Medžiagotyra (May 2019)

The Influences of Sio2 on the Sintering Behavior and the Properties of Na+- Β/Β"-Al2O3 Solid Electrolyte

  • Sung-Tae LEE,
  • Dae-Han LEE,
  • Sung-Ki LIM

DOI
https://doi.org/10.5755/j01.ms.25.3.14246
Journal volume & issue
Vol. 25, no. 3
pp. 328 – 334

Abstract

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SiO2-doped Na+-β/β″-Al2O3 was synthesized via a solid-state reaction, and the relationship between the SiO2 content and properties of Na+-β/β″-Al2O3 was investigated. Respective specimens were doped with 0 – 5 wt.% SiO2 as a liquid phase sintering promotor and sintered. The specimens were characterized by XRD, SEM, densimeter and impedance analyzer. In the sintered samples, the phase fraction of β″-Al2O3 decreased as the SiO2 content increased, whereas the relative sintered density was enhanced with the inclusion of less than 0.7 wt.% SiO2. The relative sintered density of Na+- β/β″-Al2O3 sintered specimen with 0.7 wt.% SiO2 doping reached 99.2 % of the theoretical density and the sintered density decreased when the amount of SiO2 was larger than 1 wt.% result from excessive liquid-phase formation during sintering. Similarly, the ionic conductivity of SiO2-doped Na+-β/β″-Al2O3 was enhanced by doping with a small amount of SiO2, whereas the addition of more than 1 wt.% SiO2 negatively affected the ionic conductivity of Na+-β/β″-Al2O3 due to a decrease in the sintered density and unfavorable phase relationship. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.14246

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