Cell and battery

Abstract

Provided in the present application are a cell and a battery. The cell comprises a first stacked core and a second stacked core which are arranged in a stacked manner; and in a first direction of the cell, an end of the second stacked core exceeds an end of the first stacked core, and the first stacked core and the second stacked core are connected by means of an adhesive layer, wherein in the first direction of the cell, the adhesive layer exceeds the end of the first stacked core. By means of such arrangement, the adhesive layer exceeds the end of the first stacked core, which has a relatively small size, in the first direction, i.e., the length and width direction of the cell, and the whole bottom of the first stacked core can be firmly adhered to the second stacked core by means of the adhesive layer, so that the risks of shifting and slipping are reduced and avoided, thereby further improving the safety and reliability of batteries.

Description

Cells and batteries Technical Field

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

[0002] In related technologies, stepped laminated batteries composed of laminated cores of various sizes have been gradually applied to various products to adapt to the battery slot structure of terminal products.

[0003] However, in this type of battery, there is a risk of displacement and falling off due to poor bonding between stacked cores of different sizes, affecting the safety and reliability of the battery. Summary of the Invention

[0004] In view of this, the present application provides a battery cell and a battery to solve the problem in the prior art that the junction of the stacked core combination of batteries is not firmly bonded, resulting in the risk of displacement and falling off.

[0005] In order to achieve the above objectives, this application provides the following technical solutions.

[0006] In a first aspect, the present application provides a battery core comprising a first core stack and a second core stack arranged in a stacked manner, wherein in a first direction of the battery core, an end portion of the second core stack exceeds an end portion of the first core stack, and the first core stack and the second core stack are connected by an adhesive layer; wherein,

[0007] In a first direction of the battery cell, the adhesive layer extends beyond an end portion of the first core stack.

[0008] Optionally, in a first direction of the battery core, the adhesive layer covers a blank area on the surface of the second core stack, where the first direction is a length direction or a width direction of the battery core.

[0009] Optionally, in the second direction of the battery core, the orthographic projection area of ​​the adhesive layer is 20%-100% of the orthographic projection area of ​​the second core stack.

[0010] Optionally, in the second direction of the battery cell, the thickness of the adhesive layer is h, the thickness of the paste layer of the first stacked core and the second stacked core is H, and h≤H.

[0011] Optionally, in the width direction of the battery cell, the width of the first core stack is 5%-95% of the width of the second core stack.

[0012] Optionally, in the length direction of the battery core, the length of the first core stack is 5%-95% of the length of the second core stack.

[0013] Optionally, an additional layer is provided on at least one side of the adhesive layer, and in a second direction of the battery core, the orthographic projection of the end of the first core stack on the additional layer does not exceed the additional layer, and the second direction is the height direction of the battery core.

[0014] Optionally, in the first direction of the battery core, the adhesive layer extends beyond the additional layer or the adhesive layer is flush with an edge of the additional layer.

[0015] Optionally, the additional layer is a local structure of the covering body, and the covering body covers the end portion of the first stacked core.

[0016] Optionally, the additional layer is an independent structure disposed on the adhesive layer.

[0017] Optionally, the additional layer is an independent structure bonded to the adhesive layer.

[0018] Optionally, the additional layer and the adhesive layer are an integral structure, and the additional layer has a sticky surface.

[0019] Optionally, the additional layer includes at least one of a diaphragm cut body and a ceramic sprayed body.

[0020] Optionally, the additional layer includes a paste thickening layer formed on the paste layer of the second core stack.

[0021] Optionally, the additional layer includes adhesive tape bonded to the adhesive layer.

[0022] Optionally, the bonding layer includes a base layer and a glue layer composited on both side surfaces of the base layer, and the additional layer is a local protrusion integrated with the glue layer.

[0023] Optionally, in the first direction of the battery cell, the distance between the inner edge of the sheath and the edge of the first pole piece of the first stacked core is X1, the second pole piece of the first stacked core has opposite polarity to the first pole piece, and the second pole piece extends beyond the first pole piece, and X1 ≥ 1 mm.

