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

The present invention provides a positive electrode composition for a lithium ion secondary battery capable of easily obtaining a lithium ion secondary battery having high energy density, low internal resistance, and excellent output characteristics, cycle characteristics, and low temperature characteristics. A positive electrode composition for a lithium ion secondary battery comprises 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/100g; 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