Microwave synthesis of LiCoO2 cathode materials
(1. School of Science, Northeastern University, Shenyang 110004, China;
2. School of Materials and Metallurgy, Northeastern University,
Shenyang 110004, China)
2. School of Materials and Metallurgy, Northeastern University,
Shenyang 110004, China)
Abstract: LiCoO2 powder used as cathode material for lithium ion battery was synthesized by microwave heating with Co3O4 and LiOH•H2O as starting materials. The selection of output power and heating time of microwave can markedly affect the purity, morphology and electrochemical behaviors of the samples. X-ray diffraction (XRD) patterns display that the samples synthesized at 360W for 10min are pure layered LiCoO2, and SEM photos show that the powders are crystalline with well-defined facets whose sizes are about 5μm. The performance of Co3O4 and starting materials by microwave heating and conventional heating was investigated. It is indicated that Co3O4 decomposes into CoO in microwave field at 750℃ and the mechanism of preparing LiCoO2 by microwave heating is different from that by conventional heating. The electrochemical behaviors of samples were tested. As a result, the highest specific discharge capacity is 134.3mAh/g and the coulomb efficiency is 92.56%.
Key words: microwave synthesis; lithium-cobalt-oxygen compound; cathode materials; lithium ion battery