Secondary batteries, battery packs, and electronic devices

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 specifically to secondary batteries, battery packs, and electronic devices.

Background Art

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

[0003] The terminals of existing cylindrical batteries are usually fixedly connected to the end wall of the casing by a riveting method, and an insulating member is interposed between the terminal and the end wall. In the process of assembling the terminal, there is a risk that the bending area of the terminal generates a relatively large compressive force on the insulating member, compressing and breaking the insulating member, and further causing a short circuit between the terminal and the end wall.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Considering the drawbacks of the above prior art, the present invention provides a secondary battery, a battery pack, and an electronic device, and improves the problem of generating a relatively large compressive force on the insulating member during the process of riveting the terminal.

Means for Solving the Problems

[0005] To achieve the above-mentioned objectives and other related objectives, the present invention provides a secondary battery. The secondary battery includes a casing, terminals, and an insulating member. The casing includes an end wall, the end wall of which is provided with terminal holes. The terminal includes a columnar portion that penetrates the terminal hole and a crimped portion that is folded back toward the outer edge of the end wall relative to the columnar portion. Here, the connection portion 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 is for insulating the terminal from the end wall and includes a pressure-receiving portion that contacts the terminal, and the pressure-receiving portion receives 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-relieving structure, which relieves the pressure from the transition portion to the pressure-receiving portion.

[0006] In an 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 an example of the secondary battery of the present invention, the stress relaxation structure includes a first stress relaxation structure located in the transition section, and the first stress relaxation structure is installed to continuously or intermittently surround the columnar section.

[0008] In an 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 an example of the secondary battery of the present invention, the stress relaxation structure includes a gap.

[0010] In an example of the secondary battery of the present invention, the transition zone has an unsmooth surface.

[0011] In an example of the secondary battery of the present invention, the stress relief structure includes a second stress relief structure located in the pressure-receiving portion. The pressure-receiving portion includes a first portion installed in the terminal hole and a second portion installed between the crimped portion and the end wall, and the first portion and the second portion are integrally molded.

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

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

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

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

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

[0017] In an example of the secondary battery of the present invention, the cylindrical battery includes a casing, one end of the casing is open and the other end is sealed, and terminal holes are 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-mentioned secondary batteries.

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

[0021] By providing a stress relaxation structure at least at one of the edge portion facing the caulked portion of the terminal hole, the position bent with respect to the columnar portion of the caulked portion, and the position where the insulating member and the caulked portion face each other, the compression force applied to the insulating member during riveting of the terminal can be reduced, and the caulked portion can avoid the stress concentration position of the insulating member, thereby improving the problem of breakage of the insulating member. At the same time, the present invention can also improve the problem of upward warping of the end portion of the insulating member away from the terminal, and further improve the assembly quality of the secondary battery.

Brief Description of Drawings

[0022] To more clearly explain the embodiments or means in the prior art of the present invention, the drawings required in the description of the embodiments or the prior art will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can also obtain other embodiments based on these drawings without creative activities.

[0023] [Figure 1] It is a schematic structural diagram of an example of the secondary battery of the present invention. [Figure 2] It is a schematic structural diagram of an electrode assembly of an example of the secondary battery of the present invention. [Figure 3] It is a partial enlarged view of part A in FIG. 1. [Figure 4] It is a partial enlarged view of part B in FIG. 3. [Figure 5] It is a schematic structural diagram before the terminal of Example 1 of the secondary battery of the present invention is riveted. [Figure 6] It is a schematic structural diagram before the terminal of Example 2 of the secondary battery of the present invention is riveted. [Figure 7] It is a schematic structural diagram before the terminal of Example 3 of the secondary battery of the present invention is riveted. [Figure 8] It is a schematic structural diagram before the terminal of Example 4 of the secondary battery of the present invention is riveted. [Figure 9] It is a schematic structural diagram after the terminal in an example of the secondary battery of the present invention is riveted. [Figure 10]This is a schematic diagram of the structure after the terminals have been riveted in another example of the secondary battery of the present invention. [Figure 11] This is a schematic diagram of the structure after the terminals have been riveted in yet another example of the secondary battery of the present invention. [Figure 12] This is a schematic diagram of the structure of an insulating member in an example of the secondary battery of the present invention. [Figure 13] This is a close-up view of section C in Figure 12. [Figure 14] This is a schematic diagram of the structure of an insulating member in another example of the secondary battery of the present invention. [Figure 15] This is a close-up view of section D in Figure 14. [Figure 16] This is a schematic diagram of the structure of an insulating member in yet another example of the secondary battery of the present invention. [Figure 17] This is a close-up view of section E in Figure 16. [Figure 18] This is a schematic diagram of an example of the battery pack of the present invention. [Figure 19] This is a schematic diagram of an example of the electronic device of the present invention. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below through specific examples. Those skilled in the art will readily understand other advantages and effects of the present invention from the contents disclosed herein. The present invention can be carried out or applied by yet another different specific embodiment, and the details of each item herein can also be modified or substituted in various ways, without departing from the spirit of the invention, based on different perspectives and applications. It should be noted that, under non-contradictory circumstances, the following embodiments and features within them can be combined with each other. Furthermore, the terms used in the embodiments of the present invention should be understood as being for the purpose of describing specific embodiments and not to limit the scope of protection of the present invention. In the following embodiments, test methods for which specific conditions are not specified usually follow conventional conditions or conditions recommended by each manufacturer.

