Battery cell, battery and electric equipment

Abstract

The utility model provides a battery cell, a battery and electric equipment, the battery cell comprises a battery cell body, a first heat conduction film layer and a second heat conduction film layer, the battery cell body comprises two end faces opposite in a first direction and two first side faces opposite in a second direction, each end face is provided with a pole, at least one first side face is used for being connected with a cold plate, and the second heat conduction film layer is used for being connected with the cold plate. Each first side face comprises two first areas and a second area located between the two first areas in the first direction, and the two first areas are close to the two end faces respectively; the first heat-conducting film layer is positioned on the first area of at least one first side surface; the second heat conduction film layer is located on the second area of the at least one first side face, the heat conductivity coefficient of the first heat conduction film layer is larger than that of the second heat conduction film layer, and the first direction is perpendicular to the second direction. The heat dissipation capability of the first region with high heat production of the battery cell can be improved, the problem of local overheating of the battery cell is reduced, and the battery cell is ensured to have good working performance.

Description

Technical Field

[0001] The present application relates to battery manufacturing technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] The battery cell is the core component of the battery, directly determining multiple aspects such as performance, capacity, lifespan, and safety. The battery cell can transfer heat to the battery's cold plate through a thermally conductive film layer, dissipating the heat in a timely manner and ensuring optimal battery performance.

[0003] In related art solutions, the thermally conductive film coating the battery cell is typically made of polyethylene terephthalate (PET). During battery charging and discharging, the area near the terminals generates more heat, while the central area generates less. Using related art solutions, the heat cannot be evenly dissipated, potentially causing localized overheating and impacting performance. Utility Model Content

[0004] In order to overcome the above-mentioned defects under the relevant technology, the purpose of this application is to provide a battery cell, a battery and an electrical equipment. This application can improve the heat dissipation capacity of the battery cell near the pole area, thereby reducing the problem of local overheating of the battery cell and ensuring that the battery cell has good working performance.

[0005] In one aspect, the present application provides a battery cell, comprising:

[0006] A cell body, the cell body comprising two end surfaces opposite to each other in a first direction and two first side surfaces opposite to each other in a second direction, each end surface being provided with a pole, at least one first side surface being used for connecting to a cold plate, and each first side surface comprising two first regions in the first direction and a second region located between the two first regions, the two first regions being respectively adjacent to the two end surfaces;

[0007] a first heat-conducting film layer, the first heat-conducting film layer being located on the first region of at least one of the first side surfaces;

[0008] A second heat-conducting film layer is located on a second region of at least one of the first side surfaces, wherein the thermal conductivity of the first heat-conducting film layer is greater than that of the second heat-conducting film layer, and the first direction and the second direction are perpendicular to each other.

[0009] In a possible implementation, the first heat-conducting film layer includes a graphite film layer; and the second heat-conducting film layer includes an ethylene terephthalate film layer.

[0010] In a possible implementation, the graphite film layer includes a stacked polyimide layer, a first adhesive layer, a graphite layer, and a second adhesive layer, wherein the polyimide layer is used to connect the cold plate of the battery, and the second adhesive layer is bonded and fixed to the battery cell body.

[0011] In a possible implementation, the thickness of the graphite layer is 70-80 micrometers; the thickness of the polyimide layer is 18-22 micrometers.

[0012] In one possible implementation, along the first direction, the lengths of the two first regions located on the same first side are equal; the length of the first heat-conducting film layer is 8.2-62.5% of the length of the first side, and the length of the second heat-conducting film layer is 37.5-91.8% of the length of the first side.

[0013] In a possible implementation, the first heat-conducting film layer is provided on both end surfaces, the first heat-conducting film layer on the end surfaces is provided with at least one through hole, and the pole is passed through the through hole.

[0014] In a possible implementation, a ratio of a size of the battery cell body along the first direction to a size of the battery cell body along the second direction is greater than or equal to 5.

[0015] In a possible implementation, the battery cell body further includes two second side surfaces opposite to each other along the third direction, each of the second side surfaces includes two third regions and a fourth region located between the two third regions in the first direction, and the two third regions are respectively close to the two end surfaces;

[0016] The first heat-conducting film layer is located on the third area of at least one of the second side surfaces;

[0017] The second heat-conducting film layer is located on the fourth area of at least one of the second side surfaces;

[0018] The first direction, the second direction and the third direction are perpendicular to each other.

