Cover plate assembly and single battery

Abstract

The invention relates to the technical field of batteries, in particular to a cover plate assembly and a single battery. The cover plate assembly comprises a cover plate, an electrode terminal, a pressing plate and a first insulating part, and the electrode terminal penetrates through the cover plate in the thickness direction of the cover plate; the pressing plate is arranged on the outer side of the cover plate and connected with the electrode terminal, and the projection of the pressing plate at least partially coincides with the projection of the cover plate in the thickness direction of the cover plate; at least part of the first insulating part is arranged between the pressing plate and the cover plate; one of the radial outer peripheral surface of the electrode terminal and the radial inner peripheral surface of the pressing plate is provided with a first convex part, the other of the radial outer peripheral surface of the electrode terminal and the radial inner peripheral surface of the pressing plate is welded to the first convex part, and the other of the radial outer peripheral surface of the electrode terminal and the radial inner peripheral surface of the pressing plate is provided with a second convex part. In the thickness direction of the cover plate, the first protruding part is located on the outer side of the second protruding part, and at least part of the projection of the first protruding part overlaps with the projection of the second protruding part. And the heating damage of the insulating part caused by welding heat is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a cover plate assembly and a single cell. Background Art

[0002] In the related technology, the cover plate assembly includes a cover plate body, a pressure plate and an electrode terminal. The electrode terminal is welded to the pressure plate. During the welding process of the electrode terminal and the pressure plate, the welding heat is relatively high, causing the insulating part between the pressure plate and the cover plate body to soften due to the heat, thereby causing insulation failure and affecting the battery performance. Summary of the invention

[0003] The present application provides a cover plate assembly and a single cell battery, which solves the technical problem that the heat from welding the pressure plate and the electrode terminal causes the insulating part to soften due to heat and cause insulation failure, thereby reducing the thermal damage to the insulating part caused by the welding heat and improving the reliability of the battery.

[0004] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0005] In a first aspect, an embodiment of the present application provides a cover plate assembly, comprising a cover plate, an electrode terminal, a pressure plate and a first insulating member, wherein the electrode terminal penetrates the cover plate along the thickness direction of the cover plate; the pressure plate is arranged on the outer side of the cover plate, the pressure plate is connected to the electrode terminal, and along the thickness direction of the cover plate, the projection of the pressure plate at least partially overlaps with the projection of the cover plate; at least a portion of the first insulating member is arranged between the pressure plate and the cover plate, and the first insulating member has a first radial inner circumferential surface abutting against the electrode terminal; wherein a first convex portion is arranged on one of the radial outer circumferential surface of the electrode terminal and the radial inner circumferential surface of the pressure plate, the other of the radial outer circumferential surface of the electrode terminal and the radial inner circumferential surface of the pressure plate is welded with the first convex portion to form a first weld, and a second convex portion is arranged on the radial outer circumferential surface of the electrode terminal and the other of the radial inner circumferential surface of the pressure plate, along the thickness direction of the cover plate, the first convex portion is located on the outer side of the second convex portion, at least a portion of the projection of the first convex portion overlaps with the projection of the second convex portion, and the projection of the first weld does not overlap with the projection of the first radial inner circumferential surface.

[0006] In the cover plate assembly proposed in the embodiment of the present application, the electrode terminal passes through the cover plate and is connected to the pressure plate. One of the radial outer peripheral surface of the electrode terminal and the radial inner peripheral surface of the pressure plate is provided with a first convex portion, and the other is provided with a second convex portion. The first convex portion is covered on the outside of the second convex portion. The electrode terminal passes through the cover plate and is connected to the pressure plate through the first convex portion to achieve the fixation of the electrode terminal. Among them, the electrode terminal and the pressure plate are welded through the first convex portion to form a first weld. Along the thickness direction of the cover plate, at least part of the projection of the first convex portion overlaps with the projection of the second convex portion. When the electrode terminal and the pressure plate are welded, the welding heat is blocked by the second convex portion, reducing the heat transferred to the first insulating member when the electrode terminal and the pressure plate are welded; at the same time, along the thickness direction of the cover plate, the projection of the first weld does not overlap with the projection of the first radial inner peripheral surface, reducing the welding heat transferred to the first insulating member when the pressure plate and the electrode terminal are welded through the first convex portion, thereby reducing the probability of damage to the first insulating member.

[0007] In the second aspect, an embodiment of the present application provides a single cell battery, comprising a shell, an electrode assembly, a diaphragm and a cover assembly as described in any of the above embodiments, wherein the cover assembly is connected to the shell to form a accommodating chamber; the electrode assembly is arranged in the accommodating chamber, the electrode assembly comprises an electrode assembly body and a pole ear, and the pole ear is respectively connected to the electrode assembly body and the electrode terminal; the diaphragm is arranged on the outside of the electrode assembly body, and the pole ear is connected to the electrode assembly body through the diaphragm.

[0008] In the single battery cell proposed in the embodiment of the present application, the electrode terminal and the pressure plate are connected through the connection circumference of the first protrusion, and there is a second protrusion on the inner side of the connection between the electrode terminal and the pressure plate along the thickness direction of the cover plate. When the electrode terminal and the pressure plate are welded on the first circumference, the welding heat is blocked by the second protrusion, reducing the heat transferred to the first insulating member when the electrode terminal and the pressure plate are welded, thereby reducing the probability of damage to the first insulating member, thereby achieving the purpose of improving the reliability of the battery. At the same time, the second protrusion can also reduce the heat transferred to the diaphragm when the electrode terminal and the pressure plate are welded, thereby alleviating the problem of diaphragm shrinkage. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0010] Figure 1 This is a schematic cross-sectional structure diagram of a cover plate assembly according to an embodiment of the present application;

[0011] Figure 2 for Figure 1Enlarged view of area B;

[0012] Figure 3 This is a schematic cross-sectional structural diagram of a cover plate assembly according to another embodiment of the present application;

[0013] Figure 4 for Figure 3 Enlarged view of the middle C area;

[0014] Figure 5 Schematic diagram of the structure of a single battery.

[0015] [Description of Reference Numerals]

[0016] 1: Cover plate;

[0017] 2: electrode terminal; 21: first connecting portion; 22: main body; 23: first main body section; 24: second main body section; 25: first step surface; 26: first section; 27: second section; 28: connection interface;

[0018] 3: pressing plate; 31: second connecting portion;

[0019] 4: first insulating member; 40: first mounting hole; 41: first portion; 42: second portion; 43: first radial inner peripheral surface;

[0020] 5: first convex portion; 51: first outer end surface; 52: second outer end surface; 53: connecting peripheral surface; 54: first weld;

[0021] 6: The second convex part;

[0022] 71: electrode assembly; 72: diaphragm; 73: tab;

[0023] A: Thickness direction of the cover plate. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0026] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0029] The term "multiple" as used in the present application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0030] In the related technology, the cover plate assembly includes a cover plate body, a pressure plate and an electrode terminal. The electrode terminal is welded to the pressure plate. During the welding process of the electrode terminal and the pressure plate, the welding heat is relatively high and the laser is prone to light leakage, which causes the insulating part between the pressure plate and the cover plate body to soften due to heat, thereby causing insulation failure and affecting the battery performance.

[0031] In view of this, in order to reduce the failure of insulating components and improve the reliability of batteries, the present application embodiment provides a cover plate assembly. Figures 1 to 4The cover plate assembly includes a cover plate 1, an electrode terminal 2, a pressing plate 3 and a first insulating member 4.

