Top cover assembly, battery monomer and battery assembly

Abstract

The utility model relates to the technical field of batteries, in particular to a top cover assembly, a battery monomer and a battery assembly. The top cover assembly comprises an insulating sheet, a top cover sheet, a negative electrode assembly and a positive electrode assembly, the insulating sheet comprises a first through hole and a second through hole, the top cover sheet comprises a negative electrode part corresponding to the first through hole, a positive electrode part corresponding to the second through hole and a remaining main body part, and the negative electrode assembly is installed on the negative electrode part; the positive electrode part comprises at least one convex part which protrudes towards the direction far away from the insulating sheet relative to the main body part, and the convex part forms the positive electrode assembly; the end surface of one end, far away from the insulating sheet, of the convex part is flush with the end surface of one end, far away from the insulating sheet, of the negative electrode assembly; and the outer convex part and the main body part are integrally formed. The outer convex part formed by stamping the top cover plate is used as the positive electrode, and a sealing ring, a positive electrode terminal, positive electrode upper plastic and other parts in a conventional structure are omitted, so that the cost is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a top cover subassembly, battery monomer and battery assembly. BACKGROUND

[0002] Current new energy industry is booming, electric vehicles generally enter the public view, power battery cost generally accounts for more than 40% of the whole vehicle, so the cost reduction of power battery is imminent. On the market, power battery structural parts are generally composed of top cover subassembly, aluminum shell and inner and outer insulation mode, wherein the top cover cost accounts for more than half of the structural parts.

[0003] In order to reduce the cost of top cover, the patent file with publication number CN218548593U discloses such a battery top cover and battery, the battery top cover includes a top cover plate and an insulating plate, the insulating plate is located below the top cover plate, the top cover plate is provided with a negative pole column assembly, the insulating plate is provided with a first through hole and a second through hole, the first through hole is located at one end of the insulating plate, and the first through hole is located at the corresponding position of the negative pole column assembly, the second through hole is located at the other end of the insulating plate, the position of the top cover plate corresponding to the second through hole is a positive pole area, the positive pole area is a solid structure, and the positive pole area and other areas of the top cover plate are an integral structure.

[0004] The prior art cancels the positive pole column, directly uses a part of the top cover plate as the positive pole area, so that the plane where the positive pole is located is lower than the plane where the negative pole is located. When a plurality of battery monomers need to be connected to form an entire battery pack, the position relationship of high and low is difficult to ensure the stability of the connection of the gasket between the positive pole and the negative pole of the two battery monomers, which affects the electrical connection effect. UTILITY MODEL CONTENTS

[0005] The utility model solves the above problems, and provides a top cover subassembly, battery monomer and battery assembly which are low in cost and facilitate stable connection of gaskets.

[0006] The technical scheme for solving the problem of the utility model is that firstly, a top cover subassembly is provided, which comprises an insulating sheet, a top cover sheet, a negative pole assembly and a positive pole assembly, the insulating sheet comprises a first through hole and a second through hole, the top cover sheet comprises a negative pole part corresponding to the first through hole, a positive pole part corresponding to the second through hole and a remaining main body part, the negative pole part is installed with the negative pole assembly, the positive pole part comprises at least one outward convex part which protrudes away from the insulating sheet relative to the main body part, the outward convex part forms the positive pole assembly, the end face of the outward convex part away from one end of the insulating sheet is flush with the end face of the negative pole assembly away from one end of the insulating sheet, and the outward convex part and the main body part are integrally formed.

[0007] As the preferred of the utility model, the positive pole part further includes at least one inner convex part protruding towards the direction of the insulating sheet relative to the main body part, the inner convex part passes through the second through hole; the inner convex part is integrally formed with the outer convex part.

[0008] As the preferred of the utility model, the outer convex part is centered on the inner convex part.

[0009] As the preferred of the utility model, the positive pole part includes the outer convex part, and the cross section of the outer convex part is annular.

[0010] As the preferred of the utility model, the positive pole part includes a plurality of outer convex parts, and the plurality of outer convex parts are annularly and uniformly arranged.

[0011] As the preferred of the utility model, the negative pole part includes a mounting hole continuous with the first through hole, the negative pole assembly includes a negative pole piece, the negative pole piece sequentially includes a lapping part lapped on the top cover sheet, a mounting part connected with the mounting hole hole wall and the first through hole hole wall, and a connecting end part along the direction from the top cover sheet to the insulating sheet, and the end face of the lapping part away from the one end of the insulating sheet is flush with the end face of the outer convex part away from the one end of the insulating sheet.

