A battery cover plate assembly and a battery

Abstract

The application relates to the technical field of batteries, and particularly discloses a battery cover plate assembly and a battery. The battery cover plate assembly comprises a connecting block and a pole. One end of the pole is riveted with a first step surface of a first sink of the connecting block after penetrating through the connecting block, the end of the pole riveted with the first step surface expands around to form a riveting part, a circumferential side wall of the riveting part and a first side wall of the first sink form a joint, and the joint of the two is welded to form a welding part. The diameter of the riveting part is d1, the distance between the center line of the welding part and the circumferential side wall of the riveting part is n, and the relationship between n and d1 satisfies 0.0125<=n / d1<=0.025. The welding structure between the pole and the connecting block is improved, the connecting strength between the pole and the connecting block is high, the overcurrent capacity is good, and the performance of the battery cover plate assembly is better. The application further provides a battery comprising the battery cover plate assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery cover plate assembly and a battery. BACKGROUND

[0002] In a lithium ion battery, the battery cover plate assembly is a key accessory, which is connected with the shell through the battery cover plate assembly to package the pole group in the shell, and the pole post on the battery cover plate assembly can lead out the positive and negative poles of the pole group to play a role of connecting the external circuit.

[0003] The existing battery cover plate assembly generally includes a connecting block, an upper plastic part, a pole post, a cover plate body, a lower plastic part and a sealing ring, the sealing ring is sleeved outside the pole post, the pole post passes through the lower plastic part, the cover plate body, the upper plastic part and the connecting block from one side of the cover plate body in turn, and then is riveted with the connecting block, and then the pole post is welded with the connecting block to increase the conductivity between the two, the pole post is fixedly installed on the cover plate body through riveting + welding, the sealing ring is located between the pole post and the cover plate body, and the gap between the pole post and the cover plate body is sealed through the sealing ring, and the upper plastic part and the lower plastic part are used for insulating and isolating the pole post and the cover plate body.

[0004] However, since the center line of the joint and the welding seam between the pole post and the connecting block completely coincide, the melting area of the pole post is large when the pole post is welded with the connecting block, the mechanical property of the welding seam position of the pole post after welding is lower than that of the remaining position of the pole post, the push-pull force that the pole post can withstand is reduced, and when the pole post is knocked or impacted, the pole post is easily separated from the connecting block, thereby causing a short circuit risk and battery failure. If the pole post and the connecting block are only riveted without welding, the resistance value between the pole post and the connecting block is large, and the heating condition is serious, and the internal resistance of the battery is increased. SUMMARY

[0005] The purpose of the present application is to provide a battery cover plate assembly and a battery, which can ensure that the connection strength between the pole post and the connecting block is high under the condition that the resistance value between the pole post and the connecting block is small, and the pole post and the connecting block can withstand a large push-pull force, and the connection between the pole post and the connecting block is reliable and stable.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] On the one hand, the present application provides a battery cover plate assembly, which comprises:

[0008] The connecting block is provided with a first mounting hole, and a first sink table is arranged on the inner wall of the first mounting hole, and the first sink table comprises a first step surface and a first side wall;

[0009] A pole is riveted at one end of the first mounting hole after passing through the first mounting hole and abutting against the first step surface, the riveted end of the pole and the first step surface is expanded to form a riveted portion along the radial direction of the first mounting hole, the circumferential wall of the riveted portion is welded to the first side wall to form a welded portion between the riveted portion and the first side wall, the riveted portion, the first counterbore, and the welded portion are coaxial with the first mounting hole;

[0010] The diameter of the riveted portion is d1, the diameter of the center line of the welded portion is d2, and the distance between the center line of the welded portion and the circumferential wall of the riveted portion is n.

[0011] The relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n= (d2-d1) / 2.

[0012] Optionally, along the radial direction of the first mounting hole, the fusion width of the welded portion is w, and w is in the range of: 0.5mm≤w≤1.0mm.

[0013] And / or, along the axial direction of the first mounting hole, the fusion depth of the welded portion is h, and h is in the range of: 0.3mm≤h≤0.5mm.

[0014] Optionally, a second counterbore is arranged on the inner wall of the first mounting hole, and the second counterbore is located close to the port of the first mounting hole relative to the first counterbore, the second counterbore comprises a second step surface and a second side wall, and the second step surface is adjacent to the first side wall of the first counterbore.

[0015] Optionally, along the axial direction of the first mounting hole, the height difference between the first step surface and the second step surface is S1, and S1 is in the range of: S1≥1.0mm.

[0016] Optionally, along the axial direction of the first mounting hole, the height of the riveted portion is X, and the relationship between X and S1 satisfies: 0mm≤S1-X≤0.2mm.