[0032] The electrode terminal 2 penetrates the cover plate 1 along the thickness direction A of the cover plate; the pressing plate 3 is arranged on the outer side of the cover plate 1, and the pressing plate 3 is connected to the electrode terminal 2. Along the thickness direction A of the cover plate, the projection of the pressing plate 3 at least partially overlaps with the projection of the cover plate 1; at least part of the first insulating member 4 is arranged between the pressing plate 3 and the cover plate 1, and the first insulating member 4 has a first radial inner circumferential surface 43 abutting against the electrode terminal 2; wherein, a first convex portion 5 is arranged on one of the radial outer circumferential surface of the electrode terminal 2 and the radial inner circumferential surface of the pressing plate 3, and the other of the radial outer circumferential surface of the electrode terminal 2 and the radial inner circumferential surface of the pressing plate 3 is welded with the first convex portion 5 to form a first weld 54, and a second convex portion 6 is arranged on the radial outer circumferential surface of the electrode terminal 2 and the other of the radial inner circumferential surface of the pressing plate 3, along the thickness direction A of the cover plate, the first convex portion 5 is located on the outer side of the second convex portion 6, at least part of the projection of the first convex portion 5 overlaps with the projection of the second convex portion 6, and the projection of the first weld 54 does not overlap with the projection of the first radial inner circumferential surface 43.

[0033] In the cover plate assembly proposed in the embodiment of the present application, the electrode terminal 2 passes through the cover plate 1 and is connected to the pressing plate 3. One of the radial outer peripheral surface of the electrode terminal 2 and the radial inner peripheral surface of the pressing plate 3 is provided with a first convex portion 5, and the other is provided with a second convex portion 6. The first convex portion 5 is covered on the outside of the second convex portion 6. The electrode terminal 2 passes through the cover plate 1 and is connected to the pressing plate 3 through the first convex portion 5 to achieve the fixation of the electrode terminal 2. The electrode terminal 2 and the pressing plate 3 are welded through the first convex portion 5 to form a first weld 54, wherein the connection between the electrode terminal 2 and the pressing plate 3 through the first convex portion 5 extends along the thickness direction A of the cover plate. Along the thickness direction A of the cover plate, at least part of the projection of the first protrusion 5 overlaps with the projection of the second protrusion 6, that is, there is a second protrusion 6 on the inner side of the connection between the electrode terminal 2 and the pressure plate 3. When the electrode terminal 2 and the pressure plate 3 are welded, the welding heat is blocked by the second protrusion 6, thereby reducing the heat transferred to the first insulating member 4 when the electrode terminal 2 and the pressure plate 3 are welded; at the same time, along the thickness direction A of the cover plate, the projection of the first weld 54 does not overlap with the projection of the first radial inner circumferential surface 43, thereby reducing the welding heat transferred to the first insulating member 4 when the pressure plate 3 and the electrode terminal 2 are welded through the first protrusion 5, thereby reducing the probability of damage to the first insulating member 4.

[0034] Among them, along the thickness direction A of the cover plate, the side facing the pressing plate 3 is the outer side, and the side away from the pressing plate 3 is the inner side. The electrode terminal 2 passes through the cover plate 1 from the inner side of the cover plate 1 and extends to the outer side of the cover plate 1. The pressing plate 3 is arranged on the outer side of the cover plate 1, and at the first convex portion 5, the electrode terminal 2 and the pressing plate 3 are welded to form a first weld 54, and the first weld 54 has a second convex portion 6 on the inner side along the thickness direction of the cover plate 1. When the electrode terminal 2 and the pressing plate 3 are welded, the second convex portion 6 protects the first insulating member 4 to reduce the damage caused by the welding heat to the first insulating member 4.

[0035] At the same time, since the projection of the first weld 54 does not overlap with the projection of the first radial inner peripheral surface 43 along the thickness direction A of the cover plate, the heat of the first weld 54 cannot be directly transferred to the first insulating member 4, thereby reducing the probability of heat damage to the first insulating member 4.

[0036] Specifically, when the first convex portion 5 is provided on the pressing plate 3, the second convex portion 6 is provided on the electrode terminal 2, and the electrode terminal 2 has an electrode terminal 2 step that matches the first convex portion 5, and the electrode terminal 2 step has a surface perpendicular to the thickness direction of the cover plate 1 and a surface parallel to the thickness direction of the cover plate 1, and the second convex portion 6 and the electrode terminal 2 step share a surface perpendicular to the thickness direction of the cover plate 1. The welding surfaces of the pressing plate 3 and the electrode terminal 2 are the radial inner peripheral surface of the first convex portion 5 and the surface of the electrode terminal 2 step parallel to the thickness direction of the cover plate 1.

[0037] When the first convex portion 5 is provided on the electrode terminal 2, the second convex portion 6 is provided on the pressing plate 3, and the pressing plate 3 has a pressing plate 3 step that matches the first convex portion 5. The pressing plate 3 step has a surface perpendicular to the thickness direction of the cover plate 1 and a surface parallel to the thickness direction of the cover plate 1, and the second convex portion 6 and the pressing plate 3 step share a surface perpendicular to the thickness direction of the cover plate 1. The welding surface of the pressing plate 3 and the electrode terminal 2 is the surface of the first convex portion 5 and the pressing plate 3 step parallel to the thickness direction of the cover plate 1.

[0038] It should be understood that if the first protrusion 5 is provided on the pressure plate 3, the first protrusion 5 and the pressure plate 3 are an integral structure, and the first protrusion 5 is formed on the outside of the pressure plate 3 along the thickness direction of the cover plate 1 by cutting off a piece of the radial inner surface of the pressure plate 3 along the inner side of the thickness direction of the cover plate 1; and the second protrusion 6 on the electrode terminal 2 is formed by cutting a piece of the radial outer surface of the electrode terminal 2 inwardly to form the second protrusion 6, so that the first protrusion 5 can overlap the second protrusion 6.

[0039] If the first protrusion 5 is provided on the electrode terminal 2, the first protrusion 5 and the electrode terminal 2 are an integral structure, and the first protrusion 5 protrudes from the radial outer surface of the electrode terminal 2; the second protrusion 6 and the pressing plate 3 are an integral structure, and a piece is cut off from the radial inner surface of the pressing plate 3 along the outer side of the thickness direction of the cover plate 1, and the second protrusion 6 is formed on the inner side of the pressing plate 3 along the thickness direction of the cover plate 1, so that the first protrusion 5 can overlap the second protrusion 6.

[0040] Optionally, refer to Figure 2 , the size h of the first protrusion 5 and the size H of the pressure plate 3 satisfy: 0.15≤h / H≤0.9. The size h of the first protrusion 5 along the thickness direction of the cover plate 1 is h, and the size H of the pressure plate 3 along the thickness direction is H. The size h of the first protrusion 5 along the thickness direction of the cover plate 1 cannot be too small. If the size h of the first protrusion 5 along the thickness direction of the cover plate 1 is too small, relatively speaking, the size H of the pressure plate 3 is larger, which will cause the welding fixation between the pressure plate 3 and the electrode terminal 2 to be loose, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, thereby causing the sealing failure of the cover assembly and being unfavorable for overcurrent; if the size h of the first protrusion 5 along the thickness direction of the cover plate 1 is too large, the welding area where the pressure plate 3 and the electrode terminal 2 are connected will be too close to the first insulating member 4, and the welding temperature will easily cause the first insulating member 4 to soften, thereby causing the insulation failure of the first insulating member 4.

