CN218918998U

CN218918998U - Battery and power utilization device

Info

Publication number: CN218918998U
Application number: CN202223107260.8U
Authority: CN
Inventors: 余开明; 黄志刚; 靳玲玲
Original assignee: Zhuhai Cosmx Power Battery Co Ltd
Current assignee: Zhuhai Cosmx Power Battery Co Ltd
Priority date: 2022-11-22
Filing date: 2022-11-22
Publication date: 2023-04-25
Anticipated expiration: 2032-11-22

Abstract

The embodiment of the application provides a battery and an electricity utilization device, wherein the battery comprises a battery core and a shell wrapped outside the battery core; an explosion-proof valve is arranged on the shell, and a concave structure is arranged in a region of the battery cell, which faces the explosion-proof valve. Through setting up the explosion-proof valve on the casing, and set up the concave structure towards the region of explosion-proof valve on the electricity core to increase the space between electricity core and the explosion-proof valve, thereby improve the security performance and the cycle performance of battery.

Description

Battery and power utilization device

Technical Field

The application relates to the technical field of batteries, in particular to a battery and an electric device.

Background

The lithium ion battery has the advantages of high safety, good reliability, high energy density and the like, and is widely applied to the fields of digital products, electric automobiles, commercial vehicles, energy storage and other products. With the great popularization of new energy resources, the requirements on the energy density and the safety of the battery are higher and higher.

In order to improve the energy density and the safety performance of the whole battery pack, an explosion-proof valve can be arranged in a battery shell, the explosion-proof valve in a module is usually oriented to the ground, and under the condition that the explosion-proof valve is opened by the thermal runaway of the battery core, the thermal shock to the battery core beside the battery pack can be reduced, so that the risk of the thermal runaway of the whole battery pack is reduced. However, under the condition that the space between the battery cell and the explosion-proof valve is smaller, the pressure inside the battery cell is continuously increased due to the fact that gas cannot be discharged in time, and finally the battery cell can still possibly explode.

Disclosure of Invention

The embodiment of the application provides a battery and power consumption device to solve under the less circumstances in space between electric core and explosion-proof valve, because gaseous can not in time get rid of, lead to electric core inside pressure constantly to increase, can lead to the problem that the electric core takes place the explosion at last.

In order to solve the technical problems, the application is realized as follows:

in a first aspect, embodiments of the present application provide a battery, including a battery cell and a housing wrapped around the battery cell;

an explosion-proof valve is arranged on the shell, and a concave structure is arranged in a region of the battery cell, which faces the explosion-proof valve.

Optionally, the explosion-proof valve is located in the area where the concave structure is located in the projection area of the battery cell.

Optionally, the battery cell includes a plurality of pole pieces that the range upon range of setting, at least some pole pieces in the plurality of pole pieces towards the edge indent of explosion-proof valve to form the concave structure.

Optionally, the edge of the at least part of the pole piece is concave to a depth of less than or equal to 50mm.

Optionally, the edge of the concave structure is an arc structure.

Optionally, the arc structure comprises an arc with a radius of 1-5mm.

Optionally, the recess structure has a capacity of 0.1% -10% of the total capacity of the battery cell.

Optionally, the housing includes a plurality of sides, and the explosion-proof valve is located on any one of the plurality of sides.

Optionally, the battery further includes a first post and a second post, where the first post, the second post, and the explosion-proof valve are located on different sides of the plurality of sides, respectively, or the first post and the second post are located on a same side of the plurality of sides;

the first pole is used for being connected with the positive pole lug of the battery cell, and the second pole is used for being connected with the negative pole lug of the battery cell.

In a second aspect, embodiments of the present application provide an electrical device comprising a battery as described in the first aspect.

