Battery cell

Abstract

The utility model provides a pole piece, which is used in the technical field of batteries, and particularly relates to a battery cell, which comprises a first pole piece, a second pole piece and a diaphragm, and the first pole piece, the diaphragm and the second pole piece are sequentially stacked and wound into the battery cell; the first surface of the first pole piece comprises a first pasting area and a first empty foil area which are adjacent to each other in a first direction, and the second surface of the first pole piece comprises a second pasting area and a second empty foil area which are adjacent to each other in the first direction; the part, overlapped with the first pasting area in the third direction, of the second empty foil area is a single-sided empty foil area; first ending glue is adhered to the adjoining position of the first pasting area and the first empty foil area, second ending glue is adhered to the adjoining position of the second pasting area and the single-face empty foil area, and third ending glue at least covering a first arc area on the single-face empty foil area is further arranged on the single-face empty foil area. According to the pole piece, the strength of the pole piece on the outer side of the battery cell is protected by arranging the third ending glue in the single-side empty foil area, and abnormal capacity attenuation caused by pole piece breakage due to huge change of the size of the battery cell is prevented.

Description

Technical Field

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

[0002] In the wound lithium-ion battery system, with the increasing demand for higher energy density, the development of thick electrode sheets and silicon negative electrode materials is more urgent. The thick negative electrode material sheets and silicon negative electrode materials are prone to increase in electrode internal stress during the lithiation / delithiation process, resulting in a huge change in volume, which in turn causes the arc area of ​​the outer electrode sheet of the wound battery cell to easily break. The broken electrode sheet cannot continue to exert its capacity, causing a sudden drop in battery capacity and abnormal cycling. Utility Model Content

[0003] In view of this, the present application provides a battery cell, which can protect the strength of the outer electrode sheet of the battery cell and prevent abnormal capacity decay caused by the breakage of the arc area of ​​the outer electrode sheet due to the huge increase in the volume of the battery cell by setting a third finishing glue at the first arc area of ​​the single-sided empty foil area of ​​the first electrode sheet.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A battery cell, comprising a first pole piece, a second pole piece and a diaphragm, wherein the first pole piece, the diaphragm and the second pole piece are stacked and wound in sequence to form the battery cell;

[0006] The first pole piece has a first surface and a second surface which are opposite to each other in the third direction, the first surface includes a first paste coating area and a first empty foil area which are adjacent to each other in the first direction, and the second surface includes a second paste coating area and a second empty foil area which are adjacent to each other in the first direction;

[0007] The portion of the second empty foil area overlapping the first paste application area in the third direction is a single-sided empty foil area;

[0008] A first finishing glue is affixed to the adjacent portion of the first paste-coated area and the first empty foil area, a second finishing glue is affixed to the adjacent portion of the second paste-coated area and the single-sided empty foil area, and a third finishing glue is also provided on the single-sided empty foil area.

[0009] The single-sided empty foil area includes a first arc area, and the third finishing glue at least covers the first arc area.

[0010] Optionally, the single-sided empty foil area includes a connecting area connected to the first arc area and a second arc area connected to the connecting area, the second arc area is closer to the end of the first pole piece in the first direction than the first arc area, and the third finishing glue covers at least the second arc area.

[0011] Optionally, the ratio of the length of the third finishing glue in the first direction to the length of the single-sided empty foil area is 2%-100%.

[0012] Optionally, the third finishing glue and the first finishing glue do not overlap in the third direction of the battery cell.

[0013] Optionally, there are gaps between both ends of the third finishing glue in the first direction of the first pole piece and the second finishing glue and ends of the single-sided empty foil area.

[0014] Optionally, the distance between the third finishing glue and the second finishing glue in the first direction of the first pole piece is L1, the distance between the third finishing glue and the first finishing glue in the first direction of the pole piece is L2, and the ratio of L1 to L2 ranges from 3:2 to 1:1.

