Performance enhancement of hydrogen PEM fuel cell using graphene coated graphite electrodes

The experimental tests were carried out on a hydrogen proton exchange membrane fuel cell (PEMFC) to analyze its performance with graphene (25% by weight) coated on the surface of the graphite electrodes. The results are compared with the neat graphite electrodes. A single cell with 25 cm2 active area, 63.63% porosity for graphite, 40% platinum mixed with carbon by weight, Nafion 117 membrane, graphite monopolar plate, and current collector with copper was developed. The crystalline structure of the graphene is confirmed using Raman Spectroscopy which indicates the graphene coated electrodes has higher electrical conductance. The improved connected network of graphene with catalyst and electrodes leads to better charge transfer. The cell voltage increased significantly from 0.85 with graphite electrodes to 1.0 V with graphene-coated electrodes due to mainly a decrease in ohmic losses. Peak power density with graphene-coated electrodes (79.2 mW/cm2) is significantly improved compared with base graphite (53 mW/cm2) due to higher intrinsic mobility and lesser cracks. The contact angle with the graphene-coated is 147o indicating the hydrophobic nature of the electrode. The ohmic losses were reduced by 20.93%. The results indicate the efficiency and power density of a hydrogen PEM fuel cell could significantly be improved using partially coated graphene electrodes.