Anti-rotation structure of power battery

Abstract

The utility model discloses an anti-rotation structure of a power battery, which comprises a shell and a naked battery cell arranged in the shell, the naked battery cell is provided with a central hole, a collector plate is arranged on one side of the naked battery cell, a limiting rod is arranged in the central hole of the naked battery cell, and the limiting rod is fixedly connected with the shell; the current collecting disc comprises a disc-shaped body and a connecting piece extending outwards from the disc-shaped body, a middle through hole is formed in the middle of the disc-shaped body, an alignment hole corresponding to the middle through hole is formed in the connecting piece, the alignment hole is formed above the middle through hole, and the alignment hole and the middle through hole are coaxially formed; an annular insulating plastic layer is arranged on the inner wall of the middle through hole, a limiting part is arranged on the insulating plastic layer, a matching part matched with the limiting part in a concave-convex mode is arranged at the end, corresponding to the limiting part, of the limiting rod, the limiting rod is arranged in the insulating plastic layer in a penetrating mode, and the limiting part is in matched limiting connection with the matching part. The limiting rod fixedly connected with the shell is arranged, and the insulating plastic layer connected with the limiting rod in a limiting mode is arranged in the middle of the current collecting disc, so that rotation is effectively prevented.

Description

Technical Field

[0001] The utility model relates to the field of power batteries, in particular to an anti-rotation structure of a power battery. Background Art

[0002] At present, lithium-ion or sodium-ion cylindrical batteries have gradually become the mainstream products in the new energy industry due to their high energy density, good capacity consistency, and support for high-rate charge and discharge. More and more manufacturers choose the mechanical (rolling groove) sealing structure of cylindrical batteries to reduce costs and improve production capacity. Common problems are as follows: 1. In the existing cylindrical power battery structure, CID laser welding is performed at the middle positions of the top cover connecting piece and the explosion-proof valve. During long-term vibration during vehicle loading or drum testing, the bare battery cell drives the current collector plate connecting piece and the top cover connecting piece to rotate, and a large torque directly impacts the CID laser welding position, resulting in the occurrence of battery open circuit; 2. In the existing cylindrical power battery structure, during long-term vibration during vehicle loading or drum testing, the rotation of the bare battery cell impacts both the internal electrical connection position and the sealing position of the battery, which will further increase the probability of battery open circuit or the occurrence of battery leakage. Summary of the Invention

[0003] The purpose of the utility model is to provide an anti-rotation structure of a power battery to solve the problems of battery open circuit and leakage caused by the rotation of the bare battery cell driving the current collector plate in the existing power battery.

[0004] To achieve the above purpose, an anti-rotation structure of a power battery provided by the utility model includes a housing and a bare battery cell arranged in the housing. The bare battery cell has a central hole, and a current collector plate is arranged on one side of the bare battery cell. A limiting rod is arranged in the central hole of the bare battery cell, and the limiting rod is fixedly connected with the housing; the current collector plate includes a disc-shaped body and a connecting piece extending outward from the disc-shaped body. A central through hole is arranged in the middle of the disc-shaped body, and a positioning hole is arranged on the connecting piece corresponding to the central through hole. The positioning hole is arranged above the central through hole and is coaxially arranged with the central through hole; an annular insulating plastic layer is arranged on the inner wall of the central through hole, a limiting part is arranged on the insulating plastic layer, and a matching part which is in concave-convex fit with the limiting part is arranged at the end of the limiting rod corresponding to the limiting part. The limiting rod passes through the insulating plastic layer, and the limiting part is in limiting connection with the matching part.

[0005] Preferably, the limiting part is a convex part protruding towards the inner side of the insulating plastic layer. The limiting rod has a first end and a second end opposite to the first end. The matching part is arranged at the first end of the limiting rod, and the matching part is a groove recessed towards the inside of the limiting rod, and the groove extends to the end face of the first end of the limiting rod.

[0006] Preferably, there are at least two limiting parts, and the at least two limiting parts are evenly distributed on the inner wall of the insulating plastic layer. The corresponding mating parts are at least two, and the at least two mating parts are evenly distributed on the outer wall of the limiting rod.

[0007] Preferably, the alignment hole and the middle through hole have the same size.

[0008] Preferably, widening parts are arranged on both sides of the alignment hole, and the side surface of the widening part is in an outwardly convex arc shape.

[0009] Preferably, at least two welding grooves are arranged on the disc-shaped body, and the at least two welding grooves are symmetrically distributed.

