High performances of ultrafine and layered LiCoO 2 powders for lithium batteries by a novel sol–gel process

Abstract

LiCoO 2 powders are rapidly becoming important cathode materials in commercial lithium-ion batteries because of their excellent properties. In the present work, LiCoO 2 powders were prepared using a novel sol–gel method with citric acid as a chelating agent, hydroxypropyl cellulose as a dispersant agent and LiNO 3, Co(NO 3) 2·6H 2O as starting materials. The effects of calcination temperature and the calcination time on the structure and morphology of LiCoO 2 powders were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. According to the analysis, the crystallinity of LiCoO 2 powders depends on the calcination temperature and calcination time. The results indicate the layered, pure and ultrafine HT-LiCoO 2 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.