首页|Novel synthesis of stabilized Bi1-x-yGdxDyyO1.5 solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells(SOFCs)

Novel synthesis of stabilized Bi1-x-yGdxDyyO1.5 solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells(SOFCs)

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Herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi2O3 solid electrolyte system via solid-state processing under atmospheric conditions.Doping with Dy3+and Gd3+has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi2O3-type polymorphs.The synthesized ceramics were characterized using X-ray diffraction(XRD),field emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEM-EDX),thermal gravimetry/differential thermal analysis(TG/DTA),and the four-point probe technique(4PPT).XRD analysis reveals that the samples Bi1-x-yGdxDyyO1.5(y=0.05/x=0.05,0.10,0.15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20)exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic structure.The XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic(FCC)structure with a space group of Fm-3m.FESEM micrographs reveal that the composition Bi0.90Gd0.05Dy0.05O1.5 has no significant holes.Nevertheless,an evident increase in the pore formation is observed as the amount of Gd2O3 increases until it reaches 20%.This finding suggests that dense pellets are formed during the sintering process at 900-1000 ℃.The DTA analyses were performed to verify the phase stability,which agrees with the XRD results.The electrochemical performance of the synthesized Dy-Gd co-doped Bi2O3 solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy(EIS)technique.Based on EIS and conductivity measurements,Bi0.75Gd0.20Dy0.05O1.5 ex-hibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 S/cm at 627 ℃ compared to the other samples;this composition can be used as a solid electrolyte for intermediate-temperature solid oxide fuel cells(SOFCs).

Solid oxide fuel cells(SOFCs)Rare earthsSolid-state processingRietveldFast Fourier transform(FFT)Electrochemical impedance spectroscopy(EIS)

Ahmed H.Ibrahim、Yehia M.Abbas、H.A.Ayoub、Marwa H.Ali、Mustafa Aldoori

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Materials Science Laboratory,Physics Department,Faculty of Science,Suez Canal University,41522,Ismailia,Egypt

Ministry of Higher Education and Scientific Research,Aliraqia University,10011,Baghdad,Iraq

2024

稀土学报(英文版)
中国稀土学会

稀土学报(英文版)

CSTPCDEI
影响因子:1.3
ISSN:1002-0721
年,卷(期):2024.42(10)