Details
| Original language | English |
|---|---|
| Pages (from-to) | 8436-8442 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry C |
| Volume | 120 |
| Issue number | 16 |
| Early online date | 14 Apr 2016 |
| Publication status | Published - 28 Apr 2016 |
Abstract
The local structure and mobility of lithium ions of the NASICON-type ionic conductor Li1+xAlxTi2-x(PO4)3 (with x = 0.0, 0.1, 0.2, 0.35, 0.5, 0.7 and 1.0), synthesized using conventional solid-state reaction route have been studied with solid-state nuclear magnetic resonance (NMR) techniques. 6Li, 7Li, 27Al, and 31P solid-state NMR experiments have been employed to trace the structural changes with varying cation concentration. The structural evolution and the creation of new Al and P environments with changing cation contents were studied by magic-angle spinning (MAS) NMR measurements. 6Li MAS NMR and 27Al triple-quantum MAS (3QMAS) show high-resolution spectra enabling site assignments and phase-purity inspections. The temperature dependences of 7Li NMR spin-lattice relaxation (SLR) rates for different compositions yield important information on the lithium ion mobility in the systems. Li ion jump rates, the activation energies, and the dimensionality of Li diffusion were deduced from the SLR experiments. A vacancy migration model has been proposed for the Li+ ionic diffusion process in pure-phase Li1+xAlxTi2-x(PO4)3 prepared by solid-state reaction. Above a certain threshold value of x (0.5) additional phosphate phases appear that slows down diffusion. This phenomenon can be observed from 6Li exchange spectroscopy. The optimum cation concentration for maximum ionic mobility in the phase-pure Li1+xAlxTi2-x(PO4)3 system can be read directly from the solid-state NMR results.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Chemistry(all)
- Physical and Theoretical Chemistry
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Journal of Physical Chemistry C, Vol. 120, No. 16, 28.04.2016, p. 8436-8442.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Solid-State NMR Investigations on the Structure and Dynamics of the Ionic Conductor Li1+xAlxTi2-x(PO4)3 (0.0 ≤ x ≤ 1.0)
AU - Vinod Chandran, C.
AU - Pristat, Sylke
AU - Witt, Elena
AU - Tietz, Frank
AU - Heitjans, Paul
N1 - We are grateful for the financial support by ‘Graduiertenkolleg Energiespeicher und Elektromobilität Niedersachsen (GEENI)’ and DFG Research Unit 1277 ‘Mobilität von Lithium-Ionen in Festkörpern (molife)’.
PY - 2016/4/28
Y1 - 2016/4/28
N2 - The local structure and mobility of lithium ions of the NASICON-type ionic conductor Li1+xAlxTi2-x(PO4)3 (with x = 0.0, 0.1, 0.2, 0.35, 0.5, 0.7 and 1.0), synthesized using conventional solid-state reaction route have been studied with solid-state nuclear magnetic resonance (NMR) techniques. 6Li, 7Li, 27Al, and 31P solid-state NMR experiments have been employed to trace the structural changes with varying cation concentration. The structural evolution and the creation of new Al and P environments with changing cation contents were studied by magic-angle spinning (MAS) NMR measurements. 6Li MAS NMR and 27Al triple-quantum MAS (3QMAS) show high-resolution spectra enabling site assignments and phase-purity inspections. The temperature dependences of 7Li NMR spin-lattice relaxation (SLR) rates for different compositions yield important information on the lithium ion mobility in the systems. Li ion jump rates, the activation energies, and the dimensionality of Li diffusion were deduced from the SLR experiments. A vacancy migration model has been proposed for the Li+ ionic diffusion process in pure-phase Li1+xAlxTi2-x(PO4)3 prepared by solid-state reaction. Above a certain threshold value of x (0.5) additional phosphate phases appear that slows down diffusion. This phenomenon can be observed from 6Li exchange spectroscopy. The optimum cation concentration for maximum ionic mobility in the phase-pure Li1+xAlxTi2-x(PO4)3 system can be read directly from the solid-state NMR results.
AB - The local structure and mobility of lithium ions of the NASICON-type ionic conductor Li1+xAlxTi2-x(PO4)3 (with x = 0.0, 0.1, 0.2, 0.35, 0.5, 0.7 and 1.0), synthesized using conventional solid-state reaction route have been studied with solid-state nuclear magnetic resonance (NMR) techniques. 6Li, 7Li, 27Al, and 31P solid-state NMR experiments have been employed to trace the structural changes with varying cation concentration. The structural evolution and the creation of new Al and P environments with changing cation contents were studied by magic-angle spinning (MAS) NMR measurements. 6Li MAS NMR and 27Al triple-quantum MAS (3QMAS) show high-resolution spectra enabling site assignments and phase-purity inspections. The temperature dependences of 7Li NMR spin-lattice relaxation (SLR) rates for different compositions yield important information on the lithium ion mobility in the systems. Li ion jump rates, the activation energies, and the dimensionality of Li diffusion were deduced from the SLR experiments. A vacancy migration model has been proposed for the Li+ ionic diffusion process in pure-phase Li1+xAlxTi2-x(PO4)3 prepared by solid-state reaction. Above a certain threshold value of x (0.5) additional phosphate phases appear that slows down diffusion. This phenomenon can be observed from 6Li exchange spectroscopy. The optimum cation concentration for maximum ionic mobility in the phase-pure Li1+xAlxTi2-x(PO4)3 system can be read directly from the solid-state NMR results.
UR - http://www.scopus.com/inward/record.url?scp=84966364900&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.6b00318
DO - 10.1021/acs.jpcc.6b00318
M3 - Article
AN - SCOPUS:84966364900
VL - 120
SP - 8436
EP - 8442
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 16
ER -