Battery, gluing device and battery device

Abstract

The utility model relates to the technical field of batteries, and provides a battery, a gluing device and a battery device, the battery comprises a plurality of pole pieces, a diaphragm and glue, and the plurality of pole pieces comprise positive pole pieces and negative pole pieces; the diaphragm is positioned between the positive plate and the negative plate, the diaphragm comprises a first side surface and a second side surface which are opposite to each other, the first side surface and the second side surface respectively comprise a coating area and a non-coating area which are adjacently arranged, and at least partial areas of the coating area in the first side surface and the non-coating area in the second side surface are oppositely arranged; at least partial areas of the coating area in the second side surface and the non-coating area in the first side surface are oppositely arranged; the glue is adhered between the coating area and the pole piece; wherein the thickness of the glue is less than or equal to 20 microns. On one hand, the battery can apply a small amount of glue to realize the adhesion of the pole piece and the diaphragm; and on the other hand, the battery cell formed by bonding the diaphragm and the pole piece has relatively small thickness, so that the energy density of the battery can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery, a glue coating device and a battery device. Background Art

[0002] In the related art, a battery cell may include positive and negative electrode sheets and a separator located between the positive and negative electrode sheets. The separator is bonded to the positive and negative electrode sheets respectively by double-sided gluing. However, the amount of glue applied to the separator is large, and the thickness of the battery cell formed by the separator and the electrode sheets is large.

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

[0004] The utility model provides a battery, which can improve the technical problems that the amount of glue coating on the diaphragm is large and the thickness of the battery core formed by the diaphragm and the pole piece is large.

[0005] Battery Included:

[0006] A plurality of pole pieces, including a positive pole piece and a negative pole piece;

[0007] A diaphragm, the diaphragm is located between the positive electrode sheet and the negative electrode sheet, the diaphragm includes a first side surface and a second side surface opposite to each other, the first side surface and the second side surface both include a coated area and a non-coated area disposed adjacent to each other, the coated area in the first side surface and at least a portion of the non-coated area in the second side surface are disposed opposite to each other, and the coated area in the second side surface and at least a portion of the non-coated area in the first side surface are disposed opposite to each other;

[0008] Glue, bonding between the coating area and the pole piece;

[0009] The thickness of the glue is less than or equal to 20 μm.

[0010] In the related art, after the two sides of the diaphragm are coated with glue and hot-pressed with the pole pieces, the overall thickness of the diaphragm is the thickness of the diaphragm plus the thickness of the glue layer on both sides. The utility model sets non-coating areas on both sides of the diaphragm, and the coating area in the first side and at least part of the non-coating area in the second side are arranged relative to each other, and the coating area in the second side and at least part of the non-coating area in the first side are arranged relative to each other. After the diaphragm is bonded to the pole piece, when the battery cell is hot-pressed, the glue in the coating area on the same side of the diaphragm extends to the non-coating area on the same side, and simultaneously approaches the non-coating area on the other side of the diaphragm, and the final thickness of the glue is ≤20μm. Compared with the related art, the overall thickness of the battery cell in the utility model is also smaller, so that the energy density of the battery can be improved. In addition, the utility model can also reduce the amount of glue used.

[0011] The utility model also provides a glue coating device, which is used to coat glue on the diaphragm, the diaphragm includes a first side surface and a second side surface opposite to each other, and the glue coating device includes:

[0012] A first roller, the first roller is used to apply glue to a first side of the diaphragm;

[0013] a second roller, the second roller being used for applying glue to the second side surface of the diaphragm;

[0014] The axial directions of the first roller and the second roller both extend along the first direction, and the first roller and the second roller are distributed in the second direction, and the first direction and the second direction intersect;

[0015] The outer peripheral surfaces of the first roller and the second roller both include a glue storage area and a non-glue storage area distributed along the first direction, and the glue storage area of ​​the first roller and the glue storage area of ​​the second roller are staggered in the first direction.

