| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive electrode active material for a lithium secondary battery, high in capacity, long in life, low in price, and excellent in heat stability at the time of delithiuming. SOLUTION: A positive electrode active material for a lithium secondary battery is used having a composition expressed by Li1-a Ni1-b-c-d Mnb Coc Md O2 (M: an additional minor element), where -0.15<=a<=0.10, 0.02<=b<=0.45, 0<=c<=0.50, and 0<=d<=0.20, and having a calorific value (y) of 0<=y<=30% relative to Lix NiO2 at heating temperatures ranging from 175 to 300 deg.C when the quantity (x) of lithium remaining after extraction is assumed to be 0.20<=x<=0.30. In the formula, M is one or more kinds of elements selected from among the group Ia excluding hydrogen and lithium, group IIa, group IIb, group IIIb, and group IVb in the periodic table of elements, and a group comprising transition elements excluding Ni, Co, and Mn. |
