Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a secondary battery, a battery pack and an electronic device, the secondary battery comprises a shell, an electrode assembly, a pole, a first high-temperature-resistant insulating part and a second high-temperature-resistant insulating part, the shell comprises an end wall, and the end wall is provided with a pole hole; the electrode assembly is arranged in the shell; the pole is fixed on the end wall and is electrically connected with the electrode assembly; the pole comprises a columnar part, a riveting part and a limiting part, and the riveting part and the limiting part are arranged at the two ends of the columnar part respectively; the columnar part penetrates through the pole hole, and the riveting part and the limiting part are located on the two sides of the end wall in the thickness direction respectively; the first high-temperature-resistant insulating part is clamped between the riveting part and the end wall; the second high-temperature-resistant insulating part is clamped between the limiting part and the end wall; the extension rate of the first high-temperature-resistant insulating part is larger than 5%, and the extension rate of the second high-temperature-resistant insulating part is lower than 5%. According to the utility model, the technical problem of insulation failure caused by easy breaking of the insulating part at the riveting position of the pole can be solved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a secondary battery, battery pack, and electronic device. Background Technology

[0002] Due to their high energy density and cost-effectiveness, rechargeable batteries have been widely used in the automotive industry. Currently, most rechargeable batteries typically have a positive terminal (post) and a negative terminal (steel casing). The post usually penetrates the end wall of the casing and is then fixed to the end wall of the casing by riveting.

[0003] In existing technologies, to achieve insulation between the positive and negative electrodes of a secondary battery, an insulating component is typically placed between the electrode post and the end wall. Therefore, at the electrode post riveting location, the riveted portion of the electrode post presses against and tightens against the insulating component, exerting a certain riveting pressure. However, in current secondary battery technology, at the electrode post riveting location, excessive riveting pressure often causes the insulating component to break, leading to insulation failure between the electrode post and the end wall. This results in the positive and negative electrodes of the secondary battery coming into contact, causing a short circuit and reducing the battery's safety performance. Utility Model Content

[0004] This utility model provides a secondary battery, a battery pack, and an electronic device to improve the technical problem that insulation components are easily crushed at the terminal post riveting position, resulting in insulation failure.

[0005] To achieve the above and other related objectives, this utility model provides a secondary battery, comprising: a shell, an electrode assembly, a terminal post, a first high-temperature resistant insulating component, and a second high-temperature resistant insulating component. The shell includes an end wall with a terminal post hole. The electrode assembly is disposed within the shell. The terminal post is fixed to the end wall and electrically connected to the electrode assembly. The terminal post includes a columnar portion, a riveting portion, and a limiting portion. The riveting portion and the limiting portion are respectively disposed at both ends of the columnar portion and extend from the columnar portion to the outer periphery of the end wall. The columnar portion penetrates the terminal post hole, and the riveting portion and the limiting portion are respectively located on both sides of the end wall thickness direction. The first high-temperature resistant insulating component is at least partially clamped between the riveting portion and the end wall to achieve insulation between the riveting portion and the end wall. The second high-temperature resistant insulating component is at least partially clamped between the limiting portion and the end wall to achieve insulation between the limiting portion and the end wall. The elongation of the first high-temperature resistant insulating component is greater than 5%, and the elongation of the second high-temperature resistant insulating component is less than 5%.

[0006] In one example of the secondary battery of this utility model, the first high-temperature resistant insulating component is an insulating rubber component, the second high-temperature resistant insulating component has a material hardness greater than HV800, and the melting point of both the first and second high-temperature resistant insulating components is greater than or equal to 300℃.

[0007] In one example of the secondary battery of this utility model, the riveting part is disposed on the outside of the shell, and the first high-temperature resistant insulating member is at least partially clamped between the riveting part and the wall on the side of the end wall away from the electrode assembly.

[0008] In one example of the secondary battery of this utility model, a sealing element is provided on the outer periphery of the second high-temperature resistant insulating member. The sealing element is at least partially clamped between the limiting part and the wall on the side of the end wall facing the electrode assembly, and the compression ratio of the sealing element is greater than 40%.

[0009] In one example of the secondary battery of this utility model, the radius of the electrode hole is R1, the radius of the columnar part is R2, and the radial width of the second high-temperature resistant insulating member is W, where W > R1 - R2.

[0010] In one example of the secondary battery of this utility model, the riveting part is disposed inside the shell, the first high-temperature resistant insulating member is clamped between the riveting part and the wall on the side of the end wall facing the electrode assembly, and the thermal weight loss rate of the first high-temperature resistant insulating member is less than 5%.

[0011] In one example of the secondary battery of this utility model, the diameter of the limiting part is D1, the diameter of the end wall is D2, and D1 / D2 is less than or equal to 0.4; a sealing element and an upper plastic are provided between the limiting part and the end wall. The sealing element is arranged around the outer periphery of the columnar part, and the upper plastic is arranged around the outer periphery of the sealing element and at least partially covers the outer periphery of the limiting part; a second high-temperature resistant insulating element is arranged around the outer periphery of the sealing element and is pressed between the upper plastic and the end wall.

[0012] In one example of the secondary battery of this utility model, the outer edge of the upper plastic covers the outer edge of the second high-temperature resistant insulating component.

[0013] In one example of the secondary battery of this utility model, the first high-temperature resistant insulating member extends radially along the end wall to isolate the electrode assembly from the end wall.

[0014] In one example of the secondary battery of this utility model, the secondary battery further includes a lower plastic, which is located on the side of the end wall facing the electrode assembly and isolates the electrode assembly from the end wall; along the thickness direction of the end wall, the projections of the lower plastic and the first high-temperature resistant insulating member on the end wall at least partially overlap.

