Experimental evaluation of the effect of humidification on the performaance of PEM fuel cell stack

Humidification of proton exchange membrane fuel cells (PEMFC) is needed to prevent the electrolyte from drying out, and prevents the flow of protons through the electrolyte and membranes. Humidifying either electrodes or both is expected to affect the performance enhancement of these cells. In order to establish this effect, an experimental study is conducted on a four-cell stack with an active cell area of 140 cm² and a built-in, membrane humidifier on the cathode side to analyze how humidifying just the cathode side of the stack varies from humidifying both the cathode and anode sides. A multi-station test bench and a humidification bottle are used to evaluate how varying the humidification on both electrodes affects the performance of the stack. Tests are conducted at various loads and a constant dew-point temperature first without the humidification bottle on the anode side, and then with the bottle to evaluate how humidification of both electrodes affects the fuel cell stack. Various polarization curves are established from the experimental data, and the relationship between different dew-point temperatures and humidifying both electrodes is determined graphically. The effect of varying current densities and corresponding voltages is also investigated from the experimental data.