Activated Co in Thiospinel Boosting Li2CO3 Decomposition in Li−CO2 Batteries

Abstract Catalytic reactions mainly depend on the adsorption properties of reactants on the catalyst, which provides a perspective for the design of reversible lithium−carbon dioxide (Li−CO 2 ) batteries including CO 2 reduction (CO 2 RR) and CO 2 evolution (CO 2 ER) reactions. However, due to the complex reaction process, the relationship between the adsorption configuration and CO 2 RR/CO 2 ER catalytic activity is still unclear in Li ─ CO 2 batteries. Herein, taking Co 3 S 4 as a model system, nickel (Ni substitution in the tetrahedral site to activate cobalt (Co) atom for forming multiatom catalytic domains in NiCo 2 S 4 is utilized. Benefiting from the special geometric and electronic structures, NiCo 2 S 4 exhibits an optimized adsorption configuration of lithium carbonate (Li 2 CO 3 ), promoting its effective activation and decomposition. As a result, the Li−CO 2 batteries with NiCo 2 S 4 cathode exhibit remarkable electrochemical performance in terms of low potential gap of 0.42 V and high energy efficiency of 88.7%. This work provides a unique perspective for the development of highly efficient catalysts in Li−CO 2 batteries.