On the oxide ion conductivity of potassium doped strontium silicates

Abstract

07.10.14 KB. Ok to add accepted version to spiral, subject to 12 month embarg

Amorphous Na2Si2O5 as a fast Na+ conductor: an ab initio molecular dynamics simulation

“…[1][2][3] Recently, a new family of oxides bearing a generic formula of Sr 1Àx A x SiO 3À0.5x (A ¼ Na, K) has been reported and immediately garnered much attention due to its high ionic conductivity, e.g. [8][9][10][11][12][13] These studies presented compelling evidence that the material was virtually a two-phase mixture, for example, consisting of a SrSiO 3 phase and an amorphous Na 2 Si 2 O 5 phase for the Sr 1Àx Na x SiO 3À0.5x system. [8][9][10][11][12][13] These studies presented compelling evidence that the material was virtually a two-phase mixture, for example, consisting of a SrSiO 3 phase and an amorphous Na 2 Si 2 O 5 phase for the Sr 1Àx Na x SiO 3À0.5x system.…”

“…0.01 S cm À1 at 500 C. [4][5][6][7] The report quickly drew criticisms from groups that conducted follow up research. [9][10][11][12][13] The SrSiO 3 phase was an electrical insulator while the amorphous Na 2 Si 2 O 5 phase was a good ionic conductor. [9][10][11][12][13] The SrSiO 3 phase was an electrical insulator while the amorphous Na 2 Si 2 O 5 phase was a good ionic conductor.…”

On the cause of conductivity degradation in sodium strontium silicate ionic conductor

“…1,2 Singh et al originally postulated from hightemperature neutron diffraction data that the oxygen vacancies were created through Sr-site doping by Na and became mobile at a temperature 4400 1C, thus leading to oxide-ion conduction. [5][6][7][8][9] A critical work by Bayliss et al showed from an experimental and theoretical perspective that substitution of Na or K into Sr sites is an energetically unfavourable process. [5][6][7][8][9] A critical work by Bayliss et al showed from an experimental and theoretical perspective that substitution of Na or K into Sr sites is an energetically unfavourable process.…”

On Sr1–xNaxSiO3–0.5x New Superior Fast Ion Conductors

“…In addition, sub-micron elemental mapping revealed a chemical inhomogeneity of the sample. 7 Our work has focussed on a systematic study of Na-doped SrSiO 3 materials (nominally Sr 1−x Na x SiO 3−0.5x , x=0; 0.1; 0.2; 0.3; 0.4) by a combination of laboratory powder X-ray diffraction (PXRD), variable temperature powder neutron diffraction (PND), impedance measurements, SEM, 29 Si solid state NMR and the quantification of amorphous content by Rietveld analysis. We conclude that x ≤ 0.4 samples contain significant amorphous material and far lower Na content than believed to-date.…”