Enhanced Electrochemical Performance of Aprotic Li‐CO2 Batteries with a Ruthenium‐Complex‐Based Mobile Catalyst

Abstract

Li‐CO 2 batteries are regarded as next‐generation high‐energy‐density electrochemical devices, with great importance in the understanding of Li‐air batteries and promising potential for application in the aviation industry. 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.