Battery cell and battery monomer
By providing an insulating layer in the first compensation area of the separator, the short circuit problem caused by the edge burrs of the battery cell is solved, and the safety and volume energy density of the battery are improved.
Patent Information
- Application Number
- CN202421306326.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-07
AI Technical Summary
In the existing battery cell structure, burrs are prone to occur at the edges of the electrode plate, resulting in short circuit between the positive electrode ear and the negative electrode plate, generating heat and possible thermal runaway.
An insulating layer is provided in the first compensation area of the diaphragm to realize the insulation between the positive electrode ear and the negative electrode sheet, and prevent burrs on the edge of the diaphragm from punctured by the diaphragm.
It effectively avoids the short circuit between the positive electrode ear and the negative electrode sheet, improves the safety of the battery, and the setting of the insulating layer does not occupy the height space of the battery cell, and improves the volume energy density.
Smart Images
Figure CN222673263U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery monomer. Background Art
[0002] In the existing battery cell structure, the negative electrode sheet needs to cover the positive electrode sheet, and the positive electrode tab will pass through the negative electrode active material layer of the negative electrode sheet when it extends from the positive electrode active material layer. When the electrode sheet is die-cut, burrs will appear on the edge of the electrode sheet, and the burrs can easily pierce the diaphragm, causing the positive electrode tab and the negative electrode active material layer of the negative electrode sheet to short-circuit, causing the battery cell to generate a lot of heat and prone to thermal runaway. Therefore, a ceramic insulating layer is usually coated on the edge of the positive electrode sheet (the tab side) to isolate the positive electrode tab from the negative electrode sheet. The insulating ceramic needs to occupy the height space of the battery cell, reducing the volume energy density of the battery cell. Utility Model Content
[0003] The utility model aims to provide a battery cell and a battery monomer to achieve insulation between a positive electrode tab and a negative electrode sheet to prevent a short circuit in the battery cell.
[0004] To achieve this purpose, the technical solution adopted by the utility model is:
[0005] The battery cell of the utility model comprises:
[0006] A positive electrode sheet, the positive electrode sheet comprising a positive electrode active material layer and a positive electrode current collector, the positive electrode active material layer comprising a first edge region and a first main region sequentially connected along a first direction; the thickness of the first main region is greater than the thickness of the first edge region;
[0007] A negative electrode sheet, the negative electrode sheet comprising a negative electrode active material layer and a negative electrode current collector, wherein both ends of the negative electrode active material layer extend beyond the positive electrode active material layer in the first direction;
[0008] A diaphragm, wherein the diaphragm is disposed between the positive electrode sheet and the negative electrode sheet, the diaphragm has a first compensation area, an orthographic projection of the first edge area on a projection plane is located within an orthographic projection of the first compensation area on the projection plane, and the projection plane and a thickness direction of the diaphragm are perpendicular to each other;
[0009] The first compensation area is provided with an insulating layer, and the first direction is the width direction of the diaphragm.
[0010] As an optional solution, the negative electrode active material layer includes a second edge region and a second main region sequentially connected along the first direction, and the thickness of the second main region is greater than the thickness of the second edge region.
[0011] As an optional scheme, the first edge area and the second edge area are located on the same side of the battery cell in the first direction, and in the thickness direction of the diaphragm, the side of the diaphragm close to the first edge area has a first compensation area, or the side of the diaphragm close to the second edge area has a first compensation area, or both sides of the diaphragm have first compensation areas.
[0012] As an optional solution, the first edge region and the second edge region are located on both sides of the battery cell in the first direction; in the thickness direction of the diaphragm, a side of the diaphragm close to the first edge region has a first compensation region;
[0013] Alternatively, the first edge area and the second edge area are located on both sides of the battery cell in the first direction; in the thickness direction of the diaphragm, the diaphragm has the first compensation area on the side close to the first edge area, and the diaphragm has the second compensation area on the side close to the second edge area, and the second compensation area is provided with the insulating layer.