In this application embodiment, this battery includes electric core and the casing of parcel outside the electric core, is provided with explosion-proof valve on the casing, the orientation of electric core the region of explosion-proof valve is provided with the concave structure. Through setting up the explosion-proof valve on the casing, and set up the concave structure towards the region of explosion-proof valve on the electricity core to increase the space between electricity core and the explosion-proof valve, thereby improve the security performance of battery, in addition, the memory space of electrolyte can be increased to the concave structure of setting, is favorable to the circulation performance promotion in battery later stage.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments of the present application will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a battery according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a battery according to an embodiment of the present disclosure;

fig. 3 is another schematic structural view of a battery according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are 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 based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance. But merely to distinguish between different components. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate a relative positional relationship, which changes accordingly when the absolute position of the object to be described changes.

Referring to fig. 1, fig. 2 and fig. 3, a schematic structural diagram of a battery according to an embodiment of the present application is illustrated. The battery 100 comprises a battery cell 10 and a shell 20 wrapping the battery cell 10;

an explosion-proof valve 30 is arranged on the shell 20, and a concave structure 11 is arranged in a region of the battery cell 10 facing the explosion-proof valve 30.

It should be understood that the present application is applicable to prismatic batteries. When the pressure inside the casing 20 is smaller than the explosion value set by the explosion-proof valve 30, the gas in the casing 20 flows from the side with high pressure to the side with low pressure, the gas is discharged outwards, and when the pressure inside the casing 20 is smaller than the pressure outside the casing 20, the gas enters the inner cavity, so that the balance of the internal pressure and the external pressure is realized. When the internal pressure of the casing 20 is greater than or equal to the explosion value set by the explosion-proof valve 30, the internal pressure pushes up the internal piston body, and the gas is directly communicated with the outside through the barrier-free channel, so that the rapid gas discharge is realized, the pressure of the casing 20 is rapidly reduced, and the explosion of the battery 100 is prevented.

In this embodiment of the application, the battery 100 includes a battery cell 10 and a casing 20 wrapped outside the battery cell 10, an explosion-proof valve 30 is disposed on the casing 20, and a concave structure 11 is disposed in a region of the battery cell 10 facing the explosion-proof valve 30. By providing the explosion-proof valve 30 on the housing 20 and providing the recess structure 11 on the cell 10 toward the region of the explosion-proof valve 30, the space between the cell 10 and the explosion-proof valve 30 is increased, thereby improving the safety performance of the battery 100.

In an alternative embodiment, the explosion-proof valve 30 is located in the area where the recess 11 is located in the projection area of the battery cell 10.

It should be understood that the distance between the explosion-proof valve 30 disposed on the housing 20 and the battery cell 10 in the housing 20 is the recess depth of the recess structure 11. Under the condition that the temperature of the battery cell 10 in the casing 20 is continuously increased, the pressure in the casing 20 is continuously increased, the explosion-proof valve 30 is arranged in the projection area of the battery cell 10 and is positioned in the area where the concave structure 11 is positioned, and the gas in the casing 20 is accumulated in the concave structure 11 and is discharged to the outside through the explosion-proof valve 30, so that the pressure in the casing 20 is rapidly reduced, and the explosion of the battery 100 is prevented.

In an alternative embodiment, the battery cell 10 includes a plurality of pole pieces stacked together, and at least some of the pole pieces are recessed toward the edge of the explosion-proof valve 30 to form the recess 11.

Under the condition of ensuring the safety of the battery cell 10, the concave structure 11 is formed only by arranging part of pole pieces to concave towards the edge of the explosion-proof valve 30, so that the influence of the concave structure arranged on the battery cell 10 on the energy density loss of the battery cell 10 is reduced.

