A cover plate assembly and a square-shell battery cell

Abstract

This utility model provides a cover plate assembly and a square-shell battery cell, relating to the field of battery technology. The top cover has a first surface and a second surface disposed opposite to the first surface, with the second surface facing downwards. The first surface of the top cover has a mounting hole that passes through the top cover, and an electrode assembly is installed in the mounting hole. The first surface of the top cover and located outside the mounting hole have an assembly part, and the top of the assembly part has a pressing part. A chamfered area is provided between the assembly part and the pressing part. The wall thickness of the chamfered area decreases from top to bottom, and the wall thickness of the assembly part is less than the wall thickness of the pressing part. The pressing part is fixed to the top of the electrode assembly. The external fastener and the top cover are designed as an integral part, and the electrode assembly is fixed by bending, which can reduce the welding processing steps. At the same time, PPS only fills the space between the pressing part and the electrode, which does not consume too much material and can control production costs.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to a cover plate assembly and a square-shell battery cell. Background Technology

[0002] In recent years, with the vigorous development of new energy, various companies have gathered in the new energy field. The fierce competition has led to increasingly higher demands for cost, and the pursuit of the ultimate simplification of the top cover has become an urgent need for major battery manufacturers.

[0003] After electrolyte filling of a prismatic battery, the sealing between the terminals and the top cover is crucial to prevent leakage. Current sealing methods involve a sealing ring and upper plastic sealant filling the gap between the terminals and the top cover. To ensure a tight seal, the sealing ring and upper plastic sealant must be immovable and non-rotatable. Traditional top covers are mainly divided into injection-molded top covers, minimalist top covers, riveted top covers, and nano-top covers. To address the current industry demands for cost reduction and reliability, existing structures (such as...) Figure 9 As shown, injection-molded top covers are more expensive due to the large amount of PPS used, and because of the characteristics of PPS material, PPS is prone to deformation at high temperatures, leading to seal failure. In addition, the main difference between minimalist top covers and riveted top covers is that they have an additional laser welding step, welding a metal ring around the perimeter of the electrode hole to hold the electrode in place. This increased process is also a direct cause of increased manufacturing costs.

[0004] Therefore, to address the above issues, we propose a cover plate assembly and a square-shell battery cell, which have the advantages of low cost, no welding, and simple process. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the production cost of existing top covers is relatively high, which is not conducive to saving manufacturing costs. In view of the problems existing in the prior art, a cover plate assembly and a square-shell battery cell are provided.

[0006] The purpose and effects of this utility model are achieved by the following specific technical means:

[0007] A cover assembly includes a top cover and a lower plastic assembly fitted to the bottom of the top cover;

[0008] The top cover has a first surface and a second surface disposed opposite to the first surface, the second surface facing downward plastic, and the first surface of the top cover has a mounting hole that passes through the top cover, and an electrode assembly is installed in the mounting hole;

[0009] The first surface of the top cover is provided with an assembly part located outside the mounting hole, and the top of the assembly part is provided with a pressing part. A chamfered area is provided between the assembly part and the pressing part. The wall thickness of the chamfered area decreases from top to bottom, and the wall thickness of the assembly part is less than the wall thickness of the pressing part. The pressing part is fixed to the top of the pole assembly.

[0010] A further preferred embodiment: 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.

[0011] 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.

[0012] A further preferred embodiment: the first surface of the top cover, located between the mounting hole and the assembly part, is a stepped portion; there is a gap between the assembly part and the pole post; the upper plastic is located in the gap and covers the stepped portion.

[0013] A further preferred embodiment: the assembly part bends inward with the chamfered area as the boundary to form a pressing part, and the upper plastic part is connected to the pressing part to form an embedded part.

[0014] A further preferred embodiment: after the pressing part is bent, a through hole is formed in the center, and the outer diameter of the protruding area is larger than the inner diameter of the through hole.

[0015] A further preferred embodiment: the upper plastic is engaged with the protruding area of ​​the electrode post.

[0016] A further preferred embodiment: the assembly part and the pressing part form an external fixing structure. The external fixing structure is cylindrical or cylindrical with several gaps. When the assembly part is cylindrical with gaps, the number of gaps is 2-5.

[0017] A further preferred embodiment: the first surface of the top cover has an explosion-proof hole and a liquid injection hole between the mounting holes, and the explosion-proof hole and the liquid injection hole penetrate through the top cover.

