Structure and Electrochemical Properties of LiCo_(0.3)Ni_(0.7)O_2 Prepared by the Rheological Phase and Spray Drying Method

The cathode materials LiCo_(0.3)Ni_(0.7)O_2 were prepared from Co_(0.3)Ni_(0.7)(OH)_2 and LiOH· H_2O dispersed in the organic solution by the rheological phase and spray drying method in air at different sintering temperature for 16h.The TG-DTA analysis, XRD analysis, SEM and elec- trochemical tests were used to study the physical and the electrochemical performances of the materials. The results indicate that molecular level completely mixing of the raw materials of samples made by our method makes the sintering temperature drop to a lower temperature and the resulted sample has an excellent layered structure and the cation mixing and nonstoichiometric products are effectively restrained when sintered at 700℃.The material(sintered at 700℃) cycled between 2.80～4.25V shows a high initial capacity of 172mAh/g with an efficiency of 90.8% and its irreversible capacity only 16mAh/g. 91% of the initial discharge capacity remains after 40 cycles.