[0014] As an optional solution, in the first direction, the width of the first edge area is d1, 4mm≤d1≤32mm;
[0015] And / or, in the first direction, the first edge region has a first end away from the first main region; in the third direction, a distance from the first end of the first edge region to the diaphragm is h, 0<h≤15 μm.
[0016] As an optional solution, along the direction from the first main region to the first edge region, the insulating layer extends beyond the negative electrode active material layer by a distance d2, 1 mm≤d2≤8 mm.
[0017] As an optional solution, the thickness of the insulating layer gradually decreases along a direction from the first edge region to the first main region.
[0018] As an optional solution, along the direction from the first main region to the first edge region, the insulating layer extends beyond the negative electrode active material layer; along the direction from the first edge region to the first main region, the thickness of the insulating layer gradually decreases.
[0019] As an optional solution, an adhesive layer is provided on a side of the insulating layer away from the first compensation area, and the length direction of the diaphragm is the second direction;
[0020] The adhesive layer and the insulating layer both extend along the second direction; or, the adhesive layer and the insulating layer both are spaced apart from each other along the second direction.
[0021] The battery monomer of the utility model comprises the above-mentioned battery core.
[0022] The beneficial effects of the utility model are:
[0023] The battery cell and battery cell proposed in the utility model realize the insulation setting of the positive electrode tab and the negative electrode sheet by setting an insulating layer in the first compensation area of the diaphragm, so as to avoid the burrs on the edge of the electrode sheet piercing the diaphragm and causing the positive electrode tab and the negative electrode sheet to contact and short-circuit, thereby improving the safety of the battery. Moreover, the insulating layer is set in the first compensation area of the diaphragm, and there is no need to occupy the space of the battery cell along the height direction, thereby improving the volume energy density of the battery. In addition, there is no need to apply an insulating layer on the edge of the positive electrode sheet, which reduces the amount of aluminum foil used and improves the internal space utilization rate of the battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a longitudinal cross-sectional view of the first battery cell provided in the first embodiment of the utility model;
[0025] Figure 2 This is a longitudinal cross-sectional exploded view of the first battery cell provided in the first embodiment of the utility model;
[0026] Figure 3 It is a longitudinal cross-sectional exploded view of the second battery cell provided in the first embodiment of the utility model;
[0027] Figure 4 It is a longitudinal cross-sectional exploded view of the third battery cell provided in the first embodiment of the utility model;
[0028] Figure 5 This is a front view of a diaphragm coated with an insulating layer provided in Embodiment 1 of the present utility model;
[0029] Figure 6 This is a schematic structural diagram of a battery cell with a first positive electrode sheet provided in the first embodiment of the utility model;
[0030] Figure 7 This is a schematic diagram of the structure of a battery cell with a second positive electrode sheet provided in the first embodiment of the present utility model;
[0031] Figure 8 It is a longitudinal cross-sectional exploded view of the second battery cell provided in the second embodiment of the present utility model.
[0032] The names and numbers of the components in the figure are as follows:
[0033] 1. Positive electrode sheet; 11. Positive electrode active material layer; 111. First edge region; 112. First main region; 12. Positive electrode tab; 2. Negative electrode sheet; 21. Negative electrode active material layer; 211. Second edge region; 212. Second main region; 22. Negative electrode tab; 3. Diaphragm; 4. Insulating layer; 41. Liquid leakage port. DETAILED DESCRIPTION
[0034] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.
[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0036] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0037] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.
[0038] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.
[0039] Embodiment 1
[0040] In the existing battery cell structure, burrs will be generated on the edge of the electrode when it is die-cut, and the burrs can easily pierce the diaphragm, causing the positive electrode tab and the negative electrode active material layer of the negative electrode to short-circuit, resulting in a large amount of heat generated in the battery cell, which is prone to thermal runaway. Therefore, a ceramic insulating layer is usually coated on the edge of the positive electrode (the tab side) to isolate the positive electrode tab from the negative electrode. The insulating ceramic needs to occupy the height space of the battery cell, which reduces the volume energy density of the battery cell.
