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

Abstract

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 792 mAh g⁻¹ during 2 h photocharging process with a discharge potential of around 2.53 V versus Li⁺/Li. A specific capacity of 199 mAh g⁻¹, reaching the level of conventional lithium-ion batteries, can be achieved within 10 min photocharging. Moreover, the charging process of the battery can proceed under natural sunlight irradiation.