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, the sealing cap is divided into an outer contact layer, an insulating layer and an inner contact layer, the electrode connection part of the inner contact layer is electrically conductive with one electrode of the battery cell, and the other electrode of the battery cell is electrically conductive with the bottom cap, the outer contact layer and the bottom cap can be welded to realize packaging of the battery cell, the inner contact layer and the outer contact layer are insulated by the insulating layer, and the bottom cap is also insulated from the inner contact layer, which can prevent short circuit between the two electrodes of the battery cell, and 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 outer 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 the positive electrode casing and the negative electrode casing. To prevent the button battery from short-circuiting, the positive electrode casing and the negative electrode casing must be insulated from each other. In related technologies, insulation is achieved by providing an insulating film between the positive electrode casing and the negative electrode casing, and the positive electrode casing and the negative electrode casing are welded together. However, during the processing process, it is difficult to install the insulating film, which makes processing the button battery more difficult and reduces 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, which solves the technical problem of how to improve the efficiency of battery processing. [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 greater than a maximum outer diameter D2 of the inner contact layer; the inner contact layer includes outer electrical connections, electrode connections, and conductive joints; the insulating layer includes an insulating joint and an insulating opening; the outer contact layer includes welds, weld joints, and weld openings; a welding support is provided near the opening in the side wall; the electrode connection portion is located on a surface of the inner contact layer facing the inside of the battery case, is electrically connected to one electrode of the battery cell, and is used to establish electrical conduction between the inner contact layer and the battery cell; the outer electrical connection is electrically connected to an external device through the insulating opening and the weld opening; the conductive 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; 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 used to increase the strength of the sealing cap 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 / S2>=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, the outer electrical connection is located at the bottom of the insulation opening and the weld opening.

[0011] Optionally, the outer electrical connection portion protrudes toward the outside of the battery case and passes through the insulating opening and the welding opening in that order, and the diameter D6 of the outer electrical connection portion is less than half the maximum outer diameter D2 of the inner contact layer.

[0012] Optionally, the battery case further includes a protective member, which is formed by hardening a gap-filling liquid adhesive provided between the outer electrical connection portion, the insulating opening, and the welding opening at room temperature after the sealing cap and the bottom cap are sealed.

[0013] The present invention further provides a battery comprising a battery cell and the above-described battery case, 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] In this invention, the battery case is divided into a bottom cap and a sealing cap. The sealing cap is divided into an outer contact layer, an insulating layer, and an inner contact layer. The electrode connection of the inner contact layer is electrically conductive with one electrode of the battery cell, and the other electrode of the battery cell is electrically conductive with the bottom cap. The outer contact layer and the bottom cap are welded together to achieve battery cell packaging. The inner and outer contact layers are insulated by the insulating layer, and the bottom cap is also insulated from the inner contact layer, preventing short circuits between the two electrodes of the battery cell. Because the inner and outer contact layers of the sealing cap are pre-insulated, no additional insulating film is required when assembling the sealing cap to the bottom cap; it only requires welding the outer contact layer to the bottom cap. This 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 contact area between the insulating joint and the inner and outer contact layers can be increased, ensuring joint stability. [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] 1 is a cross-sectional view of a battery case according to an embodiment of 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. [Figure 6] FIG. 4 is a cross-sectional exploded view of another embodiment of a battery case of the present invention. [Figure 7] FIG. 2 is a cross-sectional view of another embodiment of a battery case according to the present invention. [Figure 8] FIG. 10 is an exploded view of the structure of still 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 8 , a 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 includes a circular or elliptical bottom wall 11 and an annular side wall 12, the sealing cap 20 includes, from outside to inside, an outer contact layer 21, an insulating layer 22 and an inner contact layer 23, the outer contact layer 21 has a maximum outer diameter D1 greater than a maximum outer diameter D2 of the inner contact layer 23, the inner contact layer 23 includes an outer electrical connection portion 231, an electrode connection portion 232 and a conductive joint portion 233, the insulating layer 22 includes an insulating joint portion 221 and an insulating opening 222, the outer contact layer 21 includes a weld portion 211, a weld joint portion 212 and a weld opening 213, a weld support portion 121 is provided near the opening of the side wall 12, and the electrode connection portion 232 is connected to the inner contact layer 23 3, which is located on the inner surface of the battery case, is electrically connected to one electrode of the battery cell 40, and is used to establish electrical continuity between the inner contact layer 23 and the battery cell 40; the outer electrical connection portion 231 is electrically connected to an external device through the insulating opening 222 and the welding opening 213; the conductive joint 233 is seamlessly joined to the insulating joint 221, and is used to increase the strength of the sealing cap 20, reduce the direct contact area between the insulating joint 221 and the inside of the battery case, and prevent external water from entering the inside of the battery case; the weld portion 211 is welded to the welding support 121, and is used to seal the sealing cap 20 and the bottom cap 10; the weld joint 212 is used to increase the strength of the sealing cap 20 and prevent external water from entering the inside of the battery case; Before sealing the sealing cap 20 and the bottom cap 10, the insulating joint 221 is seamlessly joined to the conductive joint 233 and the welded joint 212 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 233 and the welded joint 212 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 interior 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 d3 is preferably 0.15 mm to 0.25 mm. The specific thickness of the insulating joint 221 can be specifically designed according to the specific product. Preferably, the insulating joint 221 and the insulating layer 22 are integrally molded.