[0025] Where the examples indicate numerical ranges, unless otherwise stated in the present invention, it should be understood that any two endpoints of each numerical range and any numerical value between those two endpoints can be selected. 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 prior art method, apparatus and materials that are similar or equivalent to the methods, apparatus and materials in the examples of the present invention.

[0026] It should be noted that terms such as “up,” “down,” “left,” “right,” “middle,” and “one” used herein are for convenience to clarify the explanation and do not limit the scope within which the present invention can be implemented. Any changes or adjustments to their relative relationships will be considered within the scope within 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, the electrode assembly being a component in which 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 terminals, the casing including end walls and side walls surrounding the end walls, with an opening at one end of the side walls, the electrode assembly being assembled inside the casing via the opening in the casing, the cover plate being used to cover the opening in the casing and achieve sealing, and the terminals passing through the end walls and electrically connected to the electrode assembly to derive the power generated by the electrode assembly.

[0029] To reduce the risk of short circuits, it is necessary to insulate the terminal and the end wall. Typically, an insulating material is placed between the terminal and the end wall, and the insulating material is positioned at least partially between the terminal and the end wall to insulate them.

[0030] In related technologies, when assembling a terminal and an end wall, the terminal is usually first inserted into the 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. Then, the outer end of the terminal is compressed to form a crimped portion, and the terminal is fixed to the end wall.

[0031] During the folding process of the crimped portion described above, the inside of the crimped portion is subjected to compressive stress, and the outside is subjected to tensile stress. As a result, the material located on the outside is stretched, and the material located on the inside flows under the action of compressive stress, causing material deformation to occur at the bent portion where the crimped portion and the insulating material come into contact, and a protrusion is formed. This protrusion comes into contact with a stress concentration point in 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, leading to a loss of the insulating function of the insulating material and further leading to a short circuit between the terminal and the end wall. In addition, the insulating material may warp at the end away from the terminal under the action of compressive force, further affecting the assembly quality of the battery.

[0032] Taking this into consideration, the present invention provides a means to solve the problem by installing a stress-relieving structure at least one of the edges of the terminal hole facing the crimping portion, the position where the crimping portion is bent relative to the columnar portion, and the position where the insulating member and the crimping portion face each other. This reduces the compressive force from the terminal to the insulating member during riveting, causing the crimping portion to avoid stress concentration points in the insulating member, thereby improving the problem of the insulating member breaking. At the same time, the present invention also improves the problem of the end of the insulating member away from the terminal, further improving the assembly quality of the secondary battery.

[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, the secondary battery 100 including a casing 110, an electrode assembly 120, terminals 140, and a cover plate 130.

[0034] Please refer to Figure 1. Figure 1 is a schematic diagram of the structure 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 achieved in various ways, as long as a stable seal and electrical connection relationship can be formed. For example, it can be formed by integral press molding, integral casting, or split welding. The way the side wall 112 surrounds is not limited and can be cylindrical or prismatic, or it can surround along any other closed-loop contour that fits with the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 surrounds the outer edge of the end wall 111 in a cylindrical shape, with a circular opening 113 formed at the end of the side wall 112 away from the end wall 111. A housing space is formed within the casing 110 surrounded by the end wall 111 and the side wall 112, and is used to house the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter size of the casing 110 can be determined based on the specific dimensions of the electrode assembly 120, for example, 18 mm, 21 mm, or 46 mm. The material of the casing 110 can be diverse, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent rusting of the casing 110 during long-term use, the surface of the casing 110 may be plated with a rust-preventive material such as metallic nickel.

