Battery

Abstract

The invention relates to the technical field of battery safety, and particularly provides a battery which comprises a stacked core, a first bonding piece and a second bonding piece. The laminated core comprises a positive plate, a negative plate and a diaphragm; the stack core comprises a main body part and an extension part; the extension part is formed by the part of the diaphragm exceeding the negative plate; the main body part is provided with a first surface, a second surface, a fifth surface, a sixth surface, a seventh surface and an eighth surface; the extending part is provided with a third surface and a fourth surface; the first bonding piece is at least bonded to the first surface and the third surface, and the second bonding piece is bonded to the first surface, the seventh surface and the second surface; the total area of the first surface and the second surface is S1, the total overlapping area of the bonding piece and the first surface and the second surface is S2, and S2 / S1 is larger than or equal to 6% and smaller than or equal to 25%. The bonding piece can apply inward constraint to the laminated core, so that the layering phenomenon of the pole pieces is avoided; the total overlapping area of the bonding piece, the first surface and the second surface is moderate, so that the bonding effect can be improved, and the laminated core cannot be covered too much.

Description

Technical Field

[0001] The present application relates to the technical field of battery safety and specifically proposes a battery. Background Art

[0002] Currently, stacked batteries with silicon-doped anodes are becoming increasingly popular in the market due to their excellent rate performance and high energy density. However, the silicon-doped anode expands significantly during charge and discharge, which can cause delamination of the stacked core and lead to lithium deposition. Furthermore, the lack of a separator can also lead to localized delamination during drop and roller tests. Summary of the Invention

[0003] The purpose of this application is to solve at least some of the technical problems mentioned above, and this purpose is achieved through the following technical solutions:

[0004] The present application provides a battery comprising a stacked core and an adhesive. The stacked core comprises a positive electrode sheet, a negative electrode sheet, and a separator stacked in a first direction. The stacked core comprises a main body and an extension located at at least one side edge of the main body, the extension being formed by a portion of the separator extending beyond the edge of the negative electrode sheet. The main body has a first surface and a second surface opposing each other in the first direction. The extension has a third surface and a fourth surface opposing each other in the first direction. A tab is provided at one end of the stacked core in a second direction. The stacked core has a fifth surface and a sixth surface opposing each other in the second direction, the tab extending from the fifth surface. The stacked core has a seventh surface and an eighth surface opposing each other in a third direction. The first, second, and third directions are perpendicular to each other. The adhesive comprises a first adhesive and a second adhesive, the first adhesive being bonded to at least the first and third surfaces, and the second adhesive being bonded to the first, seventh, and second surfaces. The total area of ​​the first and second surfaces is S1, and the total overlapping area of ​​the adhesive with the first and second surfaces is S2, satisfying the condition 6% ≤ S2 / S1 ≤ 25%.

[0005] In some embodiments, the first adhesive is bonded to the first surface, the third surface, the fifth surface, and the second surface, and satisfies 6%≤S2 / S1≤15%.

[0006] In some embodiments, at least one end of the second adhesive member along the second direction extends beyond the laminated core or is flush with an end of the laminated core.

[0007] In some embodiments, the adhesive further includes a third adhesive and a fourth adhesive, the third adhesive is bonded to the first surface, the sixth surface, and the second surface, and the fourth adhesive is bonded to the first surface, the eighth surface, and the second surface.

[0008] In some embodiments, the orthographic projections of the second adhesive and the fourth adhesive along the third direction at least partially overlap, and a dimension of the overlapping portion along the second direction is C, and C≧10 mm.

[0009] In some embodiments, the negative electrode sheet includes a negative electrode active layer, the mass content of silicon in the negative electrode active layer is W, and satisfies 2%≤W≤80%; when 2%≤W≤10%, it satisfies 6%≤S2 / S1≤12%; when 10%≤W≤80%, it satisfies 12%≤S2 / S1≤25%.

[0010] In some embodiments, the adhesive member includes a substrate and an adhesive layer, the thickness of the adhesive member is d, the thickness of the substrate is d1, the thickness of the adhesive layer is d2, and satisfies 8μm≤d≤24μm, and / or 6μm≤d1≤15μm, and / or 2μm≤d2≤10μm; and / or the adhesive layer includes a rubber adhesive.

