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

This application is a divisional application. The original application has the application number 2024117792548 and the original application date is December 5, 2024. The entire contents of the original application are incorporated herein by reference. Technical Field

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

[0002] In related technologies, the cover plate assembly includes a cover plate body, a pressure plate, and electrode terminals. The electrode terminals are welded to the pressure plate. During the welding process between the electrode terminals and the pressure plate, the welding heat is relatively large, which causes the insulation between the pressure plate and the cover plate body to soften due to heat, thereby leading to insulation failure and affecting battery performance. Summary of the Invention

[0003] This application provides a cover plate assembly and a single battery cell, which solves the technical problem of insulation failure caused by the heat of welding between the pressure plate and the electrode terminals, resulting in the softening of the insulating components. This reduces the heat damage to the insulating components caused by welding heat and improves the reliability of the battery.

[0004] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a cover plate assembly, including a cover plate, an electrode terminal, a pressure plate, and a first insulating member. The electrode terminal penetrates the cover plate along its thickness direction. The pressure plate is disposed on the outer side of the cover plate and connected to the electrode terminal. Along the thickness direction of the cover plate, the projection of the pressure plate at least partially coincides with the projection of the cover plate. At least a portion of the first insulating member is disposed between the pressure plate and the cover plate, and the first insulating member has a first radially inner circumferential surface that abuts against the electrode terminal. A first protrusion is provided on one of the radially outer circumferential surface of the electrode terminal and the radially inner circumferential surface of the pressure plate. The first protrusion is welded to the other of the radial inner circumferential surfaces of the pressure plate to form a first weld. The other of the radial outer circumferential surfaces of the electrode terminal and the radial inner circumferential surfaces of the pressure plate is provided with a second protrusion. Along the thickness direction of the cover plate, the first protrusion is located outside the second protrusion. At least a portion of the projection of the first protrusion overlaps with the projection of the second protrusion. The projection of the first weld does not overlap with the projection of the first radial inner circumferential surface. 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: 0.5mm≤h≤2mm, 0.5mm≤h1≤2mm, 0≤h-h1≤1.5mm.

[0005] The cover plate assembly proposed in this application has an electrode terminal that penetrates the cover plate and connects to a pressure plate. One of the radially outer circumferential surface of the electrode terminal and the radially inner circumferential surface of the pressure plate has a first protrusion, and the other has a second protrusion. The first protrusion covers the outside of the second protrusion. The electrode terminal penetrates the cover plate and is connected to the pressure plate through the first protrusion, thus fixing the electrode terminal. The electrode terminal and the pressure plate are welded together through the first protrusion to form a first weld. Along the thickness direction of the cover plate, at least a portion of the projection of the first protrusion overlaps with the projection of the second protrusion. When the electrode terminal and the pressure plate are welded, the welding heat is shielded by the second protrusion, reducing the heat transferred to the first insulating component during welding. Simultaneously, along the thickness direction of the cover plate, the projection of the first weld does not overlap with the projection of the first radially inner circumferential surface, reducing the heat transfer to the first insulating component during welding through the first protrusion, thereby reducing the probability of damage to the first insulating component.

[0006] In addition, limiting the dimensions of the first protrusion and the first weld ensures the connection strength and current carrying capacity between the motor terminal and the pressure plate, while reducing damage to the first insulating component during welding of the electrode terminal and the pressure plate, thereby improving the sealing stability of the cover plate assembly.

[0007] Secondly, embodiments of this application provide a single-cell battery, including a casing, an electrode assembly, a separator, and a cover assembly as described in any of the above embodiments. The cover assembly is connected to the casing to form a receiving chamber. The electrode assembly is disposed in the receiving chamber and includes an electrode assembly body and tabs. The tabs are respectively connected to the electrode assembly body and the electrode terminals. The separator is disposed on the outside of the electrode assembly body, and the tabs pass through the separator and are connected to the electrode assembly body.

[0008] The single-cell battery proposed in this application has an electrode terminal connected to a pressure plate via a first protrusion on its connecting circumferential surface. Along the thickness direction of the cover plate, a second protrusion is located on the inner side of the connection between the electrode terminal and the pressure plate. When the electrode terminal and the pressure plate are welded to the first circumferential surface, the heat generated during welding is shielded by the second protrusion, reducing the heat transferred to the first insulating component during welding. This reduces the probability of damage to the first insulating component and improves battery reliability. Simultaneously, the second protrusion also reduces the heat transferred to the separator during welding, thus alleviating the problem of separator shrinkage. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a cross-sectional structural schematic diagram of a cover plate assembly according to an embodiment of this application; Figure 2 for Figure 1 Enlarged view of region B in the middle; Figure 3 This is a cross-sectional structural schematic diagram of a cover plate assembly according to another embodiment of this application; Figure 4 for Figure 3 Enlarged view of region C in the middle; Figure 5 This is a schematic diagram of a single battery cell.

[0011] [Explanation of Labels in the Attached Image] 1: Cover plate; 2: Electrode terminal; 21: First connecting part; 22: Main body part; 23: First main body segment; 24: Second main body segment; 25: First stepped surface; 26: First segment; 27: Second segment; 28: Connecting interface; 3: Pressure plate; 31: Second connecting part; 4: First insulating element; 40: First mounting hole; 41: First part; 42: Second part; 43: First radial inner circumferential surface; 5: First protrusion; 51: First outer end face; 52: Second outer end face; 53: Connecting peripheral surface; 54: First weld; 6: The second convex part; 71: Electrode assembly; 72: Diaphragm; 73: Tab; A: The thickness direction of the cover plate. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0014] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0015] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0016] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0017] In this application, "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0018] In related technologies, the cover plate assembly includes a cover plate body, a pressure plate, and electrode terminals. The electrode terminals are welded to the pressure plate. During the welding process between the electrode terminals and the pressure plate, the welding heat is large, and the laser is prone to light leakage, which causes the insulation between the pressure plate and the cover plate body to soften due to heat, thereby leading to insulation failure and affecting battery performance.

