Fabrication of high precision PEFC membrane electrode assemblies

Membrane electrode assemblies (MEAs) for polymer electrolyte fuel cells (PEFCs) are commonly prepared in the research laboratory by hand painting liquid catalyst material onto Teflon supports, then transferring the dried catalyst to a membrane separator by hot pressing. This hand application of the catalyst is a time consuming process of modest precision with respect to catalyst loading, producing samples not ideally suited for controlled experimentation. We report the results of a method for preparing MEA catalyst layers in a faster and highly reproducible fashion. This method relies on catalyst inks that have been modified to increase their coating reproducibility, and the use of a support material that improves the hot press transfer of the catalyst to the membrane separator. The result is a process which is not only significantly more precise and faster than hand painting, but which produces cells with nearly 25% higher current density in the critical voltage operating region.