リチウムイオン二次電池用正極材料、リチウムイオン二次電池用正極およびリチウムイオン二次電池

Japanese Patent JP6800417

B2

PROBLEM TO BE SOLVED: To provide a positive electrode material for a lithium ion secondary battery, small in gas generation amount and capable of providing a lithium ion secondary battery exhibiting a high capacity retention rate even after charge/discharge cycles.SOLUTION: In a positive electrode material for a lithium ion secondary battery, at least a part of the surface of a lithium-iron-manganese-based composite oxide is coated with at least one fluoride selected from the group consisting of MgFand KF, the lithium-iron-manganese-based composite oxide having a layered rock-salt structure and being represented by the following formula (1) LiM1MnM2FeO(1) (in the formula (1), 1.050≤x≤1.320, 0.330≤y≤0.630, 0.060≤z≤0.500, 0