Anchoring 1T/2H MoS2 nanosheets on carbon nanofibers containing Si nanoparticles as a flexible anode for lithium-ion batteries

Silicon-based (Si) materials have received exceptional attention as the most promising fall-back option for lithium-ion batteries (LIBs) due to their high specific capacity. Regrettably, the huge volume variation, inferior intrinsic conductivity, and low initial Coulombic efficiency (ICE) of Si-based materials are the main obstacles hampering their practical application. Herein, to overcome these issues, Si@carbon nanofibers (CNFs) were fabricated by encapsulating Si nanoparticles (Si NPs) in CNFs perfectly, which ensured a fast one-dimensional electronic pathway on the basis of relieving the volume expansion. In addition, 1T/2H MoS2 nanosheets with excellent electrical connectivity were vertically assembled on the surface of the Si@CNFs to enhance the electrical conductivity of the composites. The Si NPs encapsulation by CNFs and 1T/2H MoS2 avoided their exposure to the electrolyte, which improved the ICE. The hierarchical microstructure of the Si@CNFs@1T/2H MoS2 flexible film as a self-supporting electrode avoided the need for the introduction of inactive materials and maximized the energy-storage capacity of the active material. The Si@CNFs@1T/2H MoS2 electrode also offers exciting opportunities for developing flexible and free-standing anode materials for LIBs since it exhibited an excellent rate capability and cycling performance with a high ICE of 94.5%.

Automated summary

Si@carbon nanofibers (CNFs)@1T/2H MoS2 composite material was fabricated to improve the conductivity and initial Coulombic efficiency of silicon-based materials, and to overcome the issues of volume variation. The material exhibited excellent rate capability and cycling performance, making it a promising candidate for flexible and free-standing anode materials for lithium-ion batteries.