Fabrication of a light-weight SOFC using ceramic fibre paper as substrate

Sammanfattning: A novel method for the fabrication of a light-weight solid oxide fuel cell (SOFC) has been evaluated at Catator. This was conducted in order to lower the weight and thus cost of an unmanned aerial vehicle. The main aim for this thesis was to achieve a thin, dense and crack-free electrolyte using a ceramic fibre paper as substrate. This paper was impregnated with colloidal solutions and pressed to planar and tubular structures to achieve a porous substrate for the SOFC. Nickel was incorporated and a bilayer was coated on top of the substrate to create a flat surface onto which a thin electrolyte and cathode layer could be applied. All steps were followed by heat treatments to enable drying, calcination or sintering processes. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to investigate the characteristics of the electrolyte and the chemical make-up of the SOFC respectively. Optical microscopy was used extensively to get an understanding of how the different experimental methods were affecting the microstructure. A system test was performed by constructing a test oven but failed due to malfunctions which was probably caused by short circuits. The results from the SEM indicates that the electrolyte was quite dense but not free from cracks and the EDS shows an unevenly distributed anode. If the desired outcome is to be achieved using similar methods an automated process need to be implemented since it is currently too time consuming to be cost effective. A weight decrease of 50 % was observed compared to a conventional SOFC previously used by Catator, so if a working method could be achieved there could be decreases in cost for mobile applications.