CN221226397U

CN221226397U - Battery cell

Info

Publication number: CN221226397U
Application number: CN202322807307.XU
Authority: CN
Inventors: 赵冬
Original assignee: China Innovation Aviation Technology Group Co ltd
Current assignee: China Innovation Aviation Technology Group Co ltd
Priority date: 2023-10-18
Filing date: 2023-10-18
Publication date: 2024-06-25
Anticipated expiration: 2033-10-18

Abstract

The application provides a battery, which comprises a shell, wherein one side of the shell is provided with an opening; the cover plate is fixedly connected with the shell and is used for sealing the opening; the battery cell is arranged in the shell; the shell comprises a metal layer, a first insulating layer and a second insulating layer which are integrally formed, wherein the first insulating layer covers the surface of the metal layer facing the battery cell, and the second insulating layer covers the surface of the metal layer facing away from the battery cell; the thickness d1 of the first insulating layer and the thickness d2 of the second insulating layer satisfy: d1 And d2 is not less than. In the technical scheme, the working procedure of battery assembly is simplified, the working efficiency is improved, the space utilization rate is improved, the space occupying the internal battery cell is reduced, and the energy density of the battery is improved; in addition, the problem that the first insulating layer positioned on the inner side breaks at the corner is avoided, and the first insulating layer has stronger corrosion resistance; in addition, the problem of thermal runaway damage of the battery caused by too low heat transmission rate between the batteries is avoided.

Description

Battery cell

Technical Field

The application relates to the technical field of batteries, in particular to a battery.

Background

The existing battery structure comprises a shell and a battery cell fixed in the shell, wherein the shell is made of metal materials, and insulation is required to be kept between the battery cell and the shell; the insulating film is wrapped on the outer side of the battery cell in a conventional manner.

In the existing structure, the insulating film is wrapped outside the battery cell, so that the assembly efficiency of the battery can be influenced, the space occupied in the shell can be increased, and the space utilization rate of the battery can be reduced.

Disclosure of utility model

The application provides a battery which is used for improving the space utilization rate of the battery and improving the assembly efficiency of the battery.

The present application provides a battery, comprising,

A shell, wherein one side of the shell is provided with an opening;

the cover plate is fixedly connected with the shell and is used for sealing the opening;

the battery cell is arranged in the shell;

The shell comprises a metal layer, a first insulating layer and a second insulating layer which are integrally formed, wherein the first insulating layer covers the surface of the metal layer facing the battery cell, and the second insulating layer covers the surface of the metal layer facing away from the battery cell;

the thickness d1 of the first insulating layer and the thickness d2 of the second insulating layer satisfy: d1 And d2 is not less than.

In the technical scheme, the shell comprises the metal layer, the first insulating layer and the second insulating layer which are integrally formed, so that the process of assembling the battery is simplified, and the working efficiency is improved; on the other hand, compared with a mode of independently arranging the insulating structure, the first insulating layer and the second insulating layer occupy less space, so that the space utilization rate is improved, the space occupying an internal electric core is reduced, and the energy density of the battery is improved; in addition, the thickness of the first insulating layer is larger than that of the second insulating layer, so that the problem that the first insulating layer positioned on the inner side breaks at the corner is avoided in the process of stamping or stretching and forming the raw material of the metal layer; in addition, electrolyte is injected into the battery at the subsequent time, and the electrolyte has certain corrosiveness, so that the thickness of the first insulating layer arranged on the inner side is larger, the corrosion resistance is stronger, the stability of the structural function of the battery is improved, and the service life is prolonged; meanwhile, the problem of overlarge thickness of the second insulating layer can be avoided, and the problem of slower heat transfer rate between batteries caused by overlarge thickness of the insulating layer can be avoided; under the state that a plurality of batteries are assembled to form the battery package, the heat that single battery work produced can be timely give off to the group battery outside via other batteries, avoids the heat transmission rate between the battery too low, causes the problem of battery thermal runaway damage, promotes battery quality.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a battery according to an embodiment of the present application;

Fig. 2 is a schematic structural diagram of a housing according to an embodiment of the present application;

Fig. 3 is a schematic structural diagram of a battery cell according to an embodiment of the present application.

