Yoshitaka Ono

The Analysis of Performance Loss with Low Platinum Loaded Cathode Catalyst Layers

An analysis of the performance loss with low platinum loaded cathode catalyst layers (CCLs) was conducted. A modified 1-D calculation model in the CCL was developed in this study, where newly developed oxygen transport resistance in the direction from pores in the CCL to platinum surface (RO2,CCL-micro) and the effect of platinum oxide coverage on RO2,CCL-micro were taken into account. As a result, the increased voltage loss with low platinum loaded CCLs was demonstrated by the modified 1-D calculation model. The analysis results indicated that the oxygen transport loss caused by RO2,CCL-micro became a dominant factor of the performance loss with the low platinum loaded CCLs.

Measurement of Gas Transport Characteristics in PEFC Electrolyte Membrane by Using Microprobes

Transport resistance of reactant gases in the membrane of polymer electrolyte fuel cells (PEFCs) was investigated by measuring the mass transport amount of gas species with microprobes inserted along the membrane thickness direction. The diffusion resistance inside the membrane and the interfacial transport resistance including dissolution resistance were separately evaluated by combining experiments and a theoretical model. It was found that diffusion resistance decreased with an increase in gas humidity and temperature. The measurement technique using the microprobe is a useful tool for understanding the gas transport phenomena in the membrane. The authors acknowledge fruitful discussions with Dr. Atsushi Ohma. Part of this work was supported by a Grant-in-Aid for Scientific Research from MEXT/JSPS.