Battery case and battery

Abstract

The present invention discloses a battery case and a battery, in which the battery case is divided into a bottom cap and a sealing cap, and the sealing cap is divided into an outer contact layer, an insulating layer and an inner contact layer, the electrode contact part of the outer contact layer penetrates the insulating layer and the inner contact layer to electrically connect with one electrode of the battery cell, and the other electrode of the battery cell is electrically connected with the bottom cap, and the inner contact layer and the bottom cap can be welded to realize packaging of the battery cell, and the inner contact layer and the outer contact layer are insulated by the insulating layer, and the bottom cap is also insulated from the outer contact layer, so that the short circuit between the two electrodes of the battery cell can be prevented. Since the inner contact layer and the outer contact layer of the sealing cap are insulated in advance, there is no need to add an insulating film when assembling the sealing cap to the bottom cap, and it is only necessary to weld the inner contact layer and the bottom cap, which can simplify the packaging process of the battery and improve the packaging efficiency.

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and more particularly to a battery case and a battery. [Background technology]

[0002] In existing button batteries, the battery case is formed by connecting a positive electrode casing, a negative electrode casing, and an insulating plastic sleeve. To prevent the button battery from shorting, the positive electrode casing and the negative electrode casing must be insulated from each other. In related technologies, this insulation is achieved by providing an insulating film between the positive electrode casing and the negative electrode casing. In the related production process, the positive electrode casing and the negative electrode casing are pressed together with the insulating plastic sleeve to complete the sealing of the entire case, and the positive electrode casing and the negative electrode casing are then welded together. In the processing process, existing cases assembled only by pressing the positive electrode casing and the negative electrode casing together have poor sealing effect, resulting in frequent leakage of button battery fluid, and the installation of the insulating film is difficult, making the processing of button batteries more difficult and reducing processing efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] The main object of the present invention is to provide a battery case for a button battery that solves the technical problems of how to improve the processing efficiency and sealing performance of the battery. [Means for solving the problem]

[0004] In order to achieve the above object, the present invention provides a battery case comprising a cup-shaped bottom cap and a sealing cap for sealing an opening of the bottom cap, the bottom cap includes a circular or elliptical bottom wall and an annular side wall; The sealing cap includes, in order from the outside to the inside, an outer contact layer, an insulating layer, and an inner contact layer; a maximum outer diameter D1 of the outer contact layer is smaller than a maximum outer diameter D2 of the inner contact layer; the outer contact layer includes an electrode contact and a conductive junction; the insulating layer includes an insulating joint and an insulating opening; the inner contact layer includes welds, weld joints, and weld openings; a welding support is provided near the opening in the side wall; the electrode contact portion faces into the bottom cap through the insulating opening and the welding opening, and is electrically connected to one electrode of the battery cell to form electrical continuity between the outer contact layer and the battery cell; the conductive joint is seamlessly joined to the insulating joint, and is used to reinforce the strength of the sealing cap and prevent external water from entering the inside of the battery case; the welded portion is welded to the weld support portion to complete the sealing of the sealing cap and the bottom cap; the welded joint is seamlessly joined to the insulating joint, and is used to reinforce the strength of the sealing cap, reduce the direct contact area between the insulating joint and the inside of the battery case, and prevent external water from entering the inside of the battery case; Before sealing the sealing cap and the bottom cap, the insulating joint is seamlessly joined to the conductive joint and the welded joint by melting an insulating anti-electrolyte corrosion material with a thermal shrinkage rate of 6% or less at 100°C or higher, and the joint strength between the conductive joint and the welded joint at room temperature is 1.0 N / mm 2 As described above, the thickness d3 of the insulating joint is 0.01 mm to 2.5 mm, and the contact area S0 between the insulating joint and the inside of the battery case satisfies S0<=π*D2*d3*½.

[0005] Optionally, the material of the outer contact layer is stainless steel and the thickness d4 of the outer contact layer is 0.1 mm to 0.25 mm, and / or the material of the inner contact layer is stainless steel and the thickness d5 of the inner contact layer is 0.1 mm to 0.25 mm.

[0006] Optionally, the material of the insulating layer is one or more of PP, PFA, PVDF, PTFE, ETFE and PVC.

[0007] Optionally, the insulating joint has a bond strength between the conductive joint and the welded joint at room temperature of 5.0 N / mm or less.