[0019] On the other hand, the present application provides a battery, comprising a shell having a cavity formed therein, a cold plate and at least one battery cell as described above being provided in the cavity, the cold plate being connected to the first and second thermally conductive film layers of the battery cell.

[0020] On the other hand, the present application provides an electrical device, including the battery as described above, or including the battery cell as described above.

[0021] The present application provides a battery cell, a battery and an electrical device, wherein the battery cell includes a battery cell body, a first heat-conducting film layer and a second heat-conducting film layer, the battery cell body includes two end faces opposite to each other along a first direction and two first side faces opposite to each other along a second direction, each end face is provided with a pole, at least one first side face is used to connect to a cold plate, and each first side face includes two first regions and a second region located between the two first regions in the first direction, the two first regions are respectively close to the two end faces; the first heat-conducting film layer is located on the first region of at least one first side face; the second heat-conducting film layer is located on the second region of at least one first side face, wherein the thermal conductivity of the first heat-conducting film layer is greater than the thermal conductivity of the second heat-conducting film layer, and the first direction and the second direction are perpendicular to each other. The present application arranges the first heat-conducting film layer with high thermal conductivity in the first region where the battery cell generates high heat on the first side face and arranges the second heat-conducting film layer in the second region where the battery cell generates low heat, thereby improving the heat dissipation capacity of the first region where the battery cell generates high heat, reducing the problem of local overheating of the battery cell, and ensuring that the battery cell has good working performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A simplified structural diagram of a battery cell provided in one embodiment of the present application;

[0024] Figure 2 A diagram showing the expanded state of the first heat-conducting film layer provided in one embodiment of the present application;

[0025] Figure 3 A simplified structural diagram of a battery cell provided in another embodiment of the present application;

[0026] Figure 4 A diagram showing an expanded state of a first heat-conducting film layer provided in another embodiment of the present application;

[0027] Figure 5 A simplified structural diagram of a battery cell provided in yet another embodiment of the present application;

[0028] Figure 6 A diagram showing the expanded state of the first heat-conducting film layer provided in yet another embodiment of the present application;

[0029] Figure 7 A simplified structural diagram of a battery cell provided in another embodiment of the present application;

[0030] Figure 8A diagram showing the expanded state of the first heat-conducting film layer provided in yet another embodiment of the present application;

[0031] Figure 9 This is a simplified structural diagram of the first heat-conducting film layer provided in one embodiment of the present application.

[0032] Reference numerals:

[0033] 110-end face; 111-pole; 120-first side face;

[0034] 200 - first thermal conductive film layer; 201 - through hole; 210 - polyimide layer; 220 - first adhesive layer; 230 - graphite layer; 240 - second adhesive layer;

[0035] 300- second thermal conductive film layer;

[0036] A1 - first area; A2 - second area; A3 - third area; A4 - fourth area; X - first direction; Y - second direction; Z - third direction. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0038] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0039] As described in the background, when using an ethylene terephthalate film layer to coat battery cells in related art solutions, the heat generated during charging and discharging may not be evenly dissipated from the cells, causing localized overheating and impacting performance. This problem is caused by the low thermal conductivity of the ethylene terephthalate film layer. During charging and discharging, the area of the cell near the terminals generates significant heat, making it difficult to dissipate this heat quickly, resulting in localized overheating.

[0040] In view of this, the embodiments of the present application aim to provide a battery cell, a battery and an electrical device, by setting a first thermally conductive film layer with a high thermal conductivity coefficient in a first area of the battery cell where heat generation is high on the first side, and setting a second thermally conductive film layer in a second area of the battery cell where heat generation is low, thereby improving the heat dissipation capacity of the first area with high heat generation, reducing the problem of local overheating of the battery cell, and ensuring that the battery cell has good working performance.

[0041] The following is a detailed description of the embodiments of the present application in conjunction with the accompanying drawings so that those skilled in the art can understand the contents of the present application in more detail. It should be noted that in the description of this embodiment, the first direction X, the second direction Y, and the third direction Z are three different directions in a three-dimensional space. For example, the first direction X can be the length direction of the battery cell, the second direction Y can be the width direction of the battery cell, and the third direction Z can be the height direction of the battery cell; the first direction X, the second direction Y, and the third direction Z can be perpendicular to each other.