[0016] The glue coating device can coat glue on the diaphragm in the battery.

[0017] The utility model also provides a battery device, which includes the battery mentioned above.

[0018] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to better understand the present disclosure, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. In addition, in the drawings, the same reference numerals represent the same or similar components in each drawing.

[0020] in:

[0021] Figure 1 This is a schematic diagram of a portion of the structure of a battery cell before hot pressing in an exemplary embodiment of the battery disclosed herein;

[0022] Figure 2 This is a schematic diagram of a portion of the structure of a battery cell after hot pressing in an exemplary embodiment of the battery disclosed herein;

[0023] Figure 3 It is a schematic structural diagram of two sides of a separator in an exemplary embodiment of the battery disclosed in the present invention;

[0024] Figure 4 It is a structural schematic diagram of an exemplary embodiment of the glue coating device disclosed in the present invention;

[0025] Figure 5It is a structural schematic diagram of an exemplary embodiment of the glue coating device disclosed in the present invention.

[0026] Description of reference numerals:

[0027] 11. Positive electrode sheet; 12. Negative electrode sheet; 2. Diaphragm; 21. First side; 22. Second side; 31. Coating area; 32. Non-coating area; 4. Glue; 41. Glue dispensing structure; 51. First roller; 52. Second roller; 61. Glue storage area; 62. Non-glue storage area; 7. Glue storage groove; 8. Glue circuit circulation system; 9. Scraper system. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0029] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0030] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0031] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to one or more "upper", "lower", or "inner", "outer" of another element, it can not only be directly connected to the "upper", "lower", "inner", "outer" of another element or elements, but can also be indirectly connected to the "upper", "lower", "inner", "outer" of another element or elements through an intermediate element.

[0032] like Figure 1-3 As shown, Figure 1 This is a schematic diagram of a portion of the structure of a battery cell before hot pressing in an exemplary embodiment of the battery disclosed herein. Figure 2 This is a schematic diagram of a portion of the structure of a battery cell after hot pressing in an exemplary embodiment of the battery disclosed herein. Figure 3 This is a schematic diagram of the structure of the two sides of the separator in an exemplary embodiment of the battery disclosed in the present invention. Figure 3 After the diaphragm is flattened, the second side surface is translated along the length direction of the diaphragm to obtain a comparison diagram of the first side surface and the second side surface.

[0033] The battery includes: a plurality of pole pieces, a diaphragm 2, and glue 4, wherein the plurality of pole pieces include a positive pole piece 11 and a negative pole piece 12; the diaphragm 2 is located between the positive pole piece 11 and the negative pole piece 12, the diaphragm 2 includes a first side surface 21 and a second side surface 22 opposite to each other, the first side surface 21 and the second side surface 22 both include a coated area 31 and a non-coated area 32 arranged adjacent to each other, at least a portion of the coated area 31 in the first side surface 21 and the non-coated area 32 in the second side surface 22 are arranged relative to each other, and at least a portion of the coated area 31 in the second side surface 22 and the non-coated area 32 in the first side surface 21 are arranged relative to each other; the glue 4 is bonded between the coated area 31 and the pole piece; wherein the thickness h of the glue is less than or equal to 20 μm.

[0034] In the related art, after the two sides of the diaphragm are coated with glue and hot-pressed with the pole piece, the overall thickness of the diaphragm is the thickness of the diaphragm plus the thickness of the glue layer on both sides. The utility model sets non-coating areas on both sides of the diaphragm 2, and the coating area in the first side 21 and at least part of the non-coating area in the second side 22 are arranged relative to each other, and the coating area in the second side 22 and at least part of the non-coating area in the first side 21 are arranged relative to each other. When the battery cell is hot-pressed after the diaphragm 2 is bonded to the pole piece, the glue 4 in the coating area on the same side of the diaphragm extends to the non-coating area on the same side, and simultaneously approaches the non-coating area on the other side of the diaphragm (such as Figure 1 As shown by the arrow in the middle, the final thickness of the glue is ≤20μm. Compared with the related art, the overall thickness of the battery cell in the utility model is also smaller, thereby improving the energy density of the battery. In addition, the utility model can also reduce the amount of glue used.

