Non-aqueous electrolyte secondary battery and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9755238-B2
Application number	US-201214359433-A
Country	US
Kind code	B2
Filing date	Sep 10, 2012
Priority date	Nov 22, 2011
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A non-aqueous electrolyte secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte solution. The negative electrode includes a coating derived from lithium bis(oxalate)borate. The coating derived from lithium bis(oxalate)borate includes a coating containing boron element and a coating containing oxalate ion. A ratio of the boron element contained in the coating derived from lithium bis(oxalate)borate to the oxalate ion is equal to or more than 5. Accordingly, it is possible to provide a non-aqueous electrolyte secondary battery capable of reliably obtaining the effect due to the formation of a coating.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery, comprising:
a positive electrode;
a negative electrode; and
a non-aqueous electrolyte solution, wherein
the negative electrode includes a coating,
the coating contains
a compound containing boron element, the compound being represented by the following formula:

 and
an oxalate ion, and

a ratio of the boron element to the oxalate ion is equal to or more than 5.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the ratio of the boron element to the oxalate ion is equal to or more than 5.9.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the ratio of the boron element to the oxalate ion is equal to or more than 7.1.

4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the ratio of the boron element to the oxalate ion is equal to or more than 10.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the ratio of the boron element to the oxalate ion is equal to or more than 13.4.

6. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the non-aqueous electrolyte solution contains lithium difluorophosphate.

7. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the compound containing boron element and the oxalate ion contained in the coating are products of a reductive decomposition of a lithium bis(oxalate)borate.

8. A method of manufacturing a non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a non-aqueous electrolyte solution, the method comprising:
adding lithium bis(oxalate)borate to the non-aqueous electrolyte solution; and
performing a conditioning process for charging and discharging the non-aqueous electrolyte secondary battery to form a coating containing a compound containing boron element and oxalate ion, wherein the compound containing boron element and oxalate ion are products of the reductive decomposition of the lithium bis(oxalate)borate on the negative electrode, a ratio of boron element contained in the coating to oxalate ion contained in the coating being set to 5 or more, wherein the compound is represented by the following formula:

9. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 8 , wherein
the conditioning process includes a process of repeating a process of charging the non-aqueous electrolyte secondary battery to a first state of charge and thereafter discharging the non-aqueous electrolyte secondary battery to a second state of charge, and
a range between the first state of charge and the second state of charge is equal to or more than 20% and equal to or less than 50%.

10. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 9 , wherein the range between the first state of charge and the second state of charge is equal to or more than 30% and equal to or less than 50%.

11. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 9 , wherein the range between the first state of charge and the second state of charge is 40%.

12. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 8 , wherein lithium bis(oxalate)borate is added to the non-aqueous electrolyte solution with a concentration of lithium bis(oxalate)borate of 0.1 mol/kg or less in the non-aqueous electrolyte solution.

13. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 8 , wherein lithium bis(oxalate)borate is added to the non-aqueous electrolyte solution with a concentration of lithium bis(oxalate)borate of 0.025 mol/kg or less in the non-aqueous electrolyte solution.

14. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 8 , wherein the non-aqueous electrolyte solution contains lithium difluorophosphate.

Assignees

• Onizuka Hiroshi
• Nakano Tomohiro
• Kikuchi Kyoko
• Toyota Motor Co Ltd

Inventors

• Onizuka Hiroshi
• Nakano Tomohiro
• Kikuchi Kyoko

Classifications

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/0447 Primary

  of complete cells or cells stacks · CPC title

• H01M2300/0017

  Non-aqueous electrolytes · CPC title