Battery riveting cover plate structure, battery cell and battery pack

Abstract

The utility model discloses a battery riveting cover plate structure, cell and battery pack, said cover plate structure includes substrate, positive pole subassembly, negative pole subassembly and lower plastic cement, said positive pole subassembly and negative pole subassembly both include pressure plate, upper plastic cement, seal ring and rivet, the composite ring comprises an inner ring and an outer ring, the inner ring and the cathode rivet are made of the same material, and the outer ring and the cathode pressing plate are made of the same material; according to the utility model, the composite ring is additionally arranged between the negative pressure plate and the negative pole, the inner side and the outer side of the composite ring are made of different metals and are connected with the negative pressure block and the negative pole in a riveting or welding manner, and the mechanical shock resistance of the cover plate pole is improved by utilizing the principle that the same metals are fused after being welded, so that the internal resistance fluctuation is reduced; the abnormal heat generation rate of the terminal is reduced; and the consistency of the battery cell is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery cover plate structures, and in particular relates to a battery riveted cover plate structure, a battery core and a battery pack. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of new energy, power batteries are increasingly widely used, and the requirements for battery cells are also constantly increasing. For square battery cells, riveted cover plates are extremely widely used. Ordinary riveted cover plates are riveted by the pole and the pressure plate, and then the riveted edges are welded to enhance the mechanical properties and conductivity. For example, a cover plate and a battery disclosed in Chinese utility model patent CN217788584U have the same structure as the positive electrode assembly and the negative electrode assembly. However, due to the specific requirements of power batteries, the negative electrode often uses copper pole ears, and the pack end is often connected with aluminum bars for optimal considerations. This requires that the negative electrode of the cover plate needs to meet the requirements of copper-copper welding at the transfer end and aluminum-aluminum welding at the external end.

[0004] In order to meet the above requirements, the negative electrode side is often riveted by copper-aluminum welding. After the aluminum molten pool solidifies, the copper negative electrode is squeezed to achieve a reinforcement effect, thereby enhancing the conductivity of the negative terminal. However, due to the loose fit of the copper-aluminum riveted structure, the copper-aluminum welding cannot achieve a true fusion effect. The battery cell will experience internal resistance fluctuations due to impact during use, thereby affecting the consistency of the battery cell's electrical performance. At the same time, when the internal resistance of the copper-aluminum weld increases due to impact, the heat generation will also increase, and the challenge of controlling the temperature of the aluminum bar at the pack end will also increase. Utility Model Content

[0005] The utility model aims to provide a battery riveted cover plate structure, a battery cell and a battery pack, which can improve the welding strength of the pole, thereby improving the impact resistance of the cover plate; can reduce the fluctuation of the cover plate resistance value, and improve the consistency of the battery cell.

[0006] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] In the first aspect, an embodiment of the utility model provides a battery riveted cover structure, including a substrate, a positive electrode assembly, a negative electrode assembly and a lower plastic, wherein the positive electrode assembly and the negative electrode assembly both include a pressure plate, an upper plastic, a sealing ring and a rivet, wherein a composite ring is arranged between the negative electrode pressure plate and the negative electrode rivet of the negative electrode assembly, wherein the composite ring includes an inner ring and an outer ring, wherein the inner ring is made of the same material as the negative electrode rivet, and the outer ring is made of the same material as the negative electrode pressure plate.

[0008] As a further technical solution, a mounting hole is provided in the middle of the pressure plate, and a first avoidance step surface and a second step surface are provided on the wall surface of the mounting hole.

[0009] As a further technical solution, the riveted portion on the upper part of the rivet of the positive electrode assembly is riveted to the second step surface on the pressing plate, and after riveting, the rivet of the positive electrode assembly and the pressing plate are welded to the first avoidance step surface.

[0010] As a further technical solution, the riveted portion on the upper part of the rivet of the negative electrode assembly is riveted to the inner ring riveting table on the composite ring. After riveting, the outer ring pressing surface on the composite ring is extruded and fixed to the second step surface on the negative electrode assembly pressure plate.

[0011] As a further technical solution, the rivet of the negative electrode assembly is reinforced with the upper contact surface of the inner ring of the composite ring by laser welding, and the pressure plate of the negative electrode assembly is reinforced with the upper contact surface of the outer ring of the composite ring by laser welding.

[0012] As a further technical solution, the pressing plate, the upper plastic, the sealing ring, the base plate and the lower plastic of the positive electrode assembly are all provided with mounting holes penetrating through the two side surfaces in the thickness direction thereof.

[0013] As a further technical solution, the rivets of the positive electrode assembly pass through the mounting holes on the sealing ring, the lower plastic, the base plate, the upper plastic and the pressure plate in sequence.