[0041] To solve the above problems, Figure 1 and Figure 2 As shown, this embodiment proposes a battery cell, which includes a positive electrode sheet 1, a negative electrode sheet 2 and a separator 3. The positive electrode sheet 1 includes a positive electrode active material layer 11 and a positive electrode current collector. The positive electrode active material layer 11 includes a first edge area 111 and a first main area 112 connected in sequence along a first direction. The thickness of the first main area 112 is greater than the thickness of the first edge area 111. The negative electrode sheet 2 includes a negative electrode active material layer 21, a negative electrode tab 22 and a negative electrode current collector. The negative electrode active material layer 21 includes a second edge area 211 and a second main area 212 connected in sequence along a first direction. The thickness of the second main area 212 is greater than the thickness of the first edge area 111. In the first direction, both ends of the negative electrode active material layer 21 exceed the positive electrode active material layer 11. The separator 3 is arranged between the positive electrode sheet 1 and the negative electrode sheet 2. The separator 3 has a first compensation area. The orthographic projection of the first edge area 111 on the projection plane is located within the orthographic projection of the first compensation area on the projection plane. The projection plane and the thickness direction of the separator 3 are perpendicular to each other. The first compensation area is provided with an insulating layer 4, and the first direction is the width direction of the diaphragm 3. By providing the insulating layer 4 in the first compensation area of the diaphragm 3, the positive electrode tab 12 and the negative electrode sheet 2 are insulated, so as to avoid the burrs on the edge of the electrode sheet piercing the diaphragm 3 and causing the positive electrode tab 12 to contact and short-circuit with the negative electrode sheet 2, thereby improving the safety of the battery. Moreover, the insulating layer 4 is provided in the first compensation area of the diaphragm 3, and does not need to occupy the space of the battery cell along the height direction (i.e., the first direction), thereby improving the volume energy density of the battery. In addition, since the insulating layer 4 does not need to be coated on the edge of the positive electrode sheet 1, the amount of aluminum foil used is reduced, and the internal space utilization rate of the battery is improved.
[0042] It should be noted that the insulating layer 4 of the present embodiment is a ceramic coating, which has good insulation performance and high bonding strength with the diaphragm 3. In addition, metal compounds or oxide materials with large atomic weights such as calcium phosphate and titanium oxide are added to the ceramic coating, so that they can be detected by X-rays, which plays the role of monitoring the diaphragm 3 covering the pole piece, which is conducive to reducing the width of the diaphragm 3 and increasing the internal space of the battery cell.
[0043] It should also be noted that the orthographic projection of the first edge area 111 on the projection plane is located within the orthographic projection of the first compensation area on the projection plane. This can be understood as: the orthographic projection of the first edge area 111 on the projection plane and the orthographic projection of the first compensation area on the projection plane overlap. It can also be understood as: the orthographic projection of the first edge area 111 on the projection plane is located within the orthographic projection of the first compensation area on the projection plane and do not overlap.
[0044] Specifically, the first edge region 111 and the second edge region 211 of the present embodiment are located on the same side of the battery cell in the first direction. Figure 1 and Figure 2 As shown, in the thickness direction of the diaphragm 3, both sides of the diaphragm 3 have a first compensation area, so that the first edge area 111 and the diaphragm 3 and the second edge area 211 and the diaphragm 3 are filled with an insulating layer 4. The setting of the insulating layer 4 can, on the one hand, improve the insulation performance between the positive electrode tab 12 and the negative electrode sheet 2 to avoid short circuit between the positive electrode tab 12 and the negative electrode sheet 2, and on the other hand, it can supplement the thickness of the edge area of the electrode sheet, increase the pressure between the electrodes during formation and circulation, and improve the electrode edge interface problem.
[0045] In an optional embodiment, if Figure 3 As shown, the first edge region 111 and the second edge region 211 are located on the same side of the battery cell in the first direction. In the thickness direction of the diaphragm 3, the side of the diaphragm 3 close to the first edge region 111 has a first compensation region, and the insulating layer 4 is filled only between the first edge region 111 and the diaphragm 3.
