Power battery

Abstract

The utility model discloses a power battery which comprises a shell, a top cover and a naked battery cell, the top cover seals the upper part of the shell, the upper end of the naked battery cell is provided with a current collecting disc, the current collecting disc comprises a disc-shaped main body and a connecting sheet which extends from one side of the disc-shaped main body and is bent, and the connecting sheet is arranged above the disc-shaped main body in an overlapping manner; an annular sealing ring is arranged between the shell and the top cover, the annular sealing ring is located above the disc-shaped main body, the lower portion of the annular sealing ring extends downwards to form at least two limiting protrusions corresponding to the connecting piece, and the at least two limiting protrusions are arranged on the two sides of the connecting piece in the width direction respectively and used for limiting rotation of the connecting piece. According to the utility model, the at least two limiting bulges are respectively arranged on the two sides of the width direction of the connecting piece to limit the connecting piece, so that the naked battery core is prevented from rotating, and the naked battery core is effectively prevented from rotating to impact welding spots of an explosion-proof welding piece at the upper part of the power battery and a top cover welding piece and welding spots of a bottom shell of the power battery and a negative current collecting disc; and battery open circuit and liquid leakage are prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a power battery. Background Art

[0002] With the increasingly serious crisis of non-renewable energy and the strong guidance of national policies, electric vehicles have become the main trend of the future development of the automobile industry. As an important component of electric vehicles, power batteries have the highest installed capacity in the field of electric vehicles due to their advantages such as small size, high energy density and green environmental protection. At present, lithium-ion / 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 charging and discharging. More and more manufacturers choose the rolling groove sealing structure of cylindrical battery machinery to achieve cost reduction and increase production capacity. Common problems: 1. The rolling groove sealing structure of the cylindrical power battery machinery, the top cover connecting piece and the middle position of the explosion-proof valve are CID laser welded. When the vehicle is loaded with long-term vibration or roller test, the winding core drives the collector plate connecting piece and the top cover connecting piece to rotate. The large torque directly impacts the CID laser welding position, resulting in the occurrence of battery open circuit; 2. The cylindrical power battery with mechanical rolling groove sealing structure, when the vehicle is loaded with long-term vibration or roller test, the rotation of the winding core will impact the shell bottom resistance welding position and the rolling groove sealing structure, which will further increase the probability of battery open circuit or battery leakage. Summary of the invention

[0003] The utility model aims to provide a power battery to solve the problem that the bare battery core in the existing power battery rotates, causing the battery to open circuit and leak.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a power battery, including a shell, a top cover and a bare battery cell arranged inside the shell, the top cover closes the upper part of the shell, and a current collecting plate is arranged at the upper end of the bare battery cell, the current collecting plate includes a disc-shaped body and a connecting piece extending and bent from one side of the disc-shaped body, the connecting piece is stacked above the disc-shaped body, an annular sealing ring is arranged between the shell and the top cover, the annular sealing ring is located above the disc-shaped body and the lower part of the annular sealing ring corresponds to the connecting piece and extends downward with at least two limiting protrusions, and the at least two limiting protrusions are respectively arranged on both sides of the connecting piece in the width direction to limit the rotation of the connecting piece.

[0005] Preferably, two adjacent limiting protrusions located on both sides of the width direction of the connecting piece are symmetrically arranged on both sides of the width direction of the connecting piece.

[0006] Preferably, the limiting protrusion is close to the side wall of the connecting piece and abuts against the side of the connecting piece.

[0007] Preferably, the connecting piece includes a first end connected to the disc-shaped body and a second end opposite to the first end, and the limiting protrusions include four, namely a first protrusion, a second protrusion, a third protrusion and a fourth protrusion, the first protrusion and the second protrusion are symmetrically arranged on both sides of the first end, and the third protrusion and the fourth protrusion are symmetrically arranged on both sides of the second end.

[0008] Preferably, the cross section of the limiting protrusion is an inverted trapezoidal structure or the cross section of the limiting protrusion is a U-shaped structure with the opening facing outward.

[0009] Preferably, the annular sealing ring includes a sealing body and the limiting protrusion extending downward from the sealing body, the limiting protrusion has a free end surface away from the sealing body, and the free end surface is connected to the side surface of the limiting protrusion through a guide chamfer.

[0010] Preferably, the difference between the distance between two adjacent limiting protrusions located on both sides of the connecting piece in the width direction and the width of the connecting piece is greater than or equal to 0.05 mm and less than or equal to 0.2 mm.

[0011] Preferably, the annular sealing ring includes a sealing body and a limiting protrusion extending downward from the sealing body, the limiting protrusion has a free end surface away from the sealing body, and the distance between the free end surface and the sealing body is greater than or equal to 0.05 mm and less than or equal to 1.5 mm.

