The effective catalyst layer structure fabricated by screen printing method for high performance proton exchange membrane fuel cell (PEMFC)

Abstract

Catalyst and perfluorosulfonated ionomer are used to fabricate catalyst layer(CL) for carrying protons from electrode to perfluorosufonic acid membrane efficiently in PEMFC. The combination of catalyst and ionomer forms microstructures, which influence the electrochemical performance of PEMFC. These microstructures may also vary with the types of coating methods. Catalyst utilization is also affected by the change of microstructures such as porosity and morphology. Therefore, two methods of catalyst coating, which are screen printing and spraying, have been studied. Due to the different distribution of ionomer and catalyst, two different kinds of morphology were obtained using screen printing and spraying method respectively. The microstructure in screen printing method led to the high catalyst utilization without varying the content of perfluorosulfonated ionomer and catalysts. Moreover, this method enhanced electrochemical performance of the PEMFC at high current density.