[0046] In another optional embodiment, Figure 4 As shown, the first edge region 111 and the second edge region 211 are located on the same side of the battery cell in the first direction. In the thickness direction of the diaphragm 3, the side of the diaphragm 3 close to the second edge region 211 has a first compensation region, and only the insulating layer 4 is filled between the second edge region 211 and the diaphragm 3.
[0047] like Figure 1As shown, in the first direction, the width of the first edge region 111 is d1, 4mm≤d1≤32mm. The width d1 of the first edge region 111 of this embodiment can be 4mm, 8mm, 12mm, 16mm, 20mm, 24mm, 28mm or 32mm, etc. In the first direction, the first edge region 111 has a first end away from the first main region 112; and / or, in the third direction, the distance from the first end of the first edge region 111 to the diaphragm 3 is h, 0<h≤15μm. The distance from the first end to the diaphragm 3 of this embodiment is h, which can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm or 15μm, etc. By setting the width d1 and the distance h to the above values respectively, the first edge area 111 has an appropriate thinning amount, which can avoid material accumulation at the edge of the electrode during the coating process and the risk of lithium deposition at the edge of the electrode.
[0048] like Figure 1 to Figure 4 As shown, the thickness of the insulating layer 4 gradually decreases along the direction from the first edge region 111 to the first main region 112. Specifically, the gap between the first edge region 111 and the diaphragm 3 and the gap between the second edge region 211 and the diaphragm gradually decrease, so the thickness of the insulating layer 4 is gradually reduced, and the insulating layer 4 only needs to fill the gap between the first edge region 111 and the diaphragm 3 and the gap between the second edge region 211 and the diaphragm, which can save ceramic materials.
[0049] like Figure 1 As shown, along the direction from the first main area 112 to the first edge area 111, the insulating layer 4 extends and exceeds the negative electrode active material layer 21, and the distance of the insulating layer 4 beyond the negative electrode active material layer 21 is d2, 1mm≤d2≤8mm. On the one hand, the insulating layer 4 is designed to extend out of the negative electrode active material layer 21, which facilitates the coating of the insulating layer 4 and reduces the coating accuracy requirements. On the other hand, the insulating layer 4 can also support the tabs to prevent the tabs from collapsing. The distance d2 in this embodiment can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm or 8mm, etc.
[0050] Furthermore, along the direction from the first main area 112 to the first edge area 111, the insulating layer 4 extends and exceeds the negative electrode active material layer 21; along the direction from the first edge area 111 to the first main area 112, the thickness of the insulating layer 4 gradually decreases, which is convenient for coating on the one hand and saves ceramic materials on the other hand.
[0051] In this embodiment, in order to increase the overall viscosity of the battery cell, an adhesive layer is provided on the side of the insulating layer 4 away from the first compensation area, and the length direction of the diaphragm 3 is the second direction. The provision of the adhesive layer can prevent the pole piece from slipping during the preparation of the battery cell, and improve the wrinkling of the pole piece. Among them, the adhesive in the adhesive layer can be one of polyvinylidene fluoride, polyvinyl alcohol, and polyacrylic acid. Of course, the adhesive in the adhesive layer can also be other materials, as long as it has a bonding effect.
[0052] In an optional embodiment, the adhesive layer and the insulating layer 4 both extend along the second direction, that is, the adhesive layer and the insulating layer 4 are coated continuously, and coating is convenient.
[0053] In another optional embodiment, since the bare cells all need to be hot-pressed at high temperature, and the adhesive layer produces adhesion with the corresponding pole piece under high temperature conditions, the pole ear side of the bare cell is too dense to block the flow and infiltration of the electrolyte. Therefore, Figure 5 As shown, the adhesive layer and the insulating layer 4 are both arranged at intervals along the second direction, that is, the adhesive layer and the insulating layer 4 are intermittently coated, so that a leakage port 41 can be formed between two adjacent insulating layers 4 in the length direction of the diaphragm 3, which facilitates the electrolyte to flow through the leakage port 41 and fully infiltrate the inside of the battery cell, thereby improving the electrical performance of the battery cell. Among them, the adhesive layer and the insulating layer 4 can be arranged at equal intervals along the second direction, or they can be arranged at unequal intervals along the second direction.
