M. Inaba et al., STM study of well-defined graphite/electrolyte interface polarized in propylene carbonate solution containing 12-crown-4, ELECTROCH, 67(12), 1999, pp. 1153-1155
Surface morphology change of highly oriented pyrolytic graphite was investi
gated in 1 M (M = mol dm(-3)) LiClO4 dissolved in propylene carbonate (PC)
and PC+0.5 M 12-crown-4 using electrochemical scanning tunneling microscopy
to elucidate the mechanism of passive film formation on graphite electrode
in rechargeable lithium batteries. In PC, vigorous exfoliation of graphite
layers was observed after potential cycling dawn to 0 V vs. Li/Li+. Such e
xfoliation was greatly suppressed by 12-crown-4 addition. The original step
structure was nearly maintained, but swellings of graphite surface appeare
d after potential cycling. From these results, the role of 12-crown-4 in pa
ssive film formation was discussed.