[0022] 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. Because the insulating joint 221 is located between two layers of stainless steel, it has excellent waterproof and electrolyte-resistant properties. The contact area between the insulating joint 221 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 between the outside of the battery case and the inside of the battery case, which further reduces the impact of external water 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 electrolyte from softening or corroding the insulating joint 221. This effectively improves the service life of the battery. Furthermore, because the insulating joint 221 has a long path from the inside of the battery case to the outside of the battery case, the service life of the battery can be further improved.

[0023] 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 40 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 electrode connection portion 232 of the inner contact layer 23 faces inside the battery case and is connected to one electrode of the battery cell 40. The outer contact layer 21 is connected to the bottom cap 10 and is connected to the other electrode of the battery cell 40. The insulating layer 22 is provided between the outer contact layer 21 and the inner contact layer 23, insulating the outer contact layer 21 from the inner contact layer 23 and insulating the bottom cap 10 and the sealing cap 20 from each other, preventing mutual conduction between the two electrodes of the battery cell 40. 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. The outer electrical connection portion 231 faces the outside of the sealing cap 20 through the insulating opening 222 and the conductive opening and is electrically connected to an external device. The outer electrical connection portion 231 may be disposed at the bottom of the insulating opening 222 and the welding opening 213, or may protrude toward the outside of the battery case and pass through the insulating opening 222 and the welding opening 213 in order, but is not particularly limited thereto as long as the outer electrical connection portion 231 is exposed to the sealing cap 20.

[0024] 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 211 is a position where the inner contact layer 21 is welded to the weld support 121, and is provided on the peripheral wall of the inner contact layer 21. The maximum outer diameter D1 of the outer contact layer 21 is larger than the maximum outer diameter D2 of the inner contact layer 23. That is, the weld 211 protrudes radially from the peripheral wall of the inner contact layer 23, forming a gap between the peripheral wall of the inner contact layer 23 and the weld support 121 to prevent contact between the outer contact layer 21 and the side wall 12. The weld opening 213 is an opening position of the outer contact layer, and the weld joint 212 is used to join to the insulating layer 22. Here, the weld 211 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 outer contact layer 21 and the side wall 12. The insulating openings 222 in the insulating layer 22 correspond to the welding openings 213 in the outer contact layer 21, and the outer connection portions 231 of the inner contact layer 23 face the outside of the battery case through the insulating openings 222 and the welding openings 213. The insulating openings 222 and the welding openings 213 are opened in the center of the sealing cap 20, ensuring that the external electrical connection portions 231 are sufficiently spaced from each position on the side wall 12.

[0026] The electrodes of the battery cells 40 may be in direct contact with the electrode connection portions 232 of the inner contact layer 23. The top and bottom surfaces of the insulating joints 221 are bonded to the conductive joints 233 and the weld joints 212, respectively, to achieve an insulating connection between the outer contact layer 21 and the inner contact layer 23. The outer contact layer 21 is welded and sealed to the sidewall 12, and the inner contact layer 23 is seamlessly bonded to the outer contact layer 21 via the insulating layer 22, thereby realizing the closure of the sealing cap 20 and the bottom cap 10. Here, since the outer contact layer 21 and the inner contact layer 23 are already insulated and connected when the outer contact layer 21 and the sidewall 12 are welded together, there is no need to provide 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 233 of the insulating layer 22 and the welded joint 212 at room temperature is 1.0 N / mm 2 As described above, the bonding stability of the insulating layer 22 and the inner contact layer 23 and the outer contact layer 21 is ensured. Specifically, the bonding strength between the insulating joint 221, the conductive joint 233 and the welded joint 212 at room temperature is 5.0 N / mm 2 or less, which can prevent the internal stress of the sealing cap 20 from becoming too high and causing damage to the sealing cap 20 due to internal forces during subsequent processing or use. The thickness d3 of the insulating joint 221 is set to 0.01 mm to 2.5 mm, which allows the insulating joint 221 to stably withstand changes in temperature and external forces and improves the bonding 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 of the insulating joint 221 with the interior of the battery case satisfies S0 >= π*D2*d3*½, where the contact area between the insulating joint 221 and the interior of the battery case refers to the area of ​​the insulating joint 221 exposed to the electrolyte, i.e., the outer wall area of ​​the insulating layer 22. The outer wall area S0 of the insulating layer 22 = π*d3*maximum outer diameter of the insulating layer 22, i.e., the maximum outer diameter of the insulating layer 22 satisfies D2*½ or more. Therefore, by rationally controlling the thickness of the insulating layer 22, i.e., the contact area between the insulating joint 221 and the interior of the battery case, the connection area between the insulating joint 221 and the conductive joint 233 can be effectively increased, reducing the corrosion area of ​​the insulating layer 22 caused by the electrolyte and improving the bonding stability between the insulating layer 22 and the inner contact layer 23.

