Secondary battery, battery pack, and electronic device

Abstract

To provide a secondary battery which suppresses generation of a relatively large compression force to an insulation member in a process that a terminal is riveted, a battery pack, and an electronic device.SOLUTION: A secondary battery includes a casing, a terminal, and an insulation member. The casing includes an end wall, and the end wall is provided with a terminal hole. The terminal includes a columnar part which penetrates the terminal hole, and a caulking part which is folded toward an outer edge of the end wall with respect to the columnar part. A connection portion between the caulking part and the columnar part is a transition part, and when folding the caulking part toward the outer edge of the end wall, a material deformation is generated in the transition part. The insulation member insulates the terminal from the end wall, and includes a pressure receiving part which is in contact with the terminal. The pressure receiving part receives a compression stress in bending the transition part. A stress mitigation structure is provided in at least one of the transition part and the pressure receiving part, and the stress mitigation structure mitigates a pressure from the transition part to the pressure receiving part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of batteries, and more particularly to secondary batteries, battery packs and electronic devices. [Background technology]

[0002] Currently, cylindrical batteries have mature production processes, high yield rates, low processing costs, and good safety and heat dissipation performance, making them widely used in various industries.

[0003] The terminals of existing cylindrical batteries are usually fixed to the end walls of the casings by riveting, and an insulating material is sandwiched between the terminals and the end walls. During the terminal assembly process, the bending area of ​​the terminal generates a relatively large compressive force on the insulating material, which may cause compressive fracture of the insulating material and even lead to a short circuit between the terminals and the end walls. Summary of the Invention [Problem to be solved by the invention]

[0004] In consideration of the above-mentioned drawbacks of the prior art, the present invention provides a secondary battery, a battery pack and an electronic device, which overcome the problem that a relatively large compressive force is generated on an insulating member during the riveting process of a terminal. [Means for solving the problem]

[0005] To achieve the above and other related objects, the present invention provides a secondary battery. The secondary battery includes a casing, a terminal, and an insulating member. The casing includes an end wall, and the end wall has a terminal hole. The terminal includes a columnar portion that passes through the terminal hole and a crimped portion that is folded back from the columnar portion toward the outer edge of the end wall. Here, the connection between the crimped portion and the columnar portion is a transition portion, and material deformation occurs in the transition portion when the crimped portion is folded back toward the outer edge of the end wall. The insulating member insulates the terminal from the end wall and includes a pressure-receiving portion that contacts the terminal, and the pressure-receiving portion is subjected to compressive stress when the transition portion is bent. Here, at least one of the transition portion and the pressure-receiving portion is provided with a stress relief structure, and the stress relief structure relieves pressure from the transition portion to the pressure-receiving portion.

[0006] In one example of the secondary battery of the present invention, the crimped portion is located inside the casing along the height direction of the secondary battery.

[0007] In one example of the secondary battery of the present invention, the stress relaxation structure includes a first stress relaxation structure located in the transition portion, and the first stress relaxation structure is disposed so as to surround the columnar portion continuously or intermittently.

[0008] In one example of the secondary battery of the present invention, the first stress relaxation structure includes a first groove, and the wall thickness of the first groove portion is 0.3 mm to 1 mm.

[0009] In one example of the secondary battery of the present invention, the stress relaxation structure includes a gap.

[0010] In one example of the secondary battery of the present invention, the transition portion has an uneven surface.

[0011] In one example of the secondary battery of the present invention, the stress relaxation structure includes a second stress relaxation structure located in the pressure-receiving portion, the pressure-receiving portion including a first portion disposed in the terminal hole and a second portion disposed between the crimped portion and the end wall, the first portion and the second portion being integrally molded.

[0012] In one example of the secondary battery of the present invention, the second stress relaxation structure is located at the connection between the first part and the second part, and the second stress relaxation structure includes a second groove, which is arranged to surround the first part continuously or intermittently.

[0013] In one example of the secondary battery of the present invention, the second stress relaxation structure is located in the second portion, and the second stress relaxation structure includes a third groove, which is arranged to continuously or intermittently surround the first portion.

[0014] In one example of the secondary battery of the present invention, the second stress relaxation structure is located in the first portion, and the second stress relaxation structure includes a fourth groove, which is arranged to continuously or intermittently surround the first portion.

[0015] In one example of the secondary battery of the present invention, the stress relaxation structure includes a third stress relaxation structure installed on the edge of the terminal hole facing the crimped portion, and the third stress relaxation structure is a chamfer, and the shape of the chamfer is one or more of a wedge shape and an arc shape.

[0016] In one example of the secondary battery of the present invention, the secondary battery is a cylindrical battery.

[0017] In one example of the secondary battery of the present invention, the cylindrical battery includes a casing, one end of which is open and the other end of which is sealed, and a terminal hole is provided at the sealed end of the casing.

[0018] In one example of the secondary battery of the present invention, the casing is a steel case.

[0019] The present invention further provides a battery pack including any of the above secondary batteries.

[0020] The present invention further provides an electronic device including the battery pack described above. [Effects of the Invention]

[0021] The secondary battery of the present invention has a stress relief structure on at least one of the edge of the terminal hole facing the crimped portion, the position where the crimped portion is bent relative to the columnar portion, and the position where the insulating member faces the crimped portion. This reduces the compressive force on the insulating member when the terminal is riveted, allowing the crimped portion to avoid stress concentration positions in the insulating member, thereby improving the problem of insulating member breakage. At the same time, the present invention also improves the problem of warping at the end of the insulating member away from the terminal, further improving the assembly quality of secondary batteries. [Brief explanation of the drawings]

[0022] In order to more clearly describe the embodiments of the present invention or the means in the prior art, the following will briefly describe the drawings required in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other embodiments based on these drawings without creative efforts.

