Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2017054179-A1
Application number	US-201515119050-A
Country	US
Kind code	A1
Filing date	Feb 10, 2015
Priority date	Feb 17, 2014
Publication date	Feb 23, 2017
Grant date	—

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

1 .- 4 . (canceled)

5 . 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(oxalato)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 or 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, and V is defined as a remaining space volume in the battery case and a unit of the remaining space volume is cubic centimeter.

6 . The nonaqueous electrolyte secondary battery according to claim 5 , 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.

7 . The nonaqueous electrolyte secondary battery according to claim 5 , 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.

8 . The nonaqueous electrolyte secondary battery according to claim 6 , 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.

Assignees

• Toyota Motor Co Ltd

Inventors

• Onizuka Hiroshi

Classifications

• H01M10/0525

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

• H01M4/622

  being polymers · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/366

  as layered products · CPC title