[0011] In some embodiments, two tabs are extended from the fifth surface, a distance between the two tabs is D1, a dimension of the first adhesive along the third direction is L1, and L1≤0.5D1 is satisfied.

[0012] In some embodiments, the end portion of the second adhesive member along the second direction is bonded to the extension portion, and a bonding dimension of the two along the second direction is K, and satisfies 0.25 mm ≤ K ≤ 2 mm.

[0013] In some embodiments, the adhesive member is provided with a plurality of micropores, the total area of ​​the micropores is S3, the total area of ​​the adhesive member is S, and 2%≤S3 / S≤20% is satisfied.

[0014] The technical solution proposed in this application has at least the following technical effects:

[0015] In the present application, a first adhesive and a second adhesive are provided on the stacked core, which can exert an inward constraint on the stacked core, suppress the expansion force generated by the electrode, and avoid stratification of the electrode; in addition, the total overlapping area of ​​the adhesive and the first surface and the second surface is moderate, which can not only improve the bonding effect and enhance the overall stability of the stacked core, but also the adhesive will not have excessive coverage of the stacked core, thereby avoiding hindering the electrolyte from infiltrating the stacked core and affecting the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to better integrate the contents shown in the drawings with the contents described in the specific embodiments, a brief introduction to the drawings is given below. It is understood that the drawings mentioned below are only schematic illustrations of the relevant technical solutions and some embodiments of the technical solutions of this application. Without making any creative efforts, those skilled in the art can also create drawings showing other embodiments.

[0017] Specifically, the annotations to the drawings of the specification are as follows:

[0018] Figure 1 is an axonometric diagram of a first battery according to some embodiments of the present application;

[0019] Figure 2 is an axonometric diagram of a second battery according to some embodiments of the present application;

[0020] Figure 3 is an axonometric diagram of a third battery described in some embodiments of the present application;

[0021] Figure 4 is an axonometric diagram of a fourth battery described in some embodiments of the present application;

[0022] Figure 5 is an axonometric diagram of a fifth battery described in some embodiments of the present application;

[0023] Figure 6 This is a side view of a battery according to some embodiments of the present application.

[0024] Specifically, the annotations of the accompanying drawings are as follows:

[0025] 10. Stacked core; 101. First surface; 102. Second surface; 103. Fifth surface; 104. Sixth surface; 105. Seventh surface; 106. Eighth surface; 110. Positive electrode sheet; 120. Negative electrode sheet; 130. Separator; 20. Adhesive; 201. Adhesive portion; 210. First adhesive; 220. Third adhesive; 230. Fourth adhesive; 240. Second adhesive; 30. Tab; X, third direction; Y, second direction; Z, first direction. DETAILED DESCRIPTION

[0026] To make the contents of the embodiments of this application clearer, the following description will be made in conjunction with the accompanying drawings. It is understood that the contents mentioned below are only some of the embodiments of this application, and all embodiments are listed in detail. Therefore, without inventive work, other embodiments obtained based on the following embodiments fall within the scope of protection of this application.

[0027] It should be understood that the terms used herein are for the purpose of describing specific embodiments only and are not intended to strictly limit the technical solutions unless the context clearly indicates otherwise. For example, the use of "a," "an," and "the" to modify a feature does not exclude the possibility that the feature may be plural in other embodiments.

[0028] It should be understood that the terms "include," "comprising," and "having" are open-ended, indicating the presence of the stated features but not excluding the possibility of additional features in the embodiment. Similarly, when terms such as first, second, etc. are used herein to describe multiple features, they are merely used to distinguish one feature from another and do not imply a sequence or order unless the context clearly indicates otherwise.

[0029] It should be understood that, unless the context clearly indicates otherwise, the terms "disposed," "connected," and "installed" should be interpreted broadly. For example, they may refer to fixed, detachable, or integral connections; they may be directly connected or indirectly connected through a medium. Those skilled in the art will understand the specific meanings of these terms in the context of the text based on the specific circumstances.

[0030] In addition, for the convenience of description, the text will use terms of spatial relative relationships to illustrate the position of one feature relative to another feature, such as "inside", "outside", "end", "side", "upper", "middle", "lower", "high", "lower", "axial", "circumferential", "radial", "horizontal", "vertical", "first direction", "second direction", etc. It can be understood that the spatial relative relationship between two features should include other specific situations in addition to those shown in the drawings of the specification.

