High-Performance Solar Redox Flow Battery toward Efficient Overall Splitting of Hydrogen Sulfide

Solar redox flow batteries (SRFBs) integrate solar energy conversion devices and redox flow batteries (RFBs) to realize the flexible storage/utilization of solar energy by charging/discharging redox species, and electricity is the output of a SRFB. As a beneficial supplement, the charged redox species could be also used as the energy carrier to drive chemical reactions. Herein, targeting an important H2S splitting reaction, a new SRFB based on H-4[(SiW12O40)-O-VI]/H-6[(SiW10W2O40)-W-VI-O-V] and Fe2+/Fe3+ redox species and perovskite solar cells is typically designed and constructed. A solar-to-chemical energy conversion efficiency of more than 15.2% is achieved during the charging step. The chemical energy stored in redox species is subsequently discharged to realize H-2 and sulfur production on nonprecious catalysts. A net solar energy conversion efficiency of 2.9% is obtained in the whole cycle. This work illustrates the importance of a rational process and material engineering toward cost-effective and flexible chemical conversion via SRFBs.