High Surface Area Tungsten Oxide as a Positive Electrode Material for Aluminum Rechargeable Batteries

WO3 with a high specific surface area of more than 100 m2 g−1 was synthesized by a simple sol-gel method to explore the potential of group VI metal oxides as the positive electrode active material for aluminum rechargeable batteries. Charge/discharge measurements indicated more than 130 mAh g−1 capacity, which is the largest WO3 electrode for an aluminum rechargeable battery. The capacity retention after 50 cycles was 80 %. From XPS measurements, the valence of tungsten changed during charging/discharging, and the content of aluminum also changed; therefore, intercalation/deintercalation type charge/discharge mechanism was confirmed for the WO3 electrode. These results indicate that WO3 with high specific surface area has high potential as a positive electrode material for aluminum rechargeable batteries.