Amorphous codoped SnS/CNTs nanocomposite with improved capacity retention as an advanced sodium-ion battery anode

Tin-based chalcogenides are considered as a promising anode material for sodium-ion batteries yet they suffer from poor electronic conductivity, initial coulombic efficiency and capacity retention. Herein, using facile solvothermal route, cauliflower-like SnS/CNTs and codoped SnS/CNTs nanocomposites were synthesized. Heteroatom dopants in codoped SnS/CNTs create an amorphous structure which provides sufficient space to release volumetric strains induced during sodiation/desodiation, resulting in superior capacity retention and initial coulombic efficiency of 44% as compared to 39.4% for SnS/CNTs and 36% for SnS. Carbon nanotubes create a framework by connecting cauliflower-like SnS together and at 0.1 A g⁻¹, it delivers a reversible capacity of 183.3 mAh g⁻¹ after 50 cycles in SnS/CNTs, which is more than twice as high as is delivered by pure SnS, and also with a very small resistance to charge transfer. Therefore, these novel nanocomposites provide a robust platform for application in sodium-ion batteries.