锂金属与室温熔盐相互作用的电化学和SEM研究

STUDY ON THE INTERACTION BETWEEN LITHIUN AND AMBIENT MOLTEN SALT BY ELECTROCHEMICAL METHODS AND SEM

用电化学交流阻抗、循环伏安法和扫描电镜方法研究了锂和１－甲－３－乙咪唑氯化物／ＡｌＣｌ３室温熔盐体系的相互作用．结果表明，锂与该室温熔盐体系发生快的化学反应，生成两种钝化膜．它们有很高的电阻率，且不能保护锂不再受到侵蚀．在阳极极化时，锂的表面生成稳定的阳极钝化膜．电极表面的化学钝化膜和阳极钝化膜都使锂的电沉积－溶出过程变得很不可逆．因此，如果仅用１－甲－３－乙咪唑氯化物／ＡｌＣｌ３室温熔盐体系做为高能电池的非水电解质，不论是在一次电池中还是在二次电池中。

The interaction between lithium and the ambient molten salt, 1-methyl-3-ethylimidazolium chloride/AlCl 3 system, has been studied using electrochemical impedance, cyclic voltammetry and scanning electron microscope. It is indicated that lithium reacts rapidly with the melt and two kinds of passitive film are formed on the lithium surface. Their conductivity is very low, but they can not protect the lithium from corrosion by the melt. Upon anodic polarisation stable anodic passitive films are formed on the surface of lithium. Both chemical and anodic passitive films cause that the plating-stripping process of the lithium is extremely irreversible. Thus, if the surface of the lithium is not modified by another chemical, it can be directly used into above melen salt system as a negtive electrode neither in the primary battery nor in the secondary battery.