Insulating sheet of power battery and power battery

Abstract

The invention discloses an insulating sheet of a power battery and the power battery. The insulation sheet is configured to be arranged at the first end of a roll core of the power battery, the first end is configured to be arranged at the shell bottom of the power battery, and the insulation sheet is characterized by comprising a bottom plate, the bottom plate comprises a first surface and a second surface which are oppositely arranged, and the first surface extends out of an extension part opposite to the second surface; the extension part is provided with a slag prevention hole penetrating from the tail end surface of the extension part to the second surface, the first surface is configured to be attached to the end surface of the first end, the second surface is configured to be attached to a tab of the roll core, and the extension part is configured to be inserted into a center hole of the roll core. The side wall of the anti-slag hole can block welding slag generated by the welding jig during welding, and the situation that splashing welding slag melts through the diaphragm on the side wall of the center hole, and consequently short circuit occurs in the battery is avoided.

Description

Technical Field

[0001] This application relates to the field of batteries, and particularly to insulating sheets and power batteries. Background Art

[0002] Existing power batteries include a housing, an insulating sheet, and a wound core. When assembling a power battery, the tab of the wound core is often welded and fixed to the bottom of the housing of the power battery by means of resistance spot welding. During welding, a welding jig passes through the central hole of the wound core and the welding hole of the insulating sheet to weld and fix the tab of the wound core to the bottom of the housing. However, the welding slag generated by the welding jig is likely to splash onto the side wall of the central hole of the battery, and the splashed welding slag is likely to melt through the separator, resulting in an internal short circuit, scrapping of the wound core, and even thermal runaway. Summary of the Invention

[0003] The purpose of this application is to provide an insulating sheet and a power battery, aiming to solve the technical problem that during welding, the splashed welding slag is likely to melt through the separator and cause an internal short circuit as described in the background art.

[0004] To achieve the above purpose, this application provides an insulating sheet for a power battery. The insulating sheet is configured to be disposed at the first end of the wound core of the power battery, and the first end is configured to be disposed at the bottom of the housing of the power battery. The insulating sheet includes a bottom plate, and the bottom plate includes a first surface and a second surface that are oppositely disposed. The first surface extends out an extension portion away from the second surface, and the extension portion is provided with a slag-proof hole that penetrates from the end surface of the extension portion to the second surface. The first surface is configured to be attached to the end surface of the first end, the second surface is configured to be attached to the tab of the wound core, and the extension portion is configured to be inserted into the central hole of the wound core.

[0005] The insulating sheet of this application includes a bottom plate. The bottom plate includes a first surface and a second surface that are oppositely disposed. The first surface extends out an extension portion away from the second surface, and the extension portion is provided with a slag-proof hole that penetrates from the end of the extension portion to the second surface. The first surface is configured to be fixed to the end surface of the first end, the second surface is configured to be attached to the tab of the wound core, and the extension portion is configured to be inserted into the central hole of the wound core. During welding, the welding jig passes through the central hole of the wound core and the slag-proof hole to weld the tab of the wound core to the bottom of the battery. Among them, the side wall of the slag-proof hole can block the welding slag generated during welding by the welding jig, preventing the splashed welding slag from melting through the separator on the side wall of the central hole and causing an internal short circuit of the battery.

[0006] Optionally, the side wall of the extension portion is configured to be attached to the side wall of the central hole.

[0007] Optionally, the edge of the first surface is configured to be substantially adapted to the edge of the end surface of the first end.

[0008] Optionally, the extension is substantially cylindrical.

[0009] Optionally, the raw material of the extension includes high-temperature resistant insulating resin.

[0010] To achieve the above object, the present application further provides a power battery, including a housing, a wound core, and the above-mentioned insulating sheet. The first surface of the bottom plate of the insulating sheet is fixed to the end face of the first end of the wound core, the extension of the insulating sheet is inserted into the central hole of the wound core, the tab of the wound core is arranged in contact with the second surface of the bottom plate, and the surface of the tab facing away from the second surface is fixedly welded to the bottom of the housing.

