Effect of GDC infiltration on electrochemical performance of micro-tubular solid oxide fuel cells

In this thesis, the effect of GDC infiltration in the anode and cathode electrodes of the SOFCs produced in microtubular design on the electrochemical performance is investigated. In addition, optimization studies are carried out for the parameters such as holding time, sintering temperature, number of infiltration steps and loading amount. According to the electrochemical performance and impedance results, it is observed that there is a significant improvement in the performance of GDC infiltrated cells. This improvement is achieved by infiltrating nano sized GDC particles into porous electrodes, increasing the active triple phase boundaries due to forming additional ionic and electronic conduction paths. While the maximum power density of a standard cell without infiltration procedure at an operating temperature of 800 °C is 252,7 mW/cm2, after the optimization studies, the maximum power density of 2,19 mg/cm2 GDC infiltrated cell is found to be 523,0 mW/cm2, almost doubling the performance. Thus, with this thesis, it is shown that it is possible to fabricate high-performance microtubular SOFCs by infiltrating nano-sized mixed conductor GDC particles.