[0035] It should be noted that at least part of the coated area 31 in the first side 21 and the non-coated area 32 in the second side 22 are arranged relative to each other, which can be understood as at least part of the coated area 31 in the first side 21 and the non-coated area 32 in the second side 22 are located on both sides of the same part of the diaphragm. At least part of the coated area 31 in the second side 22 and the non-coated area 32 in the first side 21 are arranged relative to each other, which can be understood as at least part of the coated area 31 in the second side 22 and the non-coated area 32 in the first side 21 are located on both sides of the same part of the diaphragm.

[0036] In this exemplary embodiment, h may be equal to 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc.

[0037] In this exemplary embodiment, Figure 1-3 As shown, the first side surface 21 may include a plurality of coating areas 31, on which: the coating areas 31 and the non-coating areas 32 are alternately distributed in the width direction X of the diaphragm 2; and / or, the second side surface 22 includes a plurality of coating areas 31, on which: the coating areas 31 and the non-coating areas 32 are alternately distributed in the width direction X of the diaphragm 2. A plurality of coating areas 31 arranged at intervals may improve the bonding stability between the pole piece and the diaphragm 2. In addition, in this exemplary embodiment, the coating areas 31 on both sides of the diaphragm are distributed along the width direction of the diaphragm, and this arrangement may facilitate the coating of the glue on the diaphragm by a roller.

[0038] It should be understood that in other exemplary embodiments, the first side 21 may include only one coating area, and the second side 22 may include only one coating area. In addition, the multiple coating areas in the first side 21 and / or the second side 22 may also have other distribution modes, for example, the multiple coating areas in the first side 21 and / or the second side 22 may be distributed along the length direction of the diaphragm.

[0039] In this exemplary embodiment, Figure 1-3 As shown, the coating area 31 on the first side 21 and the coating area 31 on the second side 22 are alternately distributed in the width direction X of the diaphragm 2; the distance between the coating area 31 on the first side 21 and the coating area 31 on the adjacent second side 22 in the width direction X of the diaphragm 2 is a, the width of the diaphragm 2 is m, and a / m is 3% to 30%. a / m can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc. If a / m is too large, a will be too large, and the bonding strength between the electrode and the diaphragm 2 will be low. If a / m is too small, a will be too small, there will be more glue on both sides of the diaphragm 2, and the thickness of the battery cell will be larger. This exemplary embodiment sets a / m to an appropriate size, which can not only ensure the bonding strength between the diaphragm and the electrode, but also reduce the amount of glue used in the battery and the thickness of the chip.

[0040] In this exemplary embodiment, Figure 1-3As shown, the size of a single coating area 31 in the width direction X of the diaphragm 2 is b, the width of the diaphragm 2 is m, and b / m is 3% to 20%. b / m can be equal to 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc. b / m is too small, b is too small, the bonding strength between the pole piece and the diaphragm 2 is low, b / m is too large, b is too large, there is more glue on both sides of the diaphragm 2, and the thickness of the battery cell is large. This exemplary embodiment sets b / m to a suitable size, which can not only ensure the bonding strength between the diaphragm and the pole piece, but also reduce the amount of glue used in the battery and the thickness of the chip.

[0041] In this exemplary embodiment, the size of a single coating area 31 in the first side 21 in the width direction X of the diaphragm 2 and the size of a single coating area 31 in the second side 22 in the width direction X of the diaphragm 2 may be the same or different; on the same side of the diaphragm, the size of a single coating area 31 in the width direction X of the diaphragm 2 may be the same or different.

