Microelectrode resistance measurement of PEFC catalyst inks with different ionomer ratio under drying process

Abstract

The high-frequency resistance of catalyst inks under the drying process to fabricate catalyst layer for polymer electrolyte fuel cells was measured by using a microelectrode chip. The catalyst inks with the different ionomer to carbon (I/C) ratio were measured. Surface observation by using a digital microscope was also conducted at the same time. The catalyst ink with I/C 0.6 showed larger resistance at the beginning of the drying than that with I/C 0.8 because proton concentration in the ink is low. I/C 0.6 also showed drastic resistance drop. This result indicates that I/C ratio affect the stability of the catalyst ink.