[0023] [Figure 1] 1 is a structural schematic diagram of an example of a secondary battery of the present invention. [Figure 2] 1 is a structural schematic diagram of an electrode assembly of an example of a secondary battery of the present invention. [Figure 3] FIG. 2 is a local enlarged view of part A in FIG. [Figure 4] FIG. 4 is a local enlarged view of part B in FIG. 3. [Figure 5] FIG. 2 is a schematic structural view of Example 1 of the secondary battery of the present invention before the terminals are riveted. [Figure 6] FIG. 2 is a schematic structural view of Example 2 of the secondary battery of the present invention before the terminals are riveted. [Figure 7] FIG. 10 is a schematic structural view of Example 3 of the secondary battery of the present invention before the terminals are riveted. [Figure 8] FIG. 10 is a schematic structural view of Example 4 of the secondary battery of the present invention before the terminals are riveted. [Figure 9] FIG. 2 is a schematic structural view of an example of a secondary battery of the present invention after terminals have been riveted. [Figure 10]FIG. 10 is a structural schematic diagram of another example of a secondary battery of the present invention after terminals are riveted. [Figure 11] FIG. 10 is a structural schematic diagram of yet another example of a secondary battery of the present invention after terminals are riveted. [Figure 12] 1 is a structural schematic diagram of an insulating member in an example of a secondary battery of the present invention. [Figure 13] FIG. 13 is a local enlarged view of part C in FIG. 12. [Figure 14] 4 is a structural schematic diagram of an insulating member in another example of a secondary battery of the present invention. FIG. [Figure 15] FIG. 15 is a local enlarged view of part D in FIG. 14. [Figure 16] FIG. 10 is a structural schematic diagram of an insulating member in yet another example of a secondary battery of the present invention. [Figure 17] FIG. 17 is a local enlarged view of part E in FIG. 16. [Figure 18] 1 is a schematic diagram of an example of a battery pack of the present invention. [Figure 19] 1 is a schematic diagram of an example of an electronic device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed herein. The present invention can be implemented or applied in further different specific embodiments, and the details of each item in this specification can be modified or substituted in various ways based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following examples and features in the examples can be combined with each other, under compatible circumstances. It should also be understood that the terms used in the examples of the present invention are intended to describe specific embodiments and are not intended to limit the scope of protection of the present invention. In the following examples, test methods for which specific conditions are not specified are usually performed according to conventional conditions or conditions recommended by each manufacturer.

[0025] When the examples indicate a range of values, it should be understood that the two endpoints of each range and any value between those endpoints can be selected unless otherwise specified in the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention are based on the understanding of the prior art by those skilled in the art and the description of the present invention, and the present invention can also be realized using any methods, devices, and materials in the prior art that are similar or equivalent to the methods, devices, and materials in the examples of the present invention.

[0026] It should be noted that the terms "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are used for the convenience of clarifying the description and do not limit the scope in which the present invention can be implemented; any change or adjustment of their relative relationships is considered to be within the scope in which the present invention can be implemented, provided that there is no substantial change in the technical content.

[0027] In the present invention, the secondary battery includes an electrode assembly, which is a component where an electrochemical reaction occurs in the secondary battery, and may include one or more electrode assemblies.

[0028] The secondary battery further includes a casing, a cover plate, and a terminal. The casing includes an end wall and a side wall surrounding the end wall. One end of the side wall has an opening. The electrode assembly can be assembled inside the casing through the opening. The cover plate is used to cover the opening of the casing to achieve sealing. The terminal passes through the end wall and is electrically connected to the electrode assembly to conduct power generated by the electrode assembly.

[0029] To reduce the risk of short circuits, the terminal and the end wall must be insulated and separated, and this is usually achieved by sandwiching an insulating member between the terminal and the end wall, with the insulating member being at least partially positioned between the terminal and the end wall to insulate them from each other.

[0030] In the related art, when assembling a terminal and an end wall, the terminal is usually first inserted into a terminal hole on the end wall from one side so that the outer end of the terminal protrudes from the other side of the end wall, and then the outer end of the terminal is compressed to form a crimp portion and fix the terminal to the end wall.

[0031] During the folding process of the crimped portion, the inside of the crimped portion is subjected to compressive stress and the outside to tensile stress, causing the outer material to stretch and the inner material to flow under the compressive stress, resulting in material deformation and the formation of a protrusion at the bending point where the crimped portion and the insulating material come into contact. This protrusion comes into contact with the stress concentration area of ​​the insulating material, and the combined action of the compressive force of the crimped portion and the protrusion can cause the insulating material to break, resulting in the insulating function of the insulating material being lost and even leading to a short circuit between the terminal and the end wall. In addition, the insulating material can also warp up at the end away from the terminal under the compressive force, further affecting the assembly quality of the battery.

[0032] In consideration of this, the present invention provides a means to solve the problem by providing a stress relief structure at least in one of the edge of the terminal hole facing the crimped portion, the position where the crimped portion bends relative to the columnar portion, and the position where the insulating member and the crimped portion face each other. This reduces the compressive force from the terminal to the insulating member during riveting, and allows the crimped portion to avoid stress concentration positions in the insulating member, thereby alleviating the problem of insulating member breakage. At the same time, the present invention also alleviates the problem of warping at the end of the insulating member away from the terminal, further improving the assembly quality of secondary batteries.

