Integrating a Photocatalyst into a Hybrid Lithium-Sulfur Battery for Direct Storage of Solar Energy

Direct capture and storage of abundant but intermittent solar energy in electrical energy-storage devices such as rechargeable lithium batteries is of great importance, and could provide a promising solution to the challenges of energy shortage and environment pollution. Here we report a new prototype of a solar-driven chargeable lithium-sulfur (Li-S) battery, in which the capture and storage of solar energy was realized by oxidizing S2- ions to polysulfide ions in aqueous solution with a Pt-modified CdS photocatalyst. The battery can deliver a specific capacity of 792mAhg(-1) during 2h photocharging process with a discharge potential of around 2.53V versus Li+/Li. A specific capacity of 199mAhg(-1), reaching the level of conventional lithium-ion batteries, can be achieved within 10min photocharging. Moreover, the charging process of the battery can proceed under natural sunlight irradiation.