Patent ID: 7976983

Claim:
A lithium ion secondary battery comprising a chargeable and dischargeable positive electrode, a chargeable and dischargeable negative electrode, and a non-aqueous electrolyte, the positive electrode including an active material particle, the active material particle including a reaction product of a lithium composite oxide, the lithium composite oxide being represented by the general formula (1): Li x M 1-y L y O 2 , where M is at least one selected from the group consisting of Ni and Co, and L is at least one selected from the group of alkaline earth elements, transition elements other than Ni and Co, rare earth elements, and elements of Group IIIb and Group IVb, and where 0.85≦x≦1.25 and 0≦y≦0.50; and a coupling agent having a plurality of hydrolyzable groups and at least one functional group mercapto group, alkyl group, and fluorine atom, wherein the hydrolyzable group not forming a bond with the lithium composite oxide is reacted with a ligating compound having two or more reactive groups and each of said two or more reactive groups is hydroxyl group, carbonyl group, carboxyl group, or alkoxy group.