[0041] Therefore, the ratio h / H of the size h of the first protrusion 5 and the size H of the pressing plate 3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8. While ensuring the connection strength and current capacity between the motor terminal and the pressing plate 3, the damage to the first insulating member 4 during welding of the electrode terminal 2 and the pressing plate 3 is reduced, and the sealing stability of the cover assembly is improved.

[0042] Optionally, refer to Figure 2 , along the thickness direction A of the cover plate, the size of the first protrusion 5 is h, and the size of the pressure plate 3 is H, which satisfies: 0.5mm≤h≤2mm, 1.5mm≤H≤3mm. The size of the first protrusion 5 along the thickness direction of the cover plate 1 is h, and the size h of the first protrusion 5 along the thickness direction of the cover plate 1 cannot be too small. If the size h of the first protrusion 5 along the thickness direction of the cover plate 1 is too small, the welding fixation between the pressure plate 3 and the electrode terminal 2 will be loose, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, thereby causing the sealing failure of the cover plate assembly and being unfavorable for overcurrent; if the size h of the first protrusion 5 along the thickness direction of the cover plate 1 is too large, the welding area where the pressure plate 3 and the electrode terminal 2 are connected will be too close to the first insulating member 4, and the welding temperature will easily cause the first insulating member 4 to soften, thereby causing the insulation failure of the first insulating member 4.

[0043] Along the thickness direction A of the cover plate, the dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 can be 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm or 1.8 mm. Thus, while ensuring the connection strength and current capacity between the motor terminal and the pressing plate 3, the damage to the first insulating member 4 during welding of the electrode terminal 2 and the pressing plate 3 is reduced.

[0044] Along the thickness direction A of the cover plate, the dimension of the pressing plate 3 along the thickness direction is H. If the dimension H of the pressing plate 3 is too small, the welding fixation between the pressing plate 3 and the electrode terminal 2 will be loose, affecting the connection strength between the electrode terminal 2 and the pressing plate 3, thereby causing the sealing failure of the cover plate 1 and being unfavorable for current flow; if the dimension H of the pressing plate 3 is too large, the pressing plate 3 requires a large bearing capacity, and the bearing capacity of the cover plate assembly is insufficient to support the pressing plate 3, which will cause the sealing failure of the cover plate 1.

[0045] Along the thickness direction A of the cover plate, the size H of the pressing plate 3 can be 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm or 2.8 mm. Thus, the size of the pressing plate 3 is ensured to be appropriate, the cover plate assembly has sufficient bearing capacity for it, and the connection strength between the electrode terminal 2 and the pressing plate 3 is improved, and the sealing stability of the cover plate assembly is improved.

[0046] Optionally, refer to Figure 2 , along the thickness direction A of the cover plate, the size of the first weld 54 is h 1 , the size of the first protrusion 5 is h, satisfying: h 1 <h. The first protrusion 5 has a first outer end face 51, a second outer end face 52, and a connecting circumferential surface 53 connecting the first outer end face 51 and the second outer end face 52, and the connecting circumferential surface 53 is parallel to the thickness direction A of the cover plate; the connecting circumferential surface 53 has a first welding area, and the connecting surface where the electrode terminal 2 and the pressure plate 3 are connected is the connecting circumferential surface 53 of the first protrusion 5. The electrode terminal 2 and the pressure plate 3 are welded at the connecting circumferential surface 53 to form a first weld 54, and the first weld 54 extends along the thickness direction of the cover plate 1. The size of the first weld 54 h 1 and the dimension h of the first protrusion 5 satisfies: h 1 <h. That is to say, when the size of the first weld 54 is constant, the size of the first protrusion 5 along the thickness direction of the cover plate 1 needs to be high enough to accommodate the first weld 54, so as to reduce the laser leakage during the laser welding of the pressing plate 3 and the electrode terminal 2, resulting in the laser hitting the first insulating member 4, thereby reducing the softening of the first insulating member 4 due to heat, and further reducing the insulation failure of the first insulating member 4.

[0047] Optionally, the size h of the first weld 54 is 1 Satisfies: 0.5 mm ≤ h ≤ 2 mm, and the size h of the first protrusion 5 satisfies: 0.5 mm ≤ h 1 ≤2mm. The size h of the first weld 541 The size of the first protrusion 5 along the thickness direction of the cover plate 1 is h, and the size h of the first protrusion 5 can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm or 1.8mm.

[0048] Optionally, 0≤hh 1 ≤1.5mm. Along the thickness direction A of the cover plate, the difference between the size of the first protrusion 5 and the size of the first weld 54 cannot be too small. If the size difference is too small, laser light leakage is easy to occur during laser welding of the pressing plate 3 and the electrode terminal 2, causing the laser to hit the first insulating member 4, resulting in heat damage to the first insulating member 4, and further causing insulation failure of the first insulating member 4. The size of the first protrusion 5 along the thickness direction of the cover plate 1 and the size of the first weld 54 along the thickness direction of the cover plate 1 cannot be too large. If the size difference is too large, it means that the size of the first weld 54 is too small, which will result in a weak welding strength between the pressing plate 3 and the electrode terminal 2, and further cause sealing failure of the cover plate 1.

[0049] Along the thickness direction A of the cover plate, the dimension h of the first protrusion 5 and the dimension h of the first welding area are 1 The difference can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm or 1.4mm.

[0050] Optionally, refer to Figure 1 and Figure 2 , the first protrusion 5 is arranged on the radial inner circumference of the pressure plate 3, and the first protrusion 5 is welded and fixed to the radial outer circumference of the electrode terminal 2. The first protrusion 5 is arranged on the radial inner circumference of the pressure plate 3, and the second protrusion 6 is arranged on the radial outer circumference of the electrode terminal 2, that is, the second protrusion 6 protrudes from the radial outer circumference of the electrode terminal 2, and a step of the electrode terminal 2 is formed on the outer side of the second protrusion 6, and the first protrusion 5 overlaps the step of the electrode terminal 2. The first protrusion 5 has a connecting circumferential surface 53 parallel to the thickness direction A of the cover plate, and the connecting circumferential surface 53 of the first protrusion 5 is welded and fixed to the radial outer circumference of the electrode terminal 2 at the step of the electrode terminal 2. When the electrode terminal 2 and the pressure plate 3 are welded, the heat of welding is blocked by the second protrusion 6, which reduces the heat of welding the electrode terminal 2 and the pressure plate 3 from being transferred to the first insulating member 4, thereby reducing the damage of the first insulating member 4.

[0051] Optionally, refer to Figure 1 and Figure 2 , along the thickness direction A of the cover plate, the outer end of the electrode terminal 2 protrudes from the outer end of the pressing plate 3 to form a first connecting portion 21, and the first connecting portion 21 is connected to the busbar; along the radial direction of the electrode terminal 2, the width of the first protrusion 5 is W 1 , the diameter of the first connecting portion 21 is D1 , satisfying: 0.0125≤W 1 / D 1 ≤0.2.

[0052] Specifically, the first protrusion 5 is provided on the pressure plate 3, the second protrusion 6 is provided on the electrode terminal 2, the second protrusion 6 has a step of the electrode terminal 2 on the outer side along the thickness direction A of the cover plate, the first protrusion 5 is overlapped on the step of the electrode terminal 2 and welded with the step of the electrode terminal 2 at the connection circumferential surface 53. The electrode terminal 2 is provided with a first connecting portion 21 on the outer side along the thickness direction of the cover plate 1, the first connecting portion 21 protrudes from the outer ends of the pressure plate 3 and the first protrusion 5, and is connected to the busbar. In the radial direction of the electrode terminal 2, the width of the first protrusion 5 is W 1 , that is, the width of the step of the electrode terminal 2 along the radial direction of the electrode terminal 2 is W 1 , the diameter of the first connecting portion 21 is D 1 , satisfy: 0.0125≤W 1 / D 1 ≤0.2.

