THERMAL-TREATMENT OF CO/LI2CO3 MIXTURES AT 1200-DEGREES-C

The phase evolution and the sintering process of Co/Li2CO3 mixtures following thermal treatment at 1200 degrees C in air were evaluated. In the dynamic step of the thermal treatment, Co3O4 and LiCoO2 were obtained and the densification and grain size of lithiated samples were higher than those of pure Co. In the isothermal step at 1200 degrees C, decomposition of LiCoO2, and diffusion of lithium ions into CoO with formation of LixCo1-xO solid solution were denoted, and after 40 h of isothermal treatment almost all LiCoO2 decomposed. The sintering constant n varied from 0.27 to 0.37, which suggested that grain-boundary diffusion was the primary mechanism for material transport. For all the compositions considerable morphological changes took place during thermal treatment.