[0024] Optionally, in the first direction of the battery cell, a distance between an inner edge of the additional layer and an edge of a first pole piece of the first stacked core is X1, a distance between an outer edge of the additional layer and an edge of a second pole piece of the first stacked core is X2, the polarities of the first pole piece and the second pole piece are opposite, and the second pole piece extends beyond the first pole piece;

[0025] The additional layer is an independent structure laid or bonded on the adhesive layer, 0.2mm≤X1≤5mm, and / or, X2≥0.2mm.

[0026] Optionally, in the first direction of the battery cell, the distance between the inner edge of the additional layer and the edge of the first electrode piece of the first stacked core is X1, the distance between the outer edge of the additional layer and the edge of the second electrode piece of the first stacked core is X2, the polarity of the first electrode piece is opposite to that of the second electrode piece, and the second electrode piece extends beyond the first electrode piece; wherein,

[0027] The additional layer and the adhesive layer are an integral structure, X1 ≥ 1 mm, and / or X2 ≥ 1 mm.

[0028] In a second aspect, the present application provides a battery comprising the battery cell described in any one of the above items.

[0029] The battery cell provided in the present application includes a first core stack and a second core stack arranged in a stacked manner. In the first direction of the battery cell, the end of the second core stack extends beyond the end of the first core stack, and the first core stack and the second core stack are connected by an adhesive layer. Specifically, in the first direction of the battery cell, the adhesive layer extends beyond the end of the first core stack. In this manner, the adhesive layer extends beyond the end of the smaller first core stack in the first direction, that is, in the length and width directions of the battery cell. The entire bottom of the first core stack can be more firmly bonded to the second core stack through the adhesive layer, thereby reducing and avoiding the risk of displacement and slippage, thereby improving the safety and reliability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0031] FIG1 is a schematic cross-sectional view of a stepped laminated battery in the related art;

[0032] FIG2 is a cross-sectional schematic diagram of a battery cell provided by an embodiment of the present application in which the additional layer is an independent structure;

[0033] FIG3 is a cross-sectional schematic diagram of a battery cell provided by an embodiment of the present application in which the adhesive layer and the additional layer are integrated into a structure;

[0034] FIG4 is a cross-sectional schematic diagram of a battery cell provided by an embodiment of the present application, in which the adhesive layer extends to a blank area;

[0035] FIG5 is a cross-sectional schematic diagram of a covering body provided at the end of a first stack of battery cells provided in an embodiment of the present application.

[0036] Reference numerals: 1. first core stack; 2. second core stack; 3. adhesive layer; 4. additional layer; 5. covering body. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] As shown in Figure 1, in related art, to adapt to the battery slot structure of the end product, multiple stacked cores of different sizes are combined to form a stepped laminated battery. In this type of battery, there is a risk of poor bonding between stacked cores of different sizes, leading to displacement and detachment, affecting the safety and reliability of the battery.

[0039] To address the above-mentioned issues, as shown in Figures 2 to 5, embodiments of the present application provide a battery cell comprising a stacked first core 1 and a second core 2. Each of the first and second cores 1 and 2 includes a multi-layer stack of positive electrode sheets, a separator, and negative electrode sheets. In a first direction of the battery cell, such as the length and / or width of the battery cell, the ends of the second core 2 extend beyond the ends of the first core 1, forming a blank area on the second core 2. The first and second cores 1 and 2 are connected by an adhesive layer 3. A stepped junction is formed between the ends of the first core 1 and the second core 2. In the first direction of the battery cell, the adhesive layer 3 extends beyond the ends of the first core 1. It should be noted that, depending on the shape of the battery cell after the first and second cores 1 and 2 are combined, the ends of the cores can be either one end or opposite ends. The ends of the cores include at least the end faces of the cores and a portion of the lateral surface surrounding the end faces. The two cores are combined by bonding their electrode sheets of the same polarity via the adhesive layer 3.

