Patent ID: 7468225

Claim:
A non-aqueous electrolyte secondary battery comprising a positive electrode capable of absorbing and desorbing lithium, a negative electrode capable of absorbing and desorbing lithium, a separator interposed between said positive electrode and said negative electrode, and a non-aqueous electrolyte, wherein said positive electrode includes a positive electrode active material represented by the general formula (1): LiM 1-x L x O 2 where x satisfies 0.005≦x≦0.1, said element M is at least one selected from the group consisting of Mn, Co and Ni, said element L is at least one selected from the group consisting of metallic elements and semi-metallic elements, and said element M and said element L are different elements, said non-aqueous electrolyte includes a phosphinate compound represented by the general formula (2): where R 1 , R 2 and R 3 are each independently an aryl group, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms or an alkynyl group having 1 to 5 carbon atoms, and wherein the content of the phosphinate compound of general formula (2) in the non-aqueous electrolyte is 0.05 to 5 parts by weight per 100 parts by weight of the non-aqueous solvent.