[0054] In some embodiments, Figure 6 As shown, the positive electrode current collector includes a coating area and a positive electrode tab 12 arranged in sequence along a first direction, the coating area is provided with a positive electrode active material layer 11 on both sides of its thickness direction, and the positive electrode tab 12 has a root arranged close to the coating area, and the root of the positive electrode tab 12 is provided with positive electrode active material on both sides of its thickness direction. The positive electrode active material remaining on the positive electrode tab 12 plays the role of active material during the charge and discharge process of the battery cell, thereby maximizing the space utilization of the battery cell.
[0055] In some embodiments, Figure 7 As shown, the positive electrode current collector includes a coating area, a hollow foil area and a positive electrode ear 12 arranged in sequence along a first direction, and the coating area is provided with a positive electrode active material layer 11 on both sides of the coating area in the thickness direction. The hollow foil area is retained, so that the material of the positive electrode sheet 1 will not be wasted during the preparation of the battery cell, thereby improving the material utilization rate of the positive electrode sheet 1.
[0056] This embodiment also proposes a battery cell, which includes the above-mentioned battery cell. By providing an insulating layer 4 in the first compensation area of the diaphragm 3, the positive electrode tab 12 and the negative electrode sheet 2 are insulated, which prevents the burrs on the edge of the electrode sheet from piercing the diaphragm 3 and causing the positive electrode tab 12 to contact and short-circuit with the negative electrode sheet 2, thereby improving the safety of the battery cell. Moreover, the insulating layer 4 is provided in the first compensation area of the diaphragm 3, and does not need to occupy the space of the battery cell along the height direction, thereby improving the volume energy density of the battery cell. In addition, there is no need to apply the insulating layer 4 on the edge of the positive electrode sheet 1, which reduces the amount of aluminum foil used and improves the internal space utilization of the battery cell.
[0057] Embodiment 2
[0058] like Figure 8 As shown, this embodiment proposes a battery cell, which is basically the same as the battery cell in the first embodiment, and the main difference is that the first edge area 111 and the second edge area 211 are located on both sides of the battery cell in the first direction, and in the thickness direction of the diaphragm 3, the side of the diaphragm 3 close to the first edge area 111 has a first compensation area, and the side of the diaphragm 3 close to the second edge area 211 has a second compensation area, and the second compensation area is provided with an insulating layer 4.
[0059] Specifically, Figure 8 As shown, by providing insulating layers 4 on both sides of the diaphragm 3 along the thickness direction, and the two insulating layers 4 are located on both sides of the diaphragm 3 along the first direction, not only the insulation between the positive electrode tab 12 and the negative electrode sheet 2 is improved, but the insulating layer 4 can also supplement the thickness of the edge area of the electrode sheet.
[0060] In an optional embodiment, the first edge region 111 and the second edge region 211 are located on both sides of the battery cell in the first direction, and in the thickness direction of the diaphragm 3 , a side of the diaphragm 3 close to the first edge region 111 has a first compensation region.
[0061] This embodiment also proposes a battery cell, which includes the above-mentioned battery cell. By providing an insulating layer 4 in the first compensation area of the diaphragm 3, the positive electrode tab 12 and the negative electrode sheet 2 are insulated, which prevents the burrs on the edge of the electrode sheet from piercing the diaphragm 3 and causing the positive electrode tab 12 to contact and short-circuit with the negative electrode sheet 2, thereby improving the safety of the battery cell. Moreover, the insulating layer 4 is provided in the first compensation area of the diaphragm 3, and does not need to occupy the space of the battery cell along the height direction, thereby improving the volume energy density of the battery cell. In addition, there is no need to apply the insulating layer 4 on the edge of the positive electrode sheet 1, which reduces the amount of aluminum foil used and improves the internal space utilization of the battery cell.
