Stability of LiAlO2 as electrolyte matrix for molten carbonate fuel cells

et al. 2017

This article reports on Li self-diffusion in lithium containing metal oxide compounds. Case studies on LiNbO 3 , Li 3 NbO 4 , LiTaO 3 , LiAlO 2 , and LiGaO 2 are presented. The focus is on slow diffusion processes on the nanometer scale investigated by macroscopic tracer methods (secondary ion mass spectrometry, neutron reflectometry) and microscopic methods (nuclear magnetic resonance spectroscopy, conductivity spectroscopy) in comparison. Special focus is on the influence of structural disorder on diffusion.

Section: Lithium Aluminatementioning

confidence: 99%

Slow Lithium Transport in Metal Oxides on the Nanoscale

Uhlendorf

Ruprecht

et al. 2017

“…In nuclear technology, it is of interest as blanket material for preparing tritium fuel for nuclear fusion [1,8,9]. Finally, this material is also under discussion as additive in polymer electrolytes [10,11], as inert electrolyte support material in molten carbonate fuel cells [12,13], and as coating material for electrodes in Li-ion batteries [14].…”

Section: Introductionmentioning

confidence: 99%

Lithium Diffusion in Ion-Beam Sputtered Amorphous LiAlO₂

Rahn

Heitjans³

et al. 2015

Abstract:We investigated lithium self-diffusion in amorphous lithium aluminate (LiAlO 2 ) layers between room temperature and 473 K. For the experiments, amorphous 6 LiAlO 2 (30 nm)/ 7 LiAlO 2 (1200 nm) isotope hetero-structures were deposited by ion-beam sputtering on sapphire substrates. Diffusion profiles were analysed by secondary ion mass spectrometry (SIMS). The results show that the diffusivities obey the Arrhenius law with an activation enthalpy of (0.94±0.02) eV. This is not much different to the activation enthalpy of 1.14 eV found for LiAlO 2 single crystals by impedance spectroscopy. It rationalizes the only modest enhancement of diffusivities in amorphous lithium aluminate compared to single crystals of three to five orders of magnitude in the temperature range studied, when compared with, e.g., lithium niobate.

“…The main reason for this large interest is the attractive application possibility of these materials as ion conductors in the field of energy storage. Fast ionic motion is preferred in battery electrolytes [7] whereas the electrolyte additives are designed to have extremely slow ionic diffusion [8][9][10] for stability reasons. Small Li diffusivity is important also for some industrial applications such as in semiconductor manufacture [11] and in fusion reactors [12].…”

Section: Introductionmentioning

confidence: 99%

NMR and Impedance Spectroscopy Studies on Lithium Ion Diffusion in Microcrystallineγ-LiAlO₂

Nakhal

Chandran

et al. 2015

Abstract:In this work nuclear magnetic resonance (NMR) and impedance spectroscopy (IS) studies on Li ion dynamics in microcrystalline -LiAlO 2 are presented. The sample was prepared by solid state synthesis between Li 2 CO 3 and Al 2 O 3 in air, followed by a quenching procedure. The presence of phase-pureLiAlO 2 was confirmed by X-ray powder diffraction including Rietveld refinement.Further structural characterization was done with 6 Li, 7 Li and 27 Al NMR. Several NMR techniques such as spin-lattice relaxation measurements, motional narrowing experiments, as well as spin-alignment echo were employed for the investigation of Li ion diffusion. The measurements were carried out at high temperatures (up to 970 K) in order to access the regime of Li ion motion being very slow. The dc conductivities measured by IS in the temperature range from 680 K to 870 K were converted to diffusion coefficients being compatible with those obtained by NMR.