Secondary batteries, battery packs and electrical devices

Abstract

A secondary battery includes electrode terminals comprising a through-hole portion and a first fixing portion and a second fixing portion disposed on both sides of the end wall in the axial direction; an insulating member surrounding the through-hole portion, comprising a first insulating member disposed between the end wall and the first fixing portion and a second insulating member disposed between the end wall and the second fixing portion; wherein the first fixing portion is a riveting portion of the electrode terminal, a portion of the first insulating member forms a compressed portion in a compressed state between the end wall and the first fixing portion, and / or, the second fixing portion is a riveting portion of the electrode terminal, a portion of the second insulating member forms a compressed portion in a compressed state between the end wall and the second fixing portion; the contact surface where the compressed portion contacts the riveting portion has a point of deepest compression, said point not overlapping with the orthographic projection of the glue inlet in the axial direction. The purpose of this utility model is to provide a secondary battery, a battery pack, and an electrical device to at least improve the sealing performance of the secondary battery.

Description

Technical Field

[0001] The embodiments of this utility model relate to a secondary battery, a battery pack, and an electrical device. Background Technology

[0002] In secondary batteries, an insulating component is placed between the electrode terminals and the end walls of the casing to insulate both. As the performance of secondary batteries continues to improve, the requirements for their sealing performance are also increasing. Currently, there is room for improvement in the sealing performance between the electrode terminals and the end walls of existing secondary batteries. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a secondary battery, battery pack and power device to at least improve the sealing performance of the secondary battery.

[0004] To achieve the above objectives, this utility model provides a secondary battery, comprising: a housing, wherein the housing has an opening at one end in the axial direction and an end wall at the other end opposite to the opening, the end wall having a mounting hole; an electrode assembly disposed within the housing; an electrode terminal fixed to the end wall and electrically connected to the electrode assembly, the electrode terminal including a through portion passing through the mounting hole, and a first fixing portion and a second fixing portion disposed on both sides of the end wall in the axial direction; and an insulating member surrounding the through portion, including a first insulating member disposed between the end wall and the first fixing portion and an insulating member disposed between the end wall and the second fixing portion. The second insulating member is provided; wherein the first fixing part is the riveting part of the electrode terminal, a portion of the first insulating member forms a compressed part in a compressed state between the end wall and the first fixing part, and / or, the second fixing part is the riveting part of the electrode terminal, a portion of the second insulating member forms a compressed part in a compressed state between the end wall and the second fixing part; the insulating member includes an inlet, the contact surface of the compressed part contacting the riveting part is a compressed curved surface, and in a cross-sectional view through the axis of the insulating member, the contact surface has a point that is most deeply compressed, and the point does not overlap with the orthographic projection of the inlet in the axial direction.

[0005] The beneficial technical effect of this application is as follows: In the embodiments of this application, when the first fixing part is a riveting part of the electrode terminal, the point where the compressed part of the first insulating member in a compressed state contacts the first fixing part, and the point where the compressed part contacts the first fixing part, does not overlap with the orthogonal projection of the glue inlet in the axial direction. At this point, the first insulating member is most tightly connected to the first fixing part and the end wall, i.e., the sealing performance is best. The glue inlet is avoided from this point to prevent damage to the sealing performance due to its presence. When the second fixing part is a riveting part of the electrode terminal, the point where the compressed part of the second insulating member in a compressed state contacts the second fixing part, and the point where the compressed part contacts the second fixing part, does not overlap with the orthogonal projection of the glue inlet in the axial direction. At this point, the second insulating member is most tightly connected to the second fixing part and the end wall, i.e., the sealing performance is best. The glue inlet is avoided from this point to prevent damage to the sealing performance due to its presence.

[0006] In some embodiments, the insulating member has a through hole through which the through portion passes, and the minimum distance between the point and the glue inlet along the radial direction of the insulating member is Y mm, the difference between the maximum outer diameter of the insulating member and the minimum diameter of the through hole is Z mm, and 0.3≤Y / Z≤0.8.

[0007] In some embodiments, the insulating element has a layered region, and the point does not overlap with the layered region in the axial direction.

[0008] In some embodiments, the second fixing portion is located outside the housing, and the second insulating member further includes an outer edge portion surrounding the outer periphery of the second fixing portion and an inner edge portion located between the through portion and the end wall. The glue inlet is located within the orthogonal projection range of the outer edge portion in the axial direction and is located on the side of the outer edge portion facing the end wall.

[0009] In some embodiments, the second fixing part is a riveting part of the electrode terminal. The electrode terminal includes a terminal body and a sealing pin. The terminal body has a hollow part on the side away from the electrode assembly. The sealing pin is welded to the terminal body and seals the hollow part. The terminal body is welded to the current collector at the bottom of the hollow part. The electrode terminal is electrically connected to the electrode assembly through the current collector. The material of the second insulating part is soluble polytetrafluoroethylene.

[0010] In some embodiments, the number of glue inlets is N, where N ≥ 2, and the N glue inlets are disposed on the same surface perpendicular to the axial direction and are equidistantly distributed along the circumference of the second insulating member.

[0011] In some embodiments, the first fixing portion is located inside the housing and is a riveting portion of the electrode terminal. The first insulating member further includes a first extension portion located between the through portion and the end wall, and a second extension portion located outside the compression portion of the first insulating member. The first insulating member includes an adhesive inlet, which is located on the outer side wall of the second extension portion away from the compression portion.

[0012] In some embodiments, the first insulating member is made of soluble polytetrafluoroethylene. The secondary battery further includes a current collector connected between the electrode terminal and the electrode assembly. The insulating member also includes a third insulating member for insulating the current collector and the end wall. The third insulating member surrounds the first insulating member. The second extension is fixed to the third insulating member in the axial direction of the housing. The height difference in the axial direction between the surface of the second extension facing the electrode assembly and the surface of the compressed portion of the first insulating member facing the electrode assembly is W mm. The thickness of the second extension is X mm, where W < 0.5 × X.

[0013] Embodiments of this application also provide a battery pack, including any of the aforementioned secondary batteries.