[0012] As the preferred of the utility model, the negative pole assembly further includes an insulating plastic piece arranged between the lapping part and the top cover sheet.

[0013] As the preferred of the utility model, the mounting hole sequentially includes an upper mounting hole and a lower mounting hole along the direction from the top cover sheet to the insulating sheet, the hole diameter of the upper mounting hole is greater than the hole diameter of the lower mounting hole, and the insulating plastic piece is arranged in the upper mounting hole.

[0014] Secondly, the utility model further provides a battery monomer, including any one top cover assembly. Wherein, the battery monomer can be lithium ion battery, sodium ion battery and the like.

[0015] Finally, the utility model further provides a battery assembly, including a plurality of battery monomers and a plurality of B sheets, the B sheet includes a positive pole connecting sheet for being connected with the outer convex part and a negative pole connecting sheet for being connected with the negative pole assembly.

[0016] The utility model has the advantages of:

[0017] 1. In this application, a top cover assembly, a battery monomer and a battery assembly are provided, in the top cover assembly and the battery monomer, the outer convex part formed by stamping the top cover sheet is used as the positive electrode, the sealing ring, the positive electrode terminal and the positive electrode upper plastic in the conventional structure are cancelled, and the cost is greatly reduced. At the same time, when the battery monomer with the top cover assembly is used in the battery assembly, the end face of the outer convex part is flush with the end face of the negative electrode assembly, which facilitates the stable connection of the gasket between the outer convex part and the negative electrode assembly, and ensures the electrical connection effect in the battery pack. In addition, compared with the flat plate structure in the prior art, the convex structure optimizes the stress distribution, can effectively disperse the external force received by the top cover sheet, prevent local damage, and improve the structural stability of the top cover sheet.

[0018] 2. In some embodiments, the top cover sheet is further stamped to form an inner convex part for direct electrical connection with the battery cell, compared with the prior art, without adding a metal connecting piece between the top cover sheet and the battery cell, reducing the number of connection points and improving the reliability of the connection.

[0019] 3. In some embodiments, the structure of the negative electrode assembly is adjusted, and the negative electrode part similar to the outer convex part and the inner convex part of the positive electrode part balances the mechanical structure at both ends of the top cover sheet and the insulating sheet, improving the structural stability of the top cover sheet and the insulating sheet. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of a top cover assembly;

[0021] Figure 2 is a sectional view of a top cover assembly;

[0022] Figure 3 is a structural schematic diagram of a positive electrode part in a top cover assembly;

[0023] Figure 4 is a structural schematic diagram of a negative electrode part in a top cover assembly;

[0024] In the figure: insulating sheet 1, first through hole 11, second through hole 12, top cover sheet 2, negative electrode part 21, positive electrode part 22, outer convex part 221, inner convex part 222, main body part 23, negative electrode part 31, lap joint part 311, mounting part 312, connecting end part 313, insulating plastic part 32. DETAILED DESCRIPTION

[0025] The following is a specific embodiment of the present application, and the technical scheme of the present application is further described in combination with the drawings, but the present application is not limited to these embodiments.

[0026] A top cover assembly, such as Figure 1 and Figure 2As shown, the assembly includes an insulating sheet 1 and a top cover sheet 2 stacked together. The top cover sheet 2 is typically made of a metal material, such as an aluminum plate, and has a certain degree of conductivity. The insulating sheet 1 is typically made of an insulating material, such as plastic, and has an insulating effect. When this top cover assembly is used in a battery, the insulating sheet 1 is located inside the battery, and the top cover sheet 2 is located outside the battery. The connection method between the insulating sheet 1 and the top cover sheet 2 is not limited, such as... Figure 2 As shown, slots can be provided at both ends of the insulating sheet 1 and blocks can be provided at both ends of the top cover sheet 2, so that the positioning and connection between the insulating sheet 1 and the top cover sheet 2 can be achieved by the engagement of the slots and blocks.

[0027] The top cover assembly also needs to house the negative and positive terminal components to supply power from the internal battery cells. Generally, it's necessary to ensure that one end of each component is located outside the battery, and the other end is inside, electrically connected to the internal battery cells. Therefore, if... Figure 2 As shown, the insulating sheet 1 inevitably has a first through hole 11 and a second through hole 12. The lower end of the negative electrode assembly and the lower end of the positive electrode assembly can pass through the first through hole 11 and the second through hole 12 respectively and then contact the battery cell inside the battery.