[0042] In this exemplary embodiment, the total area of ​​the coating area 31 in the first side 21 and the second side 22 is S1, the total area of ​​the first side 21 and the second side 22 of the diaphragm 2 is S2, and S1 / S2 is 20%-50%. S1 / S2 can be equal to 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, etc. If S1 / S2 is too small, the bonding strength between the pole piece and the diaphragm 2 is low; if S1 / S2 is too large, there is more glue on both sides of the diaphragm 2, and the thickness of the battery cell is large. In this exemplary embodiment, S1 / S2 is set to a suitable size, which can not only ensure the bonding strength between the diaphragm and the electrode, but also reduce the amount of glue used in the battery and the thickness of the chip.

[0043] In this exemplary embodiment, Figure 1-3 As shown, the glue 4 may include a plurality of glue dot structures 41, and the plurality of glue dot structures are bonded between the coating area 31 and the pole piece in a dot array arrangement. The glue dot structure 41 can further save glue and ensure the bonding strength between the pole piece and the diaphragm. It should be understood that in other exemplary embodiments, the glue can also be applied to the coating area in the form of a glue layer.

[0044] In this exemplary embodiment, the coating area can be defined by the area where the glue is located, that is, the area coated with glue is the coating area, and the area not coated with glue is the non-coating area.

[0045] In this exemplary embodiment, the positive electrode sheet includes a positive electrode collector and a positive electrode active material layer located on at least one side of the positive electrode collector, and the negative electrode sheet may include a negative electrode collector and a negative electrode active material layer located on at least one side of the negative electrode collector. The battery also includes a positive electrode ear and a negative electrode ear, the positive electrode ear is connected to the positive electrode collector in the positive electrode sheet, for example, the positive electrode ear can be formed by cutting the positive electrode collector material layer; the negative electrode ear is connected to the negative electrode collector in the negative electrode sheet, for example, the negative electrode ear can be formed by cutting the negative electrode collector material layer. The positive electrode active material of the lithium-ion battery can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode active material can be graphite, silicon, etc. During charging, lithium ions are separated from the positive electrode active material, move to the negative electrode active material through the electrolyte, and the lithium ions are embedded in the interlayer gaps of the carbon material to complete the charging process of the battery. During discharge, lithium ions are separated from the negative electrode active material, move to the positive electrode active material through the electrolyte, and complete the discharge process of the battery.

[0046] In this exemplary embodiment, the material of the diaphragm may be PP (polypropylene) or PE (polyethylene), etc. The glue may include one or more of silicone glue, polyurethane glue, acrylic glue, and hot melt glue.

[0047] It should be noted that a battery includes a cell and an electrolyte, and a battery is the smallest unit capable of performing electrochemical reactions such as charge / discharge. A cell refers to a unit formed by winding or laminating a stacked portion, wherein the stacked portion includes a first pole sheet, a separator, and a second pole sheet. When the first pole sheet is a positive pole sheet, the second pole sheet is a negative pole sheet. The polarities of the first pole sheet and the second pole sheet can be interchanged.

[0048] In this exemplary embodiment, the battery may be a lithium-ion battery. It should be understood that in other exemplary embodiments, the battery may also be a nickel-cadmium battery, a nickel-metal hydride battery, a lithium polymer battery, a sodium-ion battery, a solid-state battery, etc.

[0049] In other exemplary embodiments, the battery may be a square battery, that is, the battery may be a quadrangular prism-type battery. The quadrangular prism-type battery mainly refers to a battery having a prism-shaped appearance, but does not strictly limit whether each side of the prism must be a straight line in the strict sense, and the corners between the sides are not necessarily right angles, and may be arc transitions.

[0050] The battery can be a laminated battery, which is not only convenient to group, but also can be processed to obtain a longer battery. Specifically, the battery cell is a laminated battery cell, which has a first pole piece stacked on top of each other, a second pole piece with electrical properties opposite to the first pole piece, and a diaphragm sheet arranged between the first pole piece and the second pole piece, so that multiple pairs of first pole pieces and second pole pieces are stacked to form a laminated battery cell.