[0015] This utility model also provides a battery pack, which includes any of the above-mentioned secondary batteries.

[0016] This invention also provides an electronic device that includes the aforementioned battery pack.

[0017] The secondary battery provided by this utility model includes a first high-temperature resistant insulating component sandwiched between the riveting portion and the end wall of the electrode post, achieving insulation between the riveting portion and the end wall. A second high-temperature resistant insulating component is sandwiched between the limiting portion and the end wall of the electrode post, achieving insulation between the limiting portion and the end wall, thereby achieving insulation between the electrode post and the casing. Since the first high-temperature resistant insulating component needs to withstand riveting pressure, its elongation is set to be greater than 5%. This gives the first high-temperature resistant insulating component good extensibility, reducing the probability of it breaking under riveting pressure and thus reducing the probability of insulation failure. Since the second high-temperature resistant insulating component mainly serves a supporting role during electrode post riveting, its elongation is set to be less than 5%. This provides more stable riveting support during the riveting process, preventing large deformation of the riveting portion due to excessive springback force, thus ensuring the riveting strength of the riveting portion. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of the overall structure of an example of a secondary battery of this utility model;

[0020] Figure 2 This is an axial sectional view of an example of a secondary battery according to this utility model;

[0021] Figure 3 for Figure 2 A magnified view of a portion of region A in the middle;

[0022] Figure 4 This is a schematic diagram of the electrode assembly structure of an example of the secondary battery of this utility model;

[0023] Figure 5 This is a partial enlarged view of the first high-temperature resistant insulating component, the second high-temperature resistant insulating component, and the electrode mounting position in an example of the secondary battery of this utility model;

[0024] Figure 6 This is a schematic diagram showing the installation positions of the first high-temperature resistant insulating component and the lower plastic component inside the casing in an example of the secondary battery of this utility model.

[0025] Figure 7This is a partial enlarged view of the connection position between the first high-temperature resistant insulating component and the lower plastic in an example of the secondary battery of this utility model;

[0026] Figure 8 This is a schematic diagram showing the installation position of the limiting part and the second high-temperature resistant insulating part inside the shell in an example of the secondary battery of this utility model.

[0027] Figure 9 This is a schematic diagram showing the installation position of the limiting part and the second high-temperature resistant insulating part inside the shell in another example of the secondary battery of this utility model.

[0028] Figure 10 This is a schematic diagram of an example of the battery pack of this utility model;

[0029] Figure 11 This is a schematic diagram of an example of the electronic device of this utility model.

[0030] Component designation explanation:

[0031] 100. Secondary battery; 110. Casing; 111. End wall; 1111. Terminal hole; 112. Side wall; 113. Opening; 120. Electrode assembly; 121. Positive electrode; 1211. Positive current collector; 1212. First coated area; 1213. First uncoated area; 122. Separator; 123. Negative electrode; 1231. Negative current collector; 1232. Second coated area; 1233. Second uncoated area; 124. Negative electrode tab; 125. Positive electrode tab; 130. Terminal; 131. Columnar portion; 13 2. Riveting part; 133. Limiting part; 141. First high-temperature resistant insulating component; 1411. First insulating part; 1412. Second insulating part; 142. Second high-temperature resistant insulating component; 150. Sealing component; 160. Upper plastic; 161. First plastic part; 162. Second plastic part; 163. Annular protrusion; 170. Lower plastic; 180. Cover plate; 190. Current collector; 200. Battery pack; 210. Housing; 211. First housing part; 212. Second housing part; 300. Electronic device; 310. Working part. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0033] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0034] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0035] Please see Figures 1 to 11 This utility model provides a secondary battery 100, a battery pack 200, and an electronic device 300. The secondary battery 100 can improve the technical problem that the electrode post 130 is prone to insulation failure at the riveting position by limiting the elongation rate of the first high-temperature resistant insulating member 141 between the riveting part 132 and the end wall 111 and the elongation rate of the second high-temperature resistant insulating member 142 between the limiting part 133 and the end wall 111. At the same time, it can also ensure the riveting strength between the electrode post 130 and the end wall 111.

[0036] Please see Figures 1 to 3 The present invention provides a secondary battery 100, which includes: a shell 110, an electrode assembly 120, a terminal post 130, a first high-temperature resistant insulating component 141, and a second high-temperature resistant insulating component 142.

[0037] Please see Figure 1 and Figure 2The housing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 111 and the side wall 112 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The circumference of the side wall 112 is not limited; it can be cylindrical or prismatic, or it can follow 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 is cylindrical, surrounding the outer edge of the end wall 111, with a circular opening 113 formed at the end of the side wall 112 facing away from the end wall 111. A receiving cavity is formed within the housing 110 formed by the end wall 111 and the side wall 112 to accommodate the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter of the housing 110 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, 46mm, etc. The shell 110 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent the shell 110 from rusting during long-term use, a layer of anti-rust material such as metallic nickel can be plated on the surface of the shell 110.

[0038] Please see Figure 2 and Figure 4 The electrode assembly 120 is disposed inside the housing 110 and is a component in the secondary battery 100 where electrochemical reactions occur. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes an electrode sheet and a separator 122, which are wound to form a wound structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive electrode sheet 121, a separator 122, and a negative electrode sheet 123 wound axially around the housing 110.

[0039] The positive electrode 121 includes a positive current collector 1211 and a positive active material layer coated on the positive current collector 1211. A first coated area 1212 coated with the positive active material layer and a first uncoated area 1213 uncoated with the positive active material layer are formed on the positive current collector 1211. The first coated area 1212 and the first uncoated area 1213 are arranged along the axial direction of the housing 110. The first uncoated area 1213 extends to one end of the secondary battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked positive electrode tab 125.

