Fe3O4 nanoparticle anchored layered graphene films for high performance lithium storage

Abstract

A flexible and binder-free Fe₃O₄/graphene film was prepared through the vacuum filtration of Fe₃O₄/GO suspensions, followed by an annealing process. Cross-sectional SEM images of the sandwiched films show that Fe₃O₄ nanoparticles homogeneously decorated onto layered graphene nanosheets and formed a nanoporous network structure. Thus, the composite film provided effective channels to promote electrolyte penetration when used as an anode for Li-ion batteries. Moreover, the good attraction between Fe₃O₄ and graphene is attributed to hydrogen bonding or intermolecular forces, making them beneficial for charge transfer. The unique film with excellent mechanical stability also can buffer the volume expansion during the Li-ion insertion/extraction process. After electrochemical tests, the as-prepared binder-free Fe₃O₄/graphene hybrid lamellar films demonstrated excellent cyclic retention with the specific capacity of 681.2 mA h g⁻¹ after 50 cycles, which is 3 times higher than the discharge capacity of 222.0 mA h g⁻¹ for pure Fe₃O₄, as well as good rate capability, making them promising candidates for use as anodes for Li-ion batteries.