[0033] Please refer to Figures 1 to 19. The present invention provides a secondary battery 100, a battery pack 10 and an electronic device 1, where the secondary battery 100 includes a casing 110, an electrode assembly 120, a terminal 140 and a cover plate .

[0034] Please refer to FIG. 1. FIG. 1 is a structural schematic diagram of an example of a secondary battery of the present invention. The casing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. The connection between the end wall 111 and the side wall 112 can be realized in various ways as long as a stable sealing and electrical connection can be formed. For example, it can be formed by integral press molding, integral casting, or split welding. The surrounding shape of the side wall 112 is not limited and can be cylindrical or prismatic, or can be formed along any other closed loop contour that matches the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 cylindrically surrounds the outer edge of the end wall 111. A circular opening 113 is formed at the end of the side wall 112 away from the end wall 111. A storage space is formed within the casing 110, surrounded by the end wall 111 and the side wall 112, and is used to accommodate the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter size of the casing 110 may be determined based on the specific dimensions of the electrode assembly 120, and may be, for example, 18 mm, 21 mm, 46 mm, etc. The casing 110 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. To prevent the casing 110 from rusting during long-term use, the surface of the casing 110 may be plated with an anti-rust material such as metallic nickel.

[0035] Please refer to FIGS. 1 and 2. FIG. 2 is a structural schematic diagram of an electrode assembly of an example of a secondary battery of the present invention. The electrode assembly 120 is housed in the casing 110 and is a component where an electrochemical reaction occurs in the secondary battery 100. One or more electrode assemblies 120 may be included in the casing 110. The electrode assembly 120 includes an electrode plate and a separator 122, which are wound together to form a wound structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive electrode plate 121, a separator 122, and a negative electrode plate 123 wound in the axial direction of the casing 110. The positive electrode plate 121 includes a positive electrode current collector 1211 and a positive electrode active material layer coated on the positive electrode current collector 1211. A first coated region 1212 coated with the positive electrode active material layer and a first uncoated region 1213 not coated with the positive electrode active material layer are formed on the positive electrode current collector 1211. The first coated region 1212 and the first non-coated region 1213 are arranged along the axial direction of the casing 110, and the first non-coated region 1213 extends to the outside of the separator 122 at one end in the height direction of the secondary battery 100 and is bent toward the axis of the casing 110 to form a stacked positive electrode tab 125. The negative electrode plate 123 includes a negative electrode current collector 1231 and a negative electrode active material layer applied on the negative electrode current collector 1231, and a second coated region 1232 coated with the negative electrode active material layer and a second non-coated region 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231. The second coated region 1232 and the second uncoated region 1233 are arranged along the axial direction of the casing 110, and the second uncoated region 1233 extends to the outside of the separator 122 at the other end of the height direction of the secondary battery 100 and is bent toward the axis of the casing 110 to form a stacked negative electrode tab 124. The separator 122 is installed between the positive electrode plate 121 and the negative electrode plate 123 to insulate the positive electrode active material layer from the negative electrode active material layer. Taking the lithium ion secondary battery 100 as an example, the positive electrode current collector 1211 is made of aluminum, and the positive electrode active material layer includes a positive electrode active material, such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide.The negative electrode current collector 1231 is made of copper, and the negative electrode active material layer contains a negative electrode active material, such as carbon or silicon. The separator 122 is made of a base material such as PP (polypropylene) or PE (polyethylene). To protect and insulate the cell, the outside of the cell may be coated with an insulating film, which may be made of PP, PE, PET, PVC, or other high molecular weight polymer materials.

[0036] See Figures 1 and 2. Furthermore, in the present invention, when the positive electrode tab 125 faces the end wall 111 or the opening 113, the negative electrode tab 124 faces the other end of the casing 110. In this embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected to the terminal 140, causing the terminal 140 to be positively charged, and the negative electrode tab 124 faces the opening 113, causing the casing 110 to be electrically connected to the negative electrode tab 124, causing the casing 110 to be negatively charged. However, in other embodiments, the negative electrode tab 124 may be connected to the terminal 140, and the positive electrode tab 125 may be connected to the casing 110.

[0037] See FIG. 1. The cover plate 130 is hermetically mounted in the opening 113. The outer edge shape of the cover plate 130 corresponds to the shape of the opening 113 and connects with the side wall 112 to seal the opening 113. The mounting method of the cover plate 130 may include, but is not limited to, mechanical sealing or welding sealing. In this embodiment, the cover plate 130 seals the opening 113 using a mechanical sealing method.

[0038] Please refer to Figures 1 to 4. Figure 3 is a local enlarged view of part A in Figure 1, and Figure 4 is a local enlarged view of part B in Figure 3. A terminal hole 1111 is provided in the end wall 111, and the terminal 140 is inserted into the terminal hole 1111 and insulated from the end wall 111. One end of the terminal 140 facing the electrode assembly 120 penetrates the end wall 111 and is electrically connected to the positive electrode tab 125 directly or via an indirect intermediate connection. The structural form of the terminal 140 may be any suitable form that can penetrate the end wall 111 and electrically connect to the positive electrode tab 125 of the electrode assembly 120. For example, the cross section may be circular, rectangular, prism-shaped, or a contoured shape that can achieve stable electrical conductivity, and the terminal hole 1111 corresponds to the shape of the terminal 140. In this embodiment, the cross section of the terminal 140 is circular.

