Three-dimensional sponge-like architectured cupric oxides as high-power and long-life anode material for lithium rechargeable batteries

Abstract

Cupric oxide (CuO) nanoparticles (NPs) with three-dimensional (3D) sponge structure are obtained through the sintering of Cu NPs at 360 degrees C. Their morphology is analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and their crystal structure is checked by X-ray diffraction. CuO NPs have a 3D porous structure. The NPs are assembled to form larger secondary particles with many empty spaces among them, and they have a CuO phase after the heat treatment. CuO NPs with this novel architecture exhibit good electrochemical performance as anode material. The anode material with a sponge-like structure is prepared at 360 degrees C, as the Li-ion battery exhibits a high electrochemical capacity of 674 mAhg(-1). When the sample is sintered at 360 degrees C, the charge/discharge capacities increase gradually and cycle up to 50 cycles at a C/10 rate, exhibiting excellent rate capability compared with earlier reported CuO/CuO-composite anodes. Electrochemical impedance spectroscopy (EIS) measurements suggest that the superior electrical conductivity of the sample sintered at 360 degrees C is the main factor responsible for the improved power capability. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.