Improving Effect of Graphene on Electrochemical Properties of Fe₂O₃ Anode Materials

Abstract

Transition metal oxides have a high initial charge-discharge capacity of 800–1000 mAh/g, the electrochemical performance, cyclic performance and rate performance of the composite of transition metal oxide and graphene have been improved due to the unique two-dimensional structure and excellent electrical conductivity of graphene. In this paper, iron oxides materials with different morphs were prepared by different hydrothermal reaction temperatures, and rGO/Fe2O3-175 °C composites with different graphene ratios were synthesized and used in the anode of lithium ion batteries. The results show that nanorod-shaped Fe2O3 had better electrochemical performance than spherical Fe2O3. 0.2rGO/Fe2O3-175 °C had the best cyclic performance, the first cyclic discharge capacity reaches 1372 mAh/g under the current density of 100 mA/g, and the cyclic reversible capacity remained at about 435 mAh/g after 50 cycles, illustrating that nanorods Fe2O3 and graphene composites can greatly buffer the volume expansion of Fe2O3.

Keywords

• iron oxides
• graphene
• anode
• lithium ion batteries
• electrochemical performance