氧气中嵌氧生成LiMn_2O_4的动力学

Formation Kinetics of LiMn_2O_4 through Oxygen Inserting in O_2

为了得到氧气中嵌氧生成LiMn2O4的动力学方程,用TG、XRD和H-E积分方程研究氧在其分解产物中的嵌入过程。1373～1243K的嵌氧反应为3LiMnO2+Mn3O4+(1-3δ/2)O2(g)3LiMn2O4-δ(Tetragonal)和LiMn2O4-δ(Tetragonal)+δ/2O2(g)LiMn2O4(Cubic),属生成核生长控制,活化能为-166 330kJ mol。1243～1146K的嵌氧反应为LiMn2O4-δ(Tetragonal)+δ/2O2(g)LiMn2O4(Cubic),属于成核生长控制,活化能为-140 357kJ mol。由H-E积分方程得到的动力学参数与、之间存在明显的动力学补偿效应。

In order to gain the formation kinetics of LiMn_2O_4 in O_2, a program is taken to study Oxygen inserting into the decomposition of LiMn_2O_4 during the cooling processes, where TG, XRD and H-E integrated equation is used. The oxygen intercalation reaction occurs in following steps: (1)3LiMnO_2+Mn_3O_4+(1-3δ/2)O_2(g)3LiMn_2O_4-δ(Tetragonal) and LiMn_2O_4-δ(Tetragonal)+δ/2O_2(g)LiMn_2O_4(Cubic) (1373K～1243K),and LiMn_2O_4-δ(Tetragonal)+O_2(g)LiMn_2O_4(Cubic) (1243K～1146K). The insertion process from 1373K to 1243K is controlled by nucleating and growing,and its activated energy is -166.330kJ·mol^(-1). Nucleating and growing is the key step for the reaction from 1243K to 1146K, its activated energy is -140.357kJ·mol^(-1). The kinetic compensative effects not only exist in Arrhenius equation, but also in Harcourt-Esson equation.