Button battery

Abstract

Button battery (1), comprising: a positive cover assembly (220) comprising a positive cover (11) and a washer (20), the washer (20) being arranged inside the positive cover (11); a positive current collector (14) arranged inside the positive cover (11) and having a receiving space (144), wherein a through hole (142) is provided in the bottom wall of the positive current collector (14); a positive electrode foil (15) located in the receiving space (144); wherein the washer (20) comprises a washer part (21) and a spring element portion (22) which are arranged crosswise, the length of the washer part (21) is L1, the length of the spring element portion (22) is L2, L1>L2, wherein either one or both of the spring element portion (22) and the washer part (21) are provided with a raised structure (23), the raised structure (23) passes through the through hole (142) and is attached to the positive electrode foil (15).

Description

Technical field

[0001] This application relates to the field of battery technology, in particular to a button battery, a manufacturing method for a washer assembly and a button battery assembly method. background

[0002] As a power source, a stable power supply is a fundamental requirement for button batteries. Due to the high internal resistance of button batteries, this leads to a shortened battery life, a reduction in capacity, accelerated self-discharge, reduced voltage, and battery heating. Therefore, internal resistance is commonly used as an important indicator of the reliability and stability of button batteries. Specifically, the initial internal resistance of button batteries is required to be below 10 Ω and remain below 20 S2 after one week of storage at 85 °C.

[0003] With the evolution of society and market changes, the operating conditions for button batteries are becoming increasingly harsh. For example, button batteries are required to ensure stable power supply even under high temperatures, high humidity, high pressure, high-frequency vibration, and high centrifugal loads. This means that the internal resistance of the battery must remain below 15 Ω when stored for 100 hours at 125°C. Technical solution

[0004] With the increase of the storage temperature of the button battery from 85 °C to 125 °C, the structure of the positive current collector and the method of assembling the positive current collector with the positive cap provided in the relevant technology result in the positive cap becoming more bulged, the gap between the positive current collector and the positive cap becoming larger, which in turn leads to insufficient contact between the positive current collector and the positive cap and a decrease in the current collection efficiency of the positive current collector, and as a result, the battery can no longer ensure a stable power supply, thus no longer meeting the requirements of the current application scenarios for button batteries.

[0005] First aspect, the embodiments of the present application provide a button battery comprising: a positive lid assembly comprising a positive lid and a washer, the washer being disposed inside the positive lid; a positive current collector disposed inside the positive cover and provided with a receiving space, wherein a through hole is formed in the bottom wall of the positive current collector; a positive electrode foil located in the receiving chamber; wherein the washer comprises a washer part and a spring element portion which are arranged crosswise, the length of the washer part being L1 and the length of the spring element portion being L2, with L1 > L2, and wherein one or both of these portions are provided with a raised structure which passes through the through-hole and is fixed to the positive electrode foil.

[0006] Second aspect, the embodiments of the present application provide a manufacturing method for the washer configured as the above-mentioned button battery, the manufacturing method comprising: the use of a stamping process to produce several band-shaped, interconnected spring element combinations; the use of a stamping process to produce a plurality of band-shaped, interconnected sets of washers; After the spring element combination and the washer set have been aligned so that their centers coincide, they are welded together using laser welding equipment to form several interconnected washers.

[0007] Third aspect, the embodiments of the present application provide an assembly method for the above-mentioned button battery, the assembly method comprising: after adjusting the relative position degree between the washer assembly and the positive cover, the washer and the positive cover are welded together to form a positive cover assembly; inserting the positive electrode foil into the positive current collector to form a positive assembly; inserting the negative electrode foil into the negative cover to form a negative cover assembly; sequentially inserting the separator and the positive current collector assembly into the negative cover assembly to form a combination; filling the electrolyte into the combination; covering the end area of ​​the combination with the positive cover assembly. Beneficial effect

[0008] The present application provides a button battery in which, by adding a washer attached to the positive cap, the length of the washer portion is greater than the length of the spring element portion. This connects both ends of the washer portion to the positive current collector. One or both of the portions (the spring element portion and the washer portion) are also provided with a raised structure that serves to further fix the positive electrode foil. Thus, when the positive cap expands, the positive cap remains in contact with the positive electrode foil located inside the positive current collector, thereby improving the stability of the internal structure of the battery.

[0009] The manufacturing method for the washer provided by the present application involves first aligning a plurality of band-shaped interconnected spring element combinations and a plurality of band-shaped interconnected washer sets so that their centers coincide. Then, the spring element combination and the washer set are joined together by welding to form a plurality of interconnected washers. This can effectively increase the production efficiency of the washer and reduce the cost of the assembly process.

[0010] The button battery assembly method provided by the present application involves welding the washer to the positive cap. The raised structure provided on the washer serves to further fix the positive electrode foil. Thus, when the positive cap expands, the positive cap remains in contact with the positive electrode foil located inside the positive current collector, thereby improving the stability of the internal structure of the battery. Description of the drawings Fig. 1 is an angled sectional view of a button battery according to the embodiments of the present application; Fig. 2 is another angled sectional view of a button battery according to the embodiments of the present application; Fig. 3 is an angled sectional view of a button battery according to another embodiment of the present application; Fig. 4 is a perspective view of a washer according to the embodiments of the present application; Fig. 5a is an illustration of a washer assembly according to the embodiments of the present application; Fig. 5b is an illustration of a washer assembly according to another embodiment of the present application; Fig. 6 is an angled sectional view of a spring element according to the embodiments of the present application; Fig. 7a is an enlarged partial view of Fig. 6 according to the embodiments of the present application; Fig. 7b is another enlarged partial view of Fig. 6 according to the embodiments of the present application; Fig. 8 is another angled sectional view of a washer according to the embodiments of the present application; Fig. 9a is a perspective view of a washer according to a second embodiment of the present application; Fig. 9b is a perspective view of a washer according to a third embodiment of the present application; Fig. 9c is a perspective view of a washer according to a fourth embodiment of the present application; Fig. 9d is a perspective view of a washer according to a fifth embodiment of the present application; Fig. 10 is a perspective view of the washer and the positive cover after welding according to the embodiments of the present application; Fig. 11 is a sectional view of the washer and the positive cover after welding according to the embodiments of the present application; Fig. 12 is a front view of the washer and positive cap after welding according to the embodiments of the present application; Fig. 13 is a diagram showing the welding positions when welding the washer to the positive cover according to the embodiments of the present application; Fig. 14 is a positional schematic diagram of the washer and the positive current collector from a certain angle according to the embodiments of the present application; Fig. 15a is a schematic illustration of construction lines of the washer according to the embodiments of the present application; Fig. 15b is another schematic illustration of construction lines of the washer according to the embodiments of the present application; Fig. 16 is a schematic representation of the position of the washer and the positive current collector from a further angle, provided by embodiments of this application; Fig. 17 is a cross-sectional view of the washer and positive current collector provided by embodiments of this application; Fig. 18a is a schematic representation of the position of the washer and the positive current collector provided by a comparative example of this application; Fig. Figure 18b is another schematic representation of the position of the washer and the positive current collector provided by another comparative example of this application; Fig. 19 is a schematic representation of the dimensions of the washer provided by embodiments of this application; Fig. 20a is a sectional view of the washer provided by Embodiment 1 of this application; Fig. 20b is a sectional view of the washer provided by Comparative Example 1 of this application; Fig. 20c is a sectional view of the washer provided by Comparative Example 2 of this application; Fig. 21 is a sectional view of the button battery from a viewpoint provided by embodiments of this application; Fig. 22 is another cross-sectional view of the button battery from another angle provided by embodiments of this application; Fig. 23 is a sectional view of the button battery from a viewing angle provided by another embodiment of this application; Fig. 24 is a sectional view of the button battery from another angle provided by another embodiment of this application; Fig. 25 is a perspective view of the washer provided by embodiments of this application; Fig. 26a is a perspective view of the washer portion from one viewing angle provided by embodiments of this application; Fig. 26b is a perspective view of the washer portion from a further angle, provided by embodiments of this application; Fig. 26c is a perspective view of the washer portion from a different angle, provided by embodiments of this application; Fig. 27a is a perspective view of the spring element portion from one viewing angle, provided by embodiments of this application; Fig. 27b is a perspective view of the spring element portion from a further angle provided according to the embodiments of the present application; Fig. 27c is a cross-sectional view of the spring element portion from another angle provided according to the embodiments of the present application; Fig. 27d is a perspective view of the spring element portion provided according to another embodiment of the present application; Fig. 28 is a schematic illustration of the welding area between the spring element portion and the washer part provided according to the embodiments of the present application; Fig. Figure 29a is a partially enlarged view of a first structure of Fig. 27c; Fig. Figure 29b is a partially enlarged view of a second structure of Fig. 27c; Fig. Figure 29c is a partially enlarged view of a third structure of Fig. 27c; Fig. 30 is a partial cross-sectional view of the button battery provided according to the embodiments of the present application; Fig. 30a is a partial sectional view of the button battery provided according to a comparative example of the present application; Fig. 30b is a partial sectional view of the button battery provided according to another comparative example of the present application; Fig. 31 is a schematic representation of the washer-to-positive cap welding area provided in accordance with the present application; Fig. 32a is a perspective view of the washer provided according to another embodiment of the present application; Fig. 32b is a perspective view of the washer provided according to another embodiment of the present application; Fig. 33 is a sectional view after welding the washer to the positive cover provided according to the embodiments of the present application; Fig. 34 is a perspective view after welding the washer to the positive cover provided according to the embodiments of the present application; Fig. 35 is an illustration of the position requirements for the second washer-to-positive cap weld point provided in accordance with embodiments of the present application; Fig. 36a is a sectional view of the button battery with the positive lid bulged outward, from a viewing angle, provided according to the embodiments of the present application; Fig. 36b is a cross-sectional view of the button battery with the positive cover curved outward from a further angle, provided according to the embodiments of the present application; Fig. 37 is a schematic diagram 1 of the washer-positive current collector positional structure provided according to the embodiments of the present application; Fig. 38 is a schematic diagram 2 of the washer-positive current collector position structure provided according to the embodiments of the present application; Fig. 39 is a schematic diagram 3 of the positional structure between washer and positive current collector provided according to the embodiments of the present application; Fig. 40 is a schematic diagram of the washer-positive current collector positioning structure provided according to the embodiments of the present application; Fig. 41 is a schematic illustration of the construction line of the washer provided according to the embodiments of the present application; Fig. 42a is a schematic illustration 5 of the positional structure between washer and positive current collector provided according to the embodiments of the present application; Fig. 42b is a schematic diagram of the positional structure between the washer and the positive current collector provided according to a comparative example of the present application; Fig. 42c is a schematic diagram of the positional structure between the washer and the positive current collector provided according to another comparative example of the present application; Fig. 43a is a schematic representation of the raw material structure of the washer set provided according to the embodiments of the present application; Fig. 43b is a schematic representation of the raw material structure of the spring element combination provided according to the embodiments of the present application; Fig. 43c is a schematic representation of the raw material structure of the washer assembly provided according to the embodiments of the present application; Fig. 44a is a schematic diagram of the partial structure of the spring element portion provided according to Embodiment 1 of the present application; Fig. 44b is a schematic diagram of the partial structure of the spring element portion provided according to Comparative Example 1 of the present application; Fig. 44c is a schematic diagram of the partial structure of the spring element portion provided according to Comparative Example 2 of the present application. Reference symbols:

[0011] 1. Button battery; 11. Positive cap; 111. Raised structure; 12. Negative cap; 13. Sealing ring; 14. Positive current collector; 141. Annular bottom wall; 142. Through hole; 143. Side wall; 144. Receiving space; 15. Positive electrode foil; 16. Negative electrode foil; 17. Separator; 19. Electrolyte; 20. Washer; 21. Washer part; 211. Washer main body; 212. Washer ridge; 213. Washer receiving space; 214. Washer end portion; 2141. First washer end portion; 2142. Second washer end portion; 2143. Washer end point; 215. Washer side edge; 22. Spring element portion; 221. Spring element main body; 222. Spring element end section; 2221. First spring element end section; 2222. Second spring element end section; 2223. Spring element end point; 223. Spring element elevation; 224. Spring element receiving space; 23. Elevation structure; 231. First flange; 232. Second flange; 233. Elevation; 23a.protruding area; 23b. non-protruding area; 24. base area; 25. locating hole; 200. washer assembly; 210. first weld; 241. second weld; 242. third weld; 220. positive cover assembly; Q1. first area; Q2a. first sub-area; Q2b. second sub-area; Q3a. third sub-area; Q3b. fourth sub-area; Q4. fourth area; Q5. circular weld area; 100. positive assembly; 500. negative assembly; 300. spring element combination; 400. washer set. Examples of the applicationExemplary example 1

[0012] In this application, unless otherwise stated, the positional designations used, such as "top" and "bottom", generally refer to the top and bottom in the actual use or operating state of the device, specifically to the direction of the imaging plane in the accompanying drawings; whereas "inside" and "outside" are to be understood with reference to the contour of the device.