[0015] Optionally, one end of the third finishing glue along the direction opposite to the first direction of the first pole piece is adjacent to the second finishing glue, and there is a gap between the other end of the third finishing glue along the first direction of the first pole piece and the end of the single-sided empty foil area.

[0016] Optionally, the third finishing glue is adjacent to the second finishing glue along one end in the opposite direction to the first direction of the first pole piece, and the other end of the third finishing glue along the first direction of the first pole piece is flush with the end of the single-sided empty foil area.

[0017] Optionally, the third finishing glue covers the first circular arc area, the second circular arc area, and a connecting area between the first circular arc area and the second circular arc area.

[0018] Optionally, the third finishing glue at least partially overlaps with the first finishing glue and / or the second finishing glue in the third direction of the battery cell.

[0019] Optionally, two ends of the third finishing glue in the third direction of the battery cell do not exceed two ends of the first finishing glue and / or the second finishing glue.

[0020] Optionally, the first finishing glue does not extend beyond the ends of the second pole piece at two ends of the battery cell in the third direction;

[0021] And / or, the second finishing glue does not extend beyond the two ends of the second pole piece at two ends of the battery cell in the third direction;

[0022] And / or, the third finishing glue does not exceed the two ends of the second pole piece at two ends of the battery cell in the third direction.

[0023] Optionally, a thickness of the third finishing glue is less than or equal to a thickness of the first finishing glue and / or the second finishing glue.

[0024] The pole piece and battery cell provided in the present application can protect the strength of the outer pole piece of the battery cell by setting a third finishing glue at the first arc area of ​​the single-sided empty foil area of ​​the first pole piece, and prevent abnormal capacity decay caused by the breakage of the arc area of ​​the outer pole piece due to the huge increase in the volume of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0026] Figure 1 It is a schematic diagram of a pole piece in the prior art;

[0027] Figure 2 It is a schematic diagram of a battery cell in the prior art;

[0028] Figure 3 A schematic diagram of a pole piece of the present application;

[0029] Figure 4 A schematic diagram of a battery cell of the present application;

[0030] Figure 5 An embodiment of the pole piece of the present application;

[0031] Figure 6 Another embodiment of the pole piece of the present application;

[0032] Figure 7 This is another embodiment of the pole piece of the present application.

[0033] exist Figure 1-Figure 7 middle:

[0034] 1. First pole piece; 11. First surface; 111. First paste coating area; 112. First empty foil area; 12. Second surface; 121. Second paste coating area; 122. Second empty foil area; 1221. Single-sided empty foil area; 2. Second pole piece; 3. Diaphragm; 41. First finishing glue; 42. Second finishing glue; 43. Third finishing glue; 5. Tab glue; 6. Tab protection glue; 71. First arc area; 72. Second arc area. DETAILED DESCRIPTION

[0035] The present application provides a battery cell, which can protect the strength of the outer electrode sheet of the battery cell by setting a third finishing glue at the first arc area of ​​the single-sided empty foil area of ​​the first electrode sheet, and prevent the abnormal capacity attenuation caused by the breakage of the arc area of ​​the outer electrode sheet due to the huge increase in the volume of the battery cell.

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] like Figure 3 As shown, an embodiment of the present application provides a battery cell, comprising a first pole piece 1, a second pole piece 2 and a diaphragm 3, wherein the first pole piece 1, the diaphragm 3 and the second pole piece 2 are stacked and wound in sequence to form a battery cell;

[0038] A first pole piece 1, which is a positive pole piece in this embodiment, has a first direction and a second direction perpendicular to each other, namely, a length direction and a width direction of the first pole piece, namely, an X direction and a Y direction in the figure, and the length of the first pole piece 1 in the first direction is greater than the length in the second direction. The first pole piece also has a third direction, namely, a thickness direction, and the third direction is perpendicular to the first direction and the second direction respectively;

