Thermal dynamics on synthesis of Li₂MnSiO₄ cathode materials

Li₂MnSiO₄ cathode materials were synthesized by high temperature solid-state reaction. The synthesis process was investigated by thermogravimetric-differential scanning calorimetry (TG-DSC). The results show that there are two main mass loss stages due to the dehydration and thermal decomposition of raw materials. There are five endothermic peaks appeared in DSC curves obtained at different heating rates. According to the thermal analysis, the apparent activate energy of three endothermic peaks (>200°C) is calculated to be 384.12, 120.63, 263.43 kJ/mol and 350.78, 117.16, 227.59 kJ/mol using the Doyle-Ozawa method and the Kissinger method, respectively. In the Kissinger method, the corresponding reaction order, frequency factor and reaction rate equation are further inferred. The results of X-ray diffraction (XRD) show the step-sintering method proposed from the thermal dynamics results can be used to produce better optimized-Li₂MnSiO₄.