[0014] Embodiments of this application also provide an electrical device including the aforementioned battery pack. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It is worth noting that, according to industry standard practice, the components are not drawn to scale and are only used for illustrative purposes. In fact, for clarity of discussion, the dimensions of the components can be arbitrarily increased or decreased.

[0016] Figure 1 A schematic diagram is shown when the electrical device in an embodiment of this application is a vehicle.

[0017] Figure 2 A battery pack according to an embodiment of this application is shown.

[0018] Figure 3 A top view of a secondary battery according to a first embodiment of this application is shown.

[0019] Figure 4 It shows along Figure 3 A cross-sectional view taken from the VV line.

[0020] Figure 5It shows Figure 4 A magnified view of region J in the middle.

[0021] Figure 6 It shows Figure 4 Enlarged cross-sectional view of region K in the middle.

[0022] Figure 7 It shows Figure 6 A magnified view of the L region.

[0023] Figure 8 Another cross-sectional view of a secondary battery according to a first embodiment of this application is shown.

[0024] Figure 9 It shows Figure 8 A magnified view of region M in the middle.

[0025] Figure 10 A top perspective view (isometric view) of a first insulating member according to a first embodiment of this application is shown.

[0026] Figure 11 A bottom perspective view of the second insulating member according to the first embodiment of this application is shown.

[0027] Figure 12 It shows Figure 11 A magnified view of the S-region.

[0028] Figure 13 A bottom view of the second insulating member according to the first embodiment of this application is shown.

[0029] Figure 14 It shows along Figure 13 A cross-sectional view taken from the NN line.

[0030] Figure 15 It shows Figure 14 A magnified view of the U-region.

[0031] Figure 16 It shows along Figure 13 A cross-sectional view taken from the OO line.

[0032] Figure 17 A top view of the second insulating member according to the first embodiment of this application is shown.

[0033] Figure 18 It shows along Figure 17 A cross-sectional view taken from the PP line.

[0034] Figure 19 It shows Figure 18 A magnified view of the Q region.

[0035] Figure 20A top view of a secondary battery according to a second embodiment of this application is shown.

[0036] Figure 21 It shows along Figure 20 A sectional view taken from the BB line.

[0037] Figure 22 It shows Figure 21 A magnified view of region E in the middle.

[0038] Figure 23 It shows Figure 21 Enlarged cross-sectional view of region F in the middle.

[0039] Figure 24 It shows Figure 21 Enlarged cross-sectional view of region G in the middle.

[0040] Figure 25 A top perspective view of the first insulating member according to a second embodiment of this application is shown.

[0041] Figure 26 A bottom perspective view of the first insulating member according to a second embodiment of this application is shown.

[0042] Figure 27 A bottom view of the first insulating member according to a second embodiment of this application is shown.

[0043] Figure 28 A top view of the first insulating member according to a second embodiment of this application is shown.

[0044] Figure 29 It shows along Figure 28 A cross-sectional view taken from the TT line.

[0045] Figure 30 It shows Figure 29 A magnified view of region I in the middle.

[0046] Figure 31 This is a schematic diagram of the electrode assembly of an example of a secondary battery according to this utility model. Detailed Implementation

[0047] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0048] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0049] The terms “approximately,” “generally,” “substantial,” “substantial,” “about,” and “approximately” used herein are used to indicate and explain minor variations. For example, when used in conjunction with numerical values, the above terms may refer to a range of variation less than or equal to ±10% of the corresponding numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. As another embodiment, the thickness of a film or layer being “substantially uniform” may refer to the average thickness of the film or layer being less than or equal to ±10% of the standard deviation, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. The term "substantially coplanar" can refer to two surfaces that are within 50 μm along the same plane (such as within 40 μm, 30 μm, 20 μm, 10 μm, or 1 μm along the same plane). If, for example, two components overlap or overlap within 200 μm, 150 μm, 100 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, or 1 μm, then the two components can be considered "substantially aligned." If the angle between the two surfaces or components is, for example, 90°...

[0050] If the angle is ±10° (such as ±5°, ±4°, ±3°, ±2°, ±1°, ±0.5°, ±0.1°, or ±0.05°), then the two surfaces or components can be considered "substantially perpendicular". When used in conjunction with an event or situation, the terms "approximately", "generally", "substantially", "materially", "about", and "approximately" can refer to the exact occurrence of the event or situation as well as the very close approximation of the occurrence.

[0051] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0052] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0053] In existing technologies, the insulating component is not compressed by the electrode terminals, thus failing to provide a sealing effect. Furthermore, the glue inlet is recessed from the surface of the insulating component, resulting in poor sealing at the interface between the insulating component and the housing. The location of the glue inlet interferes with the location where the insulating component is riveted, and if there are delamination areas in the insulating component, it will affect the sealing performance at the riveted location.

[0054] See Figure 1 This application provides an electrical device 1000, which includes a battery pack 300. The working part of the electrical device 1000 is connected to the battery pack 300 to obtain electrical power. As an example, the electrical device 1000 is a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc., but are not limited thereto. The battery pack 300 is, for example, located at the bottom of the vehicle body 1001 and provides electrical power for the vehicle's operation or the operation of electrical components within the vehicle. However, in other embodiments, the electrical device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part is a unit component capable of obtaining electrical power from the battery pack 300 and performing corresponding work, such as the fan blade rotation unit of a fan, the vacuuming unit of a vacuum cleaner, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat 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 application does not impose any special limitations on the aforementioned electrical device 1000.

[0055] See Figure 2 This application also provides a battery pack 300, which includes secondary batteries 100. In one embodiment of the battery pack 300, the battery pack 300 includes a housing 101, a cover 102, and multiple secondary batteries 100. The multiple secondary batteries 100 are placed in the housing 101 and are connected in series or parallel, or a combination of series and parallel connections. The cover 102 covers the housing 101 to protect the multiple secondary batteries 100. It should be noted that the battery pack 300 may also include a battery thermal management system, circuit boards, etc., in addition to the secondary batteries 100. The battery pack 300 can be a battery module, a battery pack, an energy storage cabinet, etc.; these will not be described in detail here.