[0013] The button battery mainly consists of a positive cap, a negative cap, a sealing ring, a positive current collector, a positive electrode foil, a negative electrode active material, a separator and an electrolyte. In the relevant technology, in consideration of the cost of the battery assembly process, it is usually firstly to place the positive electrode foil inside the positive current collector, then the positive current collector is placed inside the positive cap, and then the positive cap and the positive current collector are tightly brought into contact with each other by sealing pressing.

[0014] Because the positive current collector is located directly inside the positive cap, and there is no positioning structure between the positive current collector and the positive cap, the positive current collector is prone to movement inside the button battery. Especially under strong vibration and high centrifugal force, the positive current collector will shift significantly, resulting in poor contact between internal components. Current fluctuations, low voltage, low capacity, and high internal resistance are easily experienced by the button battery. Furthermore, high-temperature storage causes the positive cap to expand, forming a gap between the positive cap and the positive current collector. This also causes poor contact between internal components, resulting in low voltage, poor discharge performance, and high internal resistance.

[0015] As an energy source, the button battery must ensure a stable power supply. Since a high internal resistance of the button battery shortens the battery life, reduces the capacity, increases the self-discharge rate, reduces the voltage, and promotes battery heating, the internal resistance is usually regarded as an important indicator of the reliability and stability of the button battery. Therefore, it is required that the initial internal resistance of the button battery is below 10Ω and remains below 20Ω after one week of storage at 85°C.

[0016] With the development of society and the changes in the market, the operating conditions for button batteries are becoming increasingly harsh. For example, button batteries are required to be able to supply power stably under high temperatures, high humidity, high pressure, high-frequency vibrations and high centrifugal force, i.e. after storage at 125°C for 100h, the internal resistance of the battery should be below 15Ω.

[0017] However, when the storage temperature of the button battery is increased from 85°C to 125°C, the structure of the positive current collector and its assembly method with the positive cap cause the degree of bulging of the positive cap to increase, the gap between the positive current collector and the positive cap to increase, and further lead to poor contacts between the positive current collector and the positive cap and a reduction in the current collection performance of the positive current collector, which in turn leads to a sharp increase in the internal resistance of the battery and cannot meet the requirements of the current application scenarios of the button battery.

[0018] In order to stabilize the electrical performance of the button battery under extreme environmental conditions, this application optimizes the internal structure of the button battery to improve the current collection performance.

[0019] With reference to Fig. 1 to Fig. 1 3, this application offers a button battery 1 comprising a positive cap 11, a negative cap 12, a sealing ring 13, a positive current collector 14, a positive electrode foil 15, a negative electrode foil 16, a separator 17 and electrolyte 19.

[0020] The positive cover 11 is configured as an open cap. As shown in Fig. 3, the outside of the positive cover 11 can be designed as a vertical surface, as in Fig. 1, the outer side of the positive cover 11 can also have a raised structure.

[0021] The negative cap 12 is also configured as an open cap, and both the inner diameter and the outer diameter of the positive cap 11 are larger than those of the negative cap 12, so that the positive cap 11 can cover the negative cap 12 externally.

[0022] The sealing ring 13 is attached to the junction between the positive lid 11 and the negative lid 12. The sealing ring 13 constructs at least a portion of the wall of the negative lid 12 as an enclosing structure, forming a sealed connection structure between the positive lid 11 and the negative lid 12. At the same time, the sealing ring 13 also serves to provide insulation between the positive lid 11 and the negative lid 12.

[0023] The positive current collector 14 is accommodated in the inner chamber of the positive cover 11. The positive current collector 14 can be designed as a current collector ring, current collector mesh, or current collector foil. As shown in Fig. 1, the positive current collector 14 is designed as a current collector ring. The positive current collector 14 comprises an annular bottom wall 141 and a side wall 143 attached circumferentially to the annular bottom wall 141. The annular bottom wall 141 and the side wall 143 together enclose a receiving space 144. A through hole 142 is formed in the annular bottom wall 141. The inner diameter of the positive current collector 14 is smaller than the inner diameter of the negative cover 12.

[0024] The positive electrode foil 15 is accommodated inside the receiving space 144 of the positive current collector 14 and is in contact with the positive cover 11 through the through hole 142.

[0025] The negative electrode foil 16 is accommodated in the inner chamber of the negative cover 12.

[0026] The separator 17 is arranged between the positive electrode foil 15 and the negative electrode foil 16 to separate them from each other. The projection of the negative electrode foil 16 onto the separator 17 can substantially coincide with the projection of the positive electrode foil 15 onto the separator 17.

[0027] The electrolyte 19 is filled throughout the interior of the button battery 1. After filling the electrolyte 19, the internal structures such as the negative electrode foil, the positive electrode foil, etc., are in an electrolyte-impregnated state, and the charged ions in the positive and negative electrode foils are electrically connected via the electrolyte.

[0028] With reference to the Fig. 1 to 3, the button battery 1 further includes a washer 20, wherein the washer 20 is attached to the inner surface of the positive cap 11. The washer 20 includes a washer part 21 and a spring element portion 22 arranged crosswise. The length L1 of the washer part 21 is greater than the length L2 of the spring element portion 22. The two ends of the washer part 21 are attached to the positive current collector 14. The spring element portion 22 is located inside the positive current collector 14. The spring element portion 22 and / or the washer part 21 are provided with a raised structure 23, wherein the raised structure 23 serves to fix the positive electrode foil 15.

[0029] By adding the washer 20 to the button battery 1, the washer 20 is connected to the positive cap 11, making the length of the washer portion 21 of the washer 20 longer than the length of the spring element portion 22. The two ends of the washer portion 21 are connected to the positive current collector 14, while the spring element portion 22 is located inside the positive current collector 14. One or both of the portions, namely the spring element portion 22 and the washer portion 21, are further provided with a raised structure 23, which serves to further fix the positive electrode foil 15. The washer 20 is configured to be separately connected to the positive cap 11 and the positive current collector 14, and the raised structure 23 on the washer 20 serves to further fix the positive electrode foil 15.As a result, when the positive cover 11 bulges, the positive electrode foil 15 inside the positive current collector 14 remains in contact with the positive cover 11, which increases the stability of the internal structure of the battery.

[0030] With reference to the Fig. 4 and Fig. 6, the washer part 21, the spring element section 22, and the raised structure 23 of the washer 20 are formed as a single piece. The thickness of the washer 20 is designated by t, where 0.05 mm ≤ t ≤ 0.30 mm.

[0031] The material used to manufacture the washer 20 can be one of SUS44, SUS304, SUS430, SUS316, or SUS444. In a specific embodiment, the washer 20 is made of SUS430, so that the washer 20 itself has magnetic properties. This helps facilitate the welding connection between the washer 20 and the positive cover 11 or the positive current collector 14, reducing the welding difficulty and increasing the welding feasibility.

[0032] The thickness of the washer is set in a range from 0.05 mm to 0.30 mm. In some embodiments, the thickness of the washer 20 is set in a range from 0.10 mm to 0.20 mm. In a specific implementation, the thickness of the washer 20 may be, for example, 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm, 0.25 mm, or 0.30 mm, or any value or range between any two of these values. Through research, the inventors have found that when the thickness t is < 0.05 mm, the washer 20 has insufficient strength and is easily deformed, thus preventing its elastic bonding effect from being sufficiently exerted. When the thickness t is > 0.30 mm, the volume of the washer 20 increases and takes up additional space inside the battery, resulting in a reduction in battery capacity.

[0033] As in Fig. 5a and Fig. 5b, the present application also provides a method of manufacturing a washer, wherein the washer is manufactured by a stamping and forming process, and during the stamping process, a plurality of washers 20 in the form of continuous edges of material are wound as strip material to form a plurality of washer assemblies 200 in roll form. With reference to Fig. 5a, a plurality of washers 20 are connected to one another via continuous material edges, wherein the individual washer 20 formed by cutting two adjacent washers 20 further has a protruding end structure on its side edge. Further referring to Fig. 5b, several washers 20 are directly connected to one another, and in the case of the single washer 20 formed by cutting two adjacent washers 20, the side edge is flush.

[0034] With reference to Fig. 4, the raised structure 23 arranged on the washer 20 for fixing the positive electrode foil 15 comprises a first flange 231 and a second flange 232, wherein the first flange 231 and the second flange 232 are each arranged at the two ends of the spring element section 22.

[0035] By providing a first flange 231 and a second flange 232 at each of the two ends of the spring element portion 22, the first flange 231 and the second flange 232 can engage with the positive electrode foil 15. Compared to arranging the raised structure 23 at other locations of the spring element portion 22, arranging the raised structure 23 at the two ends of the spring element portion 22 increases the contact area between the washer 20 and the positive electrode foil 15, thereby further improving the restraining effect of the raised structure 23 on the positive electrode foil 15.In particular, when the button battery 1 is in extreme vibration or centrifugal conditions, the first flange 231 and the second flange 232 can effectively reduce the positional changes of the positive current collector 14 and the washer 20 inside the battery, reduce the mutual impact forces between the positive electrode foil 15, the negative electrode foil 16 and the electrolyte 19, further reduce the internal resistance of the battery, and thus increase the stability of the battery performance.

[0036] As in Fig. 6, the height of the first flange 231 or the second flange 232 is h1, where 2·t≤h1≤10·t; the extension line angle from the outer sectional surface of the first flange 231 or the second flange 232 with the plane in which the spring element portion 22 is located is 90°~150°.

[0037] In some embodiments, the first flange 231 and the second flange 232 are arranged centrosymmetrically with respect to the washer 20. The height by which the first flange 231 rises relative to the base surface 24 of the spring element section 22 is the same as the height by which the second flange 232 rises relative to the base surface 24 of the spring element section 22 and is set to h1 in each case. In some embodiments, h1 can be a value of 2t, 3t, 4t, 5t, 6t, 7t, 8t, 9t, 10t, or any value between two of the above-mentioned values, or a range between two of the above-mentioned values.Through the inventor's research, it was found that when the height h1 of the first flange 231 or the second flange 232 satisfies the condition of 2 t ≤ h1 ≤ 10 t, after the first flange 231 and the second flange 232 are embedded in the positive electrode foil 15, the overall structure of the positive electrode foil 15 is not damaged by the first flange 231 or the second flange 232, so that neither damage (such as foil tearing) nor abrasion occurs, and no deformation occurs in the first flange 231 or the second flange 232 during embedding in the positive electrode foil 15. In particular, when the height h1 of the first flange 231 or the second flange 232 is less than 2t, the embedding depth in the positive electrode foil 15 is insufficient.When the positive cover 11 bulges outward, the first flange 231 or the second flange 232 easily detaches from the positive electrode foil 15, resulting in poor overall contact of the washer 20 with the positive current collector 14. If the height h1 of the first flange 231 or the second flange 232 is greater than 10t, deeper embedding into the positive electrode foil 15 is required. This makes the washer 20 more likely to deform during embedding, and the entire structure of the positive electrode foil 15 is also easily damaged.

[0038] With reference to Fig. 6, the extension line of the outer contour section of the first flange 231 or the second flange 232 forms an angle θ1 with the plane in which the spring element section 22 is located, which angle must satisfy the following condition: 90° ≤ θ1 ≤ 150°.

[0039] In the specific embodiment, the first flange 231 or the second flange 232 is arranged centrally symmetrically with respect to the washer 20. The extension path emanating from the outer surface of the first flange 231 and the extension path emanating from the outer surface of the second flange 232 each form the same angle, referred to as θ1, with the plane in which the spring element section 22 is located. θ1 must satisfy the following condition: 90° ≤ θ1 ≤ 150°. For example, θ1 can be 90°, 100°, 110°, 120°, 130°, 140°, 150°, or any angle or any range between these two angles. Through research, the inventor found that it is difficult to embed the first flange 231 or the second flange 232 into the positive electrode foil 15 when θ1 < 90°.When θ1 > 150°, the embedding area of ​​the first flange 231 or the second flange 232 in the positive electrode foil 15 is too large, which may easily damage the overall structure of the positive electrode foil 15 and cause particles to fall off.

[0040] The first flange 231 or the second flange 232 may be designed as a structure with a slanted, straight edge. As shown in Fig. 7a, the first flange 231 or the second flange 232 can also be designed as a wave-shaped inclined structure. As shown in Fig. 7b, the first flange 231 or the second flange 232 can also be designed as an inclined structure with an acute-angled end region.

[0041] With reference to Fig. 4 and Fig. 8, the raised structure 23 comprises at least two elevations 233 arranged on the washer part 21, wherein the at least two elevations 233 are each arranged symmetrically on both sides of the spring element section 22.

[0042] By providing at least two protrusions 233 on the washer part 21, these protrusions 233 can further engage the positive electrode foil 15, thereby increasing the contact area between the washer 20 and the positive electrode foil 15. This increases the restraining effect of the protrusion structure 23 on the positive electrode foil 15, so that the protrusion structure 23 can effectively prevent the relative displacement between the positive current collector 14 and the washer 20 within the button battery 1 during extreme vibrations or centrifugal forces of the button battery 1. This reduces the mutual impact forces between the positive electrode foil 15, the negative electrode foil 16, and the electrolyte, reduces the internal resistance of the button battery 1, and thus improves the stability of the electrical performance of the button battery 1.

