Metal Nanoclusters as a Superior Polysulfides Immobilizer toward Highly Stable Lithium-Sulfur Batteries

Due to their high designability, unique geometric and electronic structures, and surface coordination chemistry, atomically precise metal nanoclusters are an emerging class of functional nanomaterials at the forefront of materials research. However, the current research on metal nanoclusters is mainly fundamental, and their practical applications are still uncharted. The surface binding properties and redox activity of Au₂₄ Pt(PET)₁₈ (PET: phenylethanethiolate, SCH₂ CH₂ Ph) nanoclusters are herein harnessed as an high-efficiency electrocatalyst for the anchoring and rapid conversion of lithium polysulfides in lithium-sulfur batteries (LSBs). Au₂₄ Pt(PET)₁₈ @G composites are prepared by using the large specific surface area, high porosity, and conductive network of graphene (G) for the construction of battery separator that can inhibit polysulfide shuttle and accelerate electrochemical kinetics. Resultantly, the LSB using a Au₂₄ Pt(PET)₁₈ @G-based separator presents a high reversible specific capacity of 1535.4 mA h g^-1 for the first cycle at 0.2 A g^-1 and a rate capability of 887 mA h g^-1 at 5 A g^-1 . After 1000 cycles at 5 A g^-1 , the capacity is 558.5 mA h g^-1 . This study is a significant step toward the application of metal nanoclusters as optimal electrocatalysts for LSBs and other sustainable energy storage systems.