[0042] Please refer to Figure 1 、 Figure 3 、 Figure 5 and Figure 7 , this embodiment provides a battery cell, including:

[0043] The battery cell body is generally in the shape of a rectangular parallelepiped. The battery cell body includes two end faces 110 opposite to each other along the first direction X and two first side faces 120 opposite to each other along the second direction Y. A pole 111 is provided on each end face 110. At least one first side face 120 is used to connect to the cold plate in the battery, thereby transferring the heat of the battery cell to the cold plate to achieve heat exchange and quickly dissipate the heat of the battery cell. Each first side face 120 includes two first areas A1 and a second area A2 located between the two first areas A1 in the first direction X. The two first areas A1 are respectively close to the two end faces 110. For example, the first areas A1 on the two first side faces 120 can correspond one to one, and the second areas A2 can correspond one to one, so as to facilitate the subsequent setting of the thermal conductive film layer.

[0044] The first thermally conductive film layer 200 is located on the first area A1 of at least one first side surface 120. It will be appreciated that the first thermally conductive film layer 200 is located on the first side surface 120 that contacts the cold plate, thereby facilitating rapid transfer of heat generated by the battery cells during operation to the cold plate. When both first side surfaces 120 contact the cold plate, the first thermally conductive film layer 200 can be provided on both first side surfaces 120.

[0045] The second thermally conductive film layer 300 is located on the second area A2 of at least one first side surface 120. It is understood that the second thermally conductive film layer 300 is located on the first side surface 120 that contacts the cold plate, thereby facilitating rapid transfer of heat generated by the battery cells during operation to the cold plate. When both first side surfaces 120 contact the cold plate, the second thermally conductive film layer 300 can be provided on both first side surfaces 120.

[0046] In this embodiment, the thermal conductivity of the first thermally conductive film layer 200 is greater than the thermal conductivity of the second thermally conductive film layer 300, so that the area covered by the first thermally conductive film layer 200 can dissipate heat more quickly, avoiding excessive heat accumulation in the first area A1 during the operation of the battery cell (for example, during charging and discharging), reducing the problem of local overheating of the battery cell, and ensuring that the battery cell has good operating performance.

[0047] As can be seen from the above description, this embodiment provides a first thermally conductive film layer 200 with a high thermal conductivity coefficient in a first region A1 of the first side surface 120 where the battery cell generates high heat, and a second thermally conductive film layer 300 in a second region A2 where the battery cell generates low heat. This improves the heat dissipation capability of the first region A1 where the battery cell generates high heat, reduces the problem of local overheating, and ensures good performance of the battery cell. This embodiment also reduces the manufacturing cost of the battery cell.

[0048] In this embodiment, the first thermally conductive film layer 200 may be, for example, a graphite film layer, and the second thermally conductive film layer 300 may be, for example, an ethylene terephthalate film layer used in related art. Because the thermal conductivity of the graphite film layer is greater than that of the ethylene terephthalate film layer, and the graphite film layer is positioned in the first region A1 of the battery cell, where heat is higher during operation, this embodiment dissipates heat from the first region A1 of the battery cell more quickly than solutions in related art, reducing the risk of localized overheating and ensuring good battery cell performance.

[0049] like Figure 9 As shown, the graphite film layer of this embodiment includes a stacked polyimide layer 210, a first adhesive layer 220, a graphite layer 230, and a second adhesive layer 240. The polyimide layer 210 can be the surface layer, used to connect to the battery's cold plate and provide insulation and thermal conductivity. The second adhesive layer 240 can be the bottom layer, bonded to the battery cell body and providing thermal conductivity between the two. Both the first adhesive layer 220 and the second adhesive layer 240 can be made of thermally conductive adhesive. The graphite layer 230 can be made of either artificial graphite or natural graphite. Artificial graphite can be prepared by carbonizing polyimide at 1300°C, then graphitizing at 2800°C, and then calendering, laminating, and cutting the finished product. Natural graphite can be prepared by acidifying natural graphite flakes to enrich their surface with active groups. The flakes are then washed, dried, and expanded at high temperatures to produce highly expanded vermicular graphite, which is then calendered.

[0050] Furthermore, in this embodiment, the thickness D1 of the graphite layer 230 is 70-80 microns; the thickness D2 of the polyimide layer 210 is 18-22 microns. The specific thicknesses of the graphite layer 230 and the polyimide layer 210 can be selected based on the required thermal conductivity and mechanical properties. Assuming the overall thickness of the graphite film is constant, a greater thickness D1 of the graphite layer 230 results in better thermal conductivity and worse mechanical properties; a greater thickness D2 of the polyimide layer 210 results in worse thermal conductivity and better mechanical properties.