[0019] Therefore, in order to reduce insulation failure and improve battery reliability, embodiments of this application provide a cover plate assembly. (See reference...) Figures 1 to 4The cover plate assembly includes a cover plate 1, electrode terminals 2, a pressure plate 3, and a first insulating component 4.

[0020] Along the thickness direction A of the cover plate, the electrode terminal 2 penetrates the cover plate 1; the pressure plate 3 is disposed on the outside of the cover plate 1 and is connected to the electrode terminal 2. Along the thickness direction A of the cover plate, the projection of the pressure plate 3 at least partially coincides with the projection of the cover plate 1; at least part of the first insulating member 4 is disposed between the pressure plate 3 and the cover plate 1. The first insulating member 4 has a first radial inner circumferential surface 43 that abuts against the electrode terminal 2; wherein, one of the radial outer circumferential surface of the electrode terminal 2 and the radial inner circumferential surface of the pressure plate 3 is provided with a first protrusion 5, the other of the radial outer circumferential surface of the electrode terminal 2 and the radial inner circumferential surface of the pressure plate 3 is welded to the first protrusion 5 to form a first weld 54, and the other of the radial outer circumferential surface of the electrode terminal 2 and the radial inner circumferential surface of the pressure plate 3 is provided with a second protrusion 6. Along the thickness direction A of the cover plate, the first protrusion 5 is located outside the second protrusion 6, at least part of the projection of the first protrusion 5 overlaps with the projection of the second protrusion 6, and the projection of the first weld 54 does not overlap with the projection of the first radial inner circumferential surface 43.

[0021] The cover plate assembly proposed in this application embodiment has an electrode terminal 2 penetrating through a cover plate 1 and connected to a pressure plate 3. One of the radially outer circumferential surface of the electrode terminal 2 and the radially inner circumferential surface of the pressure plate 3 has a first protrusion 5, and the other has a second protrusion 6. The first protrusion 5 covers the outside of the second protrusion 6. The electrode terminal 2 penetrates through the cover plate 1 and is connected to the pressure plate 3 through the first protrusion 5, thereby fixing the electrode terminal 2. The electrode terminal 2 and the pressure plate 3 are welded together through the first protrusion 5 to form a first weld 54, wherein the connection point between the electrode terminal 2 and the pressure plate 3 through the first protrusion 5 extends along the thickness direction A of the cover plate. Along the thickness direction A of the cover plate, at least a portion 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, 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, 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.

[0022] Along the thickness direction A of the cover plate, the side facing the pressure plate 3 is the outer side, and the side away from the pressure plate 3 is the inner side. The electrode terminal 2 passes through the inner side of the cover plate 1 and extends to the outer side of the cover plate 1. The pressure plate 3 is located on the outer side of the cover plate 1, and at the first protrusion 5, the electrode terminal 2 is welded to the pressure plate 3 to form a first weld 54. The first weld 54 has a second protrusion 6 on the inner side along the thickness direction of the cover plate 1. When the electrode terminal 2 is welded to the pressure plate 3, the second protrusion 6 protects the first insulating component 4 and reduces damage to the first insulating component 4 caused by the welding heat.

[0023] Meanwhile, since the projection of the first weld 54 does not overlap with the projection of the first radial inner circumferential 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 component 4, thereby reducing the probability of the first insulating component 4 being damaged by heat.

[0024] Specifically, when the first protrusion 5 is provided on the pressure plate 3, the second protrusion 6 is provided on the electrode terminal 2. The electrode terminal 2 has an electrode terminal 2 step that mates with the first protrusion 5. 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. The second protrusion 6 and the electrode terminal 2 step share the surface perpendicular to the thickness direction of the cover plate 1. The welding surfaces of the pressure plate 3 and the electrode terminal 2 are the radial inner circumferential surface of the first protrusion 5 and the surface of the electrode terminal 2 step parallel to the thickness direction of the cover plate 1.

[0025] When the first protrusion 5 is provided on the electrode terminal 2, the second protrusion 6 is provided on the pressure plate 3, and the pressure plate 3 has a step that mates with the first protrusion 5. The step of the pressure plate 3 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. The second protrusion 6 and the step of the pressure plate 3 share the surface perpendicular to the thickness direction of the cover plate 1. The welding surfaces of the pressure plate 3 and the electrode terminal 2 are the surfaces of the first protrusion 5 and the step of the pressure plate 3 parallel to the thickness direction of the cover plate 1.

[0026] 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. The first protrusion 5 is formed on the outer side of the pressure plate 3 along the thickness direction of the cover plate 1 by cutting off a piece from the radial inner surface of the pressure plate 3. The second protrusion 6 on the electrode terminal 2 is formed by cutting off a piece from the radial outer surface of the electrode terminal 2 inward, so that the first protrusion 5 can overlap the second protrusion 6.

[0027] 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 is an integral structure with the pressure plate 3, and a piece is cut off from the radial inner surface of the pressure 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 pressure plate 3 along the thickness direction of the cover plate 1, so that the first protrusion 5 can overlap the second protrusion 6.

[0028] Optionally, refer to Figure 2 The dimensions h of the first protrusion 5 and H of the pressure plate 3 satisfy: 0.15 ≤ h / H ≤ 0.9. The dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is h, and the dimension H of the pressure plate 3 along the thickness direction is H. 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, the dimension H of the pressure plate 3 will be relatively large, which will lead to the welding and fixing between the pressure plate 3 and the electrode terminal 2 being not firm, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, thus leading to the sealing failure of the cover plate assembly, and is not conducive to overcurrent. If the dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is too large, it will cause the welding area connecting the pressure plate 3 and the electrode terminal 2 to be too close to the first insulating component 4, and the welding temperature will easily cause the first insulating component 4 to soften, thus leading to the insulation failure of the first insulating component 4.