[0039] The terminal 140 includes a post-shaped portion 142 that passes through the terminal hole 1111 and a crimping portion 141 that is bent toward the outer edge of the end wall 111 relative to the post-shaped portion 142. The cross section of the post-shaped portion 142 may be circular, rectangular, prismatic, or any other irregular contour that can achieve stable electrical conductivity. For better sealing and fitting, the post-shaped portion 142 preferably matches the shape of the terminal hole 1111. That is, the terminal hole 1111 corresponds to the shape of the post-shaped portion 142. In this embodiment, the post-shaped portion 142 has a circular cross section, and the circular design facilitates processing, assembly, and sealing. The portion where the crimping portion 141 and the post-shaped portion 142 connect is a transition portion 145. During the riveting process of the terminal 140, when the crimping portion 141 is bent back toward the outer edge of the end wall 111, the inside of the transition portion 145 is subjected to compressive stress, and the outside of the transition portion 145 is subjected to tensile stress. The side of the transition portion 145 facing the outer edge of the end wall 111 is the inner side, and the other side of the transition portion 145 facing the inner side is the outer side. Because the material located on the outer side is stretched and the material located on the inner side flows under the action of compressive stress, material deformation occurs in the transition portion 145 when the crimping portion 141 is folded back onto the outer edge of the end wall 111. The terminal 140 is made of a conductive metal material, and the material of the terminal 140 may be copper, nickel, aluminum, or the like. In this embodiment, the material of the terminal 140 is aluminum, and selecting aluminum makes it easy to perform the crimping process.

[0040] See Figures 3 and 4. The insulating member 150 is used to isolate the terminal 140 from the end wall 111. At least a portion of the insulating member 150 is disposed between the crimped portion 141 and the end wall 111, and between the side wall of the terminal hole 1111 and the columnar portion 142, thereby insulating and isolating the end wall 111 from the terminal 140. The crimped portion 141 is bent away from the axis of the terminal 140 and connected to the columnar portion 142. This acts as a limiter, restricting the separation between the terminal 140 and the end wall 111 and compressing and fixing the insulating member 150. Specifically, the insulating member 150 includes a first insulator 152 and a second insulator 153, which are integrally molded. The first insulator 152 is disposed between the side wall of the terminal hole 1111 and the columnar portion 142, and is used to isolate the side wall of the terminal hole 1111 from the columnar portion 142. The second insulator 153 is pressed against the end wall 111 by the crimping portion 141 and is used to isolate the crimping portion 141 from the end wall 111 on the one hand, and to isolate the electrode assembly 120 from the end wall 111 on the other hand. The first insulator 152 and the second insulator 153 are installed vertically. The insulating member 150 includes a pressure-receiving portion 151 that contacts the terminal 140. Because the pressure-receiving portion 151 is simultaneously compressed by the post-shaped portion 142 and the crimping portion 141, the pressure-receiving portion 151 is subjected to compressive stress when the transition portion 145 is bent.

[0041] See Figures 3 and 4. Preferably, in another embodiment, the insulating member 150 further includes a third insulator 154 disposed between the restriction portion 143 and the end wall 111. The third insulator 154 and the first insulator 152 may be integrally molded or may be disposed separately and independently, and this is not limited thereto. In this embodiment, the third insulator 154 and the first insulator 152 are disposed separately and independently. The material of the insulating member 150 may be, but is not limited to, EPDM (tertiary ethylene propylene rubber), fluorosilicone rubber, or fluororubber.

[0042] Furthermore, a stress relief structure 160 is provided on at least one of the transition portion 145 and the pressure-receiving portion 151, and the stress relief structure 160 is used to relieve pressure on the insulating member 150 when the terminal 140 is riveted. That is, the stress relief structure 160 may be provided only on the transition portion 145 or only on the pressure-receiving portion 151. Whether the stress relief structure 160 is provided at either the transition portion 145 or the pressure-receiving portion 151, it can still reduce the compressive force that the crimping portion 141 applies to the insulating member 150. Of course, in some other embodiments, the stress relief structure 160 may be provided at both the transition portion 145 and the pressure-receiving portion 151. The location of the stress relief structure 160 on the transition portion 145 and the pressure-receiving portion 151 is not limited, and the stress relief structure 160 may be provided at any location. The stress relief structure 160 may have various forms, such as a groove or a chamfer. The cross-sectional shape of the groove may be an arc, a rectangle, a triangle, or any other irregular shape, and the angle and shape of the chamfer may also vary, and are not limited here as long as the crimped portion 141 can have the effect of alleviating the compressive force applied to the insulating member 150.

[0043] See Figures 1, 3, and 4. In one example of the secondary battery 100 of the present invention, the terminal 140 further includes a limiting portion 143, which is connected to the other end of the columnar portion 142, away from the crimped portion 141, and protrudes from the side wall 112 of the columnar portion 142. The limiting portion 143 is provided to restrict the separation between the terminal 140 and the end wall 111, and to provide electrical connection with the electrode assembly 120 or the outside, thereby discharging the power generated by the electrode assembly 120. The cross section of the limiting portion 143 may be circular, square, prismatic, or any other irregular contour that can achieve stable conductivity. In this embodiment, the cross section of the limiting portion 143 is also circular.

[0044] See Figures 1, 3, and 4. The crimping portion 141 is located inside or outside the casing 110 along the height direction of the secondary battery 100. Specifically, the crimping portion 141 and the limiting portion 143 are located on both sides of the end wall 111, respectively, and rivet the terminal 140 and the end wall 111 to secure the terminal 140 to the end wall 111. The crimping portion 141 is located on the side of the end wall 111 closest to the electrode assembly 120 and can be electrically connected to the electrode assembly 120. In this case, the limiting portion 143 is located on the opposite side of the end wall 111 and can be electrically connected to an external power-using device to deliver power generated by the electrode assembly 120. In another embodiment, the limiting portion 143 is located on the side of the end wall 111 closest to the electrode assembly 120 and can be electrically connected to the electrode assembly 120. In this case, the crimping portion 141 is located on the opposite side of the end wall 111 and can be electrically connected to an external power-using device to deliver power generated by the electrode assembly 120.

