Battery cover assembly, single-cell battery, battery module, power battery pack, and electric vehicle

Patent metadata

Field	Value
Publication number	US-11264663-B2
Application number	US-201816499790-A
Country	US
Kind code	B2
Filing date	Mar 16, 2018
Priority date	Mar 31, 2017
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A battery cover assembly includes a cover plate, an electrode inner terminal and an electrode outer terminal. The electrode inner terminal is electrically connected to the electrode outer terminal through a current interrupt structure disposed on the cover plate. The current interrupt structure includes a sealed chamber configured to fill a gas-producing medium therein. The sealed chamber is configured to make the gas-producing medium to be electrically connected to positive electrodes and negative electrodes of a battery. When a voltage difference between the positive electrodes and negative electrodes of the battery exceeds a rated value, the gas-producing medium is capable of producing gas, to disrupt the electrical connection between the electrode inner terminal and the electrode outer terminal under the action of the pressure of the gas.

First claim

What is claimed is:

1. A battery cover assembly, comprising a cover plate, an electrode inner terminal and an electrode outer terminal, wherein the electrode inner terminal is electrically connected to the electrode outer terminal through a current interrupt structure disposed on the cover plate, the current interrupt structure comprises a sealed chamber configured to fill a gas-producing medium therein, the sealed chamber is configured to make the gas-producing medium to be electrically connected to positive electrodes and negative electrodes of a battery, and when a voltage difference between the positive electrodes and the negative electrodes of the battery exceeds a rated value, the gas-producing medium produces gas, to disrupt the electrical connection between the electrode inner terminal and the electrode outer terminal under an action of a pressure of the gas.

2. The battery cover assembly according to claim 1 , wherein the rated value is in a range of 4.5 V to 5 V.

3. The battery cover assembly according to claim 1 , wherein the gas-producing medium comprises at least one of biphenyl, tert-amylbenzene, cyclohexylbenzene, terphenyl, cyclohexyl biphenyls or dibenzofuran.

4. The battery cover assembly according to claim 1 , wherein the battery cover assembly comprises a first polar member and a second polar member respectively in contact with the gas-producing medium, one of the first polar member and the second polar member is configured to connect to the positive electrode of the battery and the other is configured to connect to the negative electrode of the battery, the first polar member is formed by the electrode inner terminal and insulated from the cover plate, and the second polar member is connected in a sealed and insulating manner to the cover plate.

5. The battery cover assembly according to claim 4 , wherein the current interrupt structure further comprises a flipping member configured to serve as a part of a chamber wall of the sealed chamber, the electrode inner terminal and the electrode outer terminal are electrically connected to each other through the flipping member, and under the action of the pressure of the gas, the flipping member acts to disrupt the electrical connection between the electrode inner terminal and the electrode outer terminal.

6. The battery cover assembly according to claim 5 , wherein the current interrupt structure further comprises a conductive member, and the conductive member is fixed on an outer end surface of the electrode inner terminal, the flipping member is electrically connected to the conductive member, the conductive member is provided with a notch which can be broken under the action of the pressure of the gas, and the notch is disposed surrounding a connection point configured to connect to the flipping member.

7. The battery cover assembly according to claim 6 , wherein one of the flipping member and the conductive member is provided with a boss and the other one is provided with a connection hole configured to accommodate the boss, the boss being connected to the connection hole through an annular welding point.

8. The battery cover assembly according to claim 5 , wherein the electrode inner terminal is formed by a battery post extending along a medial-lateral direction, the flipping member is disposed coaxially with the battery post and radially extends outward from the battery post, and a side surface of the battery post is connected in a sealed and insulating manner to an outer periphery of the flipping member, so that the sealed chamber is formed as an annular cavity disposed around an axis of the battery post.

9. The battery cover assembly according to claim 8 , wherein an inner end portion of the battery post comprises a radial flange, an outer end surface of the radial flange is sealedly connected with an inner insulation ring, and the cover plate is sealedly connected to an outer end surface of the inner insulation ring so as to be insulated from the battery post.

10. The battery cover assembly according to claim 9 , wherein the radial flange is provided with a medium injection hole configured to communicate with the annular cavity.

11. The battery cover assembly according to claim 10 , wherein the outer end surface of the radial flange is formed as a step structure, the step structure comprises an inner ring close to the axis of the battery post and an outer ring away from the axis of the battery post, a thickness of the inner ring is greater than a thickness of the outer ring, the inner insulation ring is fixed to the outer ring, and the medium injection hole extends from an inner end surface of the radial flange to the inner ring.

12. The battery cover assembly according to claim 8 , wherein the second polar member is formed as an annular conductive sheet surrounding the annular cavity, an inner end surface of the annular conductive sheet is sealedly connected with a first outer insulation ring, the cover plate is sealedly connected to an inner end surface of the first outer insulation ring so as to be insulated from the annular conductive sheet, an outer end surface of the annular conductive sheet is sealedly connected with a second outer insulation ring, and the outer periphery of the flipping member is sealedly connected to an outer end surface of the second outer insulation ring so as to be insulated from the annular conductive sheet.

13. The battery cover assembly according to claim 12 , wherein the outer end surface of the second outer insulation ring is sealedly connected with a seal ring, the outer periphery of the flipping member is sealedly connected to the seal ring, the flipping member is further covered by a cover member, and the cover member is electrically connected to the flipping member to form the electrode outer terminal.

14. The battery cover assembly according to claim 13 , wherein the cover member is provided with a vent hole communicating with the outside.

15. A battery cell, comprising a housing and a cell accommodated in the housing, wherein the battery cell further comprises the battery cover assembly according to claim 1 , the cover plate packages the housing, and the cell is electrically connected to the electrode inner terminal.

16. A battery module, comprising the battery cell according to claim 15 disposed therein.

17. The battery cover assembly according to claim 2 , wherein the gas-producing medium comprises at least one of biphenyl, tert-amylbenzene, cyclohexylbenzene, terphenyl, cyclohexyl biphenyls or dibenzofuran.

18. The battery cover assembly according to claim 6 , wherein the electrode inner terminal is formed by a battery post extending along a medial-lateral direction, the flipping member is disposed coaxially with the battery post and radially extends outward from the battery post, and a side surface of the battery post is connected in a sealed and insulating manner to an outer periphery of the flipping member, so that the sealed chamber is formed as an annular cavity disposed around an axis of the battery post.

19. The battery cover assembly according to claim 7 , wherein the electrode inner terminal is formed by a battery post extending along a medial-lateral direction, the flipping member is disposed coaxially with the battery post and radially extends outward from the battery post, and a side surface of the battery post is connected in a sealed and insulating manner to an outer periphery of the flipping member, so that the sealed chamber is formed as an annular cavity disposed around an axis of the battery post.

Assignees

• Byd Co Ltd

Inventors

• Zheng Weixin
• Shen Xi
• Zhu Jianhua
• Jiang Luxia
• Zhu Yan

Classifications

• H01M50/35

  Gas exhaust passages comprising elongated, tortuous or labyrinth-shaped exhaust passages · CPC title

• H01M50/543

  Terminals · CPC title

• H01M50/147 Primary

  Lids or covers · CPC title

• H01M50/26

  Assemblies sealed to each other in a non-detachable manner · CPC title

• H01M50/578

  in response to pressure · CPC title