Interlayered MoS2/rGO thin film for efficient lithium storage produced by electrospray deposition and far-infrared reduction

Abstract

Three-dimensional (3D) interlayered composites offer many advantages for energy storage owing to their fast charge transfer kinetics. In this study, the interlayered molybdenum disulfide (MoS2)/graphene (rGO) composites were prepared by electrospray deposition and far-infrared reduction (FIR) processes from single layer MoS2 and graphene nanosheets. Such hierarchical layer-by-layer assembling thin film structure is formed by the driving force of electrostatic interactions between MoS2 and graphene oxide (GO) via the electrospray process. Subsequently, a simple and efficient FIR irradiation (~5 min) process was carried out to reduce the as-prepared MoS2/GO thin film in ambient air using a commercial convection oven. The electro-spraying and FIR reduction processes will jointly help to prevent surface migration and agglomeration of MoS2 and graphene nanosheets, enable efficient electron transfer between the rGO and MoS2 nanosheets, and realize fast lithium storage. As expected, the binder-free MoS2/rGO thin film electrode delivers an outstanding specific capacity (1242.7 mAh g−1 at 0.1 A g−1), high-rate capability (533.7 and 361.6 mAh g−1 at 2.0 and 5.0 A g−1, respectively) and long cycle-life (99.6% capacity retention after 1000 cycles at 2.0 A g−1). More interestingly, the simple economic and efficient strategy for fabricating interlayered MoS2/rGO composites containing electrode can be extended to other electrode materials for energy storage.