Protecting a few-layer MoSe2(1−x)S2x heterostructure with a lower barrier as prolonged high-rate anode for Na+ batteries

Abstract

Here, S-doped MoSe2(1−x)S2x protected by nitrogen-doped multiwall carbon nanotubes (NMWCNTs) and carbon is prepared by sulfuration/selenization through a high-temperature calcination treatment. The S-doped few-layer MoSe2(1−x)S2x with an expanded layer space and a lower diffusion barrier contributes to Na+ adsorption and diffusion, and nitrogen doping is conducive to improved charge-transfer kinetics. Therefore, as an anode for Na+ batteries, S-doped PEG-200–2-C@MoSe2(1−x)S2x@NMWCNT delivers excellent sodium storage performance (440 mA h g-1 at 0.1 A g-1), and long-term cycle stability (240 mA h g-1 after 500 cycles at 5 A g-1, 198 mA h g-1 after 1000 cycles, 180 mA h g-1 after 1900 cycles). These results provide a novel synthesis strategy for the synthesis of high-performance composites to improve the Na+ storage ability.