AN ELECTROCHEMICAL STUDY OF THE REACTIVITY AT THE LITHIUM ELECTROLYTEBARE LITHIUM METAL INTERFACE .2. UNPURIFIED SOLVENTS

The in situ cutting method to expose bare lithium metal, the corrosion potential-time transients, and voltammetric measurements have been em ployed to study the behavior of lithium in various organic electrolyte environments. In situ optical and ex situ scanning electron microscop y techniques were used to examine the morphology of Li electrode surfa ces, during exposure at open circuit and after anodic polarization. Th e following electrolytes have been investigated: LiAsF6, LiPF6, LiBF4, LiClO4, and Li(CF3SO2)2N in unpurified THF and PC. Small amounts of w ater shift the corrosion potential towards more positive values (compa red to purified electrolytes). During intensive anodic cycling with Li AsF6/THF the presence of water leads to the breakdown of a surface fil m and exposure to bare lithium metal.