ELECTRONIC DEVICE

• US 20140197802A1
• Filed: 01/10/2014
• Published: 07/17/2014
• Est. Priority Date: 01/11/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei
• Granted Patent: US 9,608,463 B2
• Time in Patent Office: Days
• US Class Current: 320/137
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Degradation of a battery is prevented or the degree of the degradation is reduced, and charge and discharge performance of the battery is maximized and maintained for a long time. A reaction product, which is formed on an electrode surface and causes various malfunctions and degradation of a battery such as a lithium-ion secondary battery, is dissolved by application of electrical stimulus, specifically, by applying a signal to supply a current reverse to a current with which the reaction product is formed (reverse pulse current).

Claims

1. A method of charging an electronic device comprising:

a first electrode;

a second electrode; and

an electrolytic solution between the first electrode and the second electrode,

the method comprising;

supplying a first current that flows between the first electrode and the second electrode in a first direction during a first period; and

supplying a second current that flows between the first electrode and the second electrode in a second direction during a second period;

wherein the first direction and the second direction are opposite to each other,

wherein a reaction product grows on the first electrode by the supplying the first current, and

wherein the reaction product on the first electrode is dissolved by supplying the second current.

2. The method of charging the electronic device according to claim 1,

wherein the first period is longer than the second period.

3. The method of charging the electronic device according to claim 1,

wherein supplying the second current is repeated after the reaction product is dissolved.

4. The method of charging the electronic device according to claim 1,

wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

5. The method of charging the electronic device according to claim 1,

wherein the first electrode is a positive electrode and the second electrode is a negative electrode.

6. The method of charging the electronic device according to claim 1,

wherein the electronic device is a battery that can be charged.

7. The method of charging the electronic device according to claim 1, the electronic device further comprising a protective film that covers part of the first electrode,

wherein the reaction product that grows from a region of a surface of the first electrode that is not covered with the protective film is dissolved by supplying the second current.

8. An electronic device comprising:

a first electrode;

a second electrode; and

an electrolytic solution between the first electrode and the second electrode,

wherein a reaction product that grows on the first electrode due to a first current that flows between the first electrode and the second electrode for a first period is dissolved by supplying a second current reverse to the first current for a second period.

9. The electronic device according to claim 8,

wherein the first period is longer than the second period.

10. The electronic device according to claim 8,

wherein supplying the second current is repeated after the reaction product is dissolved.

11. The electronic device according to claim 8,

wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

12. The electronic device according to claim 8,

wherein the first electrode is a positive electrode and the second electrode is a negative electrode.

13. The electronic device according to claim 8,

wherein the electronic device is a battery that can be charged.

14. An electronic device comprising:

a first electrode;

a protective film that covers part of the first electrode;

a second electrode; and

an electrolytic solution between the first electrode and the second electrode,

wherein a reaction product that grows from a region of a surface of the first electrode that is not covered with the protective film due to a first current that flows between the first electrode and the second electrode for a first period is dissolved by supplying a second current reverse to the first current for a second period.

15. The electronic device according to claim 14,

wherein the first period is longer than the second period.

16. The electronic device according to claim 14,

wherein supplying the second current is repeated after the reaction product is dissolved.

17. The electronic device according to claim 14,

wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

18. The electronic device according to claim 14,

wherein the first electrode is a positive electrode and the second electrode is a negative electrode.

19. The electronic device according to claim 14,

wherein the electronic device is a battery that can be charged.