| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with a positive electrode including a Mn-rich lithium transition metal complex oxide as a positive electrode active material, which has an increased capacity density per unit mass and an adequate charge/discharge cycle performance.SOLUTION: A nonaqueous electrolyte secondary battery comprises: a positive electrode including, as a positive electrode active material, a lithium transition metal complex oxide having an α-NaFeOstructure, and arranged so that the mole ratio Mn/Me of Mn in the transition metal is given by Mn/Me>0.5; and a negative electrode including, as a negative electrode active material, a carbonaceous material and a substance including Si as a constituent element, in which a Si quantity in the substance including Si as a constituent element accounts for x%(0<x≤1.9) of the negative electrode active material in mass ratio. Thus, a nonaqueous electrolyte secondary battery high in capacity density per unit mass and superior in charge/discharge cycle performance is provided by a combination of the positive and negative electrodes.SELECTED DRAWING: Figure 2 |