[0040] The negative electrode 123 includes a negative current collector 1231 and a negative active material layer coated on the negative current collector 1231. A second coated area 1232 coated with the negative active material layer and a second uncoated area 1233 uncoated with the negative active material layer are formed on the negative current collector 1231. The second coated area 1232 and the second uncoated area 1233 are arranged along the axial direction of the housing 110. The second uncoated area 1233 extends to the other end of the secondary battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked negative electrode tab 124.

[0041] A separator 122 is disposed between the positive electrode 121 and the negative electrode 123 to isolate the positive and negative active material layers. Taking a lithium-ion secondary battery 100 as an example, the positive current collector 1211 can be made of aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative current collector 1231 can be made of copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the separator 122 can be polypropylene (PP) or polyethylene (PE), etc. To protect and insulate the battery cell, an insulating film can also be wrapped around the outside of the battery cell. The insulating film can be synthesized from PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other polymer materials.

[0042] Please see Figure 2 and Figure 4 Furthermore, in this invention, the positive electrode tab 125 faces the end wall 111 or the opening 113, while the negative electrode tab 124 faces the other end of the housing 110. In this embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected to the terminal post 130, making the terminal post 130 positively charged. The negative electrode tab 124 faces the opening 113, and the housing 110 is electrically connected to the negative electrode tab 124, thus becoming negatively charged. However, in another embodiment, the negative electrode tab 124 can be connected to the terminal post 130, and the positive electrode tab 125 can be connected to the housing 110.

[0043] Please see Figure 2 The secondary battery 100 can also have a cover plate 180, which is sealed and installed on the opening 113. The outer edge shape of the cover plate 180 corresponds to the shape of the opening 113 and is connected to the side wall 112 to seal the opening 113. The installation method of the cover plate 180 includes, but is not limited to, mechanical sealing or welding sealing. In this embodiment, the cover plate 180 is sealed and plugged on the opening 113 by means of mechanical sealing.

[0044] Please see Figure 3 The electrode post 130 is fixed to the end wall 111 and electrically connected to the electrode assembly 120. Specifically, the end wall 111 is provided with an electrode post hole 1111, and the electrode post 130 is installed through the electrode post hole 1111 and insulated from the end wall 111. The end of the electrode post 130 facing the electrode assembly 120 can be directly electrically connected to the positive electrode tab 125 through the end wall 111, or it can be indirectly electrically connected to the positive electrode tab 125 through the current collector 190. Optionally, in this embodiment, the side of the electrode assembly 120 facing the end wall 111 is provided with a current collector 190, which is electrically connected to the positive electrode tab 125. The electrode post 130 passes through the end wall 111 and is electrically connected to the current collector 190, thereby achieving an indirect electrical connection with the positive electrode tab 125.

[0045] For details, please continue reading Figure 3 The electrode post 130 includes a columnar portion 131, a riveting portion 132, and a limiting portion 133. The columnar portion 131 penetrates the electrode post hole 1111 and is insulated from the electrode post hole 1111. The cross-section of the columnar portion 131 can be circular, square, prismatic, or other irregular contours that can achieve stable conductivity. Considering better sealing and fitting effects, preferably, the columnar portion 131 is adapted to the electrode post hole 1111, that is, the shape of the electrode post hole 1111 corresponds to that of the columnar portion 131. In this embodiment, the cross-section of the columnar portion 131 is circular. The circular design facilitates processing, assembly, and sealing.

[0046] Please see Figure 3 The riveting portion 132 and the limiting portion 133 are respectively disposed at both ends of the columnar portion 131 in the height direction, and both extend from the columnar portion 131 to the outer periphery of the end wall 111 in the radial direction. The riveting portion 132 is disposed on one side of the end wall 111 in the thickness direction, and the limiting portion 133 is disposed on the other side of the end wall 111 in the thickness direction. In one embodiment, please refer to... Figure 3 and Figure 5 The limiting portion 133 may be located on the side of the end wall 111 facing away from the electrode assembly 120, i.e., outside the housing 110, while the riveting portion 132 may be located on the side of the end wall 111 facing the electrode assembly 120, i.e., inside the housing 110. In another embodiment, please refer to... Figure 8 and Figure 9 Alternatively, the riveting portion 132 can be located on the side of the end wall 111 facing away from the electrode assembly 120, i.e., outside the housing 110; the limiting portion 133 can be located on the side of the end wall 111 facing the electrode assembly 120, i.e., inside the housing 110. The cross-section of the riveting portion 132 and the limiting portion 133 can be circular, square, prismatic, or other irregular contours that can achieve stable conductivity; this embodiment does not limit this.

[0047] Please see Figure 3 and Figure 8 The first high-temperature resistant insulating member 141 is at least partially clamped between the riveting portion 132 and the end wall 111 to achieve insulation between the riveting portion 132 and the end wall 111. Along the thickness direction of the end wall 111, the first high-temperature resistant insulating member 141 can be completely clamped between the riveting portion 132 and the end wall 111, or only partially clamped between them, as long as insulation between the riveting portion 132 and the end wall 111 is achieved. Specifically, the first high-temperature resistant insulating member 141 is disposed around the outer periphery of the columnar portion 131. The first high-temperature resistant insulating member 141 may or may not contact the columnar portion 131. The two end faces of the first high-temperature resistant insulating member 141 are in contact with the riveting portion 132 and the end wall 111, respectively. It should be noted that the first high-temperature resistant insulating component 141 may be in direct contact with the riveting part 132 and the end wall 111, or it may be in indirect contact with the riveting part 132 and the end wall 111. As long as the clamping arrangement of the first high-temperature resistant insulating component 141 between the riveting part 132 and the end wall 111 can be achieved, this embodiment does not limit it.

