Topochemical synthesis of ultrathin nanosheet-constructed Fe3O4 hierarchical structures as high-performance anode for Li-ion batteries

Two-dimensional nanosheets and their assembles have attracted considerable attention as high-performance anode materials for Li-ion batteries because of their short transport lengths and robust structures. In this work, Fe3O4 hierarchical structures assembled by porous ultrathin nanosheets are prepared from the topochemical conversion of Fe-glycolate precursor obtained via a facile refluxing process. The flower-like hierarchical nanostructures have a size of ~ 2.5 µm constructed from ultrathin nanosheet building blocks with thickness of ca. 10 nm. When used as an anode electrode, the as-prepared Fe3O4 hierarchical nanostructures demonstrate excellent electrochemical properties with a reversible and stable capacity as high as 964.3 mAh g−1 at 500 mA g−1 after 100 cycles, and superior rate capability of 487 mAh g−1 at a high current density of 8 A g−1.