Correlating Catalyst Design and Discharged Product to Reduce Overpotential in Li-CO₂ Batteries

Li-CO₂ batteries with dual efficacy for greenhouse gas CO₂ sequestration and high energy output have been regarded as a promising electrochemical energy storage technology. However, battery feasibility has been hampered by inferior electrochemical performance due to large overpotentials and low cyclability primarily caused by the difficult decomposition of ultra-stable Li₂ CO₃ during charge. The use of cathode catalysts has been highlighted as a promising solution and catalyst properties, as well as the nature of discharge products, are closely correlated with electrochemical performance. Here, the catalyst design strategies that include active site enrichment, electrical transport enhancement, and mass transfer improvement are summarized. Catalyst effects on product decomposition are then subsequently introduced, while product geometry and chemical composition will be explored, with an emphasis on the formation/decomposition of Li₂ C₂ O₄ instead of Li₂ CO₃ . Building on previous research, future directions that facilitate improvements in catalyst design are put forward to reinforce the fundamental development of Li-CO₂ batteries.