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

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.