Ultra-low Pt loading for proton exchange membrane fuel cells by catalyst coating technique with ultrasonic spray coating machine

This paper reports use of an ultrasonic spray for producing ultra-low Pt load membrane electrode assemblies (MEAs) with the catalyst coated membrane (CCM) fabrication technique. Anode Pt loading optimization and rough cathode Pt loading were investigated in the first stage of this research. Accurate cathode Pt coating with catalyst ink using the ultrasonic spray method was investigated in the second stage. It was found that 0.272 mgPt/cm2 showed the best observed performance for a 33 wt% Nafion CCM when it was ultrasonically spray coated with SGL 24BC, a Sigracet manufactured gas diffusion layer (GDL). Two different loadings (0.232 and 0.155 mgPt/cm2) exposed to 600 mA/cm2 showed cathode power mass densities of 1.69 and 2.36 W/mgPt, respectively. This paper presents impressive cathode mass power density and high fuel cell performance using air as the oxidant and operated at ambient pressure.