POSITIVE-ELECTRODE MATERIAL FOR A LITHIUM ION SECONDARY BATTERY AND MANUFACTURING METHOD OF THE SAME

摘要

Provided is a positive electrode material for a safe, high capacity, long lifetime lithium ion secondary battery capable of large current charging and discharging. The positive electrode material contains between 5% by mass or more and 30% by mass or less of a carbon black composite formed by joining together fibrous carbon and carbon black wherein ash is 1.0% or less by mass in accordance with JIS K 1469 and the remainder includes olivine-type lithium iron phosphate, and volatile oxygen-containing functional groups which constitutes 1.0% or less by mass of the positive electrode material. The fibrous carbon is preferably a nanotube having a fiber diameter of 5 nm or more and 50 nm or less and a specific surface area between 50 m2/g or more and 400 m2/g or less.