[0062] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A battery cell, characterized in that: include: A positive electrode sheet (1), the positive electrode sheet (1) comprising a positive electrode active material layer (11) and a positive electrode current collector, the positive electrode active material layer (11) comprising a first edge region (111) and a first main region (112) sequentially connected along a first direction; the thickness of the first main region (112) is greater than the thickness of the first edge region (111); A negative electrode sheet (2), the negative electrode sheet (2) comprising a negative electrode active material layer (21) and a negative electrode current collector, wherein both ends of the negative electrode active material layer (21) extend beyond the positive electrode active material layer (11) in the first direction; A diaphragm (3), the diaphragm (3) being arranged between the positive electrode sheet (1) and the negative electrode sheet (2), the diaphragm (3) having a first compensation area, the orthographic projection of the first edge area (111) on the projection plane being located within the orthographic projection of the first compensation area on the projection plane, and the projection plane and the thickness direction of the diaphragm (3) being perpendicular to each other; The first compensation area is provided with an insulating layer (4), and the first direction is the width direction of the diaphragm (3).
2. The battery cell according to claim 1, characterized in that: The negative electrode active material layer (21) comprises a second edge region (211) and a second main region (212) which are sequentially connected along a first direction, and the thickness of the second main region (212) is greater than the thickness of the second edge region (211).
3. The battery cell according to claim 2, characterized in that: The first edge region (111) and the second edge region (211) are located on the same side of the battery cell in the first direction; in the thickness direction of the diaphragm (3), the side of the diaphragm (3) close to the first edge region (111) has a first compensation region, or the side of the diaphragm (3) close to the second edge region (211) has a first compensation region, or both sides of the diaphragm (3) have first compensation regions.
4. The battery cell according to claim 2, characterized in that: The first edge region (111) and the second edge region (211) are located on both sides of the battery cell in the first direction; in the thickness direction of the diaphragm (3), a first compensation region is provided on one side of the diaphragm (3) close to the first edge region (111); Alternatively, the first edge region (111) and the second edge region (211) are located on both sides of the battery cell in the first direction; in the thickness direction of the diaphragm (3), the diaphragm (3) has the first compensation region on a side close to the first edge region (111), and the diaphragm (3) has the second compensation region on a side close to the second edge region (211), and the second compensation region is provided with the insulating layer (4).
5. The battery cell according to claim 1, characterized in that: In the first direction, the width of the first edge area (111) is d1, 4mm≤d1≤32mm; And / or, in the first direction, the first edge region (111) has a first end away from the first main region (112); in the third direction, the distance from the first end of the first edge region (111) to the diaphragm (3) is h, 0<h≤15μm.
6. The battery cell according to any one of claims 1 to 5, characterized in that: Along the direction from the first main region (112) to the first edge region (111), the distance that the insulating layer (4) extends beyond the negative electrode active material layer (21) is d2, and 1 mm ≤ d2 ≤ 8 mm.
7. The battery cell according to any one of claims 1 to 5, characterized in that: Along the direction from the first edge region (111) to the first main region (112), the thickness of the insulating layer (4) gradually decreases.
8. The battery cell according to any one of claims 1 to 5, characterized in that: Along the direction from the first main region (112) to the first edge region (111), the insulating layer (4) extends beyond the negative electrode active material layer (21); along the direction from the first edge region (111) to the first main region (112), the thickness of the insulating layer (4) gradually decreases.
9. The battery cell according to any one of claims 1 to 5, characterized in that: A bonding layer is provided on a side of the insulating layer (4) facing away from the first compensation area, and the length direction of the diaphragm (3) is a second direction; The adhesive layer and the insulating layer (4) both extend along the second direction; or, the adhesive layer and the insulating layer (4) are both arranged at intervals along the second direction.
10. A battery cell, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.