Battery cell, battery and power utilization device

Abstract

The utility model relates to the technical field of batteries, and discloses a battery core, a battery and a power utilization device, the battery core comprises an aluminum plastic film, a core body and a protection sheet, the core body is located in the aluminum plastic film, the aluminum plastic film comprises a first shell and a second shell, the first shell and the second shell are connected in a sealed mode, a first concave cavity is formed in the first shell in the direction away from the second shell, and a second concave cavity is formed in the second shell. A protective sheet is arranged at the junction area of the first surface of the core body and the side face of the core body. The junction position of the inner surface, corresponding to the first surface of the core body, of the first concave cavity of the aluminum-plastic film and the inner side face of the first concave cavity is the weak position of the aluminum-plastic film, so that the protective sheet is arranged at the junction area, corresponding to the weak position, of the core body, and the risk that the aluminum-plastic film is extruded by the core body due to expansion can be reduced; therefore, the safety of the battery cell can be improved, and the service life of the battery cell is further ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery cell, a battery and an electrical device using the same. Background Art

[0002] A battery cell is the main component of a battery, which mainly includes a core body and an aluminum-plastic film. The core body is mainly divided into two types: a wound core and a stacked core. The aluminum-plastic film wraps around the outside of the core body to protect the core body.

[0003] For a soft-pack battery cell, during the process of repeated use, the volume of the core body will expand. Especially under the application conditions of high rate and fast charging, in severe cases, the aluminum-plastic film will rupture, and water vapor will enter the inside of the battery cell, resulting in rapid expansion and failure of the core body.

[0004] To solve the above problems and ensure the safety of the core body, a large gap needs to be set between the core body and the aluminum-plastic film to reduce the extrusion of the aluminum-plastic film when the core body expands. However, this solution will result in a loss of the energy density of the battery.

[0005] Therefore, how to improve the safety of the battery cell is a technical problem that those skilled in the art need to solve at present. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a battery cell, a battery and an electrical device using the same, which can effectively improve the safety of the battery cell and thus improve its service life.

[0007] To achieve the above purpose, the utility model provides the following technical solutions:

[0008] A battery cell includes:

[0009] An aluminum-plastic film, which includes a first shell and a second shell. The first shell and the second shell are hermetically connected. A first cavity is arranged in the first shell in a direction away from the second shell;

[0010] A core body, which is arranged inside the aluminum-plastic film. A first surface of the core body faces the first cavity;

[0011] A protection sheet, which is arranged at the intersection area between the first surface and the side surface of the core body.

[0012] In some embodiments, an electrode tab is arranged on one side of the core body. At least partial sections of two side surfaces of the core body adjacent to the surface where the electrode tab is arranged are provided with the protection sheets, and the two protection sheets respectively extend to the first surface.

[0013] In some embodiments, a second concave cavity is provided in the second housing and faces away from the first housing. The first concave cavity and the second concave cavity correspond to each other. The second surface of the core body faces the second concave cavity, and the protective sheet is also provided at at least one side adjacent to the second surface and the edge position adjacent to the second surface.

[0014] In some embodiments, one protective sheet is provided on each side of the core body. The two ends of the two protective sheets extend to the first surface and the second surface respectively, and the second surface is the side of the core body facing the second concave cavity.

[0015] In some embodiments, the core body is a wound core. The circumferential surface of the wound core along the winding direction includes a flat area and an arc area. One end of the protective sheet extends to the area on the flat area close to the arc area, and the other end extends to the area on the arc area close to the flat area.

[0016] In some embodiments, the minimum distance between one side of the section of the protective sheet located in the arc area and the edge of the arc area is between 0 and T / 3, where T is the thickness of the core body in the direction perpendicular to the flat area.

[0017] In some embodiments, the length of the section of the protective sheet located in the flat area in the first direction is not less than 1 mm, and the first direction is the direction from one arc area to the other arc area.

[0018] In some embodiments, the projection of the protective sheet and the tab protection glue of the tab of the core body do not overlap in the second direction, and the second direction is the direction perpendicular to the flat area.

