Synthesis and Characterization of Proton-conducting Electrolytes and Nano-fiber Anode Functional Layer for H+-SOFC Applications
| Autor: | Yu-Shuo Huang, 黃俞碩 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 This study reports the synthesis of proton-conducting Ba1-xSrxCe0.8-xZrxY0.2O3-δ (x =0, 0.2, 0.4) ceramics by using a combination of citrate-EDTA complexing sol-gel process and the composition-exchange method. Compared to the sintered oxides of similar composition prepared from conventional sol-gel powders,Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3-δoxides synthesized by sol-gel combined with the composition-exchange method are found to exhibit improved sinterability, higher conductivity, more homogeneous phase. Among all sintered oxides in this study, the Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3-δpellet fabricated by this new method has the highest conductivity, 0.017 S/cm at 800℃, which is higher than those pressed from conventional sol-gel powders. Based on the experimental results, we discuss the mechanism for improvement in these properties in terms of calcined particle characteristics. This work demonstrates thatBa0.8Sr0.2Ce0.6Zr0.2Y0.2O3-δoxides synthesized by sol-gel combined with the composition-exchange method would be a promising electrolyte for H+-SOFC applications. A SrCe0.8Y0.2O3-δ-NiO anode functional layer was added between the Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3-δelectrolyte and the Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3-δ-NiO anode substrate to investigate its effect on the performance of single cells. Anode-supported electrolyte fuel cells were fabricated and tested. The single cell without SrCe0.8Y0.2O3-δ-NiO anode functional layer generated maximum power densities of 201.08 mWcm−2 at 800 °C. Electrochemical impedance spectroscopy (EIS) measurements for three cells revealed that the addition of the anode functional layer reduced the contact resistance as well as the polarization resistance for the cell, resulting thus in the improved cell performance. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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