CN219350555U

CN219350555U - Power battery shell

Info

Publication number: CN219350555U
Application number: CN202320718219.XU
Authority: CN
Inventors: 黎英岳; 李亚勇; 都守康
Original assignee: Shenzhen Everwin Precision Technology Co Ltd
Current assignee: Shenzhen Everwin Precision Technology Co Ltd
Priority date: 2023-03-28
Filing date: 2023-03-28
Publication date: 2023-07-14
Anticipated expiration: 2033-03-28

Abstract

The utility model provides a power battery casing is including the casing that is equipped with a plurality of surfaces and punching press formation explosion-proof piece on a surface, explosion-proof piece include certainly connecting portion that an inside sunken formation of surface punching press of casing, form in lamellar body in the connecting portion and processing form lamellar body periphery or the slot on the connecting portion, connecting portion are close to the one side of electric core and keep away from the one side of electric core on the equal shaping have the shape be annular slot, see from the cross-section like this lamellar body and connecting portion be V font structure, when the thickness of explosion-proof piece thickness in slot department is thinnest so that electric core internal pressure increases, V font structure pressurized is to middle stretching, V font structure bottom department stress is the biggest this moment, explosion-proof piece certainly slot department fracture pressure release. The explosion-proof sheet has good strength, no air tightness problem, simple production process and easy mass production.

Description

Power battery shell

Technical Field

The utility model relates to the field of power batteries, in particular to a power battery shell.

Background

At present, with the increasing capacity requirement of power batteries used by new energy vehicles, the power batteries often adopt battery cores with higher and higher nickel-containing proportion, and the high-energy battery cores are widely used in various transportation scenes. However, the battery core with high nickel content has high energy density, and in the practical use process of the power battery, the internal air pressure of the battery may rise to exceed a safety value due to short circuit or other reasons, so that hidden dangers such as explosion and the like are generated. To minimize the potential hazards, explosion-proof plates are generally provided on the battery cover plate, and currently, the explosion-proof plates are usually manufactured separately and then welded on the top cover or the battery shell by means of laser welding. And the welding is often accompanied with the defects of cracks, air holes, inclusions and the like, so that the air tightness and strength of a welding channel are greatly influenced, and the bad battery is easily caused. On the other hand, the current explosion-proof sheet raw materials come from abroad, the cost of a single sheet is high, and meanwhile, the cost of laser welding is relatively high, so that the problem of high production cost is caused.

In the prior art, researchers also propose to directly punch and process the explosion-proof valve integrated with the top cover sheet on the top cover sheet, so that a welding procedure is omitted, the safety performance of the top cover sheet can be ensured, and the assembly time for assembling the top cover sheet and the explosion-proof valve can be saved. For example, the secondary battery top cover disclosed in CN108461665a adopts a simple thinning design, and uses a thin wall thickness as a bursting point of the bursting disc, so as to realize the bursting function of the bursting disc when the internal air pressure of the battery is increased. Then, the processing technology of the explosion-proof sheet is complex, the problem of high production cost exists, and the industrialization of the integrated explosion-proof sheet is not facilitated. Accordingly, there is an urgent need to provide a new roof structure to solve the above-mentioned problems.

Disclosure of Invention

In view of the above, an object of the present utility model is to provide a power battery case in which an explosion-proof sheet is integrally formed on the battery case by pressing, so as to simplify the manufacturing process, improve the manufacturing efficiency, and reduce the cost of raw materials.

The utility model provides a power battery casing is including being equipped with the casing and the explosion proof piece of punching press formation on a surface of a plurality of surfaces, explosion proof piece include certainly connecting portion that an inside sunken formation of surface punching press of casing, form in lamellar body in the connecting portion and processing form lamellar body periphery or the slot on the connecting portion, the slot formation is in lamellar body or connecting portion are close to on the one side of electric core, and the thickness of explosion proof piece is thinnest in the thickness of slot department so that when electric core internal pressure increases suddenly, explosion proof piece certainly slot department fracture pressure release.

Preferably, the slot sets up simultaneously on the one side that the connecting portion is close to the electric core and on the one side that keeps away from the electric core, and the wall thickness of such slot is thinner, and the blasting is easier, and the designer can set up different decompression atmospheric pressures according to the inside pressure release demand of battery like this.

Preferably, the sheet body can be a convex curved surface according to actual conditions, the sheet body is convex towards the direction away from the battery cell, the area of the curved surface contacting the internal air is larger, the acting force of the internal air pressure on the groove is increased, and the blasting stability is improved.

In addition, the sheet body can be provided with the notch, the wall thickness of the notch part is weaker than that of the groove part, the notch is preferentially torn under the action of internal pressure, and then the groove is driven to tear together, so that the air pressure sensitivity can be improved.