[0029] Therefore, the ratio h / H of the size h of the first protrusion 5 and the size H of the pressure plate 3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8. This ensures the connection strength and current carrying capacity between the motor terminals and the pressure plate 3, while reducing damage to the first insulating component 4 during welding of the electrode terminals 2 and the pressure plate 3, thus improving the sealing stability of the cover assembly.

[0030] Optionally, refer to Figure 2 Along the thickness direction A of the cover plate, the dimension of the first protrusion 5 is h, and the dimension of the pressure plate 3 is H, satisfying: 0.5mm≤h≤2mm, 1.5mm≤H≤3mm. 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, it will cause the welding fixation between the pressure plate 3 and the electrode terminal 2 to be not firm, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, which will lead to the sealing failure of the cover plate assembly and is not conducive to overcurrent. If the dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is too large, it will cause the welding area connecting the pressure plate 3 and the electrode terminal 2 to be too close to the first insulating component 4, and the welding temperature will easily cause the first insulating component 4 to soften, which will lead to the insulation failure of the first insulating component 4.

[0031] 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 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, or 1.8mm. This ensures the connection strength and current carrying capacity between the motor terminal and the pressure plate 3 while reducing damage to the first insulating component 4 during welding of the electrode terminal 2 and the pressure plate 3.

[0032] Along the thickness direction A of the cover plate, the dimension of the pressure plate 3 along the thickness direction is H. If the dimension H of the pressure plate 3 is too small, the welding and fixing between the pressure plate 3 and the electrode terminal 2 will not be firm, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, which will lead to the sealing failure of the cover plate 1 and will not be conducive to overcurrent. If the dimension H of the pressure plate 3 is too large, the pressure plate 3 needs to bear a large load. If the load-bearing capacity of the cover plate assembly is insufficient to support the pressure plate 3, it will lead to the sealing failure of the cover plate 1.

[0033] Along the thickness direction A of the cover plate, the dimension H of the pressure plate 3 can be 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, or 2.8mm. This ensures that the dimensions of the pressure plate 3 are appropriate, that the cover plate assembly has sufficient load-bearing capacity for it, and at the same time improves the connection strength between the electrode terminal 2 and the pressure plate 3, thereby enhancing the sealing stability of the cover plate assembly.

[0034] Optionally, refer to Figure 2 Along the thickness direction A of the cover plate, the dimension of the first weld 54 is h1, and the dimension of the first protrusion 5 is h, satisfying that h1 < h. The first protrusion 5 has a first outer end face 51, a second outer end face 52, and a connecting peripheral surface 53 connecting the first outer end face 51 and the second outer end face 52. The connecting peripheral surface 53 is parallel to the thickness direction A of the cover plate. The connecting peripheral surface 53 has a first welding area. The connecting surface of the electrode terminal 2 and the pressure plate 3 is the connecting peripheral surface 53 of the first protrusion 5. The electrode terminal 2 and the pressure plate 3 are welded on the connecting peripheral surface 53 to form the first weld 54, which extends along the thickness direction of the cover plate 1. The dimension h1 of the first weld 54 and the dimension h of the first protrusion 5 satisfy that h1 < h. In other words, given a fixed size for the first weld 54, 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, thereby reducing laser leakage during laser welding of the pressure plate 3 and the electrode terminal 2, which could cause the laser to hit the first insulating component 4, thus reducing the softening of the first insulating component 4 due to heat, and further reducing the insulation failure of the first insulating component 4.

[0035] Optionally, the dimension h1 of the first weld 54 satisfies: 0.5mm ≤ h ≤ 2mm, and the dimension h of the first protrusion 5 satisfies: 0.5mm ≤ h1 ≤ 2mm. The dimension h1 of the first weld 54 can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, or 1.8mm. The dimension h of the first protrusion 5 along the thickness direction of the cover plate 1 is 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, or 1.8mm.

[0036] Optionally, 0 ≤ h - h1 ≤ 1.5 mm. 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 should not be too small. If the difference is too small, laser leakage is likely during laser welding of the pressure plate 3 and the electrode terminal 2, causing the laser to hit the first insulating component 4, resulting in heat damage to the first insulating component 4 and subsequent insulation failure. The difference between 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 should not be too large. If the difference is too large, it indicates that the size of the first weld 54 is too small, which will result in insufficient welding strength between the pressure plate 3 and the electrode terminal 2, leading to sealing failure of the cover plate 1.

[0037] Along the thickness direction A of the cover plate, the difference between the dimension h of the first protrusion 5 and the dimension h1 of the first welding area can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm or 1.4mm.

[0038] Optionally, refer to Figure 1 and Figure 2 A first protrusion 5 is disposed on the radial inner circumferential surface of the pressure plate 3, and is welded and fixed to the radial outer circumferential surface of the electrode terminal 2. The first protrusion 5 is disposed on the radial inner circumferential surface of the pressure plate 3, and a second protrusion 6 is disposed on the radial outer circumferential surface of the electrode terminal 2. That is, the second protrusion 6 protrudes beyond the radial outer circumferential surface of the electrode terminal 2, and a step for the electrode terminal 2 is formed on the outer side of the second protrusion 6. The first protrusion 5 overlaps the step for 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 circumferential surface of the electrode terminal 2 at the step for the electrode terminal 2. When the electrode terminal 2 and the pressure plate 3 are welded, the heat of the weld is shielded by the second protrusion 6, reducing the heat transfer from the weld between the electrode terminal 2 and the pressure plate 3 to the first insulating member 4, thereby reducing damage to the first insulating member 4.

[0039] Optionally, refer to Figure 1 and Figure 2Along the thickness direction A of the cover plate, the outer end of the electrode terminal 2 protrudes from the outer end of the pressure plate 3 to form a first connecting part 21, which is connected to the busbar; along the radial direction of the electrode terminal 2, the width of the first protrusion 5 is W1, and the diameter of the first connecting part 21 is D1, satisfying: 0.0125≤W1 / D1≤0.2.