[0056] Figure 3 A top view of a secondary battery 100 according to a first embodiment of this application is shown. Figure 4 It shows along Figure 3 A cross-sectional view taken from the VV line. Figure 5 It shows Figure 4 Enlarged view of region J, where the positive current collector 141 and electrode assembly 120 are not shown. Figure 6 It shows Figure 4 Enlarged cross-sectional view of region K, where the sealing pin 47, positive current collector 141 and electrode assembly 120 are not shown. Figure 7 It shows Figure 6 A magnified view of the L region.

[0057] Figure 8 Another cross-sectional view of a secondary battery 100 according to a first embodiment of this application is shown. Figure 9 It shows Figure 8 A magnified view of region M in the middle. (The image was captured.) Figure 8 The face of the sectional view shown is... Figure 4 Different, among them Figure 8 We cut to the 74mm inlet.

[0058] Figure 10 A top perspective view (isometric view) of the first insulating member 71 according to the first embodiment of this application is shown. Figure 11 A bottom perspective view of the second insulating member 72 according to the first embodiment of this application is shown. Figure 12 It shows Figure 11 A magnified view of the S-region.

[0059] Figure 13 A bottom view of the second insulating member 72 according to the first embodiment of this application is shown. Figure 14 It shows along Figure 13 A cross-sectional view taken from the NN line. Figure 15 It shows Figure 14 A magnified view of the U-region. Figure 16 It shows along Figure 13 A cross-sectional view taken from the OO line. Figure 17 A top view of the second insulating member 72 according to the first embodiment of this application is shown. Figure 18 It shows along Figure 17 A cross-sectional view taken from the PP line. Figure 19 It shows Figure 18 A magnified view of the Q region.

[0060] Figure 20 A top view of a secondary battery 100 according to a second embodiment of this application is shown. Figure 21 It shows along Figure 20 A sectional view taken from the BB line. Figure 22 It shows Figure 21 A magnified view of region E in the middle. Figure 23 It shows Figure 21 Enlarged cross-sectional view of region F in the middle, where sealing nail 47 is not shown. Figure 24 It shows Figure 21 Enlarged cross-sectional view of region G in the middle, where sealing nail 47 is not shown.

[0061] Figure 25 A top perspective view of the first insulating member 71 according to the second embodiment of this application is shown. Figure 26 A bottom perspective view of the first insulating member 71 according to the second embodiment of this application is shown. Figure 27 A bottom view of the first insulating member 71 according to the second embodiment of this application is shown. Figure 28 A top view of the first insulating member 71 according to the second embodiment of this application is shown. Figure 29 It shows along Figure 28 A cross-sectional view taken from the TT line. Figure 30 It shows Figure 29 A magnified view of region I in the middle.

[0062] An embodiment of this application provides a secondary battery 100, which includes a housing 10 and a cover plate 30. The housing 10 has an end wall 14 and a side wall 12. The housing 10 is located at one end of its axial direction A. Figure 4 The lower end shown is an opening, and the end wall 14 is located at the other end opposite to the opening.

[0063] The sidewall 12 surrounds the end wall 14. As long as a stable seal and electrical connection can be formed, the connection between the end wall 14 and the sidewall 12 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The circumference of the sidewall 12 is not limited; it can be cylindrical or prismatic, or it can follow any other closed-loop contour that matches the end wall 14. In this embodiment, the outer edge of the end wall 14 is circular, and the sidewall 12 is cylindrical, surrounding the outer edge of the end wall 14, with a circular opening formed at the end of the sidewall 12 facing away from the end wall 14. A cavity is formed within the housing 10 formed by the end wall 14 and the sidewall 12 to accommodate the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter of the housing 10 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, or 46mm. The shell 10 can be made of various materials, such as copper, iron, aluminum, steel with nickel layer, aluminum alloy, etc. In order to prevent the shell 10 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 10.

[0064] Figure 31This is a schematic diagram of the electrode assembly 120 of an example of the secondary battery 100 of this utility model. The electrode assembly 120 is disposed inside the housing 10 and is a component in the secondary battery 100 where electrochemical reactions occur. The housing 10 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 around the housing 10 axially.

[0065] 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 A of the housing 10. 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 10 to form a stacked positive electrode tab 125.

[0066] 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 10. 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 10 to form a stacked negative electrode tab 124.

[0067] 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.

[0068] In this embodiment, the secondary battery 100 further includes a cover plate 30, which is sealed to the opening (e.g., by welding the cover plate 30 to the side wall 12). Electrode terminals 40 are fixed to the end wall 14 and electrically connected to the electrode assembly; electrode terminals 40 can also be referred to as terminals. In this invention, the positive electrode tab 125 faces the end wall 14 or the opening of the housing 10, while the negative electrode tab 124 faces the other end of the housing 10. In this embodiment, the positive electrode tab 125 faces the end wall 14 and is electrically connected to the electrode terminal 40 via the current collector 141, making the electrode terminal 40 positively charged. The negative electrode tab 124 faces the opening, and the housing 10 is electrically connected to the negative electrode tab 124 via the negative current collector 142, thus making it negatively charged. However, in another embodiment, the negative electrode tab 124 can be connected to the electrode terminal 40, and the positive electrode tab 125 can be connected to the housing 10.

[0069] The electrode terminal 40 includes a through portion 44 that passes through a mounting hole in the end wall 14, and a first fixing portion 41 and a second fixing portion 42 disposed on the inner and outer sides of the end wall 14 in the axial direction A. An insulating member 70 surrounds the through portion 44 and is at least partially clamped between the first fixing portion 41 and the end wall 14, and / or at least partially clamped between the second fixing portion 42 and the end wall 14.