[0017] Optionally, along the axial direction of the first mounting hole, the height difference between the second step surface and the end surface of the side of the second counterbore provided with the second counterbore of the connecting block is S2.

[0018] S2 is in the range of: 0.1mm≤S2≤1.0mm.

[0019] Optionally, along the axial direction of the first mounting hole, the distance between the top of the welded portion and the second step surface is e, and e is in the range of: 0mm≤e≤0.1mm.

[0020] Optionally, the battery cover plate assembly further comprises a cover plate body provided with a second mounting hole, the pole post is riveted with the first step surface of the first sink after passing through the second mounting hole and the first mounting hole.

[0021] Optionally, the pole post comprises a plate body part, a first post body part and a second post body part connected in sequence, the second post body part is riveted with the first step surface of the first sink after passing through the second mounting hole and the first mounting hole, the plate body part is located on the side of the cover plate body away from the riveting part, the first post body part is arranged in the second mounting hole, and the second post body part is arranged in the first mounting hole.

[0022] The pre-assembly gap f between the circumferential wall of the second post body part and the inner wall of the first mounting hole is 0.05mm≤f≤0.15mm.

[0023] In another aspect, the present application provides a battery comprising the battery cover plate assembly in any of the above-mentioned schemes.

[0024] The present application has the following beneficial effects:

[0025] The present application provides a battery cover plate assembly comprising a connecting block and a pole post. The connecting block is provided with a first mounting hole, and the inner wall of the first mounting hole is provided with a first sink. One end of the pole post is riveted with the first step surface of the first sink after passing through the connecting block. The end of the pole post riveted with the first step surface expands to form a riveting part. The circumferential wall of the riveting part is welded with the first side wall of the first sink to form a welding part. The riveting part, the first sink and the welding part are coaxial with the first mounting hole. The diameter of the riveting part is d1, the diameter of the center line of the welding part is d2, and the distance between the center line of the welding part and the circumferential wall of the riveting part is n. The relationship between n and d1 satisfies 0.0125≤n / d1≤0.025, and n=(d2-d1) / 2. By improving the welding structure between the pole post and the connecting block, the diameter of the center line of the welding part is expanded, so that the connection strength between the pole post and the connecting block is higher, and the resistance value between the pole post and the connecting block is smaller, which meets the overcurrent requirement of the pole post, and the performance of the battery cover plate assembly is good.

[0026] The present application also provides a battery comprising the above-mentioned battery cover plate assembly. By using the battery cover plate assembly, the resistance value between the pole post and the connecting block can be reduced, and the conductivity is good when the pole post is connected with the external circuit, so that the heating problem of the battery cover plate assembly during charging and discharging is alleviated. At the same time, the connection strength between the pole post and the connecting block is higher, and the pole post and the connecting block can withstand larger push-pull stress, so that the assembly structure of the battery cover plate assembly is stable and reliable, and is not easy to fail. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present application and these drawings without any creative effort.

[0028] Figure 1 An exploded view of the battery cover plate assembly provided in the embodiments of the present application;

[0029] Figure 2 A top view of the battery cover plate assembly provided in the embodiments of the present application;

[0030] Figure 3 A Figure 2 sectional view of A-A in the figure;

[0031] Figure 4 A Figure 3 enlarged view of B in the figure.

[0032] In the figure:

[0033] 100, cover plate body; 110, second mounting hole; 111, limiting step;

[0034] 200, connecting block; 210, first mounting hole; 211, first sink; 2111, first step surface; 2112, first side wall; 212, second sink; 2121, second step surface; 2122, second side wall;

[0035] 300, pole; 310, plate body part; 320, first column part; 321, support table; 330, second column part; 331, riveting part; 332, welding part;

[0036] 400, first plastic part; 410, third mounting hole; 420, accommodating groove; 430, annular flange; 500, second plastic part; 510, fourth mounting hole; 600, sealing part. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application as claimed, but merely represents selected embodiments of the application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the application without creative labor fall within the scope of protection of the application.

[0039] It should be noted that similar reference numbers and letters refer to similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0040] In the description of the application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the application is usually placed, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0041] In the description of the application, it should also be noted that, unless otherwise specified and limited, the terms "provided", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected. For those of ordinary skill in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "over", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0043] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] like Figures 1-4 As shown, this embodiment provides a battery cover assembly, which includes a connecting block 200 and a terminal post 300. The connecting block 200 is provided with a first mounting hole 210, and the inner wall of the first mounting hole 210 is provided with a first recessed platform 211, which includes a first stepped surface 2111 and a first sidewall 2112.