[0045] In one example of the secondary battery 100 of the present invention, the crimping portion 141 is located inside the casing 110, and the limiting portion 143 is located outside the casing 110. Because the crimping portion 141 is formed by riveting later, its shape is uncontrollable due to external influences, but the limiting portion 143 is processed in advance and has a regular, controllable shape. Therefore, by placing the limiting portion 143 on the outside of the casing 110, both aesthetic appearance and the safety of the electrical connection with an external power-using device are ensured.

[0046] See Figures 3 to 11. In one example of the secondary battery 100 of the present invention, the stress relief structure 160 includes a first stress relief structure 161 located at the transition portion 145. The first stress relief structure 161 is installed to surround the columnar portion 142 continuously or intermittently, and the first stress relief structure 161 is located inside the transition portion 145. In the intermittent surrounding arrangement, the number and length of interruptions are not limited and may be freely designed according to actual circumstances. The intermittent surrounding first stress relief structure 161 reduces the compressive force on the insulating member 150 when the terminal 140 is riveted, while also taking into consideration the crimping strength of the terminal 140. A continuous surrounding arrangement better relieves the compressive force applied by the terminal 140 to the insulating member 150. If the wall thickness of this portion is within the range of 0.3 mm to 1 mm, the crimping portion 141 of the terminal 140 can also have high strength. The first stress relaxation structure 161 in this embodiment adopts a structure that continuously surrounds the columnar portion 142 .

[0047] See Figures 5 to 8. The first stress relief structure 161 at this position must be preset on the outer wall of the terminal body 144 before the terminal body 144 is bent. When the terminal body 144 is bent, it is bent along the location of this first stress relief structure 161. The portion of the terminal body 144 that is bent away from the axis of the terminal 140 forms the crimped portion 141, and the unbent portion of the terminal body 144 becomes the aforementioned columnar portion 142. The presence of this first stress relief structure 161, on the one hand, reduces the amount of material that the terminal body 144 deforms, and on the other hand, the crimped portion 141 provides an accommodation space for the flow of material that occurs inside the transition portion 145, further reducing the difficulty of bending.

[0048] For ease of understanding, the following description will focus on the structure of the terminal 140 before riveting. The first stress relief structure 161 is a groove formed on the outer wall of the terminal body 144. The size and shape of the groove are not limited and may be rectangular, arc-shaped, elliptical, triangular, waist-shaped, or other irregular shapes. Referring to FIGS. 5 to 8, several examples of the first stress relief structure 161 formed on the outer wall of the terminal body 144 are shown. Example 1, as shown in FIG. 5, illustrates the structure of the terminal of Example 1 of the secondary battery of the present invention before riveting, and the cross-sectional shape of the first stress relief structure 161 is rectangular. Example 2, as shown in FIG. 6, illustrates the structure of Example 2 of the secondary battery of the present invention before riveting, and the cross-sectional shape of the first stress relief structure 161 is waist-shaped. Example 3, as shown in FIG. 7, illustrates the structure of Example 3 of the secondary battery of the present invention before riveting, and the cross-sectional shape of the first stress relief structure 161 is elliptical. Example 4, as shown in FIG. 8, is a view showing the structure of Example 4 of the secondary battery of the present invention before the terminals are riveted, and the cross-sectional shape of the first stress relaxation structure 161 is circular.

[0049] Due to the different shapes and different dimensions of the first stress relief structure 161 at the corresponding positions, as well as the uncontrollable factor of material deformation, the first stress relief structure 161 will have different shapes after the riveting is completed. This shape is not limited. Three general examples are shown below with reference to Figures 9 to 11.

[0050] FIG. 9 shows an example of a secondary battery 100 according to the present invention after the terminals are riveted. The first stress relaxation structure 161 includes a first groove 1611, and the shape of the first groove 1611 is not limited. Due to the uncertainty of material deformation, the first groove 1611 is often an irregular groove. Furthermore, the first groove 1611 may be disposed so as to surround the columnar portion 142 intermittently or continuously, and this is not limited here. The wall thickness of the first groove 1611 is 0.3 mm to 1 mm, and the wall thickness of the first groove 1611 is as shown by h in FIG. 9. The value of h may be, for example, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. A wall thickness within this dimension range can ensure the crimping strength of the crimped portion 141.

[0051] In another example of a secondary battery 100 according to the present invention, as shown in FIG. 10, which is a diagram illustrating the structure of another example of a secondary battery according to the present invention after the terminals have been riveted. The first stress relaxation structure 161 includes a gap 1612, which is located in the transition portion 145. When the amount of material flow caused by material deformation is approximately equal to the predetermined space reserved in the first stress relaxation structure 161, the groove of the first stress relaxation structure 161 becomes full, and after riveting is completed, a gap 1612 is formed between the columnar portion 142 and the crimped portion 141.

