Value-Added Aqueous Metal-Redox Bicatalyst Batteries

The development and utilization of electrochemical energy  conversion and storage devices can maximize intermittent renewable  energy and balance environmental issues. Aqueous metal-redox bicatalyst  batteries, incorporating value-added electro-reduction reactions during  discharge process at the cathode, are considered a particularly  attractive alternative for simultaneous electricity generation and  valuable chemical production. In this review, for the first time, a  holistic and subtle description of value-added metal-redox bicatalyst  batteries is made, focusing on recent efforts to optimize the energy  conversion/chemical production-involved cathodic discharging reactions,  including CO₂ reduction reaction (CO₂RR), nitrogen reduction reaction (NRR), nitric oxide reduction reaction (NORR), nitrate reduction reaction (NO₃⁻RR), nitrite reduction reaction (NO₂⁻RR),  hydrogen evolution reaction (HER), and acetylene reduction reaction  (ARR). A macroscopic understanding of design principles in terms of  anodes, cathodes, and reaction parameters is provided. Some mechanism  explorations, feasibility analyses, technoeconomic assessments, device  combinations, and associated comparisons are involved to deepen the  understanding of different systems and evaluate their application  prospects. Perspectives on and opportunities for future research  directions are also outlined.