| 摘要 |
PROBLEM TO BE SOLVED: To provide a sodium secondary battery excellent in cost performance and cycle characteristics.SOLUTION: The present invention relates to a sodium secondary battery comprising: a positive electrode containing a substance capable of inserting and detaching sodium ions; a negative electrode containing metallic sodium, a sodium-containing substance or a substance capable of inserting and detaching sodium ions; and an electrolyte having sodium ion conductivity. The substance capable of inserting and detaching sodium ions in the positive electrode contains Prussian blue (Fe[Fe(CN)]). A positive electrode material may be a Prussian blue analogue (NaFe[Fe(CN)](where, 0<x≤4.0)). The electrolyte of the present invention is an organic electrolyte or aqueous electrolyte containing sodium ions. |