[0053] Since the electrode terminal 2 is stepped on the electrode terminal 2, the diameter of the electrode terminal 2 and the diameter of the first connecting portion 21 are reduced relative to the diameter of the second protrusion 6. The first connecting portion 21 on the surface of the electrode terminal 2 is welded to the busbar. If the diameter D of the first connecting portion 21 is 1 If it decreases, the surface area of ​​the first connection portion 21 will be small, and the welding area with the busbar will be reduced, which will further affect the current carrying capacity of the electrode terminal 2 and the first connection portion 21.

[0054] The width W of the first protrusion 5 1 Too wide will affect the current carrying capacity of the electrode terminal 2; the width W of the first protrusion 5 1 If the width W of the first protrusion 5 is too narrow, it will cause the electrode terminal 2 and the pressing plate 3 to be difficult to weld and the welding strength is insufficient. 1 It is too narrow, and the projection of the welding surface of the electrode terminal 2 and the pressure plate 3 on the cover plate 1 is close to the projection of the connection between the second protrusion 6 and the pressure plate 3. When the electrode terminal 2 and the pressure plate 3 are welded, the welding laser will leak light to the inside, which will cause the welding heat to affect the first insulating part 4, causing the first insulating part 4 to be damaged by heat.

[0055] Therefore, in order to ensure the current carrying capacity of the first connecting portion 21 and reduce the damage of the first insulating member 4, the following conditions should be met: 0.0125≤W 1 / D 1 ≤0.2. The width W of the first protrusion 5 1 The diameter D of the first connecting portion 21 1 The ratio W 1 / D 1It can be 0.02, 0.03, 0.04, 0.05, 0.08, 0.1, 0.14, 0.16 or 0.18.

[0056] Optionally, the width W of the first protrusion 5 is 1 Satisfy: 0.5mm≤W 1 ≤2mm, the diameter D of the first connecting portion 21 1 Satisfy: 10mm≤D 1 ≤40mm. The diameter D of the first connecting portion 21 1 The width W of the first protrusion 5 can be 15 mm, 20 mm, 25 mm, 30 mm, 35 mm or 38 mm. 1 It can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm or 1.8mm.

[0057] It should be understood that when the first protrusion 5 is provided on the pressure plate 3, if the electrode terminal 2 is connected to the bus, the outer side of the electrode terminal 2 has a first connecting portion 21, and the first connecting portion 21 protrudes from the outer side of the first protrusion 5 and the pressure plate 3. At this time, the outer surface of the first protrusion 5 can be flat or uneven.

[0058] Optionally, refer to Figure 1 The electrode terminal 2 has a main body 22 that is interference-fitted with the first radial inner peripheral surface 43. The outer ends of the pressing plate 3 and the first protrusion 5 both protrude from the outer ends of the electrode terminal 2 to form a second connecting portion 31, which is connected to the busbar. Along the radial direction of the electrode terminal 2, the width of the second connecting portion 31 is W. 2 , the diameter of the main body 22 is D 2 , satisfying: 0.05≤W 2 / D 2 ≤0.8.

[0059] The first insulating member 4 has a first mounting hole 40, and the radial inner surface of the first mounting hole is a first radial inner circumferential surface 43. The first insulating member 4 is sleeved on the radial outer side of the electrode terminal 2, and the first radial inner circumferential surface 43 of the first insulating member 4 is interference fit with the electrode terminal 2. The first insulating member 4 plays the role of sealing and insulation at the same time. The outer end of the pressing plate 3 and the outer end of the first protrusion 5 both protrude from the outer end of the electrode terminal 2 to form a second connecting portion 31, and the second connecting portion 31 is connected to the bus. Along the radial direction of the electrode terminal 2, the width of the second connecting portion 31 is the sum of the width of the pressing plate 3 and the width of the first protrusion 5. Since the connection between the second connecting portion 31 and the bus requires the control of the current capacity of the second connecting portion 31, if the width W of the second connecting portion 31 along the radial direction of the electrode terminal 2 2 If the value is too small, the flow capacity of the second connection portion 31 will be insufficient.

[0060] The width W of the second connection portion 31 2 The diameter D of the main body 22 2 The ratio W 2 / D 2 It can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7, thereby ensuring sufficient current flow capacity.

[0061] Optionally, the width W of the second connecting portion 31 is 2 Satisfy: 2mm≤W 2 ≤8mm, diameter D of the main body 22 2 , meet: 10mm≤D 2 ≤40mm, the width W of the second connecting portion 31 2 The diameter D of the main body 22 of the electrode terminal 2 can be 3 mm, 4 mm, 5 mm, 6 mm or 7 mm, thereby satisfying the current capacity of the second connection portion 31. 2 It can be 15mm, 20mm, 25mm, 30mm, 35mm or 38mm, thereby satisfying the current carrying capacity of the electrode terminal 2.

[0062] It should be understood that, along the thickness direction of the pressing plate 3 , the outer side surface of the pressing plate 3 is flush with the outer side surface of the first protrusion 5 , so as to better connect with the busbar.

[0063] Optionally, refer to Figure 2 , along the thickness direction A of the cover plate, the electrode terminal 2 includes a first main section 23 and a second main section 24, the first main section 23 is located outside the second main section 24; the outer diameter of the first main section 23 is smaller than the outer diameter of the second main section 24 to form a first step surface 25, and the second convex portion 6 is arranged on the second main section 24 and is spaced apart from the first step surface 25 in the thickness direction A of the cover plate. Specifically, along the thickness direction A of the cover plate, the electrode terminal 2 is sequentially the second main section 24 and the first main section 23 from the inside to the outside, the outer diameter of the first main section 23 is smaller than the outer diameter of the second main section 24 to form the first step surface 25, and the first main section 23 is connected to the busbar along the outer side of the thickness direction of the cover plate 1. The second convex portion 6 is arranged on the radial outer side of the second main section 24, and along the radial direction of the electrode terminal 2, the second convex portion 6 protrudes from the second main section 24 to form an electrode terminal 2 step, and the electrode terminal 2 step has an electrode terminal 2 step surface, and along the thickness direction A of the cover plate, the electrode terminal 2 step surface is spaced apart from the first step surface 25. Since the molten pool at the welding point of the electrode terminal 2 and the pressing plate 3 has a second welding area protruding from the outer surface of the first protrusion 5, the second welding area will affect the welding of the busbar and the first main body section 23. In order not to affect the connection between the first main body section 23 and the busbar, the first main body section 23 needs to protrude from the second welding area along the thickness direction A of the cover plate.

