Development of electrode structure and analysis of electrode pore distributions in phosphoric acid fuel cells

By changing the electrode fabrication method, the performance of an electrode was improved. Inside electrodes fabricated by a conventional method, inactive catalysts exist owing to catalysts covered by polytetrafluoroethylene (PTFE). To reduce these inactive catalysts and to develop an electrode structure, we tried to change the procedures of mixing the materials. To begin with, we manufactured PTFE/C powder and Pt/C powder, respectively. We fabricated electrodes by mixing the PTFE/C powder and the Pt/C powder. The performance of these electrodes was superior to that of electrodes fabricated by the conventional method. We also analyzed how the distributions of small pores and large pores had an effect upon the performance of the electrode. The optimal composition of PTFE was determined, and the rate of small pores and large pores was quantitatively analyzed by a porosimeter.