[0031] The embodiments of the present application are described below with reference to the accompanying drawings.

[0032] Reference Figures 1 to 6 The embodiment of the present application provides a battery comprising a stacked core 10 and an adhesive 20. The stacked core 10 comprises a positive electrode sheet 110, a negative electrode sheet 120, and a separator 130 stacked along a first direction Z; the stacked core 10 comprises a main body and an extension located at at least one side edge of the main body, the extension being formed by a portion of the separator 130 extending beyond the edge of the negative electrode sheet 120; the main body has a first surface 101 and a second surface 102 opposite to each other along the first direction Z; the extension has a third surface and a fourth surface opposite to each other along the first direction Z; a tab 30 is provided at one end of the stacked core 10 along the second direction Y, and the stacked core 10 has a fifth surface 103 and a sixth surface 104 opposite to each other along the second direction Y, the tab 30 extending from the fifth surface 103. The stacked core 10 has a seventh surface 105 and an eighth surface 106 that are opposite to each other along a third direction X. The first direction Z, the second direction Y, and the third direction X are perpendicular to each other. The adhesive 20 includes a first adhesive 210 and a second adhesive 240. The first adhesive 210 is bonded to at least the first surface 101 and the third surface, and the second adhesive 240 is bonded to the first surface 101, the seventh surface 105, and the second surface 102. The total area of ​​the first surface 101 and the second surface 102 is S1, and the total overlapping area of ​​the adhesive 20 with the first surface 101 and the second surface 102 is S2, and the condition 6% ≤ S2 / S1 ≤ 25% is satisfied.

[0033] In this embodiment, a first adhesive 210 and a second adhesive 240 are provided on the stacked core 10, which can exert an inward constraint on the stacked core 10, suppress the expansion force generated by the electrode, and avoid delamination of the electrode. In addition, the total overlapping area between the adhesive 20 and the first surface 101 and the second surface 102 is moderate, which can not only improve the bonding effect and enhance the overall stability of the stacked core 10, but also the adhesive 20 will not have excessive coverage on the stacked core 10, thereby avoiding hindering the electrolyte from infiltrating the stacked core 10 and affecting the battery performance.

[0034] It can be understood that S2 / S1 can take any value among 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% or the range between any two values.

[0035] In some embodiments, reference Figures 1 to 5 The first adhesive 210 is bonded to the first surface 101 , the third surface 103 , the fifth surface 103 and the second surface 102 , and satisfies 6%≤S2 / S1≤15%.

[0036] In this embodiment, the first adhesive 210 is bonded to the first surface 101, the third surface 103, the fifth surface 103, and the second surface 102, providing a better binding effect on the stacked core 10. Therefore, the contact area between the adhesive 210 and the first and second surfaces 101, 102 can be smaller to improve electrolyte wetting. For example, S2 / S1 can be any value among 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%, or a range between any two values.

[0037] In some embodiments, reference Figures 1 to 5 At least one end of the second adhesive member 240 along the second direction Y extends beyond the stacked core 10 or is flush with the end of the stacked core 10 .

[0038] In this embodiment, the second adhesive 240 covers the end portion of the stacked core 10 along the second direction Y, which has a good bonding effect and further prevents the stacked core 10 from being delaminated.

[0039] Furthermore, in some embodiments, the overlapping area between the adhesive 20 and the first surface 101 is S21, and the overlapping area between the adhesive 20 and the second surface 102 is S22, satisfying the relationship 0.95 ≤ S21 / S22 ≤ 1.05. In this embodiment, the bonding area between the adhesive 20 and the first surface 101 and the second surface 102 is maintained as equal as possible, thereby ensuring the bond strength between the adhesive 20 and the stacked core 10 at both ends in the first direction Z. This prevents one end from becoming detached due to insufficient bond strength, thereby affecting the bond between the adhesive 20 and the stacked core 10 and causing the stacked core 10 to delaminate due to expansion.