[0011] Optionally, one end of the tab is arranged on one side of the wound core, the other end of the tab extends towards the first end of the wound core, and is bent and attached to the second surface of the bottom plate.

[0012] Optionally, the tab is the negative tab of the wound core. Description of the Drawings

[0013] Figure 1 It is a three-dimensional structural schematic diagram of the insulating sheet according to an embodiment of the present application.

[0014] Figure 2 It is another three-dimensional structural schematic diagram of the insulating sheet according to an embodiment of the present application.

[0015] Figure 3 It is Figure 1 the cross-sectional view taken along line A-A in

[0016] Figure 4 It is a schematic diagram of welding the tab on the bottom of the housing according to an embodiment of the present application.

[0017] Figure 5 It is a three-dimensional structural schematic diagram of the insulating sheet of the prior art.

[0018] Figure 6 It is Figure 5 the cross-sectional view taken along line B-B in

[0019] Figure 7 It is a schematic diagram of welding the tab of the prior art on the bottom of the housing. Detailed Embodiments

[0020] To describe in detail the technical content, structural features, achieved objects and effects of the present application, the following is described in detail in conjunction with the embodiments and with reference to the drawings.

[0021] Please refer to Figures 5 to 7, the existing insulating sheet A100 includes a bottom plate A1, and welding holes A2 penetrating both sides of the bottom plate A1 are formed on the bottom plate A1. The insulating sheet A100 is configured to be disposed at the first end 201 of the core 200, and the first end 201 is configured to be disposed at the bottom 301 of the housing 300. The welding holes A2 are correspondingly arranged with the central hole 202 of the core 200. During welding, the welding jig H1 passes through the central hole 202 and the welding holes A2, and the tab 203 of the core 200 is welded and fixed to the bottom 301. Since the welding slag H2 generated during the welding of the welding jig H1 is likely to splash onto the diaphragm (not shown) on the side wall of the central hole 202, the diaphragm is melted through, resulting in a short circuit inside the battery, the core 200 is scrapped, and even the thermal runaway of the battery is caused.

[0022] For this, please refer to Figures 1 to 4 , this application discloses an insulating sheet 100 for a power battery. The insulating sheet 100 is configured to be disposed at the first end 201 of the core 200 of the battery, and the first end 201 is configured to be disposed at the bottom 301 of the battery housing. Among them, the insulating sheet 100 includes a bottom plate 1. The bottom plate 1 includes a first surface 11 and a second surface 12 arranged opposite to each other. An extension portion 2 extends from the first surface 11 away from the second surface 12. A slag-proof hole 3 penetrating from the end of the extension portion 2 to the second surface 12 is formed in the extension portion 2. The first surface 11 is configured to be attached to the end face of the first end 201, the second surface 12 is configured to be attached to the tab 203 of the core 200, and the extension portion 2 is configured to be inserted into the central hole 202 of the core 200.

[0023] During welding, the welding jig H1 passes through the central hole 202 of the core 200 and the slag-proof hole 3, and the tab 203 of the core 200 is welded to the bottom 301 of the battery. Among them, the side wall of the slag-proof hole 3 can block the welding slag H2 generated during the welding of the welding jig H1, preventing the splashed welding slag H2 from melting through the diaphragm on the side wall of the central hole 202, resulting in a short circuit inside the battery.

[0024] In some embodiments, the side wall of the extension portion 2 is configured to be attached to the side wall of the central hole 202 to facilitate the welding jig H1 to pass through the slag-proof hole 3.

[0025] In some embodiments, the edge of the first surface 11 of the insulating sheet 100 is configured to be substantially adapted to the edge of the end face of the first end 201.

[0026] In some embodiments, the extension portion 2 is generally cylindrical. Of course, it is not limited to this.

