Lithium ion battery top cover structure
Patent Information
- Application Number
- CN202521700651.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-11
- Publication Date
- 2026-09-15
- Estimated Expiration
- 2035-08-11
AI Technical Summary
虽然采用的是精密的激光焊接工艺，但只要是焊接工艺，难免出现爆点、孔洞，故现有顶盖结构的焊接工艺不仅增加工序，还造成优率的损失，会增加制造成本
1.由下往上的冲压形成装配部，装配部通过压铆形成台阶部，装配部的壁厚则减薄，由此，盖板、装配部与台阶部一体形成，省去焊接步骤，直接通过盖板制成装配部，将套好密封圈的极柱装配至安装孔，通过注塑将上塑胶注入装配部与极柱之间的空间中，弯折区能够防止上塑胶脱离极柱，限制整个极柱组件向上位移，装配部通过压铆形成台阶部，台阶部可抵住极柱组件和下塑胶下移，由此，装配部不需要焊接即可完成对极柱组件的固定，并且保证安装的密封性，不会导致顶盖优率的降低，也能够减少焊接的工序，使用更快速的旋铆来进行固定，节约生产成本。
Smart Images
Figure CN224759480U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and more specifically, to a top cover structure for a lithium-ion battery. Background Technology
[0002] Square aluminum-cased batteries mainly consist of three core components: the top cover, the aluminum casing, and the core. These components are cleverly assembled into a tight and safe structure through precise processes such as laser welding. The welding between the top cover and the casing ensures the overall sealing of the battery, thereby guaranteeing its stability and safety during use. The positive and negative terminals of the cell top cover play a crucial role in the square battery's top cover structure; they are not only responsible for current conduction but also directly affect the battery's structural stability and safety. The sealing of the assembly connection between the terminals and the top cover is also of paramount importance.
[0003] Currently, top covers are mainly divided into minimalist top covers and riveted top covers. However, to meet the increasing demands for cost reduction and reliability, the existing structures are no longer sufficient. Both types of top covers require an outer positioning ring to be welded to the top cover to secure the pole. Although a precision laser welding process is used, welding processes inevitably result in bursts and voids. Therefore, the welding process of existing top cover structures not only increases the number of steps but also leads to a loss of yield and increases manufacturing costs. Utility Model Content
[0004] The technical problem to be solved by this utility model is that the traditional top cover structure and electrode installation process will lead to increased processes and loss of yield. In view of the problems existing in the prior art, a lithium-ion battery top cover structure is provided.
[0005] The purpose and effects of this utility model are achieved by the following specific technical means: A lithium-ion battery top cover structure includes a cover plate and a lower plastic assembly fitted to the bottom of the top cover; The cover plate has a first surface and a second surface disposed opposite to the first surface, and the second surface faces downward. The first surface of the cover plate has a mounting hole that passes through the cover plate, and an electrode assembly is installed in the mounting hole. The inner wall of the mounting hole is formed into an assembly part by stamping, and the assembly part is formed into a stepped part by riveting. The cover plate, the assembly part and the stepped part are integrally formed. The outer wall of the assembly part is provided with a number of grooves, and the assembly part is limited to the pole assembly.
[0006] A further preferred embodiment: a mounting hole is provided at the center of the stepped portion; The electrode assembly includes an electrode, an upper plastic part, and a sealing ring. The electrode passes through the mounting hole and the lower plastic part. The sealing ring is disposed between the electrode and the mounting hole at the mounting position. The upper plastic part is disposed between the assembly part and the electrode.
[0007] A further preferred embodiment: the groove is a blind hole, and the assembly part is a retaining area and a bending area, wherein the retaining area bends inward with the top of the groove as the boundary to form the bending area.
[0008] A further preferred embodiment: a gap is provided between the enclosure area and the pole, and the upper plastic is located within the gap, and the upper plastic covers the enclosure area and the bending area.
[0009] A further preferred embodiment: the upper plastic penetrates into the groove, and the groove depth is ≥0.1mm.
[0010] A further preferred embodiment: the outer edge of the pole post is provided with a circumferential protrusion, and the outer end of the protrusion is provided with a sloping outward protrusion.
[0011] A further preferred embodiment: after the bending area is bent, a through hole is formed at the center, and the outer diameter of the protruding area is larger than the inner diameter of the through hole.
[0012] A further preferred embodiment: the upper plastic is engaged with the protruding area of the electrode post.
[0013] A further preferred embodiment: the first surface of the cover plate and the space between the mounting holes are provided with an explosion-proof hole and a liquid injection hole, the explosion-proof hole and the liquid injection hole penetrating through the cover plate.