According to the utility model, the explosion-proof sheet formed on one surface of the power battery shell is stamped, in the stamping forming process, by utilizing the flowing characteristic of metal, the material on the connecting part is stretched, so that the wall thickness of the connecting part is reduced, then a groove with thinner wall thickness is formed on one surface of the connecting part, which is close to the battery core, by matching with the die, in order to facilitate understanding, the sheet body and the connecting part are in a V-shaped structure when seen from the section, and the annular groove is formed on one surface, which is close to the battery core, at the bottom of the V-shaped structure, when the internal air pressure is increased, the V-shaped structure is stretched towards the middle under compression, at the moment, the stress at the bottom of the V-shaped structure is maximum, and the groove is easy to generate shearing stress concentration and tear rapidly, so that explosion is formed, and the internal pressure is released.

The stress condition of the explosion-proof sheet in the actual explosion process is considered, in the explosion process, the bottom shearing force stress caused by deformation of the two sides of the V-shaped structure is concentrated, and only one notch is arranged at the stress concentration part, so that the V-shaped structure can be torn rapidly, the failure of the explosion-proof sheet is realized, and the explosion-proof sheet can be just used as an explosion form on the explosion-proof sheet of a battery.

In addition, the notch is arranged on the sheet body and is in linkage explosion with the groove, so that the pressure sensitivity of the integrated explosion-proof sheet can be increased.

The explosion-proof sheet has the advantages of good overall strength of the battery, no air tightness, simple process in processing aspect and suitability for industrialization.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is a schematic view of a power cell top cover having the present utility model;

FIG. 2 is a cross-sectional view of a rupture disc formed in a cover sheet;

FIG. 3 is another alternative cross-sectional view of a rupture disc formed in a cover sheet;

FIG. 4 is another alternative cross-sectional view of a rupture disc formed in the cover sheet;

FIG. 5 is a schematic view of a prismatic battery case having the present utility model;

FIG. 6 is a cross-sectional view of a rupture disc formed on a square battery housing;

FIG. 7 is a schematic view of a cylindrical battery housing having the present utility model;

fig. 8 is a cross-sectional view of a rupture disc molded in place on a cylindrical battery housing.

The specification reference numerals are as follows:

the cover sheet 1, the rupture disc 11, the base 111, the connecting portion 112, the sheet body 113, the groove 114, the square battery case 2, the rupture disc 21, the body 22, the opening 23, the base 211, the connecting portion 212, the sheet body 213, the groove 214, the score 215, the rupture disc 31, the cylindrical battery case 3, the body 32, the opening 33, the score 315, the base 311, the connecting portion 312, the sheet body 313, and the groove 314.

Detailed Description

For the purposes, technical solutions and advantages of the present application, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The battery shell refers to an external component used for sealing an electric core in a battery, and can be a top cover or a battery shell, wherein the battery shell is of a semi-closed structure and is provided with at least one opening.

The power battery case and the molding method thereof according to the present utility model will be described in further detail by the following embodiments:

example 1

Referring to fig. 1, the power battery housing of the present application is a power battery top cover in embodiment 1, and the power battery top cover includes a top cover sheet 1 and an explosion-proof sheet 11 integrally formed on the top cover sheet 1. With continued reference to fig. 2, the rupture disc 11 includes a connecting portion 112 formed by punching and bending inwards from the top cover 1, a sheet 113 formed in the middle of the connecting portion 112, and a groove 114 cut into the periphery of the sheet 113 or the connecting portion 112. The connection portion 112 is an inclined surface.

Preferably, the groove 114 is a closed loop structure, and is formed at the junction of the sheet 112 and the connecting portion 112 by punching. The grooves 114 may be punched only on the outer surface or the lower surface or the upper and lower surfaces of the sheet 112 while the grooves 114 are punched.

Preferably, the grooves 114 are punched on the surface of the connection part 112, and the grooves 114 corresponding to each other can be punched on the upper and lower surfaces of the connection part 112 at the same time. The rupture disc 11 further comprises a base 111, a connecting portion 112 and a sheet body 113, wherein the base 111 is a top cover sheet body of the rupture disc 11, the connecting portion 112 is an annular area dividing base 111 and the sheet body 113, the base 111, the connecting portion 112 and the sheet body 113 are integrally formed, and an included angle between the connecting portion 112 and a tangential direction of a starting point of the sheet body 113 is 120 degrees.

The connecting portion 112 is formed with a ring-shaped groove 114 on a surface close to the battery cell, the groove 114 is recessed inward relative to the surface of the connecting portion 112, and the wall thickness of the connecting portion 112 is smaller than that of the base portion 111, so that the wall thickness of the groove 114 on the connecting portion 112 is minimum.

