Abstract
LixTiO2-B nanowires (0 < x ≤ 0.9) are considered to act as promising anode materials in secondary Li-ion batteries. Li self-diffusion parameters in mixed conducting nanowires of the composition Li0.3TiO2 are directly determined by mixing time (t(m))-dependent two-time Li-7 spin-alignment echo (SAE) nuclear-magnetic-resonance (NMR) correlation spectroscopy between 330 and 500 K. SAE NMR reveals extremely slow Li self-diffusion processes in LixTiO2-B. Li jump rates tau(-1) range from 5 to 2.5x10(3) s(-1). The corresponding hopping correlation functions F-2 can be well parametrized with stretched exponentials, F-2 proportional to exp[-(t/t(m))(gamma)], with an exponent gamma=0.35(2) being independent of temperature. The influence of spin-diffusion effects on the echo amplitude is elaborated by evolution time-dependent Li-7 SAE-NMR experiments. The results are compared with those obtained by conventional Li-7 NMR spin-lattice relaxation measurements.
Original language | English |
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Number of pages | 8 |
Journal | Physical Review. B, Condensed matter and materials physics |
Volume | 80 |
Issue number | 6 |
DOIs | |
Publication status | Published - Aug 2009 |
Keywords
- anodes
- boron
- diffusion
- lithium
- mixed conductivity
- nanowires
- nuclear magnetic resonance
- secondary cells
- spin echo (NMR)
- spin-lattice relaxation
- titanium compounds
- ECHO NMR-SPECTROSCOPY
- RECHARGEABLE LITHIUM BATTERIES
- NUCLEAR-MAGNETIC-RESONANCE
- SOLID-STATE NMR
- SPIN-ALIGNMENT
- ION CONDUCTORS
- MOTION
- DYNAMICS
- GLASSES
- STORAGE