[0012] Preferably, the annular sealing ring is integrally injection molded.

[0013] Preferably, the top cover also includes a top cover welding plate and an explosion-proof welding plate, the top cover welding plate is arranged above the connecting plate and is welded to the connecting plate, and the explosion-proof welding plate is arranged above the top cover welding plate and is welded to the top cover welding plate.

[0014] Compared with the prior art, the utility model provides at least two limiting protrusions at the lower part of the annular sealing ring and at least two limiting protrusions are respectively provided on both sides of the width direction of the connecting piece so that the connecting piece is embedded between two adjacent limiting protrusions to limit the connecting piece in the circumferential direction, thereby preventing the connecting piece from rotating, and further preventing the bare battery cell from rotating, thereby effectively preventing the bare battery cell from rotating and impacting the welding points of the explosion-proof welding piece on the upper part of the power battery and the top cover welding piece and the welding points of the bottom shell of the power battery and the negative electrode collector, thereby preventing the battery from opening and leaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of a power battery according to an embodiment of the utility model.

[0016] Figure 2It is a three-dimensional structural diagram of the annular sealing ring of the power battery according to an embodiment of the utility model.

[0017] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0018] Figure 4 It is a side view of the annular sealing ring of the power battery according to an embodiment of the utility model.

[0019] Figure 5 It is a top view of the annular sealing ring of the power battery according to an embodiment of the utility model.

[0020] Figure 6 This is a structural diagram of the positive electrode current collecting disk of a power battery according to an embodiment of the utility model.

[0021] Figure 7 This is a structural diagram of a bare power battery cell according to an embodiment of the utility model, in which the positive electrode has a positive electrode collector and an insulating gasket, and the negative electrode has a negative electrode collector.

[0022] Figure 8 This is a structural diagram of the connection between the annular sealing ring of the power battery and the collecting plate in an embodiment of the utility model.

[0023] Fig. 9 This is a structural diagram of another limiting protrusion on the annular sealing ring of the power battery in an embodiment of the utility model. DETAILED DESCRIPTION

[0024] In order to explain the technical content, structural features and effects achieved by the present invention in detail, the following is a detailed description in conjunction with the implementation modes and the accompanying drawings.

[0025] like Figures 1 to 9 As shown, the utility model provides a power battery, including a shell 1, a top cover 2 and a bare battery cell 3 arranged inside the shell 1, the top cover 2 closes the upper part of the shell 1, and a current collecting plate 4 is arranged at the upper end of the bare battery cell 3, the current collecting plate 4 includes a disc-shaped body 41 and a connecting piece 42 extending and bent from one side of the disc-shaped body 41, the connecting piece 42 is stacked above the disc-shaped body 41, and an annular sealing ring 6 is arranged between the shell 1 and the top cover 2, the annular sealing ring 6 is located above the disc-shaped body 41 and the lower part of the annular sealing ring 6 extends downwardly corresponding to the connecting piece 42 with at least two limiting protrusions 62, and the at least two limiting protrusions 62 are respectively arranged on both sides of the connecting piece 42 in the width direction to limit the rotation of the connecting piece 42.

[0026] Specifically, Figures 1 to 9As shown, the power battery 10 is a cylindrical power battery, the shell 1 is a columnar structure with an upper opening, the top cover 2 closes the upper opening and is sealed by mechanical rolling grooves, the annular sealing ring 6 is arranged between the top cover 2 and the shell 1 to be used for insulating and sealing the top cover 2 and the shell 1, and the current collecting disk 4 arranged on the upper part of the bare battery cell 3 is a positive current collecting disk, and the positive current collecting disk includes a disk-shaped body 41 and a connecting piece 42 extending and bent from one side of the disk-shaped body 41, the connecting piece 42 and the disk-shaped body 41 form a Z-shaped structure, the extending direction of the connecting piece 42 is the direction of the length of the connecting piece 42, and the direction corresponding to the length direction is the width direction, as shown in FIG. Figures 7 and 8 As shown, an insulating gasket 23 is also stacked on the disc-shaped main body 41, and an avoidance hole 231 is provided on the insulating gasket 23 for avoiding the connecting piece 42. The connecting piece 42 passes through the avoidance hole 231 and is stacked on the top of the insulating gasket 23. The top cover 2 also includes a top cover welding piece 21 and an explosion-proof welding piece 22. The top cover welding piece 21 is arranged above the connecting piece 42 and is welded to the connecting piece 42. The explosion-proof welding piece 22 is arranged above the top cover welding piece 21 and is welded to the top cover welding piece 21. The middle part of the explosion-proof welding piece 22 is connected to the middle part of the top cover welding piece 21 by laser welding. A negative electrode collector plate 5 is provided at the lower end of the bare battery cell 3, and the middle part of the negative electrode collector plate 5 is welded to the bottom shell 11 at the bottom of the shell 1.

