Increasing the stability of membrane-electrode assemblies based on Aquivion® membranes under automotive fuel cell conditions by using proper catalysts and ionomers

Abstract

The large-scale application of polymer electrolyte membrane fuel cells (PEMFCs) requires a reduction of the costs and an improvement in performance and stability. Particularly, the automotive market needs the PEMFC works under harsh conditions (high temperature, low relative humidity, etc.), maintaining a good performance level and low degradation. These operating conditions permit to mitigate the constraints concerning the thermal and water management allowing both a simplification and a volume reduction of the system inside the car with a strong impact on costs and reliability. However, PEMFCs require the development of the components such as catalysts, ionomers and membranes with a proper stability.

In this work, PtCo/KB and Pt/KB electrocatalysts were investigated with the aim of verifying the performance and stability, coupling them with an innovative reinforced Aquivion® membrane. An optimization of the catalytic ink composition was carried out, according to the different ionomers characteristics to be used in the catalytic layer in order to reduce the degradation level. The stability is assessed by considering the variations of the performance and electrochemical parameters, such as electrochemical surface area (ECSA) and mass activity (jm), at the beginning and end of accelerated stress test procedures.