Enhanced Li2O2 Decomposition in Rechargeable Li-O2 Battery by Incorporating WO3 Nanowire Array Photocatalyst

Reducing the high charging overpotential of nonaqueous Li-O-2 batteries is very important for their energy storage ability. Herein, we propose a newly photoassisted Li-O-2 battery system, in which a WO3 nanowires array that grows on carbon textile serves as a photocatalyst on the cathode. Because of its abundant holes excited by visible light, the Li2O2 coated on WO3 nanowires can be efficiently oxidized during the charging process, resulting in the reduced charging potential and enhanced Li-O-2 battery performance. Notably, the charging potential can still maintain at 3.55 V even after 100 cycles in this photoassisted battery system, which is much lower than that of the dark state (4.4 V). These positive results indicate that the introduction of WO3 nanowires array photocatalyst provides possibilities in improving the energy conversion efficiency of the Li-O-2 battery.