[0040] Specifically, the first protrusion 5 is provided on the pressure plate 3, and the second protrusion 6 is provided on the electrode terminal 2. The second protrusion 6 has a step for the electrode terminal 2 on the outer side along the thickness direction A of the cover plate. The first protrusion 5 overlaps the step of the electrode terminal 2 and is welded to the step of the electrode terminal 2 on the connecting circumferential surface 53. The electrode terminal 2 has 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. Along the radial direction of the electrode terminal 2, the width of the first protrusion 5 is W1, that is, the width of the step of the electrode terminal 2 along the radial direction of the electrode terminal 2 is W1. The diameter of the first connecting portion 21 is D1, satisfying: 0.0125≤W1 / D1≤0.2.

[0041] 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 part 21 will be reduced relative to the diameter of the second protrusion 6. The first connecting part 21 on the surface of the electrode terminal 2 is welded to the busbar. If the diameter D1 of the first connecting part 21 is reduced, the surface area of ​​the first connecting part 21 will be small, and the welding area with the busbar will be reduced, thereby affecting the current carrying capacity of the electrode terminal 2 and the first connecting part 21.

[0042] If the width W1 of the first protrusion 5 is too wide, it will affect the current carrying capacity of the electrode terminal 2; if the width W1 of the first protrusion 5 is too narrow, it will cause the electrode terminal 2 and the pressure plate 3 to be difficult to weld and the welding strength will be insufficient. At the same time, if the width W1 of the first protrusion 5 is too narrow, the projection on the cover plate 1 of the welding surface of the electrode terminal 2 and the pressure plate 3 will be 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 inward, which will cause the welding heat to affect the first insulating component 4, resulting in the first insulating component 4 being damaged by heat.

[0043] Therefore, to ensure the current-carrying capacity of the first connecting portion 21 and reduce damage to the first insulating member 4, the following condition must be met: 0.0125 ≤ W1 / D1 ≤ 0.2. The ratio W1 / D1 of the width W1 of the first protrusion 5 to the diameter D1 of the first connecting portion 21 can be 0.02, 0.03, 0.04, 0.05, 0.08, 0.1, 0.14, 0.16, or 0.18.

[0044] Optionally, the width W1 of the first protrusion 5 satisfies: 0.5mm ≤ W1 ≤ 2mm, and the diameter D1 of the first connecting portion 21 satisfies: 10mm ≤ D1 ≤ 40mm. The diameter D1 of the first connecting portion 21 can be 15mm, 20mm, 25mm, 30mm, 35mm, or 38mm. The width W1 of the first protrusion 5 can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, or 1.8mm.

[0045] 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 busbar, the outer side of the electrode terminal 2 has a first connecting part 21. The first connecting part 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.

[0046] Optionally, refer to Figure 1 The electrode terminal 2 has a main body 22 that is interference-fitted with the first radial inner circumferential surface 43. The outer end of the pressure 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 connection 31. The second connection 31 is connected to the busbar. Along the radial direction of the electrode terminal 2, the width of the second connection 31 is W2, and the diameter of the main body 22 is D2, satisfying: 0.05≤W2 / D2≤0.8.

[0047] The first insulating member 4 has a first mounting hole 40, the radial inner surface of which 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-fitted with the electrode terminal 2. The first insulating member 4 serves both sealing and insulation functions. The outer ends of the pressure 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 the sum of the width of the pressure plate 3 and the width of the first protrusion 5. Since the connection between the second connecting portion 31 and the busbar requires control of the current carrying capacity of the second connecting portion 31, if the width W2 of the second connecting portion 31 along the radial direction of the electrode terminal 2 is too small, the current carrying capacity of the second connecting portion 31 will be insufficient.

[0048] The ratio W2 / D2 of the width W2 of the second connecting part 31 to the diameter D2 of the main body part 22 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7, thereby ensuring sufficient flow capacity.

[0049] Optionally, the width W2 of the second connecting portion 31 satisfies: 2mm ≤ W2 ≤ 8mm, and the diameter D2 of the main body portion 22 satisfies: 10mm ≤ D2 ≤ 40mm. The width W2 of the second connecting portion 31 can be 3mm, 4mm, 5mm, 6mm, or 7mm, thereby satisfying the current-carrying capacity of the second connecting portion 31. The diameter D2 of the main body portion 22 of the electrode terminal 2 can be 15mm, 20mm, 25mm, 30mm, 35mm, or 38mm, thereby satisfying the current-carrying capacity of the electrode terminal 2.

[0050] It should be understood that, along the thickness direction of the pressure plate 3, the outer side of the pressure plate 3 is flush with the outer side of the first protrusion 5, so as to better connect with the busbar.

[0051] Optionally, refer to Figure 2 Along the thickness direction A of the cover plate, the electrode terminal 2 includes a first main body segment 23 and a second main body segment 24. The first main body segment 23 is located outside the second main body segment 24. The outer diameter of the first main body segment 23 is smaller than the outer diameter of the second main body segment 24 to form a first stepped surface 25. A second protrusion 6 is disposed on the second main body segment 24 and spaced apart from the first stepped surface 25 along the thickness direction A of the cover plate. Specifically, along the thickness direction A of the cover plate, the electrode terminal 2 consists of a second main body segment 24 and a first main body segment 23 from the inside to the outside. The outer diameter of the first main body segment 23 is smaller than the outer diameter of the second main body segment 24 to form the first stepped surface 25. The first main body segment 23 is connected to the busbar along the outer side of the thickness direction of the cover plate 1. The second protrusion 6 is disposed on the radially outer side of the second main body segment 24. Along the radial direction of the electrode terminal 2, the second protrusion 6 protrudes from the second main body segment 24 to form a step of the electrode terminal 2. The step of the electrode terminal 2 has a step surface of the electrode terminal 2. Along the thickness direction A of the cover plate, the step surface of the electrode terminal 2 is spaced apart from the first stepped surface 25. Because the weld pool at the welding point between electrode terminal 2 and pressure 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 between 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.

