Tuning CO2 Electrocatalytic Reduction Path for High Performance of Li-CO2 Battery

The production of Li 2 CO 3 /C through CO 2 reduction reaction in nonaqueous systems is a complex four-electron, multi-step process, and the short existence time of intermediate monomers is not conducive to observation, which causes great difficulties in clarifying and regulating the CO 2 reduction path. Herein, ferrocene (Fc) as a functional additive into the electrolyte can stabilize the discharge intermediates and favor the occurrence of the two-electron reaction path during CO 2 RR, which leads to more stable operation of the Li-CO 2 battery; with the assistance of Fc, the CO 2 reduction pathway in Li-CO 2 battery is also clarified. Theoretical calculation analysis combined with experimental characterization observation confirms that Fc can shorten the CO 2 reduction distance through interaction with CO 2 and affecting the solvent environment around Li + , stabilize intermediate products to clarify the discharge path. The existence time of intermediates and discharge depth of the battery are key factors affecting the CO 2 reduction pathway. The Li 2 C 2 O 4 formed by CO 2 reduction through the 2-electron pathway is more favorable for the reversible operation of the Li-CO 2 battery than Li 2 CO 3 /C through the 4-electron pathway. This work provides inspiration for clarifying the reaction mechanism and regulating the CO 2 reduction pathway to improve the electrochemical performance of Li-CO 2 battery in the future.