CN-224232741-U - Battery cell, battery device and electricity utilization device

Abstract

The application discloses a battery cell, a battery device and an electric device, wherein the battery cell comprises a shell, an electrode assembly, a pressure relief structure and a protection piece, the electrode assembly is accommodated in the shell, the shell comprises a first wall, the pressure relief structure is arranged on the first wall, the protection piece comprises a first area and a second area which is arranged around the first area, the first area is arranged on one side of the pressure relief structure, which is away from the electrode assembly, wherein the first area is detachably connected with the second area, and the connection strength of the first area and the first wall is smaller than that of the second area and the first wall. According to the battery cell, the protection piece is arranged on one side of the first wall to prevent high-temperature and high-pressure substances discharged by other battery cells from directly splashing to the first wall to cause corrosion and penetration, so that the probability of thermal runaway chain reaction of the battery device is reduced, and when the battery cell is abnormal, the gas discharged from the pressure release structure can break through the first area to realize pressure release.

Inventors

• ZHENG SONGHAI
• LI JINGRU
• TANG DAICHUN
• LAI YOULEI
• SHI CHUNMEI
• YUAN HEHE
• LI ZHIYAO

Assignees

• 宁德时代新能源科技股份有限公司

Dates

Publication Date

20260512

Application Date

20250304

Claims (17)

1. 1. A battery cell, comprising: a housing comprising a first wall; An electrode assembly accommodated in the case; The pressure release structure is arranged on the first wall; A protector including a first region and a second region disposed around the first region, the first region being disposed on a side of the pressure relief structure facing away from the electrode assembly; Wherein the first region is detachably connected with the second region, and the connection strength of the first region and the first wall is smaller than that of the second region and the first wall.
2. 2. The battery cell of claim 1, wherein the second region is connected to the first wall and the first region is connected to the first wall through the second region.
3. 3. The battery cell of claim 2, wherein the first region has a connection strength with the second region that is less than a connection strength of the second region with the first wall.
4. 4. The battery cell of claim 3, wherein a weakened structure is provided between the first region and the second region to detachably connect the first region and the second region.
5. 5. The battery cell of claim 4, wherein the weak structure has a shape that is the same as the pressure relief structure and a geometric center that overlaps.
6. 6. The battery cell of claim 5, wherein a maximum distance between a boundary line of the weak structure and a boundary line of the relief structure on a plane parallel to the first wall is less than 3mm.
7. 7. The battery cell of claim 4, wherein the weakened structure comprises a plurality of connecting portions and a hollowed-out portion disposed between two adjacent connecting portions, the plurality of connecting portions being connected end to detachably connect the first region and the second region.
8. 8. The battery cell as recited in claim 7, wherein the hollowed-out portion has a length greater than a length of the connection portion along an extension direction of the weak structure.
9. 9. The battery cell as recited in claim 8, wherein each of the connection parts has the same length along the extending direction of the weak structure or at least two of the connection parts have different lengths along the extending direction of the weak structure.
10. 10. The battery cell of claim 2, wherein the connection between the second region and the first wall comprises at least one of an adhesive, a weld, a rivet, a fastener connection.
11. 11. The battery cell of claim 10, further comprising an electrode terminal at least partially disposed on the first wall and electrically connected to the electrode assembly, wherein the second region defines a relief aperture for the electrode terminal to pass through.
12. 12. The battery cell of claim 11, wherein the thickness of the protective member is less than the length of the electrode terminal protruding from the first wall, or the thickness of the protective member is equal to the length of the electrode terminal protruding from the first wall.
13. 13. The battery cell of claim 1, wherein the material of the guard comprises one of mica, aluminum silicate fiber, hydroxyapatite, polyimide, polyethylene.
14. 14. The battery cell according to claim 13, wherein the thickness of the protective member is 0.01mm or more and 3mm or less.
15. 15. The battery cell of claim 14, wherein the thickness of the protective member is 0.1mm or greater and 0.5mm or less.
16. 16. A battery device comprising a housing and at least one battery cell according to any one of claims 1 to 15, the battery cell being housed in the housing.
17. 17. An electrical device configured to receive electrical energy provided from the battery device of claim 16.

Description

Battery cell, battery device and electricity utilization device Technical Field The present application relates to the field of batteries, and in particular, to a battery cell, a battery device, and an electric device. Background With the continuous development of new energy technology, batteries are increasingly applied to the fields of new energy automobiles, energy storage systems and the like. Generally, the battery cell is provided with a pressure relief structure on a top cover of the housing, and the pressure relief structure can be opened and used for discharging high-temperature and high-pressure substances when the battery cell is in an abnormal state. However, the high-temperature and high-pressure substances discharged through the pressure release structure are easily splashed onto adjacent battery cells, thereby causing thermal runaway chain reaction and even causing fire or explosion. Disclosure of utility model The application provides a battery cell, a battery device and an electric device, which can protect the shell of the battery cell so as to reduce the damage of high-temperature and high-pressure substances to the shell, reduce the occurrence probability of thermal runaway chain reaction and improve the reliability and the safety of the battery device. In a first aspect, the application provides a battery cell, the battery cell comprises a shell, an electrode assembly, a pressure relief structure and a protection piece, wherein the electrode assembly is accommodated in the shell, the shell comprises a first wall, the pressure relief structure is arranged on the first wall, the protection piece comprises a first area and a second area which is arranged around the first area, the first area is arranged on one side of the pressure relief structure, which is away from the electrode assembly, wherein the first area is detachably connected with the second area, and the connection strength of the first area and the first wall is smaller than that of the second area and the first wall. According to the battery cell, the protection piece is arranged on one side of the first wall to form high-temperature-resistant protection, so that high-temperature and high-pressure substances discharged by other battery cells are prevented from directly splashing to the first wall to cause corrosion and penetration, and the probability of thermal runaway chain reaction of the battery device is reduced. The protection piece has still set up the first region that can separate with the second region in pressure release structure top, and when the battery monomer appears unusual, the gas of pressure release structure department exhaust can break through first region and realize the pressure release, reduces the inside excessive pressure of battery monomer and the probability of explosion. In some alternative embodiments, the second region is connected to the first wall, and the first region is connected to the first wall by the second region. In the above alternative embodiment, the second area is directly connected to the first wall, and the first area is indirectly connected to the first wall, so that the connection strength between the second area and the first wall is greater, and therefore, the first area can be separated from the housing before the second area, and the pressure release structure can normally realize pressure release to improve the use safety of the battery cell. In some alternative embodiments, the first region has a lower strength of connection with the second region than the second region has with the first wall. In the above-mentioned alternative embodiment, when the pressure relief structure needs to relieve pressure, the first region can be separated from the second region under the impact of the high-pressure gas, and the second region is still connected with the first wall to form a protection effect on the first wall, so as to reduce the damage of the high-temperature and high-pressure substance to the first wall. In some alternative embodiments, a weakened structure is provided between the first region and the second region to detachably connect the first region to the second region. In the above-mentioned alternative embodiment, when the pressure relief structure needs to relieve pressure, the high-pressure gas is flushed towards the protection member and directly impacts the first area, so that the weak structure with lower strength can crack in advance to separate the first area from the second area, and the first area is separated from the pressure relief structure to expose the pressure relief structure for smooth pressure relief. In some alternative embodiments, the weakening structure has the same shape as the pressure relief structure and the geometric centers overlap. In the above-mentioned alternative embodiment, after the weak structure breaks, the empty window that forms after the first region breaks away from the second region can make the pressure release structure exp