China's new solar battery converts sunlight into stored electricity

Chinese researchers at Nanjing Tech University have developed a novel solar redox flow battery (SRFB) that integrates sunlight harvesting and energy storage within a single electrochemical system, achieving a solar-to-electricity conversion efficiency of 4.2% under simulated sunlight. Unlike conventional solar setups that use separate photovoltaic panels and batteries, this SRFB directly triggers chemical reactions in a circulating electrolyte to store energy without first converting it into grid electricity. The battery employs anthraquinone-based redox couples (2,6-DBEAQ and K4[Fe(CN)6]) paired with a triple-junction amorphous-silicon photoelectrode, enhancing chemical compatibility and addressing issues of photoelectrode corrosion and redox couple instability seen in prior designs. The SRFB's photocathode was made from commercial triple-junction amorphous-silicon photovoltaic cells, electrically connected to a carbon-felt counter electrode, with two liquid electrolytes circulating continuously and separated by a Nafion ion