[0039] The first electrode 1 has a first surface 11 and a second surface 12 which are opposite to each other in the third direction. The first surface 11 includes a first paste area 111 and a first empty foil area 112 which are adjacent to each other in the first direction. The adjacent to each other means that the edge of the first paste area 111 is also the edge of the first empty foil area 112, and the active paste on the first paste area is applied to the edge of the first empty foil area 112, the same below; the second surface 12 includes a second paste area 121 and a second empty foil area 122 which are adjacent to each other in the first direction; the first paste area 111 and the second paste area 121 are also provided with a pole ear glue 5 and a pole ear protection glue 6 respectively;

[0040] The portion of the second empty foil area 122 overlapping the first paste coating area 111 in the third direction, i.e., the thickness direction, is a single-sided empty foil area 1221;

[0041] A first finishing glue 41 is attached to the adjacent portion of the first paste coating area 111 and the first empty foil area 112, a second finishing glue 42 is attached to the adjacent portion of the second paste coating area 121 and the single-sided empty foil area 1221, and a third finishing glue 43 is also provided on the single-sided empty foil area 1221;

[0042] like Figure 4 As shown, the battery cell has a first direction D1 and a second direction D2 opposite to each other, D1 is the winding direction of the core, and the battery cell also has a third direction parallel to the second direction of the first electrode sheet 1, that is, the Y direction, and the single-sided empty foil area 1221 forms a first arc area 71 and a second arc area 72 in the first direction and the second direction of the battery cell respectively during winding;

[0043] The third finishing glue 43 at least covers the first arc area 71 .

[0044] The first pole piece 1 provided in the present application is provided with a third finishing glue 43 on the single-sided empty foil area 1221 of the first pole piece 1, and the third finishing glue 43 can at least cover the first arc area 71, so that the first arc area 71 is more tightly bonded to the battery cell, thereby protecting the strength of the outer pole piece of the battery cell formed after winding, and preventing the pole piece from breaking due to the huge increase in the volume of the battery cell, which causes abnormal capacity attenuation.

[0045] In a preferred embodiment, the single-sided empty foil area 1221 includes a connecting area connected to the first arc area 71 and a second arc area 72 connected to the connecting area, the second arc area 72 is closer to the end of the first pole piece in the first direction than the first arc area 71, and the third finishing glue at least covers the second arc area 72.

[0046] Thus, when winding the battery cell, in addition to the first arc region 71 being strengthened and fixed, the second arc region 72 located near the end of the first pole piece in the first direction is also strengthened and fixed, thereby reducing the probability of breakage of the two outermost arc regions of the battery cell.

[0047] In a preferred embodiment, Figure 5-Figure 7 As shown, the length of the third finishing glue 43 in the first direction of the first pole piece accounts for 2%-100% of the length of the single-sided empty foil area 1221. The third finishing glue 43 ensures that at least the first arc area 71 formed when the single-sided empty foil area 1221 is wound into a battery cell is covered, that is, the single-sided empty foil area 1221 covers the middle part of the first direction of the first pole piece. The length of the third finishing glue 43 in the first direction accounts for the length of the single-sided empty foil area 1221. The ratio is set at 2%-100%, which can better protect the strength of the outer pole piece of the wound battery cell. The specific implementation scheme can be selected according to the specific application scenario; preferably, in order to achieve the purpose of increasing the strength of the first pole piece 1 of the outer layer of the battery cell and avoiding the increase of the thickness of the battery cell due to the excessive length of the third finishing glue, the length of the third finishing glue can be set to about 10% of the length of the single-sided empty foil area 1221.

[0048] Figure 5-Figure 7 These three embodiments can all achieve the purpose of reinforcing and fixing the single-sided empty foil area 1221 through the third finishing glue 43, thereby ensuring the strength of the arc area of ​​the outermost first pole piece of the battery cell.

[0049] In a preferred embodiment, the third finishing glue and the first finishing glue do not overlap in the third direction of the battery cell.

[0050] The first finishing glue 41 can fix the first pole piece 1, and if the third finishing glue 43 overlaps with the first finishing glue 41 in the third direction of the battery cell, the overlapping part will waste the strength of protecting the outer pole piece of the battery cell. Therefore, the two are staggered with each other during arrangement, so as to better realize the protection effect and achieve the purpose of strengthening the outer pole piece of the battery cell after winding.