[0064] Optionally, refer to Figure 2, along the thickness direction A of the cover plate, the first step surface 25, the outer end surface of the first protrusion 5 and the outer end surface of the pressing plate 3 are flush. The second protrusion 6 is arranged on the radial outer side of the second main body section 24. Along the radial direction of the electrode terminal 2, the second protrusion 6 protrudes from the radial outer surface of the second main body section 24 to form an electrode terminal 2 step, and the electrode terminal 2 step has an electrode terminal 2 step surface. The outer diameter of the first main body section 23 is smaller than the outer diameter of the second main body section 24, so the first step surface 25 is formed at the connection between the first main body section 23 and the second main body section 24. Along the thickness direction A of the cover plate, the electrode terminal 2 step surface is spaced from the first step surface 25. The first protrusion 5 overlaps the step surface of the electrode terminal 2 and is welded to the electrode terminal 2. The first step surface 25, the outer end surface of the first protrusion 5 and the outer end surface of the pressing plate 3 are flush, so as to better control the molten pool of the welding between the pressing plate 3 and the electrode terminal 2, thereby making the connection between the first main body section 23 and the bus bar more reliable.

[0065] Optionally, refer to Figure 1 and Figure 2 The first insulating member 4 includes a first portion 41 and a second portion 42. Along the thickness direction A of the cover plate, the first portion 41 is disposed between the pressing plate 3 and the cover plate 1, and the second portion 42 is connected to the radial outer end of the first portion 41 and covers at least part of the radial outer peripheral surface of the pressing plate 3; along the radial direction of the electrode terminal 2, the distance between the second portion 42 and the radial inner peripheral surface of the first protrusion 5 is d 3 , meet: 2.5mm≤d 3 ≤10mm.

[0066] Specifically, along the thickness direction A of the cover plate, the first portion 41 is disposed between the pressing plate 3 and the cover plate 1, and the second portion 42 is located radially outside the first portion 41 and covers at least a portion of the radial outer peripheral surface of the pressing plate 3. The first portion 41 and the second portion 42 play the role of insulation and sealing between the pressing plate 3 and the cover plate 1. In addition, the second portion 42 covers at least a portion of the radial outer peripheral surface of the pressing plate 3, plays a role in positioning the pressing plate 3, and improves the reliability of the connection between the pressing plate 3 and the electrode terminal 2.

[0067] The welding surface of the electrode terminal 2 and the pressure plate 3 is the radial outer peripheral surface of the first protrusion 5. If the second portion 42 is too close to the radial outer peripheral surface of the first protrusion 5, the heat generated by the laser welding will cause the second portion 42 to be damaged when the electrode terminal 2 and the pressure plate 3 are welded. 3 The thickness may be 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm or 9.5 mm. Thus, it is ensured that the second portion 42 will not be damaged by the heat of laser welding when the electrode terminal 2 and the pressing plate 3 are welded together.

[0068] In a specific embodiment, the first insulating member 4 also includes a third part located radially inside the first part 41, the third part is interference fit with the electrode terminal 2, and the first radial inner circumferential surface 43 on the radial inner side of the third part is configured as a first mounting hole 40, and the third part further seals and insulates the electrode terminal 2 and the cover plate 1.

[0069] Optionally, refer to Figure 3 and Figure 4 , the first protrusion 5 is arranged on the radial outer peripheral surface of the electrode terminal 2, and the first protrusion 5 is welded and fixed to the inner peripheral surface of the pressing plate 3. The first protrusion 5 is arranged on the radial outer peripheral surface of the electrode terminal 2, and the second protrusion 6 is arranged on the radial inner peripheral surface of the pressing plate 3. Along the thickness direction A of the cover plate, the outer side of the second protrusion 6 is formed with a step surface of the pressing plate 3, and the first protrusion 5 overlaps on the step of the pressing plate 3. The first protrusion 5 has a connecting peripheral surface 53 along the thickness direction of the cover plate 1, and the connecting peripheral surface 53 of the first protrusion 5 is welded and fixed to the outer peripheral surface of the pressing plate 3. When the electrode terminal 2 and the pressing plate 3 are welded, the welding heat is blocked by the second protrusion 6, reducing the heat of the welding of the electrode terminal 2 and the pressing plate 3 from being transferred to the first insulating member 4, thereby reducing the damage of the first insulating member 4.

[0070] Among them, the first convex portion 5 is provided on the electrode terminal 2, and the second convex portion 6 is provided on the pressing plate 3. In the thickness direction of the pressing plate 3, a pressing plate 3 step is formed on the outer side of the second convex portion 6, and the first convex portion 5 covers the pressing plate 3 step, and the first convex portion 5 is welded to the pressing plate 3. The first convex portion 5 is provided on the electrode terminal 2, which increases the outer diameter of the electrode terminal 2 at this point and improves the current carrying capacity. In addition, in the manufacturing process of the electrode terminal 2, a circle can be shoveled on the outer periphery of the electrode terminal 2 to form the first convex portion 5, and then the electrode terminal 2 and the pressing plate 3 are butt-welded at the first convex portion 5, which is simple to implement and has a higher structural strength.

[0071] It should be understood that when the first protrusion 5 is arranged on the electrode terminal 2, if the electrode terminal 2 is connected to the bus, the outer side of the electrode terminal 2 has a first connecting portion 21, and the first connecting portion 21 protrudes from the outside of the first protrusion 5 and the pressure plate 3. At this time, the outer surface of the first protrusion 5 can be flat or uneven.

[0072] If the pressing plate 3 is connected to the busbar, the outer end of the pressing plate 3 has a second connecting portion 31 protruding from the first protrusion 5, and the second connecting portion 31 is connected to the busbar. Along the radial direction of the electrode terminal 2, the width of the second connecting portion 31 is W 2 Since the second connection portion 31 is connected to the busbar, the current capacity of the second connection portion 31 needs to be controlled. If the width W of the second connection portion 31 along the radial direction of the electrode terminal 2 is 2If the width of the second connection portion 31 is too small, the current capacity of the second connection portion 31 will be insufficient. Therefore, it is necessary to control the ratio between the width of the second connection portion 31 along the radial direction of the electrode terminal 2 and the diameter D2 of the main body portion 22 of the electrode terminal 2 to satisfy: 0.06≤W 2 / D 2 ≤0.8. In the thickness direction of the pressing plate 3, the outer side surface of the first connecting portion 21 protrudes from the outer side surface of the first protrusion 5 to better connect with the busbar.

[0073] In a specific embodiment, the portion of the electrode terminal 2 located on the inner side of the cover plate 1 has a flange, and the projection of the flange along the thickness direction of the cover plate 1 is at least partially located on the cover plate 1. A second insulating member is provided between the flange and the cover plate 1, and the second insulating member plays a role of sealing and insulation. When the first convex portion 5 is provided on the electrode terminal 2, the first convex portion 5 is located on the outer side of the cover plate 1, and the flange is located on the inner side of the cover plate 1. The cover plate 1 and the first convex portion 5 sandwich the cover plate 1 together, thereby improving the structural strength of the cover plate assembly.

[0074] Optionally, refer to Figure 4 , along the radial direction of the electrode terminal 2, the width of the first protrusion 5 is W 1 The sum of the width of the pressing plate 3 and the width of the second convex portion 6 is W 3 , satisfying: 0.05≤W 1 / W 3 ≤0.8. It should be understood that if the first protrusion 5 is provided on the electrode terminal 2 and the second protrusion 6 is provided on the pressure plate 3, the second protrusion 6 has a step surface of the pressure plate 3 on the outside along the thickness direction of the cover plate 1. In the radial direction of the electrode terminal 2, the width of the step surface of the pressure plate 3 is the same as the width of the first protrusion 5. In the radial direction of the electrode terminal 2, if the width of the first protrusion 5 is too large, the width of the step surface of the pressure plate 3 is also too large, and the width of the pressure plate 3 is reduced, resulting in insufficient structural strength at the step of the pressure plate 3. The root of the step, that is, the connection between the second protrusion 6 and the pressure plate 3, is more likely to break after being affected by the welding heat. If the width of the first protrusion 5 is too small, the welding laser and heat are likely to leak from the connection between the electrode terminal 2 and the pressure plate 3 toward the inside to the first insulating member 4, causing the first insulating member 4 to be damaged by heat, and then causing insulation failure.

