disposed between the fourth battery cell 214 and the fifth battery cell 215, and is bonded and fixed to the fourth battery cell 214. The third heat conducting portion 31c is disposed between the fourth battery cell 214 and the fifth battery cell 215. When heating, the third heat conducting portion 31c transfers the heat of the third heating portion 71c to the fourth battery cell 214, and the third heating portion 71c heats the fourth battery cell 214 and the fifth battery cell 215.

[0173] In some embodiments, the third heating portion 71 c may be in direct contact with the third heat conducting portion 31 c .

[0174] In some embodiments, the fourth heating portion 71 d is disposed between the fifth battery cell 215 and the sixth battery cell 216 and is bonded and fixed to the sixth battery cell 216 for heating the fifth battery cell 215 in a relatively low temperature environment.

[0175] In some embodiments, a buffer 5 is located between the fifth battery cell 215 and the sixth battery cell 216 to provide expansion space for the fifth battery cell 215 and the sixth battery cell 216 .

[0176] In some embodiments, the first buffer member 51 and the second buffer member 52 are located between the fifth battery cell 215 and the sixth battery cell 216, and a gap is formed between the fifth battery cell 215 and the sixth battery cell 216. When heated, the gap can reduce the heat transfer from the fourth heating portion 71d to the fifth battery cell 215. In other embodiments, the buffer member 5 is integrally formed, and the buffer member 5 covers the fourth heating portion 71d, reducing the heat transfer from the fourth heating portion 71d to the fifth battery cell 215.

[0177] In some embodiments, a buffer member 5 is located between the third battery cell 213 and the fourth battery cell 214 to provide expansion space for the third battery cell 213 and the fourth battery cell 214 .

[0178] In some embodiments, the first buffer 51 and the second buffer 52 are located between the third battery cell 213 and the fourth battery cell 214, and a gap is formed between the third battery cell 213 and the fourth battery cell 214, and the gap can reduce heat transfer between the first heat conducting part 31a and the fourth heat conducting part 31d.

[0179] In other embodiments, the buffer member 5 is integrally formed, and the buffer member 5 covers the first heat conducting portion 31 a and the fourth heat conducting portion 31 d , thereby reducing heat transfer between the first heat conducting portion 31 a and the fourth heat conducting portion 31 d .

[0180] The first connecting portion 72a and the third connecting portion 72c are located on one side of the battery cell assembly 2 along the second direction Y, and the second connecting portion 72b is located on the other side of the battery cell assembly 2 along the second direction Y, so that the first heating portion 71a, the first connecting portion 72a, the second heating portion 71b, the second connecting portion 72b, the third heating portion 71c, the third connecting portion 72c and the fourth heating portion 71d are connected in series.

[0181] The first connecting portion 72 a is separated from or directly in contact with the second battery core 212 along the second direction Y, and the first connecting portion 72 a is separated from or directly in contact with the second extending portion 32 b along the second direction Y.

[0182] The second connecting portion 72 b is separated from or directly contacts the third battery cell 213 and the fourth battery cell 214 along the second direction Y.

[0183] The third connecting portion 72 c is separated from or directly contacts the fifth battery cell 215 along the second direction Y, and the third connecting portion 72 c is separated from or directly contacts the third extending portion 32 c along the second direction Y.

[0184] In some embodiments, Figure 2 As shown, the battery cell assembly 2 includes a fixing member 6 , which surrounds the battery cell assembly 2 along the first direction X and the second direction Y. The fixing member 6 limits each battery cell 21 and fixes the multiple battery cells 21 to form the battery cell assembly 2 .

[0185] Along the first direction X, the projection of the fixing member 6 and the projection of the first heat conducting member 3 a are separated from each other, so as to reduce the mutual interference between the fixing member 6 and the first heat conducting member 3 a and thus reduce the influence on the heat conducting efficiency of the first heat conducting member 3 a.

[0186] Along the first direction X, the projection of the fixing member 6 and the projection of the second heat conducting member 3 b are separated, so as to reduce the mutual interference between the fixing member 6 and the second heat conducting member 3 b and reduce the influence on the heat conducting efficiency of the second heat conducting member 3 b.

[0187] Along the first direction X, the projection of the fixing member 6 and the projection of the third heat-conducting member 3 c are separated from each other, so as to reduce the mutual interference between the fixing member 6 and the third heat-conducting member 3 c and reduce the influence on the heat-conducting efficiency of the third heat-conducting member 3 c.

[0188] Along the first direction X, the projection of the fixing member 6 and the projection of the fourth heat conducting member 3 d are separated from each other, so as to reduce the mutual interference between the fixing member 6 and the fourth heat conducting member 3 d and reduce the influence on the heat conduction efficiency of the fourth heat conducting member 3 d.

[0189] In some embodiments, along the first direction X, the projection of the fixing member 6 and the projection of the buffer member 5 at least partially overlap, and the buffer member 5 provides support for the fixing member 6, thereby reducing stress concentration and bending deformation of the battery cell 21 at the binding position of the fixing member 6, thereby improving the safety of the battery cell assembly 2.

[0190] An embodiment of the present application provides an electrical device, including the battery pack as described above, and the battery pack is used to provide electrical energy.