[0035] Please refer to Figures 1 and 2. Figure 2 is a schematic diagram of the structure of an electrode assembly of an example of a secondary battery of the present invention. The electrode assembly 120 is housed in a casing 110 and is a component in the secondary battery 100 where an electrochemical reaction occurs. The casing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes an electrode plate and a separator 122, and the electrode plate and separator 122 are wound 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, and the positive electrode current collector 1211 has a first coated region 1212 coated with the positive electrode active material layer and a first uncoated region 1213 where the positive electrode active material layer is not coated. The first coated region 1212 and the first uncoated region 1213 are arranged along the axial direction of the casing 110, with the first uncoated region 1213 extending to the outside of the separator 122 at one end in the height direction of the secondary battery 100, forming a positive electrode tab 125 that is bent toward the axis of the casing 110 and stacked. The negative electrode plate 123 includes a negative electrode current collector 1231 and a negative electrode active material layer coated on the negative electrode current collector 1231, with a second coated region 1232 coated with the negative electrode active material layer and a second uncoated region 1233 not coated with the negative electrode active material layer 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 in the height direction of the secondary battery 100, forming a negative electrode tab 124 that is bent toward the axis of the casing 110 and stacked. The separator 122 is placed between the positive electrode plate 121 and the negative electrode plate 123 and insulates the positive electrode active material layer from the negative electrode active material layer. Taking the lithium-ion secondary battery 100 as an example, the material of the positive electrode current collector 1211 is aluminum, and the positive electrode active material layer contains the positive electrode active material, which is lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.The negative electrode current collector 1231 is made of copper, and the negative electrode active material layer contains a negative electrode active material, which is carbon or silicon, etc. The substrate of the separator 122 is PP (polypropylene) or PE (polyethylene), etc. To protect and insulate the cell, an insulating film may be coated on the outside of the cell, and the insulating film may be synthesized from PP, PE, PET, PVC or other polymer materials.

[0036] Please refer to Figures 1 and 2. Furthermore, in this 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 become positively charged, while the negative electrode tab 124 faces the opening 113, causing the casing 110 to become negatively charged by being electrically connected to the negative electrode tab 124. 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] Please refer to Figure 1. The cover plate 130 is sealed into 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 method of attaching the cover plate 130 may include, but is not limited to, mechanical sealing or welded 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 close-up view of part A of Figure 1, and Figure 4 is a close-up view of part B of Figure 3. A terminal hole 1111 is provided in the end wall 111, and the terminal 140 is fitted through the terminal hole 1111 and insulated from the end wall 111. One end of the terminal 140 facing the electrode assembly 120 is either directly electrically connected to the positive electrode tab 125 by passing through the end wall 111, or connected through an indirect relay connection. The structural form of the terminal 140 can be any suitable form that can pass through the end wall 111 and be electrically connected to the positive electrode tab 125 of the electrode assembly 120. For example, the cross-section may be circular, square, prismatic, or have an irregular contour that can achieve stable 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 columnar portion 142 that penetrates the terminal hole 1111 and a crimped portion 141 that is bent relative to the columnar portion 142 toward the outer edge of the end wall 111. The cross-section of the columnar portion 142 may be circular, square, prismatic, or other irregularly shaped contours that can achieve stable conductivity. For better sealing and mating effects, the columnar portion 142 preferably matches the terminal hole 1111; that is, the terminal hole 1111 corresponds to the shape of the columnar portion 142. In this embodiment, the cross-section of the columnar portion 142 is circular, and the circular design facilitates processing, assembly, and sealing. The portion where the crimped portion 141 and the columnar portion 142 connect is a transition portion 145. During the process of riveting the terminal 140, as the crimped portion 141 is folded 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 is subjected to tensile stress. The side of the transition portion 145 facing the outer edge of the end wall 111 is the inside, and the other side of the transition portion 145 opposite the inside is the outside. The material located on the outside is stretched, and the material located on the inside flows under compressive stress, so material deformation occurs in the transition portion 145 when the crimped portion 141 is folded back to the outer edge of the end wall 111. The terminal 140 is made of a conductive metallic material, and the material of the terminal 140 may be copper, nickel, or aluminum. In this embodiment, the material of the terminal 140 is aluminum, and by selecting aluminum, the crimping process can be easily carried out.

