Spindle-like Fe7S8/N-doped carbon nanohybrids for high-performance sodium ion battery anodes

Iron sulfides have been considered as one of the most promising candidates for sodium ion battery anode materials due to their high theoretical capacity and low cost. In this work, spindle-like Fe 7 S 8 with nitrogen-doped carbon (Fe 7 S 8 /N-C) nanohybrids are successfully synthesized via a solvothermal method by sulfidation iron-based metal organic framework (FeMOF). As sodium ion battery anodes, Fe 7 S 8 /N-C nanohybrids exhibit high reversible capacity of 450.8 mAh·g −1 at 200 mA·g −1 , and 406.7 mAh·g −1 at 500 mA·g −1 even after 500 cycles. They also show excellent rate properties and delivering the capacity of 327.8 mAh·g −1 at a very high current density of 3.2 A·g −1 . These outstanding electrochemical performances can be attributed to the unique structure of Fe 7 S 8 /N-C nanohybrids. The nanoscale dimension in their size can be beneficial for facile ion and electron transports…