Solid Oxide Fuel Cell Development by Using Novel Plasma Spray Techniques

Two plasma spray techniques have been developed to produce membrane-type solid oxide fuel cell (SOFC) units with the advantages of consecutive integrated cell fabrication, high efficiency, good cost effectiveness and microstructure tailoring capability. The atmospheric plasma spray (APS) and solution precursor plasma spray (SPPS) processes have demonstrated their capabilities to produce dense electrolyte layers as well as porous electrode layers that are designed particularly for intermediate temperature SOFCs. With a universal plasma spray system, the integrated fabrication of a dense La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte, a porous La0.8Sr0.2MnO3 cathode and a porous Ni+yttrium stabilized zirconia anode was produced using an optimal APS route. SPPS process has demonstrated more flexibility in materials, microstructures, porosities and overall thickness, and has been used successfully to produce a thin 40mol%La2O3-doped CeO2 (LDC40) interlayer (∼5μm) and a high-porosity Ni+LDC40 anode layer, respectively. In this work we will present the deposition of a variety of electrolyte and electrode layers applied by air plasma spraying or solution precursor plasma spraying. The merits of the two techniques, microstructures of the electrolyte and electrode layers, and performances of the single SOFC units have been evaluated and summarized.