[0048] The second high-temperature resistant insulating member 142 is at least partially clamped between the limiting portion 133 and the end wall 111 to achieve insulation between the limiting portion 133 and the end wall 111. Along the thickness direction of the end wall 111, the second high-temperature resistant insulating member 142 may be completely clamped between the limiting portion 133 and the end wall 111, or only partially clamped between the limiting portion 133 and the end wall 111, as long as insulation between the limiting portion 133 and the end wall 111 is achieved. Similarly, the second high-temperature resistant insulating member 142 is also disposed around the outer periphery of the columnar portion 131. The second high-temperature resistant insulating member 142 may or may not contact the columnar portion 131. Along the thickness direction of the end wall 111, the two end faces of the second high-temperature resistant insulating member 142 contact the limiting portion 133 and the end wall 111, respectively. It should be noted that the second high-temperature resistant insulating component 142 may be in direct contact with the limiting part 133 and the end wall 111, or it may be in indirect contact with the limiting part 133 and the end wall 111. As long as the clamping arrangement of the second high-temperature resistant insulating component 142 between the limiting part 133 and the end wall 111 can be achieved, this embodiment does not limit it in this way.

[0049] The first high-temperature resistant insulating component 141 has an elongation greater than 5%, while the second high-temperature resistant insulating component 142 has an elongation less than 5%. The specific material of the first high-temperature resistant insulating component 141 is not limited; for example, it can be engineering plastics, such as soluble polytetrafluoroethylene (PFA), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), PP, polyphenylene sulfide (PPS), and polycarbonate (PC), or it can be an insulating rubber component. The specific material of the second high-temperature resistant insulating component 142 is also not limited; for example, it can be insulating ceramic material, fluoroplastics, etc.

[0050] Elongation is an important indicator in tensile testing of materials. It, along with other mechanical properties such as yield strength and tensile strength, collectively describes the mechanical properties of a material. Higher elongation indicates better plasticity and makes the material less prone to crushing under pressure. In this embodiment, the elongation of the first high-temperature resistant insulating component 141 and the second high-temperature resistant insulating component 142 can be calculated using the following formula: When testing the elongation rate of the first high-temperature resistant insulating component 141, it is only necessary to measure the length of the first high-temperature resistant insulating component 141 before stretching and the length at which it breaks to calculate the elongation rate. Similarly, when testing the elongation rate of the second high-temperature resistant insulating component 142, it is only necessary to measure the length of the second high-temperature resistant insulating component 142 before stretching and the length at which it breaks to calculate the elongation rate. It should be noted that the specific testing methods and procedures for the elongation rates of the first high-temperature resistant insulating component 141 and the second high-temperature resistant insulating component 142 can refer to the existing methods for testing the elongation rate of materials, and will not be elaborated here.

[0051] Since the first high-temperature resistant insulating component 141 is clamped between the riveting part 132 and the end wall 111, it needs to withstand the riveting pressure. In this embodiment, by setting the elongation rate of the first high-temperature resistant insulating component 141 to be greater than 5%, the first high-temperature resistant insulating component 141 can have better elongation, thereby reducing the probability of the first high-temperature resistant insulating component 141 breaking under the riveting pressure, and thus reducing the probability of the first high-temperature resistant insulating component 141 failing to maintain insulation. Since the second high-temperature resistant insulating component 142 is clamped between the limiting part 133 and the end wall 111, it mainly plays a supporting role when the pole post 130 is riveted. In this embodiment, by setting the elongation rate of the second high-temperature resistant insulating component 142 to less than 5%, a more stable axial support can be generated between the second high-temperature resistant insulating component 142 and the end wall 111 during the riveting process. This reduces the probability of large deformation of the riveted part 132 due to the large rebound force, which is beneficial to further improve the insulation stability between the pole post 130 and the end wall 111. At the same time, it can also ensure the riveting strength of the riveted part 132.

[0052] Please see Figure 3 and Figure 8 In one example of the secondary battery 100 of this utility model, the first high-temperature resistant insulating component 141 is an insulating rubber component, such as natural rubber, silicone rubber, fluororubber, etc. The material hardness of the second high-temperature resistant insulating component 142 is greater than HV800, and the melting point of both the first and second high-temperature resistant insulating components 141 and 142 is greater than or equal to 300℃. Since insulating rubber has good elasticity, setting the first high-temperature resistant insulating component 141 as an insulating rubber component allows it to also have good elasticity, thereby achieving good sealing performance between the riveted portion 132 and the end wall 111, eliminating the need for an additional sealing structure. Setting the material hardness of the second high-temperature resistant insulating component 142 to be greater than HV800 provides better support between it and the end wall 111, further reducing the probability of significant deformation of the riveted portion 132 due to the rebound force generated by the second high-temperature resistant insulating component 142, and further ensuring the stability of the insulation performance between the electrode post 130 and the end wall 111. The melting point of the first high-temperature resistant insulating component 141 and the melting point of the second high-temperature resistant insulating component 142 are both set to be greater than or equal to 300°C. This setting can meet the highest temperature requirement that the parallel secondary batteries 100 can reach inside when thermal runaway occurs during the use of the secondary batteries 100 in a group. This reduces the probability of the first high-temperature resistant insulating component 141 and the second high-temperature resistant insulating component 142 of the parallel secondary batteries 100 melting due to thermal runaway, which would cause insulation failure on the electrode post 130 side. This can reduce the risk of secondary short circuit caused by contact between the positive and negative electrodes of the parallel secondary batteries 100.

