Enhanced Electrochemical Performance of Aprotic Li-CO Batteries with a Ruthenium-Complex-Based Mobile Catalyst.

Li-CO batteries are regarded as next-generation high-energy-density electrochemical devices. However, the greatest challenge arises from the formation of the discharge product, Li CO , which would accumulate and deactivate heterogenous catalysts to cause huge polarization. Herein, Ru(bpy) Cl was employed as a solution-phase catalyst for Li-CO batteries and proved to be the most effective one screened so far. Spectroscopy and electrochemical analyses elucidate that the Ru center could interact with both CO and amorphous Li C O 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 at a current density of 300 mA g . Our work provides a new avenue to improve the electrochemical performance of Li-CO batteries with efficient mobile catalysts.