[0191] The battery pack of the electrical device provided in the embodiment of the present application is provided with a heat conducting member 3, wherein the heat conducting portion 31 is disposed between two adjacent battery cells 21, and the connecting portion 33 is connected to the top wall 111 or the bottom wall 112 of the outer shell 1. The connecting portion 33 can transfer the heat generated in the middle position of the battery cell assembly 2 to the heat sink 13 of the outer shell 1 during the charging and discharging process of each battery cell 21, and dissipate the heat through the heat sink 13, thereby effectively reducing the accumulation of heat in the middle position of the battery cell assembly 2 and improving the safety of the battery pack.

[0192] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A battery pack comprising: The housing has a top wall and a bottom wall arranged opposite to each other along a first direction; A battery cell assembly is disposed inside the housing, and the battery cell assembly includes a plurality of battery cells arranged along the first direction; A plurality of heat-conducting members, each of which comprises a heat-conducting portion and a connecting portion connected to the heat-conducting portion, each of which is located between different adjacent battery cells, and the heat-conducting portion is connected to at least one of the adjacent battery cells, and the connecting portion is connected to the top wall or the bottom wall.

2. The battery pack according to claim 1, characterized in that: Each of the heat conducting parts is connected to a different battery core, and the heat conducting part is bonded and fixed to the corresponding battery core.

3. The battery pack according to claim 1 or 2, characterized in that: The battery cell assembly is provided with N battery cells, the N battery cells include a first battery cell closest to the top wall and an Nth battery cell closest to the bottom wall, the first battery cell is connected to the top wall, and the Nth battery cell is connected to the bottom wall; The heat conducting members are provided with N-2 pieces, and each of the battery cells located between the first battery cell and the Nth battery cell is connected to one of the heat conducting parts; N is a positive integer greater than 2.

4. The battery pack according to claim 3, characterized in that: The heat conducting member comprises an extension portion, and the extension portion is located on one side of the battery core assembly along the second direction; At least two of the extension portions are located on the same side of the battery cell assembly along the second direction, and the projections of the at least two extension portions along the third direction are separated; the first direction, the second direction, and the third direction are perpendicular to each other.

5. The battery pack according to claim 4, characterized in that: Each of the extending portions is separated from or in direct contact with each of the battery cells.

6. The battery pack according to claim 4 or 5, characterized in that: The battery cell assembly includes a fixing member, the fixing member surrounds the plurality of battery cells along the first direction and the second direction, and the fixing member fixes the plurality of battery cells; along the first direction, a projection of the fixing member and a projection of each of the heat conducting members are separated; The battery cell includes an electrode terminal, and the electrode terminal is located on one side of the battery cell assembly along the third direction.

7. The battery pack according to any one of claims 4 to 6, characterized in that: At least two of the connection portions are located on the same side of the battery core assembly along the first direction, and projections of the at least two connection portions along the first direction are separated from each other.

8. The battery pack according to claim 7, characterized in that: The battery pack includes a first heat transfer member, the first heat transfer member is disposed between the top wall and the battery core assembly, and the first heat transfer member is connected to the first battery core; The thermal conductivity of the first heat transfer element is greater than or equal to 1w / (mk).

9. The battery pack according to claim 7 or 8, characterized in that: The battery pack includes a second heat transfer member, the second heat transfer member is disposed between the bottom wall and the battery cell assembly, and the second heat transfer member is connected to the Nth battery cell; The thermal conductivity of the second heat transfer element is greater than or equal to 1w / (mk).

10. The battery pack according to any one of claims 4 to 9, characterized in that: The battery pack includes a heating element, the heating element includes a plurality of heating parts and a plurality of connecting parts, and the connecting part connects two adjacent heating parts; Each of the heating parts is disposed between two different adjacent battery cells, and the heating part is connected to at least one of the battery cells, and the connecting part is disposed on one side of the battery cell assembly along the second direction.

11. The battery pack according to claim 10, characterized in that: The heating element comprises a heating wire, both sides of the heating wire are covered with an insulating film, and the thermal conductivity of the insulating film at 25° C. is greater than or equal to 0.1 w / (mk) and less than or equal to 0.2 w / (mk).

12. The battery pack according to claim 10 or 11, characterized in that: The heating element includes N-2 heating parts, and the battery cell assembly includes N-3 buffer members, each of which is located between different adjacent battery cells; The buffer is configured to provide expansion space for the battery core, and the thermal conductivity of the buffer at 25° C. is less than 0.5 w / (mk); Each of the heat conducting parts is connected to an adjacent one of the battery cells, and the heat conducting part is spaced apart from another adjacent one of the battery cells through the heating part or the buffer, or the heat conducting part is physically separated from another adjacent one of the battery cells.

13. The battery pack according to any one of claims 1 to 12, characterized in that: The heat conducting member is a graphite heat conducting member, and the graphite heat conducting member is bent along its length direction to form the heat conducting portion and the connecting portion; Along the length direction of the graphite heat conductive component, the planar thermal conductivity of the graphite heat conductive component is greater than or equal to 800w / (mk).

14. The battery pack according to claim 13, characterized in that: Along the thickness direction of the graphite heat conductive member, the thermal conductivity of the graphite heat conductive member is less than or equal to 100w / (mk).

15. An electrical device, characterized in that: The electrical device comprises a battery pack as claimed in any one of claims 1 to 14, wherein the battery pack is used to provide electrical energy.

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