| Solid oxide fuel cell(SOFC) is a kind of independent power-generating devices, which transfer the chemical energy of fuels directly into clean electricity. Electrophoretic deposition(EPD) is a traditional but effective technique to fabricate thin or thick ceramic films upon a variety of conductive substrates. In the EPD process, the electrodes(or substrates) are immersed into a ceramic suspension within which the ceramic particles are charged and well dispersed. If we apply an electric field between the two electrodes, particles will move in one direction and be deposited on the substrates.In this work, electrophoretic deposition(EPD) of double-particle Al2O3 films on Ni/YSZ substrate was performed using ethanol as solvent with some amounts of hydrochloric acid(HCl) as the dispersant under direct current(DC) and alternating current(AC) fields. Those compact films with rough surface can be served as solid electrolyte in the SOFC. Film thickness was varied by adjusting the voltage and deposition time. Surface and cross section morphology were observed using scanning electron microscopy(SEM) and image analysis software.The results showed that the samples of similar thickness have higher grain density when coated using AC as compared to DC-EPD. AC-EPD method is advantageous for economic fabrication of thin, dense and gas tight electrolyte film for solid oxide fuel cells(SOFC) applications. In the single cell test, we found that the SOFC made by AC-EPD has a higher open-circus voltage and maximum power density. |
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