Solar-driven efficient Li2O2 oxidation in solid-state Li-ion O-2 batteries

Although solid-state Li-O-2 battery displays the advantages of high safety and energy density as an energy storage device, the lack of success would be attributed to the unfavorable charge overpotential arisen from solid-solid interface. To address the above thorny problem, herein, a solar-driven solid-state Li-ion O-2 battery is proposed and realized, wherein the charge process is achieved via direct photo-oxidation of discharge product (Li2O2) by photoexcited holes from ZnS photocatalyst. The solar-driven charge process enables the solid-state Li-ion O-2 battery with a low charge voltage of 2.08 V and high electric energy efficiency (113%, based on output electric energy/input electric energy). These encouraging results provide an alternative way to reduce the charge overpotential of solid-state Li-O-2 batteries.