[0027] The utility model provides at least two limiting protrusions 62 at the lower part of the annular sealing ring 6 and at least two limiting protrusions 62 are respectively provided on both sides of the width direction of the connecting piece 42 so that the connecting piece 42 is embedded between two adjacent limiting protrusions 62 to limit the connecting piece 42 in the circumferential direction, thereby preventing the connecting piece 42 from rotating, and further preventing the bare battery cell 3 from rotating, thereby effectively preventing the bare battery cell 3 from rotating and impacting the welding point of the explosion-proof welding piece 22 on the upper part of the power battery 10 and the top cover welding piece 21 and the welding point of the bottom shell 11 of the power battery 10 and the negative electrode collector 5, thereby preventing the battery from opening and leaking.

[0028] In the embodiment of the utility model, the two adjacent limiting protrusions 62 located on both sides of the width direction of the connecting piece 42 are symmetrically arranged on both sides of the width direction of the connecting piece 42. Figure 8 As shown, by symmetrically arranging two adjacent limiting protrusions 62 on both sides of the connecting piece 42 in the width direction, the stability of the limiting can be improved and the limiting effect can be better.

[0029] In the embodiment of the utility model, the side wall of the limiting protrusion 62 close to the connecting piece 42 abuts against the side of the connecting piece 42. Specifically, the side wall of the limiting protrusion 62 close to the connecting piece 42 abuts against the side of the connecting piece 42 to ensure a better limiting effect, for example, Figure 4As shown, the difference between the distance W between two adjacent limiting protrusions 62 on both sides of the connecting piece 42 in the width direction and the width of the connecting piece 42 can be set to be greater than or equal to 0.05 mm and less than or equal to 0.2 mm so as to just clamp the side wall of the connecting piece 42.

[0030] In the embodiment of the utility model, Figure 8 As shown, the connecting piece includes a first end 43 connected to the disc-shaped body 41 and a second end 44 opposite to the first end 43. The limiting protrusions 62 include four, namely, a first protrusion 6211, a second protrusion 6212, a third protrusion 6213 and a fourth protrusion 6214. The first protrusion 6211 and the second protrusion 6212 are symmetrically arranged on both sides of the first end 43, and the third protrusion 6213 and the fourth protrusion 6214 are symmetrically arranged on both sides of the second end 44. By providing four limiting protrusions 62, and the limiting protrusions 62 are symmetrically distributed on the first end 43 and the second end 44, the limiting effect of the limiting protrusions 62 is further ensured. It should be noted that the number of the limiting protrusions 62 is not limited and can be adjusted according to actual needs.

[0031] In the embodiment of the utility model, Figure 3 and Figure 5 As shown, the cross-section of the limiting protrusion 62 is an inverted trapezoidal structure. Specifically, the limiting protrusion 62 includes a first side wall 622 that cooperates with the connecting piece 42, a second side wall 623 opposite to the first side wall 622, and a third side wall 624 and a fourth side wall 625 connected to the first side wall 622 and the second side wall 623. The third side wall 624 faces the outside of the power battery 10, and the fourth side wall 625 faces the inside of the power battery 10. The first side wall 622 is a vertical surface to abut against the side of the connecting piece 42, the second side wall 623 can be symmetrically arranged with the first side wall 622, and the third side wall 624 and the fourth side wall 625 are both arc surface structures with the center of the circle facing the inside of the power battery 10.

[0032] In some other specific implementations of the present utility model, such as Fig. 9 As shown, the cross-section of the limiting protrusion 62 is a U-shaped structure with an opening toward the outside. Specifically, the first side wall 622a cooperates with the connecting piece 42, the second side wall 623a is arranged opposite to the first side wall 622a, and the third side wall 624a is an arc surface recessed toward the fourth side wall 625a so that the cross-section of the limiting protrusion 62 is a U-shaped structure with an opening toward the outside, so that the first side wall 622a has more elastic deformation to facilitate the installation of the connecting piece 42.

[0033] In the embodiment of the utility model, the annular sealing ring 6 includes a sealing body 61 and a limiting protrusion 62 extending downward from the sealing body 61. The limiting protrusion 62 has a free end surface 621 away from the sealing body 61. The free end surface 621 is connected to the side surface of the limiting protrusion 62 through a guide chamfer 626. Specifically, as Figure 3 As shown, the guide chamfer 626 is a rounded corner or a C-angle. The setting of the guide chamfer 626 can facilitate the embedding installation of the connecting piece 42, and the design is ingenious.

