Zy. Deng et al., INFRARED PHOTOTHERMAL DEFLECTION SPECTROSCOPY - A NEW PROBE FOR THE INVESTIGATION OF ELECTROCHEMICAL INTERFACES, Journal of the Electrochemical Society, 143(5), 1996, pp. 1514-1521
An infrared photothermal deflection spectroscopy system has been devel
oped using infrared tunable diode lasers in the wavelength region from
8 to 16 mu m. This system allows the collection of in situ optical ab
sorption spectra of species at electrode/electrolyte interfaces in an
electrochemical cell. The infrared spectra of LiOH and Li2CO3 formed o
n the surface of a lithium foil were recorded. The infrared phototherm
al deflection spectroscopy technique has been used to monitor the lith
ium electrode surface in an operating cell, Li/P(EO)(2)LiN(CF3O2)(2)/N
i. The in situ spectra (in the 800-1000 cm(-1) region) show that the f
ilm formation at Li/polymer electrolyte interfaces is dominated by LiO
H, although there also appears to be organic species in the surface fi
lm.