[0040] In some embodiments, reference Figures 1 to 5 The adhesive member 20 further includes a third adhesive member 220 and a fourth adhesive member 230 . The third adhesive member 220 is bonded to the first surface 101 , the sixth surface 104 , and the second surface 102 . The fourth adhesive member 230 is bonded to the first surface 101 , the eighth surface 106 , and the second surface 102 .

[0041] In this embodiment, the adhesive member 20 further includes a third adhesive member 220 and a fourth adhesive member 230. The third adhesive member 220 is bonded to the first surface 101, the sixth surface 104, and the second surface 102, and the fourth adhesive member 230 is bonded to the first surface 101, the eighth surface 106, and the second surface 102, further enhancing the restraint effect on the stacked core 10 and preventing the stacked core 10 from delamination when it falls or is tested.

[0042] In some embodiments, reference Figures 1 to 5 The orthographic projections of the second adhesive 240 and the fourth adhesive 230 along the third direction X at least partially overlap, and a dimension of the overlapping portion along the second direction Y is C, and C≥10 mm.

[0043] In this embodiment, referring to Figure 1 、 Figure 2 、 Figure 4 and Figure 5 The fourth adhesive member 230 and the second adhesive member 240 are arranged correspondingly along the third direction X, referring to Figure 3 The fourth adhesive member 230 and the second adhesive member 240 are staggered in the third direction X. Specifically, there is a certain amount of projected overlap between the fourth adhesive member 230 and the second adhesive member 240 along the third direction X, and the overlap dimension is not less than 10 mm, thereby ensuring that the stacked core 10 is restrained relatively evenly at both ends in the third direction X and preventing the adhesive member 20 from having a weak position on the stacked core 10.

[0044] In some embodiments, reference Figures 1 to 5 The stacked core 10 is provided with a fourth adhesive 230 and a second adhesive 240 at both ends along the third direction X, respectively. There is at least one fourth adhesive 230 and second adhesive 240. The height of the stacked core 10 is H, the sum of the dimensions of all the fourth adhesives 230 along the second direction Y of the stacked core 10 is H1, and the sum of the dimensions of all the second adhesives 240 along the second direction Y of the stacked core 10 is H2, and 0.4H≤H1≤H and / or 0.4H≤H2≤H are satisfied.

[0045] In this embodiment, referring to Figures 1 to 3 , the fourth adhesive member 230 is provided with a reference Figure 4 and Figure 5 , there are two fourth adhesive members 230. Figures 1 to 3, the second adhesive member 240 is provided with a, reference Figure 4 and Figure 5 , there are two second adhesive members 240 , and the above are all desirable implementation methods.

[0046] Furthermore, in some embodiments, the first adhesive 210 and / or the third adhesive 220 are bonded to the separator 130 located in the middle of the stacked core 10 in the first direction Z; and / or the fourth adhesive 230 and / or the second adhesive 240 are bonded to the separators 130 located near the ends of the stacked core 10 in the first direction Z. This embodiment not only simplifies the manufacturing process but also enhances the restraining effect of the adhesive 20. Furthermore, the first adhesive 210 and / or the third adhesive 220 are bonded to the separator 130 in the middle, preventing short circuits caused by contact between the positive electrode 110 and the negative electrode 120 due to thermal shrinkage of the separator 130 under extreme conditions. The fourth adhesive 230 and / or the second adhesive 240 are bonded to the separators 130 at both ends, preventing safety issues caused by delamination between the positive electrode and the separator 130 in the single-sided region or thermal shrinkage of the separator 130 opposite the positive electrode in the single-sided region.

[0047] Furthermore, in some embodiments, adhesive members 20 are provided at least at one of the four corners of the stacked core 10. In this embodiment, the four corners of the stacked core 10 are relatively vulnerable compared to other locations during drops or extreme testing. Covering and securing these corners with adhesive members 20 provides cushioning and restraint, preventing damage to the corners that could cause battery safety issues.

[0048] In some embodiments, the negative electrode sheet 120 includes a negative electrode active layer, the mass content of silicon in the negative electrode active layer is W, and satisfies 2%≤W≤80%; when 2%≤W≤10%, it satisfies 6%≤S2 / S1≤12%; when 10%≤W≤80%, it satisfies 12%≤S2 / S1≤25%.

