Battery pole piece, battery cell and battery

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pole piece, a battery cell and a battery, the battery pole piece comprises a current collector, a first active material layer and a second active material layer; the first active material layer is arranged on one surface of the current collector, and a plurality of first holes are formed in the first active material layer; the second active material layer is arranged on one surface, deviating from the first active material layer, of the current collector, and a plurality of second holes are formed in the second active material layer; wherein the depth of at least part of the first holes is larger than that of the second holes, and / or the area of at least part of the first holes is larger than that of the second holes.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a battery pole piece, a battery cell and a battery. Background Art

[0002] Electric vehicles are often equipped with battery devices, which are used to provide power to the electric vehicles. The battery device includes multiple batteries, and the battery includes a shell, an electrolyte and a pole piece, and the pole piece and the electrolyte are arranged in the shell. When the battery is working, the pole piece transmits charge through the electrolyte, so the infiltration of the electrolyte into the pole piece is closely related to the energy density and charging speed of the battery. In the related art, the wettability of the electrolyte is poor, which is not conducive to the improvement of the battery energy density and charging speed.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] The purpose of the present disclosure is to provide a battery pole piece, a battery cell and a battery, thereby improving the wettability of the electrolyte to at least a certain extent.

[0005] According to a first aspect of the present disclosure, a battery electrode sheet is provided, the battery electrode sheet comprising:

[0006] current collector;

[0007] A first active material layer, the first active material layer is disposed on one side of the current collector, and the first active material layer is provided with a plurality of first holes;

[0008] a second active material layer, the second active material layer being disposed on a side of the current collector away from the first active material layer, the second active material layer being provided with a plurality of second holes;

[0009] The depth of at least some of the first holes is greater than the depth of the second holes, and / or the area of ​​at least some of the first holes is greater than the area of ​​the second holes.

[0010] According to a second aspect of the present disclosure, a battery cell is provided, the battery cell comprising the above-mentioned battery electrode sheet.

[0011] According to a third aspect of the present disclosure, a battery is provided, comprising the above-mentioned battery cell.

[0012] The battery pole piece provided by the embodiment of the present disclosure includes a current collector, a first active material layer and a second active material layer, the first active material layer and the second active material layer are respectively arranged on the two sides of the current collector, the first active material layer is provided with a plurality of first holes, and the second active material layer is provided with a plurality of second holes. By providing the first holes on the first active material layer and the second holes on the second active material layer, the wetting performance of the electrolyte can be improved, and when making holes on the pole piece, the first holes are first processed on the first active material layer, and then the second holes are processed on the second active material layer. When processing the second holes, the first holes will be backfilled, and the backfilling causes the first holes to become smaller or shallower, thereby affecting the wetting rate of the electrolyte. The present disclosure can solve the problem of the backfilling of the first holes affecting the wetting rate at least to a certain extent by making the depth of at least some of the holes in the plurality of first holes greater than the depth of the second holes, and / or the area of ​​at least some of the holes in the plurality of first holes greater than the area of ​​the second holes, which is beneficial to the improvement of the battery energy density and charging speed.

[0013] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0015] Figure 1 A schematic diagram of a battery pole piece provided for an exemplary embodiment of the present disclosure;

[0016] Figure 2 A schematic diagram of a battery pole piece provided for an exemplary embodiment of the present disclosure;

[0017] Figure 3 A schematic diagram of a battery electrode provided according to an exemplary embodiment of the present disclosure.

[0018] Description of reference numerals:

[0019] 10. Current collector; 101. Central region; 102. Edge region; 20. First active material layer; 21. First hole; 201. First related hole; 30. Second active material layer; 31. Second hole; 301. Second related hole. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0021] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0022] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0023] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to another element (one or more) "upper", "lower", or "inner", "outer", it can not only be directly connected to the other (one or more) elements "upper", "lower", "inner", "outer", but also can be indirectly connected to the other (one or more) elements "upper", "lower", "inner", "outer" through an intermediate element.

