| abstract |
A high-capacity electricity storage device using abundant sodium is provided. A sodium ion-type electricity storage device having a positive electrode, a negative electrode, and an electrolyte containing sodium ions and anions, wherein the positive electrode can adsorb / desorb or dope / dedope anions. A sodium ion type electricity storage device, wherein the negative electrode can be doped / undoped with sodium ions, and is an electrode pre-doped with sodium ions. [Selection figure] None |