Ultrasonic spot welds of carbon paper and proton - exchange-membrane for applications in membrane-electrode-assemblies of fuel cells

Ultrasonic welding of carbon paper and proton exchange membrane (PEM) for membrane exchange assemblies (MEAs) of fuel cells (FCs) is a viable technology to replace hot-pressing, which may be time consuming and energy inefficient. Ultrasonic spot welding of carbon paper and PEM is investigated in order to understand the bonding mechanisms and obtain the suitable processing parameters. Micrographs of the tested specimens are examined to evaluate the welding quality. Effects of the welding time on the quality of the ultrasonic welds of the MEAs are studied. It is found that joints made by ultrasonic welding has the strength comparable to that of the base material. Values of welding time, holding time and downward force for successful bonding in terms of mechanical strength are obtained.