When the internal air pressure is increased, the V-shaped structure is pressed and stretched to the middle, and the stress at the bottom of the V-shaped structure is maximum, and the grooves are easy to generate shearing stress concentration and tear rapidly to form blasting, so that the internal pressure is released, and the internal high-pressure air is effectively discharged.

Example 2

In another aspect, referring to the cross section of another rupture disk 11 shown in fig. 3, the rupture disk 11 includes a base 111, a connecting portion 112, and a sheet 113, the base 111 is a top cover body of the rupture disk 11, the connecting portion 112 is an annular area dividing the base 111 and the sheet 113, the base 111, the connecting portion 112, and the sheet 113 are integrally formed, a groove 114 having a ring shape is formed on a surface of the connecting portion 112 of the rupture disk 11 near the battery core and a surface of the connecting portion far from the battery core, the groove 114 is recessed inward relative to a surface of the connecting portion 112, a wall thickness of a portion of the connecting portion 112 is smaller than a wall thickness of a portion of the base 111, so that a wall thickness of a portion of the groove 114 on the connecting portion 112 is minimum, and the groove 114 can be preferentially torn under an internal pressure.

Unlike embodiment 1, the grooves 114 are disposed on both sides of the connection portion 112, so that the sheet 113 and the connection portion 112 have a V-shaped structure when viewed in cross section, the annular groove formed on the side of the connection portion 112 close to the cell is located at the bottom of the V-shaped structure, and the annular groove formed on the side of the connection portion 112 away from the cell is located at the inner side of the included angle of the bottom of the V-shaped structure. The connecting portion 112 has an angle of 95 ° with respect to the tangential direction of the starting point of the sheet 113.

When the internal air pressure rises, the V-shaped structure is pressed and stretched towards the middle, at the moment, the stress at the bottom of the V-shaped structure is maximum, the deformation of the V-shaped structure can be allowed to be larger by the groove at the inner side, the groove at the outer side enables the bottom of the V-shaped structure to be easier, so that shearing stress concentration and rapid tearing are generated, blasting is formed, internal pressure is released, and internal high-pressure air is effectively discharged. The wall thickness at the position of the groove 114 is thinner, the explosion-proof sheet 11 is easier to explode, and thus, a designer can set different pressure relief air pressures according to the pressure relief requirement inside the battery.

Example 3

In another aspect, referring to the cross section of another rupture disk 11 as shown in fig. 4, the rupture disk 11 includes a base 111, a connecting portion 112, and a sheet body 113, the base 111 is a top cover body of the rupture disk 11, the connecting portion 112 is an annular region dividing the base 111 and the sheet body 113, the base 111, the connecting portion 112, and the sheet body 113 are integrally formed, the sheet body 113 protrudes in a direction away from the battery cell, and an angle between the connecting portion 112 and a tangential direction of a starting point of the sheet body 113 is 60 °. The connecting part 112 of the explosion-proof sheet 11 is provided with a ring-shaped groove 114 formed on one surface close to the battery cell, the groove 114 is recessed inwards relative to the surface of the connecting part 112, so that the sheet body 113 and the connecting part 112 are in a V-shaped structure when seen from the section, and the ring-shaped groove is formed on one surface of the connecting part 112 close to the battery cell and is positioned at the bottom of the V shape.

The sheet 113 protrudes away from the battery cell to form an arch structure, the surface area of the sheet 113 is larger, the acting area of the internal air pressure acting on the V-shaped structure is larger, the generated acting force is larger, so that the stress transferred to the groove is larger, the groove is easier to tear,

the included angle between the connecting portion 112 and the tangent direction of the starting point of the sheet 113 is 60 degrees, the bottom of the V-shaped structure is more stressed, and the explosion point is easier to be reached.

This arrangement increases the sensitivity of the rupture disk 11 to the internal gas pressure of the battery and increases the stability of the rupture.

Example 4

Referring to fig. 5, the power battery is a square battery housing 2, the square battery housing includes an explosion-proof sheet 21 integrally formed on any one or more outer walls of the square battery housing 2, the square battery housing 2 further includes a body 22 and an opening 23, and the opening 23 can be matched with a top cover sheet to seal the square battery housing 2. With reference to fig. 6, the cross section of the explosion-proof sheet 21 includes a base 211, a connecting portion 212, and a sheet 213, where the base 211 is a body 22 on one side of the square battery case 2 where the explosion-proof sheet 21 is located, the connecting portion 212 is an annular area dividing the base 211 and the sheet 213, the base 211, the connecting portion 212, and the sheet 213 are integrally formed, grooves 214 with annular shapes are formed on a side of the connecting portion 212 close to the battery core and a side far from the battery core, the grooves 214 are recessed inward relative to the surface of the connecting portion 212, and an included angle between the connecting portion 112 and a tangential direction of a starting point of the sheet 113 is 120 °.