[0019] In some embodiments, a tab is provided on one side of the core body. The length of the protective sheet extending out of the side of the core body where the tab is provided is in the range of 0.2 to D / 2 + 1, including the end point values, and the numerical unit is mm, where D is the depth of the first concave cavity in the direction perpendicular to the first surface.

[0020] In some embodiments, the length of the protective sheet extending out of the side of the core body away from the tab is in the range of 0.2 to D / 2, including the end point values, and the numerical unit is mm.

[0021] In some embodiments, the protective sheet and the end sealing tape of the core body are located on different sides or the same side of the core body.

[0022] In some embodiments, the projection of the protective sheet and the end sealing tape of the core body do not overlap in the second direction, and the second direction is the direction perpendicular to the flat area.

[0023] In some embodiments, two protective sheets are respectively provided on the first side of the side of the core body where the end sealing tape is provided, and two protective sheets are also provided on the second side. The first side and the second side are two sides in the first direction. The distance between the two protective sheets on the same side in the third direction is not less than the length of the end sealing tape in the third direction, and the projections of the two protective sheets and the end sealing tape in the first direction do not overlap. The distance between the two protective sheets on different sides in the first direction is less than the length of the end sealing tape in the first direction. The first direction is the direction from one arc region to the other arc region, and the third direction is the direction from the end of the core body where the tab is provided to the other end of the core body.

[0024] In some embodiments, the protective sheet includes a base material and an adhesive layer. The adhesive layer is provided on one side of the base material, and the adhesive layer is adhered to the outer surface of the core body or the inner surface of the aluminum-plastic film; or adhesive layers are respectively provided on both sides of the base material, and the adhesive layers on both sides of the base material are respectively adhered to the inner surface of the aluminum-plastic film and the outer surface of the core body.

[0025] In some embodiments, the thickness of the protective sheet is between 10 and 40 μm, including the end point values.

[0026] In some embodiments, the protective sheet is a protective adhesive tape.

[0027] A battery includes the battery cell described in any one of the above.

[0028] An electrical device includes the above battery.

[0029] Compared with the prior art, the above technical solution has the following advantages:

[0030] A battery cell, a battery and an electrical device provided by the present utility model include: an aluminum-plastic film, a core body and a protective sheet. The aluminum-plastic film includes a first shell and a second shell. A first cavity is provided in the first shell facing away from the second shell. The core body is disposed in the aluminum-plastic film, and the first surface of the core body faces the first cavity. A protective sheet is provided at the junction area between the first surface of the core body and the side surface of the core body. Since the inner surface of the aluminum-plastic film corresponding to the first surface of the core body in the first cavity and the junction area with the inner side surface of the first cavity are weak positions of the aluminum-plastic film, a protective sheet is provided at the junction area of the core body corresponding to the above weak positions, which can isolate the weak positions of the aluminum-plastic film from the core body to avoid contact between the two, reduce the risk of the aluminum-plastic film being squeezed and broken by the expansion of the core body, so the safety of the battery cell can be improved, and further the service life of the battery cell can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0032] Figure 1 The front view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention;

[0033] Figure 2 The front view structural schematic diagram of a battery cell with two concave cavities provided by a specific embodiment of the present invention;

[0034] Figure 3 The front view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention when a protection sheet is provided on each side of the battery cell;

[0035] Figure 4 The front view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention when the extended position of a protection sheet exceeds the edge of the arc area;

[0036] Figure 5 The front view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention when the protection sheet and the end sealing tape are on the same side;

[0037] Figure 6 The front view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention when the protection sheet and the end sealing tape are on different sides;

[0038] Figure 7 The top view structural schematic diagram of a battery cell provided by a specific embodiment of the present invention;

[0039] Figure 8 The top view structural schematic diagram of the relative position of the protection sheet and the end sealing tape of a battery cell provided by a specific embodiment of the present invention;

[0040] Figure 9 The cross-sectional view structural schematic diagram of a protection sheet of a battery cell provided by a specific embodiment of the present invention;

[0041] Figure 10 The cross-sectional view structural schematic diagram of another protection sheet of a battery cell provided by a specific embodiment of the present invention.