[0040] Please refer to 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 installed 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, for insulating and separating the end wall 111 from the terminal 140. The crimped portion 141 is formed by bending away from the axis of the terminal 140 and is connected to the columnar portion 142, acting as a limiter to restrict the separation of the terminal 140 from the end wall 111 and to compress and fix the insulating member 150. Specifically, the insulating member 150 includes a first insulator 152 and a second insulator 153 that are integrally molded. The first insulator 152 is located 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 crimped portion 141, used on one hand to isolate the crimped portion 141 from the end wall 111, and on the other hand to isolate the electrode assembly 120 from the end wall 111. 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, and since the pressure-receiving portion 151 is simultaneously compressed by the columnar portion 142 and the crimped portion 141, the pressure-receiving portion 151 is subjected to compressive stress when the transition portion 145 is bent.

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

[0042] Furthermore, a stress-relieving structure 160 is installed on at least one of the transition section 145 and the pressure-receiving section 151. The stress-relieving structure 160 is used to relieve the pressure applied to the insulating member 150 when the terminal 140 is riveted. That is, the stress-relieving structure 160 may be installed only on the transition section 145 or only on the pressure-receiving section 151. Regardless of whether the stress-relieving structure 160 is installed at either the transition section 145 or the pressure-receiving section 151, it can exert the effect of reducing the compressive force that the crimped section 141 applies to the insulating member 150. Of course, in some other embodiments, it may be chosen to install the stress-relieving structure 160 at both the transition section 145 and the pressure-receiving section 151. The installation position of the stress-relieving structure 160 on the transition section 145 and the pressure-receiving section 151 is not limited and may be installed at any position. The stress-relieving structure 160 may take various forms, such as grooves or chamfers. The cross-sectional shape of the groove may be an arc, rectangle, triangle, or other irregular shape, and the angle and shape of the chamfer may also vary and are not limited here. It is sufficient that the crimped portion 141 has the effect of mitigating the compressive force applied to the insulating member 150.

[0043] Please refer to 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 installed to restrict the separation between the terminal 140 and the end wall 111, and to provide an electrical connection to the electrode assembly 120 or the outside, thereby deriving the power generated by the electrode assembly 120. The cross-section of the limiting portion 143 may be circular, square, prismatic, or other irregularly shaped contour that can achieve stable conductivity, and in this embodiment, the cross-section of the limiting portion 143 is also circular.

[0044] Please refer to Figures 1, 3, and 4. Along the height direction of the secondary battery 100, the crimping portion 141 is located inside or outside the casing 110. Specifically, the crimping portion 141 and the limiting portion 143 are located on either side of the end wall 111, respectively, and rivet the terminal 140 to the end wall 111. The crimping portion 141 is located on the side of the end wall 111 closer 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 is electrically connected to an external power-using device to derive the power generated by the electrode assembly 120. In another embodiment, the limiting portion 143 is located on the side of the end wall 111 closer to the electrode assembly 120 and is 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 is electrically connected to an external power-using device to derive the power generated by the electrode assembly 120.

[0045] In one example of the secondary battery 100 of the present invention, the crimped portion 141 is located inside the casing 110, and the limiting portion 143 is located outside the casing 110. Since the crimped portion 141 is formed by riveting in a later stage, its shape is uncontrollable due to external influences, but the limiting portion 143 is processed in advance and its shape is regular and controllable. By installing the limiting portion 143 on the outside of the casing 110, both aesthetics and the safety of the electrical connection with external power-using devices are ensured.