Such a sheet 213 and the connection portion 212 have a V-shaped structure when viewed in cross section, and the annular groove formed in the side of the connection portion 212 adjacent to the cell is located at the bottom of the V-shape. When the internal air pressure is increased, the V-shaped structure is pressed and stretched towards the middle, at the moment, the stress at the bottom of the V-shape is maximum, and the groove is easy to generate shearing stress concentration and tear rapidly to form explosion, so that the internal pressure is released, and the internal high-pressure air is effectively discharged.

The sheet 213 also has a notch 215, the wall thickness of the notch 215 is weaker than that of the groove 213, the notch 215 is preferentially torn under the action of internal pressure, and then the groove 214 is driven to be torn together, so that the sensitivity of the explosion-proof sheet 21 to air pressure can be improved.

In addition, can also be according to the design demand, will sheet 213 shaping is protruding to the direction of keeping away from the electric core, forms the arch structure for the effect of inside atmospheric pressure is bigger in the area of sheet 213, can make like this transfer to the stress of slot is bigger, and such setting has improved the sensitivity of explosion-proof piece 21 to the inside atmospheric pressure of battery improves the stability of blasting.

Example 5

Referring to fig. 7, the power battery is a cylindrical battery housing 3, the square cylindrical battery housing 3 includes an explosion-proof sheet 31 integrally formed at the bottom of the cylindrical battery housing 3, the cylindrical battery housing 3 further includes a body 32 and an opening 33, the opening 33 can be matched with a top cover sheet to seal the cylindrical battery housing 3, and the explosion-proof sheet 31 is further formed with a notch 315. Referring to fig. 8, the cross section of the explosion-proof sheet 31 is shown in fig. 8, the explosion-proof sheet 31 includes a base 311, a connecting portion 312, and a sheet 313, the base 311 is a body of the bottom surface of the cylindrical battery case 3 where the explosion-proof sheet 21 is located, the connecting portion 312 is an annular region dividing the base 311 and the sheet 313, the base 311, the connecting portion 312, and the sheet 313 are integrally formed, the surface of the connecting portion 312, which is close to the battery core, and the surface, which is far away from the battery core, are both formed with annular grooves 314, and the grooves 314 are recessed inwards relative to the surface of the connecting portion 312. The connecting portion 312 has an angle of 60 ° with respect to the tangential direction of the start point of the sheet 313.

Such from the cross-section, the sheet 313 and the connecting portion 312 are in a V-shaped structure, the annular groove formed on the surface of the connecting portion 312 close to the battery cell is located at the bottom of the V-shaped structure, and the annular groove formed on the surface of the connecting portion 312 far from the battery cell is located at the inner side of the included angle of the bottom of the V-shaped structure.

When the internal air pressure rises, the V-shaped structure is pressed and stretched towards the middle, at the moment, the stress at the bottom of the V-shaped structure is maximum, the deformation of the V-shaped structure can be allowed to be larger by the grooves on the inner side, the bottom of the V-shaped structure is enabled to be easier to generate shearing stress concentration and tear rapidly by the grooves on the outer side, blasting is formed, the internal pressure is released, and the internal high-pressure air is effectively discharged. The angle between the connecting portion 312 and the tangent direction of the starting point of the sheet 313 is 60 °, the bottom of the V-shaped structure is more stressed, and the explosion point is more easily reached.

A score 315 is formed on the sheet 313, and the wall thickness of the score 315 is weaker than that of the groove 313, so that the score 315 is preferentially torn under the action of internal pressure and then drives the groove 314 to be torn together, thus the sensitivity of the explosion-proof sheet 31 to air pressure can be improved.

Claims

1. The utility model provides a power battery casing, includes the casing that is equipped with a plurality of surfaces and the explosion-proof piece of punching press formation on a surface, its characterized in that, explosion-proof piece include from the connecting portion that an inside sunken formation of casing surface punching press, form in connecting portion the lamellar body and processing form in lamellar body periphery or the slot on the connecting portion, the thickness of explosion-proof piece is in when the thickness of slot department is thinnest so that the pressure surge in electric core, explosion-proof piece is followed slot department fracture pressure release.

2. A power cell housing according to claim 1, wherein the connection portion is formed with an annular groove on a side thereof remote from the cell.

3. The power cell housing of claim 1, wherein the tab projects away from the cell to form an arch.

4. A power cell housing according to claim 1, wherein said sheet is further formed with a score, said score portion having a wall thickness less than a wall thickness of said channel portion.

5. A power cell housing according to claim 1, wherein the surface is a power cell top cover substrate or a square cell housing outer wall or a circular cell bottom surface.

6. A power cell housing according to claim 1, wherein the angle between the connecting portion and the tangent to the starting point of the sheet is 60-120 °.