Controlled synthesis of α-Fe2O3@rGO core–shell nanocomposites as anode for lithium ion batteries

Abstract

The fine shape control of metal oxides nanocrystal and component are the key for the preparation of high-performance metal oxides/graphene nanocomposites. Herein, a simpler and practicable in situ one-pot approach was used to synthetize α-Fe2O3@reduced graphene oxide (rGO) core–shell nanocomposites. By controlling the amount of hydrazine hydrate and GO in reaction system, the shape of α-Fe2O3 nanocrystals can be tailored from spindle gradually to ellipsoid and quasi-sphere, and the thickness of enwrapped rGO can also be finely controlled. The as-prepared α-Fe2O3@rGO core–shell composites showed much better lithium storage performance than bare α-Fe2O3 nanocrystals. Owing to the core–shell structure and the high conductivity and stability of rGO nanosheet, the quasi-sphere-α-Fe2O3@rGO composites delivered a high reversible specific capacity up to 971 mAh g−1 at the current density of 0.2 A g−1, retaining 530 mA h g−1 at 2 A g−1 and 361 mA h g−1 at 5 A g−1 after 800 cycles with only 0.05% decay per-cycle. Moreover, the facile approach can provide a new strategy for the fabrication of other shape-size dependent, functional, and multicomponent graphene-based composites.