[0010] Preferably, the housing is a hollow housing with openings at both ends. A welding bottom shell is integrally arranged at the second end of the limiting rod. The welding bottom shell closes the bottom end of the housing, and a cover body is arranged at the top end of the housing.

[0011] Preferably, a bearing step extending towards the inside of the housing is arranged at the bottom end of the housing, and the welding bottom shell is arranged on the bearing step and is welded to the bearing step.

[0012] Preferably, a recessed part recessed towards the inside of the housing is arranged on the welding bottom shell, and the recessed part is welded to the full pole ear on the bare battery cell close to the welding bottom shell.

[0013] Preferably, the first end of the limiting rod is arranged inside the cover body.

[0014] Compared with the prior art, the utility model effectively prevents rotation and ensures the electrical isolation between the limiting rod and the current collector plate by arranging a limiting rod fixedly connected to the housing and an insulating plastic layer arranged at the middle of the current collector plate and limitingly connected to the limiting rod, completely avoiding the large torque of the bare battery cell directly impacting the internal electrical connection position of the battery, finally avoiding the occurrence of an open circuit in the power battery, and also avoiding the leakage of the sealed structure power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the current collector plate at an angle in an embodiment of the utility model. At this time, the connecting piece of the current collector plate is not bent.

[0016] Figure 2 It is a structural diagram of the current collector plate at another angle in an embodiment of the utility model. At this time, the connecting piece of the current collector plate is not bent.

[0017] Figure 3 is Figure 1 the sectional structural diagram of.

[0018] Figure 4This is the structural diagram after bending the connecting piece of the current collector plate in the embodiment of the present utility model.

[0019] Figure 5 This is the structural diagram of the limiting rod in the embodiment of the present utility model.

[0020] Figure 6 This is the sectional structural diagram of the power battery in the embodiment of the present utility model. Detailed implementation manners

[0021] To describe in detail the technical content, structural features, and achieved effects of the present utility model, the following will be described in detail in conjunction with the implementation manners and with reference to the accompanying drawings.

[0022] As Figures 1 to 6 shown, the embodiment of the present utility model provides an anti-rotation structure for a power battery, including a housing 4 and a bare battery cell 5 disposed inside the housing 4. The bare battery cell 5 has a central hole, and a current collector plate 1 is disposed on one side of the bare battery cell 5. A limiting rod 2 is disposed in the central hole of the bare battery cell 5, and the limiting rod 2 is fixedly connected to the housing 4; the current collector plate 1 includes a disc-shaped body 11 and a connecting piece 12 extending outward from the disc-shaped body 11. A central through hole 111 is provided in the middle of the disc-shaped body 11. A positioning hole 121 is provided on the connecting piece 12 corresponding to the central through hole 111. The positioning hole 121 is disposed above the central through hole 111 and is coaxially arranged with the central through hole 111; an annular insulating plastic layer 13 is provided on the inner wall of the central through hole 111, and a limiting portion 131 is provided on the insulating plastic layer 13. A matching portion 211 that is in concave-convex fit with the limiting portion 131 is provided at the end of the limiting rod 2 corresponding to the limiting portion 131. The limiting rod 2 passes through the insulating plastic layer 13, and the limiting portion 131 and the matching portion 211 are in matching and limiting connection. Specifically, the power battery can be a cylindrical power battery, the current collector plate 1 is a positive current collector plate, and the insulating plastic layer 13 is formed in the middle of the disc-shaped body 11 by injection molding. As Figure 1 and Figure 3 shown, when assembled, the connecting piece 12 can be stacked on the disc-shaped body 11 by bending so that the central through hole 111 and the positioning hole 121 are correspondingly arranged, so that the limiting rod 2 passes through the central through hole 111 and the positioning hole 121. The limiting rod 2 and the disc-shaped body 11 are in limiting connection through the insulating plastic layer 13, thereby realizing the anti-rotation of the bare battery cell 5.

[0023] In the embodiment of the present utility model, by providing the limiting rod 2 fixedly connected to the housing 4 and arranging the insulating plastic layer 13 in the middle of the current collector plate 1 that is in limiting connection with the limiting rod 2, while effectively preventing rotation, it also ensures the electrical isolation between the limiting rod 2 and the current collector plate 1, completely avoiding the direct impact of a large torque of the bare battery cell 5 on the internal electrical connection position of the battery, finally avoiding the occurrence of an open circuit of the power battery, and at the same time avoiding the leakage of liquid from the sealed structure power battery.

