Atomically Dispersed Co-Ru Dimer Catalyst Boosts Conversion of Polysulfides toward High-Performance Lithium-Sulfur...

The sluggish sulfur redox reaction in lithium-sulfur (Li-S) batteries triggers the development of highly active electrocatalysts for accelerating the polysulfides conversion kinetics. Rational design of catalysts with satisfactory active sites and high atom utilization toward multistep sulfur-based conversion is much desired but remains challenging. Here, it is shown that the well-designed Co-Ru dimer sites confined on carbon matrix could effectively manipulate the sulfur-involved conversion reactions and thus improve Li-S batteries performance. The orbital coupling of Co-Ru dimer induces the orbital regulation for the atomic pair, resulting the favored lithium polysulfides adsorption strength and lowed conversion energy barrier, as confirmed by systematic electrochemical characterizations and theoretical calculation. Besides, the intrinsic catalytic activity of Ru from Co-Ru moiety also accelerates the Li₂S dissociation reaction. Taken together, the as-constructed Co-Ru dimer sites render the Li-S battery with excellent performance, delivering energy density of 468 Wh kg^-1 of total assembled pouch cell. This study offers a rational design of catalysts for boosting the catalytic performance in Li-S batteries.