[0024] The exemplary embodiment of the present disclosure also provides a battery electrode sheet, such as Figure 1 and Figure 2 As shown, the battery electrode includes: a current collector 10, a first active material layer 20 and a second active material layer 30, the first active material layer 20 is arranged on one side of the current collector 10, and the first active material layer 20 is provided with a plurality of first holes 21; the second active material layer 30 is arranged on the side of the current collector 10 away from the first active material layer 20, and the second active material layer 30 is provided with a plurality of second holes 31; wherein, the depth of at least some of the multiple first holes 21 is greater than the depth of the second holes 31, and / or the area of ​​at least some of the multiple first holes 21 is greater than the area of ​​the second holes 31.

[0025] The battery pole piece provided by the embodiment of the present disclosure includes a current collector 10, a first active material layer 20 and a second active material layer 30, wherein the first active material layer 20 and the second active material layer 30 are respectively arranged on the two sides of the current collector 10, the first active material layer 20 is provided with a plurality of first holes 21, and the second active material layer 30 is provided with a plurality of second holes 31. By providing the first holes 21 on the first active material layer 20 and the second holes 31 on the second active material layer 30, the wetting performance of the electrolyte can be improved, and when making holes on the pole piece, the first holes 21 are first processed on the first active material layer 20, and then the second holes 31 are processed on the second active material layer 30. When processing the second holes 31, the first holes 21 will be backfilled, and the backfilling will cause the first holes 21 to be filled. The hole 21 becomes smaller or shallower, thereby affecting the infiltration rate of the electrolyte. In the embodiment of the present disclosure, during the manufacturing process, the depth of at least some of the multiple first holes 21 is set to be greater than the depth of the second hole 31, and / or the area of ​​at least some of the multiple first holes 21 is set to be greater than the area of ​​the second hole 31, thereby solving the problem of the first holes 21 becoming smaller or shallower due to backfilling during battery electrode manufacturing. In the final product, it is presented that the depth of at least some of the multiple first holes 21 is greater than the depth of the second hole 31, and / or the area of ​​at least some of the multiple first holes 21 is greater than the area of ​​the second hole 31, thereby solving the problem of the infiltration rate affected by the backfilling of the first holes 21 to at least a certain extent, which is beneficial to the improvement of battery energy density and charging speed.

[0026] The following is a detailed description of each part of the battery electrode provided by the embodiment of the present disclosure:

[0027] The battery pole piece includes a current collector 10 and a first active material layer 20 and a second active material layer 30 respectively arranged on both sides of the current collector 10. A plurality of first holes 21 are arranged on the first active material layer 20, and the first holes 21 extend inward from the side of the first active material layer 20 away from the current collector 10 (the first holes 21 have an opening on the side of the first active material layer 20 away from the current collector 10). The plurality of first holes 21 may penetrate the first active material layer 20, or the plurality of first holes 21 may not penetrate the first active material layer 20, or the plurality of first holes 21 partially penetrate the first active material layer 20 and partially do not penetrate the first active material layer 20. A plurality of second holes 31 are arranged on the second active material layer 30, and the second holes 31 extend inward from the side of the second active material layer 30 away from the current collector 10 (the second holes 31 have an opening on the side of the second active material layer 30 away from the current collector 10). The plurality of second pores 31 may penetrate the second active material layer 30 , or may not penetrate the second active material layer 30 , or the plurality of second pores 31 may partially penetrate the second active material layer 30 and partially not penetrate the second active material layer 30 .

[0028] The first active material layer 20 and the second active material layer 30 are respectively coated on the surface of the current collector 10. For example, the electrode powders can be mixed into a coating liquid, the coating liquid is coated on the current collector 10, and then the electrode sheets are formed through processes such as rolling and die cutting.

