Comparative Study of On‐Line Membrane Electrode Assembly Activation Procedures in Proton Exchange Membrane Fuel Cell

Abstract

The major objectives of this study are to identify the best activation procedure between commonly used procedures that can significantly reduce the conditioning duration and to understand the change in interfacial properties during conditioning. In order to do that, three on‐line activation procedures were employed for activating of identical MEAs in PEMFC and studied by polarization curve and electrochemical impedance spectroscopy (EIS). These methods are constant current (0.25 A cm–2) for 19 h, constant voltage (0.6 V) for 9 h, and USFCC protocol.The best performance was achieved by USFCC protocol within 15 h, but by constant voltage procedure, 96% of mentioned protocol was obtained during 6 h. So constant voltage activation proceeded remarkably fast, and most of the activation process was achieved in the first few hours.Obtained results from Nyquist plots during/after MEA conditioning indicate mentioned process are irreversible and interfacial structures of MEAs are different even after finishing of MEA break‐in. It could be affected the MEA performance and even its durability. These results are consistence with the obtained performance of activated MEAs either in H2/air or H2/O2 PEMFC. We found the mentioned constant current procedure consume long time without reaching to expectable performance even after 19 h.

Effects of Membrane Additives on PEMFC Conditioning

“…With increasing conditioning time, the MF capacitive loop changes, while the HF capacitive loop remains nearly constant. The HF loop has been explained as either the electronic contact impedance between the electrical loop and the gas diffusion layer, or the ionic ohmic drop coupling with double layer inside the active layer . This HF contact impedance can be fitted by a contact resistance R HF in parallel with a contact capacitance C HF .…”

“…A fuel cell temporarily exhibits below normal performance after initial manufacturing. Activation, also called break in/conditioning/incubation/activating/commissioning, increases fuel cell performance until it reaches a plateau . Typically, conditioning is a time‐consuming and costly process of PEMFC manufacturing, especially for high volume production.…”

“…For this purpose, it is essential to have a better understanding on the activation mechanism of fuel cell conditioning with various membrane additives. There have been some studies with commercial products without additives on shortening conditioning time and maximizing fuel cell performance in the literature . The studies on the effects of membrane additives such as organic additives and inorganic/organic additives on fuel cell conditioning are however scarce.…”

Influence of the Cathode Catalyst Layer Void Volume on the Short‐term and Long‐term Performance of PEM Fuel Cell

“…The prepared MEAs were placed in a 5 cm 2 single cell (AHNS Co.) and then were connected to a fuel cell test system (Scribner, model 850e). Since the activation process plays an important role on PEMFC performance , the assembled MEAs were activated by a constant voltage procedure at 0.6 V . After this activation process, the experiments were carried out under pressure of 0.35 bar of hydrogen and oxygen; while the different cell temperature and cathode/anode relative humidity (RH) were applied at each step of experiments.…”

Optimization of catalyst layer composition for PEMFC using graphene-based oxygen reduction reaction catalysts

“…The removal of impurities on the catalyst surface and hydration of Nafion in the membrane and catalyst layer were suggested as the two main activation mechanisms [52]. The optimum Nafion content electrodes have no activation characteristics (Fig.…”