In-situ pyrolysis preparation of Fe3O4@CNTs/CC as binder-free anode for sodium-ion batteries

N-doped carbon nanotubes (CNTs) coated Fe3O4 nanoparticles were prepared on flexible carbon cloth (CC) by in situ thermal decomposition method. The obtained Fe3O4@CNTs/CC composites have a three-dimensional network structure. The carbon nanotubes on the flexible carbon cloth can increase the conductivity of the electrode and alleviate the volume change of the active material Fe3O4 during sodium storage. The discharge capacity is 363.6 mAh g−1 after 200 cycles at a current density of 0.2 A g−1. The Fe3O4@CNTs/CC delivers stable discharge capacity of 542, 403, 312, 191, and 152 mAh g−1 at 0.1, 0.5, 1, 2 and 3 A g−1, respectively, having good rate performance.