Graphene oxide sheets-induced growth of nanostructured Fe3O4 for a high-performance anode material of lithium ion batteries

Abstract

Nanostructured Fe₃O₄ is intrinsically prone to aggregation, which hinders insertion and extraction of lithium ions. To overcome this problem, we adopt graphene oxide sheets (GOS) and induce growth of nanostructured Fe₃O₄ on the GOS in the presence of hexamethylenetetramine (HMT). During the synthetic process, GOS provides a template to regulate the growth of nanostructured Fe₃O₄ and the HMT is able to coordinate with Fe³⁺ and control its hydrolysis rate. After the annealing process, GOS is reduced to GS (graphene sheets), and Fe₃O₄/GS composite is obtained. In this hierarchical structure, GS is capable of enhancing the electronic transport of Fe₃O₄, and the Fe₃O₄/GS composite has superior electronic conductivity (106 S m⁻¹). Benefitting from the uniform dispersion of the nanosized Fe₃O₄ on GS and the superior electronic conductivity, the obtained Fe₃O₄/GS exhibits prolonged cycling stability (1002 mA h g⁻¹ after 175 cycles at a current density of 0.50 A g⁻¹) and excellent rate capability (715, 647 and 535 mA h g⁻¹ at 1.6, 3.2 and 5.0 A g⁻¹, respectively).