[0042] The reference signs are as follows:

[0043] 10 - Aluminum-plastic film, 11 - First housing, 111 - First cavity, 12 - Second housing, 121 - Second cavity;

[0044] 20 - Core body, 201 - Straight area, 202 - Arc area, 21 - First surface, 22 - Second surface, 23 - Tab, 231 - Tab protective glue, 24 - Ending adhesive tape;

[0045] 30 - Protective sheet, 31 - Substrate, 32 - Adhesive layer. Detailed implementation mode

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0047] Please refer to Figure 1 , a battery cell provided by an embodiment of the present invention includes: an aluminum-plastic film 10, a core body 20, and a protective sheet 30. The aluminum-plastic film 10 includes a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are hermetically connected to prevent moisture from entering the interior of the aluminum-plastic film 10. A first cavity 111 is provided in the first housing 11 in a direction away from the second housing 12. The core body 20 is disposed inside the aluminum-plastic film 10, and the aluminum-plastic film 10 can protect the core body 20. The first surface 21 of the core body 20 faces the first cavity 111, and a protective sheet 30 is provided at the junction area between the first surface 21 of the core body 20 and the side surface of the core body 20. Since the inner surface of the first cavity 111 of the aluminum-plastic film 10 corresponding to the first surface 21 of the core body 20 and the junction position with the inner side surface of the first cavity 111 is a weak position of the aluminum-plastic film 10, a protective sheet 30 is provided at the junction area of the core body 20 corresponding to the above weak position, which can reduce the risk of the aluminum-plastic film 10 being squeezed and broken by the expansion of the core body 20. Therefore, the safety of the battery cell can be improved, and further the service life of the battery cell can be ensured. The protective sheet 30 can be selected as adhesive tape. The thickness of the protective sheet 30 is between 10 and 40 μm, including the end point values. If the thickness of the protective sheet 30 is too thin, the protection effect will be affected and the process control is difficult. If it is too thick, it may cause the thickness of the core body 20 to exceed the standard and result in a loss of ED (English name: Energy Density, Chinese name: Energy Density, abbreviated as ED).

[0048] In some embodiments, a tab 23 is provided on one side of the core 20, and protective sheets 30 are provided on at least partial sections of two side surfaces of the core 20. These two side surfaces are adjacent to the side of the core 20 where the tab 23 is provided, and the two protective sheets 30 extend to the first surface 21 of the core 20. For example Figure 1 As shown, a protective sheet 30 can be provided on each side of the core 20 near the first surface 21, and the two protective sheets 30 extend to the first surface 21 respectively. Since the edge positions on both sides of the first cavity 111 are deformed greatly during molding, they are the weak positions of the first housing 11. The edge positions on both sides of the first cavity 111 correspond to the two sides of the surface of the core 20 facing the first cavity 111. Therefore, by providing the protective sheets 30 at the edge positions of the core 20 and the first cavity 111, the strength here can be effectively enhanced, and the edge positions of the first housing 11 can be prevented from being damaged due to the expansion of the core 20. Therefore, it is necessary to first ensure that the edge positions of the first cavity 111 are not easily broken. Further, protective sheets 30 can also be provided at other edge positions of the core 20 corresponding to the aluminum-plastic film 10.

[0049] In some embodiments, such as Figure 2 As shown, a second cavity 121 is provided in the second housing 12 facing away from the first housing 11. The first cavity 111 and the second cavity 121 correspond to each other. At this time, the aluminum-plastic film 10 has a double-sided dimpled structure. The second surface 22 of the core 20 faces the second cavity 121, and protective sheets 30 are also provided at at least one side surface adjacent to the second surface 22 and the edge positions adjacent to the second surface 22. The protective sheet 30 can also be only located in the deeper one of the first cavity 111 and the second cavity 121. For example, when the depth of the first cavity 111 is deeper, the protective sheet 30 is located between the core 20 and the first cavity 111. When the depth of the second cavity 121 is deeper, the protective sheet 30 is located between the core 20 and the second cavity 121. When the depth difference between the first cavity 111 and the second cavity 121 is not large, protective sheets 30 can be provided in at least one of the cavities. For example, when the depth ratio T1:T2 of the first cavity 111 and the second cavity 121 is in the range of 1.1:1 to 1 to 1.1, protective sheets 30 are respectively provided between the core 20 and the first cavity 111 and the second cavity 121, or a protective sheet 30 is only provided between the first cavity 111 and the core 20, or a protective sheet 30 is only provided between the second cavity 121 and the core 20.

