Interfacial reinforcement structure design towards ultrastable lithium storage in MoS2-based composited electrode

Abstract

Huge volume expansion and inferior electrical conductivity are the two main obstacles to limit the practical applications of high-capacity molybdenum disulfide (MoS2) materials, which has been recognized as ideal anode materials for rechargeable lithium-ion batteries. Herein, an interfacial reinforcement structure design is proposed by conformally growing few-layered MoS2 nanosheets on carbon coated ultralong TiO2 nanotubes (TiO2@[email protected]2) to stabilize the solid electrolyte interface (SEI) of MoS2-based electrode. The interlayer carbon coating on TiO2 nanotubes effectively improves the interfacial contact between MoS2 nanosheets and TiO2 nanotubes by forming Ti-O-C and C-S chemical bonds between TiO2/carbon coating and MoS2/carbon coating, respectively, avoiding MoS2 nanosheets detaching from TiO2 nanotubes. Meanwhile, the carbon coating serves as a buffering cushion to alleviate mechanical strain at the interface of MoS2 nanosheets and TiO2 nanotubes. Besides, it enhances the adsorption performance of Li ions on the surface of MoS2 and at the interface sites between MoS2 and TiO2. While three-dimensional rigid TiO2 nanotubes networks work as mechanical support to suppress reaggregating and restacking of MoS2 nanosheets, and provide fast transportation expressways for electrons/ions. Thus, the TiO2@[email protected]2 electrode exhibits ultrafast charge/discharge capability, a high reversible capacity of 1150 mAh g−1 at 0.1 A g−1, and superior cycling performance with 90% capacity retention after 1500 cycles at 1.0 A g−1. This interfacial reinforcement structure design provides valuable experience to benefit rational design of alloy/conversion-typed materials electrode with high-performance.