The Study of Surface Films Formed on Lithium and Noble Metal Electrodes in Polar Aprotic Systems By the Use of In Situ Fourier Transform Infrared Spectroscopy

Two approaches for in situ Fourier transform infrared spectroscopy (FTIR) studies of surface films formed on lithium and noble metal electrodes at low potentials in polar aprotic systems ( e.g. alkyl carbonates, ethers, and their mixtures) are presented and discussed. One is based on external reflectance mode similar to SNIFTIRS. The other method is based on single internal reflectance mode (SIRFTIRS) with working electrodes of thin metal films deposited on crystals. Both methods were found to be adequate for the study of surface species formed on the active metals in several solvent systems in spite of the strong masking effect of the solution absorption. The advantage of these in situ techniques over the previously used ex situ measurements is demonstrated and discussed.