Concurrent energy storage and decarbonization by metal-CO2 batteries: aqueous or non-aqueous?

Rechargeable metal-CO2 batteries (RMCBs) are highly promising for renewable energy storage and simultaneous reduction of carbon footprint from the environment, making it very attractive for next-generation battery development. An electrolyte plays a crucial role in RMCBs and determines the choice of metal anode, kinetics of reactions taking place at electrode-electrolyte interface and thus the battery performance. We comprehensively review the advances in liquid electrolytes for RMCBs, namely, non-aqueous and aqueous, to foster a clear picture of the future RMCBs and their potential applications depedning on the electrolyte system. The advantages and disadvantages of both systems and a stern comparison amongst them is also discussed. The projected battery market/economics and current status in harmony with sustainable energy storage-decarbonization for aqueous and non-aqueous RMCBs is derived followed by the overall summary and outlook. We aim to summarize the existing status and potential of aqueous and non-aqueous RMCBs along with likely improvements necessary for the real-time application of RMCBs.