Nanostructure Fe2O3 surface-coating on MnO2 microspheres as high rate performance anode materials for lithium-ion batteries

Abstract

Manganese dioxide (MnO2) anode materials with high energy and power density have attracted wide attention in lithium-ion batteries (LIBs). However, the poor rate capability and inferior cycling stability hindered their commercial applications. To address the issues, we designed and synthesized MnO2 @Fe2O3 composite microspheres by a solvothermal treatment and subsequent annealing process, on which Fe2O3 nanoparticles are coated on the surface of MnO2 microspheres with a diameter of about 2 µm. The Fe2O3 thin protective film on the surface of MnO2 alleviates the volume change of MnO2 and the dissolution of Mn element during cycling, and improves the Li+ diffusion coefficient of the electrode materials through the kinetics analysis. The MnO2 @Fe2O3 microspheres deliver excellent rate capacity of 296.2 mA h g −1 at a high current density of 6.4 A g −1, and superior reversible capacity of 675.4 mA h g −1 and 784.6 mA h g −1 after 150 cycles at 100 mA g −1 and after 1000 cycles at 500 mA g −1, respectively. The enhanced electrochemical performance is attributed to the synergistic effect of different components. The results indicate that MnO2@Fe2O3 composite microspheres will be a promising anode materials for superior performance in LIBs.