Improving Electrochemical Performances of Rechargeable Li−CO2 Batteries with an Electrolyte Redox Mediator

Rechargeable Li−CO2 batteries represent a novel approach towards clean recycling and utilization of CO2. Nevertheless, there are still many obstacles to be overcome. Herein, we report the first application of an electrolyte redox mediator (LiBr) in rechargeable Li−CO2 batteries. The electrochemical performances were found to be significantly improved, especially in terms of cyclic stability and rate capability. The proposed mechanism is that LiBr is beneficial for the formation of the desired morphology of discharge products. Moreover, the electrochemically generated Br2 promotes the decomposition of Li2CO3 chemically during the charging process.