[0008] Optionally, the area S1 of the insulating joint and the area S2 of the insulating layer satisfy S1 / S2>=0.6, and / or the area S1 of the insulating joint and the area S3 of the outer contact layer satisfy S1 / S3>=0.5.

[0009] Optionally, a first bond reinforcement layer is provided on a first surface layer of the conductive joint close to the insulating joint to reinforce the bond strength with the insulating joint, and / or a second bond reinforcement layer is provided on a second surface layer of the welded joint close to the insulating joint to reinforce the bond strength with the insulating joint.

[0010] Optionally, an extension is further provided on the side wall, the extension protruding outward from the weld support by a certain height h, the extension height h being equal to or greater than the sum of the thickness d3 of the insulating joint and the thickness d4 of the outer contact layer.

[0011] Optionally, the battery case further includes a protective member, which is formed by pouring a liquid adhesive into recesses formed in the extensions, the welds, the insulating joints, and the outer edge of the outer contact layer, and then curing the liquid adhesive at room temperature after the sealing cap and the bottom cap are sealed.

[0012] Optionally, an insulating unit is provided inside the welding opening, and the insulating unit is used to prevent one electrode of the battery cell from contacting the inner contact layer and forming a short circuit when electrically connected to the electrode contact portion.

[0013] The present invention provides a battery comprising a battery cell and the battery case described above, wherein one electrode of the battery cell is electrically connected to the outer contact layer of the battery case, and the other electrode is electrically connected to the inner contact layer and / or bottom cap of the battery case.

[0014] The present invention divides the battery case into a bottom cap and a sealing cap, and divides the sealing cap into an outer contact layer, an insulating layer and an inner contact layer. The electrode contact of the outer contact layer penetrates the insulating layer and the inner contact layer to electrically connect with one electrode of the battery cell, and the other electrode of the battery cell to electrically connect with the bottom cap. The inner contact layer and the bottom cap can be welded together to realize the packaging of the battery cell, and the inner contact layer and the outer contact layer are insulated by the insulating layer, and the bottom cap is also insulated from the outer contact layer, which can prevent short-circuiting between the two electrodes of the battery cell. Since the inner and outer contact layers are pre-insulated, no additional insulating film is required when assembling the sealing cap to the bottom cap; it is sufficient to simply weld the inner contact layer and the bottom cap together, which simplifies the battery packaging process and improves packaging efficiency. Furthermore, by limiting the contact area S0 between the insulating joint and the inside of the battery case to S0 <= π*D2*d3*1 / 2, the area of ​​the insulating joint exposed to the electrolyte can be reduced, which reduces corrosion of the insulating layer by the electrolyte and ensures the stability of the joint between the insulating layer and the outer and inner contact layers. [Brief explanation of the drawings]

[0015] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following will briefly describe the accompanying drawings that need to be used in the description of the embodiments or prior art. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without any creative work. [Figure 1] FIG. 2 is an exploded view of the structure of an embodiment of a battery case of the present invention. [Figure 2] FIG. 1 is an exploded cross-sectional view of an embodiment of a battery case of the present invention. [Figure 3] FIG. 1 is a cross-sectional view of an embodiment of a battery case according to the present invention. [Figure 4] 1 is a schematic cross-sectional view of an embodiment of a sealing cap of the present invention. [Figure 5] FIG. 4 is an exploded view of the structure of another embodiment of a battery case of the present invention.

[0016] The realization of the objects, functional characteristics and advantages of the present invention will be further explained in connection with examples and with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, but obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without any creative work are all included in the protection scope of the present invention.

[0018] It should be noted that, where directional indications (e.g., up, down, left, right, front, back, etc.) exist in accordance with an embodiment of the present invention, such directional indications are only used to describe the relative positions, movements, etc. between various components in a particular position (as shown in the accompanying drawings), and if the particular position is changed, the directional indications will also change accordingly.

[0019] Furthermore, when a description of an embodiment of the present invention is made using terms such as "first" or "second," such terms are used for explanatory purposes only and do not indicate or imply the relative importance or number of such technical features. Therefore, a feature defined as "first" or "second" expressly or imply the inclusion of at least one such feature. Furthermore, "and / or" as used herein means the inclusion of three parallel solutions, e.g., "A and / or B" includes solution A, solution B, or both A and B. Furthermore, technical solutions in each embodiment may be combined with each other, provided that such combinations are feasible by a person skilled in the art. If a combination of technical solutions contradicts or is not feasible, such a combination of technical solutions should be considered nonexistent and not within the scope of protection of the present invention.

