| abstract |
A sodium secondary battery that provides a larger discharge capacity is provided. A first electrode, a second electrode, and a nonaqueous electrolyte solution, the first electrode comprising a compound represented by the following formula (I) capable of doping and dedoping sodium ions: Sodium secondary battery characterized by. M 3 Z 4 (I) (Here, M represents one or more elements selected from the group consisting of transition metal elements, and Z represents one or more elements selected from the group consisting of Group 16 elements in the IUPAC periodic table.) The sodium secondary battery as described above, wherein Z contains S. The sodium secondary battery as described above, wherein M contains Fe. The sodium secondary battery, wherein the second electrode contains sodium metal or a sodium alloy. [Selection figure] None |