[0029] The current collector 10 serves as the current output end of the battery cell, and the material is generally copper foil or aluminum foil, or a composite current collector. The battery pole piece can be a positive pole piece or a negative pole piece. The current collector 10 of the positive pole piece is an aluminum current collector, and the positive electrode active material is coated on the surface of the aluminum current collector to form a positive pole piece. The current collector 10 of the negative pole piece is a copper current collector, and the negative electrode active material is coated on the copper current collector to form a negative pole piece. The thickness of the aluminum current collector is greater than the thickness of the copper current collector. Of course, in other embodiments, the current collector 10 can also be made of other materials, and the embodiments of the present disclosure are not limited to this.

[0030] For example, the positive electrode active material of the lithium ion battery can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode active material can be graphite or silicon, etc.

[0031] The first holes 21 in the first active material layer 20 may be round holes, square holes, or long holes, etc., and the second holes 31 in the second active material layer 30 may be round holes, square holes, or long holes, etc. The first active material layer 20 may be provided with multiple rows of first holes 21, and the multiple rows of first holes 21 may be arranged in an aligned manner (matrix distribution), or the multiple rows of first holes 21 may be staggered. The second active material layer 30 may be provided with multiple rows of second holes 31, and the multiple rows of second holes 31 may be arranged in an aligned manner (matrix distribution), or the multiple rows of second holes 31 may be staggered.

[0032] For example, the first hole 21 can be a circular hole, and the second hole 31 is also a circular hole. In the first active material layer 20, the distance between adjacent first holes 21 is 40μm-2000μm, that is, the distance between the centers of the two closest first holes 21 is 40μm-2000μm. For example, the distance between adjacent first holes 21 is 40μm, 50μm, 60μm, 100μm, 200μm, 500μm, 1000μm, 1200μm, 1500μm or 2000μm, etc. In the second active material layer 30, the distance between adjacent second holes 31 is 40μm-2000μm, that is, the distance between the centers of the two closest second holes 31 is 40μm-2000μm. For example, the distance between adjacent second holes 31 is 40 μm, 50 μm, 60 μm, 100 μm, 200 μm, 500 μm, 1000 μm, 1200 μm, 1500 μm or 2000 μm.

[0033] In some feasible embodiments, the depth of the first hole 21 is greater than the depth of the second hole 31. The depth of the first hole 21 is 10 μm-50 μm. For example, the depth of the first hole 21 can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 45 μm or 50 μm, etc. The depth of the first hole 21 refers to the size of the first hole 21 in a direction perpendicular to the current collector 10 when the battery electrode is in a flat state.

[0034] On this basis, the depth of the second hole 31 is 5 μm-40 μm. For example, the depth of the second hole 31 can be 5 μm, 6 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm or 40 μm, etc. The depth of the second hole 31 refers to the size of the second hole 31 in a direction perpendicular to the current collector 10 when the battery electrode is in a flat state.

[0035] The difference between the depth of the first hole 21 and the depth of the second hole 31 is 0.01 μm-10 μm (the difference between the depth of the first hole 21 and the depth of the second hole 31 is greater than 0.01 μm and less than or equal to 10 μm). For example, the difference between the depth of the first hole 21 and the depth of the second hole 31 is 0.1 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 6 μm, 9 μm or 10 μm, etc.

[0036] The depths of the first holes 21 on the first active material layer 20 are the same, and the depths of the second holes 31 on the second active material layer 30 are the same. On this basis, the difference between the depths of the first holes 21 and the second holes 31 is a fixed value, and the fixed value ranges from 0.01 μm to 10 μm.

[0037] It is understandable that the depths of the plurality of first holes 21 on the first active material layer 20 may be different, and / or the depths of the plurality of second holes 31 on the second active material layer 30 may be different. On this basis, the difference between the depth of the first hole 21 and the depth of the second hole 31 is not fixed. At this time, the depth of the first hole 21 being greater than the depth of the second hole 31 can be understood as the depth of the relevant first hole 21 being greater than the depth of the second hole 31.