[0045] At least a portion of the pole post 300 is a columnar structure. The first mounting hole 210 is a circular hole. One end of the pole post 300, which is columnar, passes through the first mounting hole 210 and is riveted to the first stepped surface 2111 of the first recess 211. The end of the pole post 300 riveted to the first stepped surface 2111 expands along the radial direction of the first mounting hole 210 to form a riveting portion 331. By setting at least a portion of the pole post 300 to a columnar structure, the pole post 300 can expand evenly in all directions when riveted to the first stepped surface 2111, thereby improving the uniformity of force on the pole post 300 and the connecting block 200. Furthermore, after the pole post 300 and the connecting block 200 are riveted together, a riveting part 331 is formed. The end face of the riveting part 331 facing the connecting block 200 abuts against the first step surface 2111. The peripheral side wall of the riveting part 331 abuts against the first side wall 2112 of the first recess 211, and a joint is formed between the peripheral side wall of the riveting part 331 and the first side wall 2112. By welding at the joint between the peripheral side wall of the riveting part 331 and the first side wall 2112, a welding part 332 is formed between the riveting part 331 and the first side wall 2112. The riveting part 331, the first recess 211, and the welding part 332 are all coaxial with the first mounting hole 210.

[0046] It should be noted that in this embodiment, the center line of the welded part 332 is along the radial direction of the first mounting hole 210. Figure 1The X-axis and Y-axis directions shown in the diagram expand outwards. Therefore, when the riveted portion 331 of the electrode post 300 is welded to the first sidewall 2112, most of the molten pool formed by the weld portion 332 due to heat is located on the first sidewall 2112 of the first recess 211. The volume of the electrode post 300 molten by heat is reduced, thereby reducing the impact of welding on the mechanical strength of the electrode post 300. While ensuring a low resistance value between the electrode post 300 and the connecting block 200, the connection strength between the electrode post 300 and the connecting block 200 is high. When the electrode post 300 is fixed, the connecting block 200 can withstand a large pushing and pulling force (≥1000N), and the electrode post 300 is not easily deformed during this process. The weld portion 332 between the electrode post 300 and the connecting block 200 is also less prone to cracking, resulting in high reliability of the battery cover assembly. It should be noted that the weld portion 332 is generally annular, and the center line of the weld portion 332 is the circle formed by the midpoints of the weld portion 332 along the radial direction of the first mounting hole 210.

[0047] Optionally, see [link to relevant documentation] Figure 3 and Figure 4 In this embodiment, the diameter of the riveting part 331 is d1, and the diameter of the centerline of the welding part 332 is d2. Since the peripheral sidewall of the riveting part 331 abuts against the first sidewall 2112 of the first recessed platform 211, the diameter of the joint between the peripheral sidewall of the riveting part 331 and the first sidewall 2112 of the first recessed platform 211 is also d1. The distance between the centerline of the welding part 332 and the peripheral sidewall of the riveting part 331 is n. The relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2. For example, the value of n can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm or 0.2mm, etc., and the value of n / d1 can be 0.0125, 0.0130, 0.0150, 0.0180, 0.0200 or 0.0250, etc. When the distance n between the center line of the welding part 332 and the peripheral sidewall of the riveting part 331 is within the above range, and the relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, the connecting block 200 can withstand a push-pull force of more than 1000N, the connection between the terminal post 300 and the connecting block 200 is reliable and stable, and the resistance between the terminal post 300 and the connecting block 200 is less than or equal to 0.035mΩ, which meets the overcurrent requirement of the terminal post 300, and the battery cover assembly performs well.

[0048] Furthermore, along the radial direction of the first mounting hole 210, the weld width of the welded portion 332 is w, and the value of w ranges from 0.5mm ≤ w ≤ 1.0mm. For example, the value of w can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1.0mm, etc. Along the axial direction of the first mounting hole 210 ( Figure 3The depth of the welding portion 332 is h (in the Z-axis direction shown in the figure), and h is in the range of 0.3mm≤h≤0.5mm. For example, h can be 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, etc. By limiting the width w and the depth h of the welding portion 332, the molten pool formed when the pole 300 is welded to the connecting block 200 is ensured to be large enough, which can ensure that the welding strength between the pole 300 and the connecting block 200 is high, the welding quality is good, the connection between the two is reliable and stable, and the conductivity is good. Otherwise, when the width w is small and the depth h is shallow, it is easy to cause the welding strength between the pole 300 and the connecting block 200 to be insufficient, and the welding portion 332 between the pole 300 and the connecting block 200 is easy to crack, and the assembly reliability is reduced. In addition, the width w should not be too large, otherwise the molten volume of the pole 300 during welding will be too large, which will cause the mechanical strength of the pole 300 to decrease, and the pole 300 is easy to deform or break; the depth h should not be too large, otherwise there is a risk of welding through the connecting block 200 during welding, which will cause the battery cover plate assembly to be scrapped.

