Patent ID: 7807298

Claim:
A non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a separator interposed between said positive electrode and said negative electrode, and an electrolyte, wherein said positive electrode comprises a positive electrode active material comprising a particle of a composite oxide represented by a general formula: Li x Me 1-y-z M y L z O 2 , where said element Me is Ni and/or Co, said element M is at least one selected from the group consisting of Mg, Ti, and Zn, and said element L is at least one selected from the group consisting of Al, Ca, Ba, Sr, Y and Zr, said element M is uniformly distributed in said particle, and said element L is distributed more in a surface portion of said particle than an inside of said particle, said general formula satisfies 1≦x≦1.05, 0.005≦y≦0.1 and 0≦z≦0.05, said separator comprises a plurality of laminated monolayer films, said plurality of monolayer films each have a microporous structure, and a positive electrode-side monolayer film selected from said plurality of monolayer films which faces said positive electrode comprises polypropylene.