Urchin-like FeS2 hierarchitectures wrapped with N-doped multi-wall carbon nanotubes@rGO as high-rate anode for sodium ion batteries

Transition metal chalcogenides have been investigated as underlying anodes for sodium ion batteries (SIBs). Nevertheless, the unsatisfactory property, which is determined by huge volume variation and low conductivity, restricts their practical applications. The design of micro-nano hierarchitectures is a resultful approach to strengthen structural stability and reaction kinetics during the discharge-charge process. Herein, urchin-like FeS2 hierarchitectures wrapped with reduced graphene oxide and N-doped multi-wall carbon nanotubes (FeS2@N-CNTs@rGO) are designed and synthesized by hydrothermal route. FeS2@N-CNTs@rGO shows high capacity with 578 mAh g(-1) at 0.1 A g(-1), splendid rate property with 419 mAh g(-1) at 5 A g(-1) and preeminent capacity retention (approximate to 100%) over 750 cycles at 2 A g(-1). The reversible phase transformation, capacitive Na+ storage behaviour and micro-nano hierarchitectures are responsible for the outstanding rate performance.

Automated summary

Transition metal chalcogenides have been explored as anode materials for sodium ion batteries, but their practical applications are limited due to unsatisfactory properties. The design of micro-nano hierarchitectures, such as urchin-like FeS2@N-CNTs@rGO, shows high capacity, excellent rate performance, and outstanding capacity retention, attributing to reversible phase transformation, capacitive Na+ storage behavior, and micro-nano structures.