[0049] Continuing to refer to Figure 3 and Figure 4 In the embodiment, the inner wall of the first mounting hole 210 is further provided with a second sunken platform 212, which is located close to the port of the first mounting hole 210 relative to the first sunken platform 211. The second sunken platform 212 is coaxial with the first sunken platform 211, and the diameter of the second sunken platform 212 in the radial direction of the first mounting hole 210 is greater than that of the first sunken platform 211. The second sunken platform 212 includes a second stepped surface 2121 adjacent to the first side wall 2112 of the first sunken platform 211, and a second side wall 2122 adjacent to the end surface of the connecting block 200 on the side where the second sunken platform 212 is provided. By providing the second sunken platform 212, the riveting portion 331 and the welding portion 332 can be located below the end surface of the connecting block 200 on the side where the second sunken platform 212 is provided, which has a good protective effect on the connection position of the pole 300 and the connecting block 200, reduces the risk of hole and point explosion of the welding portion 332, and helps to improve the flatness of the connecting block 200, meets the requirement of the battery cover plate assembly for surface flatness, and has high dimensional accuracy.

[0050] Further, along the axial direction of the first mounting hole 210, the height difference between the first step surface 2111 and the second step surface 2121 is S1, and the value range of S1 is: S1≥1.0mm. For example, the value of S1 can be 1.0mm, 2.0mm, 3.0mm, etc. Along the axial direction of the first mounting hole 210, the height of the riveting portion 331 is X, and the relationship between X and S1 satisfies: 0mm≤S1-X≤0.2mm. For example, the value of S1-X can be 0mm, 0.05mm, 0.1mm, 0.15mm or 0.2mm, etc. By adopting the above size limit, the end of the riveting portion 331 along the axial direction of the first mounting hole 210 will not exceed the first side wall 2112 of the first sink 211, facilitating the welding operation, and the riveting portion 331 and the welding portion 332 can be protected to some extent, avoiding direct impact on the riveting portion 331 and the welding portion 332.

[0051] Along the axial direction of the first mounting hole 210, the height difference between the second step surface 2121 and the end surface of the side of the connecting block 200 provided with the second sink 212 is S2, and the value range of S2 is: 0.1mm≤S2≤1.0mm. For example, the value of S2 can be 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm or 1.0mm, etc. By adopting the above size setting, the welding portion 332 and the riveting portion 331 will not protrude from the end surface of the side of the connecting block 200 provided with the second sink 212, which is beneficial to protect the connection position therebetween, and the height difference between the second step surface 2121 and the end surface of the side of the connecting block 200 provided with the second sink 212 is small, facilitating the welding operation between the riveting portion 331 and the first side wall 2112. Otherwise, when the height difference between the second step surface 2121 and the end surface of the side of the connecting block 200 provided with the second sink 212 is large, the welding is difficult and inconvenient to operate, and the space in the axial direction of the first mounting hole 210 is also wasted, which is not conducive to reducing the thickness of the battery cover plate assembly and the energy density of the battery is low.

[0052] Further, along the axial direction of the first mounting hole 210, the distance between the top of the welding portion 332 and the second step surface 2121 is e, and the value range of e is: 0mm≤e≤0.1mm. For example, the value of e can be 0mm, 0.02mm, 0.04mm, 0.06mm, 0.08mm or 0.1mm, etc. In this way, the welding portion 332 is prevented from protruding from the end surface of the side of the connecting block 200 provided with the second sink 212, while reducing the risk of hole or point explosion of the welding portion 332.

[0053] Continuing to refer to Figure 1 , Figure 3 and Figure 4The battery cover plate assembly in the embodiment further comprises a cover plate body 100 provided with a second mounting hole 110, one end of the pole 300 in a columnar structure passes through the second mounting hole 110 and the first mounting hole 210 and is riveted with the first step surface 2111 of the first sunken platform 211.

