Elaboration of Porous NiO/8YSZ Layers by Several SPS and SPPS Routes

Solution Precursor Plasma Spraying (SPPS) is a thermal spray process where a feedstock solution is heated and pyrolized to form fine (i.e., a parts per thousand(a)1000 nm) molten particles that deposit onto a substrate to form a layer. The benefits of implementing the SPPS process include, among others: (i) the possibility to create unique microstructures at nanometer scale without the injection feeding problems usually associated to powder feeders and delivery cables and (ii) rapid exploration of novel precursor compositions. In this study, preparation and characterization of porous anode layers with homogeneous Nickel distribution and nanometer sized microstructure are considered for solid oxide fuel cell (SOFC) application. Once the solution is injected, the droplets go through several chemical and physical changes and impact the substrate in different states, from fully molten one to unpyrolized one. The effects of some spray parameters, such as the spray distance and the plasma flow mass enthalpy, on the layer architecture and composition were investigated. The results show that dense or porous layers can be manufactured depending on the operating parameters.