Effect of catalyst ink particle size on the structure of the catalyst layer and electrical performance in the process of ultrasonic spray manufacturing PEMFCs

Abstract

Proton exchange membrane fuel cells (PEMFCs) have the advantage of high energy conversion efficiency. This study introduces a novel strategy aimed at enhancing the performance of fuel cells through the optimization of process parameters pertaining to the ultrasonic spraying of catalyst layers. This study found that with an increase in flow rate or a decrease in pressure, the atomization particle size of the catalyst ink enlarges, broadening the size distribution simultaneously. Larger ink droplets falling on the Nafion membrane result in a greater concentration of particles building up within the coffee ring, leading to deformities like orange peel texture, protrusions, and grooves within the catalyst layer. Consequently, the polarization curve deteriorates, and Pmax (peak power density) diminishes. Research has shown that optimizing the process parameters of ultrasonic spraying can optimize the catalyst layer structure, improve the mass transfer performance of membrane electrode assemblies (MEAs), and is an effective new solution for improving MEAs performance.