[0040] The adhesive layer extends beyond the end of the smaller first core stack in the first direction, that is, the length and width directions of the battery cell. The entire bottom of the first core stack can be more firmly bonded to the second core stack through the adhesive layer to reduce and avoid the risk of displacement and slippage, thereby improving the safety and reliability of the battery.

[0041] In one exemplary embodiment, the adhesive layer 3 extends in the first direction of the battery cell. One approach is to extend the adhesive layer 3 beyond the additional layer 4 and cover the blank area on the surface of the second core stack 2. With this arrangement, the adhesive layer 3 in the blank area can strengthen its bond with the aluminum-plastic film during battery cell assembly, further enhancing battery safety.

[0042] In one embodiment, in the second direction of the battery cell, the orthographic projection area of ​​the adhesive layer 3 is 20%-100% of the orthographic projection area of ​​the second core stack 2 , inclusive.

[0043] With this arrangement, the larger the projection of the adhesive layer 3 in the second direction, the stronger the bond. It has been verified that if the projection is less than 20%, there is a risk of displacement and separation between the two stacked cores due to poor adhesion. If it is greater than 100%, although the bonding area with the aluminum-plastic film is large, the area is overmatched and cannot match the area of ​​the second stacked core 2, resulting in an uneven interface of the second stacked core 2 and resulting in defects in the battery appearance.

[0044] In one embodiment, in the second direction of the battery cell, the thickness of the adhesive layer 3 is h, and the thickness of the paste layer of the first and second core stacks 1 and 2 is H, where h≤H. The paste layer is the structure coated on the surface of the electrode pieces of the first and second core stacks 1 and 2.

[0045] In this configuration, the thickness of the adhesive layer 3 should be as small as possible to maximize the battery capacity, but its maximum thickness should not exceed H, otherwise it will waste too much space and reduce the battery capacity.

[0046] In one embodiment, in the width direction of the battery cell, the width of the first core stack 1 is 5%-95% of the width of the second core stack 2 , inclusive.

[0047] In the length direction of the battery cell, the length of the first core stack 1 is 5%-95% of the length of the second core stack 2, inclusive. The first direction mentioned above refers to the width direction or the length direction.

[0048] With this arrangement, the projection of the first core stack 1 completely falls onto the second core stack 2 in the second direction (i.e., the height direction). The stepped laminated battery formed by the two core stacks is designed to more flexibly utilize space and improve battery energy density. The aforementioned dimensional ratio range covers all current design requirements for laminated batteries. If this range is exceeded, the difference in size between the two core stacks is too large or too small. After accounting for manufacturing errors and the aluminum-plastic film coating, such a dimensional design does not meet the design concept of a stepped laminated battery.

[0049] Continuing from the above, in one embodiment, an additional layer 4 is provided on at least one side of the adhesive layer 3, and in the second direction of the battery cell, the orthographic projection of the end of the first core stack 1 on the additional layer 4 does not extend beyond the additional layer 4. The second direction is the height direction of the battery cell.

[0050] With this arrangement, the ends of the first core stack 1 are actually thinned when the first and second core stacks 1 and 2 are combined under pressure, resulting in a thickness difference with other areas. This weakens the pressure applied to the ends and prevents the desired pressure-leveling effect from being achieved. However, the present application compensates for this thickness difference by adding an additional layer 4, increasing the degree of pressure applied to the ends of the first core stack 1, improving the flatness of the steps in the laminated battery, and eliminating the poor interface between the electrodes. This solves the problem of poor interface between the electrodes at the junction of the laminated cores in the prior art, which leads to black spots and the risk of lithium deposition.

[0051] Herein, the first direction may be the width direction or the length direction of the battery cell, and the second direction may be the height direction of the battery cell. As shown in FIG. 2 to FIG. 4 , when pressurizing and leveling, pressure is generally applied along the height direction of the battery cell.