Reference numerals illustrate: 1. a housing; 11. a metal layer; 12. a first insulating layer; 13. a second insulating layer; 14. arc-shaped corners; 2. a cover plate; 3. a battery cell; 31. a positive plate; 32. a negative electrode sheet; 33. a diaphragm.

Detailed Description

The application is further described in detail below by means of the figures and examples. The features and advantages of the present application will become more apparent from the description.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In addition, the technical features described below in the different embodiments of the present application may be combined with each other as long as they do not collide with each other.

In order to facilitate understanding of the battery provided by the embodiment of the application, a battery structure is briefly described first, the existing battery comprises a shell and a battery core fixed in the shell, and an insulating film is coated on the outer side of the battery core to realize insulation between the battery core and the shell; however, the battery of such a structure may cause problems in that the efficiency of assembly is low, and a large space is occupied inside the battery, resulting in a reduction in space utilization of the battery, resulting in a reduction in energy density of the battery. The embodiment of the application provides a battery, which is used for improving the assembly efficiency of the battery, reducing the space waste and improving the energy density of the battery. The following detailed description is made with reference to the specific drawings and examples.

Referring to fig. 1, fig. 1 shows a schematic structure of a battery according to an embodiment of the present application. The battery provided by the embodiment of the application comprises a shell 1, a cover plate 2 and a battery cell 3, wherein one side of the shell 1 is provided with an opening, the cover plate 2 is fixedly connected with the shell 1 to seal the opening of the shell 1, and a cavity isolated from the outside is formed inside the shell 1; the battery cell 3 is arranged in the shell 1 and fixedly connected with the shell 1.

Referring to fig. 2, the housing 1 includes a metal layer 11, a first insulating layer 12, and a second insulating layer 13 integrally formed, wherein the first insulating layer 12 covers a surface of the metal layer 11 facing the battery cell 3, and the second insulating layer 13 covers a surface of the metal layer 11 facing away from the battery cell 3; i.e. the first insulating layer 12 is located inside the metal layer 11 and the second insulating layer 13 is located inside the metal layer 11. The thickness of the first insulating layer 12 is d1, the thickness of the second insulating layer 13 is d2, and d1 and d2 satisfy: d1 D2 is more than or equal to 0.08mm and d1 is more than or equal to 0.15mm.

The metal layer 11, the first insulating layer 12, and the second insulating layer 13 defined in the embodiment of the present application are integrally formed, which means that the first insulating layer 12 and the second insulating layer 13 are disposed when the housing 1 is formed by processing. In an initial state, the metal layer 11 is of a plate-shaped structure, and the first insulating layer 12 and the second insulating layer 13 are formed by spraying and coating raw materials on the surface of the metal layer 11 or bonding and fixing a film-shaped structure made of corresponding materials on the surface of the metal layer 11; the metal layer 11 is then stamped or drawn into the shell 1.

By arranging the first insulating layer 12, the second insulating layer 13 and the metal layer 11 to be integrally formed, the inner and outer insulating arrangement of the metal layer 11 can be completed simultaneously in the process of processing the raw material of the metal layer 11 and forming the shell 1; in this way, in the state that the battery cell 3 is fixed in the housing 1 later, the insulating film is not required to be coated outside the battery cell 3, or insulating substances are filled between the battery cell 3 and the side wall of the housing 1, so that the insulating treatment between the battery cell 3 and the housing 1 is realized.

On one hand, the working procedure of battery assembly is simplified, and the working efficiency is improved; on the other hand, compared with the mode of independently arranging the insulating structures, the first insulating layer 12 and the second insulating layer 13 arranged in the application occupy less space, so that the space utilization rate is improved, the space occupied by the internal battery cell 3 is reduced, and the energy density of the battery is improved.

In addition, the thickness of the first insulating layer 12 is larger than that of the second insulating layer 13, so that the problem that the first insulating layer 12 positioned on the inner side breaks at the corner is avoided in the process of stamping or stretching the raw material of the metal layer 11; and, can pour into electrolyte in the battery inside at the follow-up, electrolyte has certain corrosivity, therefore it is bigger to set up the first insulating layer 12 thickness that is located the inboard, has stronger corrosion resistance, promotes battery structural function's stability, increase of service life.

