CuFe2O4 network,prepared via the electrostatic spray deposition technique,with high reversible capacity and long cycle lifetime for lithium ion battery anode material has been reported.The reversible capacity can be further enhanced by coating high electronic conductive polypyrrole（PPy）.At the current density of 100mA·g-1.Li/CuFe2O4 electrode delivers a reversible capacity of 842.9 mAh·g-1 while the reversible capacity of Li/PPy-coated CuFe2O4 electrode increases up to 1106.7 mAh-g’.A high capacity of 640.7 mAhg＂1 for the Li/PPy-coated CuFe2O4electrode is maintained in contrast of 398.9 mAh·g-1 for CuFe2O4 electrode after 60 cycles,which demonstrates good electrochemical performance of the composite due to the increase of electronic conductivity.The electrochemical impedance spectroscopy（EIS） further reveals that the Li/PPy-coated CuFe2O4 electrode has a lower charge transfer resistance than the Li/CuFe2C〉4 electrode.
Graphene-wrapped Fe2O3nanorings(RGO/Fe2O3)were synthesized by a facile approach,which assembled with graphene and the Fe2O3nanorings precursor through the colloidal coagulation effect at room temperature.The uniform Fe2O3nanorings prepared by hydrothermal routes were homogeneously distributed and well wrapped by graphene.When tested as anode for lithium ion batteries,RGO/Fe2O3exhibits a high capacity and good cycling stability.This could be attributed to the interaction of ring-shaped structure and graphene sheets,which inherit the good kinetic property of Fe2O3nanorings and enhance the structural integrity with graphene sheets’support.