[0052] Optionally, refer to Figure 2Along the thickness direction A of the cover plate, the outer end face of the first step surface 25, the outer end face of the first protrusion 5, and the outer end face of the pressure plate 3 are flush. A second protrusion 6 is located radially outward 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, forming a step for the electrode terminal 2. The step for the electrode terminal 2 has a 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; therefore, a 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 step surface of the electrode terminal 2 is spaced apart 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 outer end face of the first step surface 25, the outer end face of the first protrusion 5, and the outer end face of the pressure plate 3 are flush to better control the weld pool between the pressure plate 3 and the electrode terminal 2, thereby making the connection between the first main body section 23 and the busbar more reliable.

[0053] Optionally, refer to Figure 1 and Figure 2 The first insulating member 4 includes a first part 41 and a second part 42. Along the thickness direction A of the cover plate, the first part 41 is disposed between the pressure plate 3 and the cover plate 1, and the second part 42 is connected to the radial outer end of the first part 41 and covers at least a portion of the radial outer peripheral surface of the pressure plate 3. Along the radial direction of the electrode terminal 2, the distance between the second part 42 and the radial inner peripheral surface of the first protrusion 5 is d3, which satisfies: 2.5mm≤d3≤10mm.

[0054] Specifically, along the thickness direction A of the cover plate, a first part 41 is disposed between the pressure plate 3 and the cover plate 1, and a second part 42 is located radially outward of the first part 41 and covers at least a portion of the radial outer circumferential surface of the pressure plate 3. The first part 41 and the second part 42 serve to insulate and seal between the pressure plate 3 and the cover plate 1. Furthermore, the second part 42 covering at least a portion of the radial outer circumferential surface of the pressure plate 3 serves to position the pressure plate 3, thereby improving the reliability of the connection between the pressure plate 3 and the electrode terminal 2.

[0055] The welding surface between electrode terminal 2 and pressure plate 3 is the radial outer circumferential surface of the first protrusion 5. If the second part 42 is too close to the radial outer circumferential surface of the first protrusion 5, the heat generated by laser welding during the welding connection of electrode terminal 2 and pressure plate 3 will cause damage to the second part 42. The distance d3 between the second part 42 and the radial inner circumferential surface of the first protrusion 5 can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, or 9.5mm. This ensures that the second part 42 will not be damaged by the heat of laser welding during the welding connection of electrode terminal 2 and pressure plate 3.

[0056] In one specific embodiment, the first insulating member 4 further includes a third part located radially inside the first part 41. The third part is interference-fitted with the electrode terminal 2. The first radially inner circumferential surface 43 of the third part is configured as a first mounting hole 40. The third part further seals and insulates the electrode terminal 2 and the cover plate 1.

[0057] Optionally, refer to Figure 3 and Figure 4 A first protrusion 5 is disposed 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 pressure plate 3. The first protrusion 5 is disposed on the radial outer peripheral surface of the electrode terminal 2, and a second protrusion 6 is disposed on the radial inner peripheral surface of the pressure plate 3. Along the thickness direction A of the cover plate, a stepped surface of the pressure plate 3 is formed on the outer side of the second protrusion 6. The first protrusion 5 overlaps on the step of the pressure 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 pressure plate 3. When the electrode terminal 2 and the pressure plate 3 are welded, the heat of welding is shielded by the second protrusion 6, reducing the heat transfer from the welding of the electrode terminal 2 and the pressure plate 3 to the first insulating member 4, thereby reducing damage to the first insulating member 4.

[0058] The first protrusion 5 is located on the electrode terminal 2, and the second protrusion 6 is located on the pressure plate 3. A step of the pressure plate 3 is formed on the outer side of the second protrusion 6 along the thickness direction of the pressure plate 3. The first protrusion 5 covers the step of the pressure plate 3 and is welded to the pressure plate 3. The first protrusion 5 on the electrode terminal 2 increases the outer diameter of the electrode terminal 2 at this location, improving the current-carrying capacity. Furthermore, in the manufacturing process of the electrode terminal 2, a ring can be cut open around the outer periphery of the electrode terminal 2 to form the first protrusion 5, and then the electrode terminal 2 and the pressure plate 3 can be butt-welded at the first protrusion 5. This process is simple to implement and results in higher structural strength.

[0059] It should be understood that when the first protrusion 5 is disposed on the electrode terminal 2, if the electrode terminal 2 is connected to the busbar, the outer side of the electrode terminal 2 has a first connecting part 21. The first connecting part 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.

[0060] If the pressure plate 3 is connected to the busbar, the outer end of the pressure 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. The width of the second connecting portion 31 along the radial direction of the electrode terminal 2 is W2. Since the connection between the second connecting portion 31 and the busbar requires control of the current-carrying capacity of the second connecting portion 31, if the width W2 of the second connecting portion 31 along the radial direction of the electrode terminal 2 is too small, the current-carrying capacity of the second connecting portion 31 will be insufficient. Therefore, it is necessary to control the ratio between the width of the second connecting portion 31 along the radial direction of the electrode terminal 2 and the diameter D2 of the main body 22 of the electrode terminal 2, satisfying: 0.06≤W2 / D2≤0.8. Furthermore, along the thickness direction of the pressure plate 3, the outer surface of the first connecting portion 21 protrudes from the outer surface of the first protrusion 5 to better connect with the busbar.

[0061] In one specific embodiment, the portion of the electrode terminal 2 located inside the cover plate 1 has a flange. 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 serves to seal and insulate. When the first protrusion 5 is provided on the electrode terminal 2, the first protrusion 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 protrusion 5 together clamp the cover plate 1, improving the structural strength of the cover plate assembly.

