Graphene nanosheets and palm-shell activated carbon in PEM fuel cell gas diffusion layers

Polymer Electrolyte Membrane (PEM) fuel cells represent a promising green energy technology that efficiently converts hydrogen and oxygen (or air) into clean electricity. In this study, graphene nanosheets (GNS) were explored as an advanced material for the gas diffusion layer (GDL) due to their exceptional electrical conductivity, thermal dissipation, water management capability, and catalytic activity. A series of GNS–AC composites was prepared and characterised to optimise GDL performance. The AC (3:2 indicates the impregnation ratios between the PKS carbon powder weight and activated agent) composite exhibited an electrical conductivity of 4.46 × 10⁻⁴ S/cm and a surface area of 26.643 m²/g, while pure GNS achieved superior properties with 4.20 × 10¹ S/cm conductivity and 486.283 m²/g surface area. The optimised hybrid composite containing 90% GNS and 10% AC (3:2) demonstrated the highest power output of 0.0013 W under hydrogen and air flow rates of 0.5 L/min and 1 L/min, respectively (denoted as 05H1A). The continuous adsorption of GNS–AC from the higher porosity, electric conductivity determined the power of the fuel cell. These results confirm that the 90%GNS + 10%AC (3:2) composite is a highly effective GDL material for PEM fuel cells, offering enhanced performance with optimised gas flow conditions.