[0046] Please refer to Figures 3 to 11. In an example of the secondary battery 100 of the present invention, the stress relaxation structure 160 includes a first stress relaxation structure 161 located in the transition section 145. The first stress relaxation structure 161 is installed to continuously or intermittently surround the columnar section 142, and the first stress relaxation structure 161 is located inside the transition section 145. In the intermittent surrounding installation, the number of intermittences and the length of the intermittences are not limited and may be freely designed according to the actual situation. The intermittent surrounding type of first stress relaxation structure 161 reduces the compressive force on the insulating member 150 when the terminal 140 is riveted, while also considering the crimping strength of the terminal 140. The continuous surrounding installation is more effective in mitigating the compressive force that the terminal 140 exerts on the insulating member 150, and if the wall thickness of this part is in the range of 0.3 mm to 1 mm, the crimped portion 141 of the terminal 140 can also have high strength. In this embodiment, the first stress relaxation structure 161 adopts a form that continuously surrounds the columnar portion 142.

[0047] Please refer to Figures 5 to 8. The first stress-relieving structure 161 at this position must be pre-set 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 where this first stress-relieving structure 161 is located. 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-relieving structure 161 reduces the amount of material that deforms the terminal body 144, provides a space for material flow occurring inside the transition portion 145 at the crimped portion 141, and further reduces the difficulty of bending.

[0048] For ease of understanding, the structure of the terminal 140 before the riveting process is described below. This first stress relief structure 161 is a groove installed in the outer wall of the terminal body 144, and the dimensions and shape of the groove are not limited and may be rectangular, arc-shaped, elliptical, triangular, waist-shaped, or other irregular shapes. Referring to Figures 5 to 8, some examples of the first stress relief structure 161 installed in the outer wall of the terminal body 144 are shown. Example 1, as shown in Figure 5, is a diagram showing the structure of the terminal of secondary battery example 1 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 Figure 6, is a diagram showing the structure of the terminal of secondary battery example 2 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 Figure 7, is a diagram showing the structure of the terminal of secondary battery example 3 of the present invention before riveting, and the cross-sectional shape of the first stress relief structure 161 is elliptical. As shown in Example 4, Figure 8, Figure 8 shows the structure of the secondary battery example 4 of the present invention before the terminals are riveted, and the cross-sectional shape of the first stress relaxation structure 161 is circular.

[0049] In addition to the different shapes and dimensions of the first stress-relieving structure 161 at the location in question, uncontrollable elements of material deformation will result in the first stress-relieving structure 161 forming a different shape after riveting is complete. This shape is not limited. Three general examples are shown below with reference to Figures 9 to 11.

[0050] In an example of the secondary battery 100 of the present invention, as shown in Figure 9, Figure 9 shows the structure of the secondary battery 100 of the present invention after the terminals have been 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 installed to intermittently or continuously surround the columnar portion 142, and 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 Figure 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 dimensional range can ensure the crimping strength of the crimped portion 141.

[0051] In another example of the secondary battery 100 of the present invention, as shown in Figure 10, Figure 10 shows the structure after the terminals have been riveted in another example of the secondary battery of the present invention. The first stress relief structure 161 includes a gap 1612, which is located in the transition section 145. When the amount of material flow accumulation caused by material deformation is approximately equal to the space reserved in the pre-set first stress relief structure 161, there is no room left in the groove of the first stress relief structure 161, and after riveting is completed, a gap 1612 is formed between the columnar section 142 and the crimped section 141.

[0052] In yet another example of the secondary battery 100 of the present invention, as shown in Figure 11, Figure 11 shows the structure after the terminals have been riveted in yet another example of the secondary battery of the present invention. The transition portion 145 is a non-smooth surface. According to prior knowledge, the inside of the transition portion 145 is subjected to compressive stress, and the outside is subjected to tensile stress. The material located on the outside is stretched, and the material located on the inside flows due to the action of the compressive stress. Therefore, at the bending point where the crimped portion 141 and the insulating member 150 come into contact, i.e., on the inside of the transition portion 145, material deformation occurs, and a protruding smooth transition surface is formed. If the amount of material flow deposited due to material deformation is approximately equal to the space reserved in the pre-set 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 crimped portion 141 and the columnar portion 142, which differs from the irregularly 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, that is, it reduces the amount of compression of the insulating member 150 by the crimped portion 141. This installation reduces the compressive force on the insulating member 150 when the terminal 140 is riveted.

