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doi:10.1016/0167-2738(91)90185-E   



A carbon-13 and lithium-6 nuclear magnetic resonance study of lithium perchlorate/poly (ethylene oxide) electrolytes


John F. O'Garaa, Gholamabbas Nazrib and Donald M. MacArthurb

aAnalytical Chemistry Department, General Motors Research Laboratories, Warren, MI 48090-9055, USA

bPhysical Chemistry Department, General Motors Research Laboratories, Warren, MI 48090-9055, USA


Received 13 December 1990;  accepted 22 February 1991.  Available online 13 September 2002.

Abstract
13C and 6Li high-resolution solid-state NMR techniques are used to characterize the morphology and dynamics of LiClO4/ poly(ethylene oxide) )(PEO) electrolytes. 13C spectra and relaxation are sensitive to the polymer morphology and the local chain motions. The 6Li magic-angle spinning (MAS) NMR technique offers a detailed quantitative structural picture of the lithium atoms. At low concentrations of LiClO4 in PEO, where the conductivity rises with increasing concentration, the number of dissociated lithium ions is apparently the determining factor. At higher concentrations the observed drop in conductivity is associated with an increase in ion-ion interactions as well as decreased ion mobilities due to a lack of available sites on the polymer and due to decreasing polymer chain mobility. The number of dissociated lithium ions therefore is less important at these concentration.

Solid State Ionics,Volume 47, Issues 1-2, August 1991, Pages 87-96

title: A carbon-13 and lithium-6 nuclear magnetic resonance study of lithium perchlorate/poly (ethylene oxide) electrolytes
author;John F. O'Garaa, Gholamabbas Nazrib and Donald M. MacArthur

Abstract
13C and 6Li high-resolution solid-state NMR techniques are used to characterize the morphology and dynamics of LiClO4/ poly(ethylene oxide) )(PEO) electrolytes. 13C spectra and relaxation are sensitive to the polymer morphology and the local chain motions. The 6Li magic-angle spinning (MAS) NMR technique offers a detailed quantitative structural picture of the lithium atoms. At low concentrations of LiClO4 in PEO, where the conductivity rises with increasing concentration, the number of dissociated lithium ions is apparently the determining factor. At higher concentrations the observed drop in conductivity is associated with an increase in ion-ion interactions as well as decreased ion mobilities due to a lack of available sites on the polymer and due to decreasing polymer chain mobility. The number of dissociated lithium ions therefore is less important at these concentration.

Solid State Ionics,Volume 11, Issue 1, September 1983, Pages 91-95
title:Microscopic investigation of ionic conductivity in alkali metal salts-poly(ethylene oxide) adducts
author: C. Berthiera, W. Goreckia, M. Miniera, M.B. Armandb, J.M. Chabagnob and P. Rigaudb

Abstract
We present conductivity, N.M.R. and D.S.C. measurements in two P(EO) complexes : P(EO) 8LiCF3SO3 and P(EO) 10NaI. From N.M.R. experiments, we deduce the respective amount of crystalline and elastomeric phases at all temperatures, as well as the salt concentration in these various phases. The elastomeric phase is shown to be responsible of the ionic conductivity at all temperatures, and to be very dilute (n  25 just above the pure P(EO) melting point. The high melting salt-rich complexes are found surstoechiometric (n  3.5). The various factors affecting the temperature dependence of the conductivity are discussed, as well as the kinetics problems.

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