Bi2O3 and La10Si6O27 composite electrolyte for enhanced performance in solid oxide fuel cells

[摘要] Adding suitable metal oxide into lanthanum silicate apatite can produce a composite with a good oxygen ion-conducting electrolyte that enhances the performance of solid oxide fuel cells (SOFCs). In this paper we present the synthesis and characterisation of Bi2O3and La10Si6O27composite prepared by a solid state reaction. The sintering temperature of the composite was 1500°C for 10 hours with the heating and cooling rates of 10°C per minute. The properties of the resulting composite have been characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ionic conductivity measured by an a.c. impedance spectroscopy (IS). Rietveld refinement of XRD data shows that the composition is purely the mixture of Bi2O3and La10Si6O27with the unit cell parameters of the main phase as a = 9.9810 (8) and c = 7.3239 (6) Å. The room temperature crystal structure was hexagonal with space group P63/m. The highest ionic conductivity of 1.76 × 10-2Scm-1with a corresponding activation energy of 0.39 eV was obtained at 750°C. SEM images show the material is densed enough to use as an electrolyte for SOFCs.

[发布机构] Universiti Brunei Darussalam, Faculty of Integrated Technologies, Jalan Tungku Link, Gadong; BE 1410, Brunei^1;Universiti Brunei Darussalam, Centre for Advanced Material and Energy Sciences, Jalan Tungku Link, Gadong; BE 1410, Brunei^2

[效力级别] 工业技术

[关键词] A.c. impedance spectroscopy;Composite electrolytes;Heating and cooling rates;Ion conducting electrolytes;Lanthanum silicate apatite;Sintering temperatures;Solid oxide fuel cells (SOFCs);Unit cell parameters