[0052] In an optional embodiment, the additional layer 4 is a partial structure of the wrapping 5. The wrapping 5 wraps around the end of the first core stack 1. In other words, the end of the first core stack 1 is wrapped with the wrapping 5, and the portion of the wrapping 5 between the first core stack 1 and the second core stack 2 serves as the additional layer 4. The wrapping 5 can be a wrapping paper of various materials commonly used in battery production.

[0053] With this arrangement, before the two core stacks are composited, the end of the first core stack 1 is encapsulated with glue, which not only thickens the area and improves the flatness of the battery interface, but also resists the deformation of the first core stack 1 in the first direction and prevents the powder loss of the pole piece of the first core stack 1 causing a short circuit, thereby improving battery safety.

[0054] Furthermore, under the premise of the above embodiment, in the first direction of the battery cell, the distance between the inner edge of the encapsulation 5 and the edge of the first electrode sheet of the first core stack 1 is X1, the second electrode sheet of the first core stack 1 has an opposite polarity to the first electrode sheet, and the second electrode sheet extends beyond the first electrode sheet; where X1 ≥ 1 mm. It should be noted that the inner side of the encapsulation 5 is the side closest to the first core stack 1.

[0055] In this configuration, X1 being at least 1 mm can ensure that the covering body 5 completely covers the end of the first core stack 1. If X1 is less than 1 mm, due to the unavoidable machining errors in the actual production process, the covering body 5 may not completely cover the end of the first core stack 1, and the effect of thickening this area may not be achieved.

[0056] In an optional embodiment, the additional layer 4 is an independent structure applied on the adhesive layer 3; in this case, the additional layer 4 is a non-sticky material or structure, which is different from the material of the adhesive layer 3 and only serves to thicken the area. There are many raw materials available and the design options are more selective.

[0057] Alternatively, the additional layer 4 is an independent structure bonded to the adhesive layer 3. In this case, the additional layer 4 is made of a material or structure having adhesiveness, and is different from the material of the adhesive layer 3. Since the additional layer 4 is bonded to the adhesive layer 3, it not only thickens the area, but also makes the position of the additional layer 4 more stable.

[0058] Alternatively, the additional layer 4 and the adhesive layer 3 are integrally formed, and the additional layer 4 has a sticky surface. In this case, the additional layer 4 not only thickens the area but also, because it has a sticky surface, can adhere to the first core stack 1, making the position between the two core stacks most stable and reliable.

[0059] Furthermore, under the premise of the above embodiment, in the first direction of the battery cell, the distance between the inner edge of the additional layer 4 and the edge of the first pole piece of the first stacked core 1 is X1, and the distance between the outer edge of the additional layer 4 and the edge of the second pole piece of the first stacked core 1 is X2. The polarity of the first pole piece and the second pole piece are opposite, and the second pole piece extends beyond the first pole piece.

[0060] When the additional layer 4 is a separate structure applied or bonded to the adhesive layer 3, X1 and X2 satisfy the following conditions: 0.2 mm ≤ X1 ≤ 5 mm, and / or X2 ≥ 0.2 mm. This setting ensures that X1 and X2 are within the specified range, ensuring that the additional layer 4 completely covers the ends of the first core stack 1. If these values ​​exceed this range, the additional layer 4 may not completely cover the ends of the first core stack 1 due to unavoidable manufacturing errors in actual production processes, thus failing to achieve the desired effect of thickening this area.

[0061] When the additional layer 4 and the adhesive layer 3 are integrally formed, X1 and X2 satisfy the following requirements: X1 ≥ 1 mm; and / or X2 ≥ 1 mm. This setting ensures that X1 and X2 are within the specified range, ensuring that the additional layer 4 completely covers the ends of the first core stack 1. If these ranges are exceeded, due to unavoidable manufacturing errors in actual production processes, the additional layer 4 may not completely cover the ends of the first core stack 1, thus failing to achieve the desired thickening effect in this area.

