Non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9768446-B2
Application number	US-201314408733-A
Country	US
Kind code	B2
Filing date	Apr 30, 2013
Priority date	Jun 29, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

This invention provides a method for producing a non-aqueous electrolyte secondary battery. The method comprises constructing a battery cell that comprises a positive electrode comprising a positive electrode active material, a negative electrode comprising a negative electrode active material, and a non-aqueous electrolyte solution comprising a non-aqueous solvent and an oxalatoborate-based compound. The method further comprises charging the battery cell to form on the negative electrode a layer that is derived from the oxalatoborate-based compound and comprises boron and oxalate ions. The method further comprises carrying out a modification treatment to increase the ratio of number of moles m B of boron to number of moles m A of oxalate ions in the layer.

First claim

The invention claimed is:

1. A method for producing a non-aqueous electrolyte secondary battery, the method comprising:
constructing a battery cell that comprises a positive electrode comprising a positive electrode active material, a negative electrode comprising a negative electrode active material, and a non-aqueous electrolyte solution comprising a non-aqueous solvent, an oxalatoborate-based compound, and a difluorophosphate salt, wherein the concentration of the oxalatoborate-based compound in the non-aqueous electrolyte solution is 0,015 mol/kg to 0.05 mol/kg;
charging the battery cell to form, on the negative electrode, a layer derived from the oxalatoborate-based compound with the layer comprising boron (B) and oxalate ions; and
subjecting the battery cell to an aging treatment in which the battery cell is stored at or above a temperature of 60 ° C. in a state satisfying at least either a state of charge (SOC) not lower than 82% of a voltage not lower than 3.9 V so as to a modification treatment to increase the ratio (m B /m A ratio) of number of moles m B of boron to number of moles m A of oxalate ions in the layer to the value of 3.0 to 15.

2. The non-aqueous electrolyte secondary battery production method according to claim 1 , wherein the non-aqueous electrolyte solution used for constructing the battery cell comprises the difluorophosphate salt at a concentration of 0.05 mol/kg to 1.0 mol/kg.

3. The non-aqueous electrolyte secondary battery production method according to claim 1 , such that in the non-aqueous electrolyte solution used for constructing the battery cell, the difluorophosphate salt concentration Mc p is 1.5 times to 5 times the oxalatoborate-based compound concentration Mc B .

4. The non-aqueous electrolyte secondary battery production method according to claim 1 , wherein the positive electrode active material is a lithium transition metal oxide comprising Mn as a constituent metal.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nagai Hiroki
• Tamaki Takumi
• Onizuka Hiroshi

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/133

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

• H01M10/0525

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

• H01M4/366

  as layered products · CPC title

• H01M10/04

  Construction or manufacture in general (H01M10/058, H01M10/12, H01M10/28, H01M10/38 take precedence) · CPC title