Phase inversion synthesis of Fe3O4@NC composites with superior lithium

The N-doped carbon coated Fe3O4 composites (Fe3O4@NC) are successfully fabricated on a polyacrylonitrile (PAN) phase inversion method and subsequently annealing. Compared with common electrospinning method, needing delicate equipment and strict reaction conditions, this method is facile and ingenious to synthesize PAN-based composites or carbon-coated materials. Applied to lithium ion batteries (LIBs) anode, the Fe3O4@NC composite exhibits a large specific capacity of 981 mAh g(-1) at 0.2 A g(-1) after 500 cycles, an outstanding rate capability and a superior long-term high-rate cycling performance (632 mAh g(-1) at 1 A g(-1) after 900 cycles). Its excellent electrochemical performance is attributed to the thin carbon layers on the surface of Fe3O4 nanoparticles, which can not only enhance the electron conductivity, but also buffer the volume change of Fe3O4 nanoparticles during lithiation/delithiation. Moreover, the doped nitrogen atoms derived from PAN can lead to more defects in electrode material, which benefits to the electrochemical performance of Fe3O4@NC composites. (C) 2020 Elsevier B.V. All rights reserved.