[0027] In some embodiments, the raw material of the extension portion 2 includes high-temperature resistant insulating resin, such as polyethylene terephthalate (PET), polypropylene (PP), aramid paper, etc. Of course, it is not limited to this.

[0028] Please refer to Figures 1 to 4, this application also discloses a power battery, including a housing 300, a winding core 200, and the above-mentioned insulating sheet 100. The first surface 11 of the bottom plate 1 of the insulating sheet 100 is fixed to the end face of the first end 201 of the winding core 200, and the extending portion 2 of the insulating sheet 100 is inserted into the central hole 202 of the winding core 200. The tab 203 of the winding core 200 is disposed in contact with the second surface 12 of the bottom plate 1 of the insulating sheet 100, and the surface of the tab 203 facing away from the second surface 12 is welded and fixed to the bottom 301 of the housing 300.

[0029] In some embodiments, one end of the tab 203 is disposed on one side of the winding core 200, and the other end of the tab 203 extends toward the first end 201 of the winding core 200 and is bent and attached to the second surface 12 of the insulating sheet 100.

[0030] Specifically, the tab 203 is the negative tab of the winding core 200. Of course, it is not limited thereto. For example, if the positive tab of the winding core 200 actually needs to pass through the central hole 202 for welding and fixing, the tab 203 can also be the positive tab.

[0031] Combined with the embodiments, the following briefly describes part of the assembly process of the power battery: S1, dispose the bottom plate 1 of the insulating sheet 100 on the end face of the first end 201 of the winding core 200, insert the extending portion 2 of the insulating sheet 100 into the central hole 202 of the winding core 200, and dispose the tab 203 on the side of the bottom plate 1 facing away from the winding core 200.

[0032] S2, insert the winding core 200 into the housing 300 and make the first end 201 of the winding core 200 face the bottom 301 of the housing 300.

[0033] S3, pass the welding jig H1 through the central hole 202 and the slag prevention hole 3.

[0034] S4, use the welding jig H1 to weld the tab 203 to the bottom 301.

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

Claims

1. An insulating sheet of a power battery, the insulating sheet being configured to be arranged at a first end of a winding core of the power battery, the first end being configured to be arranged at a shell bottom of the power battery, characterized in that: The insulating sheet includes a base plate, the base plate includes a first surface and a second surface arranged opposite to each other, the first surface extends an extension portion away from the second surface, the extension portion is provided with a slag prevention hole extending from the end surface of the extension portion to the second surface, the first surface is configured to be fitted to the end surface of the first end, the second surface is configured to be fitted to the pole ear of the winding core, and the extension portion is configured to be inserted into the center hole of the winding core.

2. The insulating sheet according to claim 1, wherein: The side wall of the extension portion is configured to fit with the side wall of the central hole.

3. The insulating sheet according to claim 1, wherein: The edge of the first face is configured to substantially match the edge of the end face of the first end.

4. The insulating sheet according to claim 1, wherein: The extension portion is substantially cylindrical.

5. The insulating sheet according to claim 1, wherein: The raw material of the extension portion includes high temperature resistant insulating resin.

6. A power battery, characterized in that: It comprises a shell, a winding core and an insulating sheet as described in any one of claims 1 to 5, wherein the first surface of the base plate of the insulating sheet is fixed to the end surface of the first end of the winding core, the extension portion of the insulating sheet is inserted into the central hole of the winding core, the pole ear of the winding core is arranged to fit the second surface of the base plate, and the side of the pole ear facing away from the second surface is welded and fixed to the shell bottom of the shell.

7. The power battery according to claim 6, characterized in that: One end of the pole lug is arranged on one side of the winding core, and the other end of the pole lug extends toward the first end of the winding core and is bent and attached to the second surface of the bottom plate.

8. The power battery according to claim 7, characterized in that: The electrode tab is a negative electrode tab of the winding core.

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