Influence of ionomer concentration and membrane thickness on membrane electrode assembly in alkaline fuel cell performance

Abstract

The alkaline fuel cell is subject to extensive research owing to its fast kinetic response relative to acidic media. However, the efficiency of the catalytic layer at the electrodes depends on the amount and distribution of ionomers present there. It is crucial to have the right ionomer concentration to have the best cell performance. Additionally, the membrane thickness is a significant parameter that affects the system performance in alkaline fuel cells. This research studies the best alkaline fuel cell performance using the membrane electrode assembly preparation parameters. The prepared membrane electrode assembly consists of catalyst layers containing Fumion, a commercial anion exchange ionomer, as a binding agent, sandwiched a Fumasep, a well-known commercial anion exchange membrane. This work elucidates the single-cell alkaline fuel cell performance by quantifying the influence of Fumion concentrations (~20–60 wt.%) within the catalytic layer and Fumasep thicknesses (30, 75 and 130 μm). The best concentration of Fumion was found to be 50 wt.%, culminating in the maximum peak power density of 67 mW cm⁻² achieved by the FAA-3-PK-75. Meanwhile, FAA-3-PK-130 exhibited the highest open-circuit potential with lowest power density at 53 mW cm⁻². These findings may serve as a valuable guide for membrane electrode assembly preparation in alkaline fuel cells.