[0049] In this embodiment, the expansion of the negative active layer of the negative electrode sheet 120 is related to the mass content of silicon. Specifically, the higher the mass content of silicon in the negative active layer, that is, the larger W, the greater the expansion of the negative electrode sheet 120. Therefore, the adhesive 20 needs to apply a larger binding force, and the adhesive 20 needs to have a larger connection area with the first surface 101 and the second surface 102 of the stacked core 10, that is, S2 / S1 is larger.

[0050] Optionally, the negative electrode active layer includes a silicon-based material, and the silicon-based material in the negative electrode active layer is at least one of elemental silicon, silicon-carbon material, silicon-oxygen material, and silicon alloy. Further, the silicon-based material in the negative electrode active layer includes a silicon-carbon material, and the silicon-carbon material includes a porous carbon matrix, silicon grains located in the pores of the porous carbon matrix, and a carbon layer located on the surface of the porous carbon matrix; wherein the carbon layer is provided with openings corresponding to the pores of the porous carbon matrix. Specifically, the specific surface area of ​​the silicon-carbon material is 0.5m 2 / g to 10m 2 / g, and / or the particle size of the silicon-carbon material is 6 μm to 15 μm, and / or the powder resistivity of the silicon-carbon material is 0.1 Ω·cm to 1000 Ω·cm, and / or the mass content of silicon in the silicon-carbon material is 30% to 75%.

[0051] Furthermore, in some embodiments, the number of positive electrode sheets 110 layers is N1, and the number of adhesives 20 is N2, with N1 and N2 being positively correlated, and / or N1 and S2 / S1 being positively correlated; and / or 2 ≤ N2 ≤ 8. In this embodiment, a greater number of positive electrode sheets 110 layers in the stacked core 10 corresponds to a greater number of negative electrode sheets 120 layers, and the stacked core 10 expands more. Therefore, a greater number of adhesives 20 is required, and / or a greater connection area between the adhesives 20 and the stacked core 10 is required to provide sufficient binding force and prevent delamination of the stacked core 10. Furthermore, the number of adhesives 20, i.e., N2, should be moderate to ensure binding while minimizing electrolyte wetting. For example, N2 can be any value among 2, 3, 4, 5, 6, 7, 8, or a range between any two values. It should be noted that, the greater the number of adhesive members 20 , the more complex the gluing process will be and the longer the gluing time will be.

[0052] In some embodiments, the adhesive member 20 includes a substrate and an adhesive layer, the thickness of the adhesive member 20 is d, the thickness of the substrate is d1, the thickness of the adhesive layer is d2, and satisfies 8μm≤d≤24μm, and / or 6μm≤d1≤15μm, and / or 2μm≤d2≤10μm; and / or the adhesive layer includes a rubber adhesive.

[0053] In this embodiment, the total thickness of the adhesive 20, as well as the thickness of the substrate and adhesive layer thereon, should all be moderate. Specifically, d, d1, and d2 should all be moderate, so as to avoid excessive internal battery space occupation and reduced volumetric energy density while still ensuring connection strength and bonding effectiveness. For example, d can be any value or a range between any two of 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, or 24μm. d1 can be any value or a range between any two of 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm. d2 can be any value among 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, or a range between any two values.

[0054] Optionally, the substrate includes PET (high-temperature resistant polyester film), BOPP (biaxially oriented polypropylene film), PI (polyimide film), etc. The adhesive layer may be at least one of an acrylic adhesive and a rubber adhesive, with rubber adhesive being preferred. Specifically, rubber adhesives are more resistant to electrolytes and exhibit minimal changes in adhesive properties after prolonged immersion in electrolytes, thereby preventing degradation of the adhesive effect.

[0055] In some embodiments, reference Figures 1 to 5 Two tabs 30 are led out from the fifth surface 103 , the distance between the two tabs 30 is D1 , the dimension of the first adhesive 210 along the third direction X is L1 , and L1 ≤ 0.5D1 is satisfied.

[0056] In this embodiment, due to the obstruction of the tab 30, the size of the first adhesive 210 along the third direction X of the stacked core 10 cannot be too large; specifically, referring to Figure 1 、 Figure 2 、 Figure 4 and Figure 5 , the first adhesive member 210 is located between the two tabs 30, refer to Figure 3 The first adhesive member 210 is located on a side of one of the tabs 30 that is away from the other tab 30. It can be understood that one or more first adhesive members 210 may be provided.