[0053] Please see Figure 8 and Figure 9 In one example of the secondary battery 100 of this utility model, the riveting portion 132 is disposed on the outside of the housing 110, and the first high-temperature resistant insulating member 141 is at least partially clamped between the riveting portion 132 and the wall of the end wall 111 on the side away from the electrode assembly 120. The first high-temperature resistant insulating member 141 may be partially clamped between the riveting portion 132 and the wall of the end wall 111 on the side away from the electrode assembly 120, or it may be entirely clamped between the riveting portion 132 and the wall of the end wall 111 on the side away from the electrode assembly 120. Optionally, in this embodiment, please refer to... Figure 8 A portion of the first high-temperature resistant insulating member 141 is clamped between the riveting portion 132 and the wall of the end wall 111 on the side opposite to the electrode assembly 120, while another portion extends into the interior of the electrode post hole 1111 and is clamped between the electrode post hole 1111 and the outer peripheral surface of the columnar portion 131, thereby achieving insulation between the electrode post hole 1111 and the columnar portion 131. This arrangement allows the first high-temperature resistant insulating member 141 to also seal the electrode post hole 1111, eliminating the need for an additional sealing structure.

[0054] In this embodiment, by setting the riveting part 132 on the outside of the housing 110, the limiting part 133 and the second high-temperature resistant insulating member 142 are respectively set inside the housing 110. When the secondary battery 100 experiences thermal runaway, the pressure inside the housing 110 increases, and the electrode post 130 is subjected to pressure towards the outside of the housing 110, thereby increasing the compressive force between the limiting part 133 and the end wall 111. Since the second high-temperature resistant insulating member 142 has higher hardness than the first high-temperature resistant insulating member 141, it is less prone to creep when compressed by the limiting part 133, and therefore less likely to be squeezed out from between the limiting part 133 and the end wall 111, thereby reducing the probability of insulation failure between the limiting part 133 and the end wall 111. Meanwhile, since the temperature inside the housing 110 will be higher than the temperature outside the housing 110 when thermal failure occurs, and the first high-temperature resistant insulating component 141 is made of plastic, it is easy to turn into liquid under extreme high temperature. Therefore, when the riveting part 132 is set on the outside of the housing 110, the corresponding first high-temperature resistant insulating component 141 will also be set on the outside of the housing 110. This can reduce the operating temperature of the first high-temperature resistant insulating component 141, thereby reducing the probability that the first high-temperature resistant insulating component 141 will be squeezed under high temperature and flow out from between the riveting part 132 and the end wall 111, resulting in insulation failure.

[0055] Optionally, provided that the riveting part 132 is located outside the housing 110, please refer to [reference needed]. Figure 8In one example of the secondary battery 100 of this utility model, a sealing member 150 is provided on the outer periphery of the second high-temperature resistant insulating member 142. The sealing member 150 is at least partially clamped between the limiting portion 133 and the wall of the end wall 111 facing the electrode assembly 120, and the compression ratio of the sealing member 150 is greater than 40%. The sealing member 150 is disposed around the outer periphery of the second high-temperature resistant insulating member 142. The inner annular surface of the sealing member 150 may or may not contact the outer peripheral surface of the second high-temperature resistant insulating member 142. The sealing member 150 may be completely clamped between the limiting portion 133 and the wall of the end wall 111 facing the electrode assembly 120, or it may be partially clamped between the limiting portion 133 and the wall of the end wall 111 facing the electrode assembly 120, and partially extend to the radially outer side of the limiting portion 133.

[0056] By setting the sealing element 150 and ensuring its compression ratio is greater than 40%, a good sealing effect can be achieved between the limiting part 133 and the end wall 111. Simultaneously, because the second high-temperature resistant insulating element 142 has high hardness, it is prone to breakage under significant vibration or impact. Therefore, by placing the sealing element 150 on the outer periphery of the second high-temperature resistant insulating element 142, the second high-temperature resistant insulating element 142 can be sealed between the limiting part 133 and the end wall 111. This prevents the second high-temperature resistant insulating element 142 from breaking due to vibration during riveting or external impact during use, thus reducing the probability of abnormal electrolyte circulation inside the housing 110.

[0057] Please see Figure 8 In one example of the secondary battery 100 of this utility model, the radius of the electrode hole 1111 is R1, the radius of the columnar portion 131 is R2, and the radial width of the second high-temperature resistant insulating member 142 is W, where W > R1 - R2. It should be noted that in one embodiment, please refer to... Figure 8 The space between the electrode hole 1111 and the columnar portion 131 may be filled with an insulating material, meaning that a portion of the first high-temperature resistant insulating member 141 extends into the space between the electrode hole 1111 and the columnar portion 131. In another embodiment, please refer to... Figure 9 Alternatively, the space between the pole post hole 1111 and the columnar portion 131 may not be filled with insulating material; instead, an insulating layer may be provided on the wall of the pole post hole 1111. In this embodiment, by ensuring that W > R1-R2, the installation error requirements of the columnar portion 131 within the pole post hole 1111 can be met under various working conditions. Therefore, it can be ensured that the second high-temperature resistant insulating component 142 is always sandwiched between the limiting portion 133 and the end wall 111, thereby reducing the probability of insulation failure due to assembly errors of the pole post 130 within the pole post hole 1111.

