Optimizing The Hot-Press Procedure Of High-Temperature Proton Exchange Membrane Fuel Cells For Adhesion Strength And Conductivity

High-temperature proton exchange membrane (HT-PEM) fuel cell systems are under active development for a variety of mobile and stationary power applications. Measurements of membrane-electrode assembly (MEA) thickness, impedance, and adhesion strength were obtained for samples fabricated over ranges of conditions to optimize for the most suitable processing parameters. Testing quantified the effects of hot-press time, temperature, and pressure, over ranges of 1-10 minutes, 140 – 200oC, and 7.72 – 92.67 MPa, respectively. After hot pressing, MEA samples were tested for resistance with a Solartron impedance analyzer, and for adhesion strength with a Scott internal bond tester. From these results, optimal hot-press parameters were established and four 25 cm2 MEAs were fabricated and tested. Post-pressing analysis of MEAs was conducted using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Our results demonstrate that the optimal conditions for MEA hot-pressing for the HT-PEM system are around 170oC and 23.1 MPa for 5 minutes.