Single battery, battery pack and electric equipment

Abstract

The utility model discloses a single battery, a battery pack and electric equipment, and belongs to the technical field of batteries, the single battery comprises an anti-explosion valve, the anti-explosion valve comprises a base body and a connecting part connected to the base body in a surrounding manner; the base body is provided with a first nick and a second nick, the second nick is arranged on the side, close to the connecting part, of the first nick and communicated with the first nick, and the second nick is arranged around at least part of the periphery of the first nick; when the air pressure generated in the single battery is continuously discharged outwards, the base body explodes towards the second nick along the first nick, and the base body exploded from the middle to the periphery pierces the explosion-proof valve patch and extrudes the explosion-proof valve patch, so that the rapid discharge of the air in the battery cell is realized.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a single battery, a battery pack, and an electrical device. Background Art

[0002] Batteries usually have explosion-proof valves to release high-temperature gases in time when the battery is in thermal runaway. Generally, the thickness of the explosion-proof valve is smaller than that of the battery housing. There are also score marks on the explosion-proof valve. When the battery core is in thermal runaway, the high-pressure gas will cause the explosion-proof valve to crack at the score marks, opening the valve in time to relieve pressure, thereby preventing the battery from exploding due to high pressure.

[0003] The existing explosion-proof valve opens from the side, and there is an explosion-proof valve patch adhered to the outside of the explosion-proof valve. In the case of relatively low thermal runaway pressure, the explosion-proof valve patch will increase the resistance to lifting the explosion-proof valve, which will affect the timely discharge of the gas inside the battery core to a certain extent. Summary of the Utility Model

[0004] Object of the Utility Model: The embodiments of this application provide a single battery, aiming to overcome the technical problem that the existing explosion-proof valve opening from the side affects the timely discharge of the gas inside the battery core; another object of the embodiments of this application is to provide a battery pack; the third object of the embodiments of this application is to provide an electrical device.

[0005] Technical Solution: The single battery described in the embodiments of this application includes:

[0006] An explosion-proof valve, which includes a matrix and a connecting portion connected around the matrix;

[0007] The matrix is provided with a first score mark and a second score mark. The second score mark is arranged on the side of the first score mark close to the connecting portion and is connected to the first score mark. The second score mark surrounds at least a part of the outer circumference of the first score mark.

[0008] In some embodiments, the matrix has a geometric center I, and the minimum distance between the first score mark and the geometric center I is less than the minimum distance between the second score mark and the geometric center I.

[0009] In some embodiments, the matrix has a geometric center I, and the first score mark surrounds the geometric center I and extends in a spiral shape.

[0010] In some embodiments, the matrix is provided with a plurality of second score marks. The plurality of second score marks surround the first score mark and are spaced apart. The first score mark is connected to each second score mark.

[0011] In some embodiments, the matrix is provided with a plurality of third score marks. The plurality of third score marks are distributed on both sides of the first score mark, and each third score mark is connected to a second score mark;

[0012] The third notch is located between the second notch and the first notch communicating therewith.

[0013] In some embodiments, the explosion-proof valve includes a plurality of protruding portions, the plurality of protruding portions are connected to the base body, and are spaced apart and arranged within the first notch.

[0014] In some embodiments, the width L1 of the first notch is greater than the width L2 of the second notch.

[0015] In some embodiments, the second notch is arc-shaped.

[0016] Correspondingly, a battery pack according to an embodiment of the present application includes the above-mentioned single cell.

[0017] Correspondingly, an electrical device according to an embodiment of the present application includes the above-mentioned single cell, or includes the above-mentioned battery pack.

