Pod-Like Fe7S8@N−C Nanowires for High Performance Sodium Ion Batteries

One dimensional Fe7S8@N−C nanocomposite, consisting of Fe7S8 nanoparticles homogeneously embedded in N-doped carbon nanowires, was synthesized by a facile hydrothermal-annealing process. As an anode material for sodium-ion batteries, the electrode exhibited capacities of 481 mA h g−1 after 1000 cycles at 5 A g−1 and 591 mA h g−1 at 200 mA g−1 with a retention ratio of 91 %. The excellent rate performance and cycling stability can be attributed to the synergistic effects of the one-dimensional N-doped carbon and ultra-small Fe7S8 particles, which will improve electrical conductivity and alleviate the volume expansion of the electrode during cycling. This work will afford a great reference for further development of iron sulfides-based anode materials towards high-performance sodium-ion batteries.