Pore Structure and Cell Performance Analysis of PEMFC Catalyst Layers Fabricated by Decal Transfer Method with Variation of Hot Pressing Pressure

摘要

In proton exchange membrane fuel cells (PEMFCs), catalyst layers (CLs) are one of the most important components to achieve both high performance and cost reduction. Synthesizing CLs and catalyst coated membranes (CCMs) has been gathering much attention for optimization to satisfy these demands. In this study, we focused on hot pressing process and investigated effects of its pressure on the structure of the CLs. Performance evaluation, cross-sectional visualization and N_2 physisorption experiment of CCMs were performed. According to increasing the pressure up to 2 MPa, the cell performance was improved because of the enhancement of ionomer and carbon network in low humidification condition. On the other hand, drastic voltage drop appeared when the hot pressing pressure was over 2 MPa, because of decrease of the porosity and the pore size in the catalyst layer.