Fast Activation of PEMFCs with Different Membrane Thicknesses via a Cathode Starvation Protocol Using a Single Potentiostat

Conventionally, PEMFCs have been activated using time- and hydrogen-consuming constant-potential (CP) protocols, which are costly to operate. More recent fast-activation approaches based on the cathode starvation (CS) method have been investigated using galvanostatic–potentiostatic programmed combination systems. Although the CS method is effective, it requires a complicated system. In this work, in contrast, a simplified cathode starvation protocol based on a gradual potential sequence applied using a single potentiostat (CSSP) is introduced for the rapid activation of three types of proton exchange membranes (PEMs) with thicknesses of 25, 75, and 125 μm. Electrochemical surface area (ECSA), Tafel slope, and power output at 0.6 V confirmed effective activation of fuel cells with PEMs of 25 and 75 μm by CSSP, whereas additional activation was required to fully activate cells with 125-μm PEMs. Activation effectiveness was found to depend not only on PEM thickness but also on membrane phenomena. Supplying nitrogen to the cathode during the CSSP starvation stage mitigated mass-transport limitations for fuel cells incorporating 25-μm PEMs. The presented CSSP protocol required only 28 min─compared with 240 min for the conventional constant-potential (CP) method─while reducing hydrogen consumption by 76%. Moreover, it exhibited a higher power gain factor than recently reported hydrogen-pumping activation protocols within a comparable activation time. These findings can contribute to the future hydrogen society by enabling PEMFCs with high-speed and fuel-efficient activation.