Effects of ceramic based pastes on electrochemical performance of solid oxide fuel cells

Various commercially available anode and cathode materials are investigated as the anode and cathode contact paste, respectively, for solid oxide fuel cells. In order to obtain a printable paste, chosen materials are mixed with an organic vehicle and a thinner as well as a pore former. The effect of the contact materials on the cell performance is evaluated experimentally via cell performance measurements by installing a short stack. The pastes are brush painted on the corresponding interconnector and current collecting mesh. A short stack without any contact paste is also tested for comparison as a base case. The impedance and microstructural analyses are also performed through an impedance analyzer and a scanning electron microscope, respectively. The effects of solid loading for two anode and two cathode contact paste materials which provide the best two performances during the electrochemical performance tests are also studied. After optimizing the solid loading in the anode and cathode contact paste according to the performance results, the best contact materials for each side are decided. The final short stack is then installed by using the best combination of contact pastes and then tested. The final cell shows 0.39 W cm−2 and 0.90 W cm−2 peak power densities at 700 °C and 800 °C, respectively, whereas the base cell provides only 0.26 W cm−2 peak power density at 800 °C. The improvement in the cell performance is considered to be due to the enhanced contact and better current collecting by employing contact pastes.