D. Golodnitsky et al., A new approach to the understanding of ion transport in semicrystalline polymer electrolytes, J ELEC CHEM, 491(1-2), 2000, pp. 203-210
Despite the conventional wisdom that ion transport in polymer electrolytes
is mediated primarily by polymer segmental motion, we have performed measur
ements on semicrystalline complexes of poly(ethylene oxide) (PEO) with LII
which suggest that transport occurs preferentially along the PEO helical ax
is, at least in the crystalline phase. The principal basis for this claim i
s an observed enhancement by a factor of 5-20 in electrical conductivity in
stretched polymer electrolyte films. The effect of uniaxial stress on the
polymer electrolyte long and short range structures was investigated by X-r
ay diffraction and Li-7 nuclear magnetic resonance (NMR) spectroscopy. Stre
tching results in partial alignment of the PEO helices and also induces sma
ll but observable changes in the Li+ solvation sheath. These results are co
rrelated with the ionic conductivity enhancement in the stretched polymer,
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