Ultrasmall Fe3O4 Nanoparticle/MoS2 Nanosheet Composites with Superior Performances for Lithium Ion Batteries

A novel composite consisting of graphene-like MoS2 nanosheets and ultrasmall Fe3O4 nanoparticles (approximate to 3.5 nm) is synthesized as an anode for lithium ion battery application. In such composite anode, MoS2 nanosheets provide flexible substrates for the nanoparticle decoration, accommodating the volume changes of Fe3O4 during cycling process; while Fe3O4 nanoparticles primarily act as spacers to stabilize the composite structure, making the active surfaces of MoS2 nanosheets accessible for electrolyte penetration during charge/discharge processes. Owing to the high reversible capacity provided by the MoS2 nanosheets and the superior high rate performance offered by ultrasmall Fe3O4 nanoparticles, superior cyclic and rate performances are achieved by Fe3O4/MoS2 anode during the subsequent electrochemical tests, delivering 1033 and 224 mAh g(-1) at current densities of 2000 and 10 000 mA g(-1), respectively.