Rapid synthesis of Cr-doped γ-Fe2O3/reduced graphene oxide nanocomposites as high performance anode materials for lithium ion batteries

Cr-doped γ-Fe2O3/reduced graphene oxide (rGO) nanocomposites are successfully synthesized through a rapid and environmentally friendly microwave method in just 10 min. Under the microwave heating, graphene oxide (GO) is reduced to rGO with ferrous ion (Fe2+) served as the reductant, and Cr-doped γ-Fe2O3 nanoparticles are synthesized in the meantime. It is found that Cr doping can not only affect the phase of Fe2O3, but also has an effect on the morphology, the electrical conductivity and the electrochemical properties. As anode material for lithium ion batteries, the 4.0 at% Cr-doped γ-Fe2O3/rGO nanocomposites exhibit the highest reversible capacity of 1060 mAh g−1 after 100 cycles (66.9% of the initial capacity) at a current density of 100 mA g−1. Furthermore, when assembled as a full cell against commercial cathode including LiCoO2 and LiNi1/3Mn1/3Co1/3O2, the battery shows promising cycling performance. The superior electrochemical performance could be attributed to the uniform nanostructure and the synergistic effect between Fe2O3 and rGO as well as the doping of chromium, which can reduce the size of Fe2O3 particles and improve the electrical conductivity.