固相合成锰酸锂的反应动力学研究

Study on reaction kinetics of LiMn₂O₄ synthesized by solid state reaction

摘要: 采用动态多重扫描速率法,测试了Li₂CO₃和MnO₂混合物在四个不同升温速率下的DSC曲线,结合TG分析,认为合成LiMn₂O₄的固相反应分四个阶段进行。用微分法中的K issinger法与积分法中的Ozawa法分别计算合成过程中各个反应阶段的活化能,其平均值分别为:620.5,341.1,426.1,450.6kJ.mol-1,结果表明:反应开始时,部分Li₂CO₃的催化分解反应最难发生。

Abstract: Based on a non-isothermal multiple scan method,the four DSC curves of Li₂CO₃/MnO₂ were tested at different heating rates.With analysis of TG,it is considered that the process to synthesize LiMn₂O₄ is composed of four segments.The activation energies corresponding to each segment are deduced by Kissinger and Ozawa methods,which are 620.5,341.1,426.1,450.6kJ·mol^-1,respectively.The result shows that the catalyzed decomposition of Li₂CO₃ is the most difficult reaction in synthesized process.