[0028] Corresponding to the insulating sheet 1, the top cover sheet 2 includes a negative electrode portion 21 corresponding to the first through hole 11, a positive electrode portion 22 corresponding to the second through hole 12, and the remaining main body portion 23. The negative electrode portion 21 is fitted with a negative electrode assembly, while generally, the positive electrode portion 22 is fitted with a positive electrode assembly. However, in this application, in order to reduce the cost of the top cover assembly, at least the shape and structure of the positive electrode portion 22 and the positive electrode assembly have been adjusted. Specifically: Figure 2 and Figure 3 As shown, the positive electrode portion 22 includes at least one outwardly protruding portion 221 that protrudes away from the insulating sheet 1 relative to the main body portion 23. The positive electrode assembly is formed directly from the outwardly protruding portion 221, reducing the need for traditional positive electrode assemblies and related components, thereby lowering costs. The outwardly protruding portion 221 is typically formed by stamping, so that it is integrally formed with the main body portion 23. Since the top cover sheet 2 is usually made of aluminum, which has good stamping properties, the forming method of the outwardly protruding portion 221 is simple and effective. Furthermore, the integral forming method allows the battery cell, positive electrode assembly, top cover sheet 2, and battery casing to be electrically connected sequentially, resulting in a smaller potential difference between the battery cell and the casing, reducing or even eliminating the problem of corrosion of the battery casing.

[0029] The size of the protruding portion 221 should be limited, and the end face of the protruding portion 221 away from the insulating sheet 1 should be flush with the end face of the negative electrode assembly away from the insulating sheet 1, i.e., as shown below. Figure 2 As shown, the upper surface of the protruding part 221 and the upper surface of the negative electrode assembly are on the same horizontal plane to facilitate the subsequent connection of the electrode plate.

[0030] The shape of the outer convex portion 221 is not limited, and when punching, the corners of the outer convex portion 221 are preferably rounded to reduce stress concentration. In some embodiments, the entire positive electrode portion 22 can be punched outwardly so that the positive electrode portion 22 includes an outer convex portion 221, and the cross section of the outer convex portion 221 can be circular, square, etc., and is generally circular to match the shape of the positive electrode column in the prior art; however, such an outer convex portion 221 increases the distance between the lower surface of the positive electrode portion 22 near the insulating sheet 1 and the internal battery cell, which is not conducive to electrical connection between the two. Figure 2

[0031] Therefore, in other embodiments, only the outer circumferential portion of the positive electrode portion 22 can be punched outwardly, for example, the positive electrode portion 22 can include a plurality of point-shaped outer convex portions 221, and the plurality of outer convex portions 221 are uniformly arranged in a ring shape and collectively form a positive electrode column; wherein the ring shape can be a circular ring, a square ring, etc., and is generally a circular ring considering the shape and structure of the conventional positive electrode column. For example, in the present embodiment, the positive electrode portion 22 includes an outer convex portion 221, and the outer convex portion 221 is punched in the direction shown in Figure 2 , and the cross section obtained by cutting the outer convex portion 221 is a ring shape, which can be a circular ring, a square ring, etc.; as shown in Figure 1 , the present embodiment is a circular ring, and such a ring-shaped outer convex portion 221 can be punched using a ring-shaped die.

[0032] In the embodiment of the ring-shaped outer ring portion 221, the lower surface of the portion between the ring-shaped outer ring portions 221 is used to connect with the internal battery cell, and this portion can not be punched and remain flush with the main body portion 23, in which case a metal connecting piece is still needed between the portion and the cell to achieve connection. Therefore, on the basis of the embodiment in which only the outer circumferential portion of the positive electrode portion 22 is punched outwardly, further, as shown in Figure 2 and Figure 3 , the positive electrode portion 22 further includes at least one inner convex portion 222 that protrudes in the direction of the insulating sheet 1, i.e., downwardly, relative to the main body portion 23, and the inner convex portion 222 is integrally formed with the outer convex portion 221. The size of the inwardly punched inner convex portion 222 is determined according to the distance between the inner convex portion 222 and the cell, and a suitable die is selected to enable direct contact and electrical connection with the cell. Compared with the method of connecting by using a metal connecting piece, which has two connection points between the positive electrode portion 22 and the metal connecting piece and between the metal connecting piece and the cell, the inner convex portion 222 has only one connection point with the cell, which reduces the probability of disconnection and improves the reliability of the connection.

