Understanding the defect chemistry of alkali metal strontium silicate solid solutions: insights from experiment and theory

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

“…5,6 A subsequent oxygen isotope exchange and SIMS measurement on the Sr 0.8 K 0.2 Si 0.5 Ge 0.5 O 2.9 sample indicated a very low oxygenion diffusivity. 8,9 Among these mechanistic studies on ionic conduction, Bayliss et al 6 first reported the conductivity degradation phenomenon in a Sr 1Àx Na x SiO 3À0.5x (x = 0.45) sample although the causes for the degradation were not specifically discussed in the paper. It was also found that the conductivity increased with the amount of amorphous phase Na 2 Si 2 O 5 present in the sample, which was also proportional to the Na-content.…”

“…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.…”

Microstructure and electrical properties of Sr1 − x Na x SiO3 − x/2 ceramics prepared by SPS process

“…In addition, the electrical conductivities and the phase compositions of SNS were relatively stable in the working temperatures and reducing atmospheres for a long time [11]. Their further researches showed that the electrical mechanism of SNS was mainly oxygen ion conduction, not proton conduction [12,13].…”