[0051] In a preferred embodiment, Figure 3 , Figure 4 , that is Figure 7 In the illustrated embodiment, the third finishing glue 43 is at one end in the first direction of the first electrode 1, that is, the left end in the figure, and there is a gap between it and the second finishing glue 42, that is, there is a distance between the third finishing glue 43 and the second finishing glue 42; and the other end of the third finishing glue 43 in the first direction, that is, the right end in the figure, has a gap with the right end portion of the single-sided empty foil area, that is, there is a distance between the third finishing glue 43 and the right end portion of the single-sided empty foil area.

[0052] In this way, at least the single-sided empty foil area 1221 between the first finishing glue 41 and the second finishing glue 42 can be strengthened and fixed in the middle of the first direction, while preventing the third finishing glue 43 from being too long to increase the thickness of the battery cell.

[0053] Further, in Figure 7 In the embodiment of the invention, in the first direction of the first pole piece 1, the distance between the third end glue 43 and the second end glue 42 is L1, the distance between the third end glue 43 and the first end glue 41 is L2, and the ratio range of L1 to L2 is 3:2 to 1:1. The purpose of setting such a ratio range is to enable the third end glue 43 to be roughly in the middle of the single-sided empty foil area 1221, so that at least the third end glue 43 can at least cover the first arc area 71 formed when the single-sided empty foil area 1221 is wound into a battery cell, thereby ensuring the strength of the first pole piece 1 of the outer layer of the battery cell.

[0054] In another preferred embodiment, Figure 6 As shown, the third end-end glue 43 is adjacent to the second end-end glue 42 along one end in the opposite direction to the first direction of the first electrode sheet 1, and there is a gap between the other end of the third end-end glue 43 along the first direction of the first sheet 1 and the end of the single-sided empty foil area 1221; Same as the previous embodiment, here, the third end-end glue 43 is adjacent to the second end-end glue 42 along one end in the opposite direction to the first direction of the first electrode sheet 1, which means that the third end-end glue 43 and the second end-end glue 42 can be integrated, or the third end-end glue 43 and the second end-end glue 42 can be separated, and the third end-end glue 43 and the second end-end glue 42 can be aligned at the end of the first direction of the first electrode sheet 1, or overlap together;

[0055] In another preferred embodiment, Figure 5 As shown, the third end-end glue 43 is adjacent to the second end-end glue 42 along one end of the first pole piece 1 in the opposite direction of the first direction, and the other end of the third end-end glue 43 along the first direction of the first pole piece 1 is flush with the end of the single-sided empty foil area 1221; Here, the third end-end glue 43 is adjacent to the second end-end glue 42 at one end of the first pole piece 1 in the opposite direction of the first direction, which means that the third end-end glue 43 and the second end-end glue 42 can be integrated, or the third end-end glue 43 and the second end-end glue 42 are separated, and the third end-end glue 43 and the second end-end glue 42 are just aligned at the end of the first direction of the first pole piece 1, or overlap together; In this embodiment, the thickness range of the third end-end glue 43 is preferably 4-50 μm, and the third end-end glue 43 can cover the active paste by 1-50 mm in the first direction of the first pole piece 1.

[0056] The above two embodiments both increase the sticking area of ​​the third finishing glue, especially Figure 5 The embodiment of the present invention strengthens and fixes the entire single-sided empty foil area, and also fixes the first arc area 71 and the second arc area 72 formed when the single-sided empty foil area 1221 is wound into a battery cell at the same time.

[0057] In a preferred embodiment, the third finishing glue covers the first arc area 71 and the second arc area 72 as well as the connecting area between the first arc area 71 and the second arc area 72 .