[0020] The present invention provides a battery case for a button battery.

[0021] In an embodiment of the present invention, as shown in FIGS. 1 to 5 , the battery case includes a cup-shaped bottom cap 10 and a sealing cap 20 for sealing an opening of the bottom cap 10, the bottom cap 10 including a circular or elliptical bottom wall 11 and an annular side wall 12, the sealing cap 20 including, from outside to inside, an outer contact layer 21, an insulating layer 22, and an inner contact layer 23, the outer contact layer 21 having a maximum outer diameter D1 smaller than a maximum outer diameter D2 of the inner contact layer 23, the outer contact layer 21 including an electrode contact portion 211 and a conductive joint portion 212, the insulating layer 22 including an insulating joint portion 221 and an insulating opening portion 222, the inner contact layer 23 including a weld portion 231, a weld joint portion 232, and a weld opening portion 233, a weld support portion 121 provided near the opening of the side wall 12, and the electrode contact portion 211 extends through the insulating opening 222 and the welding opening 233 toward the inside of the bottom cap 10 and is electrically connected to one electrode of the battery cell 50 to establish electrical continuity between the outer contact layer 21 and the battery cell 50; the conductive joint 212 is seamlessly joined to the insulating joint 221 and is used to reinforce the strength of the sealing cap 20 and prevent external water from entering the inside of the battery case; the weld joint 231 is welded to the welding support 121 and seals the sealing cap 20 and the bottom cap 10; the weld joint 232 is seamlessly joined to the insulating joint 221 and is used to reinforce the strength of the sealing cap 20 and reduce the direct contact area between the insulating joint 221 and the inside of the battery case to prevent external water from entering the inside of the battery case;

[0022] Before sealing the sealing cap 20 and the bottom cap 10, the insulating joint 221 is seamlessly joined to the conductive joint 212 and the welded joint 232 by melting an insulating, anti-electrolyte corrosion material with a thermal shrinkage rate of 6% or less at 100°C or higher, and the bonding strength between the conductive joint 212 and the welded joint 232 at room temperature is 1.0 N / mm 2The thickness d3 of the insulating joint 221 is 0.01 mm to 2.5 mm, and the contact area S0 between the insulating joint 221 and the inside of the battery case satisfies S0<=π*D2*d3*1 / 2. Specifically, d3 may be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.5 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, or 2.5 mm. For small button batteries, the thickness d1 is preferably 0.15 mm to 0.25 mm. The specific thickness of the insulating joint can be specifically designed according to specific products. Preferably, the insulating joint and the insulating layer 22 are integrally molded.

[0023] Compared with the prior art, the battery case of the present application is sealed by welding, which greatly improves the sealing property and stability. The sealing is not achieved by pressing physical force between the cases, but by pre-forming the sealing cap 20 and insulating it with the insulating joint 221, which improves the insulation property and also provides protection under certain conditions. Furthermore, the sealing cap 20 of the battery case of the present application adopts a three-layer structure, which enhances its structural stability and robustness. The insulating joint is located between two layers of stainless steel, which provides excellent waterproofing and resistance to electrolyte corrosion. The contact area between the insulating joint and the outside of the battery case is very small, which effectively prevents external water from entering the battery case. At the same time, the insulating joint 221 has a relatively long path length between the outside of the battery case and the inside of the battery case, which further reduces the impact of external water and the like on the battery cells and electrolyte inside the battery case. Similarly, within the battery case, only the inner edge of the insulating joint 221 comes into contact with the electrolyte inside the battery case, which effectively reduces the contact area between the electrolyte and the insulating joint 221, effectively protecting the insulating joint 221 and preventing the insulating joint 221 from being softened or corroded by the electrolyte, which effectively improves the service life of the battery. Furthermore, the insulating joint 221 has a long path from the inside of the battery case to the outside of the battery case, which further improves the service life of the battery.