[0043] Two projections 233 are provided on the washer portion 21 and are arranged symmetrically to the spring element portion 22. The first flange 231 and the second flange 232 are provided at both ends of the spring element portion 22, with the first flange 231 and the second flange 232 being arranged symmetrically to the washer portion 21. Since the washer portion 21 and the spring element portion 22 are arranged crosswise, the two projections 233 are designed to exert a fixing force on the positive electrode foil 15 in the first direction, while the first flange 231 and the second flange 232 are arranged to exert a fixing force on the positive electrode foil 15 in the second direction.The positive electrode foil 15 simultaneously experiences a fixing force in the first direction and a fixing force in the second direction, so that the washer 20 is able to completely limit the displacement of the positive electrode foil 15 relative to the washer 20 in extreme environments.

[0044] As in Fig. 8, the height of the elevation 233 is set to h2, where: 1.5 · t ≤ h2 ≤ 3 · t.

[0045] In the specific embodiment, the height h2 by which the elevation 233 rises relative to the plane of the washer part 21 can be set to 1.5t, 2.0t, 2.5t, 3.0t, as well as to any value between two of the aforementioned values, or to any range between two of the aforementioned values. Through investigations, the inventors have determined that if the height h2 of the two elevations 233 is < 1.5t, due to the insufficient embedding depth of the two elevations 233 in the positive electrode foil 15, the two elevations 233 can easily be separated from the positive electrode foil 15 when the positive cover 11 is curved outward. This leads to inadequate contact between the entire washer 20 and the positive current collector 14.On the other hand, if the height h2 of the two protrusions 233 is > 3 t, the two protrusions 233 have to embed themselves very deeply into the positive electrode foil 15, which makes the embedding process difficult and also leads to the overall structure of the positive electrode foil 15 being easily damaged, resulting in powder detachment.

[0046] The overall shape of the two elevations 233 can be a three-sided pyramid shape or a polygonal prism with pointed corners.

[0047] With reference to Fig. 4, Fig. 9a to Fig. 9d, the orthogonal projection of the washer 20 onto the positive cover 11 can be “+”-shaped, “ ”-shaped or as a combination of circular and “+”-shaped.

[0048] The base surface 24 of the washer 20 can be cross-shaped, with the washer part 21 and the spring element section 22 intersecting to form an intersection point. The washer part 21 comprises a first and a second section arranged symmetrically with respect to the intersection point. The spring element section 22 comprises a first and a second section, which are also arranged symmetrically with respect to the intersection point.

[0049] In some embodiments, as in Fig. 4, the base surface 24 of the washer 20 is formed as a regular "+"-shaped structure, wherein the two sections of the washer part 21 and the two sections of the spring element section 22 are each formed in a regular rectangular structure. In other optional embodiments, the base surface 24 of the washer 20 can be formed as an irregular "+"-shaped structure. As shown in Fig. 9a, the base surface 24 of the washer 20 is formed as an irregular "+"-shaped structure, with the two side edges of the two sections of the washer part 21 being designed as arcuate edges. Or as in Fig. As shown in Figure 9b, the base surface 24 of the washer 20 is formed as an irregular "+"-shaped structure, wherein the two sections of the washer part 21 are each designed in a sector-shaped structure, and the two sections of the spring element section 22 are also designed in a sector-shaped structure. Or as in Fig. As shown in Figure 9c, the base surface 24 of the washer 20 comprises an outer ring portion and an inner connecting portion, wherein the outer ring portion is designed as a closed, circular ring-shaped structure and the inner connecting portion is designed in a "+"-shaped structure, wherein the two ends of the washer part 21 are connected to the annular edge. With reference to Fig. 9d, the base surface 24 of the washer 20 is formed as a "G"-shaped structure or another polygonal structure. Several extension sections are provided on the outside of the intersection point, i.e., a third extension section, a fourth extension section, or a fifth extension section is arranged between the washer part 21 and the spring element section 22, wherein the length of the washer part 21 is greater than the length of the spring element section 22 as well as the length of the third extension section and the fourth extension section.

[0050] With reference to the Fig. 10 to Fig. 12, the washer 20 is provided with a positioning hole 25, which serves to position the washer 20 during welding to the positive cover 11. The washer 20 is welded to the inner surface of the positive cover 11 such that the concentricity between the washer 20 and the positive cover 11 is less than or equal to 0.3 mm.

[0051] The washer 20 is welded to the inner surface of the positive cover 11. A positioning hole 25 is provided in the center of the washer 20. The intersection area between the washer part 21 and the spring element section 22 is located in the center of the washer 20, and the positioning hole 25 is located in the center of this intersection area between the washer part 21 and the spring element section 22.

[0052] As in Fig. 5a and Fig. As shown in Figure 5b, the washer assembly 200, which is in roll form, is transferred to the laser welding system and separated into individual washers 20, while the positive cover 11 is fed by means of a vibrating bowl and positioned in a fixture. During the welding process between the washer 20 and the positive cover 11, the washer 20 is gripped by the fixture via the positioning hole 25 and centered on the inner surface of the positive cover 11 through said positioning hole 25. The washer 20 and the positive cover 11 are then joined together by laser welding.

[0053] During the assembly process, it is necessary to control the concentricity between the washer 20 and the positive cap 11 to ≤0.3 mm; in some embodiments, the concentricity between the washer 20 and the positive cap 11 is ≤0.1 mm. Through research, the inventor found that when the concentricity between the positive cap 11 and the washer 20 is >0.3 mm, a large misalignment occurs between the washer 20 and the positive cap 11, which in turn leads to a large misalignment between the washer 20 and the positive current collector 14. This reduces the current collection efficiency of the positive current collector 14 and ultimately degrades the electrical characteristics of the button battery 1.

[0054] As in Fig. As shown in Fig. 13, at least two first welding points 210 are formed by welding between the washer 20 and the positive cover 11, which are arranged symmetrically with respect to the center of the washer 20.

[0055] Through research, the inventor found that, during welding between the washer 20 and the positive cover 11, the number of first welds 210 formed by welding between the washer 20 and the positive cover 11 is set to two. Two first welds 210 contribute to increasing the welding strength between the washer 20 and the positive cover 11. If the number of first welds 210 formed by welding between the washer 20 and the positive cover 11 is only one, this will result in the washer 20 being slightly offset from the positive cover 11 and bulging at the edges. Conversely, if the number of first welds 210 is greater than two, the welding process between the washer 20 and the positive cover 11 becomes more complicated, and the welding cost increases.

[0056] How to continue in Fig. 13, the stability of the button battery 1 can be further improved by optimizing the position of the welding area between the washer 20 and the positive cover 11.

[0057] The base surface 24 of the washer 20 used for welding is divided into five regions, namely the first region Q1, the first sub-region Q2a, the second sub-region Q2b, the third sub-region Q3a, and the fourth sub-region Q3b. The first region Q1 is located at the intersection of the washer part 21 and the spring element portion 22. The first sub-region Q2a and the second sub-region Q2b are arranged on the two sides of the first region Q1 and are located on the washer part 21. The third sub-region Q3a and the fourth sub-region Q3b are arranged on the two sides of the first region Q1 and are located on the spring element portion 22. The length of the washer part 21 is L1, and the length d1 of the first region Q1 in the longitudinal direction of the washer part 21 satisfies the condition: d1 = 0.5L1.The width of the first region Q1 along the spring element section 22 corresponds to the width of the washer part 21.

[0058] The position of the first weld 210 between the washer 20 and the positive cover 11 can be arranged in the first region Q1 or on the first and second subregions Q2a and Q2b. In some specific embodiments, the position of the first weld 210 between the washer 20 and the positive cover 11 is arranged on the first and second subregions Q2a and Q2b and is located outside the third and fourth subregions Q3a and Q3b. The inventors have found through research that when the position of the first weld 210 is between the washer 20 and the positive cover 11 on the third subregions Q3a and Q3b, this causes the washer 20 to lose its elasticity in the regions of the third subregion Q3a and the fourth subregion Q3b.When the positive cover 11 bulges, since the areas where the first flange 231 and the second flange 232 of the washer 20 are located are welded to the positive cover 11, the first flange 231 and the second flange 232 are separated from the positive electrode foil 15. This further results in the washer 20 no longer being in good contact with the positive electrode foil 15, thereby invalidating the limiting function of the first flange 231 and the second flange 232 with respect to the positive electrode foil 15.

[0059] The present application further provides an assembly method for a button battery, comprising the following steps:

[0060] Welding the positive cover 11 to the washer 20 to form the positive cover assembly 220;

[0061] Pressing the positive electrode foil 15 into the interior of the positive current collector 14, thereby forming an annular positive electrode;

[0062] The negative electrode is placed inside the negative cap 12, and the separator 17 and the annular positive electrode are inserted sequentially. The negative cap 12 is wrapped with a sealing ring 13 on its outer surface. After filling with electrolyte, the above-mentioned positive cap assembly 220 is attached, and the button battery 1 is formed by sealing. After assembly, the button battery 1 is subjected to an aging process by pre-discharging.

[0063] The washer 20 is welded to the inner surface of the positive cover 11. The positive current collector 14 is positioned on the washer 20, whereby the positive current collector 14 and the washer 20 are not completely concentric with each other, i.e., there is a positional deviation between the center of the positive current collector 14 and the center of the washer 20.

[0064] As in Fig. As shown in Figures 14 to 17, the positive current collector 14 includes an annular bottom wall 141 on which a through hole 142 is formed. Both ends of the washer portion 21 are connected to the annular bottom wall 141.

[0065] As in Fig. 15a, Fig. 15b, Fig. 16 and Fig. As shown in Figure 17, the diameter of the circumferential circle corresponding to the edge of the washer part 21 is set as D1, the diameter of the circumferential circle corresponding to the edge of the spring element part 22 is set as D2, the diameter of the through hole 142 of the positive current collector 14 is set as D3, and the diameter of the annular bottom wall 141 of the positive current collector 14 is set as D4. The thickness of the positive current collector 14 is set as t1. The washer part 21 includes two end portions, and the side edge of one end portion has two end points. The angle between the connecting lines of the two end points and the center of the washer 20 is set as 2θ2.

[0066] As in Fig. 15a, in one embodiment, the washer part 21 comprises two washer side edges 215, with a protruding washer end portion 214 formed on each washer side edge 215. The side edge at which the washer end portion 214 is located comprises two washer end points 2143. The angle between the connecting lines of the two washer end points 2143 and the center of the washer 20 is defined as 2θ2.

[0067] With reference to Fig. 15b, in a further embodiment, the washer part 21 comprises two washer side edges 215 formed as straight edges. The washer end portion 214 is formed by the washer side edges 215. The washer end portion 214 comprises two washer end points. The angle between the connecting line of the two washer end points and the center of the washer 20 is defined as 2θ2.

[0068] In order to ensure that the two ends of the washer part 21 of the washer 20 always remain in contact with the annular bottom wall 141 of the positive current collector 14, that is, that the two ends of the washer part 21 are always located in the area Q3 of the annular bottom wall 141 of the positive current collector 14 and the two ends of the washer part 21 continue to overlap in the area Q3 of the annular bottom wall 141 of the positive current collector 14 even after the battery is closed, the inventor has found through research that the length L1 of the washer part 21 satisfies the following condition: L1 = D1 cosθ2, 1.02 D3 ≤ L1 / cosθ2 ≤ 0.98 (D4 - 2t1), that is, 1.02 D3 cosθ2 < L1 ≤ 0.98 · (D4 - 2t1) · cosθ2.

[0069] With reference to Fig. 18a, when the length of the washer part 21 is set as L1a, where L1a > 0.98 · (D4 - 2t1) · cosθ2, at least a portion of the area in which one of the flanges of the washer 20 is located projects beyond the edge of the positive current collector 14, such as the one shown in Fig. 18a. The area in which the other flange of the washer 20 is located does not project beyond the edge of the positive current collector 14, as shown in Fig. 18a. During sealing of the button battery 1, the strength of the edge of the positive current collector 14 is greater than the strength of the plane in which the bottom wall of the positive current collector 14 is located. The height of the protruding portion 23a of the washer 20 that protrudes beyond the edge of the positive current collector 14 is greater than the height of the non-protruding portion 23b of the washer 20 that does not protrude beyond the edge of the positive current collector 14. This results in a height difference inside the positive current collector 14, thereby deteriorating the current collecting effect of the positive current collector 14.

[0070] With reference to Fig. 18b, when the length of the washer part 21 is set as L1b, where L1b < 1.02 · D3 · cosθ2, the area where one of the flanges of the washer 20 is located is in the area of ​​the through hole 142 of the positive current collector 14, as shown in Fig. 18b shown projecting area 23a. The other flange of the washer 20 is located in the area of ​​the plane in which the bottom wall of the positive current collector 14 is located, as shown in Fig. 18b shown non-protruding area 23b. During the closing of the button battery 1, one of the edges of the washer 20 is in the area of ​​the through-hole 142 of the positive current collector 14, which in Fig. 18b as a protruding portion 23a, and the height of the protruding portion 23a is greater than the height of the portion where the other flange of the washer 20 is located in the plane of the bottom wall of the positive current collector 14, which is shown as a non-protruding portion 23b. This results in a height difference inside the positive current collector 14, thereby deteriorating the current collecting efficiency of the positive current collector 14.

