3D Printing of Functional Layers for Solid Oxide Fuel Cells and Electrolysers
One prerequisite is the development of stable dispersions (‘inks’) of sub-micrometre sized metal oxide particles (i.e. (ZrO2)0.92(Y2O3)0.08, NiO, La1-xSrxMnO3-δ) in liquid phases with suitable solids fractions and physical properties, for which results will be presented (Fig.1a). These inks have been used to print the functional layers of SOFCs/SOEs (Fig.1b). However, geometries of electrode | electrolyte structures are subject to limitations imposed by the requirement to minimise the spatial distributions of potential and current densities. Hence, results will also be presented for predictions (Fig.2) of those parameters, modelled using finite element software, and preliminary current density-potential difference data for a printed SOE.
Firstly, yttria-stabilized zirconia (YSZ) particles were deposited onto a planar YSZ | NiO substrate, as pre-cursors to a thin (ca. 10 µm), gas-tight electrolyte, formed by heating the green structure to ca. 500°C to burn out organics used to stabilise ink particles against aggregation, followed by sintering YSZ at ca. 1400°C. Subsequently, YSZ and NiO nanoparticles were co-printed with an organic polymer to fabricate porous electrode structures on non-porous YSZ electrolyte layers.
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