Details
Original language | English |
---|---|
Pages (from-to) | 1303-1321 |
Number of pages | 19 |
Journal | Zeitschrift für Physikalische Chemie |
Volume | 231 |
Issue number | 7-8 |
Early online date | 9 Jun 2017 |
Publication status | Published - 26 Jul 2017 |
Abstract
In order to improve our understanding of the Li-mobility in oxide glass networks with Li as the principle mobile particle, electrical conductivity and self-diffusivity of lithium was studied in two phosphate (0.2 Li2O·0.8 P2O5, 0.3 Li2O·0.2 MgO·0.5 P2O5) and one borate (0.25 Li2O·0.75 B2O3) glass compositions. Conductivity measurements provided information about ion dynamics while isotope-exchange experiments involving isotopically enriched Li diffusion glass couples provided information about long-range diffusivity of Li-isotopes through borate and phosphate networks. Due to the limitations of individual glass stabilities, the temperature range for selected experiments was very small, e.g. as in the case of Li-phosphate composition between 373 and 520 K. The activation energy for Li-migration derived from conductivity measurements was similar for Li-Mg-phosphate and Li-borate, 90.4 and 85.2 kJ/mol, while for pure Li-phosphate the value was 74.7 kJ/mol. In the case of self-diffusion, the activation energies were comparable with Li-Mg-phosphate having the highest value of 76.9 kJ/mol while Li-phosphate and Li-borate had almost the same value of 72.9 and 72.2 kJ/mol, respectively. In these glass compositions with similar Li-cation concentration, the differences in the mobility predominantly depend on structural arrangement of building units and the spatial distribution of negative potentials, as reflected in the value of HR/f, i.e. the Haven ratio divided by the correlation factor, as a mean to better understand the diffusion mechanism in glass structures, where vacancy vs. interstitial diffusion cannot be clearly defined. For Li-phosphate almost unconstrained Li-migration was indicated with the HR/f value of 0.98, while Li-Mg-phosphate had the most structural constraint on mobilized Li-cations, with the HR/f value of 0.30. Findings are compared with silicate (Li2O·3 SiO2) and aluminosilicate (Li2O·Al2O3·4 SiO2) glasses from our previous studies in order to elaborate the effect of network topology.
Keywords
- conductivity, glass, lithium, mass spectroscopy, self-diffusion
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Zeitschrift für Physikalische Chemie, Vol. 231, No. 7-8, 26.07.2017, p. 1303-1321.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Lithium Mobility in Borate and Phosphate Glass Networks
AU - Welsch, Anna Maria
AU - Behrens, Harald
AU - Murawski, Dawid
AU - Horn, Ingo
N1 - Funding Information: The authors would like to express gratitude to Mareille Wittnebel, Franziska Fritsche, Florian Kiesel, Julian Feige from University of Hannover, Hannes Schlicht (Jena Optics) and Frank Korte (BGR, Hannover) for their valuable help in glass preparation and experimental work. Financial support by Deutsche Forschungsgemeinschaft through project FOR 1277 is gratefully acknowledged.
PY - 2017/7/26
Y1 - 2017/7/26
N2 - In order to improve our understanding of the Li-mobility in oxide glass networks with Li as the principle mobile particle, electrical conductivity and self-diffusivity of lithium was studied in two phosphate (0.2 Li2O·0.8 P2O5, 0.3 Li2O·0.2 MgO·0.5 P2O5) and one borate (0.25 Li2O·0.75 B2O3) glass compositions. Conductivity measurements provided information about ion dynamics while isotope-exchange experiments involving isotopically enriched Li diffusion glass couples provided information about long-range diffusivity of Li-isotopes through borate and phosphate networks. Due to the limitations of individual glass stabilities, the temperature range for selected experiments was very small, e.g. as in the case of Li-phosphate composition between 373 and 520 K. The activation energy for Li-migration derived from conductivity measurements was similar for Li-Mg-phosphate and Li-borate, 90.4 and 85.2 kJ/mol, while for pure Li-phosphate the value was 74.7 kJ/mol. In the case of self-diffusion, the activation energies were comparable with Li-Mg-phosphate having the highest value of 76.9 kJ/mol while Li-phosphate and Li-borate had almost the same value of 72.9 and 72.2 kJ/mol, respectively. In these glass compositions with similar Li-cation concentration, the differences in the mobility predominantly depend on structural arrangement of building units and the spatial distribution of negative potentials, as reflected in the value of HR/f, i.e. the Haven ratio divided by the correlation factor, as a mean to better understand the diffusion mechanism in glass structures, where vacancy vs. interstitial diffusion cannot be clearly defined. For Li-phosphate almost unconstrained Li-migration was indicated with the HR/f value of 0.98, while Li-Mg-phosphate had the most structural constraint on mobilized Li-cations, with the HR/f value of 0.30. Findings are compared with silicate (Li2O·3 SiO2) and aluminosilicate (Li2O·Al2O3·4 SiO2) glasses from our previous studies in order to elaborate the effect of network topology.
AB - In order to improve our understanding of the Li-mobility in oxide glass networks with Li as the principle mobile particle, electrical conductivity and self-diffusivity of lithium was studied in two phosphate (0.2 Li2O·0.8 P2O5, 0.3 Li2O·0.2 MgO·0.5 P2O5) and one borate (0.25 Li2O·0.75 B2O3) glass compositions. Conductivity measurements provided information about ion dynamics while isotope-exchange experiments involving isotopically enriched Li diffusion glass couples provided information about long-range diffusivity of Li-isotopes through borate and phosphate networks. Due to the limitations of individual glass stabilities, the temperature range for selected experiments was very small, e.g. as in the case of Li-phosphate composition between 373 and 520 K. The activation energy for Li-migration derived from conductivity measurements was similar for Li-Mg-phosphate and Li-borate, 90.4 and 85.2 kJ/mol, while for pure Li-phosphate the value was 74.7 kJ/mol. In the case of self-diffusion, the activation energies were comparable with Li-Mg-phosphate having the highest value of 76.9 kJ/mol while Li-phosphate and Li-borate had almost the same value of 72.9 and 72.2 kJ/mol, respectively. In these glass compositions with similar Li-cation concentration, the differences in the mobility predominantly depend on structural arrangement of building units and the spatial distribution of negative potentials, as reflected in the value of HR/f, i.e. the Haven ratio divided by the correlation factor, as a mean to better understand the diffusion mechanism in glass structures, where vacancy vs. interstitial diffusion cannot be clearly defined. For Li-phosphate almost unconstrained Li-migration was indicated with the HR/f value of 0.98, while Li-Mg-phosphate had the most structural constraint on mobilized Li-cations, with the HR/f value of 0.30. Findings are compared with silicate (Li2O·3 SiO2) and aluminosilicate (Li2O·Al2O3·4 SiO2) glasses from our previous studies in order to elaborate the effect of network topology.
KW - conductivity
KW - glass
KW - lithium
KW - mass spectroscopy
KW - self-diffusion
UR - http://www.scopus.com/inward/record.url?scp=85024906525&partnerID=8YFLogxK
U2 - 10.1515/zpch-2016-0927
DO - 10.1515/zpch-2016-0927
M3 - Article
AN - SCOPUS:85024906525
VL - 231
SP - 1303
EP - 1321
JO - Zeitschrift für Physikalische Chemie
JF - Zeitschrift für Physikalische Chemie
SN - 0942-9352
IS - 7-8
ER -