[0018] The beneficial effects of this utility model are:

[0019] 1. The assembly part and the pressing part form the external fastener. When assembling the pole assembly, the sealing ring is first put into the pole, and then the pole with the sealing ring is assembled into the mounting hole. Then, the pressing part is bent at 90° by riveting or pressing. The assembly part and the pressing part are arranged in an L-shape. Finally, the upper plastic is injected into the space between the pressing part and the pole by one-piece injection molding. The upper plastic presses the pole and the sealing ring together. The bent part abuts against the top of the upper plastic, thereby restricting the upward displacement of the entire pole assembly. The external fastener and the top cover are designed as one piece. The pole assembly is fixed by bending, which can reduce the welding process. At the same time, PPS only fills the space between the pressing part and the pole, which will not consume too much material and can control production costs. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is an exploded view of the overall structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the top cover structure of this utility model;

[0023] Figure 3 This utility model Figure 2 A schematic diagram of a local structure in the image;

[0024] Figure 4 This utility model Figure 2 A schematic diagram of a local structure in the image;

[0025] Figure 5 This utility model Figure 2 The main view;

[0026] Figure 6 This utility model Figure 5 A magnified schematic diagram of the structure at point A in the diagram;

[0027] Figure 7 This is a front view of the top cover and pole assembly of this utility model in an assembled state.

[0028] Figure 8 This is a front view of the pole structure of this utility model;

[0029] Figure 9 This is a schematic diagram of a traditional PPS injection-molded pole structure.

[0030] Figures 1-8 Middle: Top cover 1, mounting hole 101, assembly part 2, chamfered area 201, pressing part 202, step part 3, pole post 4, outward protrusion 401, sealing ring 5, upper plastic 6, lower plastic 7. Detailed Implementation

[0031] 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.

[0032] Please see Figures 1-3A cover assembly includes a top cover 1 and a lower plastic 7 fitted to the bottom of the top cover 1. The top cover 1 has a first surface and a second surface disposed opposite to the first surface, the second surface facing the lower plastic 7. The first surface of the top cover 1 has a mounting hole 101 penetrating through the top cover 1, and an electrode assembly is installed in the mounting hole 101. There are two mounting holes 101, namely a positive electrode hole and a negative electrode hole, and the positive electrode assembly and the negative electrode assembly are respectively installed in the mounting holes 101. The electrode assembly includes an electrode 4. The upper plastic 6 and the sealing ring 5 are connected. The pole post 4 passes through the mounting hole 101 and the lower plastic 7. The sealing ring 5 is located between the pole post 4 and the mounting hole 101. The upper plastic 6 is located between the assembly part 2 and the pole post 4. 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 battery cell. The sealing ring 5 is compressed between the pole post 4 and the mounting hole 101. The sealing ring 5 can seal the connection gap between the pole post 4 and the mounting hole 101.

[0033] Please see Figures 1-4 and Figure 7 The top cover 1 has an assembly part 2 on its first surface, located outside the mounting hole 101, and the top of the assembly part 2 has a pressing part 202. The assembly part 2 and the pressing part 202 form an external fastener, such as... Figure 3 and Figure 4 The outer fastener is cylindrical or has several gaps. When the outer fastener is cylindrical with gaps, the gaps are preferably 2-5. When there are 2 gaps, the 2 gaps are preferably arranged horizontally symmetrically. The outer fastener does not obstruct the mounting hole 101 in its initial state. When assembling the pole post 4 assembly, first, the sealing ring 5 is fitted into the pole post 4. Then, the pole post 4 with the sealing ring 5 fitted is assembled into the mounting hole 101. Then, the pressing part 202 is bent 90° by riveting or pressing. The assembly part 2 and the pressing part 202 are arranged in an L-shape. Finally, the upper plastic 6 is injected into the space between the pressing part 202 and the pole post 4 by injection molding. The upper plastic 6 is PPS material. After the PPS is formed, as shown... Figure 7 The upper plastic 6 presses the pole post 4 and the sealing ring 5 together. The bent part abuts against the top of the upper plastic 6, thereby restricting the upward displacement of the entire pole post 4 assembly. The outer fastener and the top cover 1 are designed as a whole. The pole post 4 assembly is fixed by bending, which can reduce the welding process. At the same time, PPS only fills the space between the pressing part 202 and the pole post 4, which will not consume too much and can control the production cost.

[0034] Preferably, when the outer fastener is a cylindrical shape with several gaps, the PPS portion seeps into the gaps, and after the plastic 6 is formed, the portion located in the gaps can play a role in preventing rotation.