[0014] As a further technical solution, the pressure plate, upper plastic, sealing ring, composite ring, substrate and lower plastic of the negative electrode assembly are all provided with mounting holes that penetrate both sides in the thickness direction thereof, and the rivets of the negative electrode assembly pass through the mounting holes on the sealing ring, lower plastic, substrate, upper plastic, pressure plate and composite ring in sequence.

[0015] In a second aspect, an embodiment of the present utility model provides a battery cell, comprising the battery riveted cover plate structure of the first aspect.

[0016] In a third aspect, an embodiment of the present utility model provides a battery pack, comprising the battery cell described in the second aspect.

[0017] The beneficial effects of the above-mentioned embodiments of the utility model are as follows:

[0018] The battery riveted cover plate structure provided by the utility model increases a composite ring between the negative electrode pressure plate and the rivets on the negative electrode pole. Different metals are used inside and outside the composite ring, and the composite ring is connected to the negative electrode pressure block and the negative electrode pole by riveting or welding. The principle of the same metals fusing after welding is utilized to improve the mechanical impact resistance of the cover plate pole, thereby reducing internal resistance fluctuations, thereby reducing the incidence of abnormal heat generation of the terminal and improving the consistency of the battery cell.

[0019] The battery riveted cover plate structure provided by the utility model has an inner ring material of the composite ring that is the same as the negative electrode rivet material, and an outer ring material of the composite ring that is the same as the negative electrode pressure plate material. The same materials are easy to weld and fuse, thereby improving impact resistance and reducing the risk of internal resistance fluctuation.

[0020] The utility model provides a battery riveted cover plate structure, in which the negative electrode rivet and the composite ring are riveted to the inner ring riveted table surface, and after riveting, the outer ring crimping surface and the negative electrode pressure plate crimping second step surface are extruded and fixed, and after layer-by-layer transmission of the negative electrode assembly, the sealing ring compression and negative electrode sealing are finally formed; the negative electrode rivet and the upper contact surface of the inner ring are reinforced by laser welding; the negative electrode pressure plate and the upper contact surface of the outer ring are reinforced by laser welding, and after the riveting is completed, the negative electrode column is laser welded to improve the impact resistance and conductivity and reduce the internal resistance.

[0021] Compared with the transmission riveted cover plate, the battery riveted cover plate structure provided by the utility model can improve the welding strength of the pole, thereby improving the impact resistance of the cover plate, reducing the fluctuation of the cover plate resistance, and thereby improving the consistency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0023] Figure 1 This is a schematic diagram of the cover plate structure provided in an embodiment of the utility model;

[0024] Figure 2 An exploded view of the cover plate structure provided in an embodiment of the utility model;

[0025] Figure 3 A cross-sectional view of a cover plate structure provided in an embodiment of the utility model;

[0026] Figure 4 A schematic diagram of a pressing plate provided in an embodiment of the utility model;

[0027] Figure 5 It is a cross-sectional view of a composite ring provided in an embodiment of the utility model;

[0028] Figure 6 for Figure 3 An enlarged cross-sectional view of the negative electrode column in FIG.

[0029] The schematic diagram is for illustrative purposes only;

[0030] Among them, 100, substrate;

[0031] 110, positive electrode assembly; 111, positive electrode pressing plate; 112, positive electrode upper plastic; 113, positive electrode rivet; 1111, first avoidance step surface; 1112, second step surface;

[0032] 120, negative electrode assembly; 121, negative electrode pressure plate; 122, negative electrode plastic; 123, composite ring; 124, negative electrode rivet; 1211, welding first avoidance step surface; 1212, crimping second step surface; 1231, inner ring; 1232, outer ring; 1233, inner ring riveting table; 1234, outer ring crimping surface;

[0033] 130, plastic down;

[0034] 140. Sealing ring. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] Example 1

[0037] In a typical implementation of the present invention, Figure 1 As shown, a battery riveted cover structure is provided, including a substrate 100 , a positive electrode assembly 110 , a negative electrode assembly 120 and a lower plastic 130 .

[0038] like Figure 2 and Figure 3 As shown, the positive electrode assembly 110 includes a positive electrode pressing plate 111, a positive electrode upper plastic 112, a substrate 100, a lower plastic 130, a sealing ring 140 and a positive electrode rivet 113, and the negative electrode assembly 120 includes a negative electrode pressing plate 121, a negative electrode upper plastic 122, a substrate 100, a lower plastic 130, a sealing ring 140, a composite ring 123 and a negative electrode rivet 124. That is, the positive electrode assembly and the negative electrode assembly both include a pressing plate, an upper plastic, a sealing ring and a rivet.

