Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10199689-B2
Application number	US-201515119050-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Feb 17, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

The present invention provides a nonaqueous electrolyte secondary battery configured such that a positive electrode, a negative electrode, and a nonaqueous electrolyte are accommodated in a battery case. The battery includes lithium bis(oxalato)borate (LiBOB) at least at the time of assembly of the battery. The negative electrode includes a film derived from the LiBOB and containing a boron atom (B) and a carbonate ion (CO 3 2− ). A ratio (mc/mb) of a molar content mc of the carbonate ion to a molar content mb of the boron atom is 4.89 or less. In a preferred aspect, when a molar content A of the LiBOB is A (mmol) and a remaining space volume in the battery case is V (cm 3 ) at the time of the assembly, a ratio A/V is 0.053 or less.

First claim

The invention claimed is:

1. A nonaqueous electrolyte secondary battery comprising:
a positive electrode;
a negative electrode;
a nonaqueous electrolyte; and
a battery case configured to accommodate the positive electrode, the negative electrode, and the nonaqueous electrolyte,
the nonaqueous electrolyte including lithium bis(oxalate)borate at least at a time of assembly of the nonaqueous electrolyte secondary battery,
the negative electrode including a film derived from the lithium bis(oxalato)borate and the film containing a boron atom and a carbonate ion,
a ratio of a molar content of the carbonate ion to a molar content of the boron atom being equal to or less than 4.89, and
a ratio of A to V being equal to more than 0.001, but less than 0.053 at the time of the assembly, where A is defined as a molar content of the lithium bis(oxalate)borate and a unit of the molar content is millimole, V is defined as a remaining space volume in the battery case and a unit of the remaining space volume is cubic centimeter, A is about 0.1 mmol to 10 mol, and V is 10 cm 3 to 90 cm 3 .

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein:
the ratio of the molar content of the carbonate ion to the molar content of the boron atom is equal to or less than 4.00.

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein:
a ratio of A to V is equal to or less than 0.020 at the time of the assembly, where A is defined as a molar content of the lithium bis(oxalate)borate and a unit of the molar content is millimole, and V is defined as a remaining space volume in the battery case and a unit of the remaining space volume is cubic centimeter.

4. The nonaqueous electrolyte secondary battery according to claim 2 , wherein:
a ratio of A to V is equal to or less than 0.020 at the time of the assembly, where A is defined as a molar content of the lithium bis(oxalate)borate and a unit of the molar content is millimole, and V is defined as a remaining space volume in the battery case and a unit of the remaining space volume is cubic centimeter.

5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein A is about 0.5 mmol to 5 mol.

Assignees

• Toyota Motor Co Ltd

Inventors

• Onizuka Hiroshi

Classifications

• H01M4/366

  as layered products · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title