[0033] ​The shape of the inner protrusion 222 is not limited, and preferably, the corners of the inner protrusion 222 are rounded to reduce stress concentration during stamping. The cross section of the inner protrusion 222 can be circular, annular, square, square annular, etc., and to improve the convenience of stamping and further reduce stress concentration, the cross section of the inner protrusion 222 can be circular. Further, the outer protrusion 221 is preferably controlled to be centered on the inner protrusion 222 to improve the stability of the overall structure of the positive electrode part 22.

[0034] In the embodiment in which the inner protrusion 222 is added, the inner protrusion 222 needs to be connected to the battery internal cell and thus needs to pass through the second through hole 12 of the insulating sheet 1. To further improve the structural strength of the top cover assembly, in some embodiments, as shown in Figure 3 the side wall of the inner protrusion 222 abuts the hole wall of the second through hole 12 to achieve the effect of mutual support.

[0035] The structure of the negative electrode part 21 and the way of installing the negative electrode assembly can be consistent with the prior art, and thus will not be described here. In some embodiments, further arrangements can be made based on the protruding structure of the positive electrode part 22 to improve the structural balance of the top cover assembly: as shown in Figure 2 the negative electrode part 21 includes a mounting hole continuous with the first through hole 11, and the negative electrode assembly includes a negative electrode piece 31 arranged in the mounting hole and the first through hole 11. As shown in Figure 4 the negative electrode piece 31 includes, in the direction from the top cover sheet 2 to the insulating sheet 1, i.e., from top to bottom, a lapping part 311 lapped on the top cover sheet 2, a mounting part 312 connected to the hole wall of the mounting hole and the first through hole 11, and a connecting end part 313, so as to design the negative electrode piece 31 as a "concave" shape, form a structure similar to the positive electrode part 22 with the outer protrusion 221 and the inner protrusion 222, and play a role in structural balance; and the design of the lapping part 311 can help the negative electrode piece 31 to be better fixed in the mounting hole and the first through hole 11 and not easy to fall off. Among them, the end face of the lapping part 311 away from the insulating sheet 1, i.e., the upper end face, is flush with the upper end face of the outer protrusion 221 to ensure the stability of the subsequent tab connection; further, the lower end face of the connecting end part 313 can be adjusted to be flush with the lower end face of the inner protrusion 222 to be connected to the battery internal cell.

[0036] The negative electrode piece 21 can be integrally formed, or as shown in Figure 4 the negative electrode piece 21 is composed of two parts, the outer part is used to connect with the top cover sheet 2 and the insulating sheet 1, and the inner part is used to connect with the subsequent tab.

[0037] In order to ensure the negative electrode insulation, as shown in Figure 2 and Figure 4As shown, the negative electrode assembly further comprises an insulating plastic piece 32 arranged between the lap joint 311 and the top cover sheet 2. The insulating plastic piece 32 can be a rubber ring, which has an L-shaped vertical cross section and comprises a horizontal first insulating portion arranged between the lap joint 311 and the top cover sheet 2 and a vertical second insulating portion abutting against the side surface of the lap joint 311, so as to improve the insulation effect. Further, in some embodiments, a mounting hole is arranged as a stepped hole, which comprises an upper mounting hole and a lower mounting hole in sequence from the top cover sheet 2 to the insulating sheet 1. The upper mounting hole has a larger hole diameter than the lower mounting hole. The lower end of the upper mounting hole and the upper end of the lower mounting hole are connected by a connecting surface. The insulating plastic piece 32 can be arranged in the upper mounting hole. The second insulating portion of the insulating plastic piece 32 is clamped between the hole wall of the upper mounting hole and the side surface of the lap joint 311. The first insulating portion is clamped between the connecting surface and the lap joint 311, so as to limit the position of the insulating plastic piece 32 and ensure the insulation effect.

[0038] Further, in some embodiments, a sealing piece is further arranged between the negative electrode piece 31 and the mounting hole. Similar to the insulating plastic piece 32, the sealing piece can be a sealing ring, which has an L-shaped vertical cross section and comprises a first sealing portion and a second sealing portion. The first sealing portion is clamped between the lap joint 311 and the connecting surface in an interference manner. The second sealing portion is clamped between the mounting portion 312 and the hole wall of the lower mounting hole in an interference manner, so as to improve the sealing performance and the fixing effect of the negative electrode piece 31 in the mounting hole.