[0050] In some embodiments, such as Figure 3As shown, a protective sheet 30 is provided on each side of the core body 20. The two ends of the two protective sheets 30 extend to the first surface 21 and the second surface 22 respectively. By providing a protective sheet 30 on each side of the core body 20, compared with providing a protective sheet 30 on each side of the upper part and each side of the lower part of the core body 20, the number of protective sheets 30 can be reduced, and it is convenient for mounting the protective sheets 30.

[0051] In some embodiments, referring again to Figure 1 , the core body 20 is a wound core, that is, the core body 20 is formed by winding. The circumferential surface of the wound core along the winding direction includes a flat area 201 and an arc area 202. Correspondingly, the weak position of the first concave cavity 111 of the aluminum-plastic film 10 corresponds to the junction position of the flat area 201 and the arc area 202 of the core body 20. For such a wound core structure, one end of the protective sheet 30 can extend to the area on the flat area 201 close to the arc area 202, and the other end can extend to the area on the arc area 202 close to the flat area 201. The position where the protective sheet 30 extends to the arc area 202 can exceed the edge position of the arc area 202 in the top view projection, as specifically shown in Figure 4 . The extending lengths of the two ends of the protective sheet 30 can be determined according to the actual situation, and this embodiment does not make specific limitations thereon, as long as it is not solely located in the flat area 201 or the arc area 202.

[0052] It should be noted that the above embodiments are only described by taking the wound core as an example. In addition to the wound core, a stacked core can also be selected as the core body 20 structure of the battery cell. For example, the stacked core can be formed by stacking rectangular battery sheets. For example, at least one protective sheet 30 can be provided on the first surface 21 of the stacked core and on each side adjacent to the first surface 21, where the first surface 21 is the surface of the stacked core facing the first concave cavity 111.

[0053] In some embodiments, as shown in Figure 5 , the minimum distance L1 between one side of the section of the protective sheet 30 located in the arc area 202 and the edge of the arc area 202 is between 0 and T / 3, where T is the thickness of the core body 20 in the direction from the first housing 11 to the second housing 12. The length L2 of the section of the protective sheet 30 located in the flat area 201 in the first direction is not less than 1 mm, and the first direction is the direction from one arc area 202 to the other arc area 202, such as the X direction shown in Figure 5 . The projection of the protective sheet 30 and the tab protection glue 231 of the tab 23 of the core body 20 in the second direction does not overlap, that is, the distance L3 between one side of the protective sheet 30 located on the flat area 201 and one side of the tab protection glue 231 is greater than or equal to zero, and the second direction is the direction perpendicular to the flat area 201, such as the Z direction shown in Figure 5 .

[0054] In some embodiments, as shown inFigure 7 As shown, a tab 23 is provided on one side of the core 20. The length d1 of the protective sheet 30 extending from the side of the core 20 where the tab 23 is provided is in the range of 0.2 to D / 2 + 1, including the end values, and the numerical unit is mm, where D is the depth of the first cavity 111 in the direction perpendicular to the first surface 21. The length d2 of the protective sheet 30 extending from the side of the core 20 away from the tab 23 is in the range of 0.2 to D / 2, including the end values, and the numerical unit is mm.

[0055] In some embodiments, for the structure where the core 20 is provided with a finishing adhesive tape 24, the protective sheet 30 and the finishing adhesive tape 24 of the core 20 are located on different sides or the same side of the core 20, such as Figure 5 As shown, both the finishing adhesive tape 24 and the protective sheet 30 are located on the upper side of the core 20, as Figure 6 As shown, the finishing adhesive tape 24 is located on the lower side of the core 20, and the protective sheet 30 is located on the upper side of the core 20.

