Enhancing fuel cell performance via laser-induced ablation of gas diffusion nonwoven carbon paper with reduced contact resistance

초록

Reducing the electrical resistance of the gas diffusion layer (GDL) is a key factor in improving the performance proton exchange membrane fuel cells (PEMFCs), as it facilitates electron transport by lowering contact resistance. In this study, a laser ablating process was employed to selectively decompose the electrically insulating fluoropolymer layer present on the surface of the gas diffusion nonwoven carbon paper (GDNCP), one of components of the GDL, thereby effectively reducing its contact resistance. Through parametric study, the ablating process was optimized. As a result, the area-specific resistance (ASR) of untreated GDNCP was measured to be 10.96 m Omega cm2 at 1 MPa, whereas the laser-ablated GDNCP exhibited a 38 % reduction, reaching 6.74 cm2. To reduce the contact resistance, laser treatment was applied to the entire surface of the GDNCP. GDNCP treated on the MPL-contacting side exhibited maximum current densities of 1160 mA/cm2 at 50 relative humidity and 1180 mA/cm2 at 100 % relative humidity, corresponding to increases of approximately % and 36 %, respectively, compared to the untreated GDL. These results confirm that the laser ablating process effectively enhances the power performance of fuel cells under both humidity conditions by reducing the contact resistance of GDL.

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