[0052] In yet another example of a secondary battery 100 according to the present invention, as shown in FIG. 11, this figure illustrates the structure of the secondary battery 100 after the terminals are riveted. The transition portion 145 has an uneven surface. According to prior knowledge, the inside of the transition portion 145 is subjected to compressive stress, while the outside is subjected to tensile stress. The material located on the outside is stretched, while the material located on the inside flows due to the compressive stress. Therefore, at the bending point where the crimped portion 141 and the insulating member 150 contact, i.e., the inside of the transition portion 145, material deformation occurs, forming a protruding, smooth transition surface. When the accumulation amount of the material flow caused by the material deformation is approximately equal to the space reserved in the predetermined first stress relaxation structure 161, the deformed material fills the groove of the first stress relaxation structure 161, the protruding, smooth transition surface disappears, and the crimped portion 141 and the columnar portion 142 are bonded together. In this case, the transition portion 145 has an uneven surface, and an edge 1613 is formed at the connection between the crimping portion 141 and the columnar portion 142, which differs from the irregular, protruding, smooth transition surface formed in the prior art. Compared to the protruding, smooth transition surface of the prior art, the edge 1613 increases the distance from the transition portion 145 to the pressure-receiving portion 151, i.e., reduces the amount of compression of the insulating member 150 by the crimping portion 141. This arrangement reduces the compressive force on the insulating member 150 when the terminal 140 is riveted.

[0053] See Figures 3 and 4. During the riveting process of the terminal 140, the insulating member 150 is subjected to double compression by the crimped portion 141 and the end wall 111. To mitigate the risk of the insulating member 150 being broken or warped due to deformation caused by the compression, in one example of the secondary battery 100 of the present invention, the stress relief structure 160 includes a second stress relief structure 162 positioned on the pressure-receiving portion 151. The pressure-receiving portion 151 includes a first portion 1511 disposed within the terminal hole 1111 and a second portion 1512 disposed between the crimped portion 141 and the end wall 111, thereby achieving insulation between the terminal 140 and the end wall 111. It should be noted that, when projected along the axial direction of the secondary battery 100, the overlapping portion of the second insulator 153 and the crimped portion 141 is the second portion 1512, and the first portion 1511 and the second portion 1512 are integrally molded. The insulating member 150 of this arrangement is relatively easy to process and assemble, has good sealing performance, and the pressure-receiving portion 151 is pressed against the end wall 111 by the columnar portion 142 and the crimped portion 141 at the same time.

[0054] Specifically, the second stress relief structure 162 may be located on the side of the pressure-receiving portion 151 closer to the terminal 140 or on the side closer to the end wall 111 of the pressure-receiving portion 151, and this is not a limitation. In this embodiment, the second stress relief structure 162 is located on the side closer to the end wall 111 of the pressure-receiving portion 151, and this location provides the insulating member 150 with better strength. Meanwhile, the second stress relief structure 162 may be located on the first portion 1511, at any position on the second portion 1512, or in a combination of these two locations. Below, three examples of the second stress relief structure 162 on the insulating member 150 are shown in combination with Figures 12 to 17.

[0055] See Figures 3 and 4 and Figures 12 and 13. In one example of the secondary battery 100 of the present invention, the second stress relief structure 162 is located at the junction between the first portion 1511 and the second portion 1512, i.e., part of the second stress relief structure 162 is located in the first portion 1511 and the other part is located in the second portion 1512. As shown in Figures 12 and 13, Figure 12 is a structural diagram of an insulating member in one example of the secondary battery of the present invention, and Figure 13 is a local enlarged view of part C in Figure 12. The second groove 1621 is disposed to surround the first portion 1511 continuously or intermittently, i.e., the second stress relief structure 162 is located on the side facing the end wall 111. This arrangement reduces the tendency of the first insulator 152 to curl up toward the end wall 111 during compression, which on the one hand reduces contact with the edge of the terminal hole 1111 and on the other hand alleviates the problem of the first insulator 152 curling up toward the electrode assembly 120 under compressive force. Furthermore, the second stress relief structure 162 includes a second groove 1621. The cross-sectional shape of the second groove 1621 can be various and is not limited to a specific shape. For example, it can be rectangular, arc-shaped, waist-shaped, triangular, oval, any combination of the above shapes, or other irregular shapes. The second groove 1621 can be configured to surround the first portion 1511 continuously or intermittently. In the case of an intermittent configuration, the number and length of interruptions are not limited and can be freely designed according to actual circumstances. The intermittent second groove 1621 reduces the compressive force on the insulating member 150 when the terminal 140 is riveted, while also taking into consideration the structural strength of the insulating member 150. A continuous configuration can more effectively relieve the compressive force applied by the terminal 140 to the insulating member 150. In this embodiment, the second groove 1621 continuously surrounds the first portion 1511.

[0056] For another example of the secondary battery 100 of the present invention, please refer to FIGS. 3 and 4 and FIGS. 14 and 15. FIG. 14 is a structural diagram of an insulating member in another example of the secondary battery of the present invention, and FIG. 15 is a local enlarged view of portion D in FIG. 14. The second stress relief structure 162 is located in the second portion 1512, facing the end wall 111. The third groove 1622 is disposed so as to surround the first portion 1511 continuously or intermittently. The specific location of the second stress relief structure 162 in the second portion 1512 is not limited. By locating the second stress relief structure 162 on the side facing the end wall 111, the first insulator 152 tends to curl toward the end wall 111 during compression. This can alleviate the problem of the first insulator 152 curling toward the electrode assembly 120 under compressive force. At the same time, the second stress relief structure 162 in this technical solution has the advantage of being easily demolded during processing. Furthermore, the second stress relief structure 162 includes a third groove 1622. The cross-sectional shape of the third groove 1622 can be various and is not limited to a specific shape. For example, it can be rectangular, arc-shaped, waist-shaped, triangular, oval, any combination of the above shapes, or other irregular shapes. The third groove 1622 can be configured to surround the first portion 1511 continuously or intermittently. In the case of an intermittent configuration, the number and length of interruptions are not limited and can be freely designed according to actual circumstances. The intermittent third groove 1622 can reduce the risk of breakage of the insulating member 150 while also considering the structural strength of the insulating member 150. The continuous configuration can better alleviate the problem of the insulating member 150 curling toward the electrode assembly 120 under compressive force. In this embodiment, the third groove 1622 continuously surrounds the first portion 1511.