[0070] The first fixing part 41 is disposed inside the housing 10, and the second fixing part 42 is disposed outside the housing 10. The insulating member 70 includes a first insulating member 71 disposed inside the housing 10 and a second insulating member 72 disposed outside the housing 10. The first insulating member 71 is at least partially clamped between the first fixing part 41 and the end wall 14, and the second insulating member 72 is at least partially clamped between the second fixing part 42 and the end wall 14. The insulating member 70 provides electrical insulation between the electrode terminal 40 and the end wall 14 of the housing 10. In some embodiments, the first insulating member 71 and the second insulating member 72 may also be referred to as the lower plastic and the upper plastic, respectively.

[0071] The secondary battery 100 also includes a sealing element 90, which surrounds the through portion 44 of the electrode terminal 40. At least a portion of the sealing element 90 is held between the first fixing portion 41 and the end wall 14. The sealing element 90 can also be called a sealing ring, and it is a component that plays a major sealing role between the electrode terminal 40 and the end wall 14. The material of the sealing element 90 is, for example, fluororubber. The first insulating member 71 and the second insulating member 72 are respectively provided with helium detection grooves 718 and 728. After the first insulating member 71, the second insulating member 72, the electrode terminal 40, and the end wall 14 are installed, the helium detection grooves 718 and / or 728 can be used to detect whether the sealing element 90 is missing, thus preventing poor sealing of the secondary battery 100 due to missing sealing element 90.

[0072] See Figure 5 , Figure 6 and Figure 9 In the first embodiment of this application, the electrode terminal 40 is externally riveted, and the second fixing part 42 located outside the housing 10 is a riveted part. The second fixing part 42 of the electrode terminal 40 originally extends parallel to the axial direction A, that is, it is vertical. The second fixing part 42 passes through the mounting hole of the end wall 14 from the inside of the housing 10 outward. By flanging or pressing the second fixing part 42, the second fixing part 42 is made to extend radially R beyond the mounting hole of the end wall 14 and bend toward the end wall 14. A portion of the second insulating member 72 is squeezed between the end wall 14 and the second fixing part 42 to form a compressed part 725 in a compressed state (see Figure 9 ).

[0073] See Figures 22 to 24 In the second embodiment of this application, the electrode terminal 40 is internally riveted, and the first fixing part 41 located inside the housing 10 is a riveted part. The first fixing part 41 of the electrode terminal 40 originally extends parallel to the axial direction A, that is, it is vertical. The first fixing part 41 is inserted into the mounting hole of the end wall 14 from the outside of the housing 10. By expanding or pressing the first fixing part 41, the first fixing part 41 extends beyond the mounting hole of the end wall 14 in the radial direction R and bends toward the end wall 14. A portion of the first insulating member 71 is squeezed between the end wall 14 and the first fixing part 41 to form a compressed part 715 in a compressed state.

[0074] Commonly used plastic materials include soluble polytetrafluoroethylene (PFA), polypropylene (PP), and polybutylene terephthalate (PBT). PFA has a melting point of approximately 310℃; its melt flow index (MFR, tested according to ISO R1133) is greater than or equal to 9 g / 10 min, for example, it includes two specifications: 14 g / 10 min and 30 g / 10 min; its yield strength is 10-20 MPa, and it has good thermal stability. PP has an MFR of 8.0 g / 10 min; its melting point is approximately 164-170℃; and its yield strength is 25-40 MPa. PBT has a melting point of approximately 225-275℃; compared to PFA, it has poorer thermal stability. Comparing the three materials, PFA exhibits better high-temperature resistance, crack resistance, resilience, and corrosion resistance.

[0075] In this embodiment, the portion of the insulating member 70 at the riveting location uses PFA material because PFA has low yield strength and better elasticity, thus providing a certain sealing performance. Compared to PFA, PP plastics are more brittle and prone to plastic deformation. When compressed by the electrode terminal 40, PP material is prone to cracking, affecting the sealing performance. Therefore, in the first embodiment, the material of the second insulating member 72 compressed by the second fixing part 42 is preferably PFA; in the second embodiment, the material of the first insulating member 71 compressed by the first fixing part 41 is preferably PFA, which is beneficial to the sealing effect at the electrode terminal 40.

[0076] See Figure 4 The electrode terminal 40 is electrically connected to the electrode assembly 120 through the manifold 141. For example, the manifold 141 is welded to the positive electrode tab 125 of the electrode assembly 120, and then the electrode terminal 40 and the manifold 141 are welded from the outside of the housing 10 by through-welding.

[0077] See Figure 4 and Figure 5 The second fixing part 42 is the riveting part of the electrode terminal 40, see [link / reference]. Figure 22 The first fixing part 41 is the riveting part of the electrode terminal 40. The electrode terminal 40 includes a terminal body (first fixing part 41, through part 44, second fixing part 42) and a sealing pin 47. The side of the terminal body opposite to the electrode assembly 120 has a hollow part 46. The bottom of the hollow part 46 is welded to the current collector 141. The thinned part of the electrode terminal 40 is used for welding to the current collector 141, which improves the situation of thick welding thinning when welding from the outside, reduces welding difficulty, and avoids the diaphragm in the electrode assembly being burned by excessive welding temperature. The sealing pin 47 is welded to the terminal body and seals the hollow part 46. Heat is generated during welding, so the material of the second insulating member 72, which is close to the weld pool 49 formed by welding, needs to be heat-resistant. In addition, heat is also generated when welding the electrode terminals 40 and busbars of multiple secondary batteries 100 together.

[0078] In summary, the electrode terminal 40 is riveted to the end wall 14 via the first fixing part 41 or the second fixing part 42 to compress the insulating part 70, which is made of PFA. Compared with other plastic materials (such as PP, PPS, etc.), PFA has better elasticity and a certain degree of compressibility. When compressed, it provides a sealing effect at the interface between the insulating part 70 and the metal (electrode terminal 40 and end wall 14). The first fixing part 41 or the second fixing part 42 compresses the insulating part 70 to increase the contact between the insulating part 70, the housing 10 and the electrode terminal 40, thus achieving a certain sealing effect. At the same time, PFA has a high melting point and good heat resistance, preventing ambient heat from affecting its sealing performance.

