Development of Novel SOFC's Comprising Thin-Film Nanostructured Electrolyte Layers

Abstract

This paper reports a study on the preparation of thin nano-structured 8YSZ membrane films, which can be sintered to full density at a lower temperature (~ 1200{degree sign}C) than currently applied in SOFC manufacturing (> 1400{degree sign}C). For the deposition process, four different coating liquids with varying particle size, covering the range from 85 nm to 6 nm, were prepared. In the first part, it is demonstrated that nano-dispersions with a particle size of e.g. 85 or 60 nm can be used for the formation of dense YSZ membranes with a thickness of 1 - 2 µm on a regular macroporous SOFC anode, but the layers can only be sintered to full density at 1400{degree sign}C. In the second part, ultra-thin YSZ membranes are prepared by sol-gel coating (particle size 35 and 6 nm). These layers show a thickness < 500 nm and a very tight mesoporous or microporous structure in the calcined state (pore size < 5 nm), which allows a sintering treatment in the desired temperature range (~ 1200{degree sign}C).