摘要 |
An aqueous secondary battery 10 according to the present invention includes a positive electrode containing a NASICON-type positive-electrode active material that can insert and extract sodium as a positive-electrode active material 12, a negative electrode containing a negative-electrode active material 17 that can insert and extract sodium, and an electrolyte solution 20 disposed between the positive electrode and the negative electrode, the electrolyte solution 20 being an aqueous solution in which sodium is dissolved. The NASICON-type positive-electrode active material is, for example, Na3V2(PO4)3, and the electrolyte solution 20 is an aqueous solution in which sodium is dissolved. The negative-electrode active material 17 is preferably a NASICON-type negative-electrode active material (for example, LiTi2(PO4)3 or NaTi2(PO4)3). |