[0024] The bottom cap 10 is made of stainless steel plate, and the opening of the bottom cap 10 faces upward to accommodate the battery cell 50 and electrolyte. The bottom wall 11 and side wall 12 may be integrally injection molded or may be welded together, without any particular limitation. The outer contact layer 21 and inner contact layer 23 of the sealing cap 20 are made of stainless steel plate, and the outer contact layer 21 is connected to one electrode of the battery cell 50, and the inner contact layer 23 is connected to the bottom cap 10 and to the other electrode of the battery cell 50. The insulating layer 22 between the outer contact layer 21 and the inner contact layer 23 insulates the outer contact layer 21 from the inner contact layer 23, and the bottom cap 10 and the sealing cap 20 are insulated from each other, preventing mutual conduction between the two electrodes of the battery cell 50. This not only enables the sealing cap 20 and the bottom wall 11 of the bottom cap 10 to respectively form the two output electrodes of the battery, but also prevents short circuits due to mutual conduction between the two output electrodes. Compared with the prior art, current button battery cases use upper and lower cases together, with a plastic insulating ring in the middle, and the side walls of the battery case have a three-layer structure, while the side walls 12 of the battery case of the present application are only one layer. For the same case size, the battery case of the present application improves the internal usable space and contributes to improving the overall capacity of the battery.

[0025] The weld 231 is the position where the inner contact layer 23 is welded to the weld support 121, and is provided on the peripheral wall of the inner contact layer 23. The maximum outer diameter D1 of the outer contact layer 21 is smaller than the maximum outer diameter D2 of the inner contact layer 23. That is, the weld 231 protrudes radially from the peripheral wall of the outer contact layer 21, forming a gap between the peripheral wall of the outer contact layer 21 and the weld support 121, preventing contact between the outer contact layer 21 and the side wall 12. The weld opening 233 is an opening position of the inner contact layer 23, and the weld joint 232 is used for joining to the insulating layer 22. Here, the weld 231 is welded to the side wall 12, thereby achieving both the mutual fixation of the sealing cap 20 and the bottom cap 10 and the electrical conductivity between the inner contact layer 23 and the side wall 12. The insulating opening 222 of the insulating layer 22 corresponds to the welding opening 233 of the inner contact layer 23, the electrode contact portion 211 of the outer contact layer 21 faces the inside of the battery case through the insulating opening 222 and the welding opening 233, and the insulating opening 222 and the welding opening 233 are opened in the center of the sealing cap 20, ensuring that the electrode contact portion 211 is sufficiently spaced from each position on the side wall 12.

[0026] The electrodes of the battery cell 50 may extend through the insulating openings 222 and the welding openings 233 to contact the electrode contact portions 211, or the electrode contact portions 211 may protrude downward to contact the electrodes of the battery cell 50. Note that if the electrodes of the battery cell 50 extend upward to contact the electrode contact portions 211, the battery cell 50 must avoid the inner contact layer 23. The top and bottom surfaces of the insulating joints 221 are respectively connected to the conductive joints 212 and the welding joints 232, thereby realizing an insulating connection between the outer contact layer 21 and the inner contact layer 23. The inner contact layer 23 is welded to the side wall 12 for sealing, and the outer contact layer 21 and the inner contact layer 23 are seamlessly connected via the insulating layer 22, thereby realizing the closure of the sealing cap 20 to the bottom cap 10. Here, when the inner contact layer 23 is welded to the side wall 12, the inner contact layer 23 and the outer contact layer 21 are already insulated and connected, eliminating the need for a separate insulating film.

[0027] The insulating layer 22 is made of a material with insulating properties and resistance to electrolyte corrosion, and has a thermal shrinkage rate of 6% or less at temperatures above 100°C. Thermal shrinkage rate refers to the volume change due to the inherent thermal expansion rate of a thermoplastic material. That is, at temperatures above 100°C, the volume change of the insulating layer 22 is 6% or less of its original volume, so that the insulating layer 22 can be sufficiently melted and fully connected to the inner contact layer 23 and the outer contact layer 21, ensuring a good bonding effect. The bonding strength between the conductive joint 212 and the welded joint 232 of the insulating layer 22 at room temperature is 1.0 N / mm 2 Specifically, the insulating joint 221 has a bond strength of 5.0 N / mm or less between the conductive joint 212 and the welded joint 232 at room temperature, preventing excessive internal stress in the sealing cap 20 and subsequent damage to the sealing cap 20 due to internal forces during processing or use. The thickness d3 of the insulating joint 221 is set to 0.01 mm to 2.5 mm, allowing the insulating joint 221 to stably withstand temperature and external force changes, improving the bond stability of the insulating joint 221 while also allowing the overall thickness of the sealing cap 20 to be reasonably controlled.