[0018] Beneficial effects: The single cell includes: an explosion-proof valve, and the explosion-proof valve includes a base body and a connecting portion connected around the base body; the base body is provided with a first notch and a second notch, the second notch is arranged on a side of the first notch close to the connecting portion and communicates with the first notch, and the second notch surrounds at least a part of the outer periphery of the first notch. When a relatively high air pressure is generated inside the battery cell, the thickness of the base body is relatively thick and the stiffness is relatively large, and it is not easy to deform. The first notch and the second notch belong to weak parts with the smallest stiffness, and the first notch is located inside the second notch. Compared with the second notch, the first notch is closer to the middle position of the base body, receives relatively greater pressure, and is also easier to burst; when the air pressure generated in the single cell continues to be discharged outwards, the base body will burst along the first notch towards the second notch, and the base body bursting from the middle to the periphery will pierce the explosion-proof valve patch and push it away, realizing the rapid discharge of the gas inside the battery cell and reducing the impact force on other parts above the explosion-proof valve when the gas is discharged.

[0019] The battery pack according to the embodiment of the present application includes the above-mentioned single cell, so it can have all the technical features and beneficial effects of the above-mentioned single cell.

[0020] The electrical device according to the embodiment of the present application includes the above-mentioned single cell or the above-mentioned battery pack, so it can have all the technical features and technical effects of the above-mentioned single cell or battery pack. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is an explosion schematic diagram of a single cell provided by an embodiment of the present application;

[0023] Figure 2 It is a front view of an explosion-proof valve provided by an embodiment of the present application;

[0024] Figure 3 It is a three-dimensional schematic diagram of a single cell provided by an embodiment of the present application;

[0025] Figure 4 It is a schematic diagram of the third notch of the explosion-proof valve provided by an embodiment of the present application;

[0026] Figure 5 It is a schematic diagram of the convex part of the explosion-proof valve provided by an embodiment of the present application;

[0027] Figure 6 It is a three-dimensional cross-sectional view of the explosion-proof valve provided by an embodiment of the present application;

[0028] Figure 7 For Figure 6 It is a partial enlarged structural schematic diagram of area A of the single cell in

[0029] Figure 8 It is a three-dimensional cross-sectional view of the housing provided by an embodiment of the present application.

[0030] Reference numerals: 1, housing; 11, accommodation cavity; 12, open end; 2, top cover; 21, pressure relief hole; 22, pole; 3, explosion-proof valve; 31, base; 311, first notch; 312, second notch; 3121, first arc segment; 3122, horizontal straight segment; 3123, second arc segment; 313, third notch; 314, first circular arc segment; 315, second straight segment; 316, third circular arc segment; 317, fourth straight segment; 32, connecting part; 33, convex part; 4, winding core. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0032] In the description of the present application, it should be understood that the meaning of "a plurality" is two or more, and at least one means one, two or more, unless otherwise specifically defined.

[0033] It should also be noted that in the drawings of the embodiments of the present application, the arrow marked with X represents the length direction X of the explosion-proof valve, and the arrow marked with Y represents the width direction Y of the explosion-proof valve. The introduction of the length direction X and the width direction Y is to more clearly describe the structure and relative position relationship of the components in the explosion-proof valve. In actual applications, the length direction X and the width direction Y may change according to the different placement methods of the explosion-proof valve.

[0034] The single cell includes, but is not limited to, lithium-ion single cells, primary lithium-ion batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, etc. The embodiments of the present disclosure do not limit this. The single cell can be used in mobile phones, portable devices, laptops, battery cars, electric vehicles, ships, spacecraft, electric toys, and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spaceships, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0035] In the related art, an explosion-proof valve protection patch is attached to the side of the explosion-proof valve facing away from the battery cell, and a sealed space is formed between the explosion-proof valve and the explosion-proof valve protection patch, thereby preventing the residual electrolyte on the top cover from flowing into the upper surface of the explosion-proof sheet during liquid injection, and at the same time preventing foreign objects from piercing the explosion-proof sheet.

[0036] The single cell in the embodiments of the present application can be a square shell battery or a cylindrical battery.

[0037] Please also refer to Figure 1 and Figure 8 , the single cell of the embodiments of the present application includes: a housing 1, a wound core 4, a top cover 2, and an explosion-proof valve 3. The housing 1 has a receiving cavity 11 and an opening 12 communicating with the receiving cavity 11; the wound core 4 is formed by laminating or winding electrode sheets and separators, and the wound core 4 is accommodated in the receiving cavity 11; the top cover 2 is connected to the housing 1 and seals the opening 12, closing the opening 12; two electrode posts 22 are provided on the top cover 2, one end of each electrode post 22 is connected to the wound core 4, and the other end is used for connecting to an external circuit.

