Gr. Zhuang et al., NOVEL IN-SITU AND EX-SITU TECHNIQUES FOR THE STUDY OF LITHIUM ELECTROLYTE INTERFACES, Journal of power sources, 54(1), 1995, pp. 20-27
Various aspects of the reactivity of lithium toward propylene carbonat
e (PC) and poly(ethylene oxide) (PEG) have been examined using ex situ
and in situ spectroscopic techniques, respectively. Temperature progr
ammed desorption of perdeuterated PC (d(6)-PC) layers condensed at abo
ut 150 K on a clean Li film supported on an Au foil yielded a broad ml
e peak, at temperatures in the range from 220 to 520 K (and thus much
lower than that found for Li2CO3), which was tentatively ascribed to t
he thermal decomposition of a lithium alkyl carbonate. A spectroelectr
ochemical cell/environment controlled chamber has been designed and co
nstructed to examine Li/PEO(LiClO4) electrolyte interfaces formed by L
i electrodeposition on to a thin Au layer sputtered on the surface of
a Ge internal reflection element in situ using attenuated total reflec
tion Fourier-transform infrared (ATR/FT-IR) spectroscopy. This assembl
y enables variable temperature measurements to be performed under cond
itions of utmost cleanliness. Preliminary results have indicated that
in the case of PEO/LiClO4 this ATR/FT-IR technique has sufficient sens
itivity to observe changes in the composition of the surface and near
surface region, including reaction products and perchlorate anions, wh
ich contribute to the transport of charge in the electrolyte phase.