Recent advances in Zn–CO2 batteries for the co-production of electricity and carbonaceous fuels

Abstract

Electrochemical CO₂ reduction has been considered a promising approach to neutralizing the global CO₂ level. As an intriguing technique, metal-CO₂ battery devices can not only capture CO₂ into valuable carbonaceous chemicals and reduce the CO₂ concentration in the atmosphere but enable energy conversion. Among metal-CO₂ batteries, aqueous Zn–CO₂ batteries, especially rechargeable systems, exhibit flexible CO₂ electrochemistry in terms of multi-carbon chemicals, which are gaseous or water-soluble, in favor of rechargeability and cycling durability of aqueous battery systems. Despite the increasing number of publications on Zn–CO₂ batteries in the past three years, this field is still in its beginning stage and facing many challenges considering the capability of CO₂ fixation and battery performance. Herein, we present a timely and overall summary of the recent progress in Zn–CO₂ batteries, including fundamental mechanisms, affecting factors on electrochemical performance, catalyst cathodes, and electrolytes (catholytes and anolytes). Besides, we assess the application potential of Zn–CO₂ batteries and compare this with those of alkali metal-CO₂ batteries based on CO₂ fixation and battery performance. Finally, we point out some current challenges for the further development of Zn–CO₂ batteries and put forward perspectives of the research directions for practical applications of Zn–CO₂ batteries in the future.