[0054] Optionally, the pole 300 in the embodiment comprises a plate body part 310, a first columnar part 320 and a second columnar part 330 connected in sequence, wherein the plate body part 310 is arranged on the side of the cover plate body 100 away from the connecting block 200, the second columnar part 330 passes through the second mounting hole 110 and the first mounting hole 210 in sequence and is riveted with the first step surface 2111 of the first sunken platform 211, and one end of the second columnar part 330 riveted with the first step surface 2111 is expanded in the radial direction of the first mounting hole 210 to form the riveted part 331. After the pole 300 is assembled with the connecting block 200 and the cover plate body 100, the first columnar part 320 is arranged in the second mounting hole 110 and the second columnar part 330 is arranged in the first mounting hole 210. The riveted part 331 and the plate body part 310 press the cover plate body 100 from both sides of the cover plate body 100 respectively, so as to fix the connecting block 200 and the pole 300 on the cover plate body 100, and the connection between the pole 300 and the cover plate body 100 is reliable and stable.

[0055] In addition, the diameter of the first columnar part 320 of the pole 300 is greater than the diameter of the second columnar part 330, and a transition support platform 321 is formed between the peripheral side wall of the first columnar part 320 and the peripheral side wall of the second columnar part 330, which can support the end surface of the connecting block 200 close to the cover plate body 100, so that the connecting block 200 can be well supported when the pole 300 is riveted with the connecting block 200, which is conducive to improving the yield of riveting and improving the flatness of the connecting block 200.

[0056] Further, the second cylindrical portion 330 in the embodiment has a pre-assembly gap f between the circumferential wall and the inner wall of the first mounting hole 210, and the value of f is in the range of 0.05mm≤f≤0.15mm. For example, the value of f can be 0.05mm, 0.1mm or 0.15mm, etc. By setting the pre-assembly gap f between the circumferential wall of the second cylindrical portion 330 and the inner wall of the first mounting hole 210, on the one hand, the second cylindrical portion 330 is easily installed into the first mounting hole 210, and a certain limiting effect is provided for the pole column 300, so as to ensure the positioning accuracy between the pole column 300 and the connecting block 200; on the other hand, the pre-assembly gap f also provides space for the radial expansion of the second cylindrical portion 330 along the first mounting hole 210, so as to avoid that the stress between the second cylindrical portion 330 and the connecting block 200 is too large when the pole column 300 is riveted with the connecting block 200, and the connecting block 200 is cracked or deformed. Of course, the value of the above-mentioned pre-assembly gap f should not be too small, otherwise the connecting block 200 is easily cracked or deformed when the pole column 300 is riveted with the connecting block 200, and the assembly effect is poor. The value of the above-mentioned pre-assembly gap f should not be too large, otherwise the positioning effect between the pole column 300 and the connecting block 200 is poor, the assembly precision is reduced, and after the pole column 300 is riveted with the connecting block 200, due to the large pre-assembly gap f, there is still a gap between the circumferential wall of the second cylindrical portion 330 and the inner wall of the first mounting hole 210, the contact area between the pole column 300 and the connecting block 200 is reduced, the conduction effect is reduced, the resistance value between the pole column 300 and the connecting block 200 is increased, and the internal resistance of the battery is increased.

[0057] Continuing to refer to Figure 1 , Figure 3 and Figure 4The battery cover plate assembly in the embodiment further comprises a first plastic part 400, a second plastic part 500 and a sealing part 600. The first plastic part 400 is arranged on the side of the cover plate body 100 away from the plate body part 310 of the pole 300. The second plastic part 500 is arranged on the side of the cover plate body 100 close to the plate body part 310 of the pole 300. The first plastic part 400 is provided with a third mounting hole 410. The second plastic part 500 is provided with a fourth mounting hole 510. The second column part 330 of the pole 300 is connected with the connecting block 200 after sequentially penetrating through the fourth mounting hole 510, the second mounting hole 110, the third mounting hole 410 and the first mounting hole 210. The first column part 320 of the pole 300 penetrates through the fourth mounting hole 510, the second mounting hole 110 and the third mounting hole 410. The second column part 330 of the pole 300 penetrates through the first mounting hole 210. In the axial direction of the first mounting hole 210, the riveting part 331 of the pole 300 presses the connecting block 200 and the first plastic part 400 against one end surface of the cover plate body 100. The first plastic part 400 is clamped between the connecting block 200 and the cover plate body 100, and the connecting block 200 and the cover plate body 100 are insulated by the first plastic part 400. In the axial direction of the first mounting hole 210, the plate body part 310 of the pole 300 presses the second plastic part 500 against the other end surface of the cover plate body 100. The second plastic part 500 is clamped between the plate body part 310 and the cover plate body 100, and the pole 300 and the cover plate body 100 are insulated by the second plastic part 500. The sealing part 600 is sleeved on the first column part 320 of the pole 300, and the sealing part 600 is clamped between the circumferential wall of the first column part 320 and the inner wall of the second mounting hole 110. The gap between the pole 300 and the cover plate body 100 is sealed by the sealing part 600, and the pole 300 and the cover plate body 100 are insulated.