Meanwhile, the problem of overlarge thickness of the second insulating layer 13 can be avoided, and the problem of slower heat transfer rate between batteries caused by overlarge thickness of the insulating layer is avoided; under the state that a plurality of batteries are assembled to form the battery package, the heat that single battery work produced can be timely give off to the group battery outside via other batteries, avoids the heat transmission rate between the battery too low, causes the problem of battery thermal runaway damage, promotes battery quality.

The metal layer 11 is made of aluminum or aluminum alloy, the first insulating layer 12 is made of aluminum oxide, silicon carbide, etc., and the second insulating layer 13 is made of ABS plastic, PP, PE, etc. Of course, the embodiment of the application is to make an exemplary description on optional materials, and in other embodiments, suitable materials may be selected according to the needs; but it is ensured that the materials of the first insulating layer 12 and the second insulating layer 13 are insulated.

Specifically, the thickness d1 of the first insulating layer 12 and the thickness d2 of the second insulating layer 13 satisfy: d1/d2 is more than or equal to 1.1 and less than or equal to 1.5.

If the ratio of the two is too small, it indicates that the thickness of the first insulating layer 12 is relatively smaller, which increases the risk of failure of the first insulating layer 12; if the ratio of the two is too large, the thickness of the first insulating layer 12 is relatively large, more space inside the shell 1 is occupied, the space utilization rate is reduced, and the energy density of the battery is reduced to a certain extent; in addition, if the thickness of the insulating layer is too large, the heat transfer rate of the casing 1 is also greatly reduced, and the working heat generated by the battery cell 3 cannot be timely and quickly transferred, so that the probability of thermal runaway of the battery cell 3 is increased.

Correspondingly, the ratio of the thickness of the first insulating layer 12 to the thickness of the second insulating layer 13 is limited within a corresponding range, so that the problem of insulation failure of the first insulating layer 12 can be reduced, and the stability of the insulating performance of the battery is improved; the reduction occupies casing 1 inner space, improves space utilization, and the energy density of battery is higher, and casing 1's heat transfer rate is also faster, and battery core 3 produces timely, quick outgoing, promotes battery job stabilization nature, increase of service life.

Further, the thickness of the metal layer 11 is d3, and d3, d1 and d2 satisfy the following relationship: d3/d1 is more than or equal to 3 and less than or equal to 18, or d3/d2 is more than or equal to 3 and less than or equal to 18.

In the embodiment of the application, the structural strength of the whole shell 1 is realized by the metal layer 11, so that the thickness of the metal layer 11 determines the structural strength of the shell 1 under the condition that the material selected for the metal layer 11 is determined; if the thickness of the metal layer 11 is too small, the structural strength of the shell 1 is insufficient, and the problems of deformation and damage are easily caused; the heat conductive properties of the first insulating layer 12 and the second insulating layer 13 are lower than those of the metal layer 11, and if the thicknesses of the first insulating layer 12 and the second insulating layer 13 are larger than those of the metal layer 11, the heat transfer rate of the case 1 is lowered.

In addition, if the thickness of the metal layer 11 is too large, it indicates that the thickness of the first insulating layer 12 or the second insulating layer 13 is too small relative to the metal layer 11, so that the risk of insulation failure caused by structural damage of the first insulating layer 12 and the second insulating layer 13 is greatly increased.

Therefore, by limiting the thickness of the metal layer 11, the thickness of the metal layer 11 is kept in a proper range, and in proper proportional relation with the thicknesses of the first insulating layer 12 and the second insulating layer 13, the structural strength of the casing 1 can be ensured to be high enough, and stable support and protection effect can be provided for the battery cell 3; and the shell 1 is guaranteed to have a faster heat conduction rate, and the overall heat dissipation performance of the battery is improved. The problem that the first insulating layer 12 and the second insulating layer 13 are damaged in structure to cause insulation failure can be avoided, and the stability of the insulation effect is improved.