[0057] In addition, in some embodiments, there is at least one third adhesive member 220, the dimension of the laminated core 10 along the third direction X is L, the sum of the dimensions of all third adhesive members 220 along the third direction X is L2, and 0.4L≤L2≤L is satisfied. Figures 1 to 4 , the third adhesive member 220 is provided with a reference Figure 5 , there are two third adhesive members 220, and the above are all desirable implementation methods.

[0058] In some embodiments, reference Figure 6 The end portion of the second adhesive member 240 along the second direction Y is bonded to the extension portion, and a bonding dimension of the two along the second direction Y is K, and satisfies 0.25 mm ≤ K ≤ 2 mm.

[0059] Specifically, refer to Figure 6 The fourth adhesive member 230 and / or the second adhesive member 240 extend beyond the diaphragm 130 from the first surface 101 and the second surface 102 respectively along the second direction Y, and the extending portions are bonded to each other to form a bonding portion 201, and the size of the bonding portion 201 along the second direction Y is K, and satisfies 0.25mm≤K≤2mm.

[0060] In this embodiment, the fourth adhesive member 230 and / or the second adhesive member 240 extend beyond the diaphragm 130 and adhere to each other to ensure a binding effect. The size of the adhesive portion 201 cannot be too large, otherwise it will affect the battery head space and reduce the volume energy density. It cannot be too small, otherwise the bonding strength will be low and it will easily come apart. Therefore, the size of the adhesive portion 201 should be moderate, that is, K should be moderate. For example, K can be any value among 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm, or a range between any two values.

[0061] In some embodiments, the adhesive member 20 is provided with a plurality of micropores, the total area of ​​the micropores is S3, the total area of ​​the adhesive member 20 is S, and 2%≤S3 / S≤20% is satisfied.

[0062] And / or, the micropores are all arranged at the parts where the adhesive 20 connects to the sides of the stacked core 10, or the area of ​​the micropores arranged at the parts where the adhesive 20 connects to the first surface 101 and the second surface 102 is smaller than the area of ​​the micropores arranged at the parts where the adhesive 20 connects to the sides of the stacked core 10.

[0063] It should be noted that increasing the restraining area of ​​the adhesive 20 may hinder the electrolyte infiltration effect, so it is necessary to drill holes in the adhesive 20. Specifically, in this embodiment, the total area of ​​the micropores cannot be too large, otherwise it will affect the structural strength of the adhesive 20; at the same time, the total area of ​​the micropores cannot be too small, otherwise it will not be able to increase the electrolyte infiltration effect. Therefore, the total area of ​​the micropores should be moderate, that is, S3 / S should be moderate. For example, S3 / S can be any value among 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range between any two values. It should be noted that the four sides of the stacked core 10 mainly serve as electrolyte infiltration, while the first surface 101 and the second surface 102 mainly serve as connections with the adhesive 20 . Therefore, the micropores need to be mainly provided on the four sides of the stacked core 10 .

[0064] It should be understood that the embodiments of the present application only illustrate the structure of the battery related to the improvements of the present application, but it does not mean that it does not have other structures. For example, the battery also includes a shell, an electrolyte, etc. Other structures will not be described one by one here.

[0065] In particular, the term "and / or" in this application should be understood as follows:

[0066] In the first case, the term “and / or” located between a first subject and a second subject includes any one of the following meanings: (1) only the first subject; (2) only the second subject; and (3) the first subject and the second subject.

[0067] In the second case, the term "and / or" between the last two entities in three or more entities means including at least any one of the entities. For example, "the first entity, the second entity and / or the third entity" has the same meaning as "the first entity and / or the second entity and / or the third entity", specifically including the following combinations: (1) only the first entity; (2) only the second entity; (3) only the third entity; (4) the first entity and the second entity without the third entity; (5) the first entity and the third entity without the second entity; (6) the second entity and the third entity without the first entity; and (7) the first entity, the second entity and the third entity;

[0068] In addition, the character “ / ” in this application indicates that the objects before and after it are in an “or” relationship.

