abstract |
According to one embodiment, there is provided an active material. The active material contains a composite oxide represented by a following general formula:n nthe general formula: Li x (Nb 1−y Ta y ) 2−z Ti 1+0.5z M 0.5z O 7 ,n in which 0≦x≦5, 0≦y≦1, and 0<z≦1, and M is at least one metal element selected from the group consisting of Mo and W. |