| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery having excellent charge-discharge cycle performance, which includes a positive electrode containing a lithium-excess-type cathode active material.SOLUTION: A nonaqueous electrolyte secondary battery includes: a positive electrode; a nonaqueous electrolyte incorporating boric acid therein; and a negative electrode. The positive electrode includes a lithium secondary battery cathode active material containing a lithium-transition metal composite oxide represented by a composition formula LiMeO(Me is a transition metal element containing Co, Ni and Mn, 1.25≤(1+α)/(1-α)≤1.5, a mole ratio of Co in Me, Co/Me, is 0.04-0.36, and a mole ratio of Mn in Me, Mn/Me, is 0.668-0.44). |
