AN ELECTROCHEMICAL STUDY OF THE REACTIVITY AT THE LITHIUM ELECTROLYTE BARE LITHIUM METAL INTERFACE .1. PURIFIED ELECTROLYTES

An in situ cutting technique has been developed to expose bare lithium metal in various organic electrolyte environments. Potentiodynamic polarization measurements reveal substantial shifts of the corrosion potential towards positive values and only a moderate increase of anodic dissolution for in situ cut lithium metal. Corrosion potential-time transients have been measured commencing at ca. 50 ms. The following electrolytes have been investigated: LiAsF6, LiBF4, LiClO4, and Li(CF3SO2)2N in THF, 2Me-THF, and PC. The transients permit the ranking of the reactivity of the electrolytes and show that passivating reactions are often ''completed'' in less than 1 s, even for very carefully purified electrolytes. These measurements shed light on our understanding of the stability of various salts and solvents in contact with lithium.