[0039] Among them, a composite ring 123 is provided between the negative electrode pressing plate 121 and the negative electrode rivet 124 of the negative electrode assembly. Figure 5As shown, the composite ring 123 includes an inner ring 1231 and an outer ring 1232. The inner ring 1231 is made of the same material as the negative electrode rivet 124, and the outer ring 1232 is made of the same material as the negative electrode pressure plate 121. By adding a composite ring between the negative electrode pressure plate and the negative electrode column, different metals are used inside and outside the composite ring, and the composite ring is connected to the negative electrode pressure block and the negative electrode column by riveting or welding. The principle of the same metal fusing after welding is used to improve the ability of the cover plate column to resist mechanical impact, thereby reducing internal resistance fluctuations, thereby reducing the incidence of abnormal heat generation of the terminal and improving the consistency of the battery cell.

[0040] In this embodiment, a mounting hole is provided in the middle of the pressure plate, and a first avoidance step surface and a second step surface are provided on the wall surface of the mounting hole. Figure 4 As shown, a first avoidance step surface 1111 and a second step surface 1112 are provided on the positive electrode pressing plate 111 of the positive electrode assembly 110, wherein the riveting portion on the upper portion of the positive electrode rivet 113 of the positive electrode assembly 110 is riveted to the second step surface 1112 on the positive electrode pressing plate, and after riveting, the positive electrode rivet 113 of the positive electrode assembly and the positive electrode pressing plate 111 are welded to the first avoidance step surface 1111.

[0041] Furthermore, a first welded avoidance step surface 1211 and a crimped second step surface 1212 are provided on the positive electrode pressure plate 121 of the negative electrode assembly 100. The riveted portion of the upper portion of the negative electrode rivet 124 of the negative electrode assembly 120 is riveted to the inner ring riveted table surface 1233 on the composite ring 123. After riveting, the outer ring crimping surface 1234 on the composite ring 123 and the crimped second step surface 1212 on the negative electrode pressure plate 121 are extruded and fixed, and after being transferred layer by layer through the negative electrode assembly, the sealing ring is compressed and the negative electrode is sealed.

[0042] Furthermore, the negative electrode rivet 124 of the negative electrode assembly 120 and the upper contact surface of the inner ring of the composite ring 123 are reinforced by laser welding, and the negative electrode pressure plate 121 of the negative electrode assembly and the upper contact surface of the outer ring of the composite ring 123 are reinforced by laser welding.

[0043] In this embodiment, the positive electrode pressing plate 111, the positive electrode upper plastic 112, the sealing ring 140, the substrate 100 and the lower plastic 130 of the positive electrode assembly 110 are all provided with mounting holes that penetrate the two side surfaces in the thickness direction thereof. During installation, the positive electrode rivet 113 of the positive electrode assembly 110 passes through the mounting holes on the sealing ring 140, the lower plastic 130, the substrate 100, the positive electrode upper plastic 112 and the positive electrode pressing plate 111 in sequence.

[0044] In this embodiment, the negative electrode pressure plate 121, the negative electrode upper plastic 122, the sealing ring 140, the composite ring 123 of the negative electrode assembly 120, and the substrate 100 and the lower plastic 130 are all provided with mounting holes that penetrate the two sides in the thickness direction thereof. During installation, the negative electrode rivet 124 of the negative electrode assembly 120 passes through the mounting holes on the sealing ring 140, the lower plastic 130, the substrate 100, the negative electrode upper plastic 122, the negative electrode pressure plate 121 and the composite ring 123 in sequence. The structure after installation is as shown in FIG. Figure 6 shown.

[0045] In this embodiment, the rivet riveting structures of the positive electrode assembly 110 and the negative electrode assembly 120 are both I-shaped structures, wherein the negative electrode rivet 124 of the negative electrode assembly 120 has a smaller size than the positive electrode rivet 113 of the positive electrode assembly 110 to adapt to the installation of the composite ring.

[0046] In this embodiment, the inner ring 1231 and the outer ring 1232 of the composite ring 123 are crimped or welded to form an integrated composite structure. Since the outer wall surface of the inner ring 1231 and the inner wall surface of the outer ring 1232 are crimped or welded, the crimping or welding area is large, which is beneficial to improving the reinforcement effect.

[0047] The installation process of the battery riveted cover plate structure provided in this embodiment is as follows:

[0048] The positive electrode rivet 113 of the positive electrode assembly 110 is sequentially passed through the mounting holes on the sealing ring 140, the lower plastic 130, the substrate 100, the positive electrode upper plastic 112 and the positive electrode pressing plate 111; the negative electrode rivet 124 of the negative electrode assembly 120 is sequentially passed through the mounting holes on the sealing ring 140, the lower plastic 130, the substrate 100, the negative electrode upper plastic 122, the negative electrode pressing plate 121 and the composite ring 123;

