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

Abstract

Electrochemical CO 2 reduction has been considered a promising approach to neutralizing the global CO 2 level. As an intriguing technique, metal-CO 2 battery devices can not only capture CO 2 into valuable carbonaceous chemicals and reduce the CO 2 concentration in the atmosphere but enable energy conversion. Among metal-CO 2 batteries, aqueous Zn–CO 2 batteries, especially rechargeable systems, exhibit flexible CO 2 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–CO 2 batteries in the past three years, this field is still in its beginning stage and facing many challenges considering the capability of CO 2 fixation and battery performance. Herein, we present a timely and overall summary of the recent progress in Zn–CO 2 batteries, including fundamental mechanisms, affecting factors on electrochemical performance, catalyst cathodes, and electrolytes (catholytes and anolytes). Besides, we assess the application potential of Zn–CO 2 batteries and compare this with those of alkali metal-CO 2 batteries based on CO 2 fixation and battery performance. Finally, we point out some current challenges for the further development of Zn–CO 2 batteries and put forward perspectives of the research directions for practical applications of Zn–CO 2 batteries in the future.