A Simple and Scalable Method for Preparing Natural Molybdenite-Based MoS2–Graphene Oxide Composite Anodes via Ultrasonic Exfoliation Combined with a Solvothermal Process

Abstract

Starting from natural molybdenite concentrate, this study addresses the challenges of impurity content, compact layer stacking, and poor conductivity that hinder its use as a lithium-ion battery (LIB) anode. Impurities such as Si and Fe were effectively removed through a simple hydrothermal alkali leaching combined with acid leaching process. Few-layer MoS₂ was then obtained via liquid-phase exfoliation using N-methyl-2-pyrrolidone and isopropanol solvents. To enhance interfacial interaction and conductivity, MoS₂–Graphene oxide (GO) composites were synthesized through a solvothermal route. The effects of solvent ratio and GO content on the structure and electrochemical performance were systematically investigated. The optimal water/ethanol (1:5) solvent enabled uniform nanosheet exfoliation with a low charge-transfer resistance (R_ct = 45.1 Ω). The composite with 20 wt% GO delivered a high reversible capacity of 940.7 mAh g⁻¹ at 0.1 A g⁻¹, maintained 555.4 mAh g⁻¹ at 2.0 A g⁻¹, and retained 610 mAh g⁻¹ after 200 cycles at 0.5 A g⁻¹. The synergistic interaction between few-layer MoS₂ and the conductive GO network accelerates electron/ion transport and enhances structural stability, providing a sustainable route to upgrade natural molybdenite for high-performance LIB anodes.

Graphical Abstract