| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a high-safety vanadium secondary battery for improving battery charge/discharge efficiency without causing oxygen transfer in reaction at cathode by using a vanadium-phosphoric acid complex as an active material, and to provide a vanadium solid secondary battery having excellent energy density.SOLUTION: A cathode having, as a cathode active material, a vanadium-phosphoric acid complex whose oxidation number increases or decreases between tetravalence to pentavalence by an oxidation/reductive reaction, and an anode having, as an anode active material, a vanadium-phosphoric acid complex whose oxidation number increases or decreases between trivalence to bivalence by an oxidation/reductive reaction are arranged via a separator. Also, a configuration of a sold secondary battery without using an electrolyte can be conceived. Furthermore, a battery configuration with one kind of active material using a tetravalent vanadium-phosphoric acid complex for the cathode active material and the anode active material can be conceived. Also, water or a nonaqueous solvent or a mixture of water and the nonaqueous solvent can be used as a solvent for the electrolyte.</p> |
