| abstract |
In the power storage unit, tungsten oxide is used for a negative electrode layer or a positive electrode layer. Tungsten oxide has a single crystal structure of one of a monoclinic crystal, an orthorhombic crystal, and a cubic crystal. And a control circuit that controls a potential difference between the negative electrode and the positive electrode per cell of the power storage unit to a potential difference in which the type of the crystal structure of tungsten oxide serving as a main crystal is maintained in an initial state. Further, in the power storage system, the above-described power storage unit and a secondary battery are combined. |