Electronic device

• US 10,044,208 B2
• Filed: 02/07/2017
• Issued: 08/07/2018
• 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
• Primary Examiner(s): Diao, M'Baye
• Application Number:
  US15/426,086
• Publication Number:
  US 20170149260A1
• Time in Patent Office: 546 Days
• Field of Search: 320137
• 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 power source;

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 from the power source that flows between the first electrode and the second electrode in a first direction during a first period; and

supplying a second current from the power source 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 supplying the first current,

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

wherein the first period is longer than the second period, and

wherein the reaction product is a compound.

2. The method of charging the electronic device according to claim 1, wherein supplying the second current is repeated after the reaction product is dissolved.

3. 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.

4. 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.

5. The method of charging the electronic device according to claim 1, wherein the electronic device is a secondary battery.

6. 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.

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

wherein the first period is longer than the second period, and

wherein the second period is longer than or equal to 10 seconds and shorter than or equal to 30 seconds.

8. An electronic device comprising:

a power source;

a first electrode;

a second electrode; and

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

wherein the first electrode is configured to cause growth of a reaction product by a first current from the power source and is configured to cause dissolution of the reaction product by a second current from the power source,

wherein the second current is a current which flows in a direction opposite to a flow direction of the first current, and

wherein the reaction product is a compound.

9. The electronic device according to claim 8, wherein the power source is configured to supply the second current more than once during one charge.

10. The electronic device according to claim 8, wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

11. The electronic device according to claim 8, wherein the first electrode is a positive electrode and the second electrode is a negative electrode.

12. The electronic device according to claim 8, wherein the electronic device comprises a secondary battery.

13. The electronic device according to claim 8, wherein the electrolytic solution is configured to deposit the reaction product on a surface of the first electrode.

14. The electronic device according to claim 8, wherein the reaction product is what is changed in quality and is degraded from part of the electrolytic solution.

15. An electronic device comprising:

a power source;

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 the first electrode is configured to cause growth of a reaction product by a first current from the power source and is configured to cause dissolution of the reaction product by a second current from the power source,

wherein the second current is a current which flows in a direction opposite to a flow direction of the first current,

wherein, by the first current, the reaction product is configured to grow from a region of a surface of the first electrode that is not covered with the protective film, and

wherein the reaction product is a compound.

16. The electronic device according to claim 15, wherein supplying the second current is repeated after the reaction product is dissolved.

17. The electronic device according to claim 15, wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

18. The electronic device according to claim 15, wherein the first electrode is a positive electrode and the second electrode is a negative electrode.

19. The electronic device according to claim 15, wherein the electronic device comprises a secondary battery.