[0062] It should be noted that the inner side of the additional layer 4 refers to the side of the additional layer 4 covered by the first core stack 1, and the outer side of the additional layer 4 refers to the side exposed in the blank area outside the first core stack 1. For example, the first electrode is a positive electrode, and the second electrode is a negative electrode.

[0063] In a specific embodiment, the specific form of the additional layer 4 as an independent structure can be the following situations.

[0064] The additional layer 4 comprises at least one of a separator cut body and a ceramic sprayed body. When the additional layer 4 is a separator cut body, it can be obtained by cutting separators commonly used in battery production, which is easily available and low-cost. The ceramic sprayed body can be obtained by directly spraying insulating ceramic onto the end of the first core stack 1. Spraying ceramic is also a commonly used process in battery production, which is easy to implement and low-cost.

[0065] Alternatively, the additional layer 4 includes a thickened paste layer formed on the paste layer of the second core stack 2. The paste layer is a structure coated on the surface of the pole piece. In this way, the paste layer of the second core stack 2 located at the end of the first core stack 1 can be thickened, which reduces the process cost.

[0066] Alternatively, additional layer 4 comprises adhesive tape bonded to adhesive layer 3. The adhesive tape is made of at least one of PP (polypropylene), PET (polyethylene terephthalate), PE (polyethylene), and PI (polyimide). The adhesive tape is bonded to the ends of the first stacked cores 1, ensuring strong positional stability and enabling easy operation and implementation.

[0067] In addition to the above-mentioned feasible methods, the additional layer 4 can be in any form as long as it has a non-conductive structure or material with increased thickness.

[0068] In another specific embodiment, the additional layer 4 and the adhesive layer 3 are integrally formed. The adhesive layer 3 includes a base layer and adhesive layers laminated on both sides of the base layer, and the additional layer 4 is a localized protrusion integral with the adhesive layer. This arrangement allows the additional layer 4 and the adhesive layer 3 to be designed as an integrated double-sided adhesive structure, which is directly applied to the second core stack 2, reducing the number of process steps required during the pressurized lamination of the core stack.

[0069] In another optional embodiment, regarding the extension degree of the adhesive layer 3 in the first direction of the battery cell, one way can be that the adhesive layer 3 exceeds the additional layer 4 and covers the blank area on the surface of the second core stack 2; with this arrangement, when the battery cell is assembled, the adhesive layer 3 in the blank area can strengthen the bonding effect with the aluminum-plastic film, further enhancing the safety of the battery.

[0070] Alternatively, another way may be that the edge of the adhesive layer 3 is flush with the edge of the additional layer 4; such an arrangement can save the material cost of the adhesive layer 3 to the greatest extent.

[0071] Based on the above-mentioned battery cell, the embodiment of the present application further provides a battery, which includes the above-mentioned battery cell. Since the battery includes the above-mentioned battery cell, the beneficial effects of the battery cell can be found in the above content and will not be repeated here.

[0072] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0073] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0074] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0075] 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 be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0076] 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 illustrate the technical solutions and cannot be used to limit the scope of protection of the present application.

[0077] The above description has been provided 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 a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A battery cell, characterized in that: The invention comprises a first core stack (1) and a second core stack (2) which are stacked in layers, wherein in a first direction of the battery core, an end of the second core stack (2) exceeds an end of the first core stack (1), and the first core stack (1) and the second core stack (2) are connected via an adhesive layer (3); wherein: In a first direction of the battery core, the adhesive layer (3) exceeds an end of the first core stack (1).

2. The battery cell according to claim 1, characterized in that: In a first direction of the battery core, the adhesive layer (3) covers a blank area on the surface of the second core stack (2), the first direction being the length direction or the width direction of the battery core.

3. The battery cell according to claim 1 or 2, characterized in that: In the second direction of the battery core, the orthographic projection area of ​​the adhesive layer (3) is 20%-100% of the orthographic projection area of ​​the second stacked core (2).

