One-pot Biotemplate Synthesis of FeS sub(2) Decorated Sulfur-doped Carbon Fiber as High Capacity Anode for Lithium-ion Batteries

Pyrite FeS sub(2) decorated sulfur-doped carbon (FeS sub(2)-C) fibers have been successfully synthesized by a facile bio-templating method and applied as the anode material for lithium ion batteries (LIBs). Cotton was used as both the carbon source and the template. SEM and TEM results showed that the FeS sub(2) nanoparticles fabricated using 0.2 M FeSO sub(4) were uniformly embedded in or attached on the surface of the carbon fibers. FeS sub(2)-C synthesized with 0.2 M FeSO sub(4) showed the best cycle stability and rate capability, which retained a high reversible specific capacity of 689 mAh g super(-1) after 100 cycles. The specific capacities are about 1200, 900, 700, 550 and 400 mAh g super(-1) after every 10 cycles at 0.1, 0.2, 0.5, 1 and 2 A g super(-1). The excellent electrochemical performance can be ascribed to the highly conductive sulfur-doped carbon and the homogeneous distribution of FeS sub(2) nanoparticles. It is believed that the S-doped carbon matrix acts as an effective buffer layer helping relieve the volume strain as well as a hinder preventing FeS sub(2) from aggregating during cycling, which ensure the high electrochemical performance. This kind of low-cost anode with high specific capacity and improved cycling stability show potential application for high capacity lithium-ion batteries.