[0075] The width W of the first protrusion 5 1 The sum of the width of the pressing plate 3 and the width of the second protrusion 6 is W 3 The ratio W 1 / W 3 It can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7. Thus, the connection between the electrode terminal 2 and the pressing plate 3 is ensured to be stable, and the damage to the first insulating member 4 caused by the heat of welding the electrode terminal 2 and the pressing plate 3 is reduced.

[0076] Optionally, the width W of the first protrusion 5 is 1Satisfy: 0.5mm≤W 1 ≤2mm, the sum of the width of the pressing plate and the width of the second convex part W 3 Meet: 2.5mm≤W 3 ≤10mm. The width W of the first protrusion 5 1 It can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm or 1.8mm.

[0077] The sum of the width of the pressing plate 3 and the width of the second convex portion 6 is W 3 It can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm or 9.5mm.

[0078] Optionally, refer to Figure 4 The first insulating member 4 includes a first portion 41 and a second portion 42. Along the thickness direction A of the cover plate, the first portion 41 is disposed between the pressing plate 3 and the cover plate 1, and the second portion 42 is connected to the radial outer end of the first portion 41 and covers at least a portion of the radial outer peripheral surface of the pressing plate 3; along the radial direction of the electrode terminal 2, the distance between the second portion 42 and the radial outer peripheral surface of the first protrusion 5 is d 3 , meet: 2.5mm≤d 3 ≤10mm.

[0079] Specifically, along the thickness direction A of the cover plate, the first part 41 is disposed between the pressing plate 3 and the cover plate 1, and the second part 42 is located radially outside the first part 41 and covers at least part of the radial outer peripheral surface of the pressing plate 3. The first part 41 and the second part 42 play the role of insulation and sealing between the pressing plate 3 and the cover plate 1. In addition, the second part 42 covers at least part of the radial outer peripheral surface of the pressing plate 3, plays a role in positioning the pressing plate 3, and improves the reliability of the connection between the pressing plate 3 and the electrode terminal 2. In a specific embodiment, the first part 41 also includes a third part located radially inside the first part 41, the third part is interference-fitted with the electrode terminal 2, the third part is configured as a first mounting hole 40, and the third part further seals and insulates the electrode terminal 2 and the pressing plate 3.

[0080] The welding surface of the electrode terminal 2 and the pressure plate 3 is the radial outer peripheral surface of the first protrusion 5. If the second portion 42 is too close to the radial outer peripheral surface of the first protrusion 5, the heat generated by the laser welding will cause the second portion 42 to be damaged when the electrode terminal 2 and the pressure plate 3 are welded. 3The thickness may be 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm or 9.5 mm. Thus, it is ensured that the second portion 42 will not be damaged by the heat of laser welding when the electrode terminal 2 and the pressing plate 3 are welded together.

[0081] Optionally, refer to Figures 1 to 4 , along the thickness direction A of the cover plate, the electrode terminal 2 includes a first section 26 and a second section 27, the first section 26 is located outside the second section 27, the first insulating member 4 is provided with a first mounting hole 40, the second section 27 is interference fit with the first radial inner peripheral surface 43, the high temperature resistance of the first section 26 is less than that of the second section 27; and the condition is satisfied: 0.15≤h / H≤0.9. Specifically, the material of the first section 26 is aluminum, and the material of the second section 27 is copper, and copper has better high temperature resistance. The dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 cannot be too small. If the dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is too small, relatively speaking, the dimension H of the pressure plate 3 is larger, which will cause the welding fixation between the pressure plate 3 and the electrode terminal 2 to be loose, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, and then causing the sealing failure of the cover plate 1, and is not conducive to current flow; if the dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is too large, the welding area where the pressure plate 3 and the electrode terminal 2 are connected will be too close to the first insulating member 4 and the second section 27 of the copper material, and the welding temperature will be directly or through the second section 27 of the copper material to the first insulating member 4, which is likely to cause the first insulating member 4 to soften, and then cause the insulation failure of the first insulating member 4.

[0082] The ratio h / H of the size h of the first protrusion 5 and the size H of the pressing plate 3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8. While ensuring the connection strength and current capacity between the motor terminal and the pressing plate 3, the damage to the first insulating member 4 during welding of the electrode terminal 2 and the pressing plate 3 is reduced, and the sealing stability of the cover assembly is improved.

[0083] Optionally, refer to Figure 4, there is a connection interface 28 between the first section 26 and the second section 27, and along the thickness direction A of the cover plate, the minimum distance between the first protrusion 5 and the connection interface 28 is d, which satisfies: 0.5mm≤d≤3mm. Since the electrode terminal 2 is welded to the pressing plate 3 at the first protrusion 5, if the minimum distance d between the first protrusion 5 and the connection interface 28 is too small, the heat generated during the welding of the electrode terminal 2 and the pressing plate 3 will be transferred to the second section 27, causing the copper material at the second end to melt, and the molten copper will enter the weld between the electrode terminal 2 and the pressing plate 3, thereby causing the welding strength to decrease; if the minimum distance d between the first protrusion 5 and the connection interface 28 is too large, it means that the aluminum material of the first section 26 of the electrode terminal 2 is large in size along the thickness direction of the cover plate 1, and the copper material of the second section 27 accounts for too small a proportion, which affects the conductivity of the electrode terminal 2. The minimum distance d between the first protrusion 5 and the connection interface 28 along the thickness direction A of the cover plate can be 0.8 mm, 1 mm, 1.2 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.6 mm or 2.8 mm. Therefore, it is necessary to ensure that the second section 27 of the copper material will not be melted by heat when the electrode terminal 2 and the pressing plate 3 are welded at the connection interface 28.

[0084] Optionally, refer to Figure 2 and Figure 4 The first insulating member 4 includes a first portion 41 and a second portion 42. Along the thickness direction A of the cover plate, the first portion 41 is disposed between the pressure plate 3 and the cover plate 1, and the second portion 42 is connected to the radial outer end of the first portion 41 and covers at least part of the radial outer peripheral surface of the pressure plate 3; along the thickness direction A of the cover plate, the minimum distance between the first protrusion 5 and the first portion 41 is d 2 , satisfying: 0.15≤d 2 / d≤5.

[0085] Since the electrode terminal 2 and the pressing plate 3 are welded to the first protrusion 5, the heat generated when the electrode terminal 2 and the pressing plate 3 are welded will be transferred to the inside. 2 The ratio of the distance d between the first protrusion 5 and the connection interface 28 is too small, which means that the first portion 41 of the first insulating member 4 is closer to the first protrusion 5, and the connection interface 28 is closer to the inside. In other words, the proportion of aluminum in the first section 26 of the electrode terminal 2 is larger than that of copper in the second section 27, resulting in poor conductivity of the electrode terminal 2. The heat generated by the aluminum during conduction is greater, which makes the first insulating member 4 susceptible to heat damage.

[0086] Optionally, the minimum distance d between the first protrusion 5 and the first portion 41 is 2 Satisfy: 0.5mm≤d 2 ≤2.5mm. The minimum distance d between the first protrusion 5 and the first portion 41 2It can be 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm or 2.5mm.

