A novel “caterpillar with eggs” mesostructured iron sulfide as an anode for a Li-ion battery displaying stable electrochemical performance

Abstract

Emerging anodes are important for high energy-density lithium-ion batteries. Here, we present a mesostructured FeS₂ comprising nanoparticles embedded in a nanoneedle-assembled nanotube to form a novel “caterpillar with eggs” (CWE) structure. The voids alleviated the volumetric change upon charge–discharge; the nanoneedles-assembled shell provided rapid transport pathways for ions and electrons. The FeS₂ anode exhibited a high capacity of 805.1 mA h g⁻¹ after 500 cycles at 2 A g⁻¹. When cycling at −10 °C and 45 °C, the anode provided capacities of 754.5 and 744.4 mA h g⁻¹ after 100 cycles at 1 A g⁻¹, respectively. This good electrochemical performance will enable our special design to find broad applications for developing high-performance energy-storage systems.