In addition, part of the pole pieces can be a plurality of pole pieces which are arranged close to the explosion-proof valve 30, the plurality of pole pieces are concaved inwards to form a concave structure 11, the concave structure 11 formed by arranging part of the pole pieces to be concaved inwards is close to the explosion-proof valve 30, the temperature of the battery cell 10 is increased, and gas in the shell 20 is accumulated in the concave structure 11, so that the generated gas can be smoothly discharged to the outside through the explosion-proof valve 30 when the battery cell 10 is out of control, the pressure in the shell 20 is rapidly reduced, and explosion of the battery 100 is prevented. The positive electrode plate and the negative electrode plate may be partially included, and it should be noted that, because the separator sandwiched between the positive electrode plate and the negative electrode plate generally has better mechanical properties and thermal stability, in this embodiment, it is not limited whether the separator is concave toward the edge of the explosion-proof valve 30.

When the method is specifically implemented, hardware die cutting can be adopted for the indent on the pole piece, and compared with a laser die cutting mode, the method has less damage to active substances on the periphery of the indent. Specifically, the length of the burr on the end surface can be 5um (the length of the burr on the section can be less than or equal to 0.5 times the thickness of the diaphragm). In addition, the production yield of the tablets with the concave pole pieces is 97.6%.

In addition, in order to ensure that the lithium precipitation phenomenon does not occur around the recess structure 11 on the battery cell 10, the concave depth of the positive electrode sheet is generally greater than the concave depth of the negative electrode, but the shape is the same, and the distance between the positive and negative electrode edges is generally controlled to be greater than 5mm and less than 11mm in consideration of the accuracy and the fluctuation of the size of the positioning of the cutting device, specifically, the distance from the edge of the negative electrode toward the explosion-proof valve side to the explosion-proof valve is 2mm to 11mm greater than the distance from the edge of the positive electrode toward the explosion-proof valve side to the explosion-proof valve. The size of the concave area is specifically set according to the specific chemical system, the capacity of the cell 10, and the volume of the generated gas during thermal runaway, and is not limited in comparison with the present embodiment. It should be noted that, the concave area is set to be smaller, that is, the concave space of the formed concave structure 11 is smaller, and when the thermal runaway occurs in the battery cell 10, the generated gas cannot be removed in time, so that the explosion of the battery 100 occurs; and a larger concave area is arranged, namely, the concave space of the formed concave structure 11 is larger, and the capacity loss of the battery cell 10 is larger.

In addition, it should be noted that, on the premise that the battery 100 provided in the present application is a square battery 100, the battery cell case provided in the present application may be a laminated battery cell structure or a wound battery cell structure, which is not limited to this embodiment.

In an alternative embodiment, the recessed features have a cell capacity of 0.1% to 10% of the total capacity of the cell.

According to calculation, the capacity of the concave structure 11/cell 10 is controlled to be between 0.1 and 10 percent, and the system can be suitable for different chemical systems and comprises systems such as lithium iron phosphate, lithium manganese iron phosphate, sodium ion battery 100, ternary nickel cobalt manganese, solid-state battery 100 and the like.

In an alternative embodiment, as shown in fig. 1, the edge of the at least part of the pole piece is recessed to a depth of 50mm or less. It should be understood that, the provision of the recess structure 11 will lose some of the capacity of the battery cell to some extent, so that when the internal pressure of the housing 20 is greater than or equal to the explosion value set by the explosion-proof valve 30, the gas can act on the explosion-proof valve through the recess surface accessible channel of 11, so as to realize rapid gas discharge, thereby rapidly reducing the pressure of the housing 20, preventing the explosion of the battery 100, and preventing the design redundancy of the recess surface as much as possible, and reducing the energy loss ratio.

In an alternative embodiment, the edges of the concave structures 11 are arc-shaped structures.

As shown in fig. 1, in order to control burrs on the concave edges of the pole pieces, four corners may be designed as R-corners, which are defined as: 1/4 of an arc, and the radius of the arc is 1-5mm.

In addition, for lithium iron phosphate systems, the required area is small, and the concave may be arranged in a semicircular shape in order to maintain the process yield, as shown in fig. 3.

In an alternative embodiment, the housing 20 includes a plurality of sides, and the explosion proof valve 30 is located on any one of the plurality of sides.

