Recent Advances in Rechargeable Metal-CO₂ Batteries with Nonaqueous Electrolytes

This review article discusses the recent advances in rechargeable metal-CO₂ batteries (MCBs), which include the Li, Na, K, Mg, and Al-based rechargeable CO₂ batteries, mainly with nonaqueous electrolytes. MCBs capture CO₂ during discharge by the CO₂ reduction reaction and release it during charging by the CO₂ evolution reaction. MCBs are recognized as one of the most sophisticated artificial modes for CO₂ fixation by electrical energy generation. However, extensive research and substantial developments are required before MCBs appear as reliable, sustainable, and safe energy storage systems. The rechargeable MCBs suffer from the hindrances like huge charging-discharging overpotential and poor cyclability due to the incomplete decomposition and piling of the insulating and chemically stable compounds, mainly carbonates. Efficient cathode catalysts and a suitable architectural design of the cathode catalysts are essential to address this issue. Besides, electrolytes also play a vital role in safety, ionic transportation, stable solid-electrolyte interphase formation, gas dissolution, leakage, corrosion, operational voltage window, etc. The highly electrochemically active metals like Li, Na, and K anodes severely suffer from parasitic reactions and dendrite formation. Recent research works on the aforementioned secondary MCBs have been categorically reviewed here, portraying the latest findings on the key aspects governing secondary MCB performances.