Porous pyrrhotite Fe7S8 nanowire/SiOx/nitrogen-doped carbon matrix for high-performance Li-ion-battery anodes

Iron sulfides, known as attractive anode materials for rechargeable lithium-ion batteries, have been extensively studied. Nevertheless, low electrical conductivity and huge volume expansion of iron sulfides hinder its practical applications. Herein, a novel method was developed to synthesize ternary porous Fe7S8 nano-wires/SiOx /nitrogen-doped carbon matrix by facile hydrothermal method and subsequent sulfidation derived from bamboo leaves. The SiOx/nitrogen-doped carbon matrix can ensure the growth of nanowires, maintain the structural stability, improve the conductivity and provide improved capacity of Fe7S8. The 3D matrix structure and porous properties of Fe7S8 nanowires effectively relieve the volume change upon the insertion/extraction of Li+. The Fe7S8/SiOx/nitrogen-doped carbon anode exhibited a superior discharge capacity of 1060.2 mA h g(-1) at 200 mA g(-1), along with good long cycling performance of 415.8 mA h g(-1) at the 1000th cycle at 5 A g(-1). The facile strategy for preparing ternary Fe7S8 composites with superb LIB electrochemical performances demonstrates a great potential in electrochemical energy storage. (C) 2019 Elsevier Inc. All rights reserved.