Preparation and Characterization of a Novel Composite Electrolyte Ceria-Sulfate for Intermediate Temperature Solid Oxide Fuel Cells

Authors

Ze TONG
Yi-mei YIN
Jie-wei YIN
Zi-feng MA

Corresponding Author

Zi-feng MA(zfma@sjtu.edu.cn)

Abstract

A novel composite electrolyte SDC-(Li/Na)₂SO₄ was prepared for intermediate temperature solid oxide fuel cells (ITSOFC). The phase structure and cross-sectional morphology were examined by XRD and SEM, respectively, and the ionic conductivity was investigated by AC impedance in a temperature range of 400 ^oC ~ 700 ^oC in air. It was found that the composite electrolyte was composed of two phases: crystal SDC and amorphous (Li/Na)₂SO₄. The conductivity of the composite electrolyte was significantly larger than that of SDC at intermediate temperatures (550 ^oC ~ 700 ^oC) and increased with temperature in three stages: 1) T<500 ^oC, the apparent activation energy of ionic transport was 1.28 eV; 2) In the range of 500 ^oC ～ 550 ^oC, the ionic conductivity rapidly increased due to the melting of sulfate; 3) T>550 ^oC, the conductivity slowly raised with temperature, the activation energy decreased significantly to 0.30 eV, and the values of the conductivity of SDC-(Li/Na)₂SO₄ were notabily higher than those of SDC and previously reported SDC-(Li/Na)₂CO₃. For example, the conductivity of SDC-(Li/Na)₂SO₄ was 0.217 S·cm^-1 at 550 ^oC, which was 25 times higher than that of SDC and 3.2 times higher than that of SDC-(Li/Na)₂CO₃. The results indicate that the ionic conducting mechanism changes in composite electrolyte due to the melting of the sulfate second phase, and the diffusion and transmission of ions are accelerated.

Keywords

composite electrolyte, solid oxide fuel cells, samaria doped ceria, conductivity

DOI Link

https://doi.org/10.61558/2993-074X.2951

Publication Date

2013-06-28

Online Available Date

2012-12-23

Revised Date

2012-12-18

Received Date

2012-10-12

Recommended Citation

Ze TONG, Yi-mei YIN, Jie-wei YIN, Zi-feng MA. Preparation and Characterization of a Novel Composite Electrolyte Ceria-Sulfate for Intermediate Temperature Solid Oxide Fuel Cells[J]. Journal of Electrochemistry, 2013 , 19(3): Article 4.
DOI: 10.61558/2993-074X.2951
Available at: https://jelectrochem.xmu.edu.cn/journal/vol19/iss3/4

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