[0038] A pressure relief hole 21 communicating with the receiving cavity 11 is provided on the top cover 2, and the explosion-proof valve 3 seals the pressure relief hole 21. When the air pressure generated inside the battery cell exceeds the preset pressure, the explosion-proof valve 3 breaks open, and the gas inside the battery cell is discharged from the pressure relief hole 21 to achieve pressure relief.

[0039] Please also combine with Figure 1 and Figure 2 , the explosion-proof valve 3 includes a base body 31 and a connecting portion 32 connected around the base body 31. The connecting portion 32 is connected to one side of the top cover 2 facing the winding core 4 and is arranged around the pressure relief hole 21 to form an annular structure. The connecting portion 32 blocks at least part of the pressure relief hole 21, and the connecting portion 32 and the base body 31 jointly seal the pressure relief hole 21. In some embodiments, one end of the connecting portion 32 away from the base body 31 is connected to the top cover 2.

[0040] The base body 31 is provided with a first notch 311 and a second notch 312. The second notch 312 is arranged on one side of the first notch 311 close to the connecting portion 32 and communicates with the first notch 311. The second notch 312 surrounds at least part of the outer periphery of the first notch 311.

[0041] The first notch 311 and the second notch 312 are structures recessed in the direction of the winding core 4, that is, the openings of the first notch 311 and the second notch 312 are arranged on the surface of the base body 31 facing away from the winding core 4. Both the first notch 311 and the second notch 312 are recessed from the surface of the base body 31 facing away from the winding core 4 towards the surface of the base body 31 facing the winding core 4. Therefore, the first notch 311 and the second notch 312 constitute a weak part of the base body 31, that is, the stiffness of the first notch 311 and the second notch 312 is less than the stiffness of the rest of the base body 31. The first notch 311 is located inside the second notch 312, so that the first notch 311 is closer to the middle position of the base body 31. When subjected to gas pressure, the first notch 311 is subjected to greater pressure than the second notch 312, so it is easier to burst, realizing a breakthrough from the middle position of the base body 31.

[0042] When the air pressure generated inside the battery cell exceeds the preset pressure, the first notch 311 and the second notch 312 break, causing the base body 31 to burst from the middle to the periphery along the first notch 311 and the second notch 312. The burst base body 31 will pierce the explosion-proof valve patch and push the explosion-proof valve patch away, so that the pressure relief hole 21 is opened to exhaust and relieve pressure, realizing the rapid discharge of the pressure gas and avoiding the explosion of the battery.

[0043] Compared with the form of opening the valve on the side, that is, when opening the valve, the whole explosion-proof valve is lifted from one side to the other side, the structural design of piercing the explosion-proof valve patch from the middle will make the acting force on the explosion-proof valve patch concentrated to quickly push open the explosion-proof valve patch.

[0044] Please refer to Figure 2 , in some embodiments, the base body 31 has a geometric center I, and the minimum distance between the first notch 311 and the geometric center I is less than the minimum distance between the second notch 312 and the geometric center I.

[0045] By comparing the minimum distance between the first notch 311 and the geometric center I with the minimum distance between the second notch 312 and the geometric center I, the relative positions of the first notch 311 and the second notch 312 are further defined, and the first notch 311 is closer to the geometric center I than the second notch 312.

[0046] The geometric center describes the most central position of an object with a certain symmetry. These objects may include circles, spheres, parallelograms, etc. For example, in a circle, the geometric center is the center of the circle; in a sphere, the geometric center is the center of the sphere; in a parallelogram, the geometric center usually refers to the intersection of the two diagonals. In the embodiments of the present application, the geometric center I may be the center of the base 31 or the center of the surface of the base 31 facing away from the core 4.

