Design and development of gas diffusion layers with pore forming agent for proton exchange membrane fuel cells at various relative humidity conditions

Membrane electrode assemblies are developed by incorporating gas diffusion layers (GDL) to improve the lower and higher relative humidity performance of proton exchange membrane fuel cells (PEMFCs). In the present study, gas diffusion layer samples containing microporous layers, are fabricated using carbon paper substrate, PUREBLACK (R) carbon powder and polyethylene glycol as pore forming agent. The GDLs are studied in single cell fuel cell, to evaluate the effect of porosity of the micro-porous layer on the performance at different operating relative humidity conditions and compared with commercial GDLs. Scanning electron microscopy and contact angle measurements indicate crack-free surface morphology and hydrophobic characteristics of the PUREBLACK (R) based GDLs, respectively. By varying the wt. % of PEG, fuel cell performance is evaluated under relative humidity conditions of 60 and 100% using H-2/O-2 and H-2/Air at 70 degrees C and the durability is also evaluated for the GDL samples without and with 30% PEG. The fuel cell performance of the GDL with 30% pore forming agent (with a pore volume of 1.72 cc.g(-1)) exhibited higher performance (444 and 432 mW cm(-2) at 60 and 100% RH conditions, respectively using H-2 and air) compared to that without pore forming agent (436 and 397 mW cm(-2)). (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Membrane electrode assemblies are improved by incorporating gas diffusion layers with microporous layers to enhance the performance of proton exchange membrane fuel cells under different humidity conditions. The fabricated GDL samples with PUREBLACK (R) showed crack-free surface morphology and hydrophobic characteristics. The fuel cell performance was evaluated under different relative humidity conditions, with the GDL containing 30% pore forming agent showing higher performance compared to those without.