[0071] With reference to Fig. 15a, Fig. 15b, Fig. 17 and Fig. 19, the length of the washer part 21 is defined as L1 and the length of the spring element portion 22 is defined as L2. The width by which the washer part 21 extends in the extension direction of the spring element portion 22 is denoted as w3. The spring element portion 22 includes two spring element end portions 222, each spring element end portion 222 including two spring element end points 2223. The angle between the connecting line of the two spring element end points 2223 and the center of the washer 20 is defined as 2·θ3. The diameter of the through hole 142 of the positive current collector 14 is defined as D3.

[0072] The first flange 231 and the second flange 232 of the washer 20 are formed as inclined structures with a certain inclination angle. When the button battery 1 is sealed, the first flange 231 and the second flange 232 are embedded in the positive electrode foil 15, thereby positioning the positive electrode foil 15. To ensure that the first flange 231 and the second flange 232 remain embedded in the positive electrode foil 15 and maintain elastic connection with the positive electrode foil 15 even when there is a positional misalignment between the washer 20 and the positive current collector 14 or an outward bulging of the positive cap 11, the inventor has found that the length L2 of the spring element portion 22 is set to satisfy the following condition: 1.5w3 ≤ L2 ≤ 0.98 D3 cosθ3.

[0073] When the length L2 of the spring element portion 22 exceeds 0.98·D3·cosθ3, the relative positional offset between the washer 20 and the positive current collector 14 is large, so that the first flange 231 and / or the second flange 232 cannot be embedded in the positive electrode foil 15. When the length L2 of the spring element portion 22 is less than 1.5·w3, the first flange 231 and the second flange 232 move outward with the outward bulge of the positive cover 11. This causes the first flange 231 and / or the second flange 232 to detach from the positive electrode foil 15. As a result, the washer 20 loses its elastic positioning function with respect to the positive current collector 14, resulting in poor contact between the washer 20 and the positive current collector 14.

[0074] The present application further provides a specific embodiment 1, as well as comparative example 1 and comparative example 2. Through high-temperature storage tests on the button batteries 1 provided in embodiment 1, comparative example 1, and comparative example 2, the change in the internal resistance of the battery under high-temperature conditions is further validated. Example 1

[0075] The button battery 1 provided in Embodiment 1 comprises a washer 20 whose cross-sectional structure in Fig. 20a. The base surface 24 of the washer 20 has a central, cross-shaped, rotationally symmetrical structure. The length ratios and parameters are as follows: L1 = 0.91 · (D4 - 2t1) · cosθ2, L2 = 0.72 · D3 · cosθ3, t = 0.10, θ1 = 120°, H1 = 4 · t. Comparison example 1

[0076] The button battery provided in Comparative Example 1 comprises a washer 20 whose cross-sectional structure in Fig. 20b. The base surface 24 of the washer 20 has a central, cross-shaped, rotationally symmetrical structure. The length ratios and parameters are as follows: L1 = 0.91 · (D4 - 2t1) · cosθ2, L2 = 0.72 · D3 · cosθ3, t = 0.10, θ1 = 120°, H1 = 10 · t. Comparison example 2

[0077] The button battery provided in Comparative Example 2 comprises a washer 20 whose cross-sectional structure in Fig. 20c. The base surface 24 of the washer 20 has a central, cross-shaped, rotationally symmetrical structure. The length ratios and parameters are as follows: L1 = 0.91 · (D4 - 2t1) · cosθ2, L2 = 0.72 · D3 · cosθ3, t = 0.10, θ3 = 120°, H1 = 2 · t.

[0078] (High-temperature storage test: evaluation of internal resistance) A high-temperature storage test is carried out as follows on the button batteries obtained in the above order from Working Example 1, Comparative Example 1 and Comparative Example 2 to evaluate the change in internal resistance at high temperature.

[0079] Specifically, first, the internal resistance (Ω) between the positive and negative electrodes of the button batteries of Working Example 1, Comparative Example 1, and Comparative Example 2 was measured in the same manner. The initial resistance (Ω) thus obtained was shown in Table 1 below. Then, the button batteries of Working Example 1, Comparative Example 1, and Comparative Example 2 were stored in a high-temperature furnace for one week. The internal temperature of the high-temperature furnace was set to 125°C. After one week of storage, the internal resistance (Ω) between the positive and negative electrodes of the button batteries of Working Example 1, Comparative Example 1, and Comparative Example 2 was measured again in the same manner. The measured internal resistance (Ω) was shown in Table 1 below. Table 1 Projekt Flanshhöhe Innenwiderstand(Ω) Innenwiderstandsanstiegsrate Anfänglich Nach einer Woche Lagerung Ausführungsbeispie l1 4t 3.461 6.671 93% Vergleichsbeispiel 1 10t 13.370 22.934 72% Vergleichsbeispiel 2 2t 3.451 14.423 318% Evaluation result:

[0080] As shown in Table 1, the button battery of Example 1 (flange height of 4 Ω) with an initial internal resistance of 3.461 Ω exhibits a significantly lower initial internal resistance than that of Comparison Group 1 (flange height of 10 Ω). After disassembling the battery, it was found that the initial internal resistance of Comparison Group 1 is significantly higher than that of Example 1. This is because the flange of the washer 20 is deformed after engaging the positive electrode foil 15, causing powder to fall off the positive electrode foil 15. This leads to poor internal contact, which in turn causes the significantly higher initial internal resistance of Comparison Group 1.

[0081] Comparing Example 1 (flange height of 4t) with Comparison Group 2 (flange height of 2t), there is no significant difference in the initial internal resistance of the button batteries. However, when the button batteries are stored at 125°C for one week, the increase rate of the internal resistance of the button batteries of Comparison Group 2 is significantly higher than that of the button batteries of Example 1. After CT image analysis of the button battery, it was found that the flange portion of the washer 20 and the positive electrode foil 15 of the button battery provided in Comparison Group 2 are separated, resulting in poor internal contact of the battery during high-temperature storage. Example 2

[0082] In related technology, the button battery mainly consists of a positive cap, a negative cap, a sealing ring, a positive electrode foil, a negative electrode foil, a positive current collector, a separator, and an electrolyte. Considering the manufacturing process and assembly cost, the positive current collector is usually formed into a plate-shaped, mesh-shaped, or ring-shaped structure. During the cell assembly process, the positive electrode foil and the positive current collector are combined to form a positive assembly, which is then inserted into the cell interior and sealed within the cell using a mold.

[0083] Since the positive assembly is fixed inside the cell solely by the mold pressure, this one-sided fastening method results in low reliability of the positive assembly's fixation inside the cell. Particularly under high centrifugal forces and high temperatures, the positive assembly can fluctuate and shift significantly within the cell. This significantly exacerbates the problem of separation between the positive assembly and the positive cap. Furthermore, there is an increased risk of contact between the positive electrode foil and the electrolyte, which significantly impairs battery performance stability and may result in the battery failing to meet the requirements of demanding operating environments.

[0084] For example, when the battery is operated at a high temperature of 150°C, the internal pressure of the battery increases due to gas formation in the electrolyte. This causes the positive cap and negative cap to deform and warp, forming a gap between the positive cap and the positive electrode foil. This increases the internal resistance of the battery, resulting in insufficient battery performance. When the battery is subjected to a centrifugal force of 3300g, the positive assembly is easily displaced due to the direct placement of the positive assembly inside the positive cap. Since there is no fixing or positioning measures between the bus ring / positive current collector / bus plate and the positive cap, the positive assembly is prone to movement inside the cell.This leads to mutual impact between the positive assembly and the electrolyte, which affects the stability of the electrical performance of the button battery and, in the worst case, may lead to failure of the button battery.

[0085] As a power source, the button battery must provide stable power over a temperature range of -40°C to 85°C. Since high internal resistance can lead to a shortened battery life, reduced battery capacity, accelerated self-discharge, voltage drop, and self-generated heat, internal resistance is one of the most important indicators for evaluating the reliability and stability of a button battery. Typically, the initial resistance of a button battery must be below 10 Ω, and the resistance must remain below 20 Ω after one week of storage at 85°C.

[0086] With the development of society and market changes, the operating environments of button batteries are becoming increasingly harsh. For example, button batteries are required to maintain a stable power supply under conditions such as high temperature, high humidity, high pressure, high-frequency vibration, and under the action of high-speed centrifugal force. Tests have shown that when the operating temperature rises from 85°C to 125°C, the structure of button batteries in the relevant technology has problems. In particular, the positive cap bulges outwards significantly due to the increased temperature, causing the gap between the positive cap and the positive current collector to widen. This leads to a deterioration of the current collection effect of the positive current collector, resulting in a rapid increase in the internal resistance of the button battery.Ultimately, the button battery can no longer meet the requirements of current application scenarios.

[0087] With the increasing market demand for button batteries capable of operating under high-speed centrifugal forces, it is required that button batteries function normally even under a centrifugal force of 3300g. However, in related technology, the displacement and offset of the positive assembly structure and the lack of elastic contact under a centrifugal force of 3300g lead to an increase in the internal resistance of the button battery. This affects the stability of the electrical performance of the button battery, making it impossible for the button battery to meet the requirements of current application scenarios.

[0088] To improve the stability of the electrical performance of button batteries in extreme application scenarios, the present application optimizes the internal structure of the button battery.

[0089] With reference to the Fig. 21 to Fig. 24, the second embodiment of the present application provides a button battery 1. This button battery 1 comprises a positive cover 11, a negative cover 12, a sealing ring 13, a positive current collector 14, a positive electrode foil 15, a negative electrode foil 16, a separator 17 and an electrolyte.

[0090] The positive cover 11 is designed as an open, lid-like structure. As in Fig. 21 and Fig. 22, the outer side of the positive cover 11 can be designed as a vertical structure. As shown in Fig. 23 and Fig. 24, the outer side of the positive cover 11 can also be provided with a raised structure.

[0091] The negative cover 12 is designed as an open, cover-like structure. The inner and outer diameters of the positive cover 11 are each larger than those of the negative cover 12, so that the positive cover 11 can cover the negative cover 12 from the outside.

[0092] The sealing ring 13 is arranged at the connection point between the positive cover 11 and the negative cover 12. The sealing ring 13 forms an enclosing structure around at least a portion of the wall of the negative cover 12, thus creating a sealed connection structure between the positive cover 11 and the negative cover 12. At the same time, the sealing ring 13 also serves to provide an insulating effect between the positive cover 11 and the negative cover 12.

[0093] The positive current collector 14 includes an annular bottom wall 141 and a side wall 143 connected circumferentially to the annular bottom wall 141. The annular bottom wall 141 and the side wall 143 together form a receiving space 144. A through hole 142 is formed on the annular bottom wall 141. The outer diameter of the positive current collector 14 is smaller than the inner diameter of the negative cover 12.

[0094] The positive electrode foil 15 is housed in the receiving space 144 of the positive current collector 14 and is in contact with the positive cover 11 through the through hole 142. During the cell assembly process, the positive electrode foil 15 is inserted into the inner region of the positive current collector 14, thereby forming the positive assembly 100.

[0095] The negative electrode foil 16 is housed in the interior of the negative cover 12. During the cell assembly process, the negative electrode foil 16 is inserted into the interior of the negative cover 12, thereby forming the negative assembly 500.

[0096] The separator 17 is arranged between the positive electrode foil 15 and the negative electrode foil 16 and serves to separate the positive electrode foil 15 from the negative electrode foil 16. The projection area of ​​the negative electrode foil 16 onto the separator 17 can substantially coincide with the projection area of ​​the positive electrode foil 15 onto the separator 17.

[0097] The electrolyte is injected into the inside of the button battery 1. After the injection of the electrolyte, the internal structure such as the negative electrode foil and the positive electrode foil are immersed in the electrolyte, and the charged ions in the positive and negative electrode foils are electrically connected to each other via the electrolyte.

[0098] With reference to the Fig. 21, Fig. 22 and Fig. 25, the button battery 1 further includes a washer 20, wherein the washer 20 includes an interconnected washer part 21 and a spring element portion 22, wherein the washer part 21 and the spring element portion 22 are arranged separately. The length of the washer part 21 is defined as L1, and the length of the spring element portion 22 is defined as L2, where L1>L2. The washer part 21 and the spring element portion 22 are cross-connected, whereby the two ends of the washer part 21 are connected to the positive current collector 14. The washer 20 further includes a raised structure 23 that passes through the through-hole of the positive current collector 14 and is attached to the positive electrode foil 15.The raised structure 23 may be arranged on the washer part 21, alternatively, the raised structure 23 may be arranged on the spring element section 22 or on both the spring element section 22 and the washer part 21. In the button battery, the positive electrode foil 15 is formed as a compacted powder structure, wherein the raised structure 23 may be directly embedded in the positive electrode foil 15.

