Composition of Surface Layers on Li Electrodes in PC, LiClO4 of Very Low Water Content

Surface layers formed on Li in PC, with less than 1 ppm of water have been analyzed by use of IR spectroscopy, SIMS, ESCA, low angle x‐ray diffraction, and SEM. Electrodeposited Li showed a highly porous micromorphology with surface layers containing primarily a partially chlorinated hydrocarbon polymer and lithium carbonate. The carbonate is mostly present in the inner film regions, the polymer in the outer. Perchlorate decomposes to chlorine compounds of lower valences, with higher‐valent chlorine found in the outer film regions and lower‐valent in the inner.