Ultrahigh‐Content CoP Cluster as a Dual‐Atom‐Site Electrocatalyst for Accelerating Polysulfides Conversion in Li–S Batteries

Single-atom catalysts (SACs) show high catalytic efficiency in accelerating conversion of lithium polysulfides (LiPS), and are thus promising for suppressing the shuttle effect observed in lithium-sulfur batteries (LSBs); however, single-atom catalytic sites with low content of catalysts largely restrict their catalytic effect. Herein, a Co-P cluster supported by a N-doped carbon matrix (Co-P cluster/NC) with atomic-level dispersion and an ultrahigh content (25.5 wt.%) of Co atoms is fabricated via an in situ low-temperature phosphorization strategy and employed as a dual-atom-site catalyst for catalyzing LiPS conversion. The Co-P cluster/NC with abundant unsaturated Co-P coordination provides dual-atom sites of Co and P to dynamically adsorb/desorb sulfur species and Li+ ions, respectively, synergistically promoting the conversion of LiPS. The dual-atom-site catalytic mechanism is evidenced by substantial characterizations including X-ray absorption fine structure measurements and density functional theory calculations. Consequently, the S@Co-P cluster/NC cathode shows superior cycling and rate performance. Even at a high sulfur loading of 6.2 mg cm(-2), a high areal capacity of 6.5 mAh cm(-2) that surpasses most commercial lithium-ion batteries can be achieved. This study opens a new avenue in the development of advanced catalysts with new catalytic mechanisms for high-performance LSBs.