[0099] By adding the washer 20 in the button battery 1, which is connected to the positive cap 11, the washer 20 comprising a cross-connected washer part 21 and a spring element portion 22, wherein the length L1 of the washer part 21 is greater than the length L2 of the spring element portion 22, the two ends of the washer part 21 are connected to the positive current collector 14. The spring element portion 22 is arranged in the positive current collector 14, and the raised structure 23, which is arranged either in the washer part 21, the spring element portion 22, or both, is further fixed in the positive electrode foil 15.Therefore, when the positive cover 11 is bulged outward, the washer 20 can further maintain the contact connection between the positive cover 11, the positive electrode foil 15 and the positive current collector 14, thereby improving the stability of the internal structure of the button battery 1.

[0100] With reference to the Fig. 21, Fig. 25, Fig. 26a and Fig. 27a, the washer part 21 comprises a washer main body 211 and a washer elevation 212 arranged to protrude relative to the washer main body 211. The washer elevation 212 and the washer main body 211 together define a washer receiving space 213. The washer receiving space 213 is configured to receive a part of the spring element section 22, whereby a stable connection structure can be established between the spring element section 22 and the washer part 21. It is understandable that when the spring element section 22 is directly connected to the washer main body 211 of the washer part 21, the spring element main body 211 protrudes relative to the washer main body 211.When the washer part 21 is connected to the positive current collector 14, the spring element section 22 arranged inside the current collector 14 must be completely embedded in the positive electrode foil 15, which significantly increases the assembly complexity between the washer 20 and the positive assembly 100. Therefore, a washer elevation 212 is provided on the washer part 21, which protrudes relative to the washer main body 211. The washer elevation 212 and the washer main body 211 together define the washer receiving space 213 into which the spring element section 22 is inserted. This allows the washer main body 211 and the spring element main body 221 to be arranged in the same plane, which significantly reduces the assembly complexity between the washer 20 and the positive assembly 100.

[0101] In other possible embodiments, as in Fig. 27d, the spring element section 22 comprises a spring element base body 221 and a spring element elevation 223 arranged protruding relative to the spring element base body 221. The spring element elevation 223 and the spring element base body together define a spring element receiving space 224. This spring element receiving space 224 is configured to receive a part of the washer part 21.

[0102] With reference to the Fig. 26a, Fig. 26b, Fig. 26c, Fig. 27a, Fig. 27b and Fig. 27c, the thickness of the spring element section 22 is denoted by t1 and the height of the washer elevation 212 is denoted by H1, where: H1 ≥ t1. The width of the spring element section 22 is denoted by w1 and the width of the washer elevation 212 is denoted by w2, where: w2 = (1.05 ~ 1.3) · w1.

[0103] Through investigations, the inventors found that when the height H1 of the washer protrusion 212 and the thickness t1 of the spring element portion 22 satisfy the condition H1 ≥ t1, the spring element portion 22 can be fully accommodated in the washer receiving space 213 defined by the washer protrusion 212. When the height H1 of the washer protrusion 212 and the thickness t1 of the spring element portion 22 satisfy the condition H1 < t1, at least a portion of the spring element portion 22 will protrude relative to the washer main body 211 of the washer part 21. This causes the washer 20 to occupy more space inside the button battery 1.

[0104] The inventors have found through research that the width w2 of the washer raised portion 212 and the width w1 of the spring member portion 22 must satisfy the following relationship: w2 = (1.05~1.3) w1. Only in this way can the spring member portion 22 be fully accommodated in the washer receiving space 213 defined by the washer raised portion 212 in the width direction, and a sufficient assembly clearance can be formed between the spring member portion 22 and the washer raised portion 212. If the width w2 of the washer raised portion 212 is smaller than 1.05 w1, when both the spring element portion 22 and the washer part 21 are made of a hard material, a part of the spring element portion 22 cannot be installed in the washer receiving space 213 defined by the washer raised portion 212.If the width w2 of the washer raised portion 212 is larger than 1.3 w1, the mounting distance between the spring member portion 22 and the washer raised portion 212 becomes too large, thereby unnecessarily wasting the internal space of the button battery 1.

[0105] Similarly, if a spring element elevation portion 223 is provided on the spring element portion 22, which, together with the spring element main body 221, forms the spring element receiving space 224, and if a part of the washer part 21 is accommodated in the spring element receiving space 224, then the thickness of the washer part 21 is denoted by t2. In this case, the height of the spring element elevation portion 223 is not less than the thickness t2 of the washer part 21. The width of the washer part 21 is denoted by w3, where the width ratio between the spring element elevation portion 223 and the washer part 21 is in the range of (1.05~1.3).

[0106] If the height of the spring element raised portion 223 and the thickness t2 of the washer part 21 do not meet the above-mentioned size requirements, at least a portion of the washer part 21 protrudes in the thickness direction relative to the spring element main body 221 of the spring element portion 22. This results in the washer 20 occupying more space in the interior of the button battery 1.

[0107] If the size ratio between the height of the spring element elevation portion 223 and the width w3 of the washer part 21 is outside the range of 1.05 to 1.3, the washer cannot be mounted in the spring element receiving space 224 defined by the spring element elevation portion 223. Alternatively, the mounting distance between the washer and the spring element elevation portion 223 is too large, resulting in waste of the internal space of the button battery 1.

[0108] With reference to Fig. 27c, the thickness t1 of the spring element portion 22 satisfies the condition: 0.05 mm ≤ t1 ≤ 0.30 mm. In a specific embodiment, the thickness t1 of the spring element portion 22 may be 0.05 mm, 0.1 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, and any value between two of these values, or a range between two of these values. Through research, the inventor found that if the thickness t1 of the spring element portion 22 is less than 0.05 mm, the strength of the entire spring element portion 22 is insufficient, whereby the spring element portion 22 cannot be stably embedded in the positive electrode foil. When the thickness t1 of the spring element portion 22 is larger than 0.30 mm, the overall size of the spring element portion 22 becomes relatively large, resulting in the washer 20 occupying a larger internal space of the button battery.Through further investigations, the inventor has found that the thickness t1 of the spring element portion 22 can be set to 0.10 mm to 0.20 mm in some embodiments, whereby the spring element portion 22 can be optimized simultaneously in terms of both strength and size distribution.

[0109] With reference to Fig. 26c, the thickness t2 of the washer part 21 satisfies the condition: 0.05 mm ≤ t2 ≤ 0.30 mm. In a concrete embodiment, the thickness t2 of the washer part 21 can be 0.05 mm, 0.1 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, and any value between two of these values, or a range between two of these values. Through research, the inventor found that when the thickness t2 of the washer part 21 is less than 0.05 mm, the strength of the entire washer part 21 is insufficient, causing the washer part 21 to be unable to be stably embedded in the positive electrode foil. When the thickness t2 of the washer part 21 is larger than 0.30 mm, the overall size of the washer part 21 becomes relatively large, resulting in the washer assembly occupying more internal space of the button battery.Through further investigations, the inventor has found that the thickness t2 of the washer part 21 can be set to 0.10 mm to 0.20 mm in some embodiments, whereby the washer part 21 can be optimized simultaneously in terms of both strength and size distribution.

[0110] The thickness t2 of the washer part 21 and the thickness t1 of the spring element section 22 can be set differently as long as they meet the specified size requirements. Further investigations have shown that in some embodiments, the thickness t2 of the washer part 21 and the thickness t1 of the spring element section 22 can be set to be the same, thereby evenly distributing the strength at different locations of the washer 20 formed by the connection of the washer part 21 and the spring element section 22, promoting a stable connection between the male assembly and the female cover assembly.

[0111] Suitable materials for manufacturing the washer part 21 or the spring element portion 22 include stainless steel materials. Suitable stainless steel materials include at least one of SUS44, SUS304, SUS430, SUS316, and SUS444. The washer part 21 and the spring element portion 22 can be made of different but similar-performance stainless steel materials. In some embodiments, the washer part 21 and the spring element portion 22 are both made of SUS430, making both the washer part 21 and the spring element portion 22 themselves magnetic. This facilitates the connection between the washer part 21 and the spring element portion 22 by welding, reduces welding difficulties between them, and improves the stability of the welded joint.It is understood that the use of the same stainless steel material for the washer part 21 and the spring element section 22 helps to prevent the occurrence of a potential difference between the washer part 21 and the spring element section 22.

[0112] With reference to Fig. 28, the spring element portion 22 is welded to the washer part 21 to form the washer 20. The number of second welds 241 between the spring element portion 22 and the washer part 21 is an even number. For example, the number of second welds 241 may be two, four, six, or eight. In some embodiments, the number of second welds 241 is set to two.

[0113] Through research, the inventors have found that single-spot welding or an odd number of second welding points 241 (greater than 1) between the spring element portion 22 and the washer part 21 may result in insufficient welding strength between the spring element portion 22 and the washer part 21. This may further cause the relative position between the spring element portion 22 and the washer part 21 to shift. In addition, when three-point or four-point welding is used between the spring element portion 22 and the washer part 21, the cost of the welding process increases, which affects production efficiency. Therefore, in a specific embodiment, the number of welding points between the spring element portion 22 and the washer part 21 is set to two.

[0114] Furthermore, with reference to Fig. 28, the welding area formed by the connection between the spring element section 22 and the washer part 21 is defined as the circular welding area Q5. The distance between the two second welding points 241 is defined as the diameter of the circular welding area Q5. The center of the circular welding area Q5 coincides with the center of the washer 20. The diameter of the circular welding area Q5 is not greater than the width w1 of the spring element section 22 and less than the width w3 of the washer part 21.

[0115] The spring element section 22 and the washer part 21 together form the circular welding area Q5, the center of which coincides with the center of the washer 20. This ensures a stable weld connection between the spring element section 22 and the washer part 21 and promotes the formation of a centered symmetrical structure of the washer 20.

[0116] The diameter of the circular welding area Q5 is set to be no larger than the width w1 of the spring element portion 22 and no larger than the width w3 of the washer part 21. Therefore, the circular welding area Q5 is located substantially in the central intersection area between the spring element portion 22 and the washer part 21, without causing a problem of asymmetry of the spring element portion 22 and the washer part 21 with respect to the center of the washer 20 after welding.

[0117] With reference to Fig. 22, Fig. 25, Fig. 27a and Fig. 30, the raised structure 23 includes a first flange 231 and a second flange 232 disposed on the spring element portion 22. The first flange 231 is located at one end of the spring element portion 22, while the second flange 232 is disposed at the other end of the spring element portion 22.

[0118] The above-mentioned first flange 231 and the second flange 232 are each embedded in the positive electrode foil 15. Therefore, the distance between the first flange 231 and the second flange 232 is designed so that the effective range of the positive electrode foil 15 can be restricted by the washer 20 as a whole. When the first flange 231 and the second flange 232 are arranged in the center of the spring element portion 22, the effective range of the positive electrode foil 15 associated with the first flange 231 and the second flange 232 becomes relatively small. This reduces the restricting effect of the washer 20 on the positive electrode foil 15.

[0119] With reference to Fig. 27c, the first flange 231 and the second flange 232 are arranged symmetrically to the center of the washer 20. The height by which the first flange 231 and the second flange 232 protrude relative to the spring element base body 221 is the same and amounts to h1. In some embodiments, the height h1 of the first flange 231 or the second flange 232 with respect to the thickness t1 of the spring element portion 22 satisfies the condition: 2 t1 ≤ h1 ≤ 10 t1.

[0120] In some embodiments, h1 may take the following values: 2t1, 3t1, 4t1, 5t1, 6t1, 7t1, 8t1, 9t1, 10t1 and any value or range between two of the mentioned values.

[0121] Through research, the inventor found that when the height h1 of the first flange 231 or the height h1 of the second flange 232 satisfies the condition 2 t1 ≤ h1 ≤ 10 t1, the positive electrode foil 15 is not damaged when embedding the first flange 231 or the second flange 232, thus preventing defective foils or powder loss. Furthermore, no deformation occurs when embedding the first flange 231 and the second flange 232 into the positive electrode foil 15.

[0122] With reference to Fig. 30a, if the height of the first flange 231 or the height of the second flange 232 is h1 < 2t, the integration of the first flange 231 or the second flange 232 into the positive electrode foil 15 is insufficient. When the positive cover 11 is bulged outward, the first flange 231 or the second flange 232 tends to detach from the positive electrode foil 15, resulting in poor contact between the washer 20 and the positive current collector 14.

[0123] With reference to Fig. 30b, when the height of the first flange 231 or the height of the second flange 232 is h1 > 10t1, the first flange 231 and the second flange 232 need to be embedded deeper into the positive electrode foil 15. As a result, during the embedding of the first flange 231 or the second flange 232 into the positive electrode foil 15, the washer 20 is easily deformed, and the entire structure of the positive electrode foil 15 is also easily damaged.