[0024] In the embodiment of the present utility model, the limiting part 131 is a convex part protruding towards the inside of the insulating plastic layer 13. The limiting rod 2 has a first end 21 and a second end opposite to the first end 21. The matching part 211 is arranged at the first end 21 of the limiting rod 2. The matching part 211 is a groove recessed towards the inside of the limiting rod 2, and the groove extends to the end face of the first end 21 of the limiting rod 2 for easy assembly. Specifically, as Figure 5 shown, the matching part 211 is a groove recessed from the outer surface of the limiting rod 2 towards the inside. The anti-rotation of the bare battery cell 5 in the circumferential direction is realized by the concave-convex matching of the groove and the convex part, and the design is ingenious.

[0025] In the embodiment of the present utility model, there are at least two limiting parts 131, and the at least two limiting parts 131 are evenly distributed on the inner wall of the insulating plastic layer 13. The corresponding matching parts 211 are at least two, and the at least two matching parts 211 are evenly distributed on the outer wall of the limiting rod 2. Specifically, as Figure 1 shown, there are four limiting parts 131 and four matching parts 211. By evenly distributing the multiple limiting parts 131 and the multiple matching parts 211, the limiting effect can be better and more stable.

[0026] In the embodiment of the present utility model, the alignment hole 121 and the middle through hole 111 have the same size. Specifically, as Figure 6 shown, by setting the size of the alignment hole 121 to be the same as or close to the size of the middle through hole 111, the limiting rod 2 and the connecting piece 12 can be made not to contact, ensuring the electrical isolation between the limiting rod 2 and the connecting piece 12.

[0027] In the embodiment of the present utility model, widening parts 122 are arranged on both sides of the alignment hole 121, and the side surfaces of the widening parts 122 are outwardly convex arcs. Specifically, as Figures 1 to 2 shown, the arrangement of the widening parts 122 ensures the current-carrying area of the connecting piece 12 at the alignment hole 121, making the electrical performance of the power battery better.

[0028] In the embodiment of the present utility model, at least two welding grooves 112 are arranged on the disc-shaped body 11, and the at least two welding grooves 112 are symmetrically distributed. Specifically, as Figures 1 to 2 shown, there are three evenly distributed welding grooves 112. The disc-shaped body 11 and the positive full tab of the bare battery cell 5 are welded and connected through at least two welding grooves 112, and the connection is stable.

[0029] In the embodiment of the present utility model, as Figure 6As shown, the housing 4 is a hollow housing 4 with openings at both ends. A welding bottom case 3 is integrally provided at the second end of the limiting rod 2. The welding bottom case 3 closes the bottom end of the housing 4, and a cover body 6 is provided at the top end of the housing 4. Specifically, the limiting rod 2 and the welding bottom case 3 are integrally formed by stamping and stretching. In some other embodiments, the welding bottom case 3 can be welded to the end of the limiting rod 2. By integrally providing the welding bottom case 3 on the limiting rod 2, the connection between the limiting rod 2 and the housing 4 is more reliable and the installation is more convenient.

[0030] Furthermore, a bearing step 41 extending towards the inner side of the housing 4 is provided at the bottom end of the housing 4. The welding bottom case 3 is arranged on the bearing step 41 and is welded to the bearing step 41. Specifically, as Figure 6 shown, the welding bottom case 3 is arranged on the bearing step 41 and is laser welded to the bearing step 41, which is convenient for welding.

[0031] In the embodiment of the present utility model, a recessed portion 31 recessed towards the inside of the housing 4 is provided on the welding bottom case 3. The recessed portion 31 is welded to the full pole ear on the bare battery cell 5 close to the welding bottom case 3. Specifically, the thickness of the welding bottom case 3 is less than the thickness of the housing 4. By directly welding the welding bottom case 3 to the negative full pole ear at the bottom of the bare battery cell 5, it is possible to eliminate the need for an additional negative current collector plate, effectively saving process steps and costs. Moreover, the relatively thick bearing step 41 is used to support the power battery, and the strength of the power battery is good.

[0032] In the embodiment of the present utility model, the first end 21 of the limiting rod 2 is arranged inside the cover body 6. Specifically, as Figure 6 shown, a pole post 7 is provided on the cover body 6. The connecting piece 12 is welded to the pole post 7. By arranging the limiting rod 2 inside the cover body 6, the end of the first end 21 of the limiting rod 2 can be clamped with the cover body 6. By arranging the limiting rod 2 inside the cover body 6, the appearance of the power battery is more beautiful.

