POSITIVE-ELECTRODE MATERIAL FOR A LITHIUM ION SECONDARY BATTERY, AND MANUFACTURING METHOD THEREFOR

摘要

Provided is a positive electrode material for a safe, high-capacity, long-lived lithium ion secondary battery capable of large-current charging and discharging. Said positive electrode material contains between 5% and 30% by mass of a carbon black composite that comprises fibrous carbon and carbon black joined together and that has no more than 1.0% ash by mass in accordance with JIS K 1469. The remainder of the provided positive electrode material comprises olivine lithium iron phosphate, and volatile oxygen-containing functional groups constitute no more than 1.0% by mass of the positive electrode material. The fibrous carbon is preferably carbon nanotubes with a diameter between 5 nm and 50 nm and a specific surface area between 50 m²/g and 400 m²/g.