[0058] Further, the side of the first plastic part 400 away from the cover plate body 100 is provided with a containing groove 420, and at least part of the connecting block 200 is embedded in the containing groove 420. By arranging the containing groove 420, on the one hand, the positioning accuracy between the connecting block 200 and the first plastic part 400 can be improved, and the assembly between the two can be ensured to be good; on the other hand, the thickness of the battery cover plate assembly in the axial direction of the first mounting hole 210 (i.e. the Z-axis direction shown in the figure) can be reduced, which is beneficial to improve the energy density of the battery. Figure 3

[0059] ​Optionally, a pre-assembly gap b is provided between the peripheral sidewall of the connecting block 200 and the inner wall of the receiving groove 420, wherein the value of b is in the range of 0.3mm ≤ b ≤ 0.5mm. For example, the value of b can be 0.3mm, 0.4mm, or 0.5mm, etc. By providing a pre-assembly gap b between the peripheral sidewall of the connecting block 200 and the inner wall of the receiving groove 420, on the one hand, the connecting block 200 is easily installed into the receiving groove 420, and a certain limiting effect is provided for the connecting block 200 to ensure accurate positioning between the first plastic part 400 and the connecting block 200; on the other hand, the pre-assembly gap b is also the radial direction of the connecting block 200 along the first mounting hole 210 ( Figure 3 The expansion of the material (in the Y-axis direction shown in the diagram) provides space to prevent excessive stress between the first plastic part 400 and the connecting block 200 when the terminal post 300 and the connecting block 200 are riveted, which could lead to cracking or deformation of the first plastic part 400. Of course, the value of the aforementioned pre-assembly gap b should not be too small; otherwise, the first plastic part 400 is prone to cracking or deformation when the terminal post 300 and the connecting block 200 are riveted, resulting in poor assembly. The aforementioned pre-assembly gap b should also not be too large; otherwise, the positioning effect between the first plastic part 400 and the connecting block 200 will be poor, assembly accuracy will decrease, and after the terminal post 300 and the connecting block 200 are riveted, due to the large pre-assembly gap b, a gap will remain between the peripheral sidewall of the connecting block 200 and the inner wall of the receiving groove 420, making the connecting block 200 prone to loosening and resulting in low assembly strength of the battery cover assembly.

[0060] Optionally, an annular flange 430 is provided on the side of the first plastic part 400 near the cover plate body 100, and a limiting step 111 is provided on the side of the cover plate body 100 near the first plastic part 400. The limiting step 111 is located circumferentially to the second mounting hole 110 and coaxial with the second mounting hole 110. The annular flange 430 and the limiting step 111 cooperate to ensure accurate positioning between the first plastic part 400 and the cover plate body 100, which helps to improve the assembly accuracy between the first plastic part 400 and the cover plate body 100 and achieves a higher assembly yield. More preferably, one end of the sealing member 600 can extend into the third mounting hole 410 of the first plastic part 400, thereby sealing the gap between the first column portion 320 of the electrode post 300 and the inner wall of the third mounting hole 410, resulting in a better sealing effect of the battery cover plate assembly.

[0061] This embodiment also provides a battery, including a housing, an electrode assembly, and the aforementioned battery cover assembly. The housing has an opening on one side, through which the electrode assembly is installed into the housing, and the battery cover assembly is encapsulated within the opening of the housing. The electrode tabs of the electrode assembly are connected to the plate portion 310 of the terminal post 300 of the battery cover assembly, connecting the electrode assembly to an external circuit via the terminal post 300.

[0062] By adopting the battery cover plate assembly in the embodiment, the resistance value between the pole post 300 and the connecting block 200 can be reduced, the conductive effect is good when the pole post 300 is connected with the external circuit, the heating problem of the battery cover plate assembly during charging and discharging is alleviated, and the internal resistance of the battery is smaller. Meanwhile, the mechanical strength of the pole post 300 itself is higher, the pole post 300 and the connecting block 200 can withstand larger push-pull stress, the welding portion 332 is not easy to crack, the connection strength between the pole post 300 and the connecting block 200 is high, the assembly structure of the battery cover plate assembly is stable and reliable, and the battery is not easy to fail.

[0063] The push-pull force test and the resistance value test are performed on the samples after the pole post 300 and the connecting block 200 and the cover plate body 100 of different diameters are assembled.

[0064] The push-pull force test includes: fixing the pole post 300 and the cover plate body 100, applying a pulling force away from the cover plate body 100 or a pushing force toward the cover plate body 100 to the connecting block 200, when the welding portion 332 between the pole post 300 and the connecting block 200 cracks or the resistance value between the pole post 300 and the connecting block 200 changes, the maximum value of the push-pull force that the pole post 300 and the connecting block 200 can withstand at this moment is the push-pull force listed in Tables 1, 2 and 3.