[0051] To simplify the coating of the first thermal conductive film layer 200 , in this embodiment, the lengths of the two first areas A1 on the same first side surface 120 along the first direction X are equal, so that the first thermal conductive film layer 200 material of the same size can be used for coating.

[0052] Optionally, along the first direction X, the length of the first thermally conductive film layer 200 of this embodiment is 8.2-62.5% of the length of the first side surface 120. That is, on the same first side surface 120, the sum of the lengths of the two first thermally conductive film layers 200 is 8.2-62.5% of the length of the first side surface 120. The length of the second thermally conductive film layer 300 is 37.5-91.8% of the length of the first side surface 120. Limiting the lengths of the first and second thermally conductive film layers 200, 300 to within the aforementioned ranges can ensure better heat dissipation uniformity in the battery cell while also ensuring lower manufacturing costs.

[0053] Please continue to refer to Figure 1 、 Figure 3 and Figure 5 In one possible embodiment, both end surfaces 110 of this embodiment are provided with a first thermally conductive film layer 200. The first thermally conductive film layer 200 on the end surface 110 is provided with at least one through-hole 201, through which the pole 111 passes. The through-hole 201 can also be used to provide clearance for structures such as connectors on the end surface 110. The first thermally conductive film layer 200 on the end surface 110 and the first thermally conductive film layer 200 on the adjacent first side surface 120 can be integrally connected (the two can be integrally formed), thereby further improving the heat dissipation capacity of the high-temperature areas of the battery cell, reducing the problem of local overheating of the battery cell, and ensuring good battery cell performance.

[0054] In this embodiment, the ratio of the size of the battery cell body along the first direction X to the size of the battery cell body along the second direction Y is greater than or equal to 5. In other words, the ratio of the length to width of the battery cell is greater than or equal to 5, indicating a battery cell with a large aspect ratio. When the aspect ratio of the battery cell is large, the temperature difference between different areas of the battery cell during operation is large. The solution of this embodiment can better improve the heat dissipation capacity of the high-temperature areas of the battery cell, reduce the problem of local overheating of the battery cell, and ensure the battery cell has good operating performance.

[0055] Please continue to refer to Figure 1 、 Figure 3 、 Figure 5 and Figure 7 The battery cell body of this embodiment further includes two second side surfaces that are opposite each other along the third direction Z (i.e., two side surfaces perpendicular to the paper). Each second side surface includes two third regions A3 and a fourth region A4 located between the two third regions A3 along the first direction X. The two third regions A3 are respectively close to the two end surfaces 110. The first thermally conductive film layer 200 is located on the third region A3 of at least one second side surface; the second thermally conductive film layer 300 is located on the fourth region A4 of at least one second side surface.

[0056] For example, Figure 5 and Figure 7 As shown, along the first direction X, the third area A3 may be equal in length to the first area A1 on the adjacent first side surface 120, and the fourth area A4 may be equal in length to the second area A2 on the adjacent second side surface. Figure 1 and Figure 3 As shown, along the first direction X, the third area A3 may be different in length from the first area A1 on the adjacent first side surface 120, and the fourth area A4 may be different in length from the second area A2 on the adjacent second side surface. The specific sizes of the third area A3 and the fourth area A4 can be set as needed.

[0057] In this embodiment, a first thermally conductive film layer 200 and a second thermally conductive film layer 300 are also provided on the two second side surfaces. Combined with the first thermally conductive film layer 200 and the second thermally conductive film layer 300 on the two first side surfaces 120, the heat generated by the battery cell can be transferred to the cold plate more quickly, thereby improving the heat dissipation efficiency of the battery cell, ensuring the uniformity of heat in various areas of the battery cell, reducing the problem of local overheating of the battery cell, and ensuring that the battery cell has good working performance.

[0058] In this embodiment, the specific coating dimensions of the first heat-conducting film layer 200 and the second heat-conducting film layer 300 on the battery cell can be determined based on actual needs. Several embodiments of different coating solutions are given below.