[0051] Alternatively, the battery may be a wound battery, that is, a first pole sheet, a second pole sheet with electrical properties opposite to the first pole sheet, and a diaphragm sheet arranged between the first pole sheet and the second pole sheet are wound to obtain a wound battery cell.

[0052] like Figure 4 The figure is a schematic diagram of the structure of an exemplary embodiment of the glue coating device disclosed in the present invention. The glue coating device is used to coat glue on the diaphragm, and the diaphragm includes a first side and a second side opposite to each other. The glue coating device includes: a first roller 51 and a second roller 52, wherein the first roller 51 is used to coat glue on the first side of the diaphragm; and the second roller 52 is used to coat glue on the second side of the diaphragm; wherein the axial directions of the first roller 51 and the second roller 52 both extend along the first direction X, and the first roller 51 and the second roller 52 are distributed in the second direction Y, and the first direction X and the second direction Y intersect, for example, the first direction X and the second direction Y can be perpendicular; the outer peripheral surfaces of the first roller 51 and the second roller 52 both include a glue storage area 61 and a non-glue storage area 62 distributed along the first direction X, and the glue storage area 61 of the first roller 51 and the glue storage area 61 of the second roller 52 are staggered in the first direction X.

[0053] When the diaphragm passes through the gap between the first roller 51 and the second roller 52, the first roller 51 and the second roller 52 can rotate to apply glue to both sides of the diaphragm. The gluing device can be used to manufacture the above-mentioned battery.

[0054] In this exemplary embodiment, Figure 4 As shown, the glue storage area 61 of the first roller 51 is formed with a plurality of glue storage grooves 7 distributed in an array, and the glue storage area of ​​the second roller 52 is formed with a plurality of glue storage grooves 7 distributed in an array. The glue storage grooves 7 can store a certain amount of glue, and when the outer peripheral surfaces of the first roller 51 and the second roller 52 move relative to the diaphragm, the glue in the glue storage grooves 7 can be coated on the diaphragm. It should be understood that in other exemplary embodiments, the glue storage area can also be formed by strip-shaped glue storage grooves, and the strip-shaped glue storage grooves can be arranged around the circumference of the roller or parallel to the axial direction of the roller.

[0055] like Figure 5 FIG. 2 is a schematic diagram of another exemplary embodiment of the glue coating device of the present disclosure. The glue coating device further includes: a glue circuit circulation system 8 and a scraper system 9. The glue circuit circulation system 8 is connected to the first roller 51 and the second roller 52. The glue circuit circulation system 8 can be used to provide glue to the first roller 51 and the second roller 52. The scraper system 9 is used to scrape glue off the outer peripheral surface of the first roller 51 and the second roller 52.

[0056] The exemplary embodiment further provides a battery device, which is a battery module or a battery pack.

[0057] The battery module includes a plurality of batteries, which may be square batteries, and the battery module may further include end plates and side plates, which are used to fix the plurality of batteries. The batteries may be cylindrical batteries, which may be arranged on a support plate to form a battery module.

[0058] The battery pack includes a plurality of batteries and a box body, and the box body is used to fix the plurality of batteries.

[0059] It should be noted that the battery pack includes a battery, and the battery may be multiple, and the multiple batteries are arranged in the box. Among them, the multiple batteries can be installed in the box after forming a battery module. Alternatively, the multiple batteries can be directly arranged in the box, that is, there is no need to group the multiple batteries, and the box is used to fix the multiple batteries.

[0060] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing what is disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered merely as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0061] The drawings in the present disclosure only relate to the structures involved in the present disclosure, and other structures may refer to the usual design. In the absence of conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other to obtain new embodiments. It should be understood by those of ordinary skill in the art that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and should be included in the scope of the claims of the present disclosure.