[0124] With further reference to Fig. 29a, the extension line of the outer edge of the first flange 231 or the second flange 232 forms the same angle with the plane of the spring element base body 221, which angle is referred to as θ1. θ1 satisfies the condition: 90°≤θ1≤150°.

[0125] In the specific embodiment, the first flange 231 and the second flange 232 are arranged symmetrically with respect to the center of the washer 20. The angle formed by the extension line of the outer edge of the first flange 231 with the plane of the spring element main body 221 is the same as the angle formed by the extension line of the outer edge of the second flange 232 with the plane of the spring element 22, both angles being referred to as θ1. θ1 must satisfy the condition 90°≤θ1≤150°. For example, θ1 can be 90°, 100°, 110°, 120°, 130°, 140°, 150°, or any angle between two of these values, or a range between two of these angles.

[0126] Through research, the inventor found that when θ1 is <90°, the first flange 231 or the second flange 232 is difficult to be embedded in the positive electrode foil 15. When θ1 is >150°, the area where the first flange 231 or the second flange 232 is embedded in the positive electrode foil 15 is too large, which can easily damage the overall structure of the positive electrode foil 15, resulting in the foil peeling.

[0127] With reference to the Fig. 29a, the first flange 231 or the second flange 232 may be formed as a straight edge slope structure. Alternatively, as in Fig. 9b, the first flange 231 or the second flange 232 may also be formed as a wave-shaped inclination structure. Or, as shown in Fig. 9c, the first flange 231 or the second flange 232 may also be formed as an inclination structure with an acute angle structure formed at the end portion.

[0128] With reference to Fig. 21 and Fig. 26a, the raised structure 23 further comprises a washer raised portion 212 arranged on the washer part 21, wherein the washer raised portion 212 protrudes through the through-hole 142 and is embedded in the positive electrode foil 15. The washer raised portion 212 is located substantially in the central position of the washer main body 211. The washer raised portion 212 protrudes relative to the plane of the washer main body 211. The washer raised portion 212 defines and forms a washer receiving space 213, which serves to receive at least a portion of the spring element portion 22. The washer raised portion 212 can be embedded in the positive electrode foil 15, thereby providing a fixing function for the positive electrode foil 15.

[0129] The washer part 21 and the spring element portion 22 form the washer 20 by welding. The washer ridge 212 forms a structure similar to a reinforcing rib portion on the spring element portion 22. Consequently, the washer ridge 212 has higher strength after being embedded in the positive electrode foil 15. The washer ridge 212, together with the spring element portion 22, forms a ridge structure with high embedding strength, so that the above-mentioned ridge structure can maintain strong contact with the positive electrode foil 15. As a result, when the positive cover 11 bulges outward, the problem of the positive cover 11 separating from the positive electrode foil 15, which would result in poor contact, does not easily occur.

[0130] Furthermore, when the washer part 21 and the spring element portion 22 are formed as an integral structure, the strength of the washer protrusion 212 is lower because no spring elements are accommodated in the washer receiving space 213 defined by the washer protrusion 212. If the height H1 of the washer protrusion 212 is relatively high, this may cause the washer protrusion 212 to be easily deformed when embedded in the positive electrode foil 15.However, if the height H1 of the washer protrusion 212 is relatively small, although the strength of the washer protrusion 212 can be increased, this may result in the washer protrusion 212 not being able to be embedded in the positive electrode foil 15, or the embedding depth of the washer protrusion 212 in the positive electrode foil 15 being insufficient, whereby an effective fixing function cannot be provided.

[0131] With reference to the Fig. 31, the orthogonal projection of the washer 20 onto the positive cover 11 is arranged in a cross-shaped structure ("+" shape), with the washer part 21 and the spring element section 22 each being shown as a linear projection onto the positive cover 11. Both the washer 20 and the positive cover 11 are designed as centrally symmetrical structures, with the center of the washer 20 substantially coinciding with the center of the positive cover 11.

[0132] The arrangement of the washer 20 in a cross-shaped structure, with the washer part 21 and the spring element section 22 shown as a linear projection onto the positive cover 11, facilitates the connection of the two ends of the longer washer part 21 of the washer 20 to the positive current collector 14. At the same time, the shorter spring element section 22 of the washer 20 is located within the positive current collector 14.

[0133] The cross-shaped structure of the washer 20 may be a regular cross-shaped structure as shown in Fig. 31. Alternatively, the cross-shaped structure of the washer 20 may also be an irregular cross-shaped structure, as in Fig. 32a, in which the two ends of the washer part 21 are designed as arcuate structures. Alternatively, as in Fig. 32b, the washer base body 211 comprises two sections of the washer base body 211, which are each located on the two sides of the washer elevation 212, wherein both sections of the washer base body 211 are designed as sector-shaped structures.

[0134] With reference to Fig. 31, Fig. 33 and Fig. 34, the washer 20 is welded onto the positive cover 11, wherein both the washer 20 and the positive cover 11 are designed as centrally symmetrical structures and the coaxiality between the washer 20 and the positive cover 11 does not exceed 0.3 mm.

[0135] During the welding process between the washer 20 and the positive cap 11, the coaxiality between the washer 20 and the positive cap 11 must be controlled to no more than 0.3 mm. In some embodiments, the coaxiality between the washer 20 and the positive cap 11 is no more than 0.1 mm. The inventor has found through research that when the coaxiality between the positive cap 11 and the washer 20 is more than 0.3 mm, a significant displacement occurs between the washer 20 and the positive cap 11. This further leads to a significant displacement between the washer 20 and the current collector 14, which in turn impairs the current collection efficiency of the positive current collector 14 and ultimately adversely affects the electrical characteristics of the button battery 1.

[0136] With reference to Fig. 31, the number of third welding points 242 formed by welding between the washer 20 and the positive cover 11 is at least two, wherein at least two of the third welding points 242 are arranged symmetrically to the center of the washer 20.

[0137] Through research, the inventor found that the number of third welds 242 formed by welding between the washer 20 and the positive cover 11 is set to two. Two third welds 242 contribute to increasing the welding strength between the washer 20 and the positive cover 11. If the number of third welds 242 formed by welding between the washer 20 and the positive cover 11 is only one, it easily leads to positional deviation and edge warping of the washer 20 relative to the positive cover 11. If the number of third welds 242 formed by welding between the washer 20 and the positive cover 11 is more than two, the welding process between the washer 20 and the positive cover 11 becomes more complicated, which simultaneously increases the welding cost.

[0138] With reference to the Fig. 31 and Fig. 35, by optimizing the position of the welding areas between the washer 20 and the positive cover 11, the stability performance of the button battery 1 can be further improved.

[0139] The welding-suitable base body of the washer 20 is divided into five regions, namely the first region Q1, the first sub-region Q2a, the second sub-region Q2b, the third sub-region Q3a, and the fourth sub-region Q3b. The first region Q1 is defined as the welding region of the washer part 21 and the spring element part 22. The first sub-region Q2a and the second sub-region Q2b are arranged on both sides of the first region Q1 and are located on the washer part 21. The third sub-region Q3a and the fourth sub-region Q3b are arranged on both sides of the first region Q1 and are located on the spring element part 22.

[0140] The position of the third welds 242 between the washer 20 and the positive cover 11 can be arranged on the first sub-area Q2a and the second sub-area Q2b. The position of the third welds 242 between the washer 20 and the positive cover 11 is outside the third sub-area Q3a and the fourth sub-area Q3b.

[0141] The inventor has determined through research that when the position of the third weld 242 between the washer 20 and the positive cap 11 is located above the third sub-region Q3a and the fourth sub-region Q3b, the third sub-region Q3a and the fourth sub-region Q3b of the washer 20 lose their elasticity. When the positive cap 11 bulges outward, since the region where the first flange 231 and the second flange 232 of the washer 20 are located is welded to the positive cap 11, this results in the first flange 231 and the second flange 232 being separated from the positive electrode foil 15. This, in turn, results in the washer 20 as a whole not having good contact with the positive electrode foil 15, thereby invalidating the restraining effect of the first flange 231 and the second flange 232 on the positive electrode foil 15.It should be noted that the first region Q1 is formed as a welding region between the washer part 21 and the spring element section 22 and therefore can no longer be used as a welding region between the washer 20 and the positive cover 11.

[0142] As in Fig. 27b, Fig. 31 and Fig. As shown in Figure 35, the distance d1 between at least two third welds 242 is defined as follows: 0.3 L1 + 0.7 w1 ≤ d1 ≤ 0.9 L1 + 0.1 w1. Where L1 represents the length of the washer portion 21 and w1 represents the width of the spring element portion 22.

[0143] The inventor has determined through research that to ensure the consistency of the performance of the washer 20 after welding to the positive cover 11, two third welding points 242 are provided between the washer 20 and the positive cover 11, with the two third welding points 242 being arranged symmetrically to the center of the washer 20. Furthermore, to ensure the application of the button battery at high temperatures, it is required that the washer 20 be bonded to the positive assembly and that the washer 20 be bonded to the positive cover 11 without a non-contact gap forming between them when the positive cover 11 has an outward bulge. Therefore, the distance d1 between the two third welding points 242 must be satisfied as follows: 0.3 L1 + 0.7 w1 ≤ d1 ≤ 0.9 L1 + 0.1 w1. As shown in Fig. 35, Fig. 36a and Fig. 36b, L3=0.3 L1+0.7 w1, L4=0.9 L1+0.1 w1, where L3≤d1≤L4. If the distance d1 between the two third welds 242 is too large, that is, if d1 is greater than 0.9 L1+0.1 w1, the position of the third weld 242 is close to the edge of the washer 20. As a result, the welding strength between the washer 20 and the positive cover 11 is low, so that when the positive cover 11 bulges outward, the washer 20 easily detaches from the positive cover 11, resulting in a connection failure between the washer 20 and the positive cover 11. As shown in Fig. 36a and Fig. 36b, when the distance d1 between the two third welding points 242 is too small, that is, when d1 is less than 0.3 L1 + 0.7 w1, the position of the third welding point 242 is close to the circle center of the positive cover 11. When the positive cover 11 has an outward bulge, the washer 20 follows the bulge of the positive cover 11, resulting in the washer 20 being easily separated from the positive electrode foil 15. This results in the restricting effect of the washer 20 on the positive electrode foil 15 being canceled, resulting in poor contact between the positive electrode foil 15 and the positive cover 11.

[0144] With reference to the Fig. 35, Fig. 37 and Fig. 38, the positive current collector 14 includes an annular bottom wall 141. The annular bottom wall 141 defines a through hole 142. Both ends of the washer part 21 are connected to the annular bottom wall 141, so that the two ends of the washer part 21 are sandwiched between the annular bottom wall 141 and the positive cover 11. The positive electrode foil 15 disposed within the positive cover 11 is in contact with the positive cover 11 through the through hole 142.

[0145] With reference to the Fig. 37 to Fig. 41 and Fig. 42a, the diameter of the circumcircle corresponding to the edge of the washer part 21 is defined as D1, and the diameter of the circumcircle corresponding to the edge of the spring element portion 22 is defined as D2. The washer part 21 includes oppositely disposed first end portions 2141 and second end portions 2142. The first end portion 2141 includes two first end points 2143. The angle between the connecting line of the two first end points 2143 and the center of the washer 20 is 2θ2. The diameter of the through hole 142 of the positive current collector 14 is defined as D3, the outer diameter of the annular bottom wall 141 of the positive current collector 14 is defined as D4, and the thickness of the positive current collector 14 is defined as t3. The length L1 of the washer part 21 satisfies the following condition: L1 = D1 · cosθ2, where 1.02 · D3 · cosθ2 ≤ L1 ≤ 0.98 · (D4 - 2t3) · cosθ2.

[0146] In order to ensure that the two ends of the washer part 21 remain in contact with the annular bottom wall 141 of the positive current collector 14 at the beginning and after the sealing of the button battery 1, and the two ends of the washer part 21 continue to rest on the annular bottom wall 141 of the positive current collector 14 after the sealing of the button battery 1, the inventors have found through research that the following condition is satisfied in some embodiments: 1.02 · D3 · cosθ2 ≤ L1 ≤ 0.98 · (D4 - 2t3) · cosθ2.

[0147] With reference to the Fig. 42b, when the length of the washer part 21 is defined as L1a and L1a > 0.98 · (D4 - 2t3) · cosθ2, at least a portion of the end of the washer part 21 is located outside the region Q4 in which the annular bottom wall 141 of the positive current collector 14 lies. This protruding region is shown as the protruding region 21a, while the other end of the washer part 21 has no contact with the region Q4 in which the annular bottom wall 141 lies, like the non-protruding region 21b in Fig. 42b shows. During the sealing process of the button battery 1, the edge strength of the positive current collector 14 exceeds the strength of the plane in which the annular bottom wall 141 of the positive current collector 14 is located. The height of the protruding portion 21a of the washer part 21, which protrudes beyond the edge of the positive current collector 14, is greater than the height of the non-protruding portion 21b of the washer part 21, which does not protrude beyond the edge of the positive current collector 14. This creates a height difference inside the positive current collector 14, resulting in a deterioration in the collector efficiency of the positive current collector 14.

