KF熔盐中钾插入石墨层间的电化学研究(英文)

Electrochemical investigation on kinetics of potassium intercalating into graphite in KF melt

通过循环伏安法和计时安培法对1163K温度下钾与石墨在KF熔盐中的插层反应动力学进行研究。循环伏安研究结果表明钾与石墨在KF熔盐中的插层/脱嵌反应包括动力学因素。用可逆及准可逆理论对计时安培曲线进行分析,进一步确认钾插入石墨层间这一过程是由钾离子在石墨中的扩散和相变动力学共同控制的。用准可逆动力学方程对电流-时间瞬态曲线进行非线性拟合,求得插层反应的传递系数为0.364。通过扫描电镜对发生钾插层反应后的石墨表面进行分析,发现石墨基体被严重腐蚀。

The kinetics of potassium intercalating into graphite in molten KF at 1 163 K was investigated by means of cyclic voltammetry and chronoamperometry.Cyclic voltammetry results indicate that intercalaltion/deintercalation of potassium into/from graphite involve kinetic limitations.The intercalation process of potassium was further confirmed to be governed by both the diffusion of potassium ion in graphite bulk and the phase transition kinetics through the analyses of current-time transient curves with reversible and quasi-reversible equations.The transfer coefficient of the intercalation reaction was calculated to be 0.364 according to the parameters resulting from nonlinear fitting of the current-time transient curves with a quasi-reversible equation.Analysis with scanning electron microscope shows that graphite matrix was severely eroded by intercalation of potassium.