Optimal feedstock composition to control the porosity in solid oxide fuel cell produced by additive manufacturing

Nowadays, the research of alternatives power resources has a huge importance in the society to develop new and eco-friendly systems to reduce the climate change. One good and studied option is the solid oxide fuel cells (SOFC), however, with the conventional shapes produced by using traditional processing routes, these systems present low efficiency. Within this context, one way to improve it is creating a high specific surface, and this can be achieved by means of the additive manufacturing (AM) technique. During the last decade, the AM has been the manufacturing technique of the future, thanks of the advantages that it provides; being one of the most important advantages the ability to print complex geometries like honeycomb among others. The purpose of this final Master’s project is the combination of these two fields, following the work developed by myself during my Bachelor’s project and some posterior work. In this case the idea is focused the project on the optimization of the resolution of the SOFC. As well as try to obtain the best feedstock composition to achieve the optimal porosity for each part. In addition, through this Master’s project, a continuity on this AM field implemented within the CIEFMA group (Centre for Structural Integrity and Reliability of Materials) of the Department of Materials Science and Engineering (CEM) UPC's , can be assured, opening new applications of AM combined with the energy field. To carry out this study, the used materials were: 8Y-TZP for the electrolyte, Lanthanum gallate strontium and magnesium doped for the cathode and gadolinium oxide for the anode. This study was divided in three parts; the first one consisted in an evaluation of the particle size, by using the laser diffraction particle size technique (also known as Mastersizer) and some scanning electron microscopy micrographs, with a step to process the powder and modify the size. In a second phase the best composition was search trying different ink compositions. The main rheological parameters for the optimal ceramic pastes (G’, G’’) will be studied. As a final step a cylindrical sample was printed by robocasting. Afterwards, the microstructural (e.g. density, phases, etc.) and micromechanical properties (e.g. hardness, elastic modulus, fracture mechanisms, etc.) will be determined by using advanced characterization techniques, like field emission scanning electron microscopy, focused ion beam, nanoindentation among others, to assure a minimal mechanical integrity of SOFC parts