[0058] Please see Figure 3 and Figure 4In one example of the secondary battery 100 of this utility model, the riveting part 132 is disposed inside the housing 110, and correspondingly, the first high-temperature resistant insulating member 141 is also disposed inside the housing 110. That is, the first high-temperature resistant insulating member 141 is sandwiched between the riveting part 132 and the wall of the end wall 111 facing the electrode assembly 120, and the thermal weight loss rate of the first high-temperature resistant insulating member 141 is less than 5%.

[0059] It should be noted that the thermal weight loss rate of the first high-temperature resistant insulating component 141 was obtained by thermogravimetric analysis (TGA). TGA is a technique for measuring the mass change of a material under controlled temperature conditions, used to study the thermal stability, decomposition behavior, and composition of a sample. The specific measurement method of TGA is as follows:

[0060] Sample preparation: Prepare the sample to be tested, with a mass of approximately 5 mg, and distribute it evenly at the bottom of the crucible.

[0061] Instrument warm-up: Before the experiment, turn on the TGA instrument and warm it up for about 3 hours to ensure that the instrument is in normal working condition.

[0062] Parameter settings: Starting temperature: 25℃, heating rate: 10℃ / min, ending temperature: 500℃.

[0063] Baseline calibration: Place two empty crucibles and wait until the change in the instrument's mass display is very small before zeroing the instrument to calibrate the baseline.

[0064] Sample weighing and placement: Take out a crucible, put the experimental sample in it, and then place it into the instrument.

[0065] Test Startup: After the sample mass display stabilizes, start the test program and record the change in sample mass with temperature or time.

[0066] Data Acquisition and Analysis: The data acquisition and processing system of the TGA instrument converts the monitored quality changes into graphs or digital data for analysis and interpretation.

[0067] Test atmosphere: nitrogen.

[0068] Interpretation of results: By analyzing the thermogravimetric curves, parameters such as the thermal stability, decomposition temperature, and thermal weight loss rate of the material can be determined, and the thermal weight loss rate of the sample at 500℃ can be calculated.

[0069] When multiple sets of secondary batteries 100 are used in parallel and thermal runaway occurs, the temperature conducted to the interior of the parallel secondary batteries 100 is high. Since the first high-temperature resistant insulating component 141 is made of plastic, it is prone to thermal weight loss at certain high temperatures. A high thermal weight loss rate will correspondingly reduce the insulation performance of the first high-temperature resistant insulating component 141. In this embodiment, the thermal weight loss rate of the first high-temperature resistant insulating component 141 is less than 5%, which allows it to maintain good thermal stability even under thermal runaway conditions, thereby achieving a more stable insulation effect and further reducing the probability of secondary short circuits in the parallel secondary batteries 100.

[0070] Please see Figure 3 and Figure 4 In one example of the secondary battery 100 of this utility model, the diameter of the limiting part 133 is D1, the diameter of the end wall 111 is D2, and D1 / D2 is less than or equal to 0.4; a sealing member 150 and an upper plastic 160 are provided between the limiting part 133 and the end wall 111. The sealing member 150 is arranged around the outer periphery of the columnar part 131, and the sealing member 150 is sandwiched between the limiting part 133 and the wall of the end wall 111 on the side away from the electrode assembly 120. The sealing member 150 can be coaxially arranged with the columnar part 131 or not. The sealing member 150 can contact the outer peripheral surface of the columnar part 131 or not. Optionally, in this embodiment, the sealing member 150 is coaxially arranged with the columnar part 131, and the inner ring surface of the sealing member 150 contacts the outer peripheral surface of the columnar part 131 to form a better sealing connection with the columnar part 131.

[0071] An upper plastic 160 is disposed around the outer periphery of the sealing member 150. The material of the upper plastic 160 can be PFA, PBT, LCP, PP, PPS, or PC, etc., and is not limited thereto. The upper plastic 160 includes a first plastic part 161 and a second plastic part 162 that are connected to each other. The first plastic part 161 covers the outer periphery of the limiting part 133. One end of the second plastic part 162 is connected to the first plastic part 161, and the other end extends to the space between the limiting part 133 and the wall of the end wall 111 on the side away from the electrode assembly 120. A second high-temperature resistant insulating member 142 is disposed around the outer periphery of the sealing member 150 and is pressed between the upper plastic 160 and the end wall 111. The second high-temperature resistant insulating member 142 may or may not contact the outer ring surface of the sealing member 150. Optionally, in this embodiment, the second high-temperature resistant insulating member 142 does not contact the outer ring surface of the sealing member 150, that is, an installation gap is provided between the two. This arrangement reduces the radial compressive force on the second high-temperature resistant insulating component 142 when the seal 150 deforms. Specifically, the second high-temperature resistant insulating component 142 being pressed between the upper plastic 160 and the end wall 111 means that, along the thickness direction of the end wall 111, the second high-temperature resistant insulating component 142 is pressed between the second plastic portion 162 and the wall of the end wall 111 on the side away from the electrode assembly 120, that is, the two end faces of the second high-temperature resistant insulating component 142 are pressed and abutted against the second plastic portion 162 and the wall of the end wall 111 on the side away from the electrode assembly 120, respectively.