[0035] Furthermore, such as Figures 5-7After the pole post 4 is assembled into the mounting hole 101, when the pressing part 202 is bent at 90°, a chamfered area 201 is provided between the assembly part 2 and the pressing part 202. The pressing part 202 is bent with the chamfered area 201 as the boundary. Because the wall thickness of the chamfered area 201 decreases from top to bottom, the wall thickness at the thinning position is thinner, making it easier to fold and process. Taking the riveting process as an example, since the pressing part 202 is initially cylindrical, the riveting end of the processing equipment moves down while rotating to bend the pressing part 202. The processing can be completed in 3-4 seconds, which is fast. The processing efficiency of circles is higher than that of ellipses and polygons.

[0036] Preferred, such as Figures 5-7 After the pressing part 202 is bent, a through hole is formed in the center. PPS is injected between the assembly part 2 and the pole post 4 by injection molding. After cooling, PPS forms the upper plastic 6. The pressing part 202 is fixed to the top of the upper plastic 6. The first surface of the top cover 1 and the position between the outside of the mounting hole 101 and the inside of the assembly part 2 is the step part 3. The upper plastic 6 covers the step part 3. The step part 3 can restrict the downward movement of the upper plastic 6.

[0037] Preferred, such as Figure 7 and Figure 8 As shown, the connection position between the upper plastic 6 and the pressing part 202 forms an embedded part. This embedded part can improve the tightness, and the embedded part of the upper plastic 6 forms a two-sided contact with the right angle and the bending part, resulting in a larger contact area. This not only prevents the upper plastic 6 from moving upward, but also limits the horizontal shaking of the upper plastic 6, ensuring the sealing of the connection of the pole post 4. The outer edge of the pole post 4 is provided with a circumferential protrusion area, and the outer end of the protrusion area is provided with a sloped outward protrusion 401. The outward protrusion 401 is embedded in the upper plastic 6, which can increase the connection area between the pole post 4 and the upper plastic 6, thereby increasing the sealing of the connection and reducing the risk of leakage.

[0038] Preferred, such as Figure 1 The top cover 1 has an explosion-proof hole and an injection hole on its first surface between the mounting holes 101. The explosion-proof hole and the injection hole pass through the top cover 1. An explosion-proof valve is installed in the explosion-proof hole for explosion-proof pressure relief. Electrolyte can be injected into the shell through the injection hole.

Claims

1. A cover assembly, comprising a top cover and a lower plastic assembly fitted to the bottom of the top cover, characterized in that: The top cover has a first surface and a second surface disposed opposite to the first surface, the second surface facing downward plastic, and the first surface of the top cover has a mounting hole that passes through the top cover, and an electrode assembly is installed in the mounting hole; The first surface of the top cover is provided with an assembly part located outside the mounting hole, and the top of the assembly part is provided with a pressing part. A chamfered area is provided between the assembly part and the pressing part. The wall thickness of the chamfered area decreases from top to bottom, and the wall thickness of the assembly part is less than the wall thickness of the pressing part. The pressing part is fixed to the top of the pole assembly.

2. A cover plate assembly according to claim 1, wherein: The electrode assembly includes an electrode, an upper plastic part, and a sealing ring. The electrode passes through a mounting hole and a 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. A cover plate assembly according to claim 2, wherein: 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.

4. A cover plate assembly according to claim 3, wherein: The first surface of the top cover, located between the mounting hole and the assembly part, is a stepped portion. There is a gap between the assembly part and the pole post, and the upper plastic is located in the gap and covers the stepped portion.

5. A cover plate assembly according to claim 4, wherein: The assembly part bends inward from the chamfered area to form a pressing part, and the upper plastic part is connected to the pressing part to form an embedded part.

6. A cover plate assembly according to claim 5, wherein: After the pressure part is bent, a through hole is formed in the center, and the outer diameter of the protruding area is larger than the inner diameter of the through hole.

7. A cover plate assembly according to claim 6, wherein: The upper plastic is engaged with the protruding area of ​​the electrode post.

8. A cover plate assembly according to claim 1, wherein: The assembly part and the pressing part form an external fixing structure. The external fixing structure is cylindrical or has several gaps. When the assembly part is a cylindrical shape with gaps, the gaps are 2-5.

9. A cover plate assembly according to claim 1, wherein: The top cover 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 top cover.

10. A prismatic cell characterized by, It includes several cover plate assemblies as described in any one of claims 1-9.

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