[0062] Optionally, refer to Figure 4 Along the radial direction of electrode terminal 2, the width of the first protrusion 5 is W1, and the sum of the widths of the pressure plate 3 and the second protrusion 6 is W3, satisfying: 0.05≤W1 / W3≤0.8. It should be understood that if the first protrusion 5 is located on electrode terminal 2 and the second protrusion 6 is located on pressure plate 3, the second protrusion 6 has a stepped surface of pressure plate 3 on its outer side along the thickness direction of cover plate 1. Along the radial direction of electrode terminal 2, the width of the stepped surface of pressure plate 3 is the same as the width of the first protrusion 5. Along the radial direction of electrode terminal 2, if the width of the first protrusion 5 is too large, the width of the stepped surface of pressure plate 3 is also too large, reducing the width of pressure plate 3. This results in insufficient structural strength at the step of pressure plate 3, making the root of the step, i.e., the connection between the second protrusion 6 and pressure plate 3, more prone to fracture after being affected by welding heat. If the width of the first protrusion 5 is too small, welding laser and heat can easily leak inward from the connection between electrode terminal 2 and pressure plate 3 to the first insulating component 4, causing the first insulating component 4 to be damaged by heat, leading to insulation failure.

[0063] The ratio W1 / W3 of the width W1 of the first protrusion 5 to the sum of the widths of the pressure plate 3 and the second protrusion 6 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7. This ensures a stable connection between the electrode terminal 2 and the pressure plate 3, and reduces the damage to the first insulating component 4 caused by the heat from welding the electrode terminal 2 and the pressure plate 3.

[0064] Optionally, the width W1 of the first protrusion 5 satisfies: 0.5mm≤W1≤2mm, and the sum of the width of the pressure plate and the width of the second protrusion W3 satisfies: 2.5mm≤W3≤10mm. The width W1 of the first protrusion 5 can be 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm or 1.8mm.

[0065] The sum of the width of the pressure plate 3 and the width of the second protrusion 6, W3, can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, or 9.5mm.

[0066] Optionally, refer to Figure 4 The first insulating member 4 includes a first part 41 and a second part 42. Along the thickness direction A of the cover plate, the first part 41 is disposed between the pressure plate 3 and the cover plate 1, and the second part 42 is connected to the radial outer end of the first part 41 and covers at least a portion of the radial outer peripheral surface of the pressure plate 3. Along the radial direction of the electrode terminal 2, the distance between the second part 42 and the radial outer peripheral surface of the first protrusion 5 is d3, which satisfies: 2.5mm≤d3≤10mm.

[0067] Specifically, along the thickness direction A of the cover plate, a first part 41 is disposed between the pressure plate 3 and the cover plate 1, and a second part 42 is located radially outside the first part 41 and covers at least a portion of the radially outer peripheral surface of the pressure plate 3. The first part 41 and the second part 42 serve to insulate and seal between the pressure plate 3 and the cover plate 1. Furthermore, the second part 42 covering at least a portion of the radially outer peripheral surface of the pressure plate 3 serves to position the pressure plate 3, improving the reliability of the connection between the pressure plate 3 and the electrode terminal 2. In one specific embodiment, the first part 41 further includes a third part located radially inside the first part 41. The third part is interference-fitted with the electrode terminal 2, and the third part is configured as a first mounting hole 40. The third part further seals and insulates between the electrode terminal 2 and the pressure plate 3.

[0068] The welding surface between electrode terminal 2 and pressure plate 3 is the radial outer circumferential surface of the first protrusion 5. If the second part 42 is too close to the radial outer circumferential surface of the first protrusion 5, the heat generated by laser welding during the welding connection of electrode terminal 2 and pressure plate 3 will cause damage to the second part 42. The distance d3 between the second part 42 and the radial inner circumferential surface of the first protrusion 5 can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, or 9.5mm. This ensures that the second part 42 will not be damaged by the heat of laser welding during the welding connection of electrode terminal 2 and pressure plate 3.

[0069] Optionally, refer to Figures 1 to 4Along the thickness direction A of the cover plate, the electrode terminal 2 includes a first segment 26 and a second segment 27. The first segment 26 is located outside the second segment 27. A first mounting hole 40 is provided on the first insulating member 4. The second segment 27 is interference-fitted with the first radial inner circumferential surface 43. The high temperature resistance of the first segment 26 is less than that of the second segment 27, satisfying: 0.15≤h / H≤0.9. Specifically, the first segment 26 is made of aluminum, and the second segment 27 is made of copper, as 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, the dimension H of the pressure plate 3 will be relatively large, which will cause the welding and fixing between the pressure plate 3 and the electrode terminal 2 to be not firm, affecting the connection strength between the electrode terminal 2 and the pressure plate 3, thus causing the cover plate 1 to fail to seal and hindering the 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 connecting the pressure plate 3 and the electrode terminal 2 will be too close to the first insulating component 4 and the second section 27 of copper material. The welding temperature will be directly or through the second section 27 of copper material to the first insulating component 4, which will easily cause the first insulating component 4 to soften, thus causing the insulation of the first insulating component 4 to fail.

[0070] The ratio h / H of the dimension h of the first protrusion 5 and the dimension H of the pressure plate 3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8. This ensures the connection strength and overcurrent capacity between the motor terminal and the pressure plate 3, while reducing damage to the first insulating component 4 during welding of the electrode terminal 2 and the pressure plate 3, and improving the sealing stability of the cover assembly.

[0071] Optionally, refer to Figure 4 There is a connecting interface 28 between the first segment 26 and the second segment 27. Along the thickness direction A of the cover plate, the minimum distance d between the first protrusion 5 and the connecting interface 28 satisfies: 0.5mm≤d≤3mm. Since the electrode terminal 2 and the pressure plate 3 are welded together at the first protrusion 5, if the minimum distance d between the first protrusion 5 and the connecting interface 28 is too small, the heat generated during the welding of the electrode terminal 2 and the pressure plate 3 will be transferred to the second segment 27, causing the copper material at the second end to melt. The molten copper will enter the weld between the electrode terminal 2 and the pressure plate 3, thus reducing the welding strength. If the minimum distance d between the first protrusion 5 and the connecting interface 28 is too large, it means that the aluminum material of the first segment 26 in the electrode terminal 2 has a large dimension along the thickness direction of the cover plate 1, while the proportion of copper material in the second segment 27 is too small, affecting the conductivity of the electrode terminal 2. Along the thickness direction A of the cover plate, the minimum distance d between the first protrusion 5 and the connection interface 28 can be 0.8mm, 1mm, 1.2mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.6mm, or 2.8mm. Therefore, it is necessary to ensure that the second section 27 of copper material at the connection interface 28 will not melt due to heat during the welding of the electrode terminal 2 and the pressure plate 3.

