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

Abstract

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%.