[0039] In addition, similar to the existing top cover assembly, the top cover assembly of the present application further comprises an explosion-proof assembly, a liquid injection hole and the like. For example, in some embodiments, the top cover sheet 2 is provided with an explosion-proof valve hole in which an explosion-proof valve is arranged. The top cover sheet 2 is further provided with a protective sheet covering the explosion-proof valve hole. In some embodiments, the top cover sheet 2 is provided with a liquid injection hole. The insulating sheet 1 is provided with a third through hole continuous with the liquid injection hole.

[0040] A battery monomer comprising the above-described top cover assembly. The battery monomer can be any one of a lithium ion battery and a sodium ion battery, which has the advantage of low cost.

[0041] A battery assembly comprising a plurality of battery monomers provided with the above-described top cover assembly and a plurality of separators. The separator comprises a positive electrode connecting sheet for connecting with the end surface of the outer protrusion and a negative electrode connecting sheet for connecting with the end surface of the negative electrode assembly, which has the advantages of low cost and good electrical connection stability between the battery monomers.

[0042] The specific embodiments described herein merely exemplify the spirit of the present application. Those skilled in the art to which the present application belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A top cover assembly, comprising an insulating sheet (1), a top cover sheet (2), a negative electrode assembly and a positive electrode assembly, the insulating sheet (1) comprising a first through hole (11) and a second through hole (12), the top cover sheet (2) comprising a negative electrode portion (21) corresponding to the first through hole (11), a positive electrode portion (22) corresponding to the second through hole (12), and a remaining main body portion (23), the negative electrode portion (21) mounting the negative electrode assembly; the positive electrode portion (22) comprising at least one outer protruding portion (221) protruding away from the main body portion (23) towards the insulating sheet (1), the outer protruding portion (221) forming the positive electrode assembly; an end face of the outer protruding portion (221) away from the insulating sheet (1) being flush with an end face of the negative electrode assembly away from the insulating sheet (1); the outer protruding portion (221) being integrally formed with the main body portion (23). characterized in that The positive electrode portion (22) further comprises at least one inner protruding portion (222) protruding towards the insulating sheet (1) relative to the main body portion (23), the inner protruding portion (222) passing through the second through hole (12); the inner protruding portion (222) being integrally formed with the outer protruding portion (221).

2. A roof assembly according to claim 1, wherein: The outer protruding portion (221) is centered on the inner protruding portion (222).

3. A roof assembly according to claim 2, wherein: The positive electrode portion (22) comprises one outer protruding portion (221), a cross section of the outer protruding portion (221) being annular.

4. A roof assembly according to claim 1 or 2 or 3, wherein: The positive electrode portion (22) comprises a plurality of outer protruding portions (221), the plurality of outer protruding portions (221) being annularly and uniformly arranged.

5. A roof assembly according to claim 1 or 2 or 3, wherein: The negative electrode portion (21) comprises a mounting hole continuous with the first through hole (11), the negative electrode assembly comprising a negative electrode piece (31), the negative electrode piece (31) comprising, in order from the top cover sheet (2) to the insulating sheet (1), an overlapping portion (311) overlapping the top cover sheet (2), a mounting portion (312) connected with a hole wall of the mounting hole and a hole wall of the first through hole (11), and a connecting end portion (313); an end face of the overlapping portion (311) away from the insulating sheet (1) being flush with an end face of the outer protruding portion (221) away from the insulating sheet (1).

6. A roof assembly according to claim 2, wherein: The negative electrode assembly further comprises an insulating plastic piece (32) arranged between the overlapping portion (311) and the top cover sheet (2).

7. A roof assembly according to claim 6, wherein: The mounting hole comprises, in order from the top cover sheet (2) to the insulating sheet (1), an upper mounting hole and a lower mounting hole, a hole diameter of the upper mounting hole being larger than a hole diameter of the lower mounting hole, the insulating plastic piece (32) being arranged in the upper mounting hole.

8. A roof assembly according to claim 7, wherein: A battery comprising the top cover assembly according to any one of claims 1-8.

9. A battery cell characterized by: A battery comprising a plurality of battery cells according to claim 9, and a plurality of bus bars, the bus bars comprising positive electrode connecting pieces for connecting with the outer protruding portions (221), and negative electrode connecting pieces for connecting with the negative electrode assemblies.

10. A battery assembly characterized by: ​

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