[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 connection portion 232 of the inner contact layer 23 is electrically conductive with one electrode of the battery cell 40, and the other electrode of the battery cell 40 is electrically conductive with the bottom cap 10. The outer contact layer 21 and the bottom cap 10 are welded together to realize the packaging of the battery cell 40. The inner contact layer 23 and the outer contact layer 21 are insulated by the insulating layer 22, so the bottom cap 10 is also insulated from the inner contact layer 23, preventing mutual conduction of the two electrodes of the battery cell 40. This prevents short circuits caused by the insulating layer 221 and the inner contact layer 23 of the sealing cap 20 from occurring, and since the inner contact layer 23 and the outer contact layer 21 of the sealing cap 20 are insulated in advance, when assembling the sealing cap 20 to the bottom cap 10, it is only necessary to weld the outer contact layer 21 and the bottom cap 10, without the need to add an insulating film, which 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 contact area between the insulating joint 221 and the inner contact layer 23 and the outer contact layer 21 can be increased, thereby improving joint stability.

[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 d6 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 / S2 >= 0.5, thereby effectively ensuring the joint area between the insulating layer 22 and the inner contact layer 23 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 outer electrical connection portion 231 can be effectively controlled, and the area utilization rate of the inner contact layer 23 can be improved.

[0033] In one embodiment, as shown in FIG. 3 , a first bond reinforcement layer 234 is provided on a first surface layer of the conductive joint 233 near the insulating joint 221 to enhance the bond strength with the insulating joint 221, and / or a second bond reinforcement layer 214 is provided on a second surface layer of the welded joint 212 near the insulating joint 221 to enhance the bond strength with the insulating joint 221. The specific form of the first bond reinforcement layer 234 is not particularly limited as long as it increases the connection area with the insulating joint 221 and enhances the bond strength. For example, the first bond reinforcement layer 234 may be provided as a protrusion. The specific form and function of the second bond reinforcement layer 214 can be referred to the first bond reinforcement layer 234. 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 234 and the second bond reinforcement layer 214 can be indirectly fitted together via the insulating layer 22.

[0034] Specifically, as shown in FIG. 4 , the first bond reinforcement layer 234 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 214 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 234 and the second bond reinforcement layer 214 by sandblasting simplifies the processing method for the first bond reinforcement layer 234 and the second bond reinforcement layer 214, improving processing efficiency.

[0035] In another embodiment, the first bonding reinforcement layer 234 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 214 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 inclined in opposite directions and alternately arranged. 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 234 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 214 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, and 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] In one embodiment, as shown in FIGS. 5 to 7 , the outer electrical connection portion 231 protrudes toward the outside of the battery case, passing through the insulating opening 222 and the weld opening 213 in that order. The diameter D6 of the outer electrical connection portion 231 is less than half the maximum outer diameter D2 of the inner contact layer 23. The outer electrical connection portion 231 protrudes toward the outside of the battery case, facilitating electrical connection between the outer electrical connection portion 231 and an external device and improving usability of the battery. The diameter D6 of the outer electrical connection portion 231 is less than half the maximum outer diameter D2 of the inner contact layer 23, providing a sufficient area for the conductive joint 233 to join with the insulating layer 22, thereby ensuring joint stability. Furthermore, there is a sufficient gap between the protruding outer electrical connection portion 231 and the weld opening 213 of the outer contact layer 21, preventing the outer electrical connection portion 231 from coming into contact with the weld joint 212 when the battery case is pressed.