[0047] Please also refer to Figure 2 and Figure 3 , the base 31 includes a first arc segment 314, a second straight segment 315, a third arc segment 316, and a fourth straight segment 317 connected end to end. The first arc segment 314 and the third arc segment 316 are spaced apart along the length direction of the explosion-proof valve 3, and the second straight segment 315 and the fourth straight segment 317 are arranged along the width direction of the explosion-proof valve 3 and both extend along the length direction of the explosion-proof valve 3. The inner diameters of the first arc segment 314 and the third arc segment 316 are equal, and the lengths of the second straight segment 315 and the fourth straight segment 317 are equal. The midpoint of the connection line between the centers of the first arc segment 314 and the third arc segment 316 is the geometric center of the base 31, marked as I in the drawings.

[0048] The minimum distance between the first notch 311 and the geometric center I is less than the minimum distance between the second notch 312 and the geometric center I. That is to say, the first notch 311 is closer to the geometric center I than the second notch 312, or the first notch 311 is located at the position of the geometric center I. On this basis, on the one hand, it can ensure that the base 31 can be lifted from its middle position through the first notch 311, and on the other hand, it can be more easily broken along the notch when the explosion-proof valve 3 is subjected to uniform pressure, so as to more reliably achieve the explosion-proof function.

[0049] Please refer to Figure 2 , in some embodiments, the first notch 311 surrounds the geometric center I and extends spirally from the inside to the outside.

[0050] The spiral direction of the first notch 311 can be clockwise or counterclockwise, which is not limited here. The spiral-shaped first notch 311 can distribute the pressure more evenly, so that when the explosion-proof valve 3 needs to be opened, the first notch 311 can be more evenly stressed, ensuring that the explosion-proof valve 3 can be stably opened under the set pressure.

[0051] In the above embodiments, the second notch 312 has a first arc segment 3121, a straight segment 3122, and a second arc segment 3123 that are connected to each other. The straight segment 3122 is connected between the first arc segment 3121 and the second arc segment 3123. The straight segment 3122 extends along the length direction of the explosion-proof valve 3. The first notch 311 is connected to the straight segment 3122.

[0052] In some other embodiments, the spiral first notch 311 can also be referred to as a shape like a mountain road, a vortex shape, etc.

[0053] Please also combine Figure 3 and Figure 4 , in some embodiments, the base body 31 is provided with a plurality of second notches 312. The plurality of second notches 312 are arranged around the first notch 311 and are spaced apart. The first notch 311 communicates with each second notch 312.

[0054] Compared with a single notch shape, such as a straight notch, the first notch 311 and the plurality of second notches 312 form a relatively complex rupture path, so that when the explosion-proof valve 3 reaches a predetermined pressure, the base body 31 can quickly rupture along the first notch 311 and the second notch 312, thereby quickly releasing the internal pressure and reducing the explosion risk. Compared with a single notch, the rupture area of the first notch 311 and the plurality of second notches 312 is larger, which can better meet the requirement of quickly releasing pressure and improve the explosion-proof effect.

[0055] Please also combine Figure 3 and Figure 4 , in some embodiments, the base body 31 is provided with a plurality of third notches 313. The plurality of third notches 313 are distributed on both sides of the first notch 311. Each third notch 313 communicates with a second notch 312. The third notch 313 is located between the second notch 312 and the first notch 311 that it communicates with. The third notch 313 extends the path of the second notch 312, increasing the area when the base body 31 explodes, which is beneficial to accelerating the gas discharge speed inside the single battery.

[0056] In the above embodiments, the first notch 311 and the third notch 313 both extend along the width direction of the explosion-proof valve 3. The first notch 311 is located at the geometric center I. There are two second notches 312 and two third notches 313. The two third notches 313 are symmetrically distributed with respect to the first notch 311. The first notch 311, the second notch 312, and the third notch 313 form a centrosymmetric figure with respect to the geometric center I. After the first notch 311, the second notch 312, and the third notch 313 form a centrosymmetric figure, stress concentration can be reduced. When the explosion-proof valve 3 is in a pressure environment, stress will concentrate around the notch. Through the first notch 311, the second notch 312, and the third notch 313, the stress can be relatively evenly dispersed over the entire surface of the substrate 31, reducing the damage that may be caused by stress concentration.