[0014] The beneficial effects of this utility model are: 1. The assembly part is formed by stamping from bottom to top. The assembly part is then riveted to form a stepped part, and the wall thickness of the assembly part is reduced. Thus, the cover plate, assembly part and stepped part are formed as one piece, eliminating the welding step. The assembly part is directly formed by the cover plate. The pole with the sealing ring is assembled into the mounting hole. The upper plastic is injected into the space between the assembly part and the pole by injection molding. The bending area can prevent the upper plastic from detaching from the pole and limit the upward displacement of the entire pole assembly. The assembly part is riveted to form a stepped part, which can resist the downward movement of the pole assembly and the lower plastic. Thus, the assembly part can fix the pole assembly without welding and ensure the sealing of the installation. It will not lead to a decrease in the top cover yield and can also reduce the welding process. Faster riveting can be used for fixing, saving production costs. Attached Figure Description
[0015] The present invention will be further described below with reference to the accompanying drawings.
[0016] Figure 1 This is a schematic diagram showing the overall structure of this utility model broken down. Figure 2This is a partial schematic diagram of the top cover structure of this utility model (assembly part in unbent state). Figure 3 This is a partial schematic diagram of the top cover structure of this utility model (with the assembly part bent). Figure 4 This is a partial front view of the top cover structure of this utility model; Figure 5 This is a partial front view of the top cover structure of this utility model (assembly part in unbent state). Figure 6 This is a partial front view of the top cover structure of this utility model (with the assembly part bent). Figure 7 This is a front view of the overall structure of this utility model; Figure 8 This is a partial structural front view of the present invention.
[0017] Figures 1-8 In the middle: cover plate (1), mounting hole (101), assembly part (2), enclosure area (201), groove (202), bending area (203), step part (3), pole post (4), protrusion (401), sealing ring (5), upper plastic (6), lower plastic (7). Detailed Implementation
[0018] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely examples for implementing this utility model. It must be pointed out that the disclosed embodiments do not limit the scope of this utility model. On the contrary, any modifications and refinements made without departing from the scope of this utility model are within the patent protection scope of this utility model.
[0019] Please see Figure 1 and Figures 2-6 A lithium-ion battery top cover structure includes a cover plate 1 and a lower plastic 7 assembled at the bottom of the top cover. The cover plate 1 and the lower plastic 7 are connected by ultrasonic heat fusion. The cover plate 1 has a first surface and a second surface disposed opposite to the first surface, with the second surface facing the lower plastic 7. The first surface of the cover plate 1 has a mounting hole 101 that penetrates through the cover plate 1. Figure 4 The inner wall of the mounting hole 101 is formed into the assembly part 2 by punching from bottom to top, such as Figure 5 The assembly part 2 is formed into the stepped part 3 by riveting, and the wall thickness of the assembly part 2 is reduced. Thus, the cover plate 1, the assembly part 2 and the stepped part 3 are formed as one piece, eliminating the welding step, and the assembly part 2 is directly made through the cover plate 1.
[0020] Please see Figure 1 and Figure 8A mounting hole 101 is provided in the center of the stepped part 3. The pole post 4 assembly is installed in the mounting hole 101. The pole post 4 assembly includes the pole post 4, the upper plastic 6, and the sealing ring 5. The pole post 4 passes through the mounting hole 101 and the lower plastic 7. There are two mounting holes 101, namely the positive pole post hole and the negative pole post hole. The positive pole post assembly and the negative pole post assembly are installed in the mounting holes 101 respectively. The bottom of the pole post 4 can be welded to the metal connecting piece later. The metal connecting piece is the electrical transmission structure between the pole post 4 and the bare cell. The sealing ring 5 is compressed between the pole post 4 and the mounting position of the mounting hole 101. The sealing ring 5 can seal the mounting position of the pole post 4 and the mounting hole 101 to prevent loosening or even leakage.