[0038] For example, there is at least one second related hole 301 among the multiple second holes 31, the depth of the first related hole 201 is greater than the depth of the second related hole 301, the first related hole 201 is any one of the multiple first holes 21, the second related hole 301 is a hole among the multiple second holes 31, and the distance between the second hole 31 and the target area is less than or equal to 50μm (the distance between the second hole 31 and the target area can be the minimum distance between the edge of the target area and the edge of the hole), and the target area is the projection area of ​​the first related hole 201 on the second active material layer 30.

[0039] The distance between the second relevant hole 301 and the target area is less than or equal to 50 μm, which can be understood as the second relevant hole 301 and the target area at least partially overlap, or the second relevant hole 301 and the target area are adjacent. When the first hole 21 and the second hole 31 are aligned, the second relevant hole 301 is the second hole 31 that overlaps with the target area. When the first hole 21 and the second hole 31 are misaligned, the second relevant hole 301 is the second hole 31 that partially overlaps with the target area, or the second relevant hole 301 is the second hole 31 that is closest to the target area.

[0040] Optional, such as Figure 3 As shown, the battery electrode sheet includes an edge area 102 and a central area 101, and the edge area 102 surrounds the central area 101. The minimum distance between the battery electrode sheet and the edge of the battery electrode sheet is within 30 mm, which is the edge area 102. In the central area 101, the maximum difference between the depth of the first hole 21 and the depth of the second hole 31 is 0.01 μm-8 μm, and in the edge area 102, the maximum difference between the depth of the first hole 21 and the depth of the second hole 31 is 1 μm-10 μm. During the manufacturing process of the battery electrode, the first hole 21 is first formed in the first active material layer 20, and then the second hole 31 is formed in the second active material layer 30. During the hole forming process of the second active material layer 30 of the battery electrode, since the force is concentrated in the central area 101 of the electrode, the hole backfill in the central area 101 of the first active material layer 20 is more serious. Therefore, the hole depth difference between the two sides of the central area is smaller than that of the edge area, and there may even be a situation where the hole depth difference between the two sides of the central area is 0. Therefore, the hole depth difference between the two sides of the central area 101 of the electrode is smaller than that of the edge area 102.

[0041] In other feasible embodiments, the area of ​​the first hole 21 is greater than the area of ​​the second hole 31. The area of ​​the first hole 21 refers to the area of ​​the opening of the first hole 21 on the surface of the first active material layer 20 away from the current collector 10, and the area of ​​the second hole 31 refers to the area of ​​the opening of the second hole 31 on the surface of the second active material layer 30 away from the current collector 10.

[0042] The areas of the first holes 21 on the first active material layer 20 may be the same, and the areas of the second holes 31 on the second active material layer 30 may be the same. On this basis, the difference between the areas of the first holes 21 and the second holes 31 is a fixed value.

[0043] It is understandable that the areas of the plurality of first holes 21 on the first active material layer 20 may be different, and / or the areas of the plurality of second holes 31 on the second active material layer 30 may be different. On this basis, the difference between the depth of the first hole 21 and the area of ​​the second hole 31 is not fixed. At this time, the area of ​​the first hole 21 is greater than the area of ​​the second hole 31, which can be understood as the area of ​​the relevant first hole 21 is greater than the area of ​​the second hole 31.

[0044] For example, there is at least one second related hole 301 among the multiple second holes 31, the area of ​​the first related hole 201 is larger than the area of ​​the second related hole 301, the first related hole 201 is any one of the multiple first holes 21, the second related hole 301 is a hole among the multiple second holes 31 whose minimum distance from the target area is less than or equal to 50 μm (the distance between the second hole 31 and the target area is the minimum distance between the hole edge of the second hole 31 and the edge of the target area), and the target area is the projection area of ​​the first related hole 201 on the second active material layer 30.

[0045] The hole whose distance between the second relevant hole 301 and the target area is less than the preset threshold can be understood as the second relevant hole 301 and the target area at least partially overlap, or the second relevant hole 301 and the target area are adjacent. When the first hole 21 and the second hole 31 are aligned, the second relevant hole 301 is the second hole 31 that overlaps with the target area. When the first hole 21 and the second hole 31 are misaligned, the second relevant hole 301 is the second hole 31 that partially overlaps with the target area, or the second relevant hole 301 is the second hole 31 that is closest to the target area.

