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. Aqueous metal-redox bicatalyst batteries can incorporate value-added electro-reduction reactions, including CO2 reduction reaction, nitrogen reduction reaction, nitric oxide reduction reaction, nitrate reduction reaction, nitrite reduction reaction, hydrogen evolution reaction, and acetylene reduction reaction, during discharge process at the cathode, which is promising to achieve simultaneous electricity generation and valuable chemical production.image