[0056] In some embodiments, such as Figure 8 As shown, the projections of the protective sheet 30 and the finishing adhesive tape 24 of the core 20 in the second direction do not overlap, so as to avoid causing ED loss of the core 20, where the second direction is the direction perpendicular to the flat area 201, such as Figure 5 or Figure 6 the Z direction described in

[0057] In some embodiments, when there is no overlap between the finishing adhesive tape 24 and the protective sheet 30 in the third direction, the protective sheets 30 on both sides of the core 20 can be designed as a whole structure, that is, both protective sheets 30 extend from one end of the core 20 where the tab 23 is provided to the end of the core 20 away from the tab 23; in the case of overlap in the third direction, the protective sheets 30 on both sides of the core 20 can be separately arranged to avoid the finishing adhesive tape 24 when applied to the core 20 with a narrow width. Specifically, as Figure 8 As shown, two protective sheets 30 are respectively provided on the first side of the surface of the core 20 where the finishing adhesive tape 24 is provided, and two protective sheets 30 are also provided on the second side. The first side and the second side are the two sides of the core 20 in the first direction. The distance between the two protective sheets 30 on the same side in the third direction is not less than the length of the finishing adhesive tape 24 in the third direction, and the projections of the two protective sheets 30 and the finishing adhesive tape 24 in the first direction do not overlap, that is, the dimension d4 is greater than or equal to zero. The distance between the two protective sheets 30 on different sides in the first direction is less than the length of the finishing adhesive tape 24 in the first direction, that is, the dimension L4 is greater than or equal to zero. The first direction is the direction from one arc area 202 to the other arc area 202, such as Figure 7 the X direction shown in Figure 7The Y direction shown.

[0058] In some embodiments, the protective sheet 30 includes a base material 31 and an adhesive layer 32. An adhesive layer 32 is provided on one side of the base material 31. The adhesive layer 32 is adhered to the outer surface of the core 20 or the inner surface of the aluminum-plastic film 10. This double-layer structure of the protective sheet 30 has better manufacturability and lower cost. Or adhesive layers 32 are respectively provided on both sides of the base material 31, and the adhesive layers 32 on both sides of the base material 31 are respectively adhered to the inner surface of the aluminum-plastic film 10 and the outer surface of the core 20 to improve the connection stability of the protective sheet 30 relative to the aluminum-plastic film 10 and the core 20.

[0059] The embodiment of the present utility model also provides a battery, including the battery cell provided in any one of the above embodiments. The beneficial effects of the battery can refer to the above battery cell and will not be elaborated here.

[0060] The embodiment of the present utility model also provides an electrical device, including the battery provided in the above embodiment. Regarding the beneficial effects of the electrical device, reference can be made to the above battery cell and will not be elaborated here.

[0061] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0062] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0063] The above has introduced in detail a battery cell, a battery and an electrical device provided by the present utility model. Specific examples are used herein to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the core idea of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. A battery cell, characterized in that: include: An aluminum-plastic film (10), the aluminum-plastic film (10) comprising a first shell (11) and a second shell (12), the first shell (11) and the second shell (12) being sealed and connected, and a first concave cavity (111) being provided in the first shell (11) in a direction away from the second shell (12); A core body (20), the core body (20) being arranged in the aluminum-plastic film (10), and the first surface (21) of the core body (20) facing the first concave cavity (111); A protective sheet (30) is provided at a junction area between the first surface (21) and a side surface of the core (20).

2. The battery cell according to claim 1, characterized in that: A pole ear (23) is provided on one side of the core (20), and at least partial sections of two side surfaces of the core (20) adjacent to the side provided with the pole ear (23) are respectively provided with the protection sheets (30), and the two protection sheets (30) respectively extend to the first surface (21).

3. The battery cell according to claim 1, characterized in that: A second cavity (121) is provided in the second shell (12) in a direction away from the first shell (11); the first cavity (111) and the second cavity (121) correspond to each other; the second surface (22) of the core (20) faces the second cavity (121); and the protective sheet (30) is also provided on at least one side surface adjacent to the second surface (22) and at an edge position adjacent to the second surface (22).

