Designing Cathode Layers for PEFC with the Low Platinum-Loading

For the further spread of PEFC technology, reduction of Pt-loading in PEFC has been targeted in order to reduce the cost. First, MEAs with various Pt-loading and carbon loading were made and evaluated using a standard 46.5%Pt/ KB (TEC10E50E). The correlation between Pt-loading and activation overvoltage, and the correlation between carbon loading and concentration overvoltage were investigated. Consequently, the minimum requirement of platinum was found to 0.15 - 0.20 mgPt/cm(2), and the optimum carbon loading was found to 0.46 mgC/cm(2) in our experimental conditions. Furthermore, the methods to increase CL thickness without increasing Pt-loading were considered, and then importance of homogeneous platinum dispersion in CL has been realized.