[0057] For another example of a secondary battery 100 according to the present invention, please refer to FIGS. 16 and 17. FIG. 16 is a structural diagram of an insulating member according to another example of a secondary battery according to the present invention, and FIG. 17 is a partially enlarged view of portion E in FIG. 16. The second stress relief structure 162 is located in the first portion 1511, facing the terminal hole 1111. The fourth groove 1623 surrounds the first portion 1511 continuously or intermittently. Its specific location in the first portion 1511 is not limited. By locating the second stress relief structure 162 on the side facing the end wall 111, the first insulator 152 tends to curl up toward the end wall 111 during compression, which can alleviate the problem of the first insulator 152 curling up toward the electrode assembly 120 under compressive force. Furthermore, the second stress relief structure 162 includes a fourth groove 1623. The cross-sectional shape of the fourth groove 1623 can be varied and is not limited. For example, the fourth groove 1623 may be rectangular, arc-shaped, waist-shaped, triangular, oval, any combination of the above shapes, or other irregular shapes. The fourth groove 1623 may be disposed to surround the first portion 1511 continuously or intermittently. In the case of an intermittent arrangement, the number and length of the intermittent arrangement are not limited and may be freely designed according to actual circumstances. The intermittent arrangement of the fourth groove 1623 reduces the risk of breakage of the insulating member 150 while also taking into consideration the structural strength of the insulating member 150. The continuous arrangement effectively alleviates the problem of the insulating member 150 warping toward the electrode assembly 120 under compressive force. In this embodiment, the fourth groove 1623 continuously surrounds the first portion 1511.

[0058] During the crimping process of the terminal 140, the insulating member 150 is subjected to double compression by the crimping portion 141 and the end wall 111. Therefore, providing a stress relief structure 160 on the end wall 111 can also mitigate the compressive force exerted by the terminal 140 on the insulating member 150. See FIG. 4 for an example of a secondary battery 100 of the present invention. The stress relief structure 160 includes a third stress relief structure 163 provided on the edge of the terminal hole 1111 facing the crimping portion 141. This arrangement prevents contact between the edge of the end wall 111 and the corner of the insulating member 150, where stress concentration occurs, thereby further reducing the risk of fracture of the insulating member 150. The third stress relief structure 163 is a chamfer, and the chamfer shape may be one or more of a wedge shape and an arc shape, or may be a wedge shape, an arc shape, or a combination of a wedge shape and an arc shape. In this embodiment, the chamfer is wedge-shaped.

[0059] Please refer to Figure 1. In one example of the secondary battery 100 of the present invention, the secondary battery 100 is a cylindrical battery.

[0060] Please refer to Figures 1 and 2. In one example of a secondary battery 100 of the present invention, a cylindrical battery includes a casing 110, one end of which is open and the other end of which is sealed. A terminal hole 1111 is provided at the sealed end of the casing 110.

[0061] In one example of the secondary battery 100 of the present invention, the casing 110 of the secondary battery 100 is a steel case.

[0062] Please refer to FIG. 18. FIG. 18 is a schematic diagram of an example of a battery pack of the present invention. The present invention also provides a battery pack 10, which includes any of the secondary batteries 100 described above. In one embodiment of the battery pack 10 of the present invention, the battery pack 10 includes a case body 101, a case cover 102, and a plurality of secondary batteries 100. The plurality of secondary batteries 100 are disposed within the case body 101 and connected to each other in series, parallel, or a combination of series and parallel. The case cover 102 covers and seals the case body 101 to protect the plurality of secondary batteries 100. It should be noted that the battery pack 10 may include, in addition to the secondary battery 100 of the present invention, components such as a thermal management system and a circuit board for the battery pack 10. The battery pack 10 may be a battery module, a battery pack, an energy storage cabinet, or the like. Further details will not be provided here.

[0063] Please refer to FIG. 19. FIG. 19 is a schematic diagram of an example of an electronic device of the present invention. The present invention also provides an electronic device 1, which includes the above-mentioned battery pack 10. A working unit 11 is electrically connected to the battery pack 10 and can receive power. As an example, the electronic device 1 is a vehicle, which may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be, but is not limited to, a pure electric vehicle, a hybrid vehicle, or an extended-range electric vehicle. The working unit 11 is a vehicle body, and the battery pack 10 is installed at the bottom of the body and supplies power to drive the vehicle or to operate electrical components inside the vehicle. However, in other embodiments, the electronic device 1 may be a mobile phone, a portable device, a laptop, a ship, space equipment, an electric toy, an electric tool, or the like. Space equipment includes airplanes, rockets, space shuttles, spacecraft, and the like. The working unit 11 may be a unit component that receives power from the battery pack 10 and performs a corresponding operation, such as a blade rotation unit of an electric fan or a suction unit of a vacuum cleaner. The electric toys include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy boats, electric toy airplanes, etc. The electric tools include metal cutting electric tools, polishing electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, etc. The embodiments of the present invention do not impose any particular restrictions on the electronic device 1.

