Investigation of the catalyst ink compositions for a uniform microporous catalyst layer preparation via electrospray deposition technique and MEA assembling conditions in PEMFC specific

Abstract

High utilization of catalyst and preserving evenly distributed pores for Proton Exchange Membrane Fuel Cell (PEMFC) electrodes were optimized using an in-house designed electrospray system. In order to hold the porous electrode structure prepared through the electrospray technique by varying ink compositions. Using optimized electrodes and commercially available Nafion-212 membrane, a series of membrane-electrode assemblies (MEAs) were fabricated by varying the hot-pressing parameters of pressure, temperature, and time for evaluating the performance at 60 °C to 80 °C with varying relative humidity. The MEAs were hot-pressed at 8 MPa for 390 s at a temperature of 150 °C generating a maximum peak power density of 903 mW cm−2 and current density of 1040 mA cm−2 at 0.6 V and calculated electrochemical surface area (ECSA) is 23.96 m2/gPt. In contrast, the MEAs hot-pressed for the same length of time at the same temperature but with a lower pressure of 2.67 MPa generated higher peak power density of 1130 mW cm−2, higher current density of 1320 mA cm−2 at 0.6 V, despite having a lower ECSA of 19.18 m2/gPt. Overall, results in this study present that low hot-pressing pressure and a high pressing temperature enable a negative effect on the porous structure of electrospray electrodes for producing the high achievement of MEA performance.