Ionic conductivity and structure of (LiCl)[sub 2]-Al[sub 2]O[sub 3]-SiO[sub 2] xerogels

Journal Article · · Chemistry of Materials; (United States)

OSTI ID:6458501

Wang, B; Szu, S; Greenblatt, M; Klein, L C ^[1]

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1. State Univ. of New Jersey, Piscataway, NJ (United States)

(LiCl)[sub 2]-Al[sub 2]O[sub 3]-SiO[sub 2] xerogels were prepared by a sol-gel process. The structure of the heat-treated xerogels was studied by powder X-ray diffraction, Fourier transform infrared spectroscopy, and [sup 7]Li, [sup 29]Si, and [sup 27]Al nuclear magnetic resonance techniques. [sup 7]Li NMR studies indicate two kinds of lithium ions in the xerogels: (a) polycrystalline LiCl dispersed in the pores of the xerogel and (b) lithium ions associated with nonbridging oxygens on the silica tetrahedra or associated with AlO[sub 4][sup [minus]] units. For the samples having the same lithium content (20 mol % (LiCl)[sub 2]) the ionic conductivity increases with increasing Al[sub 2]O[sub 3]/SiO[sub 2] ratio. This is attributed to the increasing concentration of lithium ions associated with tetrahedral AlO[sub 4] or nonbridging oxygens in the xerogel. A constant activation energy is observed when the (LiCl)[sub 2] content increases from 10 to 20 mol % for samples having the sample Al[sub 2]O[sub 3]/SiO[sub 2] ratio of 1/2. This constant activation energy is analyzed in terms of the competition between the decreasing jump distance tending to decrease activation energy and increasing Coulombic interaction tending to increase activation energy. 29 refs., 10 figs., 3 tabs.

• OSTI ID: 6458501
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 4:1; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ABSORPTION SPECTROSCOPY
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
COLLOIDS
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY
GELS
HALIDES
HALOGEN COMPOUNDS
IONIC CONDUCTIVITY
LITHIUM CHLORIDES
LITHIUM COMPOUNDS
LITHIUM HALIDES
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RESONANCE
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS