Novel one-step gas-phase reaction synthesis of transition metal sulfide nanoparticles embedded in carbon matrices for reversible lithium storage

Abstract

This report presents a novel one-step method based on the gas-phase reaction between metallocenes and sulfur for synthesizing the nanocomposites of transition metal sulfide nanoparticles embedded in carbon matrices (TMS@C). Various nanocomposites including FeS@C, Cr₂S₃@C and NiS₂@C have been successfully synthesized by using ferrocene, chromocene and nickelocene, respectively. The SEM investigations evidence that the TMS nanoparticles are evenly distributed in the in situ formed carbon matrices, demonstrating that this novel method is an easy way to synthesize homogenous TMS-based nanocomposites with well-controlled nanostructures. As the anodes for lithium ion batteries (LIBs), the as-prepared TMS@C electrodes exhibit excellent rate capability and high reversible capacity. For example, a high reversible capacity of 550 and 480 mA h g⁻¹ can be retained for the FeS@C anode even after 350 cycles at a current density of 0.1 A g⁻¹ and 500 cycles at 0.5 A g⁻¹, respectively. The TEM investigations on the 100^th discharged and recharged electrodes demonstrate superior structural stability against repeated lithiation/delithiation of the FeS@C. These impressive results indicate that this novel approach is a promising way to synthesize high-performance TMS electrodes for highly reversible lithium storage.