[0028] The contact area S0 between the insulating joint 221 and the interior of the battery case satisfies S0 <= π*D2*d3*1 / 2. Note that the contact surface between the insulating joint 221 and the interior of the battery case refers to the area of ​​the insulating opening 222 exposed to the electrolyte, i.e., the opening wall area of ​​the insulating opening 222. The opening wall area S0 of the insulating opening 222 is preferably expressed as S0 = π*d3*the opening diameter of the insulating opening 222, i.e., the opening diameter of the insulating opening 222 is preferably equal to or less than D2*1 / 2. This effectively controls the area of ​​the insulating layer 22 exposed to the electrolyte, provided that the thickness d3 of the insulating layer 22 is sufficient, and reduces corrosion of the insulating layer 22 by the electrolyte or corrosion of the interface between the insulating layer 22 and the inner contact layer 23. This improves the structural stability and bonding strength of the insulating layer 22, prevents the insulating layer 22 from falling off the inner contact layer 23, and effectively improves the stability of the entire battery case.

[0029] In the present invention, the battery case is divided into a bottom cap 10 and a sealing cap 20, and the sealing cap 20 is divided into an outer contact layer 21, an insulating layer 22, and an inner contact layer 23. The electrode contact portion 211 of the outer contact layer 21 penetrates the insulating layer 22 and the inner contact layer 23 to electrically connect with one electrode of the battery cell 50, and the other electrode of the battery cell 50 electrically connects with the bottom cap 10. The inner contact layer 23 and the bottom cap 10 are welded together to realize the packaging of the battery cell 50. The inner contact layer 23 and the outer contact layer 21 are insulated by the insulating layer 22, so that the bottom cap 10 is also insulated from the outer contact layer 21, preventing short circuits caused by mutual conduction between the two electrodes of the battery cell 50. In addition, the inner contact layer 23 and the outer contact layer 21 of the sealing cap 20 are insulated in advance. Therefore, when assembling the sealing cap 20 to the bottom cap 10, it is only necessary to weld the inner contact layer 23 and the bottom cap 10 together, without the need to add an insulating film. This simplifies the battery packaging process and improves packaging efficiency. Furthermore, by limiting the contact area S0 between the insulating joint 221 and the inside of the battery case to S0 <= π*D2*d3*1 / 2, the area of ​​the insulating joint 221 exposed to the electrolyte is reduced, which reduces corrosion of the insulating layer 22 by the electrolyte and improves the bonding stability between the insulating layer 22 and the outer contact layer 21 and the inner contact layer 23.

[0030] Specifically, the outer contact layer 21 is made of stainless steel and has a thickness d4 of 0.1 mm to 0.25 mm, and / or the inner contact layer 23 is made of stainless steel and has a thickness d5 of 0.1 mm to 0.25 mm. Specifically, d4 and d5 may be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.5 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, or 2.5 mm. The stainless steel may be 304 stainless steel, which contains a high amount of nickel and exhibits an austenitic single-phase structure at room temperature, has high corrosion resistance, good cold forming and weldability, and high plasticity and toughness at low, room, and high temperatures. By using SUS304 for the outer contact layer 21 and the inner contact layer 23, the structural stability of the sealing cap 20 during processing and the chemical stability when used as a battery case can be ensured.

[0031] By setting the thickness d4 of the outer contact layer 21 and the thickness d5 of the inner contact layer 23 to 0.1 mm to 0.25 mm, it is possible to provide the outer contact layer 21 and the inner contact layer 23 with sufficient structural strength, and also to reasonably control the thickness dimension of the entire sealing cap 20. In practice, the material of the insulating layer 22 is one or more of PP (polypropylene), PFA (a copolymer of perfluoropropyl perfluorovinyl ether and a small amount of polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), ETFE (ethylene-tetrafluoroethylene copolymer), and PVC (polyvinyl chloride).

[0032] In one embodiment, the area S1 of the insulating joint 221 and the area S2 of the insulating layer 22 satisfy S1 / S2>=0.6, and / or the area S1 of the insulating joint 221 and the area S3 of the outer contact layer 21 satisfy S1 / S3>=0.5, thereby effectively ensuring the joint area between the insulating layer 22 and the outer contact layer 21 and improving the connection stability between the insulating layer 22 and the outer contact layer 21. At the same time, the size of the insulating opening 222 can be reasonably controlled, the area of ​​the electrode contact portion 211 can be effectively controlled, and the area utilization rate of the outer contact layer 21 can be improved.

