Additive for positive electrode material for lithium secondary battery, positive electrode material for lithium secondary battery, and positive electrode and lithium secondary battery using the positive electrode material for lithium secondary battery

摘要

An object of the invention is to obtain such a lithium secondary battery that has high safety and is small in increase of the resistance in a full charged state. Means for solution of the invention relates to a positive electrode material for a lithium secondary battery containing a positive electrode active substance and a fullerene compound, characterized in that the fullerene compound is present on a surface of the positive electrode active substance; improvement of a lithium secondary battery in safety by making a fullerene compound present on a surface of a positive electrode active substance to suppress electrolysis of an electrolyte solution on a surface of a positive electrode particularly upon float charging; and suppression of increase of the resistance upon storing in a full charged state by making a fullerene compound present on a surface of a positive electrode active substance.