[0069] Finally, although the above content describes the embodiments of the present application in conjunction with the accompanying drawings, those skilled in the art can also make various modifications and variations without departing from the concept of the present application, and such modifications and variations shall fall within the scope of protection of the present application.

Claims

1. A battery, characterized in that: include: A stacked core (10) comprises a positive electrode sheet (110), a negative electrode sheet (120) and a separator (130) stacked along a first direction (Z); the stacked core (10) comprises a main body and an extension located at at least one side edge of the main body, the extension being formed by a portion of the separator (130) extending beyond the edge of the negative electrode sheet (120); The main body has a first surface (101) and a second surface (102) opposite to each other along the first direction (Z); the extension has a third surface and a fourth surface opposite to each other along the first direction (Z); a tab (30) is provided at one end of the stacked core (10) along the second direction (Y); the stacked core (10) has a fifth surface (103) and a sixth surface (104) opposite to each other along the second direction (Y); the tab (30) is extended from the fifth surface (103); the stacked core (10) has a seventh surface (105) and an eighth surface (106) opposite to each other along the third direction (X); the first direction (Z), the second direction (Y) and the third direction (X) are perpendicular to each other; An adhesive member (20) comprising a first adhesive member (210) and a second adhesive member (240), wherein the first adhesive member (210) is bonded to at least the first surface (101) and the third surface, and the second adhesive member (240) is bonded to the first surface (101), the seventh surface (105), and the second surface (102); The total area of ​​the first surface (101) and the second surface (102) is S1, the total overlapping area of ​​the adhesive (20) and the first surface (101) and the second surface (102) is S2, and 6%≤S2 / S1≤25% is satisfied.

2. The battery according to claim 1, characterized in that The first adhesive (210) is bonded to the first surface (101), the third surface, the fifth surface (103) and the second surface (102), and satisfies 6%≤S2 / S1≤15%.

3. The battery according to claim 1, characterized in that At least one end of the second adhesive member (240) along the second direction (Y) extends beyond the stacked core (10) or is flush with an end of the stacked core (10).

4. The battery according to claim 1, characterized in that The adhesive member (20) further includes a third adhesive member (220) and a fourth adhesive member (230), wherein the third adhesive member (220) is bonded to the first surface (101), the sixth surface (104) and the second surface (102), and the fourth adhesive member (230) is bonded to the first surface (101), the eighth surface (106) and the second surface (102).

5. The battery according to claim 4, characterized in that The orthographic projections of the second adhesive component (240) and the fourth adhesive component (230) along the third direction (X) at least partially overlap, and the dimension of the overlapping portion along the second direction (Y) is C, and C≥10 mm is satisfied.

6. The battery according to claim 1, characterized in that The negative electrode sheet (120) comprises a negative electrode active layer, wherein the mass content of silicon in the negative electrode active layer is W and satisfies 2%≤W≤80%; when 2%≤W≤10%, 6%≤S2 / S1≤12% is satisfied; when 10%≤W≤80%, 12%≤S2 / S1≤25% is satisfied.

7. The battery according to claim 1, characterized in that The adhesive member (20) comprises a substrate and an adhesive layer, the thickness of the adhesive member (20) is d, the thickness of the substrate is d1, the thickness of the adhesive layer is d2, and the following conditions are satisfied: 8 μm ≤ d ≤ 24 μm, and / or 6 μm ≤ d1 ≤ 15 μm, and / or 2 μm ≤ d2 ≤ 10 μm; and / or the adhesive layer comprises a rubber adhesive.

8. The battery according to any one of claims 1 to 7, characterized in that The fifth surface (103) leads to two tabs (30), the distance between the two tabs (30) is D1, the dimension of the first adhesive (210) along the third direction (X) is L1, and L1≤0.5D1 is satisfied.

9. The battery according to claim 1, characterized in that The end portion of the second adhesive member (240) along the second direction (Y) is bonded to the extension portion, and a bonding dimension of the two along the second direction (Y) is K, and satisfies 0.25 mm ≤ K ≤ 2 mm.

10. The battery according to claim 1, characterized in that The adhesive member (20) is provided with a plurality of micropores, the total area of ​​the micropores is S3, the total area of ​​the adhesive member (20) is S, and 2%≤S3 / S≤20% is satisfied.

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