[0033] In one embodiment, as shown in FIG. 3 , a first bond reinforcement layer 213 is provided on a first surface layer of the conductive joint 212 near the insulating joint 221 to reinforce the bond strength with the insulating joint 221, and / or a second bond reinforcement layer 234 is provided on a second surface layer of the welded joint 232 near the insulating joint 221 to reinforce the bond strength with the insulating joint 221. The specific form of the first bond reinforcement layer 213 is not particularly limited as long as it increases the contact area with the insulating joint 221 and strengthens the bond strength. For example, the first bond reinforcement layer 213 may be provided as a protrusion. The specific form and function of the second bond reinforcement layer 234 can be seen in the first bond reinforcement layer 213. Furthermore, to further improve the combined stability of the outer contact layer 21, the insulating layer 22, and the inner contact layer 23, the first bond reinforcement layer 213 and the second bond reinforcement layer 234 can be indirectly fitted together via the insulating layer 22.

[0034] Specifically, as shown in FIG. 4 , the first bond reinforcement layer 213 is a uniform first dull layer formed by sandblasting a first surface layer of the first stainless steel layer near the insulating bond 221, and / or the second bond reinforcement layer 234 is a uniform second dull layer formed by sandblasting a second surface layer of the second stainless steel layer near the insulating bond 221. In this embodiment, "uniform" does not mean absolutely uniform, but rather refers to the natural, uniform dullness formed by sandblasting the first surface layer. The first dull layer ensures a more uniform bond between each portion of the first surface layer and the insulating bond 221, thereby avoiding stress concentration. Similarly, the second dull layer ensures a more uniform bond between each portion of the second surface layer and the insulating bond 221. Forming the first bond reinforcement layer 213 and the second bond reinforcement layer 234 by sandblasting simplifies the processing method for the first bond reinforcement layer 213 and the second bond reinforcement layer 234, thereby improving processing efficiency.

[0035] In another embodiment, the first bonding reinforcement layer 213 is a first inclined sheet protruding from the first surface layer and forming a certain inclination angle with the first surface layer. The height of the first inclined sheet is smaller than the thickness of the insulating joint 221. The second bonding reinforcement layer 234 is a second inclined sheet protruding from the second surface layer and forming a certain inclination angle with the second surface layer. The height of the second inclined sheet is smaller than the thickness of the insulating joint 221. The first and second inclined sheets are alternately arranged with inclinations in opposite directions. A plurality of first inclined sheets are distributed on the first surface layer, and the molten bonding insulation layer 22 fills the space between adjacent first inclined sheets to bond and connect the sides of each first inclined sheet. The height of the first inclined sheet is the vertical distance between the end of the first inclined sheet and the first surface layer. The height of the first inclined sheet is smaller than the thickness of the insulating joint 221, preventing the first inclined sheet from contacting the second stainless steel layer after passing through the insulating joint 221. The distribution method and function of the second inclined sheet can be described with reference to the first inclined sheet. The first inclined sheet and the second inclined sheet are arranged alternately in the longitudinal direction, and the first inclined sheet and the second inclined sheet can be adjacent to each other after being inserted into the insulating joint 221, so that the outer contact layer 21 and the inner contact layer 23 can be brought closer to each other without reducing the thickness of the insulating joint 221, thereby improving the structural strength of the sealing cap 20.

[0036] In yet another embodiment, the first bond reinforcement layer 213 is a first recess recessed in the first surface layer, the first recess recessed in a direction away from the insulating bond layer, and / or the second bond reinforcement layer 234 is a second recess recessed in the second surface layer, the second recess recessed in a direction away from the insulating bond layer. The number of first recesses is multiple, and the multiple first recesses are distributed on the first surface layer. The molten insulating bond 221 fills the first recesses, increasing the connection area with the first surface layer and improving the bond strength between the outer contact layer 21 and the insulating bond 221. The arrangement direction and function of the second recesses can be described with reference to the first recesses and will not be repeated here.

