POSITIVE ELECTRODE COMPOSITION FOR LITHIUM ION SECONDARY BATTERY, POSITIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

A positive electrode composition for a lithium ion secondary battery includes an active material that can occlude and release lithium ions and a conductive material, wherein the active material is a lithium cobalt composite oxide; the conductive material is carbon black and carbon nanotubes; the carbon black has a BET specific surface area of 100 to 400 m2/g and a DBP absorption amount of 210 to 400 ml/100 g; the carbon nanotubes have an average diameter of 20 nm or less, a BET specific surface area of 170 m2/g or more, and an aspect ratio of 50 or more; and a carbon black content X (unit: % by mass) and a carbon nanotube content Y (unit: % by mass) in the positive electrode composition satisfy the following conditions (A) and (B): (A) 0.5≤(X+Y)≤2.0; (B) 0.80≤{X/(X+Y)}≤0.95.