| 摘要 |
PROBLEM TO BE SOLVED: To provide an active material for nonaqueous electrolyte secondary batteries, which is large in discharge capacity, and superior in output performance in a low-SOC region.SOLUTION: An active material for nonaqueous electrolyte secondary batteries has an α-NaFeOtype crystal structure and comprises a lithium transition metal complex oxide expressed by the following compositional formula: LiMeO(where Me represents transition metal elements including Mn, Ni and Co; 0<α<1), provided that the mole ratio Co/Me of Co to Me is 0.02-0.23, and (1+α)/(1-α)≤1.425. In X-rays diffraction measurement with a CuKα tube bulb, the half-value width of a diffraction peak at 2&thetas;=18.6°±1° is 0.20°-0.27° and/or the half-value width of a diffraction peak at 2&thetas;=44.1°±1° is 0.26°-0.39°; the active material is observed as a single phase belonging to a hexagonal crystal (the space group R3-m) in an X-ray diffraction diagram when the active material is oxidized electrochemically to a potential of 5.0 V (vs. Li/Li). |