[0037] 1 to 3, the side wall 12 further includes an extension 122, which protrudes outward from the weld support 121 by a certain height h, and the extension height h is equal to or greater than the sum of the thickness d3 of the insulating joint 221 and the thickness d4 of the outer contact layer 21. The extension 122 extends upward from the top of the weld support 121, and the top of the extension 122 protrudes from the top surface of the outer contact layer 21, so that the extension 122 can be connected to the protective cover of the outer contact layer 21 and effectively protect the sealing cap 20.

[0038] Specifically, as shown in FIGS. 1 to 3 , the battery case further includes a protective member 30. The protective member 30 is formed by pouring a liquid adhesive into the recesses formed in the extensions 122, the welds 231, the insulating joints 221, and the outer edge of the outer contact layer 21, and then curing the liquid adhesive at room temperature after the sealing cap 20 and the bottom cap 10 are sealed. The insulating joints 221 protrude from the top surface of a portion of the peripheral wall of the outer contact layer 21 to form a groove bottom of the recess. The peripheral wall of the outer contact layer 21 and the inner peripheral wall of the extensions 122 form the groove wall of the recess, which extends along the circumferential direction of the outer contact layer 21. The protective member 30 not only covers the top surface of the protruding portion of the insulating joint layer, but also effectively isolates the outer contact layer 21 from the extensions 122, preventing electrical conduction between the outer contact layer 21 and the inner contact layer 23 or the sidewall 12. It should be understood that by hardening the liquid adhesive to form the protective member 30, not only can the insulation between the outer contact layer 21 and the inner contact layer 23 or the extension 122 be achieved, but also the biasing force of the protective member 30 on the outer contact layer 21 or the extension 122 can be reduced, the deformation of the outer contact layer 21 or the extension 122 can be facilitated, and the structural stability of the battery case can be ensured.

[0039] 1 to 3 , an insulating unit 40 is provided inside the weld opening 233, and the insulating unit 40 is used to prevent one electrode of the battery cell 50 from contacting the inner contact layer 23 and forming a short circuit when electrically connected to the electrode contact portion 211. The insulating unit 40 is provided in an annular shape and can extend along the circumferential direction of the weld opening 233. The insulating unit 40 fits tightly against the opening wall of the weld opening 233 and covers the weld opening 233, preventing contact between the electrode connected to the electrode contact portion 211 and the inner contact layer 23, and further preventing a short circuit between the two electrodes of the battery cell 50.

[0040] 5 , the insulating layer 22 may include a first adhesive layer 223, a conductive prevention layer 224, and a second adhesive layer 225, which are stacked together. The first adhesive layer 223 bonds the outer contact layer 21 and the conductive prevention layer 224, and the second adhesive layer 225 bonds the inner contact layer 23 and the conductive prevention layer 224. The conductive prevention layer 224 ensures mutual insulation between the outer contact layer 21 and the inner contact layer 23. In this way, the first adhesive layer 223 and the second adhesive layer 225 only need to have adhesive properties, and the conductive prevention layer 224 only needs to have insulating properties. The two properties of the insulating layer 22 can be achieved through different functional layers, which can further enhance the adhesive properties and insulating properties of the corresponding layers and improve the overall performance of the insulating layer 22.

[0041] The present invention further provides a battery comprising a battery cell 50 and a battery case. The specific structure of the battery case can be referenced from the above-described embodiments. Since the present battery employs all the technical solutions of the above-described embodiments, it at least achieves all the beneficial effects provided by the technical solutions of the above-described embodiments, and these will not be repeated here. Here, one electrode of the battery cell 50 is electrically connected to the outer contact layer 21 of the battery case, and the other electrode is electrically connected to the inner contact layer 23 of the battery case and / or the bottom cap 10. The present battery may be provided as a button battery, which is primarily used in electronic products to supply electrical energy to the electronic products. The electronic products may be low-voltage electronic products such as headphones and watches.

