High-temperature solvent-free sulfidation of MoO3 confined in a polypyrrole shell: MoS2 nanosheets encapsulated in a nitrogen, sulfur dual-doped carbon nanoprism for efficient lithium storage

Abstract

Hierarchical nanostructured metal sulfides in a rectangular prism shape are highly attractive as a promising electrode material for lithium ion energy storage. Herein, we develop a simultaneous pyrolysis and sulfidation strategy to synthesize yolk-shelled MoS₂@nitrogen, sulfur dual-doped carbon (MoS₂@NSC) nanoprisms. Upon encapsulating MoO₃ nanoprisms into a polypyrrole (PPy) shell, a high-temperature solvent-free sulfidation reaction from MoO₃ to hierarchical MoS₂ nanosheets could take place within the PPy nanoreactor, and the PPy nanoreactor simultaneously converted into NSC hollow nanoprisms. Owing to the compositional and structural superiority, the MoS₂@NSC nanoprisms with a well-defined sheet-in-prism superstructure manifested enhanced electrochemical activity as a promising anode material for lithium-ion batteries including a high reversible capacity (960 mA h g⁻¹ at 0.1 A g⁻¹⁾, excellent cycling stability (800 mA h g⁻¹ at 0.1 A g⁻¹ up to 300 cycles), and superior rate capability (440 mA h g⁻¹ at 2 A g⁻¹).