4. The battery cell according to claim 3, characterized in that: A protective sheet (30) is provided on each side of the core (20), and two ends of the two protective sheets (30) extend to the first surface (21) and the second surface (22) respectively, and the second surface (22) is a side of the core (20) facing the second cavity (121).

5. The battery cell according to any one of claims 1 to 4, characterized in that: The core body (20) is a winding core, the circumferential surface of the winding core along the winding direction comprises a straight area (201) and an arc area (202), one end of the protection sheet (30) extends to an area on the straight area (201) close to the arc area (202), and the other end extends to an area on the arc area (202) close to the straight area (201).

6. The battery cell according to claim 5, characterized in that: The minimum spacing between one side of the section of the protection sheet (30) located in the arc region (202) and the edge of the arc region (202) is between 0 and T / 3, wherein T is the thickness of the core (20) in a direction perpendicular to the straight region (201).

7. The battery cell according to claim 5, characterized in that: The length of the section of the protection sheet (30) located in the straight area (201) in the first direction is not less than 1 mm, and the first direction is the direction from one of the circular arc areas (202) to another of the circular arc areas (202).

8. The battery cell according to claim 5, characterized in that: The protection sheet (30) and the tab protection glue (231) of the tab (23) of the core (20) do not overlap in projection in a second direction, and the second direction is a direction perpendicular to the straight area (201).

9. The battery cell according to claim 1, characterized in that: A pole ear (23) is provided on one side of the core body (20), and a length of the protective sheet (30) extending from the side of the core body (20) provided with the pole ear (23) is in the range of 0.2 to D / 2+1, including the endpoint value, and the numerical unit is mm, wherein D is the depth of the first cavity (111) in a direction perpendicular to the first surface (21).

10. The battery cell according to claim 9, characterized in that: The length of the protective sheet (30) extending from the side of the core (20) away from the pole ear (23) is in the range of 0.2 to D / 2, including the endpoint value, and the numerical unit is mm.

11. The battery cell according to claim 5, characterized in that: The protective sheet (30) and the finishing tape (24) of the core (20) are located on different sides or the same side of the core (20).

12. The battery cell according to claim 5, characterized in that: The protection sheet (30) and the finishing tape (24) of the core (20) do not overlap in projection in the second direction, and the second direction is a direction perpendicular to the straight area (201).

13. The battery cell according to claim 5, characterized in that: Two protective sheets (30) are respectively provided on the first side of a surface of the core (20) on which the closing tape (24) is provided, and two protective sheets (30) are also provided on the second side. The first side and the second side are two sides in a first direction. The spacing between the two protective sheets (30) located on the same side in a third direction is not less than the length of the closing tape (24) in the third direction. The projections of the two protective sheets (30) and the closing tape (24) in the first direction do not overlap. The spacing between the two protective sheets (30) located on different sides in the first direction is less than the length of the closing tape (24) in the first direction. The first direction is the direction from one of the circular arc areas (202) to the other circular arc area (202). The third direction is the direction from one end of the core (20) on which the pole ear (23) is provided to the other end of the core (20).

14. The battery cell according to claim 1, characterized in that: The protective sheet (30) comprises a substrate (31) and an adhesive layer (32); the adhesive layer (32) is provided on one side of the substrate (31), and the adhesive layer (32) is adhered to the outer surface of the core (20) or to the inner surface of the aluminum-plastic film (10); or the substrate (31) has one layer of adhesive layer (32) on both sides, and the adhesive layers (32) on both sides of the substrate (31) are adhered to the inner surface of the aluminum-plastic film (10) and the outer surface of the core (20), respectively.

15. The battery cell according to claim 1, characterized in that: The thickness of the protective sheet (30) is between 10 and 40 μm, including the end values.

16. The battery cell according to claim 1, characterized in that: The protective sheet (30) is adhesive tape.

17. A battery, characterized in that: A battery cell comprising any one of claims 1 to 16.

18. An electrical device, characterized in that: Comprising the battery of claim 17.

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