[0042] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. Equivalent structural modifications made based on the contents of the specification and accompanying drawings of the present invention under the inventive concept of the present invention, or equivalent structural modifications made by directly or indirectly applying to other related technical fields, are all included in the patent protection scope of the present invention. [Explanation of symbols]

[0043] 10 Bottom Cap 20 Sealing Cap 11 Bottom wall 12 Side wall 21 Outer contact layer 22 Insulating layer 23 Inner contact layer 211 Electrode contact part 212 Conductive joint 221 Insulated joints 222 Insulated opening 231 Welded Parts 232 Welded joints 233 Welded Opening 121 Welding support 213 First joint reinforcement layer 234 Second joint reinforcement layer 122 Stretching section 30 Protective material 40 Isolation Unit 50 battery cells 223 1st bonding layer 224 Conduction prevention layer 225 Second bonding layer

Claims

1. A battery case for a button battery, the battery case includes a cup-shaped bottom cap and a sealing cap for sealing an opening of the bottom cap; the bottom cap includes a circular or elliptical bottom wall and an annular side wall; The sealing cap includes, in order from the outside to the inside, an outer contact layer, an insulating layer, and an inner contact layer; the maximum outer diameter D1 of the outer contact layer is smaller than the maximum outer diameter D2 of the inner contact layer; the outer contact layer includes an electrode contact and a conductive junction; the insulating layer includes an insulating joint and an insulating opening; the inner contact layer includes welds, weld joints, and weld openings; a welding support is provided near the opening in the side wall; an extension portion is further provided on the side wall, the extension portion protruding from the welding support portion and extending outward by a certain height h, the height h of the extension portion being equal to or greater than the sum of the thickness d3 of the insulating joint portion and the thickness d4 of the outer contact layer; the battery case further includes a protective member, and the protective member is formed by pouring a liquid adhesive into recesses formed on the extensions, the welds, the insulating joints, and the outer edge of the outer contact layer, and curing the liquid adhesive at room temperature after the sealing cap and the bottom cap are sealed; an insulating unit is provided inside the welding opening, and the insulating unit is used to prevent a short circuit from being formed by contacting the inner contact layer when one electrode of the battery cell is electrically connected to the electrode contact portion; the electrode contact portion faces into the bottom cap through the insulating opening and the welding opening, and is electrically connected to one electrode of the battery cell to form electrical continuity between the outer contact layer and the battery cell; the conductive joint is seamlessly joined to the insulating joint, and is used to reinforce the strength of the sealing cap and prevent external water from entering the inside of the battery case; the welded portion is welded to the weld support portion to complete the sealing of the sealing cap and the bottom cap; the welded joint is seamlessly joined to the insulating joint, and is used to reinforce the strength of the sealing cap, reduce the direct contact area between the insulating joint and the inside of the battery case, and prevent external water from entering the inside of the battery case; Before sealing the sealing cap and the bottom cap, the insulating joint is seamlessly joined to the conductive joint and the welded joint by melting an insulating anti-electrolyte corrosion material having a thermal shrinkage rate of 6% or less at 100°C or higher, and the joint strength between the conductive joint and the welded joint at room temperature is 1.0 N / mm ２ The above, wherein a thickness d3 of the insulating joint is 0.01 mm to 2.5 mm, and a contact area S0 between the insulating joint and the inside of the battery case satisfies S0 <= π * D2 * d3 * 1 / 2.

2. 2. The battery case of claim 1, wherein the outer contact layer is made of stainless steel and has a thickness d4 of 0.1 mm to 0.25 mm, and / or the inner contact layer is made of stainless steel and has a thickness d5 of 0.1 mm to 0.25 mm.

3. 2. The battery case according to claim 1, wherein the insulating layer is made of one or more of PP, PFA, PVDF, PTFE, ETFE, and PVC.

4. 2. The battery case according to claim 1, wherein the insulating joint has a bond strength between the conductive joint and the welded joint at room temperature of 5.0 N / mm or less.

5. 2. The battery case according to claim 1, wherein the area S1 of the insulating joint and the area S2 of the insulating layer satisfy S1 / S2 ≥ 0.6, and / or the area S1 of the insulating joint and the area S3 of the outer contact layer satisfy S1 / S3 ≥ 0.

5.

6. The battery case according to any one of claims 1 to 5, characterized in that a first bond reinforcement layer is provided on a first surface layer of the conductive joint portion near the insulating joint portion to reinforce the bond strength with the insulating joint portion, and / or a second bond reinforcement layer is provided on a second surface layer of the welded joint portion near the insulating joint portion to reinforce the bond strength with the insulating joint portion.

7. A battery comprising a battery cell and the battery case according to any one of claims 1 to 6, wherein one electrode of the battery cell is electrically connected to an outer contact layer of the battery case, and the other electrode is electrically connected to an inner contact layer and / or a bottom cap of the battery case.

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