[0079] In the first embodiment where the electrode terminal 40 is externally riveted, the external second insulating member 72 is preferably made of PFA material, which can withstand high temperatures and also provide partial sealing. The internal first insulating member 71, which does not require high temperature resistance and sealing, can be made of PP material or PFA material, preferably PP material, to reduce costs.

[0080] In the second embodiment where the electrode terminal 40 is riveted internally, the external second insulating member 72 is preferably made of PFA material to withstand high temperatures; the internal first insulating member 71 is preferably made of PFA material to provide partial sealing.

[0081] For example, see Figure 13 When forming the second insulating component 72, liquid material is injected into the mold through the inlet 74 (therefore, the inlet 74 is the entrance for the molten plastic slurry to enter the mold of the first insulating component 71). The molten plastic slurry flows from the inlet 74 along the circumferential direction C of the second insulating component 72 to both sides of the inlet 74. If the number of inlets 74 is 1, they converge at the symmetrical position of the inlets 74 about the axial direction A to form a weld line 75. If the number of inlets 74 distributed along the circumferential direction C is N, and N≥2, then the number of weld lines 75 is also N, and a weld line is formed in the middle of every two adjacent inlets 74 along the circumferential direction C.

[0082] For example, see Figure 27 When forming the first insulating component 71, liquid material is injected into the mold through the inlet 74 (therefore, the inlet 74 is the entrance for the molten plastic slurry to enter the mold of the first insulating component 71). The molten plastic slurry flows along the circumferential direction C to both sides of the inlet 74. If the number of inlets 74 is 1, they converge at the symmetrical position of the inlets 74 about the axial direction A to form a weld line 75. If the number of inlets 74 distributed along the circumferential direction C is N, N≥2, then the number of weld lines 75 is also N, and a weld line 75 is formed in the middle of every two adjacent inlets 74 along the circumferential direction C.

[0083] For the insulating member 70, factors affecting the sealing performance at the electrode terminal 40 include: the sealing performance of the interface between the insulating member 70 and the electrode terminal 40, and the end wall 14 during riveting, as well as the sealing performance of the material of the insulating member 70 itself. In the first embodiment, the second insulating member 72 is compressed; in the second embodiment, the first insulating member 71 is compressed.

[0084] In the first embodiment of this application, the second fixing part 42 is a riveting part of the electrode terminal 40. The contact surface between the compression part 725 of the second insulating member 72 in a compressed state and the second fixing part 42 is a compressed curved surface. In a cross-sectional view passing through the axis of the second insulating member 72, this contact surface has a point 729 that is most deeply compressed (i.e., the point closest to the end wall 14). Point 729 does not overlap with the orthographic projection of the glue inlet 74 on the axial direction A. Along the axial direction A, the second insulating member 72 is most tightly connected to the second fixing part 42 and the end wall 14 at point 729, i.e., the sealing performance is the best. The glue inlet 74 and point 729 are avoided to prevent the presence of the glue inlet 74 from damaging the sealing performance at this point. The end face 727 of the second insulating member 72, which is compressed to the deepest point by the second fixing part 42, extends in the axial direction A and passes through point 729. The orthographic projection of the end face 727 and the glue inlet 74 does not overlap, so as to avoid the end face 727 overlapping with the glue inlet 74, which would affect the sealing of the interface between the compression part 725 and the end wall 14 and the second fixing part 42 due to the presence of the glue inlet 74.

[0085] In the second embodiment of this application, the first fixing part 41 is the riveting part of the electrode terminal 40. The contact surface between the compression part 715 of the first insulating member 71 in a compressed state and the first fixing part 41 is a compressed curved surface. In a cross-sectional view passing through the axis of the first insulating member 71, this contact surface has a point 719 that is compressed the most (i.e., the point closest to the end wall 14). The point 719 and the orthographic projection of the glue inlet 74 on the axial direction A do not overlap. Along the axial direction A, the first insulating member 71 is most tightly connected to the first fixing part 41 and the end wall 14 at point 719, i.e., the sealing performance is the best. The glue inlet 74 and point 719 are avoided to prevent the presence of the glue inlet 74 from damaging the sealing performance at this point. The end face 717 of the first insulating member 71, which is compressed to the deepest point by the first fixing part 41, extends in the axial direction A and passes through point 729. The orthographic projection of the end face 727 and the glue inlet 74 does not overlap, so as to avoid the end face 717 overlapping with the glue inlet 74, which would affect the sealing of the interface between the compression part 715 and the end wall 14 and the first fixing part 41 due to the presence of the glue inlet 74.

[0086] In the injection molding process of PFA materials, the shear rate of the molten plastic slurry represents the rate of velocity change between adjacent fluid layers during melt flow. When the melt passes through narrow runners or gates, the flow velocity difference between the outer and central layers is significant, creating a shearing effect, at which point the shear rate reaches a high value. Therefore, the shear rate is an important parameter describing the internal velocity gradient of the molten material flowing in the runner and cavity. It directly affects the material's flowability, viscosity, and the quality of the final product.

[0087] In the injection molding process of PFA material, the phenomenon of adjacent fluid layers during melt flow is a typical characteristic of laminar flow. During injection molding, the molten PFA material flows in a laminar state. The characteristics of laminar flow are that the fluid flows in parallel layers with no lateral mixing between layers; motion is transmitted only through shear stress. The velocity distribution of the flow layers is as follows: for the flow layer close to the mold wall, due to the adsorption of plastic molecules to the mold wall, the velocity of the flow layer close to the wall is the minimum (boundary layer effect); for the central flow layer, the velocity of the flow layer far from the wall is the maximum, forming a parabolic velocity gradient, i.e., a distribution that is fast in the middle and slow on both sides; for the relative sliding of adjacent flow layers, the velocity difference generated by the shear stress creates interlayer frictional resistance, hindering the overall flow. For circular tubes or cavities, taking a cylindrical flow channel as an example, the radial velocity distribution R is parabolic, with the highest velocity at the center and zero at the wall. For mold cavities or flow channels with non-circular cross-sections (such as rectangular or irregular cavities), the flow layer still follows the rule of "fast at the center and slow at the edge", but the velocity gradient may vary depending on the cross-sectional shape.

