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

Abstract

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 (≈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.