One-dimensional Fe7S8@C nanorods as anode materials for high-rate and long-life lithium-ion batteries

Abstract

One-dimensional (1D) Fe7S8@C nanorods for high-performance Li storage were successfully designed and manufactured via the hydrothermal method and subsequent poly(dopamine) coating. The carbon coating obtained via high-temperature carbonisation significantly enhanced the conductivity of iron sulfide (Fe7S8@C nanorods). In addition, the 1D material had relatively high stability. Therefore, the combination of 1Dmaterials and the carbon structure (Fe7S8@C nanorods) not only improved the intercalation and deintercalation of Li ions but also had outstanding stability. When used as an anode material for LIBs, the Fe7S8@C nanorods maintained a discharge capacity of 825.45 mA h g−1 after 100 cycles at a current density of 100 mA g−1, showing excellent cyclic stability and capacity retention. More importantly, the Fe7S8@C nanorods exhibited a very high reversible capacity (433.31 mA h g−1) even after 1000 cycles at a high current density of 2000 mA g−1. These results indicate that this unique 1D carbon coating structure can effectively improve the electrochemical performance of materials. Moreover, the results show that the prepared Fe7S8@C nanorods have broad application prospects for LIBs.