[0038] 7 , the battery case further includes a protective member 30. The protective member 30 is formed by curing a gap-filling liquid adhesive between the outer electrical connection 231, the insulating opening 222, and the welding opening 213 at room temperature after the sealing cap 20 and the bottom cap 10 are sealed. The gaps between the outer electrical connection 231, the insulating opening 222, and the welding opening 213 extend along the circumferential direction of the outer electrical connection 231, and the protective member 30 is annularly attached to the gaps. The protective member 30 not only covers the exposed portion of the insulating joint 221 but also effectively isolates the outer electrical connection 231 from the welding joint 212, preventing electrical conduction between the outer contact layer 21 and the inner contact layer 23. Furthermore, since the protective member 30 is formed by hardening a liquid adhesive, it is not only possible to insulate the outer contact layer 21 and the inner contact layer 23, but also to ensure the biasing force of the protective member 30 on the outer contact layer 21 and the outer electrical connection portion 231, thereby avoiding deformation of the outer contact layer 21 and the outer electrical connection portion 231 and ensuring the structural stability of the battery case.

[0039] 8 , 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.

[0040] The present invention further provides a battery comprising a battery cell 40 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 40 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 include low-voltage electronic products such as headphones and watches.

[0041] 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]

[0042] 10 Bottom Cap 20 Sealing Cap 11 Bottom wall 12 Side wall 21 Outer contact layer 22 Insulating layer 23 Inner contact layer 231 External Electrical Connection 232 Electrode connection part 233 Conductive Joints 221 Insulated joints 222 Insulated opening 211 Welded parts 212 Welded joints 213 Welded Opening 121 Welding support 234 First joint reinforcement layer 214 Second joint reinforcement layer 30 Protective material 40 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 conductive bottom cap for accommodating a battery cell having a first electrode and a second electrode and an electrolyte, 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 is laminated, in this order from the outside to the inside, with a conductive outer contact layer having a first surface exposed to the outside of the battery case and a second surface on the reverse side of the first surface, an insulating layer having a first surface facing the second surface of the outer contact layer and a second surface on the reverse side of the first surface, and a conductive inner contact layer having a first surface facing the second surface of the insulating layer and a second surface on the reverse side of the first surface; the inner contact layer includes outer electrical connections, electrode connections, and conductive joints; the insulating layer includes an insulating joint provided adjacent to a peripheral wall of the insulating layer, and an insulating opening provided adjacent to the insulating joint in a center of the insulating layer, the outer contact layer includes welds, weld joints, and weld openings; a weld support is provided on a side wall of the bottom cap near the opening of the bottom cap; the weld portion of the outer contact layer protrudes from the peripheral wall of the inner contact layer along a radial direction, and a gap is formed between the peripheral wall of the inner contact layer and the weld support portion; the electrode connection portion is located on the second surface of the inner contact layer and is electrically connected to the first electrode of the battery cell that faces the electrode connection portion, and is used to establish electrical conduction between the inner contact layer and the battery cell; the outer electrical connection is electrically connected to an external device through the insulating opening and the weld opening; the conductive joint is seamlessly joined to the insulating joint so as to cover the entire second surface of the insulating layer at the insulating joint, thereby reinforcing the strength of the sealing cap, reducing the direct contact area between the insulating joint and the inside of the battery case, and preventing 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 used to increase the strength of the sealing cap 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 battery case is characterized in that 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. The insulating joint has a bond strength of 5.0 N / mm between the conductive joint and the welded joint at room temperature. ２ 2. The battery case according to claim 1, wherein:

5. 2. The battery case according to claim 1, wherein an area S1 of the insulating joint portion and an area S2 of the insulating layer satisfy the relationship S1 / S2>=0.

6.

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. 6. The battery case according to claim 1, wherein the external electrical connection portion is located at the bottom of the insulating opening and the welding opening.

8. The battery case according to any one of claims 1 to 5, characterized in that the outer electrical connection portion protrudes toward the outside of the battery case and passes through the insulating opening and the welding opening in that order, and a diameter D6 of the outer electrical connection portion is equal to or less than half of the maximum outer diameter D2 of the inner contact layer.

9. 10. The battery case according to claim 8, further comprising a protective member, wherein the protective member is formed by curing a gap-filling liquid adhesive provided between the outer electrical connection portion, the insulating opening, and the welding opening at room temperature after the sealing cap and the bottom cap are sealed.

10. A battery comprising the battery cell and a battery case described in any one of claims 1 to 9, wherein the second electrode of the battery cell is electrically connected to the outer contact layer and / or the bottom cap, which are welded to the welding support portion of the bottom cap at the welding portion.

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