[0053] Please refer to Figures 3 and 4. During the riveting process of terminal 140, the insulating member 150 is under the double compression action of the crimped portion 141 and the end wall 111. To mitigate the problem of the insulating member 150 warping due to fracture or deformation caused by compression, in an example of the secondary battery 100 of the present invention, the stress relief structure 160 includes a second stress relief structure 162 located on 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 crimped portion 141 and the end wall 111, thereby achieving insulation between terminal 140 and the end wall 111. It is necessary to explain that, when projected along the axial direction of the secondary battery 100, the portion where the second insulator 153 and the crimped portion 141 overlap is the second portion 1512, and the first portion 1511 and the second portion 1512 are integrally molded. The insulating member 150 for this installation is relatively easy to process and assemble, has good sealing performance, and the pressure receiving portion 151 is simultaneously pressed against the end wall 111 by the columnar portion 142 and the crimped portion 141.

[0054] Specifically, the second stress-relieving structure 162 may be located on the side of the pressure-receiving section 151 closer to the terminal 140, or on the side of the pressure-receiving section 151 closer to the end wall 111, and is not limited thereto. In this embodiment, the second stress-relieving structure 162 is located on the side of the pressure-receiving section 151 closer to the end wall 111, and the insulating member 150 has better strength in this installation. On the other hand, the second stress-relieving structure 162 may be installed on the first section 1511, on any position on the second section 1512, or on a combination of these two positions. Below, Figures 12 to 17 are combined to show three examples of the second stress-relieving structure 162 on the insulating member 150.

[0055] Please refer to Figures 3 to 4 and Figures 12 to 13. In an example of the secondary battery 100 of the present invention, the second stress relief structure 162 is located at the connection between the first part 1511 and the second part 1512, that is, part of the second stress relief structure 162 is located in the first part 1511 and part of the second part 1512. As shown in Figures 12 and 13, Figure 12 is a structural diagram of the insulating member in an example of the secondary battery of the present invention, and Figure 13 is a localized enlarged view of part C in Figure 12. The second groove 1621 is installed to continuously or intermittently surround the first part 1511, that is, the second stress relief structure 162 is located on the side facing the end wall 111. This installation reduces contact with the edge of the terminal hole 1111, on the one hand, as the first insulator 152 tends to bend upward towards the end wall 111 during the compression process, and on the other hand, it improves the problem of the first insulator 152 bending upward towards the electrode assembly 120 under the action of compressive force. Furthermore, the second stress-relaxing structure 162 includes a second groove 1621, and the cross-sectional shape of the second groove 1621 can be varied and is not limited thereto. For example, it can be rectangular, arc-shaped, waist-shaped, triangular, elliptical, any combination of the above shapes, or other irregular shapes. The second groove 1621 is installed to continuously or intermittently surround the first part 1511, and in the case of intermittent surrounding, the number and length of the intermittences are not limited and can be freely designed according to the actual situation. The intermittent surrounding type of second groove 1621 reduces the compressive force on the insulating member 150 when the terminal 140 is riveted, while also considering the structural strength of the insulating member 150. The continuous surrounding type is more effective in mitigating the compressive force that the terminal 140 applies to the insulating member 150. In this embodiment, the second groove 1621 is installed to continuously surround the first part 1511.

[0056] For another example of the secondary battery 100 of the present invention, please refer to Figures 3 to 4 and Figures 14 to 15. Figure 14 is a structural diagram of the insulating member in another example of the secondary battery of the present invention, and Figure 15 is a localized enlarged view of part D in Figure 14. The second stress relief structure 162 is located in the second part 1512, on the side facing the end wall 111, and the third groove 1622 is installed to continuously or intermittently surround the first part 1511. Its specific position in the second part 1512 is not limited. By installing the second stress relief structure 162 on the side facing the end wall 111, the first insulator 152 tends to warp towards the end wall 111 during the compression process, and the problem of the first insulator 152 warping towards the electrode assembly 120 under the action of compressive force can be improved. At the same time, the second stress relief structure 162 in this invention has the advantage of being easy to demold during the manufacturing process. Furthermore, the second stress relaxation structure 162 includes a third groove 1622, and the cross-sectional shape of the third groove 1622 can be varied and is not limited thereto. For example, it can be rectangular, arc-shaped, waist-shaped, triangular, elliptical, any combination of the above shapes, or other irregular shapes. The third groove 1622 is installed to continuously or intermittently surround the first part 1511, and in the case of intermittent surrounding, the number and length of the intermittences are not limited and can be freely designed according to the actual situation. The intermittent surrounding type of third groove 1622 reduces the risk of fracture of the insulating member 150 while also considering the structural strength of the insulating member 150. The continuous surrounding type is effective in better improving the problem of the insulating member 150 bending upward toward the electrode assembly 120 under the action of compressive force. In this embodiment, the third groove 1622 is installed to continuously surround the first part 1511.

