Microwave homogeneous synthesis of porous nanowire Co₃O ₄ arrays with high capacity and rate capability for lithium ion batteries

In this paper, an efficient microwave-assisted homogeneous synthesis approach by urea hydrolysis is used to synthesize cobalt-basic-carbonate compounds. The dimensions and morphology of the synthesized precursor compounds are tailored by changes in the incorporated anions (CO₃^2- and OH^-) under different conditions of temperature and time under microwave irradiation. The wire-like cobalt-basic-carbonate compound self-assembles into one-dimensional porous arrays of Co₃O₄ nanowires constructed of interconnected Co₃O₄ nanocrystals along the [1 1 0] axis after thermal decomposition at 350 °C. The textural characteristics of the Co₃O₄ products have strong positive effects on their electrochemical properties as electrode materials in lithium-ion batteries. The obtained porous nanowire Co ₃O₄ arrays exhibit excellent capacity retention and rate capability at higher current rates, and their reversible capacity of 600 mAh g^-1 can be maintained after 100 cycles at the high current rate of 400 mA g^-1. © 2010 Elsevier B.V. All rights reserved.