[0033] The assembly steps of the power battery in the embodiment of the present utility model are as follows: First, weld the welding groove 112 of the disc-shaped body 11 of the current collector plate 1 to one end of the full pole ear of the bare battery cell 5, laser weld the welding bottom case 3 to the bearing step 41 of the housing 4, then place the bare battery cell 5 in the housing 1 and circumferentially limit the connection between the current collector plate 1 and the limiting rod 2. Then, fit the connecting piece 12 to the bottom of the pole post 7 on the cover body 6 and fix it by laser welding. Then, bend the connecting piece 12 according to the preset position, fit the cover body 6 to the opening of the housing 4, and fix it by laser welding for sealing.

[0034] When the power battery of the embodiment of the utility model is subjected to vehicle loading vibration or drum testing, when the connecting piece 12 of the current collector plate 1 and the cover body 6 driven by the bare battery cell 5 are about to have a large rotational torque, stress cancellation and limitation are carried out under the action of the limiting part 131 of the current collector plate 1 and the limiting rod 2, completely avoiding the direct impact of the large torque of the bare battery cell 5 on the internal electrical connection position of the battery, finally avoiding the occurrence of open circuit of the power battery, and at the same time avoiding the leakage of liquid from the sealed cylindrical power battery.

[0035] The above-disclosed are only the preferred examples of the present utility model, and of course, the scope of rights of the present utility model cannot be limited thereby. Therefore, equivalent changes made according to the scope of the patent application of the present utility model still fall within the scope covered by the present utility model.

Claims

1. An anti-rotation structure of a power battery, characterized in that: It comprises a shell and a bare cell arranged in the shell, wherein the bare cell has a central hole and a current collecting plate is arranged on one side of the bare cell, a limiting rod is arranged in the central hole of the bare cell, and the limiting rod is fixedly connected to the shell; The collecting plate includes a disc-shaped body and a connecting piece extending outward from the disc-shaped body, a central through hole is provided in the middle of the disc-shaped body, an alignment hole is provided on the connecting piece corresponding to the central through hole, the alignment hole is provided above the central through hole and the alignment hole is coaxially arranged with the central through hole; an annular insulating plastic layer is provided on the inner wall of the central through hole, a limiting portion is provided on the insulating plastic layer, the end of the limiting rod is provided with a matching portion corresponding to the limiting portion and matching with the limiting portion in a concave and convex manner, the limiting rod is penetrated in the insulating plastic layer and the limiting portion is connected with the matching portion in a matching and limiting manner.

2. The anti-rotation structure of the power battery according to claim 1, characterized in that: The limiting portion is a protrusion protruding toward the inner side of the insulating plastic layer, the limiting rod has a first end and a second end opposite to the first end, the matching portion is arranged at the first end of the limiting rod, the matching portion is a groove recessed toward the inside of the limiting rod, and the groove extends to the first end surface of the limiting rod.

3. The anti-rotation structure of the power battery according to claim 1, characterized in that: There are at least two limiting parts, which are evenly distributed on the inner wall of the insulating plastic layer, and there are correspondingly at least two matching parts, which are evenly distributed on the outer wall of the limiting rod.

4. The anti-rotation structure of the power battery according to claim 1, characterized in that: The alignment hole has the same size as the middle through hole.

5. The anti-rotation structure of the power battery according to claim 1, characterized in that: Widened portions are arranged on both sides of the alignment hole, and the side surfaces of the widened portions are in an outwardly convex arc shape.

6. The anti-rotation structure of the power battery according to claim 1, characterized in that: At least two welding grooves are arranged on the disc-shaped body, and the at least two welding grooves are symmetrically distributed.

7. The anti-rotation structure of the power battery according to claim 2, characterized in that: The shell is a hollow shell with openings at both ends. The second end of the limiting rod is integrally provided with a welded bottom shell, the welded bottom shell seals the bottom end of the shell, and a cover body is provided at the top end of the shell.

8. The anti-rotation structure of the power battery according to claim 7, characterized in that: The bottom end of the shell is provided with a bearing step extending toward the inner side of the shell, and the welding bottom shell is arranged on the bearing step and is welded to the bearing step.

9. The anti-rotation structure of the power battery according to claim 8, characterized in that: The welding bottom shell is provided with a recessed portion recessed toward the inside of the shell, and the recessed portion is welded and connected to the full pole tab on the bare battery cell close to the welding bottom shell.

10. The anti-rotation structure of the power battery according to claim 7, characterized in that: The first end of the limiting rod is arranged on the inner side of the cover body.

Images