[0072] In this embodiment, by limiting D1 / D2 to less than or equal to 0.4, the diameter of the limiting part 133 can be restricted, thus reserving sufficient welding space on the outer side of the housing 110, i.e., the side of the end wall 111 facing away from the electrode assembly 120, to meet the electrical connection requirements when the secondary batteries 100 are used in groups. Simultaneously, placing the sealing ring on the side close to the columnar part 131 not only facilitates better sealing performance between the electrode post 130 and the mounting hole, but also reduces the deformation of the electrode post 130 when the seal 150 rebounds, thereby reducing the probability of seal failure. Furthermore, pressing the second high-temperature resistant insulating component 142 between the end wall 111 and the upper plastic 160 not only reduces the installation space occupied by the second high-temperature resistant insulating component 142 in the radial direction of the end wall 111, but also reduces the probability of the second high-temperature resistant insulating component 142 coming off between the end wall 111 and the upper plastic 160 after it breaks due to the compression of the upper plastic 160.

[0073] When the second high-temperature resistant insulating component 142 is pressed between the upper plastic 160 and the end wall 111, in order to further reduce the risk of the second high-temperature resistant insulating component 142 breaking and coming off, please refer to [further details]. Figure 3 and Figure 5In one example of the secondary battery 100 of this utility model, the outer edge of the upper plastic 160 covers the outer edge of the second high-temperature resistant insulating member 142. Specifically, the side of the second plastic portion 162 facing the electrode assembly 120 includes an annular protrusion 163, which protrudes from the side facing the electrode assembly 120. The annular protrusion 163 is coaxially arranged with the second high-temperature resistant insulating member 142, and the inner annular surface of the annular protrusion 163 contacts the outer peripheral surface of the second high-temperature resistant insulating member 142, thereby achieving the arrangement that the outer edge of the upper plastic 160 covers the outer edge of the second high-temperature resistant insulating member 142. By covering the outer edge of the second high-temperature resistant insulating component 142 with the outer edge of the upper plastic 160, the second high-temperature resistant insulating component 142 can be sealed between the second plastic part 162 and the end wall 111 by the annular protrusion 163. This can further reduce the probability that the second high-temperature resistant insulating component 142 will break and come out between the end wall 111 and the upper plastic 160, which is beneficial to further improve the insulation effect between the end wall 111 and the limiting part 133.

[0074] Please see Figure 3 and Figure 4 In one example of the secondary battery 100 of this utility model, a first high-temperature resistant insulating member 141 extends radially along the end wall 111 to isolate the electrode assembly 120 from the end wall 111. The first high-temperature resistant insulating member 141 includes a first insulating portion 1411 and a second insulating portion 1412 connected to each other. The first insulating portion 1411 abuts against the wall of the end wall 111 on the side facing the electrode assembly 120. Along the radial direction of the end wall 111, one end of the first insulating portion 1411 extends between the riveting portion 132 and the end wall 111, and the other end of the first insulating portion 1411 extends toward the outer periphery of the end wall 111 to isolate the electrode assembly 120 from the end wall 111. Along the thickness direction of the end wall 111, one end of the second insulating portion 1412 is connected to the first insulating portion 1411, and the other end of the second insulating portion 1412 extends between the electrode hole 1111 and the columnar portion 131, forming a fully enclosed structure around the electrode hole 1111 to isolate the columnar portion 131 from the electrode hole 1111. It should be noted that, in another embodiment, the first high-temperature resistant insulating member 141 may only have the first insulating portion 1411 and not the second insulating portion 1412. This configuration also achieves insulation isolation between the electrode assembly 120 and the end wall 111 by the first high-temperature resistant insulating member 141. This configuration allows the first high-temperature resistant insulating member 141 to achieve insulation isolation between the end wall 111 and the riveting portion 132, as well as insulation isolation between the end wall 111 and the electrode assembly 120, without requiring additional insulating members between the end wall 111 and the electrode assembly 120. Therefore, it reduces the assembly steps of the secondary battery 100 and improves assembly efficiency.

[0075] Please see Figure 6 and Figure 7In one example of the secondary battery 100 of this utility model, the secondary battery 100 further includes a lower plastic 170, which is located on the side of the end wall 111 facing the electrode assembly 120, and the lower plastic 170 is disposed around the columnar portion 131; the material of the lower plastic 170 is any one of PP, PPS, PC, PFA, PBT and LCP. Furthermore, along the thickness direction of the end wall 111, the projections of the lower plastic 170 and the first high-temperature resistant insulating component 141 on the end wall 111 at least partially overlap. The manner of overlap is not limited. For example, along the thickness direction of the end wall 111, the outer edge of the first high-temperature resistant insulating component 141 may be located between the end wall 111 and the lower plastic 170, or the inner edge of the lower plastic 170 may be located between the end wall 111 and the first high-temperature resistant insulating component 141, or the outer periphery of the first high-temperature resistant insulating component 141 and the inner edge of the lower plastic 170 may be connected by an insertion method, as long as the projections of the lower plastic 170 and the first high-temperature resistant insulating component 141 on the end wall 111 at least partially overlap. By ensuring that the projections of the lower plastic 170 and the first high-temperature resistant insulating component 141 on the end wall 111 at least partially overlap, this arrangement reduces the probability of axial mating gaps between the lower plastic 170 and the first high-temperature resistant insulating component 141, thereby mitigating the technical problem of short-circuit risk between the end wall 111 and the current collector 190. Simultaneously, since the lower plastic 170 and the first high-temperature resistant insulating component 141 are separate components, they can be made of different materials, allowing for greater design flexibility. Furthermore, the separate design reduces the transmission of riveting force generated during the riveting process of the pole post 130 to the lower plastic 170, thus improving the problem of the lower plastic 170 lifting and enhancing assembly quality.

[0076] Please see Figure 10 In one embodiment of the battery pack 200 of this utility model, the battery pack 200 includes a housing 210 and at least one secondary battery 100; the housing 210 includes a first housing portion 211 and a second housing portion 212, which cover each other to form an accommodating space, in which multiple secondary batteries 100 are accommodated, and the multiple secondary batteries 100 can be connected in series and / or in parallel. The battery pack 200 can be, for example, a battery module, a battery pack, etc.

