Nano-CuO coated LiCoO2: Synthesis, improved cycling stability and good performance at high rates

LiCoO2 nanoparticles were prepared through a sol-gel method, and then appropriate amount of CuO nanoparticles were deposited onto their surfaces to improve their cycling performances. It is found that the CuO coated sample has the capacity retention higher than 90% at the rates below 30 C after 10 cycles, which also has the highest capacities of 135 and 123 mAh g(-1) at 40 C (5480 mA g(-1)) and 50 C (6850 mA g(-1)), respectively. The cyclic voltammograms result reveals that the CuO coating reduces the polarization and improves the electrochemical activity of cathode. In addition, experimental results indicate that CuO coating plays an important role in reducing the charge transfer resistance of the cell during cycling, which has been demonstrated by the electrochemistry impedance spectroscopy analysis. The above data indicate the potential application of CuO coated LiCoO2 in high power field. (C) 2011 Elsevier Ltd. All rights reserved.