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

Abstract

Rechargeable metal–CO₂ batteries (RMCBs) are highly promising for renewable energy storage and simultaneous reduction of carbon footprint in the environment, and therefore, they are very attractive for the development of next-generation batteries. The electrolyte plays a crucial role in RMCBs and determines the choice of the metal anode, the kinetics of reactions occurring at the 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 future RMCBs and their potential applications depending on the electrolyte system. The advantages and disadvantages of both systems and a thorough comparison amongst them are also discussed. The projected battery market/economics and the current status of aqueous and non-aqueous RMCBs are derived in terms of sustainable energy storage-decarbonization, followed by an overall summary and outlook. We aim to summarize the existing status and potential of aqueous and non-aqueous RMCBs along with likely improvements necessary in electrolyte engineering for the real-time application of RMCBs.