[0065] The resistance value test includes: connecting one detection end of the resistance meter to the plate body portion 310 of the pole post 300, and connecting the other detection end of the resistance meter to the connecting block 200, so that the resistance value between the pole post 300 and the connecting block 200 can be measured by the resistance meter, that is, the resistance value listed in Tables 1, 2 and 3.

[0066] Specifically, when the diameter d1 of the riveting portion 331 of the pole post 300 is 8 mm, the test results of the maximum value of the push-pull force that the pole post 300 and the connecting block 200 can withstand and the resistance value between the pole post 300 and the connecting block 200 after adjusting the diameter d2 of the center line of the welding portion 332 are given in Table 1.

[0067] Table 1

[0068]

[0069] From the results in Table 1, it can be seen that in Comparative Example 1 and Comparative Example 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025, at this time, the push-pull force that the pole post 300 and the connecting block 200 can withstand is less than 1000N, which cannot meet the requirement of the assembly strength of the battery cover plate assembly, and in Comparative Example 1 and Comparative Example 2, the pole post 300 may also be deformed, resulting in insufficient compression force of the sealing element 600, easy sealing failure of the battery cover plate assembly, and unqualified battery cover plate assembly.

[0070] In the comparative example 3 and the comparative example 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025, at this time, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, but the resistance value between the pole post 300 and the connecting block 200 is greater than 0.035mΩ, the conductivity is poor, the battery cover plate assembly is easy to heat during battery charging and discharging, and the internal resistance of the battery is increased, the overcurrent capacity cannot meet the needs, and the battery cover plate assembly is unqualified.

[0071] In the embodiment 1, the embodiment 2, the embodiment 3, the embodiment 4, the embodiment 5 and the embodiment 6, the value of n / d1 is within the range of 0.0125≤n / d1≤0.025, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, the reliability of the battery cover plate assembly is high, and the resistance value between the pole post 300 and the connecting block 200 is less than 0.035mΩ, the conductivity is good, the battery cover plate assembly is not easy to heat during battery charging and discharging, the internal resistance of the battery is small, the overcurrent capacity meets the needs, and the battery cover plate assembly is qualified.

[0072] The test results of the maximum push-pull force that can be borne between the pole post 300 and the connecting block 200, and the resistance value between the pole post 300 and the connecting block 200 are given in Table 2 when the diameter d1 of the riveting part 331 of the pole post 300 is 10mm, and the diameter d2 of the center line of the welding part 332 is adjusted.

[0073] Table 2

[0074]

[0075] It can be seen from the results in Table 2 that in the comparative example 1 and the comparative example 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025, at this time, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is less than 1000N, which cannot meet the requirement of the battery cover plate assembly for assembly strength, the reliability of the battery cover plate assembly is not high, and the battery cover plate assembly is unqualified.

[0076] In the comparative example 3 and the comparative example 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025, at this time, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, but the resistance value between the pole post 300 and the connecting block 200 is greater than 0.035mΩ, the conductivity is poor, the battery cover plate assembly is easy to heat during battery charging and discharging, and the internal resistance of the battery is increased, the overcurrent capacity cannot meet the needs, and the battery cover plate assembly is unqualified.

[0077] In Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, the value of n / d1 is in the range of 0.0125≤n / d1≤0.025, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, the reliability of the battery cover plate assembly is high, and the resistance value between the pole post 300 and the connecting block 200 is less than 0.035mΩ, the conductivity is good, the battery cover plate assembly is not easy to heat during battery charging and discharging, the internal resistance of the battery is small, the overcurrent capacity meets the needs, and the battery cover plate assembly is qualified.

[0078] The test results of the maximum push-pull force that can be borne between the pole post 300 and the connecting block 200 and the resistance value between the pole post 300 and the connecting block 200 are given in Table 3 when the diameter d1 of the riveting part 331 of the pole post 300 is 11mm and the diameter d2 of the center line of the welding part 332 is adjusted.

[0079] Table 3

[0080]

[0081] As can be seen from the results in Table 3, in Comparative Example 1 and Comparative Example 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025, at this time the push-pull force that can be borne between the pole post 300 and the connecting block 200 is less than 1000N, which cannot meet the requirement of the battery cover plate assembly for assembly strength, the reliability of the battery cover plate assembly is low, and the battery cover plate assembly is unqualified.