[0059] Example 1

[0060] like Figure 1 and Figure 2 As shown (where Figure 2 The first thermal conductive film 200 is cut into Figure 2The shape shown makes the width of the first thermally conductive film 200 along the left-right direction as shown in the figure greater than the width of the end face 110 of the battery cell, and a plurality of through holes 201 are processed on the first thermally conductive film 200 so that the poles 111 and connecting pieces on the end face 110 of the battery cell can pass through. Taking one end of the battery cell along the first direction X as an example, when wrapping, the poles 111 and connecting pieces and other structures are first passed through the through holes 201 on the first thermally conductive film 200 so that the end face 110 of the battery cell is covered with the first thermally conductive film 200; since the width of the first thermally conductive film 200 along the left-right direction as shown in the figure is greater than the width of the end face 110 of the battery cell, the excess first thermally conductive film 200 can be bent and wrapped on the two second side faces of the battery cell to cover the third area A3 on the second side face. Then Figure 2 The first thermally conductive film 200 shown is located above and below the through-hole 201 and is wrapped around the two first side surfaces 120 of the battery cell, covering the first area A1 on the first side surface 120. The excess first thermally conductive film 200 is also bent and wrapped around the two second side surfaces of the battery cell. The rest of the battery cell can be covered with the second thermally conductive film 300.

[0061] Example 2

[0062] like Figure 3 and Figure 4 As shown (where Figure 4 The first thermal conductive film 200 is cut into Figure 4 The shape shown in the figure makes the width of the first thermal conductive film 200 along the left-right direction larger than the width of the end face 110 of the battery cell, and multiple through holes 201 are processed on the first thermal conductive film 200 so that the poles 111 and connecting pieces on the end face 110 of the battery cell can pass through. Taking one end of the battery cell along the first direction X as an example, when wrapping, the poles 111 and connecting pieces and other structures are first passed through the through holes 201 on the first thermal conductive film 200 so that the end face 110 of the battery cell is covered with the first thermal conductive film 200. Then Figure 4 The first heat-conducting film 200 shown is located at the left and right sections of the through hole 201 and is respectively wrapped on the two second side surfaces of the battery cell, covering the third area A3 on the second side surface. Figure 4 The first thermally conductive film 200 shown is located above and below the through-hole 201 and is wrapped around the two first side surfaces 120 of the battery cell, covering the first area A1 on the first side surface 120. The excess first thermally conductive film 200 is also bent and wrapped around the two second side surfaces of the battery cell. The rest of the battery cell can be covered with the second thermally conductive film 300.

[0063] Compared with the first embodiment, the present embodiment increases the area of the first heat-conducting film 200 on the second side surface, thereby better dissipating the heat generated in the vicinity of the cell end surface 110 .

[0064] Example 3

[0065] like Figure 5 and Figure 6 As shown (where Figure 6 The first thermal conductive film 200 is cut into Figure 6 The shape shown in FIG2 is a diagram. A plurality of through holes 201 are processed on the raised portion of the upper left corner of the first thermal conductive film 200 so that the pole 111 and the connecting piece on the end face 110 of the battery cell can pass through. Taking one end of the battery cell along the first direction X as an example, when wrapping, the pole 111 and the connecting piece and other structures are first passed through the through holes 201 on the first thermal conductive film 200 so that the end face 110 of the battery cell is covered with the first thermal conductive film 200. Then, Figure 6 The portion to the right of the raised portion of the first heat-conducting film 200 is sequentially wrapped around the first side surface 120 and the second side surface of the battery cell. The remaining portion of the battery cell can be covered with the second heat-conducting film 300.

[0066] Compared with the solutions of the above-mentioned embodiments 1 and 2, in this embodiment, the lengths of the first area A1 on the first side surface 120 and the third area A3 on the second side surface are consistent, and the lengths of the second area A2 and the fourth area A4 are consistent. Therefore, the cutting workload of the first thermal conductive film 200 and the second thermal conductive film 300 can be reduced, thereby improving production efficiency.

[0067] Example 4

[0068] like Figure 7 and Figure 8 As shown (where Figure 8 The first thermal conductive film 200 is cut into Figure 8 The shape shown (for example, a rectangle). Taking one end of the battery cell along the first direction X as an example, when wrapping Figure 8 The first heat-conducting film 200 is sequentially wound around the first side surface 120 and the second side surface of the battery cell. The rest of the battery cell can be covered with the second heat-conducting film 300.

[0069] Compared with the solution of the third embodiment, this embodiment does not cover the end surface 110 of the battery cell, thereby further reducing the workload of cutting the first thermal conductive film 200 and the second thermal conductive film 300 and improving production efficiency.

