Effects of Fe3O4 loading on the cycling performance of Fe3O4/rGO composite anode material for lithium ion batteries

Well dispersed Fe3O4 nanoparticle suspensions with grain size of about 9 nm were coprecipitated and then compounded with different amount of GO (graphite oxide) followed by reduction of GO to obtain Fe3O4/rGO (reduced graphite oxide) composites with different component ratios. The as-obtained Fe3O4/rGO composites were used as anode materials for lithium ion batteries to investigate the best component ratio of the composite for the cycling performance. Fe3O4/rGO composite electrode containing 44.9 wt% Fe3O4 displayed the best cycling capacity of above 300 mA h g−1 at 1000 mA g−1 after 100 cycles and it was interesting to find that the trend of impedance spectra of Fe3O4/rGO electrodes after some cycles of electrochemical reactions can be well related to the overall cycling performances.