[0058] In a preferred embodiment, the third finishing glue can not only cover the first arc area 71 and the second arc area 72 of the single-sided empty foil area, but also cover the section between the first arc area 71 and the second arc area 72. In this way, the third finishing glue 43 can strengthen the strength of the single-sided empty foil area in the first arc area 71 and the second arc area 72 and between the two, further ensure the strength of the first pole piece 1 of the outer layer of the battery cell, and prevent the pole piece from breaking.

[0059] In a preferred embodiment, in the wound battery cell, the third finishing glue 43 at least partially overlaps with the first finishing glue 41 and / or the second finishing glue 42 in the third direction of the battery cell, further enhancing the protection of the outermost arc area of ​​the winding core.

[0060] In a preferred embodiment, the two ends of the third finishing glue 43 in the third direction of the battery cell do not exceed the two ends of the first finishing glue 41 and / or the second finishing glue 42. Since the width of the third finishing glue 43 can ensure the strength of the single-sided empty foil area 1221 at the first arc area 71 and the second arc area 72 on both sides of the battery cell, it does not need to be too wide. This can also optimize the processing process and avoid increasing the processing difficulty.

[0061] Similarly, in a preferred embodiment, the first finishing glue 41 does not exceed the two ends of the second pole piece 2 at both ends of the third direction of the battery cell, and / or the second finishing glue 42 does not exceed the two ends of the second pole piece 2 at both ends of the third direction of the battery cell, and the third finishing glue 43 does not exceed the two ends of the second pole piece 2 at both ends of the third direction of the battery cell. In this way, it is possible to ensure that the strength of the single-sided empty foil area 1221 in the first arc area 71 and the second arc area 72 is strengthened, and its processing process can be optimized to avoid increasing the processing difficulty.

[0062] In a preferred embodiment, the thickness of the third finishing glue is less than or equal to the thickness of the first finishing glue and / or the second finishing glue.

[0063] The thickness of the third finishing glue 43 is not greater than the thickness of the first finishing glue 41 or the second finishing glue 42 , so as to avoid an increase in the thickness of the wound battery cell and reduce the loss of energy density.

[0064] The process of assembling the battery cell: the first pole piece 1, the second pole piece 2 and the separator 3 are wound together to form a wound battery cell, which is packaged with an aluminum-plastic film, injected with electrolyte and then formed by a hot pressing process to obtain a battery cell.

[0065] In order to verify and compare the effects of the embodiments of the present application, the prior art and three embodiments of the present application are compared:

[0066] Prior art embodiment: the single-sided empty foil area of ​​the first pole piece is not covered with the third finishing glue 43, the first pole piece and the second pole piece and the diaphragm are wound together to form a wound battery cell, which is packaged with an aluminum-plastic film, and then injected with an electrolyte and formed by a hot pressing process to obtain a battery cell;

[0067] Embodiment 1 of the present application: The difference from the prior art is that a third finishing glue 43 is provided on the single-sided empty foil area of ​​the first pole piece 1, one end of the third finishing glue 43 in the first direction is adjacent to the second finishing glue 42, and the other end of the third finishing glue 43 is flush with the end of the single-sided empty foil area 1221, that is, the single-sided empty foil area of ​​the first pole piece 1 of the wound battery cell is completely covered by the third finishing glue 43 in the first direction of the first pole piece 1;

[0068] Embodiment 2 of the present application: The difference from Embodiment 1 of the present application is that the third finishing glue 43 is adjacent to the second finishing glue 42 at one end in the first direction, and there is a gap between the other end of the third finishing glue 43 in the first direction and the end of the single-sided empty foil area 1221;

[0069] Example 3 of the present application: The difference from Example 1 of the present application is that there is a gap between the third finishing glue 43 at one end in the first direction, that is, the left end in the figure, and the second finishing glue 42, that is, there is a distance between the third finishing glue 43 and the second finishing glue 42; and there is a gap between the other end of the third finishing glue 43 in the first direction, that is, the right end in the figure, and the right side end portion of the single-sided empty foil area 1221, that is, there is a distance between the third finishing glue 43 and the right side end portion of the single-sided empty foil area 1221.