[0021] Please see Figures 1-3 and Figures 7-8 When assembling the pole post 4 assembly, first, the sealing ring 5 is fitted onto the pole post 4, and then the pole post 4 with the sealing ring 5 fitted is assembled into the mounting hole 101. The pole post 4 will pass through the cover plate 1 and the lower plastic 7. The assembly part 2 is bent 90° by riveting or pressing, and the top of the groove 202 is used as the boundary when bending the assembly part 2. The design of the groove 202 can reduce the wall thickness of the assembly part 2, which can better bend the assembly part 2. After the assembly part 2 is bent, a retaining area 201 and a bending area 203 are formed. The cross-sectional views of the retaining area 201 and the bending area 203 are shown below. Arranged in an L-shape, the upper plastic 6 is injected into the space between the assembly part 2 and the pole post 4 via injection molding. The upper plastic 6 is made of PPS material. After the PPS is formed, the upper plastic 6 covers the enclosure area 201 and the bending area 203. The outer edge of the pole post 4 has a protruding area around it, and the outer end of the protruding area has a sloping outward protrusion 401. After bending, the bending area 203 forms a through hole in its center. The outer diameter of the protruding area is larger than the inner diameter of the through hole, so the bending area 203 can prevent the pole post 4 assembly from detaching. The outward protrusion 401 can increase the connection area with the upper plastic 6. Figure 8 The upper plastic 6 presses the pole post 4 and the sealing ring 5 together, and fills the space between the pole post 4 and the assembly part 2, which can play a good sealing role. The bending area 203 can prevent the upper plastic 6 from detaching from the pole post 4. The 90° bend formed by the bending area 203 can hook the inside of the upper plastic 6, indirectly fixing the pole post 4 assembly, thereby limiting the upward displacement of the entire pole post 4 assembly. The assembly part 2 forms a step part 3 by riveting. The step part 3 can resist the downward movement of the pole post 4 assembly and the lower plastic 7. Thus, the assembly part 2 can fix the pole post 4 assembly without welding, and ensure the sealing of the installation. It will not lead to a decrease in the top cover yield, and can also reduce the welding process. Faster riveting can be used for fixing, saving production costs.
[0022] Preferably, the outer wall of the assembly part 2 is provided with a plurality of grooves 202, the grooves 202 being blind holes, the upper plastic 6 penetrating into the grooves 202, and the depth of the grooves 202 being ≥0.1mm. The grooves 202 can play a positioning role. The upper plastic 6 cannot be twisted, ensuring connectivity. Furthermore, the blind hole-shaped grooves 202 located outside the assembly part 2 prevent fine metal shavings left over from manufacturing from easily entering the installation area of the pole post 4 assembly, thus ensuring normal electrical transmission of the pole post 4.
[0023] An explosion-proof hole and a liquid injection hole are provided on the first surface of the cover plate 1 between the mounting holes 101. The explosion-proof hole and the liquid injection hole pass through the cover plate 1. An explosion-proof valve is provided in the explosion-proof hole for explosion-proof pressure relief. Electrolyte can be injected into the shell through the liquid injection hole.
Claims
1. A lithium-ion battery top cover structure, comprising a cover plate and a lower plastic assembly fitted to the bottom of the top cover, characterized in that: The cover plate has a first surface and a second surface disposed opposite to the first surface, and the second surface faces downward. The first surface of the cover plate has a mounting hole that passes through the cover plate, and an electrode assembly is installed in the mounting hole. The inner wall of the mounting hole is formed into an assembly part by stamping, and the assembly part is formed into a stepped part by riveting. The cover plate, the assembly part and the stepped part are integrally formed. The outer wall of the assembly part is provided with a number of grooves, and the assembly part is limited to the pole assembly.
2. The lithium-ion battery top cover structure according to claim 1, characterized in that: A mounting hole is provided at the center of the stepped portion; The electrode assembly includes an electrode, an upper plastic part, and a sealing ring. The electrode passes through the mounting hole and the lower plastic part. The sealing ring is disposed between the electrode and the mounting hole at the mounting position. The upper plastic part is disposed between the assembly part and the electrode.
3. The lithium-ion battery top cover structure according to claim 2, characterized in that: The groove is a blind hole, and the assembly part is a retaining area and a bending area. The retaining area bends inward from the top of the groove to form the bending area.
4. The lithium-ion battery top cover structure according to claim 3, characterized in that: A gap is provided between the enclosure area and the pole, and the upper plastic is located within the gap, covering the enclosure area and the bending area.
5. A lithium-ion battery top cover structure according to claim 4, characterized in that: The plastic material penetrates into the groove, and the groove depth is ≥0.1mm.
6. The lithium-ion battery top cover structure according to claim 3, characterized in that: The outer edge of the pole post is provided with a circumferential protrusion, and the outer end of the protrusion is provided with a sloping protrusion.
7. A lithium-ion battery top cover structure according to claim 6, characterized in that: After the bending area is bent, a through hole is formed at the center, and the outer diameter of the protruding area is larger than the inner diameter of the through hole.
8. A lithium-ion battery top cover structure according to claim 6, characterized in that: The upper plastic is engaged with the protruding area of the electrode post.
9. A lithium-ion battery top cover structure according to claim 1, characterized in that: The cover plate has an explosion-proof hole and a liquid injection hole on its first surface between the mounting holes, and the explosion-proof hole and the liquid injection hole penetrate through the cover plate.