[0088] PFA materials have a melt flow index greater than or equal to 9 g / 10 min. Compared to materials with a lower melt flow index (such as PP), they have a faster flow rate, resulting in different shear stresses at the flow channel edges and center, and a large flow rate difference, which leads to the aforementioned stratification phenomenon. Therefore, in applications such as... Figure 19 and Figure 30 On the cross-section shown (which also corresponds to the cross-section of the mold cavity or runner), the melt is divided into multiple parallel thin layers (flow layers), each with a different flow velocity, creating a stratification region 79 (manifested as a gap) along the axial direction A. The stratification region 79 can be observed, for example, using a 4K resolution testing device like the Phoenix Vltomelx M300. Specific reasons for the formation of the stratification region 79 include: wall adhesion, where the flow layer adhering closely to the mold wall becomes stationary due to adhesion, forming a low-velocity boundary layer; shear stress transmission, where the high-speed movement of the central flow layer drives adjacent flow layers through shear stress, creating a gradient velocity distribution; and viscosity influence, where higher dynamic viscosity results in greater interlayer shear stress and more pronounced stratification. The stratification region 79 is parallel to the material flow direction. The tensile strength of the insulating component 70 decreases due to the formation of the stratification region 79. The tensile strength of the insulating component 70 without the formation of the stratification region 79 is approximately 10-25 MPa; after the formation of the stratification region 79, the tensile strength may decrease by 50%.

[0089] In the insulating member 70 of this application, the distance between the layered region 79 and the edge of the compression portion 715, 725 along the axial direction A is greater than or equal to 0.02 mm, so as to avoid the layered region 79 being too close to the interface between the insulating member 70 and the metal (electrode terminal 40 and end wall 14), which would result in poor interface sealing reliability.

[0090] Reference Figure 9 and Figure 15 In the embodiment of external riveting, the second fixing part 42 is a riveting flange structure, and the second insulating member 72 has an intermediate portion 726 between the end wall 14 and the second fixing part 42. The intermediate portion 726 overlaps with the end wall 14 and the second fixing part 42 along the axial direction A in the orthogonal projection of the second insulating member 72 with the second fixing part 42 in the same direction as the compression portion 725 (the compression portion 725 extends radially R from the position where the second insulating member 72 is first compressed) and has a compressed curved surface. The second insulating member 72 includes an outer edge portion 722 surrounding the outer edge of the electrode terminal 40 and an inner edge portion 724 located between the through portion 44 and the end wall 14. The glue inlet 74 is located within the orthogonal projection range of the outer edge portion 722 along the axial direction A and is located on the side of the outer edge portion 722 facing the end wall 14. The inner edge 724, located between the through-hole 44 and the end wall 14, is confined within the mounting hole. The outer edge 722, surrounding the outer edge of the electrode terminal 40, further confines the second fixing part 42. This facilitates assembly while ensuring that the second fixing part 42 can press down on the second insulating member 72, minimizing the offset between them. This results in a more even distribution of force on the second insulating member 72, preventing excessive force in certain areas and thus avoiding damage. It also improves the sealing performance of the secondary battery 100 at the second insulating member 72 and prevents the second fixing part 42 from crossing the second insulating member 42 and contacting the end wall 14, ensuring that the second insulating member 72 provides insulation between the electrode terminal 40 and the end wall 14. The inner edge 724 has a small radial width R, making it difficult to arrange the injection die, therefore it is not suitable to provide an injection port 74. The injection port 74 is located on the outer edge 722, avoiding the compression part 725, to prevent the injection port 74 from being present at a stress position, which could affect the interface seal between the second insulating member 72 and the end wall 14. The glue inlet 74 is located on the side of the outer edge 722 facing the end wall 14. The second insulating part 72 can be identified by a CCD camera to prevent incorrect installation of the second insulating part 72. In addition, the glue inlet 74 is not visible from the outside of the secondary battery 100, making the appearance of the secondary battery 100 more aesthetically pleasing.

[0091] For example, see Figures 12 to 15The insulating component 70 (second insulating component 72) also includes N injection ports 76 (used to assist in fixing the injection mold head during injection molding). N injection inlets 74 are correspondingly arranged within the N injection ports 76. The depth of the injection ports 76 is H mm, where H mm ranges from 0.1 mm to 0.4 mm. And / or, at least a portion of the width of the injection port 76 gradually increases along the radial direction R of the housing 10 away from the mounting hole. The injection port 76 is a recess from the surface 77 to fix the injection mold and assist the injection mold in accurately positioning and matching the injection inlets 74. Furthermore, after injection molding is completed and the material has cured, due to the adhesive properties of the colloid, when the insulating component 70 is pulled out of the mold, stringing will occur at the injection inlets 74, i.e., outward protrusion. By controlling the depth of the injection ports 76 within the range of 0.1 mm to 0.4 mm, the protrusion height caused by stringing is accommodated. Furthermore, the depth of the injection port 76 should not be too large (e.g., greater than 0.4 mm) to avoid affecting the overall strength of the insulating component 70. The width of the injection port 76 gradually decreases radially from the outside to the inside to prevent the inner end of the injection port 76 from occupying the internal area of ​​the surface 77 (which is in close contact with the end wall 14 during riveting pressure) and affecting the sealing performance of the interface between the insulating component 70 and the end wall 14. In a preferred embodiment, the injection port 76 is a U-shaped groove.