[0049] The riveting portion of the upper portion of the positive electrode rivet 113 of the positive electrode assembly 110 is riveted to the second step surface 1112 of the positive electrode pressing plate. After riveting, the positive electrode rivet 113 of the positive electrode assembly and the positive electrode pressing plate 111 are welded to the first avoidance step surface 1111;

[0050] The riveting portion of the negative electrode rivet 124 of the negative electrode assembly 120 is riveted to the inner ring riveting table 1233 of the composite ring 123, and after riveting, the outer ring pressing surface 1234 of the composite ring 123 and the pressing second step surface 1212 of the negative electrode pressing plate 121 are pressed and fixed;

[0051] The negative electrode rivet 124 of the negative electrode assembly 120 and the upper contact surface of the inner ring of the composite ring 123 are reinforced by laser welding, and the negative electrode pressure plate 121 of the negative electrode assembly and the upper contact surface of the outer ring of the composite ring 123 are reinforced by laser welding.

[0052] The above-mentioned cover plate cooperates with the opening part of the battery cell shell. The battery cell includes a cover plate, a winding core, a mylar film, a shell, etc. The winding core can be welded and fixed to the cover plate through a transition piece to achieve the purpose of current transmission; the winding core can also be directly welded and fixed to the cover plate through the pole ear to achieve current transmission; the winding core is placed in the shell, and after the cover plate and the shell are matched, a seal is formed by welding to complete the installation of the battery.

[0053] The battery riveted cover structure provided in this embodiment adds a composite ring between the negative electrode pressure plate and the negative electrode pole. The inner ring material is the same as the negative electrode rivet material, and the outer ring material is the same as the negative electrode pressure plate 121 material. The same materials are easy to weld and fuse, thereby improving impact resistance and reducing the risk of internal resistance fluctuation. In addition, after the negative electrode pole is riveted, laser welding is used to improve impact resistance and conductivity and reduce internal resistance.

[0054] Example 2

[0055] In a typical implementation of the utility model, a battery cell is provided, comprising the battery riveted cover plate structure described in Example 1.

[0056] Example 3

[0057] In a typical embodiment of the present invention, a battery pack is provided, comprising the battery cell described in Example 2.

[0058] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A battery riveted cover structure, characterized in that: It includes a substrate, a positive electrode assembly, a negative electrode assembly and a lower plastic. The positive electrode assembly and the negative electrode assembly both include a pressure plate, an upper plastic, a sealing ring and a rivet. A composite ring is arranged between the negative electrode pressure plate and the negative electrode rivet of the negative electrode assembly. The composite ring includes an inner ring and an outer ring. The inner ring is made of the same material as the negative electrode rivet, and the outer ring is made of the same material as the negative electrode pressure plate.

2. The battery riveted cover structure according to claim 1, characterized in that: A mounting hole is arranged in the middle of the pressing plate, and a first avoidance step surface and a second step surface are arranged on the wall surface of the mounting hole.

3. The battery riveted cover structure according to claim 2, characterized in that: The riveting portion on the upper part of the rivet of the positive electrode assembly is riveted to the second step surface on the pressing plate, and after riveting, the rivet of the positive electrode assembly and the pressing plate are welded to the first avoidance step surface.

4. The battery riveted cover structure according to claim 2, characterized in that: The riveting part on the upper part of the rivet of the negative electrode assembly is riveted to the inner ring riveting table on the composite ring, and after riveting, the outer ring pressing surface on the composite ring is extruded and fixed to the second step surface on the negative electrode assembly pressing plate.

5. The battery riveted cover structure according to claim 4, characterized in that: The rivet of the negative electrode assembly is reinforced by laser welding with the upper contact surface of the inner ring of the composite ring, and the pressing plate of the negative electrode assembly is reinforced by laser welding with the upper contact surface of the outer ring of the composite ring.

6. The battery riveted cover structure according to claim 1, characterized in that: The pressing plate, the upper plastic, the sealing ring, the base plate and the lower plastic of the positive electrode assembly are all provided with mounting holes penetrating through the two side surfaces in the thickness direction thereof.

7. The battery riveted cover structure according to claim 6, characterized in that: The rivets of the positive electrode assembly pass through the sealing ring, the lower plastic, the base plate, the upper plastic and the mounting holes on the pressing plate in sequence.

8. The battery riveted cover structure according to claim 1, characterized in that: The pressing plate, upper plastic, sealing ring, composite ring, substrate and lower plastic of the negative electrode assembly are all provided with mounting holes penetrating both sides in the thickness direction thereof, and the rivets of the negative electrode assembly pass through the mounting holes on the sealing ring, lower plastic, substrate, upper plastic, pressing plate and composite ring in sequence.

9. A battery cell, characterized in that: The invention comprises the battery riveted cover plate structure as described in any one of claims 1 to 8.

10. A battery pack, characterized in that: Comprising the battery cell as claimed in claim 9.

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