[0072] Optionally, refer to Figure 2 and Figure 4 The first insulating member 4 includes a first part 41 and a second part 42. Along the thickness direction A of the cover plate, the first part 41 is disposed between the pressure plate 3 and the cover plate 1, and the second part 42 is connected to the radial outer end of the first part 41 and covers at least a portion 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 part 41 is d2, which satisfies: 0.15≤d2 / d≤5.

[0073] Since the electrode terminal 2 and the pressure plate 3 are welded together at the first protrusion 5, the heat generated during the welding of the electrode terminal 2 and the pressure plate 3 will be transferred inward. If the ratio between the distance d2 from the first protrusion 5 to the first part 41 and the distance d between the first protrusion 5 and the connection interface 28 is too small, it means that the first part 41 of the first insulating member 4 is closer to the first protrusion 5, and the connection interface 28 is closer to the inward. In other words, the proportion of aluminum in the first segment 26 of the electrode terminal 2 is greater than that of copper in the second segment 27, which leads to poor conductivity of the electrode terminal 2. The heat generated during the conduction of aluminum is greater, which in turn makes the first insulating member 4 more susceptible to heat damage.

[0074] Optionally, the minimum distance d2 between the first protrusion 5 and the first part 41 satisfies: 0.5mm ≤ d2 ≤ 2.5mm. The minimum distance d2 between the first protrusion 5 and the first part 41 can be 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm or 2.5mm.

[0075] If the ratio of the distance d2 between the first protrusion 5 and the first part 41 to the distance d between the first protrusion 5 and the connecting interface 28 is too large, it indicates that the first part 41 of the first insulating member 4 is farther from the first protrusion 5, while the connecting interface 28 is closer to the first protrusion 5. In other words, the first insulating member 4 is more closely fitted to the copper material of the second segment 27 of the electrode terminal 2. Since copper has better thermal conductivity than aluminum, during the welding process between the electrode terminal 2 and the pressure plate 3, the welding heat from laser welding is easily transferred to the first insulating member 4 by the copper material of the second segment 27, causing heat damage to the first insulating member 4. At the same time, during the welding process between the electrode terminal 2 and the pressure plate 3, copper material is also easily mixed into the weld pool, resulting in a decrease in welding strength.

[0076] Therefore, the ratio d2 / d between the distance d2 from the first protrusion 5 to the first part 41 and the distance d between the first protrusion 5 and the connecting interface 28 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 regardless of whether the first protrusion 5 is located on the electrode terminal 2 or the pressure plate 3, the ratio d2 between the minimum distance d2 from the first protrusion 5 to the first part 41 and the minimum distance d between the first protrusion 5 and the connecting interface 28 must satisfy: 0.15 ≤ d2 / d ≤ 5.

[0077] Optionally, refer to Figure 2 and Figure 4 The first insulating element 4 includes a first part 41 and a second part 42. Along the thickness direction A of the cover plate, the first part 41 is disposed between the pressure plate 3 and the cover plate 1, and the second part 42 is connected to the radially outer end of the first part 41 and covers at least a portion of the radially 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 part 41 is d2, which must satisfy: 0.5mm≤d2≤2.5mm. Since the electrode terminal 2 and the pressure plate 3 are welded together at the first protrusion 5, if the minimum distance d2 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 pressure plate 3 can easily be transferred to the first part 41, causing the first insulating element 4 to be damaged by heat. The minimum distance d2 between the first protrusion 5 and the first part 41 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, regardless of whether the first protrusion 5 is located on the electrode terminal 2 or the pressure plate 3, the minimum distance d2 between the first protrusion 5 and the first part 41 must satisfy: 0.5mm≤d2≤2.5mm.

[0078] Secondly, refer to Figure 5 This application provides a single-cell battery, including a casing, an electrode assembly 71, a separator 72, and a cover assembly as described in any of the above embodiments. The cover assembly is connected to the casing to form a receiving chamber. The electrode assembly 71 is disposed in the receiving chamber and includes an electrode assembly 71 body and tabs 73. The tabs 73 are respectively connected to the electrode assembly 71 body and the electrode terminal 2. The separator 72 is disposed on the outside of the electrode assembly 71 body, and the tabs 73 pass through the separator 72 and are connected to the electrode assembly 71 body.

[0079] In the single-cell battery proposed in this application embodiment, the electrode terminal 2 and the pressure plate 3 are connected by the connecting peripheral 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 pressure plate 3. When the electrode terminal 2 and the pressure plate 3 are welded to the first protrusion 5, the heat of welding is shielded by the second protrusion 6, reducing the heat transferred to the first insulating component 4 during welding, thereby reducing the probability of damage to the first insulating component 4 and achieving the purpose of improving battery reliability. At the same time, the second protrusion 6 can also reduce the heat transferred to the separator 72 during welding, thereby alleviating the problem of separator 72 shrinkage.

[0080] Optionally, the first protrusion 5 has a first outer end face 51, a second outer end face 52, and a connecting peripheral surface 53 connecting the first outer end face 51 and the second outer end face 52. The connecting peripheral surface 53 is parallel to the thickness direction A of the cover plate. Along the thickness direction A of the cover plate, the projection of the tab 73 and the projection of the connecting peripheral surface 53 at least partially coincide.