[0082] In Comparative Example 3 and Comparative Example 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025, at this time the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, but the resistance value between the pole post 300 and the connecting block 200 is greater than 0.035mΩ, the conductivity is poor, the battery cover plate assembly is easy to heat during battery charging and discharging, and the internal resistance of the battery is increased, which cannot meet the needs of the overcurrent capacity, and the battery cover plate assembly is unqualified.

[0083] In Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, the value of n / d1 is in the range of 0.0125≤n / d1≤0.025, the push-pull force that can be borne between the pole post 300 and the connecting block 200 is greater than 1000N, which meets the requirement of the battery cover plate assembly for assembly strength, the reliability of the battery cover plate assembly is high, and the resistance value between the pole post 300 and the connecting block 200 is less than 0.035mΩ, the conductivity is good, the battery cover plate assembly is not easy to heat during battery charging and discharging, the internal resistance of the battery is small, the overcurrent capacity meets the needs, and the battery cover plate assembly is qualified.

[0084] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manners of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the implementation manners. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A battery cover assembly, characterized in that, include: The connecting block is provided with a first mounting hole, and a first recessed platform is provided on the inner wall of the first mounting hole. The first recessed platform includes a first stepped surface and a first side wall. The pole post has one end passing through the first mounting hole and riveted to the first stepped surface. The end of the pole post riveted to the first stepped surface expands along the radial direction of the first mounting hole to form a riveting part. The peripheral sidewall of the riveting part is welded to the first sidewall to form an annular welded part between the riveting part and the first sidewall. The riveting part, the first countersunk plate, and the welded part are all coaxial with the first mounting hole. Wherein, the center line of the welded part expands outward along the radial direction of the first mounting hole; the diameter of the riveting part is d1; the center line of the welded part is the circle formed by the midpoint of the welded part along the radial direction of the first mounting hole; the diameter of the center line of the welded part is d2; and the distance between the center line of the welded part and the peripheral sidewall of the riveting part is n. The relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2; The battery cover assembly further includes a cover body and a first plastic part. The first plastic part is sandwiched between the connecting block and the cover body. The cover body is provided with a second mounting hole. The first plastic part is provided with a third mounting hole. The second column portion of the pole passes through the second mounting hole, the third mounting hole, and the first mounting hole and is riveted to the first stepped surface of the first recessed platform. The first plastic part has a receiving groove on the side away from the cover plate body. At least a portion of the connecting block is embedded in the receiving groove. There is a pre-assembly gap b between the peripheral sidewall of the connecting block and the inner wall of the receiving groove. The value of b is in the range of 0.3mm≤b≤0.5mm. An annular flange is provided on the side of the first plastic part near the cover plate body, and a limiting step is provided on the side of the cover plate body near the first plastic part. The annular flange cooperates with the limiting step. Along the radial direction of the first mounting hole, the weld width of the welded portion is w; The value range of w is: 0.5mm≤w≤1.0mm; And / or, along the axial direction of the first mounting hole, the weld penetration depth is h; The value range of h is: 0.3mm ≤ h ≤ 0.5mm; With the pole fixed, the connecting block can withstand a push-pull force ≥1000N; The resistance between the pole and the connecting block is ≤0.035mΩ.

2. The battery cover assembly according to claim 1, characterized in that, A second recessed platform is provided on the inner wall of the first mounting hole, and the second recessed platform is located near the port of the first mounting hole relative to the first recessed platform. The second recessed platform includes a second stepped surface and a second side wall, and the second stepped surface is adjacent to the first side wall of the first recessed platform.

3. The battery cover assembly according to claim 2, characterized in that, Along the axial direction of the first mounting hole, the height difference between the first step surface and the second step surface is S1, and the value range of S1 is: S1≥1.0mm.

4. The battery cover assembly according to claim 3, characterized in that, Along the axial direction of the first mounting hole, the height of the riveted part is X, and the relationship between X and S1 satisfies: 0mm≤S1-X≤0.2mm.

5. The battery cover assembly according to claim 2, characterized in that, Along the axial direction of the first mounting hole, the height difference between the second stepped surface and the end face of the connecting block on the side with the second recessed platform is S2, and the value range of S2 is: 0.1mm≤S2≤1.0mm.

6. The battery cover assembly according to claim 2, characterized in that, Along the axial direction of the first mounting hole, the distance between the top of the welded part and the second step surface is e, and the value of e ranges from 0mm to e to 0.1mm.

7. The battery cover assembly according to claim 1, characterized in that, There is a pre-assembly gap f between the peripheral sidewall of the second column and the inner wall of the first mounting hole; The value of f is in the range of 0.05mm ≤ f ≤ 0.15mm.

8. A battery, characterized in that, Includes the battery cover assembly according to any one of claims 1-7.

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