Atomically precise Ag30Pd4 nanocluster as efficient polysulfides redox catalyst in Li-S batteries

Abstract

Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides (LiPSs) in lithium-sulfur batteries (Li-S), yet which has been overlooked in current studies. In this work, structurally defined Ag30Pd4 nanoclusters were loaded onto reduced graphene oxide (Ag30Pd4/rGO) as a modification material for polypropylene (PP) separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries. This unique d-π combination promotes charge transfer, influences overall charge states, and further enhances adsorption energies in potential reaction pathways with lithium polysulfides. Consequently, the Ag30Pd4/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026% per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm−2 excellent performance even with lean electrolyte and high sulfur loading (9.7 mg cm−2). This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithium-sulfur battery performance.