[0057] Please also combine Figure 5 , Figure 6 and Figure 7 , in some embodiments, the explosion-proof valve 3 includes a plurality of protrusions 33. The plurality of protrusions 33 are connected to the substrate 31 and are spaced apart within the first notch 311. The width L1 of the first notch 311 is greater than the width L2 of the second notch 312.

[0058] The plurality of protrusions 33 play a role in increasing the strength of the first notch 311, enabling the first notch 311 to withstand a higher predetermined pressure. Through the cooperation of the width setting of the first notch 311 and the protrusions 33, the strength at the position of the first notch 311 is balanced, enabling the explosion-proof valve 3 to meet the requirements of different application scenarios.

[0059] The width L1 of the first notch 311 is the distance between the opposite inner walls of the first notch 311 in the width direction of the explosion-proof valve 3. The width L2 of the second notch 312 is the distance between the opposite inner walls of the first notch 311 in the width direction of the explosion-proof valve 3.

[0060] In the above embodiments, the number of the second notches 312 is two and they are arc-shaped. The first notch 311 extends along the length direction of the explosion-proof valve 3. The first notch 311 is located at the geometric center I. It can also be said that the midpoint of the first notch 311 in length is located at the geometric center I. The two second notches 312 are connected to both ends of the first notch 311 and are relatively distributed with respect to the first notch 311.

[0061] The arc-shaped second notches 312 play a role in smoothing the shape of the notch, enabling the stress to be evenly distributed. Compared with a straight notch, the arc-shaped second notches 312 can adapt to the curved surface shape of the explosion-proof valve surface, increasing the geometric matching degree between them and facilitating the improvement of mechanical stability.

[0062] Correspondingly, a battery provided by an embodiment of the present application includes the single battery of the above embodiment. Therefore, the battery pack can have all the technical features and beneficial effects of the above single battery, which will not be elaborated herein.

[0063] Correspondingly, an electrical device provided by an embodiment of the present application can be various types of devices such as new energy vehicles, computers, energy storage power supply devices, etc. It can be understood that the electrical device includes the single battery of the above embodiment, or includes the battery pack of the above embodiment, and thus can have all the technical features and technical effects of the above single battery or battery pack, which will not be elaborated herein.

[0064] The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application. Those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: An explosion-proof valve (3), the explosion-proof valve (3) comprising a base (31) and a connecting portion (32) surrounding and connected to the base (31); The base (31) is provided with a first notch (311) and a second notch (312); the second notch (312) is arranged on a side of the first notch (311) close to the connecting portion (32) and is connected to the first notch (311); the second notch (312) is arranged around at least a portion of the periphery of the first notch (311).

2. The single cell according to claim 1, characterized in that: The substrate (31) has a geometric center I, and the minimum distance between the first notch (311) and the geometric center I is smaller than the minimum distance between the second notch (312) and the geometric center I.

3. The single cell according to claim 1, characterized in that: The base (31) has a geometric center I, and the first notch (311) surrounds the geometric center I and extends from the inside to the outside in a spiral shape.

4. The single cell according to claim 1 or 2, characterized in that: The base (31) is provided with a plurality of second notches (312), the plurality of second notches (312) are arranged around the first notch (311) and are distributed at intervals, and the first notch (311) is connected to each of the second notches (312).

5. The single cell according to claim 4, characterized in that: The base (31) is provided with a plurality of third notches (313), the plurality of third notches (313) are distributed on both sides of the first notch (311), and each of the third notches (313) is connected to one of the second notches (312); The third notch (313) is located between the second notch (312) and the first notch (311) which are connected thereto.

6. The single cell according to claim 4, characterized in that: The explosion-proof valve (3) comprises a plurality of protrusions (33), wherein the plurality of protrusions (33) are connected to the base body (31) and are arranged at intervals in the first notch (311).

7. The single cell according to claim 6, characterized in that: A width L1 of the first notch (311) is greater than a width L2 of the second notch (312).

8. The single cell according to claim 6, characterized in that: The second notch (312) is arc-shaped.

9. A battery pack, characterized in that: A single cell comprising the single cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: A single cell comprising any one of claims 1 to 8, or a battery pack comprising claim 9.

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