Referring to fig. 2, the connection between the side wall and the bottom wall of the metal layer 11 is provided with an arc corner 14, and correspondingly, the first insulating layer 12 and the second insulating layer 13 form a corner structure with the same shape as the arc corner 14 at the arc corner 4; the arc corresponding to the arc surface of the arc corner 14 is r, and r satisfies: pi/4 is more than or equal to r is less than or equal to 3 pi/4.

Through the arc corner 14 that sets up, realize the smooth transition between lateral wall and the diapire of metal level 11, in adopting punching press or stretch forming in-process to metal level 11, reduce the cracked risk of taking place at the junction. If the radian of the set arc corner 14 is too large (i.e. the formed arc corner 14 is too bent), the stretching amount of the raw material of the metal layer 11 at the arc corner 14 is too large, the thickness is too small, the structural strength is insufficient, and the stretching ratios of the first insulating layer 12 and the second insulating layer 13 at the corresponding positions are too large, so that the insulating layers are too thin or broken, and the risk of insulation failure is high. If the radian of the arc corner 14 is too small (i.e. the formed arc corner 14 is too gentle), the arc corner 14 occupies a larger space inside the housing 1, and is easy to interfere with the battery cell 3, so that the installation of the subsequent battery cell 3 is affected, the space utilization rate is low, and the energy density of the battery is reduced.

The radian of limiting arc turning 14 is in suitable range, avoids the too little condition of metal level 11 thickness in corresponding position, promotes casing 1's structural strength to also be difficult to appear first insulating layer 12, second insulating layer 13 and take place the fracture and lead to insulating failure's problem, promote insulating properties's stability. In addition, the situation that the arc-shaped corner 14 occupies more space inside the shell 1 is avoided, and the space utilization rate and the energy density of the battery are improved.

Referring to fig. 3, the battery cell 3 includes a positive electrode tab 31, a negative electrode tab 32, and a separator 33 disposed therebetween, wherein the positive electrode tab 31 is positioned on the front surface of the separator 33, the negative electrode tab 32 is positioned on the rear surface of the separator 33, and the negative electrode tab 33 positioned on the rear surface of the separator 33 is shown in dotted lines for convenience of illustration. For the dimensions of each part of the battery cell 3, the dimensions of the negative electrode plate 32 are shown as being larger than those of the positive electrode plate 31 in an exemplary embodiment of the present application, and of course, in actual arrangement, the dimensional relationship between the positive electrode plate and the negative electrode plate can be adjusted according to actual needs.

The separator 33 is beyond the edge outside of the positive electrode sheet 31 and the negative electrode sheet 32; the separator 33 exceeds the outer side edge of the positive electrode sheet 31 or the negative electrode sheet 32 by a dimension L, which satisfies: l is more than or equal to 1mm and less than or equal to 2mm.

For example, in the case of the wound battery cell 3, the positive electrode sheet 31, the negative electrode sheet 32, and the separator 33 are wound around an axis to form the battery cell 3, and in the case of the wound battery cell 3 having the axis being a vertical axis, the upper and lower side surfaces of the positive electrode sheet 31 and the negative electrode sheet 32 are not directly covered with the separator 33, and the tabs of the battery cell 3 are led out from the upper side surface and/or the lower side surface, and the upper side edge and the lower side edge of the separator 33 are beyond the edges of the positive electrode sheet 31 and the negative electrode sheet 32.

In combination with the shell 1 provided by the embodiment of the application, the first insulating layer 12 is arranged on the inner side of the metal layer 11, an insulating film is not required to be arranged separately, and the positive plate 31 and the negative plate 32 can be insulated from the metal layer 11 through the arranged first insulating layer 12; therefore, the size of the diaphragm 33 beyond the pole piece can be reduced, and the waste of materials is reduced on the premise of ensuring insulation between the pole piece and the metal layer 11. And, the minimum value that diaphragm 33 surpassed the pole piece size can reach the lower value than current electric core 3 structure, under the unchangeable circumstances of diaphragm 33 size, can suitably increase the size of pole piece, promotes the energy density of battery.

