Production method for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9899709-B2
Application number	US-201214370320-A
Country	US
Kind code	B2
Filing date	Jan 20, 2012
Priority date	Jan 20, 2012
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A production method for non-aqueous electrolyte secondary batteries includes a conditioning process in which an electrode group having a positive electrode and a negative electrode wound by interposing a separator therebetween is inserted inside a case a non-aqueous electrolyte including an overcharge additive is injected and the case is sealed, after which a restraining pressure is applied to the case, and charge/discharge is performed at least once. After initial charging in the conditioning process, a fracture portion is formed in secondary particles of a positive electrode active material, and then a conductive coating is formed on the fracture portion.

First claim

The invention claimed is:

1. A method for producing a non-aqueous electrolyte secondary battery, the method including: inserting an electrode group having a positive electrode and a negative electrode wound by interposing a separator therebetween into a case; injecting a non-aqueous electrolyte solution containing an overcharge additive and hermetically closing the case; and then performing a conditioning process to charge and discharge the battery at least once or more while applying restraining pressure to the case,
wherein the conditioning process includes:
subjecting the battery to an initial charge at lower restraining pressure than normal restraining pressure;
forming a fracture portion in secondary particles of a positive active material after the initial charge by performing overdischarge at a high rate and at a restraining pressure which is lower than the normal restraining pressure;
forming a conductive coating on an intrinsic surface of the fracture portion by, performing recharge at the restraining pressure lower than the normal restraining pressure and at a low rate, and raising an upper limit potential during the recharge to a decomposition potential of the overcharge additive, and
wherein the normal restraining pressure is in a range of 450 to 500 kPa, the high rate is 2C or higher, and the low rate is 1C.

2. The method for producing a non-aqueous electrolyte secondary battery according to claim 1 , wherein, after the conductive coating is formed, the restraining pressure is set to the normal restraining pressure and redischarge is performed at the low rate.

3. The method for producing a non-aqueous electrolyte secondary battery according to claim 1 , wherein the secondary particles of the positive active material has an average particle diameter of 4 μm or more.

Assignees

• Oyama Yutaka
• Okada Yukihiro
• Toyota Motor Co Ltd

Inventors

• Oyama Yutaka
• Okada Yukihiro

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title