Effect of ca+2 addition on the properties of ce0.8gd0.2o2-δ for it-sofc

[摘要] This paper reports the effect of Ca2+addition on the structural and electrical properties of Ce0.8Gd0.2O2-δ(GDC) electrolyte for low temperature solid oxide fuel cell application. The Ca (0, 0.5, 1 and 2 mol %) doped GDC solid electrolytes have been prepared by solid state method. The sintered densities of the samples are greater than 95%. XRD study reveals the cubic fluorite structure. The microstructure of the samples sintered at 1400°C resulted into grain sizes in the range of 1.72 to 10.20 μm. Raman spectra show the presence of GDC single phase. AC impedance analysis is used to measure the ionic conductivity of the electrolyte. Among all the compositions, the highest conductivity is observed in the GDC sample with 0.5 mol% Ca addition. Nyquist plots resulted in multiple redoxation process such as grain and grain boundary conductions to final conductivity. Estimated blocking factor is lower for the GDC electrolyte with 0.5mol% Ca, indicating that Ca addition was promoted grain boundary conduction. Activation energies were calculated from Arrhenius plot and are found in the range of 1eV.

[发布机构] Department of Physics, Institute of Aeronautical Engineering College, Dundigal, Hyderabad; Telangana, India^1;Center for Ceramic Processing, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad; AP; 500005, India^2;Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India^3;Department of Physics, St. Mary's Engineering College, Deshmukhi; R.R (DT), India^4;Department of Physics, Anurag Engineering College, Hyderabad; Telangana, India^5

[效力级别] 机械制造

[关键词] AC impedance analysis;Fluorite structure;GDC Electrolyte;Grain-boundary conductions;Low temperature solid oxide fuel cells;Sintered density;Solid state method;Structural and electrical properties