Efficient CO2 utilization and sustainable energy conversion via aqueous Zn-CO2 batteries

Abstract

Looking towards the economical and efficient carbon dioxide (CO2) utilization, metal-CO2 batteries uphold a great potential to enhance the efficiency of CO2 conversion to fuels. Pertaining to this, we have fabricated B, N-containing carbon with tubular morphology (C-BN@600) derived from ionic liquid (IL) and metal-organic framework (MOF) composite as cathode catalyst with Zn foil anode for aqueous rechargeable Zn-CO2 battery. The C-BN@600 catalyst demonstrate a remarkable activity towards electrochemical CO2 reduction to methanol with a Faradaic efficiency of 74% and a Yield rate of 2665 μg h−1 mg−1cat.. The assembled battery consumes CO2 continuously and electrochemically convert it to methanol during discharge and simultaneously produces electrical energy with a remarkable energy density of 330 Wh kg−1 and a power density of 5.42 mW cm−2 which is stable for more than 12 days (>300 h, 800 cycles) at 1 mA cm−2, providing a platform to serve a dual purpose of CO2 reduction and energy storage.