4. The battery cell according to any one of claims 1 to 3, characterized in that: In the second direction of the battery core, the thickness of the adhesive layer (3) is h, the thickness of the paste layer of the first stacked core (1) and the second stacked core (2) is H, and h≤H.

5. The battery cell according to any one of claims 1 to 4, characterized in that: In the width direction of the battery core, the width of the first stacked core (1) is 5%-95% of the width of the second stacked core (2).

6. The battery cell according to any one of claims 1 to 5, characterized in that: In the length direction of the battery core, the length of the first stacked core (1) is 5%-95% of the length of the second stacked core (2).

7. The battery cell according to any one of claims 1 to 6, characterized in that: An additional layer (4) is provided on at least one side of the adhesive layer (3); in a second direction of the battery core, the orthographic projection of the end of the first core stack (1) on the additional layer (4) does not exceed the additional layer (4); the second direction is the height direction of the battery core.

8. The battery cell according to claim 7, characterized in that: In the first direction of the battery core, the adhesive layer (3) exceeds the additional layer (4) or the adhesive layer (3) is flush with the edge of the additional layer (4).

9. The battery cell according to claim 7 or 8, characterized in that: The additional layer (4) is a local structure of a coating (5), and the coating (5) is coated on the end of the first stacked core (1).

10. The battery cell according to claim 7 or 8, characterized in that: The additional layer (4) is an independent structure laid on the adhesive layer (3).

11. The battery cell according to claim 7 or 8, characterized in that: The additional layer (4) is an independent structure bonded to the bonding layer (3).

12. The battery cell according to claim 7 or 8, characterized in that: The additional layer (4) and the adhesive layer (3) are an integral structure, and the additional layer (4) has a sticky surface.

13. The battery cell according to any one of claims 7 to 12, characterized in that: The additional layer (4) includes at least one of a diaphragm cut body and a ceramic sprayed body.

14. The battery cell according to any one of claims 7 to 12, characterized in that: The additional layer (4) comprises a paste thickening layer formed on the paste layer of the second laminated core (2).

15. The battery cell according to any one of claims 7 to 12, characterized in that: The additional layer (4) comprises adhesive tape bonded to the adhesive layer (3).

16. The battery cell according to claim 7 or 8, characterized in that: The bonding layer (3) comprises a base layer and a glue layer composited on both side surfaces of the base layer, and the additional layer (4) is a local protrusion integral with the glue layer.

17. The battery cell according to claim 9, characterized in that: In the first direction of the battery core, the distance between the inner edge of the sheath (5) and the edge of the first pole piece of the first stacked core (1) is X1, the second pole piece of the first stacked core (1) has a polarity opposite to that of the first pole piece, and the second pole piece extends beyond the first pole piece; wherein X1≥1mm.

18. The battery cell according to claim 7, characterized in that: In the first direction of the battery core, the distance between the inner edge of the additional layer (4) and the edge of the first pole piece of the first stacked core (1) is X1, the distance between the outer edge of the additional layer (4) and the edge of the second pole piece of the first stacked core (1) is X2, the polarity of the first pole piece is opposite to that of the second pole piece, and the second pole piece exceeds the first pole piece; wherein, The additional layer (4) is an independent structure laid or bonded on the bonding layer (3), 0.2 mm ≤ X1 ≤ 5 mm, and / or X2 ≥ 0.2 mm.

19. The battery cell according to claim 7, characterized in that: In the first direction of the battery core, the distance between the inner edge of the additional layer (4) and the edge of the first pole piece of the first stacked core (1) is X1, the distance between the outer edge of the additional layer (4) and the edge of the second pole piece of the first stacked core (1) is X2, the polarity of the first pole piece is opposite to that of the second pole piece, and the second pole piece exceeds the first pole piece; wherein, The additional layer (4) and the adhesive layer (3) are an integral structure, X1≥1mm, and / or X2≥1mm.

20. A battery, characterized in that: Comprising the battery cell as claimed in any one of claims 1 to 19.

Images