[0070] This embodiment further provides a battery, including a shell having a cavity formed therein, a cold plate and at least one of the above-mentioned battery cells disposed in the cavity, and the cold plate is connected to the first and second heat-conducting film layers of the battery cell.

[0071] Since the battery of this embodiment adopts the above-mentioned battery cell, the heat dissipation capability of the battery during operation is good, thereby ensuring that the battery has a high operating efficiency.

[0072] This embodiment provides an electrical device, including the above-mentioned battery, or including the above-mentioned battery cell.

[0073] The electrical device may include a battery pack, a vehicle, or an energy storage device. It is understood that, due to the use of the above-mentioned battery, this embodiment can improve the heat dissipation capacity of the electrical device during use, ensuring that the electrical device has good working performance.

[0074] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0075] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0076] It should be noted that in the description of this application, the terms "first" and "second" are used solely to facilitate the description of different components and should not be understood to indicate or imply a sequential relationship, relative importance, or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of such features.

[0077] The various embodiments or implementation methods in this application are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0078] In the description of this application, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: A cell body, the cell body comprising two end surfaces (110) opposite to each other along a first direction and two first side surfaces (120) opposite to each other along a second direction, each end surface (110) being provided with a pole (111), at least one first side surface (120) being used for connecting to a cold plate, and each first side surface (120) comprising two first areas (A1) and a second area (A2) located between the two first areas (A1) in the first direction, the two first areas (A1) being respectively close to the two end surfaces (110); a first heat-conducting film layer (200), the first heat-conducting film layer (200) being located on the first region (A1) of at least one of the first side surfaces (120); A second heat-conducting film layer (300), wherein the second heat-conducting film layer (300) is located on a second area (A2) of at least one of the first side surfaces (120), wherein the thermal conductivity of the first heat-conducting film layer (200) is greater than the thermal conductivity of the second heat-conducting film layer (300), and the first direction and the second direction are perpendicular to each other.

2. The battery cell according to claim 1, characterized in that The first heat-conducting film layer (200) comprises a graphite film layer; and the second heat-conducting film layer (300) comprises an ethylene terephthalate film layer.

3. The battery cell according to claim 2, characterized in that The graphite film layer comprises a stacked polyimide layer (210), a first adhesive layer (220), a graphite layer (230), and a second adhesive layer (240), wherein the polyimide layer (210) is used to connect a cold plate of a battery, and the second adhesive layer (240) is bonded and fixed to the battery cell body.

4. The battery cell according to claim 3, characterized in that The thickness of the graphite layer (230) is 70-80 microns; the thickness of the polyimide layer (210) is 18-22 microns.

5. The battery cell according to claim 1, characterized in that Along the first direction, the lengths of the two first regions (A1) located on the same first side surface (120) are equal; the length of the first heat-conducting film layer (200) is 8.2-62.5% of the length of the first side surface (120), and the length of the second heat-conducting film layer (300) is 37.5-91.8% of the length of the first side surface (120).

6. The battery cell according to claim 1, characterized in that The first heat-conducting film layer (200) is provided on both end surfaces (110), the first heat-conducting film layer (200) located on the end surface (110) is provided with at least one through hole (201), and the pole (111) is passed through the through hole (201).

7. The battery cell according to claim 1, characterized in that A ratio of a size of the battery cell body along the first direction to a size of the battery cell body along the second direction is greater than or equal to 5.

8. The battery cell according to claim 7, characterized in that: The battery cell body further comprises two second side surfaces opposite to each other along a third direction, each of the second side surfaces comprising two third regions (A3) and a fourth region (A4) located between the two third regions (A3) in the first direction, the two third regions (A3) being respectively close to the two end surfaces (110); The first heat-conducting film layer (200) is located on the third area (A3) of at least one of the second side surfaces; The second heat-conducting film layer (300) is located on the fourth area (A4) of at least one of the second side surfaces; The first direction, the second direction and the third direction are perpendicular to each other.

9. A battery, characterized in that: The battery comprises a shell having a cavity formed therein, a cold plate and at least one battery cell according to any one of claims 1 to 8 being arranged in the cavity, and the cold plate being connected to the first thermal conductive film layer and the second thermal conductive film layer of the battery cell.

10. An electrical device, characterized in that: The battery comprises the battery as claimed in claim 9, or the battery cell as claimed in any one of claims 1 to 8.

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