Synergistic engineering of a carbon-coated Cu_1.81S/ZnS composite via a high-temperature mixing method for enhanced...

Graphite anodes are limited by low capacity and instability. Conversion-type transition metal sulfides (TMSs) offer high energy density, yet single-component TMSs suffer from rapid capacity decay owing to volume changes, hindering their practical implementation. Herein, a carbon-coated Cu_1.81S/ZnS composite (Cu_1.81S/ZnS@C) is rationally designed and synthesized via a high-temperature mixing method (HTMM) in the hydrothermal process and the carbonization process. This unique structure integrates ZnS nanoparticles with Cu_1.81S nanosheets, uniformly encapsulated within a conductive carbon matrix. When evaluated as an anode material, the Cu_1.81S/ZnS@C composite exhibits significantly enhanced lithium storage performance compared to its single-component counterparts. It delivers a high reversible capacity of 571.4 mAh g^-1 at 1 A g^-1 after 550 cycles. Kinetic analysis reveals a predominant pseudocapacitive contribution, accounting for its fast reaction kinetics. The outstanding electrochemical performance stems from the synergistic coupling of the Cu_1.81S, ZnS, and carbon components. This multi-component integration collectively provides abundant active sites and establishes highly efficient pathways for both ionic diffusion and electronic conduction. Overall, this study highlights the effectiveness of a rationally designed heterostructure with multi-interface synergy in advancing high-performance metal sulfide anodes for next-generation energy storage systems.