Core–shell CeO2 micro/nanospheres prepared by microwave-assisted solvothermal process as high-stability anodes for Li-ion batteries

Abstract

Core–shell CeO2 micro/nanospheres are prepared via microwave-assisted solvothermal process followed by calcination in air. The reaction time is only 30 min. Structure information, phase, and morphologies of the as-synthesized powder are characterized by X-ray diffraction (XRD), scan electron microscope (SEM), and transmission electron microscope (TEM), respectively. The heterogeneous contraction originated from the non-equilibrium heat treatment may be responsible for the formation of core-shelled structure. Charge–discharge test and electrochemical impedance spectroscopy (EIS) are carried out by using the as-prepared CeO2 as an anode material for lithium-ion batteries. When tested in 0.01–1.5 V at 0.2 mA cm−2, the initial discharge capacity is 454.2 mAh g−1 and stabilized reversibly at about 327.0 mAh g−1 after 100 cycles. The special core–shell micro/nanostructure is more capable of buffering the volume change, resulting in enhanced electrochemical performances. This exploring about the core–shell micro/nanomaterial may direct a new generation electrode material of Li-ion batteries.