Effect of MEA activation method on the long-term performance of PEM fuel cell

Abstract

In this paper, the influence of activation procedure on the long-term performance of membrane electrode assembly (MEA) is investigated. The MEAs are activated by most commonly used procedures; constant voltage and constant current. After activation, MEAs are implemented under 9000 aging cycles. During aging process, MEAs performance is evaluated using polarization curves, electrochemical impedance spectroscopy and cyclic voltammetry. The obtained results show that the activated MEA by constant current method shows an average voltage decay of 11.33 µV/cycle at 1 A/cm2, compared to 4.4 µV/cycle for the activated MEA by constant voltage procedure. This is due to the more reduction of electrochemical surface area for the activated MEA by constant current method (32% vs. 19%). Also, after 9000 degradation cycles, more severe platinum nanoparticles agglomeration is seen in the cathode catalyst layer of activated MEA by constant current procedure. This shows that MEA activation by constant current activation method not only need to the longer activation time, but also causes higher catalyst layer degradation.