[0081] Electrode terminal 2 is welded to pressure plate 3 at connection peripheral surface 53. Along the thickness direction A of cover plate, the projection of electrode tab 73 on cover plate 1 and the projection of connection peripheral surface 53 on cover plate 1 at least partially coincide, so that electrode tab 73 can block the cell, reduce the heat generated when electrode terminal 2 and pressure plate 3 are welded to diaphragm 72, and reduce the shrinkage of diaphragm 72.

[0082] 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 pressure 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 will be 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.

[0083] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0084] In some embodiments, the battery can be a battery pack, which includes a battery housing and individual battery cells, with the individual battery cells or battery modules housed within the battery housing.

[0085] In some embodiments, the battery cell can be a rechargeable battery, which refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used. The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0086] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0088] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0089] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that, include: Cover plate; Electrode terminals; A pressure plate is disposed on the outside of the cover plate. The pressure plate is connected to the electrode terminal. Along the thickness direction of the cover plate, the projection of the pressure plate at least partially coincides with the projection of the cover plate. as well as A first insulating member, at least a portion of which is disposed between the pressure plate and the cover plate, the first insulating member having a first radial inner circumferential surface that abuts against the electrode terminal; In this configuration, 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. 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. 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 outside the second protrusion. At least a portion of the projection of the first protrusion overlaps with the projection of the second protrusion. The projection of the first weld does not overlap with the projection of the first radial inner circumferential surface. 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: 0.5mm≤h≤2mm, 0.5mm≤h1≤2mm, 0≤h-h1≤1.5mm.

2. The cover plate assembly according to claim 1, characterized in that, Along the thickness direction of the cover plate, the size of the pressure plate is H, which satisfies: 1.5mm≤H≤3mm.

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

4. The cover plate assembly according to claim 1, characterized in that, The electrode terminal has a main body portion that is interference-fitted with the first radial inner circumferential surface. The outer end of the pressure plate and the outer end of the first protrusion both protrude from the outer end of the electrode terminal to form a second connection portion, which 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.

5. The cover plate assembly according to claim 4, characterized in that, The width W2 of the second connecting part satisfies: 2mm≤W2≤8mm, and the diameter D2 of the main body part satisfies: 10mm≤D2≤40mm.

6. The cover plate assembly according to claim 1, characterized in that, Along the thickness direction of the cover plate, the electrode terminal includes a first main body segment and a second main body segment, wherein the first main body segment is located outside the second main body segment; The outer diameter of the first main body segment is smaller than the outer diameter of the second main body segment to form a first stepped surface, and the second protrusion is disposed on the second main body segment and spaced apart from the first stepped surface in the thickness direction of the cover plate.

7. The cover plate assembly according to claim 6, characterized in that, Along the thickness direction of the cover plate, the outer end face of the first step, the outer end face of the first protrusion, and the outer end face of the pressure plate are flush.

8. The cover plate assembly according to claim 1, characterized in that, The first insulating member includes a first part and a second part. Along the thickness direction of the cover plate, the first part is disposed between the pressure plate and the cover plate, and the second part is connected to the radially outer end of the first part and covers at least a portion of the radially outer peripheral surface of the pressure plate. Along the radial direction of the electrode terminal, the distance between the second part and the radial inner circumferential surface of the first protrusion is d3, which satisfies: 2.5mm≤d3≤10mm.

9. 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 welded and fixed to the inner peripheral surface of the pressure plate.

10. The cover plate assembly according to claim 9, 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 pressure plate and the width of the second protrusion is W3, satisfying: 0.05≤W1 / W3≤0.

8.

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

12. The cover plate assembly according to claim 9, characterized in that, The first insulating member includes a first part and a second part. Along the thickness direction of the cover plate, the first part is disposed between the pressure plate and the cover plate, and the second part is connected to the radial outer end of the first part and covers at least a portion of the radial outer peripheral surface of the pressure plate. Along the radial direction of the electrode terminal, the distance between the second part and the radial outer peripheral surface of the first protrusion is d3, which satisfies: 2.5mm≤d3≤10mm.

13. 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 segment and a second segment. The first segment is located outside the second segment, and the second segment is interference-fitted with the first radial inner circumferential surface. The high temperature resistance of the first segment is less than that of the second segment.

14. The cover plate assembly according to claim 13, characterized in that, The first segment and the second segment have a connecting interface. Along the thickness direction of the cover plate, the minimum distance between the first protrusion and the connecting interface is d, which satisfies: 0.5mm≤d≤3mm.

15. The cover plate assembly according to claim 14, characterized in that, The first insulating member includes a first part and a second part. Along the thickness direction of the cover plate, the first part is disposed between the pressure plate and the cover plate, and the second part is connected to the radially outer end of the first part and covers at least a portion of the radially outer peripheral surface of the pressure plate. Along the thickness direction of the cover plate, the minimum distance between the first protrusion and the first part is d2, which satisfies: 0.15≤d2 / d≤5.

16. The cover plate assembly according to claim 15, characterized in that, The minimum distance d2 between the first protrusion and the first part satisfies: 0.5mm≤d2≤2.5mm.

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

18. A single-cell battery, characterized in that, include: case; The cover assembly according to any one of claims 1-17, wherein the cover assembly is connected to the housing to form a receiving chamber; An electrode assembly is disposed in the receiving chamber. The electrode assembly includes an electrode assembly body and electrode tabs, and the electrode tabs are respectively connected to the electrode assembly body and the electrode terminals. as well as A diaphragm is disposed on the outside of the electrode assembly body, and the tab passes through the diaphragm and is connected to the electrode assembly body.

19. The single-cell battery according to claim 18, characterized in that, in, The first protrusion has a first outer end face, a second outer end face, and a connecting peripheral surface connecting the first outer end face and the second outer end face. The connecting peripheral surface is parallel to the thickness direction of the cover plate. Along the thickness direction of the cover plate, the projection of the electrode lug at least partially coincides with the projection of the connecting peripheral surface.

20. The single-cell battery according to claim 19, 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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