[0062] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A battery, characterized in that: The battery comprises: A plurality of pole pieces, wherein the plurality of pole pieces include a positive pole piece (11) and a negative pole piece (12); A diaphragm (2), the diaphragm (2) being located between the positive electrode sheet (11) and the negative electrode sheet (12), the diaphragm (2) comprising a first side surface (21) and a second side surface (22) opposite to each other, the first side surface (21) and the second side surface (22) both comprising a coated area (31) and a non-coated area (32) arranged adjacent to each other, the coated area (31) in the first side surface (21) and at least a portion of the non-coated area (32) in the second side surface (22) being arranged opposite to each other, and the coated area (31) in the second side surface (22) and at least a portion of the non-coated area (32) in the first side surface (21) being arranged opposite to each other; Glue (4), bonded between the coating area (31) and the pole piece; Wherein, the thickness of the glue (4) is less than or equal to 20 μm.

2. The battery according to claim 1, characterized in that The first side surface (21) comprises a plurality of the coated areas (31), and on the first side surface (21): the coated areas (31) and the non-coated areas (32) are alternately distributed in sequence in the width direction of the diaphragm (2); And / or, the second side surface (22) comprises a plurality of the coated areas (31), and on the second side surface (22): the coated areas (31) and the non-coated areas (32) are alternately distributed in sequence in the width direction of the diaphragm (2).

3. The battery according to claim 1 or 2, characterized in that: The coating area (31) on the first side surface (21) and the coating area (31) on the second side surface (22) are alternately distributed in sequence in the width direction of the diaphragm (2); The distance between the coating area (31) on the first side surface (21) and the coating area (31) on the adjacent second side surface (22) in the width direction of the diaphragm (2) is a, the width of the diaphragm (2) is m, and a / m is 3% to 30%.

4. The battery according to claim 1 or 2, characterized in that: The dimension of a single coating area (31) in the width direction of the diaphragm (2) is b, the width of the diaphragm (2) is m, and b / m is 3% to 20%.

5. The battery according to claim 1 or 2, characterized in that: The total area of ​​the coating region (31) on the first side (21) and the second side (22) is S1, the total area of ​​the first side (21) and the second side (22) of the diaphragm (2) is S2, and S1 / S2 is 20%-50%.

6. The battery according to claim 1 or 2, characterized in that: The glue (4) comprises a plurality of glue dot structures (41), and the plurality of glue dot structures (41) are bonded between the coating area (31) and the pole piece in a dot array arrangement.

7. A glue coating device, characterized in that: The glue coating device is used to coat glue on the diaphragm, the diaphragm includes a first side surface and a second side surface opposite to each other, and the glue coating device includes: a first roller (51), the first roller (51) being used for applying glue to a first side surface of the diaphragm; a second roller (52), the second roller (52) being used for applying glue to the second side surface of the diaphragm; The axial directions of the first roller (51) and the second roller (52) both extend along a first direction (X), and the first roller (51) and the second roller (52) are distributed in a second direction (Y), and the first direction (X) and the second direction (Y) intersect; The outer peripheral surfaces of the first roller (51) and the second roller (52) both include a glue storage area (61) and a non-glue storage area (62) distributed along a first direction (X), and the glue storage area (61) of the first roller (51) and the glue storage area (61) of the second roller (52) are staggered in the first direction (X).

8. The gluing device according to claim 7, characterized in that: The glue storage area (61) of the first roller (51) is formed with a plurality of glue storage grooves (7) distributed in an array, and the glue storage area (61) of the second roller (52) is formed with a plurality of glue storage grooves (7) distributed in an array.

9. The gluing device according to claim 7, characterized in that: The glue coating device also includes: a glue circuit circulation system (8), the glue circuit circulation system (8) connecting the first roller (51) and the second roller (52), the glue circuit circulation system (8) being used to provide glue to the first roller (51) and the second roller (52); A scraper system (9), wherein the scraper system (9) is used to scrape off the glue on the outer peripheral surfaces of the first roller (51) and the second roller (52).

10. A battery device, characterized in that: The battery device comprises the battery according to any one of claims 1 to 6.

Images