[0092] See Figure 19 The glue inlet 74 is located in the middle portion 726 of the second insulating member 72, which is clamped between the second fixing portion 42 and the end wall 14, and is located on the surface 77 of the second insulating member 72 facing the end wall 14. See also Figure 30 The inlet 74 is located on the outer wall of the first insulating member 71, radially away from the mounting hole. The flow rate of the molten plastic slurry at the inlet 74 is high, resulting in longer and more numerous delamination regions 79 compared to other locations. In this embodiment, the compressed portions 715 and 725 of the insulating member 70, where the compression portion is in a compressed state, have their deepest compressed end faces 717 and 727 (aligned with the outer edge of the riveting portion radially R in the axial direction A) that do not overlap with the orthographic projection of the inlet 74 in the axial direction A. This avoids the long and numerous delamination regions 79 in the insulating member 70, at least preventing a decrease in the sealing performance of the insulating member 70 at the deepest compressed end faces 717 and 727. In particular, the extension direction of the delamination region 79 is the same as the laminar flow direction. If the inlet 74 and the end faces 717 and 727 of the insulation 70 that are compressed to the deepest point overlap in the axial direction A, a delamination region 79 parallel to the riveting force direction of the insulation 70 will be generated. This can easily crush the insulation 70 at the riveting force position, resulting in poor sealing and potentially causing contact between the electrode terminal 40 and the end wall 14, thus failing to provide the most basic insulation effect. The embodiments of this application can avoid the generation of a delamination region 79 parallel to the riveting direction at the end faces 717 and 727 of the insulation 70 that are compressed to the deepest point, thereby improving the safety of the secondary battery 100.

[0093] See Figure 9 The insulating member 70 has a through hole for the through portion 44 to pass through. Along the radial direction of the insulating member 70, the minimum distance between points 719 and 729 and the glue inlet 74 is Y mm (i.e., the minimum distance between the end faces 717 and 727 of the compressed portions 715 and 725 of the insulating member 70 in a compressed state, where the riveting portion compresses the deepest, and the glue inlet 74 is Y mm). See, for example, [reference needed]. Figure 14 The difference between the maximum outer diameter D of the insulating component 70 and the minimum diameter d of the through hole (i.e., the minimum diameter of the insulating component 70, measured at the portion along the radial R of the through hole aligned with the through part 44) is Z mm, and 0.3≤Y / Z≤0.8. The distance between the deepest compressed end faces 717 and 727 of the compression portions 715 and 725 and the inlet 74 is controlled within a suitable range to make the path of plastic molten slurry injection and flow more suitable, avoid excessive occurrence of delamination areas 79 at the pressure positions of the insulating component 70, and improve the sealing performance of the insulating component 70 at the compressed positions. Furthermore, in the axial direction A, points 719 and 729 do not overlap with the delamination area 79. That is, the end faces 717 and 727 of the compression portions 715 and 725 that are compressed to the deepest point do not overlap with the delamination area 79. The lower plastic 70 has the greatest compression ratio at these end faces 717 and 727. By designing the distance between the end faces 717 and 727 and the inlet 74, the delamination area 79 does not overlap with these end faces 717 and 727 in the axial direction A. This avoids affecting the sealing performance of the pressure-bearing position due to the presence of the delamination area 79 and improves the sealing effect of the insulating component 70.

[0094] The insulating element 70 in this application embodiment (e.g., the second insulating element 72 in the first embodiment and / or the first insulating element 71 in the second embodiment) uses a material with a melt flow index greater than or equal to 9 g / 10 min, which is relatively high (e.g., compared to PP material), thus easily generating delamination regions 79. This application embodiment provides an insulating element 70 that reduces delamination regions 79, thereby improving the sealing performance of the insulating element 70 itself, and consequently improving the sealing performance of the secondary battery 100. In this application embodiment, the insulating element 70 includes N glue inlets 74, which are spaced apart along the circumferential direction C of the insulating element 70, where N ≥ 2. Compared to an embodiment with only one glue inlet 74, the material flow path in the circumferential direction C is reduced. The longer the material flow path, the faster the flow velocity of the central flow layer compared to the areas near the side edges on the flow channel cross-section, and the more severe the delamination phenomenon of the insulating element 70. By increasing the number of inlets 74, the flow rate difference during material flow is reduced, thereby reducing the delamination area 79 at least on the circumferential C of the insulating member 70. This reduces the penetration of external substances (such as water molecules) into the interior of the secondary battery 100 through the body of the insulating member 70, thereby improving the sealing performance of the insulating member 70 itself.

[0095] N injection ports 74 are disposed on the same surface 77 of the insulating member 70 (second insulating member 72) perpendicular to the axial direction A of the secondary battery 100, and are equidistantly distributed along the circumferential direction C of the second insulating member 72. In an embodiment with three injection ports 74, the angle between the line connecting every two injection ports 74 and the center of the insulating member 70 is 120°. With N injection ports 74 disposed on the same surface 77, i.e., at the same height along the axial direction A, the material flow along the axial direction A tends to be consistent. During the injection molding process of the insulating member 70, the injection mold is preferably horizontal, i.e., the axial direction A is vertical. The N injection ports 74 are disposed on the same plane perpendicular to the axial direction A, i.e., on the same horizontal plane, avoiding height differences between the injection ports 74 and improving the consistency of material flow rate along the circumferential direction C. Furthermore, the equidistant distribution of N injection ports 74 along the circumferential direction C avoids further increasing the flow rate difference due to different injection port spacing. The embodiments of this application improve the consistency of the seal of the insulating element 70 in the circumferential direction C.

[0096] See Figures 24 to 30 The first fixing part 41 is located inside the housing 10 and is the riveting part of the electrode terminal 40. The first insulating member 71 has an intermediate part 716 between the end wall 14 and the first fixing part 41. The intermediate part 716 is a compression part 715 and has a compressed curved surface when it overlaps with the orthographic projection of the end wall 14 and the first fixing part 41 along the axial direction A. The first insulating member 71 also includes a first extension 714 located between the through part 44 and the end wall 14, and a second extension 712 located outside the intermediate part 716 of the first insulating member 71. The glue inlet 74 is located on the second extension 712 and is radially away from the outer wall of the compression part 715. The first insulating member 71 is pressed by the first fixing part 41 and the end wall 14 to provide a seal between the first fixing part 41 and the end wall 14. The glue inlet 74 is located on the outer side wall of the second extension 712 to be as far away from the compression part 715 as possible, so that more of the layered region 79 in the first insulating member 71 (at the glue inlet 74) is farther away from the compression part 715, thereby improving the sealing performance of the compression part 715.