[0087] If the distance d from the first protrusion 5 to the first portion 41 2 The ratio of the distance d between the first protrusion 5 and the connection interface 28 is too large, indicating that the first portion 41 of the first insulating member 4 is farther from the first protrusion 5, while the connection interface 28 is closer to the first protrusion 5, that is, the first insulating member 4 is more closely fitted to the copper material of the second section 27 of the electrode terminal 2. Since copper has better thermal conductivity than aluminum, during the welding process of the electrode terminal 2 and the pressing plate 3, the welding heat of the laser welding is easily transferred to the first insulating member 4 by the copper second section 27, resulting in thermal damage to the first insulating member 4. At the same time, during the welding process of the electrode terminal 2 and the pressing plate 3, the welding molten pool is also easily mixed with the copper material, resulting in a decrease in welding strength.

[0088] Therefore, the distance d from the first protrusion 5 to the first portion 41 is 2 The ratio d between the distance d between the first protrusion 5 and the connection interface 28 2 / d can be 0.2, 0.23, 0.25, 0.28, 0.3, 0.33, 0.35, 0.38, 0.4, 0.43, 0.45 or 0.48. It should be understood that no matter whether the first protrusion 5 is disposed on the electrode terminal 2 or the pressing plate 3, the minimum distance d from the first protrusion 5 to the first portion 41 is 2 The ratio of the minimum distance d between the first protrusion 5 and the connection interface 28 must satisfy: 0.15≤d 2 / d≤5.

[0089] Optionally, refer to Figure 2 and Figure 4 The first insulating member 4 includes a first portion 41 and a second portion 42. Along the thickness direction A of the cover plate, the first portion 41 is disposed between the pressure plate 3 and the cover plate 1, and the second portion 42 is connected to the radial outer end of the first portion 41 and covers at least part of the radial outer peripheral surface of the pressure plate 3; along the thickness direction A of the cover plate, the minimum distance between the first protrusion 5 and the first portion 41 is d 2 , must meet: 0.5mm≤d 2 ≤2.5mm. Since the electrode terminal 2 and the pressing plate 3 are welded to the first protrusion 5, if the minimum distance d between the first protrusion 5 and the first portion 41 is 2 If the minimum distance d between the first protrusion 5 and the first part 41 is too small, the heat generated during the welding process of the electrode terminal 2 and the pressing plate 3 can be easily transferred to the first part 41, causing the first insulating member 4 to be damaged by heat. 2It can be 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm or 2.5mm. It should be understood that no matter whether the first protrusion 5 is arranged on the electrode terminal 2 or the pressing plate 3, the minimum distance d from the first protrusion 5 to the first portion 41 is 2 All need to meet: 0.5mm≤d 2 ≤2.5mm.

[0090] Second, reference Figure 5 An embodiment of the present application provides a single cell battery, comprising a shell, an electrode assembly 71, a diaphragm 72 and the cover assembly described in any of the above embodiments, the cover assembly is connected to the shell to form a accommodating chamber; the electrode assembly 71 is arranged in the accommodating chamber, the electrode assembly 71 comprises an electrode assembly 71 body and a pole ear 73, the pole ear 73 is respectively connected to the electrode assembly 71 body and the electrode terminal 2; the diaphragm 72 is arranged on the outside of the electrode assembly 71 body, and the pole ear 73 passes through the diaphragm 72 and is connected to the electrode assembly 71 body.

[0091] In the single cell battery proposed in the embodiment of the present application, the electrode terminal 2 is connected to the pressing plate 3 through the connecting circumferential surface 53 of the first protrusion 5. Along the thickness direction A of the cover plate, there is a second protrusion 6 on the inner side of the connection between the electrode terminal 2 and the pressing plate 3. When the electrode terminal 2 and the pressing plate 3 are welded on the first protrusion 5, the welding heat is shielded by the second protrusion 6, reducing the heat transferred to the first insulating member 4 when the electrode terminal 2 and the pressing plate 3 are welded, thereby reducing the probability of damage to the first insulating member 4, thereby achieving the purpose of improving the reliability of the battery. At the same time, the second protrusion 6 can also reduce the heat transferred to the diaphragm 72 when the electrode terminal 2 and the pressing plate 3 are welded, thereby alleviating the problem of shrinkage of the diaphragm 72.

[0092] Optionally, the first protrusion 5 has a first outer end face 51, a second outer end face 52 and a connecting circumferential surface 53 connecting the first outer end face 51 and the second outer end face 52, the connecting circumferential surface 53 is parallel to the thickness direction A of the cover plate, and along the thickness direction A of the cover plate, the projection of the pole ear 73 at least partially overlaps with the projection of the connecting circumferential surface 53.

[0093] The electrode terminal 2 and the pressure plate 3 are welded together at the connection surface 53. Along the thickness direction A of the cover plate, the projection of the pole ear 73 on the cover plate 1 at least partially overlaps with the projection of the connection surface 53 on the cover plate 1, so that the pole ear 73 can block the battery cell, reduce the heat generated during the welding of the electrode terminal 2 and the pressure plate 3 and transfer to the diaphragm 72, and reduce the shrinkage of the diaphragm 72.

[0094] Optionally, along the thickness direction A of the cover plate, the minimum distance between the first protrusion 5 and the diaphragm 72 is L, satisfying: 5mm≤L≤15mm. If the minimum distance between the first protrusion 5 and the diaphragm 72 is too small, the welding heat during the welding of the electrode terminal 2 and the pressing plate 3 will cause the diaphragm 72 to shrink; if the minimum distance between the first protrusion 5 and the diaphragm 72 is too large, the space utilization rate is low. The minimum distance L between the first protrusion 5 and the diaphragm 72 can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm or 14mm.

[0095] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0096] In some embodiments, the battery may be a battery pack, which includes a battery case and battery cells, wherein the battery cells or battery modules are accommodated in the battery case.

[0097] In some embodiments, the battery cell may be a secondary battery, which refers to a battery cell that can be used continuously by activating the active material by charging after the battery cell is discharged. The battery cell may be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., and the embodiments of the present application are not limited thereto.

[0098] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0099] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0100] The above is only the embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0101] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: Cover plate; Electrode terminal; A pressing plate, disposed on the outer side of the cover plate, the pressing plate is connected to the electrode terminal, and along the thickness direction of the cover plate, the projection of the pressing plate at least partially overlaps with the projection of the cover plate; as well as a first insulating member, at least a portion of which is disposed between the pressing plate and the cover plate, the first insulating member having a first radial inner peripheral surface abutting against the electrode terminal; Among them, a first protrusion is provided on one of the radial outer circumferential surface of the electrode terminal and the radial inner circumferential surface of the pressure plate, and the other of the radial outer circumferential surface of the electrode terminal and the radial inner circumferential surface of the pressure plate is welded to the first protrusion to form a first weld, and a second protrusion is provided on the other of the radial outer circumferential surface of the electrode terminal and the radial inner circumferential surface of the pressure plate, along the thickness direction of the cover plate, the first protrusion is located on the outside of the second protrusion, at least part of the projection of the first protrusion overlaps with the projection of the second protrusion, and the projection of the first weld does not overlap with the projection of the first radial inner circumferential surface.

2. The cover plate assembly according to claim 1, characterized in that: Along the thickness direction of the cover plate, the size of the first protrusion is h, and the size of the pressing plate is H, which satisfies: 0.15≤h / H≤0.

9.

