Tailoring Li2CO3 configuration and orbital structure of CoS to improve catalytic activity and stability for Li‐CO2 batteries

Abstract The sluggish reaction kinetics has greatly hampered the development of reversible Li‐CO2 batteries. Especially during charge, high charge voltage and possible side reactions during Li2CO3 decomposition require both high activity and strong durability of catalysts. Herein, a strategy of introducing rich sulfur vacancies is proposed, which tailors the configuration of Li2CO3 and the orbital structure of CoS to realize the dual enhancement. The calculation results show that charge redistribution by sulfur vacancies on the catalyst stretches the adsorbed Li2CO3 and consequently facilitates its decomposition. Moreover, the induced vacancies lower the S 2p band center, promoting the electrochemical stability of sulfides. Therefore, Li‐CO2 batteries with sulfur vacancy‐rich CoS exhibit a low overpotential of 1.07 V after 400 h cycling, while batteries with pristine CoS have a short lifespan that the overpotential exceeds 1.75 V after cycling for 200 h. This study not only proposes a strategy to improve both catalytic activity and stability but also paves new avenues for designing advanced catalysts for Li‐CO2 batteries and beyond. image