[0148] As in Fig. 42c, when the length L1b of the washer part 21 is set such that L1b < 1.02 D3 cosθ2, the area where one end of the washer part 21 is located is in the area where the through hole 142 of the positive current collector 14 is located, namely, the protruding area 41c, as shown in Fig. 42c. The other end of the washer part 21 is located in the area Q4 in which the annular bottom wall 141 of the positive current collector 14 is located, as in the non-projecting area 21d in Fig. 42c. During the sealing process of the button battery 1, one end of the washer part 21 is located in a region higher in height than the through-hole 142 of the positive current collector 14, which corresponds to the protruding region 21c. In contrast, the other end of the washer part 21 is located in a region at the level of the annular bottom wall 141 of the positive current collector 14, which corresponds to the non-protruding region 21d. This creates a height difference inside the positive current collector 14, resulting in a deterioration in the collecting effect of the positive current collector 14.

[0149] With reference to Fig. 39 to Fig. 42, the spring element portion 22 comprises a first spring element end portion 2221 and a second spring element end portion 2222. The first spring element end portion 2221 comprises two spring element end points 2223, wherein the angle between the connecting line of the two spring element end points 2223 and the center of the washer 20 is 2θ3. The length L2 of the spring element portion 22 satisfies the condition: 1.5·w3≤L2≤0.98·D3·cosθ3, where w3 is the width of the washer part 21 and D3 is the inner diameter of the through hole 142.

[0150] During the packaging process of the button battery 1, the first flange 231 and the second flange 232 of the spring element portion 22 are embedded in the positive electrode foil 15, thereby positioning the positive electrode foil 15. To ensure that the first flange 231 and the second flange 232 of the spring element portion 22 remain embedded in the positive electrode foil 15 and maintain elastic connection therewith even when there is a positional deviation between the washer 20 and the positive current collector 14 or when the positive cap 11 warps, it was determined through research that the length L2 of the spring element portion 22 must satisfy the condition: 1.5·w3≤L2≤0.98·D3·cosθ3.

[0151] If the length L2 of the spring element portion 22 exceeds 0.98·D3·cosθ3, a larger relative positional deviation occurs between the washer 20 and the positive current collector 14. This results in one or both of the flanges 231, 232 no longer being able to be embedded in the positive electrode foil 15. If the length L2 of the spring element portion 22 is less than 1.5·w3, the first flange 231 and the second flange 232 move with the outward movement of the positive cover 11 as it bulges outward. As a result, one or both flanges 231, 232 may be detached from the positive electrode foil 15. This causes the washer 20 to lose its elastic positioning function with respect to the positive current collector 14, and poor contact between the washer 20 and the positive current collector 14 occurs.

[0152] The present application example also provides a manufacturing method of a washer 20 for the button battery 1. With reference to the Fig. 43a, Fig. 43b and Fig. 43c, the manufacturing process of the washer 20 comprises the following steps:

[0153] By means of a stamping process, a band-shaped structure consisting of a plurality of interconnected washer sets 400 is produced, wherein adjacent washers are connected to each other in the form of material connecting edges, as in Fig. 43a;

[0154] By means of a stamping process, a band-shaped structure consisting of several interconnected spring element combinations 300 is produced, wherein adjacent spring elements are connected to each other in the form of material connecting edges, as in Fig. 43b;

[0155] After adjusting the spring element combination 300 and the washer set 400 to center both components, the spring element combination 300 and the washer set 400 are welded together using a laser welding system, creating a structure consisting of several interconnected washer assemblies. Adjacent washer assemblies are connected to each other by material connection edges, as shown in Fig. 43c.

[0156] Compared with a method in which a single washer and a single spring element are individually welded together to manufacture the washer 20, the above-described method for manufacturing the washer 20 effectively increases the production efficiency of the washer 20 and reduces the cost of the assembly process.

[0157] The application also provides a method of assembling a button battery, comprising the following steps: Step 1: The washer assembly described above, which exists as a continuous unit, is separated by cutting into a single washer assembly; Step 2: After adjusting the relative position of the washer assembly and the positive cover, the washer assembly and the positive cover are welded together to form a positive cover assembly, as shown in Fig. 44 shown; Step 3: The positive electrode foil is inserted into the positive current collector to form a positive assembly; Step 4: The negative electrode foil is inserted into the negative cover to form a negative cover assembly; Step 5: Inside the negative lid assembly, a separator and the positive assembly are inserted one after the other to form an assembly; Step 6: Electrolyte is injected into the above assembly; Step 7: The positive cap assembly is placed on the ends of the above-mentioned assembly, the assembly is sealed, and the button battery is formed through formation.

[0158] It should be noted that the order of the individual steps in the above-mentioned manufacturing method can be adapted depending on the requirements of the actual assembly process and is not limited to the order described in the above-mentioned embodiments.

[0159] This application further provides a specific embodiment 2 and comparative examples 3 to 6. High-temperature storage tests of the button batteries 1 provided in embodiment 2 and comparative examples 3 to 6 further verify the change in internal resistance of the batteries under high-temperature conditions. Example 2

[0160] With reference to Fig. 44a, the button battery provided in embodiment 2 comprises a washer 20, the structure of which in Fig. 25. Both the base body of the washer and the base body of the spring element have a rectilinear structure. The length L1 of the washer satisfies the condition: L1 = 0.91 · (D4 - 2t3) · cosθ2, the length L2 of the spring element satisfies the condition: L2 = 0.72 · D3 · cosθ3, the thickness t2 of the washer or the thickness t1 of the spring element satisfies the condition: t1 = t2 = 0.10, the angle θ1 of the first or second flange satisfies the condition: θ1 = 120°, and the height h1 of the first or second flange satisfies the condition: h1 = 4 · t1. Comparison example 3

[0161] With reference to Fig. 44c, the button battery provided in Comparative Example 3 comprises a washer 20, the structure of which is shown in Fig. 25. Both the base body of the washer and the base body of the spring element have a rectilinear structure. The length L1 of the washer satisfies the condition: L1 = 0.91 · (D4 - 2t3) · cosθ2, the length L2 of the spring element satisfies the condition: L2 = 0.72 · D3 · cosθ3, the thickness t2 of the washer or the thickness t1 of the spring element satisfies the condition: t1 = t2 = 0.10, the angle θ1 of the first or second flange satisfies the condition: θ1 = 120°, and the height h1 of the first or second flange satisfies the condition: h1 = 10 · t1. Comparison example 4

[0162] With reference to Fig. 44b, the button battery provided in Comparative Example 4 comprises a washer 20, the structure of which is shown in Fig.25. Both the washer base body and the spring element base body have a linear structure. The length L1 of the washer corresponds to the formula: L1 = 0.91 · (D4 - 2t1) · cosθ2, and the length L2 of the spring element corresponds to the formula: L2 = 0.72 · D3 · cosθ3. The thickness t2 of the washer or the thickness t1 of the spring element satisfies the condition: t1 = t2 = 0.10. The angle θ1 of the first or second flange satisfies the condition: θ1 = 120°, and the height h1 of the first or second flange satisfies the condition: h1 = 2t1. Comparison example 5

[0163] The button battery provided in Comparative Example 5 comprises a washer 20, the structure of which is Fig.25. Both the washer base body and the spring element base body have a linear structure. The length L1 of the washer corresponds to the formula: L1 = (D4 - 2t1) · cosθ2, and the length L2 of the spring element corresponds to the formula: L2 = 0.72 · D3 · cosθ3. The thickness t2 of the washer or the thickness t1 of the spring element satisfies the condition: t1 = t2 = 0.10. The angle θ1 of the first or second flange satisfies the condition: θ1 = 120°, and the height h1 of the first or second flange satisfies the condition: h1 = 4t1. Comparison example 6

[0164] The button battery provided in Comparative Example 6 comprises a washer 20, the structure of which is Fig.25. Both the washer base body and the spring element base body have a linear structure. The length L1 of the washer corresponds to the formula: L1 = 0.90 D3 cosθ2, and the length L2 of the spring element corresponds to the formula: L2 = 0.72 D3 cosθ3. The thickness t2 of the washer or the thickness t1 of the spring element satisfies the condition: t1 = t2 = 0.10t. The angle θ1 of the first or second flange satisfies the condition: θ1 = 120°, and the height h1 of the second flange satisfies the condition: h1 = 4t1. High temperature storage test (evaluation of internal resistance):

[0165] The high-temperature storage test described below is performed on the button batteries of Embodiment 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 obtained in the above-described order to evaluate the change in internal resistance under high-temperature conditions.

[0166] Specifically, first, the internal resistance (Ω) between the positive electrode and the negative electrode of the button batteries obtained according to Embodiment 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 was measured using the same method. This value is referred to as the initial resistance (Ω) and is shown in Table 2 below. Subsequently, the button batteries of Embodiment 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 were stored in a high-temperature oven. The internal temperature of the high-temperature oven was set to 125°C, and the storage period was one week.After one week of storage, the internal resistance (Ω) between the positive electrode and the negative electrode of the button batteries of Embodiment 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 was measured again using the same method. This value is referred to as the internal resistance (Ω) after one week of storage and is shown in Table 2 below. Table 2 project Flange height e h1 Length of washer L1 Internal resistance (Ω) Internal resistance increase rate Initially After one week of storage Example 2 4t1 0.91·(D4-2t1)·cosθ2 3.259 6.421 97% Comparison example 3 10t1 0.91·(D4-2t1)·cosθ2 12.461 21.396 72% Comparison example 4 2t1 0.91·(D4-2t1)·cosθ2 3.891 14.991 285% Comparison example 5 4t1 (D4-2t1)·cosθ2 3.459 6.881 160% Comparison example 6 4t1 0.90 D3 cosθ2 3.169 10.869 216% Evaluation results:

[0167] As shown in Table 2, Embodiment 2 is compared with Comparative Example 3. The height h1 of the first flange or the second flange of the washer of the button battery of Embodiment 2 is set to 4t1, while the initial internal resistance is 3.259 Ω. In comparison, the height h1 of the first flange or the second flange of the washer of the button battery of Comparative Example 3 is set to 10t1. The initial internal resistance of the button battery of Embodiment 2 is significantly better than that of the button battery of Comparative Example 3. After disassembling the cells, it was found that the initial internal resistance of the button battery of Comparative Example 3 is significantly higher than that of the button battery of Embodiment 2.The reason for this is that the first flange or the second flange of the button battery of Comparative Example 3 deforms after insertion into the positive electrode foil, and particles of the positive electrode foil fall off. This leads to poor internal contact, causing the initial internal resistance of the button battery of Comparative Example 3 to be significantly higher than that of the button battery of Embodiment 2.

[0168] As shown in Table 2, Embodiment 2 is compared with Comparative Example 4. The height h1 of the first flange or the second flange of the washer of the button battery of Embodiment 2 is set to 4t1, while the height h1 of the first flange or the second flange of the washer of the button battery of Comparative Example 4 is set to 2t1. The initial internal resistance of the button battery of Embodiment 2 is not significantly different from that of the button battery of Comparative Example 4. However, after one week of storage at a high temperature of 125°C, the increase rate of the internal resistance of the button battery of Comparative Example 4 is significantly higher than that of the button battery of Embodiment 2.CT (computed tomography) image analysis of the button battery revealed that a portion of the first flange or the second flange of the washer assembly of the button battery of Comparative Example 4 was peeling off from the positive electrode foil. This resulted in poor internal contact of the button battery during high-temperature storage.

[0169] The results of the above-described embodiments and comparative examples show that by setting the height h1 of the first flange or the second flange of the washer of the button battery according to the conditions specified in this application, the internal contact within the battery can be improved. This achieves an increase in the stability of the battery. Furthermore, in a high-temperature environment, poor internal contact caused by bulging of the positive cap can be effectively prevented, so that the characteristics of the button battery are not deteriorated and the stability of the battery's electrical performance is higher.

[0170] Comparing Embodiment 2 with Comparative Example 5, it is clear that the length of the washer portion of the button battery washer in Embodiment 2 is set to 0.91 (D4 - 2t1) cosθ2, while the length of the washer portion of the button battery washer in Comparative Example 5 is set to (D4 - 2t1) cosθ2. From the data in Table 2, although the initial internal resistance of the button battery in Comparative Example 5 is close to that of Embodiment 2 when the washer portion length is too long, after one week of storage at 125°C, the increase in the internal resistance of the button battery in Comparative Example 5 is significantly greater than the increase in the internal resistance of the button battery in Embodiment 2.Observing the external appearance of the button battery of Comparative Example 5 and the button battery of Embodiment 2, it was found that the positive cap of the button battery of Comparative Example 5 has prominent depressions and protrusions. CT scan analysis of the button battery of Comparative Example 5 and the button battery of Embodiment 2 revealed that, at the protrusion portion of the positive cap of the button battery of Comparative Example 5, the length of the washer portion protrudes beyond the positive current collector. From this, it can be analyzed that when a portion of the length of the washer portion protrudes beyond the positive current collector, a rib-like structure is formed between the washer portion and the positive current collector.This results in the tightness of the seal between the washer and the positive current collector varying at different positions during battery sealing, resulting in bulging of the positive cap of the battery. As a result, the internal resistance of the button battery becomes unstable after high-temperature storage, and the internal resistance increases.

