论文部分内容阅读
采用热重-差示扫描量热技术研究了高温固相法合成Li2MnSiO4正极材料的反应过程。结果表明:Li2MnSiO4前驱体在加热升温过程中的两个失重区主要归因于原料的脱水和分解;在不同升温速率条件下测得的差示扫描量热曲线主要由5个吸热峰组成;利用Doyle-Ozawa法和Kissinger法对前驱体分解失重阶段中三个吸热峰(>200℃)的反应活化能计算结果分别为:384.12、120.63、263.43 kJ/mol和350.78、117.16、227.59 kJ/mol;基于Kissinger法进一步确定了相关反应阶段的反应级数、频率因子和动力学速率方程。XRD测试说明:基于热力学结果的分步优化工艺能够减少终产物的杂质,改善合成质量。
The reaction process of Li2MnSiO4 cathode material synthesized by high temperature solid state reaction was studied by TG-DSC. The results show that the two weight loss zones of Li2MnSiO4 precursors during heating and heating process are mainly attributed to the dehydration and decomposition of raw materials. The differential scanning calorimetry curves of Li2MnSiO4 precursors at different heating rates mainly consist of five endothermic peaks. The calculated activation energies of the three endothermic peaks (> 200 ℃) by Doyle-Ozawa method and Kissinger method were 384.12, 120.63, 263.43 kJ / mol and 350.78, 117.16, 227.59 kJ / mol; based on the Kissinger method, the reaction order, frequency factor and kinetic rate equation of the relevant reaction stage were further confirmed. The XRD test shows that the stepwise optimization process based on the thermodynamic results can reduce the impurities in the final product and improve the quality of the synthesis.