[0034] In the embodiment of the utility model, the annular sealing ring 6 includes a sealing body 61 and a limiting protrusion 62 extending downward from the sealing body 61, the limiting protrusion 62 has a free end surface 621 away from the sealing body 61, and the distance between the free end surface 621 and the sealing body 61 is greater than or equal to 0.05 mm and less than or equal to 1.5 mm. Specifically, as Figure 4 As shown, the distance H between the free end surface 621 and the sealing body 61 is greater than or equal to 0.05 mm and less than or equal to 1.5 mm.

[0035] In the embodiment of the utility model, the annular sealing ring 6 is integrally injection molded. Specifically, the sealing body 61 and the limiting protrusion 62 are integrally injection molded, and the material of the annular sealing ring is a plastic material such as PBT, PP, etc.

[0036] The assembly method of the power battery 10 of the utility model is as follows: first, the middle part of the explosion-proof welding piece 22 and the middle part of the connecting piece 42 of the top cover 2 are pre-fixed by CID laser welding, and when the annular sealing ring 6 is injection-molded, a limiting protrusion 62 is integrally provided, and then the annular sealing ring 6 is pre-inserted into the top cover 2; at the same time, the collector plate 4 and the entire pole ear of the bare battery cell 3 are first fixed by laser welding; then the connecting piece 42 of the collector plate 4 is embedded in the preset adjacent limiting protrusion 62 of the annular sealing ring 6, and is fixed by laser welding with the top cover welding piece 21; then the top cover welding piece 21 is bent, and the top cover 2 is pressed down for assembly.

[0037] The above disclosure is only a preferred example of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A power battery, Features: It includes a shell, a top cover and a bare battery cell arranged inside the shell, the top cover closes the upper part of the shell, a current collecting plate is arranged at the upper end of the bare battery cell, the current collecting plate includes a disc-shaped body and a connecting piece extending and bent from one side of the disc-shaped body, the connecting piece is stacked above the disc-shaped body, an annular sealing ring is arranged between the shell and the top cover, the annular sealing ring is located above the disc-shaped body and the lower part of the annular sealing ring corresponds to the connecting piece and extends downward with at least two limiting protrusions, and the at least two limiting protrusions are respectively arranged on both sides of the connecting piece in the width direction to limit the rotation of the connecting piece.

2. The power battery according to claim 1, Features: The two adjacent limiting protrusions located on both sides of the connecting piece in the width direction are symmetrically arranged on both sides of the connecting piece in the width direction.

3. The power battery according to claim 2, Features: The limiting protrusion is close to the side wall of the connecting piece and abuts against the side of the connecting piece.

4. The power battery according to claim 2, Features: The connecting piece includes a first end connected to the disc-shaped body and a second end opposite to the first end. The limiting protrusions include four, namely a first protrusion, a second protrusion, a third protrusion and a fourth protrusion. The first protrusion and the second protrusion are symmetrically arranged on both sides of the first end, and the third protrusion and the fourth protrusion are symmetrically arranged on both sides of the second end.

5. The power battery according to claim 1, Features: The cross section of the limiting protrusion is an inverted trapezoidal structure or the cross section of the limiting protrusion is a U-shaped structure with the opening facing outward.

6. The power battery according to claim 1, Features: The annular sealing ring includes a sealing body and a limiting protrusion extending downward from the sealing body, wherein the limiting protrusion has a free end surface away from the sealing body, and the free end surface is connected to a side surface of the limiting protrusion via a guide chamfer.

7. The power battery according to claim 2, Features: The difference between the distance between two adjacent limiting protrusions located on both sides of the connecting piece in the width direction and the width of the connecting piece is greater than or equal to 0.05 mm and less than or equal to 0.2 mm.

8. The power battery according to claim 1, Features: The annular sealing ring includes a sealing body and a limiting protrusion extending downward from the sealing body, wherein the limiting protrusion has a free end surface away from the sealing body, and a distance between the free end surface and the sealing body is greater than or equal to 0.05 mm and less than or equal to 1.5 mm.

9. The power battery according to claim 1, Features: The annular sealing ring is integrally injection-molded.

10. The power battery according to claim 1, Features: The top cover also includes a top cover welding piece and an explosion-proof welding piece. The top cover welding piece is arranged above the connecting piece and is welded to the connecting piece. The explosion-proof welding piece is arranged above the top cover welding piece and is welded to the top cover welding piece.

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