Illustratively, the tightness ratio between the cell 3 and the housing 1 is P, P satisfying: p is more than or equal to 98 percent. The tightness ratio defined by the application specifically refers to: for the battery cell 3 to be mounted in the housing 1 (refer to the battery cell 3 that can be directly mounted in the housing 1 without performing other processing steps), or after the battery cell 3 is taken out of the housing, the ratio of the area of the surface parallel to the opening end surface of the housing 1 on the battery cell 3 to the large area of the cover plate 2 is determined.

Through the elasticity ratio between adjustment electric core 3 and the casing 1, can avoid the extravagant problem in space, the clearance is less between electric core 3 and the inside of casing 1, and the heat that electric core 3 produced can transfer to casing 1 fast excessively, if the clearance that leaves between electric core 3 and the casing 1 inner wall is great, can seriously influence the speed of heat transfer.

In addition, in order to ensure the integral structural strength of the battery, the cover plate 2 and the metal layer 11 are welded and fixed, so that the firmness of the fixed connection of the cover plate 2 and the shell 1 can be ensured; illustratively, when the cover plate 2 is welded and fixed with the metal layer 11, the quality of the welded and fixed is better than that of the welded and fixed dissimilar metal.

In addition, the adhesive is filled between the first insulating layer 12, the second insulating layer 13 and the cover plate 2, so that the problem of partial gaps can be reduced, the overall quality of the shell 1 and the battery is improved, and the firmness of fixing the first insulating layer 12 and the second insulating layer 13 with the metal layer 11 can be improved; in particular, in the case where both the first insulating layer 12 and the second insulating layer 13 are bonded to the metal layer 11, if gaps exist between the first insulating layer 12, the second insulating layer 13 and the cover plate 2, the bonding strength between both the first insulating layer 12 and the second insulating layer 13 and the metal layer 11 is impaired.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc. are directions or positional relationships based on the operation state of the present application are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of the present application, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, unless otherwise specifically defined and limited; in addition, a plurality of the present application is referred to as two or more. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The application has been described above in connection with preferred embodiments, which are, however, exemplary only and for illustrative purposes. On this basis, the application can be subjected to various substitutions and improvements, and all fall within the protection scope of the application.

Claims

1. A battery, characterized by comprising,

A shell, wherein one side of the shell is provided with an opening;

the battery cell is arranged in the shell;

2. The battery according to claim 1, wherein a thickness d1 of the first insulating layer and a thickness d2 of the second insulating layer satisfy: d1/d2 is more than or equal to 1.1 and less than or equal to 1.5.

3. The battery according to claim 1, wherein an arc corner is arranged at the joint of the side wall and the bottom wall of the metal layer, and the arc surface of the arc corner corresponds to an arc degree r, and the arc degree r satisfies: pi/4 is more than or equal to r is less than or equal to 3 pi/4.

4. The battery of claim 2, wherein the metal layers have thicknesses d3, d1, d2, and d3 that satisfy: d3/d1 is more than or equal to 3 and less than or equal to 18, or d3/d2 is more than or equal to 3 and less than or equal to 18.

5. The battery of any one of claims 1-4, wherein the thickness d1 of the first insulating layer satisfies: d1 is more than or equal to 0.08mm and less than or equal to 0.15mm.

6. The battery according to claim 1, wherein the metal layer is made of aluminum or an aluminum alloy.

7. The battery of claim 1, wherein the cell comprises a positive electrode tab, a negative electrode tab, and a separator disposed therebetween, the separator extending beyond the edges of the positive electrode tab and the negative electrode tab;

The size of the part of the diaphragm, which exceeds the edge outer side of the positive electrode plate or the negative electrode plate, is L, and L satisfies the following conditions: l is more than or equal to 1mm and less than or equal to 2mm.

8. The battery of claim 1, wherein the tightness ratio between the cell and the housing is P, P being greater than or equal to 98%.

9. The battery of claim 1, wherein the cover plate is welded to the metal layer, and the cover plate is made of the same material as the metal layer.

10. The battery according to claim 9, wherein an adhesive is provided between the first insulating layer and the cap plate and/or between the second insulating layer and the cap plate.