[0171] Comparing Embodiment 2 with Comparative Example 6, the length of the washer portion of the button battery washer in Embodiment 2 is 0.91 (D4-2t1) cosθ2, while the length of the washer portion of the button battery washer in Comparative Example 6 is 0.90 D3 cosθ2. From the data in Table 2, it can be seen that when the washer length is too short, although the initial internal resistance of the button battery of Comparative Example 6 is close to that of Embodiment 2, the internal resistance increase of the button battery of Comparative Example 6 after one week of storage at 125°C increases to 216%, which is significantly higher than the internal resistance increase of the button battery of Embodiment 2.First, the button battery of Comparative Example 6 was observed using CT technology. It was found that one side of the washer part was not positioned in the area Q4 where the annular bottom wall of the positive current collector is located. Furthermore, there was a fine gap between the washer part and the positive current collector at the outwardly bulging portion of the positive cap. After disassembling the battery, it was found that one side of the washer part was not positioned in the fourth area Q4 of the positive current collector, and the washer part was partially separated from the positive electrode foil, resulting in poor contact and an increase in internal resistance.

Claims

[1] Button battery (1), comprising: a positive cover assembly (220) comprising a positive cover (11) and a washer (20), the washer (20) being arranged inside the positive cover (11); a positive current collector (14) arranged inside the positive cover (11) and having a receiving space (144), wherein a through hole (142) is provided in the bottom wall of the positive current collector (14); a positive electrode foil (15) located in the receiving space (144); wherein the washer (20) comprises a washer part (21) and a spring element portion (22) which are arranged crosswise, the length of the washer part (21) is L1, the length of the spring element portion (22) is L2, L1>L2, wherein either one or both of the spring element portion (22) and the washer part (21) are provided with a raised structure (23), the raised structure (23) passes through the through hole (142) and is attached to the positive electrode foil (15). [2] The button battery (1) according to claim 1, wherein the washer part (21), the spring element portion (22) and the raising structure (23) are integrally formed, and wherein the thickness of the washer (20) is set as t, 0.05≤t≤0.30mm. [3] Button battery (1) according to claim 1 or 2, wherein the raised structure (23) comprises a first flange (231) and a second flange (232), and wherein the first flange (231) and the second flange (232) are respectively arranged at the two ends of the spring element portion (22). [4] Button battery (1) according to claim 3, wherein the height of the first flange (231) or the second flange (232) is set as h1, 2t [5] Button battery (1) according to one of claims 1 to 4, wherein the raised structure (23) comprises at least two raised portions (233) arranged on the washer part (21), and at least two of these raised portions (233) are arranged symmetrically and are located on both sides of the spring element portion (22).​ [6] Button battery (1) according to claim 5, wherein the height h2 of the projections (233) is set such that 1.5t ≤ h2 ≤ 3t. [7] Button battery (1) according to one of claims 1 to 6, wherein an orthogonal projection of the washer (20) onto the positive cover (11) is "+"-shaped, " "-shaped or as a combination of circular and "+"-shaped. [8] Button battery (1) according to one of claims 1 to 7, wherein the washer (20) is provided with a positioning hole (25) which serves for positioning when welding the washer (20) to the positive cover (11), wherein the washer (20) is welded to the positive cover (11) so that a concentricity between the washer (20) and the positive cover (11) is less than or equal to 0.3 mm. [9] Button battery (1) according to claim 8, wherein at least two first welds (210) are present between the washer (20) and the positive cover (11), wherein at least two of these first welds (210) are arranged symmetrically relative to the center of the washer (20). [10] Button battery (1) according to claim 9, wherein the washer (20) comprises a first region (Q1), a second region (Q2a, Q2b) arranged on the washer part (21), and a third region (Q3a, Q3b) arranged on the spring element section (22), wherein the first region (Q1) is symmetrical with respect to the center line of the washer part (21) and the center line of the spring element section (22), wherein the second region (Q2a, Q2b) comprises a first sub-region (Q2a) and a second sub-region (Q2b), which are each arranged on opposite sides of the first region (Q1), and wherein the third region (Q3a, Q3b) comprises a third sub-region (Q3a) and a fourth sub-region (Q3b), which are each arranged on opposite sides of the first region (Q1), wherein the length of the first region (Q1) is d1, d1=0.5·L1 and the width of the first region (Q1) corresponds to the width of the washer part (21); wherein at least two of the first welds (210) are located within the first region (Q1) and / or at least two of the first welds (210) are arranged within the first sub-region (Q2a) and the second sub-region (Q2b); and wherein at least two of the first welds (210) are located outside the third sub-region (Q3a) and the fourth sub-region (Q3b). [11] Button battery (1) according to one of claims 1 to 10, wherein the positive current collector (14) comprises an annular bottom wall (141) to which both ends of the washer part (21) are connected. [12] The button battery (1) according to claim 11, wherein a diameter of the outer circle corresponding to the edge of the washer part (21) is set as D1, and the washer part (21) comprises two washer end portions (214), one of the washer end portions (214) having two washer end points (2143), and the angle between the connecting lines of these two washer end points (2143) with the center of the washer (20) is 2·θ2, wherein a diameter of the through hole (142) of the positive current collector (14) is set as D3, a diameter of the annular bottom wall (141) of the positive current collector (14) is set as D4, and a thickness of the positive current collector (14) is set as t3, wherein a length L1 of the washer part satisfies the following condition: L1 = D1·cosθ2, and 1.02 D3 cosθ2 ≤ L1 ≤ 0.98 (D4 - 2 t3) cosθ2. [13] Button battery (1) according to claim 12, wherein the washer part (21) has two opposite washer side edges (215), and the washer end portions (214) are arranged to project from the washer side edges (215); or the washer end portions (214) are arranged to be flush with the washer side edges (215). [14] The button battery (1) according to claim 12 or 13, wherein a width of the washer part (21) is set as w3, a diameter of the through hole (142) of the positive current collector (14) is set as D3, and the spring element portion (22) has two spring element end portions (222), one of the spring element end portions (222) includes two spring element end points (2223), and the angle between the connecting lines of these two spring element end points (2223) with the center of the washer (20) is 2·θ3, wherein a length L2 of the spring element portion satisfies the following condition: 1.5·w3 ≤ L2 ≤ 0.98·D3·cosθ3. [15] Button battery (1) according to claim 1, wherein the washer part (21) and the spring element portion (22) are formed separately, and wherein the raised structure (23) is formed integrally with the washer part (21) or the spring element portion (22). [16] Button battery (1) according to claim 15, wherein the washer part (21) comprises a washer base body (211) and a washer elevation (212) arranged protruding relative to the washer base body (211), wherein the washer elevation (212) together with the washer base body (211) defines a washer receiving space (213) which is adapted to receive a part of the spring element section (22); Or, the spring element section (22) comprises a spring element base body (221) and a spring element elevation (223) arranged so as to protrude relative to the spring element base body (221), wherein the spring element elevation (223) together with the spring element base body (221) defines a spring element receiving space (224) which is designed to receive a part of the washer part (21). [17] The button battery (1) according to claim 16, wherein a thickness of the spring element portion (22) is set as t1, a height of the washer protrusion (212) is set as H1, and wherein the height H1 of the washer protrusion (212) is not less than the thickness t1 of the spring element portion (22); and / or, wherein a width of the spring element portion (22) is set as w1, a width of the washer protrusion (212) is set as w2, and the ratio of the width w2 of the washer protrusion (212) to the width w1 of the spring element portion (22) is (1.05~1.3):1; Or, wherein a thickness of the washer part (21) is set as t2, a height of the spring element elevation (223) is not smaller than the thickness t2 of the washer part (21); and / or, wherein a width of the washer part (21) is set as w3, and the ratio of the width of the spring element elevation (223) to the width w3 of the washer part (21) is (1.05~1.3):

1. [18] Button battery (1) according to claim 17, wherein the thickness t1 of the spring element portion (22) satisfies the following: 0.05 mm ≤ t1 ≤ 0.30 mm; and / or the thickness t2 of the washer part (21) satisfies the following: 0.05 mm ≤ t2 ≤ 0.30 mm; and / or the thickness t1 of the spring element portion (22) is set to the same thickness t2 of the washer portion (21). [19] Button battery (1) according to claim 17 or 18, wherein the spring element portion (22) is welded to the washer part (21), and the number of second welding points (241) between the spring element portion (22) and the washer part (21) is an even number. [20] Button battery according to claim 19, wherein the spring element portion (22) is welded to the washer part (21) in a circular welding area (Q5), the diameter of the circular welding area (Q5) is smaller than the width w1 of the spring element portion (22), and the diameter of the circular welding area (Q5) is smaller than the width w3 of the washer part (21). [21] Button battery (1) according to one of claims 17 to 20, wherein the raised structure (23) comprises a first flange (231) and a second flange (232) arranged on the spring element portion (22), the first flange (231) being arranged at one end of the spring element portion (22), the second flange (232) being arranged at the other end of the spring element portion (22), and the first flange (231) and the second flange (232) protruding through the through-hole (142) and being embedded in the positive electrode foil (15). [22] Button battery (1) according to claim 21, wherein the height h1 of the first flange (231) or the second flange (232) is set such that 2t1 < h1 < 10t1; and / or the extension of the outer sectional surface of the first flange (231) or the second flange (232) forms an angle θ1 with the plane in which the spring element base body (221) is located, wherein θ1 is in a range from 90° to 150°. [23] Button battery (1) according to claim 21 or 22, wherein the raised structure (23) further comprises the washer raised portion (212), the washer raised portion (212) passing through the through-hole (142) and being embedded in the positive electrode foil (15). [24] Button battery (1) according to one of claims 15 to 23, wherein an orthogonal projection of the washer (20) onto the positive cover (11) is "+"-shaped, wherein an orthogonal projection of the spring element portion (22) and the washer part (21) onto the positive cover (11) is linear. [25] Button battery (1) according to claim 24, wherein the spring element portion (22) and the washer part (21) are made of the same stainless steel material. [26] Button battery (1) according to one of claims 19 to 25, wherein the washer (20) is welded to the positive cover (11), and wherein the washer (20) and the spring element end points (11) are each formed centrally symmetrically, so that the concentricity between the washer (20) and the positive cover (11) is not greater than 0.3 mm. [27] Button battery (1) according to claim 26, wherein at least two third welding points (242) are provided between the washer (20) and the positive cover (11), and at least two of these third welding points (242) are arranged symmetrically relative to the center of the washer (20). [28] Button battery (1) according to claim 27, wherein the washer (20) comprises a first region (Q1) formed by welding the washer part (21) to the spring element section (22), a second region (Q2a, Q2b) arranged on the washer part (21), and a third region (Q3a, Q3b) arranged on the spring element section (22), wherein the second region (Q2a, Q2b) comprises a first sub-region (Q2a) and a second sub-region (Q2b), which are each arranged on opposite first sides of the first region (Q1), and the third region (Q3a, Q3b) comprises a third sub-region (Q3a) and a fourth sub-region (Q3b), which are each arranged on opposite second sides of the first region (Q1); wherein at least two of the third welds (242) are located within the first sub-region (Q2a) and the second sub-region (Q2b); and wherein at least two of the third welds (242) are located outside the third sub-region (Q3a) and the fourth sub-region (Q3b). [29] Button battery (1) according to claim 28, wherein the distance d1 between the at least two third welding points (242) is set such that 0.3-L1+0.7:w1 ≤ d1 ≤ 0.9·L1+0.1·w1. [30] Button battery (1) according to one of claims 15 to 29, wherein the positive current collector (14) has an annular bottom wall (141) to which both ends of the washer part (21) are attached. [31] Button battery (1) according to claim 30, wherein the diameter of the outer circle belonging to the washer part (21) is defined as D1, wherein the washer part (21) has a first end piece (2141) and a second end piece (2142), wherein the first end piece (2141) comprises two washer end points (2143), and the angle between the connecting lines of these two washer end points (2143) and the center of the washer part (21) is defined as 2θ2, wherein the diameter of the through hole (142) of the positive current collector (14) is defined as D3, the diameter of the annular bottom wall (141) of the positive current collector (14) is defined as D4, and the thickness of the positive current collector (14) is defined as t3, wherein the length L1 of the washer part satisfies the relationship L1 = D1 cosθ2 and 1.02 D3 cosθ2 ≤ L1 ≤ 0.98 (D4 - 2 t3) cosθ2 applies. [32] Button battery (1) according to claim 31, wherein the spring element section (22) comprises a first spring element end section (2221) and a second spring element end section (2222), wherein the first spring element end section has two spring element end points (2223), and the angle between the connecting line of the two spring element end points (2223) and the center of the spring element section (22) is 203, and the length L2 of the spring element section (22) satisfies the following condition: 1.5·w3 ≤L2 ≤0.98·D3·cosθ3.

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