[0077] Please see Figure 11In one example of the electronic device 300 of this utility model, the electronic device 300 includes a working part 310 and a battery pack 200. The working part 310 is electrically connected to the battery pack 200 to obtain electrical power. The working part 310 can be a unit component capable of obtaining electrical power from the battery pack 200 and performing corresponding work, such as a fan blade rotation unit, a vacuum cleaner suction unit, or a wheel drive unit in an electric vehicle. The electronic device 300 can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding 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, etc. This utility model embodiment does not impose special limitations on the above-mentioned electronic device 300. In one embodiment of the electronic device 300 of this utility model, the electronic device 300 is a vehicle, the working part 310 is the vehicle body, and the battery pack 200 is fixedly installed on the vehicle body, thereby providing driving force for the vehicle to operate.

[0078] The secondary battery provided by this utility model includes a first high-temperature resistant insulating component sandwiched between the riveting portion and the end wall of the electrode post, achieving insulation between the riveting portion and the end wall. A second high-temperature resistant insulating component is sandwiched between the limiting portion and the end wall of the electrode post, achieving insulation between the limiting portion and the end wall, thereby achieving insulation between the electrode post and the casing. Since the first high-temperature resistant insulating component needs to withstand riveting pressure, its elongation is set to be greater than 5%. This gives the first high-temperature resistant insulating component good extensibility, reducing the probability of it breaking under riveting pressure and thus reducing the probability of insulation failure. Since the second high-temperature resistant insulating component mainly serves a supporting role during electrode post riveting, its elongation is set to be less than 5%. This provides more stable riveting support during the riveting process, preventing large deformation of the riveting portion due to excessive springback force, thus ensuring the riveting strength of the riveting portion.

[0079] Therefore, this utility model effectively overcomes some practical problems in the prior art, thus possessing high utilization value and significance. The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit it. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A secondary battery characterized by comprising: The application relates to a secondary battery, comprising: a shell comprising an end wall provided with a pole hole; an electrode assembly arranged in the shell; a pole fixed to the end wall and electrically connected with the electrode assembly; the pole comprises a columnar part, a riveting part and a limiting part, the riveting part and the limiting part are arranged at two ends of the columnar part respectively, and both extend from the columnar part to the outer periphery of the end wall; the columnar part penetrates through the pole hole, and the riveting part and the limiting part are located on two sides of the thickness direction of the end wall respectively; a first high-temperature-resistant insulating part at least partially clamped between the riveting part and the end wall to realize insulation between the riveting part and the end wall; a second high-temperature-resistant insulating part at least partially clamped between the limiting part and the end wall to realize insulation between the limiting part and the end wall; wherein the elongation of the first high-temperature-resistant insulating part is greater than 5%, and the elongation of the second high-temperature-resistant insulating part is less than 5%.

2. The secondary battery according to claim 1, characterized by The first high-temperature-resistant insulating part is an insulating rubber part, the material hardness of the second high-temperature-resistant insulating part is greater than HV800, and the melting point of the first high-temperature-resistant insulating part and the melting point of the second high-temperature-resistant insulating part are both greater than or equal to 300 DEG C.

3. The secondary battery according to claim 2, characterized by The riveting part is arranged outside the shell, and the first high-temperature-resistant insulating part is at least partially clamped between the riveting part and the wall body on the side of the end wall away from the electrode assembly.

4. The secondary battery according to claim 3, characterized by The outer periphery of the second high-temperature-resistant insulating part is provided with a sealing part, the sealing part is at least partially clamped between the limiting part and the wall body on the side of the end wall facing the electrode assembly, and the compression rate of the sealing part is greater than 40%.

5. The secondary battery according to claim 4, characterized by The radius of the pole hole is R1, the radius of the columnar part is R2, the radial width of the second high-temperature-resistant insulating part is W, and W>R1-R2.

6. The secondary battery according to claim 2, characterized by The riveting part is arranged inside the shell, the first high-temperature-resistant insulating part is clamped between the riveting part and the wall body on the side of the end wall facing the electrode assembly, and the thermal weight loss rate of the first high-temperature-resistant insulating part is less than 5%.

7. The secondary battery according to claim 6, characterized by The diameter of the limiting part is D1, the diameter of the end wall is D2, and D1 / D2 is less than or equal to 0.4; a sealing part and an upper plastic are arranged between the limiting part and the end wall, the sealing part is arranged around the outer periphery of the columnar part, the upper plastic is arranged around the outer periphery of the sealing part and at least partially covers the outer periphery of the limiting part; the second high-temperature-resistant insulating part is arranged around the outer periphery of the sealing part and is pressed between the upper plastic and the end wall.

8. The secondary battery according to claim 7, characterized by The outer edge of the upper plastic covers the outer edge of the second high-temperature-resistant insulating part.

9. The secondary battery according to claim 6, characterized by The first high-temperature-resistant insulating part extends in the radial direction of the end wall to insulate the electrode assembly and the end wall.

10. The secondary battery according to claim 6, characterized by The secondary battery further comprises a lower plastic, the lower plastic is located on the side of the end wall facing the electrode assembly and insulates the electrode assembly and the end wall; in the thickness direction of the end wall, the projection of the lower plastic and the first high-temperature-resistant insulating part on the end wall at least partially overlaps.

11. A battery pack, characterized by The application relates to a secondary battery, comprising any one of claims 1 to 10.

12. An electronic device, comprising: The application relates to a battery pack, comprising claim 11.

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