[0057] For yet another example of the secondary battery 100 of the present invention, please refer to Figures 16 and 17. Figure 16 is a structural diagram of the insulating member in yet another example of the secondary battery of the present invention, and Figure 17 is a localized enlarged view of part E in Figure 16. The second stress relief structure 162 is located in the first part 1511, on the side facing the terminal hole 1111, and the fourth groove 1623 is installed to continuously or intermittently surround the first part 1511. Its specific location in the first part 1511 is not limited. By installing the second stress relief structure 162 on the side facing the end wall 111, the first insulator 152 tends to warp towards the end wall 111 during the compression process, and the problem of the first insulator 152 warping towards the electrode assembly 120 under the action of compressive force can be improved. Furthermore, the second stress relief structure 162 includes a fourth groove 1623, and there are various options for the cross-sectional shape of the fourth groove 1623, and this is not limited. For example, the grooves may be rectangular, arc-shaped, hip-shaped, triangular, elliptical, any combination of the above shapes, or other irregular shapes. The fourth groove 1623 is installed to continuously or intermittently surround the first part 1511. In the intermittent surrounding configuration, there are no limitations on the number and length of the intermittences, and it can be freely designed according to the actual situation. The intermittent surrounding configuration of the fourth groove 1623 reduces the risk of fracture of the insulating member 150 while also considering the structural strength of the insulating member 150. The continuous surrounding configuration is effective in better improving the problem of the insulating member 150 bending upward towards the electrode assembly 120 under the action of compressive force. In this embodiment, the fourth groove 1623 is installed to continuously surround the first part 1511.

[0058] During the crimping process of the terminal 140, the insulating member 150 is subjected to a double compressive action by the crimped portion 141 and the end wall 111. Therefore, by installing a stress-relieving structure 160 on the end wall 111, the effect of mitigating the compressive force that the terminal 140 exerts on the insulating member 150 can be achieved. For an example of the secondary battery 100 of the present invention, please refer to Figure 4. The stress-relieving structure 160 includes a third stress-relieving structure 163 installed on the edge of the terminal hole 1111 facing the crimped portion 141. This installation avoids contact between the edge of the end wall 111 and the corner where stress concentration occurs in the insulating member 150, and further improves the risk of fracture of the insulating member 150. The third stress-relieving structure 163 is a chamfer, and the shape of the chamfer is one or more of a wedge shape and an arc shape, and 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 an example of the secondary battery 100 of the present invention, the cylindrical battery includes a casing 110, one end of the casing 110 being open and the other end being 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 Figure 18. Figure 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, which are arranged inside 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 and protects the plurality of secondary batteries 100. It is necessary to explain that the battery pack 10 may also include parts other than the secondary batteries 100 of the present invention, such as a thermal management system for the battery pack 10 and a circuit board, and the battery pack 10 may be a battery module, a battery pack, an energy storage cabinet, etc. Further details are not described here.

[0063] Please refer to Figure 19. Figure 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 battery pack 10 described above. A work unit 11 is electrically connected to the battery pack 10 and can obtain power. As an example, the electronic device 1 is a vehicle, which may be a fuel-powered vehicle, a gas vehicle, or a new energy vehicle, and 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 work unit 11 is the vehicle body, and the battery pack 10 is installed at the bottom of the vehicle body and supplies power to the vehicle's movement or the operation of electrical components inside the vehicle. However, in some other embodiments, the electronic device 1 may be a mobile phone, a portable device, a laptop computer, a ship, space equipment, an electric toy, and a power tool, etc. Space equipment includes airplanes, rockets, space shuttles, spacecraft, etc. The work unit 11 may be a unit component that receives power from the battery pack 10 and performs a corresponding task, such as a fan blade rotation unit or a vacuum cleaner suction work unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys. Power tools include metal cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The embodiments of the present invention do not impose any special limitations on the electronic device 1 described above.