It should be appreciated that the number of sides is related to the shape of the housing 20, wherein the housing 20 may be a rectangular housing and the explosion proof valve 30 may be located on either side of the rectangular housing as shown in fig. 1, 2, and 3.

In an alternative embodiment, as shown in fig. 1, the battery 100 further includes a first post 40 and a second post 50, the housing 20 includes a plurality of sides, the explosion-proof valve 30 is located on a first side 21 of the plurality of sides, the first post 40, the second post 50, and the explosion-proof valve 30 are located on different sides of the plurality of sides, respectively, or the first post 40 and the second post 50 are located on the same side of the plurality of sides;

the first pole 40 is used for being connected with the positive pole lug of the battery cell 10, and the second pole 50 is used for being connected with the negative pole lug of the battery cell 10.

Still referring to the case 20 as a rectangular case, as shown in fig. 1, the explosion-proof valve 30 is located on the first side 21 of the case 20, and the first and

second poles

40 and 50 may be located on the second and

third sides

22 and 23 of the case 20, respectively.

In another alternative embodiment, as shown in fig. 2, the explosion proof valve 30 is located on the first side 21 of the housing 20, while the first and

second posts

40, 50 are located on the same side (the fourth side 24 of the housing 20).

In an alternative embodiment, not shown, the explosion proof valve 30, the first post 40 and the second post 50 are all located on the first side 21 of the housing 20.

In a second aspect, embodiments of the present application provide an electrical device comprising a battery 100 as described in the first aspect. Because the technical solution of the present embodiment includes all the technical solutions of the foregoing embodiments, at least all the technical effects of the foregoing embodiments can be achieved, which is not described herein in detail.

In addition, for better understanding of the embodiments of the present application, the battery in the related art and the battery provided in the embodiments of the present application are compared to make a detailed description.

Comparative example

Square batteries with the size of 256-106-24.8 (mm) are adopted, and no width space is reserved between the bare cell and the inner wall of the shell at the side with the explosion-proof valve.

Examples

Square cells of size 256 x 106 x 24.8 (mm) are used, in particular cells having a concave shapeWherein the concave area of the pole piece is 50mm ² The energy loss was about 0.5% compared to the comparative example.

By performing experimental analysis on two batteries in the comparative example and the example, the following analysis results were obtained:

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as can be seen from the above summary table, the capacity of the battery cell using this example was slightly lower than that of the battery cell of the comparative example, but after thermal runaway of the battery cell, the valve was smoothly opened inside, and accumulation and absorption of free electrolyte was achieved at the concave inner surface, and the later cycle of the battery cell, particularly the high-temperature cycle performance thereof, was significantly improved.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes or substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The battery is characterized by comprising a battery core and a shell body wrapping the battery core;

2. The battery of claim 1, wherein the explosion-proof valve is located in a region of the recessed structure in a projected region of the cell.

3. The battery of claim 1, wherein the cell comprises a plurality of pole pieces arranged in a stacked manner, at least a portion of the plurality of pole pieces having edges facing the explosion-proof valve recessed to form the recessed structure.

4. A battery according to claim 3, wherein the depth of the edge recess of the at least part of the pole piece is 50mm or less.

5. The battery of claim 1, wherein the edges of the recessed features are arcuate features.

6. The battery of claim 5, wherein the arcuate structure comprises an arc having a radius of 1-5mm.

7. The battery of claim 1, wherein the recessed features have a capacity of 0.1% to 10% of the total capacity of the cells.

8. The battery of claim 1, wherein the housing includes a plurality of sides, the explosion-proof valve being located on any one of the plurality of sides.

9. The battery of claim 8, further comprising a first post and a second post, the first post, the second post, and the explosion-proof valve being located on different sides of the plurality of sides, respectively, or the first post and the second post being located on a same side of the plurality of sides;

10. An electrical device comprising a battery as claimed in any one of claims 1 to 9.