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

LiCoO 2 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 LiCoO 2 in high power field.