Investigation of Cathode Microstructure for Highly Efficient Protonic Ceramic Fuel Cells

Abstract

Protonic ceramic fuel cells (PCFCs) are fascinating energy conversion systems at low operating temperatures (400-650 oC) due to their low activation energy for proton conduction. Despite these advantages, the efficient operation of the PCFC is still hindered, primarily due to the large polarization resistance of cathode. In order to overcome these large cathodic polarization resistance issues, the modification of cathode microstructure could be an effective way because the cathode microstructure of PCFC requires both sufficient pathways for oxygen supply and water vapor removal, along with a large electrochemically active area. In this paper, the correlation between the cathode microstructure and the electrochemical performance is investigated under the PCFC operating condition. Interestingly, the modification of cathode microstructure effectively decreases the cathodic polarization resistance from 0.077 to 0.048 Ω cm2 at 650 oC, and the corresponding maximum power density of PCFC is improved from 1.23 to 1.62 W cm- 2. These results indicate that the optimization of cathode microstructure is one of the crucial factors for the efficient operation of PCFC. These our findings could provide a useful guidance for effective development strategies of PCFC cathode material.