Electrochemical properties of helical carbon nanomaterials formed on LiCoO2 by chemical vapor deposition

We fabricated LiCoO2/carbon composites by forming helical carbon nanomaterials (HCNs) on the surface of LiCoO2 particles by chemical vapor deposition (CVD). The aim was to inhibit the degradation of the conductive path between the cathode active materials and carbon by mitigating the expansion of the electrode through cycling. We estimated the electrochemical properties of the composites as cathodes of rechargeable lithium cells. Using scanning electron microscopy measurements, we observed HCNs formed firmly on the surface of LiCoO2 particles. X-ray diffraction measurements indicated decomposition of LiCoO2, which was the main reason for the inferiority of the electrochemical properties. We found that the electrochemical properties of cells with the HCNs were not as good as those of cells with acetylene black (AB). Successful use of these composites requires inhibition of cathode active material decomposition and improvement of HCN conductivity. (C) 2009 Elsevier B.V. All rights reserved.