High performances of ultrafine and layered LiCoO₂ powders for lithium batteries by a novel sol-gel process

LiCoO₂ powders are rapidly becoming important cathode materials in commercial lithium-ion batteries because of their excellent properties. In the present work, LiCoO₂ powders were prepared using a novel sol-gel method with citric acid as a chelating agent, hydroxypropyl cellulose as a dispersant agent and LiNO₃, Co(NO₃)₂·6H₂O as starting materials. The effects of calcination temperature and the calcination time on the structure and morphology of LiCoO₂ powders were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. According to the analysis, the crystallinity of LiCoO₂ powders depends on the calcination temperature and calcination time. The results indicate the layered, pure and ultrafine HT-LiCoO₂ powders can be obtained at 700 °C for 4 h in air. After 25 cycles, the electrode demonstrates the charge/discharge capacities at 175 and 154 mAh/g, respectively, which will be suitable for high capacity cathode materials in rechargeable lithium-ion batteries.