abstract |
Provided is a lithium-manganese-type solid solution positive electrode material capable of effectively suppressing gas generation in an initial cycle. Proposed is a lithium-manganese-type solid solution positive electrode material that includes a monoclinic structure of C2/m in a hexagonal structure of a space group R-3m. The lithium-manganese-type solid solution positive electrode material contains a solid solution expressed by a composition formula: xLi 4/3 Mn 2/3 O 2 +(1−x)LiMn α Co β Ni γ O 2 (in the formula, 0.2≦α≦0.6, 0≦β≦0.4, and 0.2≦γ≦0.6). In the composition formula, x is equal to or more than 0.36 and less than 0.50. |