Electrochemical cell

• US 20060035143A1
• Filed: 07/20/2005
• Published: 02/16/2006
• Est. Priority Date: 08/10/2004
• Status: Active Grant

• Current Assignee: Seiko Instruments Incorporated (Seiko Group)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Kida, Tomohiko, Tahara, Kensuke, Onodera, Hideharu, Watanabe, Shunji, Nakamura, Yoshibumi
• Granted Patent: US 7,883,796 B2
• Time in Patent Office: Days
• US Class Current: 429/185
• CPC Class Codes: H01G 11/04 Hybrid capacitors
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/058 Construction or manufacture
• CPC Class Codes: H01M 50/169 by welding, brazing or soldering
• CPC Class Codes: H01M 50/184 characterised by their shape or structure
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• CPC Class Codes: H01M 50/191 Inorganic material
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/4911 including sealing
• CPC Class Codes: Y10T 29/49114 including adhesively bonding

Abstract

In a conventional electrochemical cell, since a welding between a container and a sealing plate is performed in the atmospheric air, a weld zone is oxidized and a corrosion resistance decreases. For this reason, impurities are eluted from the weld zone into an electrolyte, and this causes an internal resistance increase and a capacity decrease of the electrochemical cell. Further, there is a possibility that an organic solvent in the electrolyte is oxidized by the welding. According to the invention, in order to solve the above problems, the seal welding between the container and the sealing plate of the electrochemical cell is performed under an inert atmosphere.

Claims

1. An electrochemical cell comprising one pair of electrodes acting as a positive electrode and a negative electrode, a separator for separating the electrodes, an electrolyte, a container accommodating the electrodes, the separator and the electrolyte, and a sealing plate welded to the container under an inert atmosphere.

2. An electrochemical cell according to claim 1, wherein the inert atmosphere is nitrogen or argon.

3. An electrochemical cell according to claim 1, wherein the sealing plate welded to the container by a resistance seam welding or a laser seam welding.

4. An electrochemical cell according to claim 1, wherein the container comprises a heat-resistant material.

5. An electrochemical cell according to claim 1, wherein the container uses any of a ceramic or a glass, and a metal ring is disposed in the container contacting with the sealing plate.

6. An electrochemical cell according to claim 1, wherein the container uses a resin, and a metal ring is disposed in a portion contacting with the sealing plate.

7. An electrochemical cell according to claim 1, wherein the container uses an epoxy resin, and a metal ring is disposed in a portion contacting with the sealing plate.

8. An electrochemical cell according to claim 1, wherein the sealing plate welded to the container under a pressurized inert atmosphere.

9. An electrochemical cell according to claim 1, wherein a dew point in the inert atmosphere is 0 degree or lower.

10. A method of manufacturing an electrochemical cell, comprising a 1st process of incorporating at least one pair of electrodes and a separator into a container, a 2nd process of injecting an electrolyte into the container, a 3rd process of mounting a sealing plate onto the container, and a 4th process of welding and sealing the container and the sealing plate, wherein the 4th process is performed under an inert atmosphere.

13. A method of manufacturing an electrochemical cell according to claim 10, wherein the 4th process is performed under a nitrogen atmosphere or an argon atmosphere.

14. A method of manufacturing an electrochemical cell according to claim 10, wherein the 4th process is performed by a resistance seam welding or a laser seam welding.

15. A method of manufacturing an electrochemical cell according to claim 10, wherein the 4th process is performed under a pressurized inert atmosphere.

16. A method of manufacturing an electrochemical cell according to claim 10, wherein a heat-resisting material is used in the container.

17. A method of manufacturing an electrochemical cell according to claim 10, wherein the container uses any of a ceramic or a glass and, in the container, a metal ring is joined to a portion contacting with the sealing plate.

18. A method of manufacturing an electrochemical cell according to claim 10, wherein the container uses a resin and, in the container, a metal ring is joined to a portion contacting with the sealing plate.

19. A method of manufacturing an electrochemical cell according to claim 10, wherein the container uses an epoxy resin and, in the container, a metal ring is joined to a portion contacting with the sealing plate.

20. A method of manufacturing an electrochemical cell according to claim 10, wherein a dew point of the inert atmosphere in the 4th process is 0 degree or lower.

11. A method of manufacturing an electrochemical cell, comprising a 1st process of joining a 1st electrode to a bottom part of a container and disposing a separator onto the electrode, a 2nd process of injecting an electrolyte into the container, a 3rd process of joining a 2nd electrode to a sealing plate, and a 4th process of welding and sealing the container and the sealing plate, wherein the 4th process is performed under an inert atmosphere.

12. A method of manufacturing an electrochemical cell, comprising a 1st process of joining a positive electrode to a bottom part of a container and disposing a separator onto the electrode, a 2nd process of injecting an electrolyte into the container, a 3rd process of joining a negative electrode to a sealing plate, and a 4th process of welding and sealing the container and the sealing plate, wherein the 4th process is performed under an inert atmosphere.