Patent ID: 7455933

Claim:
A nonaqueous electrolyte secondary battery comprising a negative electrode, a nonaqueous electrolyte, and a positive electrode containing an active material containing lithium composite oxide particles; wherein the lithium composite oxide particles have a composition containing element M including Ni and/or Co, include secondary particles, and exhibit a peak intensity ratio that satisfies the following formula (1), a content of the lithium composite oxide particles in the active material is at least 50 wt %; the active material satisfies the following formula (2), and has a particle distribution wherein a particle diameter at a volumetric cumulative frequency of 90% (D90) falls within the range of 10 to 25 μm; and the nonaqueous electrolyte contains a sultone compound including a ring having at least one double bond; 2.4≦( I 003 /I 104 )<5 (1) 0.95≦( Y Li /Y M )≦1.02 (2) wherein I 003 is a peak intensity (cps) at (003) plane in powder X-ray diffraction of the lithium composite oxide particles; I 104 is a peak intensity (cps) at (104) plane in said powder X-ray diffraction; Y Li is the number of moles of lithium in the active material; and Y M is the number of moles of the element M in the active material.