Enhanced Electrochemical Performance of Aprotic Li‐CO 2 Batteries with a Ruthenium‐Complex‐Based Mobile Catalyst

Li‐CO 2 batteries are regarded as next‐generation high‐energy‐density electrochemical devices. However, the greatest challenge arises from the formation of the discharge product, Li 2 CO 3 , which would accumulate and deactivate heterogenous catalysts to cause huge polarization. Herein, Ru(bpy) 3 Cl 2 was employed as a solution‐phase catalyst for Li‐CO 2 batteries and proved to be the most effective one screened so far. Spectroscopy and electrochemical analyses elucidate that the Ru II center could interact with both CO 2 and amorphous Li 2 C 2 O 4 intermediate, thus promoting electroreduction process and delaying carbonate transformation. As a result, the charge potential is reduced to 3.86 V and over 60 discharge/charge cycles are achieved with a fixed capacity of 1000 mAh g −1 at a current density of 300 mA g −1 . Our work provides a new avenue to improve the electrochemical performance of Li‐CO 2 batteries with efficient mobile catalysts.