3. The cover plate assembly according to claim 2, characterized in that: The size h of the first protrusion satisfies: 0.5 mm ≤ h ≤ 2 mm; the size H of the pressing plate satisfies: 1.5 mm ≤ H ≤ 3 mm.

4. The cover plate assembly according to claim 1, characterized in that: Along the thickness direction of the cover plate, the size of the first weld is h1, and the size of the first protrusion is h, satisfying: h1<h.

5. The cover plate assembly according to claim 4, characterized in that: A size h1 of the first weld satisfies: 0.5 mm ≤ h ≤ 2 mm, and a size h of the first protrusion satisfies: 0.5 mm ≤ h1 ≤ 2 mm.

6. The cover plate assembly according to claim 5, characterized in that: 0≤h-h1≤1.5mm.

7. The cover plate assembly according to claim 1, characterized in that: The first protrusion is disposed on the radial inner peripheral surface of the pressing plate, and the first protrusion is welded and fixed to the radial outer peripheral surface of the electrode terminal.

8. The cover plate assembly according to claim 7, characterized in that: Along the thickness direction of the cover plate, the outer end of the electrode terminal protrudes from the outer end of the pressing plate to form a first connecting portion, and the first connecting portion is connected to the busbar; Along the radial direction of the electrode terminal, the width of the first protrusion is W1, and the diameter of the first connection portion is D1, which satisfies: 0.0125≤W1 / D1≤0.

2.

9. The cover plate assembly according to claim 8, characterized in that: The width W1 of the first protrusion satisfies: 0.5 mm ≤ W1 ≤ 2 mm, and the diameter D1 of the first connection portion satisfies: 10 mm ≤ D1 ≤ 40 mm.

10. The cover plate assembly according to claim 7, characterized in that: The electrode terminal has a main body that is interference-fitted with the first radial inner peripheral surface, and the outer end of the pressing plate and the outer end of the first protrusion both protrude from the outer end of the electrode terminal to form a second connecting portion, and the second connecting portion is connected to the busbar; Along the radial direction of the electrode terminal, the width of the second connection portion is W2, and the diameter of the main body portion is D2, satisfying: 0.05≤W2 / D2≤0.

8.

11. The cover plate assembly according to claim 10, characterized in that: The width W2 of the second connecting portion satisfies: 2mm≤W2≤8mm, and the diameter D2 of the main body portion satisfies: 10mm≤D2≤40mm.

12. The cover plate assembly according to claim 7, characterized in that: Along the thickness direction of the cover plate, the electrode terminal includes a first main body section and a second main body section, and the first main body section is located outside the second main body section; The outer diameter of the first main body section is smaller than the outer diameter of the second main body section to form a first step surface, and the second protrusion is disposed on the second main body section and is spaced apart from the first step surface in the thickness direction of the cover plate.

13. The cover plate assembly according to claim 12, characterized in that: Along the thickness direction of the cover plate, the first step surface, the outer end surface of the first protrusion and the outer end surface of the pressing plate are flush.

14. The cover plate assembly according to claim 7, characterized in that: The first insulating member includes a first portion and a second portion, along the thickness direction of the cover plate, the first portion is disposed between the pressing plate and the cover plate, and the second portion is connected to the radial outer end of the first portion and covers at least a portion of the radial outer peripheral surface of the pressing plate; Along the radial direction of the electrode terminal, a distance between the second portion and the radial inner circumferential surface of the first protrusion is d3, which satisfies: 2.5 mm ≤ d3 ≤ 10 mm.

15. The cover plate assembly according to claim 1, characterized in that: The first protrusion is disposed on the radial outer peripheral surface of the electrode terminal, and the first protrusion is fixed to the inner peripheral surface of the pressing plate by welding.

16. The cover plate assembly according to claim 15, characterized in that: Along the radial direction of the electrode terminal, the width of the first protrusion is W1, and the sum of the width of the pressing plate and the width of the second protrusion is W3, satisfying: 0.05≤W1 / W3≤0.

8.

17. The cover plate assembly according to claim 16, characterized in that: The width W1 of the first protrusion satisfies: 0.5 mm ≤ W1 ≤ 2 mm, and the sum W3 of the width of the pressing plate and the width of the second protrusion satisfies: 2.5 mm ≤ W3 ≤ 10 mm.

18. The cover plate assembly according to claim 15, characterized in that: The first insulating member includes a first portion and a second portion, along the thickness direction of the cover plate, the first portion is disposed between the pressing plate and the cover plate, and the second portion is connected to the radial outer end of the first portion and covers at least a portion of the radial outer peripheral surface of the pressing plate; Along the radial direction of the electrode terminal, a distance between the second portion and the radial outer peripheral surface of the first protrusion is d3, which satisfies: 2.5 mm ≤ d3 ≤ 10 mm.

19. The cover plate assembly according to claim 2, characterized in that: Along the thickness direction of the cover plate, the electrode terminal includes a first section and a second section, the first section is located outside the second section, the second section is interference fit with the first radial inner peripheral surface, and the high temperature resistance of the first section is lower than that of the second section; Satisfies: 0.15≤h / H≤0.

9.

20. The cover plate assembly according to claim 19, characterized in that A connection interface is provided between the first section and the second section. Along the thickness direction of the cover plate, a minimum distance between the first protrusion and the connection interface is d, satisfying: 0.5 mm ≤ d ≤ 3 mm.

21. The cover plate assembly according to claim 20, characterized in that: The first insulating member includes a first portion and a second portion, along the thickness direction of the cover plate, the first portion is disposed between the pressing plate and the cover plate, and the second portion is connected to the radial outer end of the first portion and covers at least a portion of the radial outer peripheral surface of the pressing plate; Along the thickness direction of the cover plate, the minimum distance between the first protrusion and the first portion is d2, satisfying: 0.15≤d2 / d≤5.

22. The cover plate assembly according to claim 21, characterized in that: A minimum distance d2 between the first protrusion and the first portion satisfies: 0.5 mm≤d2≤2.5 mm.

23. The cover plate assembly according to claim 1, characterized in that The first insulating member includes a first portion and a second portion, along the thickness direction of the cover plate, the first portion is disposed between the pressing plate and the cover plate, and the second portion is connected to the radial outer end of the first portion and covers at least a portion of the radial outer peripheral surface of the pressing plate; Along the thickness direction of the cover plate, the minimum distance between the first protrusion and the first portion is d2, which must satisfy: 0.5 mm ≤ d2 ≤ 2.5 mm.

24. A single cell battery, characterized in that: include: case; The cover plate assembly according to any one of claims 1 to 23, wherein the cover plate assembly is connected to the housing to form a receiving chamber; An electrode assembly is disposed in the accommodating chamber, wherein the electrode assembly comprises an electrode assembly body and a tab, wherein the tab is connected to the electrode assembly body and the electrode terminal respectively; as well as A diaphragm is arranged on the outside of the electrode assembly body, and the electrode tab passes through the diaphragm and is connected to the electrode assembly body.

25. The single cell according to claim 24, characterized in that: in, The first convex portion has a first outer end face, a second outer end face and a connecting circumferential surface connecting the first outer end face and the second outer end face, the connecting circumferential surface is parallel to the thickness direction of the cover plate, and along the thickness direction of the cover plate, the projection of the pole ear and the projection of the connecting circumferential surface at least partially overlap.

26. The single cell according to claim 25, characterized in that: Along the thickness direction of the cover plate, the minimum distance between the first protrusion and the diaphragm is L, which satisfies: 5mm≤L≤15mm.

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