The construction of C-coated MoSx-SnS composites and application to highly efficient and durable lithium storage

Abstract

An innovative electrode material, the carbon-coated amorphous MoSₓ/crystalline SnS heterogeneous composite (C-MSnS-X), was synthesized via a coupled hydrothermal synthesis and high-temperature calcination process. By precisely modulating the molar ratio of Mo and Sn precursors, it was determined that the composition with a Mo:Sn ratio of 1:3 (C-MSnS-3) exhibited the most favorable overall electrochemical performance. Electrochemical kinetic analysis revealed that the C-MSnS-3 material demonstrated a high lithium-ion diffusion coefficient in the range of 10⁻⁶ to 10⁻⁹ cm² s⁻¹ and a low charge transfer impedance (27.8 Ω after cycling), indicating excellent ion transport kinetics and interfacial reactivity. When employed as an anode in lithium-ion batteries, the synergistic effect of the heterostructure enabled the electrochemical performance of C-MSnS-3 to significantly exceed that of the single-component C-MS and C-SnS materials. A reversible specific capacity of 956.7 mA h g⁻¹ at 50 mA g⁻¹ was reported, along with a capacity retention rate of 94.4 % after 1600 cycles at a high current density of 2 A g⁻¹ , thereby demonstrating outstanding cycling stability. This study presents a novel strategy for the structural design and performance enhancement of sulfide composite anode materials, thereby establishing an important reference for the development of high-energy-density lithium-ion battery systems.