[0097] See Figure 24The insulating member 70 also includes a third insulating member 73 for insulating the current collector 141 and the end wall 14. The third insulating member 73 surrounds the first insulating member 71. The second extension 712 overlaps with the orthographic projection of the third insulating member 73 in the axial direction A, and the second extension 712 is fixed to the third insulating member 73 in the axial direction A. The inner ring of the third insulating member 73, which is radially R close to the mounting hole, rests on the second extension 712 to limit the displacement of the third insulating member 73 in the axial direction A. The height difference in the axial direction A between the surface of the second extension 712 facing the electrode assembly 120 and the surface of the compression portion 715 of the first insulating member 71 facing the electrode assembly 120 is W mm, and the thickness of the second extension 712 is X mm, where W < 0.5 × X. When the molten plastic slurry flows over the step, it encounters resistance, increasing the difference in laminar flow velocity and creating more delamination zones 79. Controlling the height difference W within a reasonable range reduces the step height, minimizes the laminar flow velocity difference, and improves the delamination phenomenon, ensuring both the fixation of the first insulating component 71 and a good seal. The third insulating component 73 is not compressed and is farther from the welding position of the electrode terminal 40 (compared to the second insulating component 72), therefore, PP material can be selected to reduce costs.

[0098] The secondary battery 100 in this application embodiment is, for example, a cylindrical battery. The casing 10 is made of nickel-coated steel, and the surface of the nickel-coated steel has a nickel coating, which is mainly used to prevent the electrolyte from corroding the nickel-coated steel. Using nickel-coated steel as the casing of a cylindrical battery requires higher sealing performance. If the sealing is poor, water will enter the cylindrical battery and react with the electrolyte to produce hydrogen ions. These hydrogen ions will react with the nickel coating of the nickel-coated steel, corroding the casing 10 and generating nickel ions. These nickel ions will then integrate into / enter the electrode assembly 120, forming nickel metal, which may cause a short circuit between the positive electrode 121 and the negative electrode 123 of the electrode assembly 120, affecting the safety of the cylindrical battery. This application embodiment avoids the above-mentioned technical problems and improves the safety of the secondary battery 100 by improving the sealing performance of the insulating member 70 at the interface between the compression portions 715 and 725 and the electrode terminals 40 and end walls 14, as well as improving the sealing performance of the compression portions 715 and 715 themselves.

[0099] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A secondary battery, characterized in that, include: A housing having an opening at one axial end and an end wall at the opposite end, the end wall having a mounting hole; Electrode assembly, disposed within the housing; An electrode terminal is fixed to the end wall and electrically connected to the electrode assembly. The electrode terminal includes a through portion that passes through the mounting hole, and a first fixing portion and a second fixing portion disposed on both sides of the end wall in the axial direction. An insulating member surrounding the through portion includes a first insulating member disposed between the end wall and the first fixing portion and a second insulating member disposed between the end wall and the second fixing portion; wherein the first fixing portion is a riveting portion of the electrode terminal, a portion of the first insulating member forms a compressed portion in a compressed state between the end wall and the first fixing portion, and / or, the second fixing portion is a riveting portion of the electrode terminal, a portion of the second insulating member forms a compressed portion in a compressed state between the end wall and the second fixing portion; The insulating component includes an inlet, and the contact surface where the compression part contacts the riveting part is a compressed curved surface. In a cross-sectional view passing through the axis of the insulating component, the contact surface has a point that is compressed to the deepest point, and the point does not overlap with the orthographic projection of the inlet in the axial direction.

2. The secondary battery according to claim 1, characterized in that, The insulating member has a through hole through which the through part passes. The minimum distance between the point and the glue inlet along the radial direction of the insulating member is Y mm. The difference between the maximum outer diameter of the insulating member and the minimum diameter of the through hole is Z mm, and 0.3≤Y / Z≤0.

8.

3. The secondary battery according to claim 2, characterized in that, The insulating element has a layered region, and the point does not overlap with the layered region in the axial direction.

4. The secondary battery according to claim 1, characterized in that, The second fixing part is located outside the housing, and the second insulating member further includes an outer edge portion surrounding the outer periphery of the second fixing part, and an inner edge portion located between the through portion and the end wall. The glue inlet is located within the orthogonal projection range of the outer edge in the axial direction, and is located on the side of the outer edge facing the end wall.

5. The secondary battery according to claim 4, characterized in that, The second fixing part is the riveting part of the electrode terminal. The electrode terminal includes a terminal body and a sealing pin. The terminal body has a hollow portion on the side opposite to the electrode assembly. The sealing pin is welded to the terminal body and seals the hollow portion. The terminal body is welded to a current collector at the bottom of the hollow portion. The electrode terminal is electrically connected to the electrode assembly through the current collector. The second insulating component is made of soluble polytetrafluoroethylene.

6. The secondary battery according to claim 5, characterized in that, The number of glue inlets is N, where N≥2. The N glue inlets are arranged on the same surface perpendicular to the axial direction and are equidistantly distributed along the circumference of the second insulating member.

7. The secondary battery according to claim 1, characterized in that, The first fixing part is located inside the housing and is the riveting part for the electrode terminal. The first insulating member further includes a first extension located between the through portion and the end wall, and a second extension located outside the compression portion of the first insulating member. The first insulating member includes an adhesive inlet located on the outer wall of the second extension away from the compression portion.

8. The secondary battery according to claim 7, characterized in that, The first insulating component is made of soluble polytetrafluoroethylene. The secondary battery further includes a current collector connected between the electrode terminals and the electrode assembly. The insulating component further includes a third insulating component for insulating the current collector and the end wall. The third insulating component surrounds the first insulating component, and the second extension is fixed to the third insulating component in the axial direction of the housing. The height difference in the axial direction between the surface of the second extension facing the electrode assembly and the surface of the compression portion of the first insulator facing the electrode assembly is W mm, and the thickness of the second extension is X mm, where W < 0.5 × X.

9. A battery pack, characterized in that, Includes the secondary battery as described in any one of claims 1 to 8.

10. An electrical appliance, characterized in that, Includes the battery pack as described in claim 9.

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