Sb2Se3 nanowires encapsulated in multi-walled carbon nanotubes with optimized interface as anodes for lithium-ion batteries

Sb 2 Se 3 has appeared as a highly prospective anode material for lithium-ion batteries (LIBs) owing to its abundant resources, a remarkable theoretical capacity of 670 mA h g −1 , and the presence of both alloy and conversion reaction mechanisms. Nevertheless, its drastic volume change during cycling caused rapid capacity decay. To address these issues, a common approach is to combine Sb 2 Se 3 with carbon materials. In this study, Sb 2 Se 3 encapsulated in multi-walled carbon nanotubes (MWCNTs) were fabricated through a one-step low-pressure vapor-phase reaction, forming the Sb 2 Se 3 @MWCNTs composite. The nanosize effect of Sb 2 Se 3 can alleviate its structural fracture during cycling. MWCNT network is advantageous for electron/ion transport. Subsequently, poly(3,4-ethylenedioxythiophene) (PEDOT), a conjugated polymer, was employed as an electron-enhancing buffer layer to further coat MWCNTs, creating the Sb 2 Se 3 @MWCNTs/PEDOT. More importantly, the PEDOT layer could create a robust solid electrolyte interface (SEI). By adjusting the ratio of Sb 2 Se 3 to MWCNTs, Sb 2 Se 3 @MWCNTs/PEDOT-7:3 composite exhibited a capacity of 648 mAh g −1 after 200 cycles at 0.5 A g −1 and a capacity of 495 mAh g −1 after 970 cycles at 2 A g −1 , demonstrating a highly promising class of high-performance LIB anode materials.