[0046] It should be noted that in the embodiment of the present disclosure, in the relevant first hole 21 and the second hole 31, the depth of the first hole 21 is greater than the depth of the second hole 31, and the area of ​​the first hole 21 is the same as the area of ​​the second hole 31; or in the relevant first hole 21 and the second hole 31, the depth of the first hole 21 is the same as the depth of the second hole 31, and the area of ​​the first hole 21 is greater than the area of ​​the second hole 31; or in the relevant first hole 21 and the second hole 31, the depth of the first hole 21 is greater than the depth of the second hole 31, and the area of ​​the first hole 21 is greater than the area of ​​the second hole 31.

[0047] In the disclosed embodiment, the battery electrode sheet includes a main body and a tab portion, the tab portion extends from the edge of the main body, and the tab portion is not coated with active material. That is, the first active material layer 20 and the second active material layer 30 are provided on both sides of the main body.

[0048] The battery pole piece provided by the embodiment of the present disclosure includes a current collector 10, a first active material layer 20 and a second active material layer 30, wherein the first active material layer 20 and the second active material layer 30 are respectively arranged on the two sides of the current collector 10, the first active material layer 20 is provided with a plurality of first holes 21, and the second active material layer 30 is provided with a plurality of second holes 31. By providing the first holes 21 on the first active material layer 20 and the second holes 31 on the second active material layer 30, the wetting performance of the electrolyte can be improved, and when making holes on the pole piece, the first holes 21 are first processed on the first active material layer 20, and then the second holes 31 are processed on the second active material layer 30. When processing the second holes 31, the first holes 21 will be backfilled, and the backfilling will cause the first holes 21 to be filled. The hole 21 becomes smaller or shallower, thereby affecting the infiltration rate of the electrolyte. In the embodiment of the present disclosure, during the manufacturing process, the depth of at least some of the multiple first holes 21 is set to be greater than the depth of the second hole 31, and / or the area of ​​at least some of the multiple first holes 21 is set to be greater than the area of ​​the second hole 31, thereby solving the problem of the first holes 21 becoming smaller or shallower due to backfilling during battery electrode manufacturing. In the final product, it is presented that the depth of at least some of the multiple first holes 21 is greater than the depth of the second hole 31, and / or the area of ​​at least some of the multiple first holes 21 is greater than the area of ​​the second hole 31, thereby solving the problem of the infiltration rate affected by the backfilling of the first holes 21 to at least a certain extent, which is beneficial to the improvement of battery energy density and charging speed.

[0049] An exemplary embodiment of the present disclosure further provides a battery cell, which includes the above-mentioned battery electrode sheet.

[0050] Among them, the battery cell can be a wound battery cell or a stacked battery cell. In the wound battery cell, the battery pole sheets and the diaphragm are wound to form the battery cell, and in the stacked battery cell, the battery pole sheets and the diaphragm are folded to form the battery cell.

[0051] The battery cell provided by the embodiment of the present disclosure includes a battery pole piece, in which a first active material layer 20 and a second active material layer 30 are respectively arranged on two sides of a current collector 10, the first active material layer 20 is provided with a plurality of first holes 21, and the second active material layer 30 is provided with a plurality of second holes 31. By providing the first holes 21 on the first active material layer 20 and the second holes 31 on the second active material layer 30, the infiltration performance of the electrolyte can be improved, and when forming holes on the pole piece, the first holes 21 are first processed on the first active material layer 20, and then the first holes 21 are processed on the first active material layer 20. The second holes 31 are then processed on the second active material layer 30. When processing the second holes 31, the first holes 21 will be backfilled. The backfilling causes the first holes 21 to become smaller or shallower, thereby affecting the infiltration rate of the electrolyte. The present disclosure can solve the problem of the backfilling of the first holes 21 affecting the infiltration rate at least to a certain extent by making the depth of at least some of the multiple first holes 21 greater than the depth of the second holes 31, and / or the area of ​​at least some of the multiple first holes 21 greater than the area of ​​the second holes 31, which is beneficial to improving the battery energy density and charging speed.