[0070] The experimental results are as follows:

[0071]

[0072]

[0073] It can be seen that the above three embodiments of the present application can all achieve the effect of improving the strength of the outer pole piece.

[0074] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0075] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0076] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed or recombined, and these decompositions or recombinations should be regarded as equivalent solutions of the present application.

[0077] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0078] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0079] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A battery cell, characterized in that: It comprises a first pole piece, a second pole piece and a diaphragm, wherein the first pole piece, the diaphragm and the second pole piece are stacked and wound in sequence to form the battery core; The first pole piece has a first surface and a second surface which are opposite to each other in the third direction, the first surface includes a first paste coating area and a first empty foil area which are adjacent to each other in the first direction, and the second surface includes a second paste coating area and a second empty foil area which are adjacent to each other in the first direction; The portion of the second empty foil area overlapping the first paste application area in the third direction is a single-sided empty foil area; A first finishing glue is affixed to the adjacent portion of the first paste-coated area and the first empty foil area, a second finishing glue is affixed to the adjacent portion of the second paste-coated area and the single-sided empty foil area, and a third finishing glue is also provided on the single-sided empty foil area; The single-sided empty foil area includes a first arc area, and the third finishing glue at least covers the first arc area.

2. The battery cell according to claim 1, characterized in that: The single-sided empty foil area includes a connecting area connected to the first arc area and a second arc area connected to the connecting area, the second arc area is closer to the end of the first pole piece in the first direction than the first arc area, and the third finishing glue at least covers the second arc area.

3. The battery cell according to claim 1, characterized in that: The ratio of the length of the third finishing glue in the first direction of the first pole piece to the length of the single-sided empty foil area is 2%-100%.

4. The battery cell according to claim 1, characterized in that: The third finishing glue and the first finishing glue and / or the second finishing glue do not overlap in the third direction of the battery cell.

5. The battery cell according to claim 1, characterized in that: There are gaps between both ends of the third finishing glue in the first direction of the first pole piece and the second finishing glue and the end of the single-sided empty foil area.

6. The battery cell according to claim 5, characterized in that: The distance between the third finishing glue and the second finishing glue in the first direction of the first pole piece is L1, the distance between the third finishing glue and the first finishing glue in the first direction of the pole piece is L2, and the ratio of L1 to L2 ranges from 3:2 to 1:

1.

7. The battery cell according to claim 1, characterized in that: One end of the third finishing glue along the direction opposite to the first direction of the first pole piece is adjacent to the second finishing glue, and a gap exists between the other end of the third finishing glue along the first direction of the first pole piece and the end of the single-sided empty foil area.

8. The battery cell according to claim 1, characterized in that: One end of the third finishing glue along the direction opposite to the first direction of the first pole piece is adjacent to the second finishing glue, and the other end of the third finishing glue along the first direction of the first pole piece is flush with the end of the single-sided empty foil area.

9. The battery cell according to claim 2, characterized in that: The third finishing glue covers the first arc area, the second arc area, and the connecting area between the first arc area and the second arc area.

10. The battery cell according to claim 9, characterized in that: The third finishing glue at least partially overlaps with the first finishing glue and / or the second finishing glue in the third direction of the battery cell.

11. The battery cell according to claim 1, characterized in that: Two ends of the third finishing glue in the third direction of the battery cell do not exceed two ends of the first finishing glue and / or the second finishing glue.

12. The battery cell according to claim 1, characterized in that: The first finishing glue does not extend beyond the two ends of the second pole piece at the two ends of the battery cell in the third direction; And / or, the second finishing glue does not extend beyond the two ends of the second pole piece at two ends of the battery cell in the third direction; And / or, the third finishing glue does not exceed the two ends of the second pole piece at two ends of the battery cell in the third direction.

13. The battery cell according to claim 1, characterized in that: The thickness of the third finishing glue is less than or equal to the thickness of the first finishing glue and / or the second finishing glue.

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