Advancements in metal-CO2battery technology: A comprehensive overview

Rechargeable metal-CO2batteries have drawn significant research interest for their potential in effective CO2reduction, value-added CO2conversion, and high-performance energy storage, vital for upgrading our energy structure. However, challenges like high charge overpotential, poor electrochemical reversibility, and low-rate capabilities hinder their application, stemming from unique deposition and decomposition features and slow kinetics of CO2RR and CO2ER at the electrode-electrolyte-CO2interface. The complex nature of metal-CO2battery systems has sparked debates and ambiguities in the mechanistic pathways of CO2RR and CO2ER, underscoring the need for continued research to drive efficient and reliable metal-CO2batteries. To advance the field and bridge knowledge gaps, conducting comprehensive reviews covering various metal-CO2battery chemistries is essential. This review delves into the mechanistic understanding of electrochemical reactions in metal-CO2batteries, considering various chemistries, catalysts, and electrolytes. This review covers most reported metal anodes, including Li, Na, K, Al, Zn, and Mg, and emphasizes state-of-the-art characterization technologies and computational modeling methods to unveil the underlying principles that governs the complex multi-phase redox reactions in metal-CO2systems. This review aims to inspire new ideas and explorations to overcome fundamental challenges and facilitate the future development of metal-CO2batteries, exploring their potential applications for practicalization.