[0052] An embodiment of the present disclosure also provides a battery, which includes the above-mentioned battery cell.

[0053] The battery may be a prismatic battery, such as a quadrangular battery (square battery) or a hexagonal battery, or a cylindrical battery. In a prismatic battery, the cell may be a wound cell or a laminated cell, and in a cylindrical battery, the cell may be a wound cell.

[0054] Furthermore, the battery provided by the embodiment of the present disclosure may also include a shell, a pole and a current collector, etc. The shell has a receiving cavity, the battery cell is arranged in the receiving cavity of the shell, and an electrolyte is also arranged in the receiving cavity, and the battery cell is at least partially immersed in the electrolyte. The pole is arranged in the shell, and the pole serves as the electrode end of the battery. The current collector is arranged in the receiving cavity, and the current collector connects the battery cell and the pole. The pole piece may also be provided with a pole ear, and the pole ear is connected to the current collector.

[0055] The battery provided by the embodiment of the present disclosure can be applied to electric vehicles. When the battery is used in an electric vehicle, the battery can be integrated into a battery pack, which is installed on the electric vehicle to provide energy to the electric vehicle. In practical applications, the battery pack can be installed on the frame of the electric vehicle. The battery pack can be fixedly connected to the frame. Or the battery pack can be a modular battery pack, which can be detachably connected to the vehicle body for easy replacement.

[0056] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A battery pole piece, characterized in that: The battery pole piece comprises: current collector; A first active material layer, the first active material layer is disposed on one side of the current collector, and the first active material layer is provided with a plurality of first holes; a second active material layer, the second active material layer being disposed on a side of the current collector away from the first active material layer, the second active material layer being provided with a plurality of second holes; The depth of at least some of the first holes is greater than the depth of the second holes, and / or the area of ​​at least some of the first holes is greater than the area of ​​the second holes.

2. The battery pole piece according to claim 1, characterized in that: The depth of the first hole is 10 μm-50 μm.

3. The battery pole piece according to claim 1, characterized in that: The second hole has a depth of 5 μm-40 μm.

4. The battery pole piece according to claim 1, characterized in that: The difference between the depth of the first hole and the depth of the second hole is 0.01 μm-10 μm.

5. The battery pole piece according to claim 1, characterized in that: The distance between adjacent first holes is 40 μm-2000 μm, and the distance between adjacent second holes is 40 μm-2000 μm.

6. The battery pole piece according to claim 1, characterized in that: The battery electrode includes an edge area and a center area, the edge area surrounds the center area, the minimum distance between the battery electrode and the edge of the battery electrode is within 30 mm, the edge area, the maximum difference between the depth of at least one of the first holes and the depth of the second hole in the center area is 0.01μm-8μm, and the maximum difference between the depth of the first hole and the depth of the second hole in the edge area is 1μm-10μm.

7. The battery pole piece according to claim 1, characterized in that: There is at least one second related hole among the multiple second holes, the depth of the first related hole is greater than the depth of the second related hole, and / or the area of ​​the first related hole is greater than the area of ​​the second related hole, the first related hole is any one of the multiple first holes, and the second related hole is a hole among the multiple second holes whose distance from the target area is less than or equal to 50 μm, and the target area is the projection area of ​​the first related hole on the second active material layer.

8. The battery pole piece according to claim 7, characterized in that: The second correlation hole and the target area at least partially overlap, or the second correlation hole and the target area are adjacent.

9. A battery cell, characterized in that: The battery cell comprises the battery pole piece described in any one of claims 1-8.

10. A battery, characterized in that: The battery comprises the battery cell according to claim 9.

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