[0064] The secondary battery of the present invention provides a stress-relieving structure at at least one of the edges of the terminal hole facing the crimping portion, the position where the crimping portion is bent 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 during terminal riveting, allowing the crimping portion to avoid stress concentration points on the insulating member, thereby improving the problem of insulating member fracture. At the same time, the present invention can also improve the problem of warping at the end of the insulating member away from the terminal, thereby improving the assembly quality of the secondary battery. Therefore, the present invention effectively overcomes the practical problems of the prior art and has high utility and significance. The above embodiments are illustrative in explaining the principle and effects of the present invention and do not limit the present invention. Those skilled in the art can modify or change the above 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 idea of ​​the present invention should be included in the claims 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 Packs 11 Work Unit 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 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 Tabs 125 Positive Tab 130 Cover Plate 140 terminals 141 Crimping section 142 Columnar part 143 Restriction section 144 Terminal body 145 Transition part 150 Insulating material 151 Pressure-receiving section 1511 First part 1512 Second part 152 First Insulator 153 Second insulator 154 Third insulator 160 Stress relaxation structure 161 First stress relaxation structure 1611 First groove 1612 Gap 1613 Edge 162 Second stress relaxation structure 1621 Second groove 1622 Third groove 1623 Fourth groove 163 Third stress relaxation structure

Claims

1. A casing (110) including an end wall (111), the end wall (111) having a terminal hole (1111), The terminal (140) includes a columnar portion (142) that penetrates 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 the connection portion between the crimped portion (141) and the columnar portion (142) is a transition portion (145), and the transition portion (145) is such that material deformation occurs when the crimped portion (141) is folded back toward the outer edge of the end wall (111), This is for insulating the terminal (140) from the end wall (111), and includes a pressure-receiving portion (151) that contacts the terminal (140), the pressure-receiving portion (151) being an insulating member (150) that receives compressive stress when the transition portion (145) is bent, A stress-relieving structure (160) is provided in at least one of the transition section (145) and the pressure-receiving section (151), and the stress-relieving structure (160) is for relieving the pressure from the transition section (145) to the pressure-receiving section (151). The stress relaxation structure (160) includes a first stress relaxation structure (161) located in the transition section (145), and the first stress relaxation structure (161) is installed to continuously surround the columnar section (142). The first stress-relieving structure (161) includes a first groove (1611), A secondary battery characterized in that the first groove (1611) is provided on the surface of the transition portion (145) facing the insulating member (150).

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. The secondary battery according to claim 1, wherein the wall thickness at the position of the first groove (1611) is 0.3 mm to 1 mm.

4. The secondary battery according to claim 1, wherein the first stress relaxation structure (161) includes a gap (1612).

5. The secondary battery according to claim 1, wherein the transition portion (145) is a smooth transition surface.

6. The secondary battery according to any one of claims 1 to 5, 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.

7. The secondary battery according to claim 6, wherein the second stress-relieving structure (162) is located at the connection between the first portion (1511) and the second portion (1512), the second stress-relieving structure (162) includes a second groove (1621), and the second groove (1621) is installed to continuously or intermittently surround the first portion (1511).

8. The secondary battery according to claim 6, wherein the second stress-relieving structure (162) is located in the second portion (1512), and the second stress-relieving structure (162) includes a third groove (1622), the third groove (1622) is installed to continuously or intermittently surround the first portion (1511).

9. The secondary battery according to claim 6, wherein the second stress-relieving structure (162) is located in the first portion (1511), and the second stress-relieving structure (162) includes a fourth groove (1623), the fourth groove (1623) is installed to continuously or intermittently surround the first portion (1511).

10. The secondary battery according to claim 6, wherein the stress relief structure (160) includes a third stress relief structure (163) installed on the edge of the terminal hole (1111) toward the crimped portion (141), the third stress relief structure (163) is a chamfer, and the shape of the chamfer is one or more of a wedge shape and an arc shape.

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

12. The secondary battery according to claim 11, wherein the cylindrical battery includes the casing, the casing is open at one end and sealed at the other end, and the terminal hole is provided at the sealed end of the casing.

13. The secondary battery according to claim 12, wherein the casing is a steel case.

14. A battery pack characterized by including the secondary battery (100) described in claim 1.

15. An electronic device characterized by including the battery pack (10) described in claim 14.

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