[0064] The secondary battery of the present invention provides a stress relief structure at at least one of the edge of the terminal hole facing the crimping portion, the position where the crimping portion bends relative to the columnar portion, and the position where the insulating member and the crimping portion face each other. This reduces the compressive force on the insulating member when the terminal is riveted, allowing the crimping portion to avoid stress concentration points on the insulating member, thereby alleviating the problem of insulating member breakage. At the same time, the present invention also alleviates the problem of the insulating member's warping at the end away from the terminal, thereby improving the assembly quality of secondary batteries. Therefore, the present invention effectively overcomes the practical problems of the prior art and has high utility and practical significance. The above-described embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Those skilled in the art may make modifications and variations to the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or substitutions made by those skilled in the art without departing from the disclosed spirit and technical concept of the present invention are intended to be encompassed within the scope of the present invention. [Industrial Applicability]

[0065] The present invention provides a secondary battery, a battery pack, and an electronic device. [Explanation of symbols]

[0066] 1 Electronic equipment 10 Battery Pack 11 Working section 101 Case body 102 Case Cover 100 Secondary battery 110 Casing 111 End Wall 1111 Terminal hole 112 Side wall 113 Aperture 120 Electrode Assembly 121 Positive electrode plate 1211 Positive electrode current collector 1212 First coating area 1213 First uncoated area 122 Separator 123 Negative plate 1231 Negative electrode current collector 1232 Second Coating Area 1233 Second Uncoated Area 124 Negative electrode tab 125 Positive electrode tab 130 Cover Plate 140 terminals 141 Crimping part 142 Columnar part 143 Restricted Section 144 Terminal body 145 Transition part 150 Insulating material 151 Pressure receiving part 1511 First part 1512 Second part 152 First Insulator 153 Second Insulator 154 Third Insulator 160 Stress relief structure 161 First stress relief structure 1611 First groove 1612 gap 1613 Edge 162 Secondary stress relief structure 1621 Second groove 1622 Third groove 1623 Fourth groove 163 Third Stress Relief Structure

Claims

1. a casing (110) including an end wall (111) having a terminal hole (1111) formed therein; a terminal (140) including a columnar portion (142) passing through the terminal hole (1111) and a crimped portion (141) connected to one end of the columnar portion (142) and folded back toward the outer edge of the end wall (111), wherein a connecting portion between the crimped portion (141) and the columnar portion (142) is a transition portion (145), and material deformation occurs in the transition portion (145) when the crimped portion (141) is folded back toward the outer edge of the end wall (111); and an insulating member (150) for insulating the terminal (140) from the end wall (111), the insulating member (150) including a pressure-receiving portion (151) in contact with the terminal (140), the pressure-receiving portion (151) receiving a compressive stress when the transition portion (145) is bent. A secondary battery characterized in that a stress relief structure (160) is provided in at least one of the transition portion (145) and the pressure-receiving portion (151), and the stress relief structure (160) is intended to relieve pressure from the transition portion (145) to the pressure-receiving portion (151).

2. The secondary battery according to claim 1, wherein the crimped portion (141) is located inside the casing (110) along the height direction of the secondary battery.

3. 2. The secondary battery of claim 1, wherein the stress relief structure (160) includes a first stress relief structure (161) located in the transition portion (145), and the first stress relief structure (161) is arranged to surround the columnar portion (142) continuously or intermittently.

4. The secondary battery of claim 3, wherein the first stress relief structure (161) includes a first groove (1611), and the wall thickness at the location of the first groove (1611) is 0.3 mm to 1 mm.

5. The secondary battery of claim 3 , wherein the first stress relief structure (161) includes a gap (1612).

6. The secondary battery of claim 3 , wherein the transition portion (145) has an uneven surface.

7. A secondary battery described in any one of claims 1 to 6, wherein the stress relief structure (160) includes a second stress relief structure (162) located in the pressure-receiving portion (151), the pressure-receiving portion (151) includes a first portion (1511) installed in the terminal hole (1111) and a second portion (1512) installed between the crimping portion (141) and the end wall (111), and the first portion (1511) and the second portion (1512) are integrally molded.

8. The secondary battery of claim 7, wherein the second stress relief structure (162) is located at the connection between the first portion (1511) and the second portion (1512), and the second stress relief structure (162) includes a second groove (1621), which is arranged to surround the first portion (1511) continuously or intermittently.

9. The secondary battery of claim 7, wherein the second stress relief structure (162) is located in the second portion (1512), the second stress relief structure (162) includes a third groove (1622), and the third groove (1622) is arranged to surround the first portion (1511) continuously or intermittently.

10. The secondary battery of claim 7, wherein the second stress relief structure (162) is located in the first portion (1511), the second stress relief structure (162) includes a fourth groove (1623), and the fourth groove (1623) is arranged to surround the first portion (1511) continuously or intermittently.

11. The secondary battery of claim 7, wherein the stress relief structure (160) includes a third stress relief structure (163) installed on the edge of the terminal hole (1111) facing the crimped portion (141), the third stress relief structure (163) being chamfered, and the shape of the chamfer being one or more of a wedge shape and an arc shape.

12. The secondary battery according to claim 1 , wherein the secondary battery is a cylindrical battery.

13. The secondary battery according to claim 12 , wherein the cylindrical battery includes a casing having one open end and the other sealed end, and the terminal hole is provided at the sealed end of the casing.

14. The secondary battery according to claim 13 , wherein the casing is a steel case.

15. A battery pack comprising a secondary battery (100) according to any one of claims 1 to 14.

16. An electronic device comprising a battery pack (10) according to claim 15.

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