Segmentation of PEM fuel cell catalyst layer via electrospray deposition

• A segmented catalyst layer with varying I/C ratios was developed using electrospray deposition. • SEM showed a more pronounced 3D structure in regions with a higher I/C ratio of 1.55. • The segmented layer outperformed the best conventional one, increasing power by 5.3% at 100% RH. • EIS analysis revealed reduced diffusion and charge transfer resistance in the segmented layer. The reaction rate distribution in the catalyst layer of a proton exchange membrane fuel cell is inherently non-uniform. Optimizing this non-uniformity in catalyst layer design is crucial for enhancing cell performance. This study developed a segmented catalyst layer with varying ionomer-to-carbon (I/C) ratios near the channel and land regions of the gas flow path using electrospray deposition. The segmented catalyst layer exhibited higher output power density than a conventional uniform catalyst layer with I/C ratios of 0.60, 1.00, and 1.55. Performance improvements were analyzed by fitting electrochemical impedance spectroscopy spectra to an equivalent circuit model. The results indicated that the segmented catalyst layer reduced diffusion and charge transfer resistance while increasing ionic resistance.