Review: Durability and Degradation Issues of PEM Fuel Cell Components

TLDR

Durability, alongside cost reduction, is the most critical issue for commercializing PEM fuel cells, with voltage degradation as low as 1–2 µV·h under optimal conditions but increasing dramatically under load cycling, start–stop cycles, low humidification, high temperatures, or fuel starvation. The review seeks to assess degradation mechanisms of key PEM fuel cell components. The review examines degradation mechanisms of membranes, electrodes, bipolar plates, and seals. Long‑term experiments reveal the relative importance of these degradation mechanisms and the operating conditions that influence them.

Abstract

Abstract Besides cost reduction, durability is the most important issue to be solved before commercialisation of PEM Fuel Cells can be successful. For a fuel cell operating under constant load conditions, at a relative humidity close to 100% and at a temperature of maximum 75 °C, using optimal stack and flow design, the voltage degradation can be as low as 1–2 μV·h. However, the degradation rates can increase by orders of magnitude when conditions include some of the following, i.e. load cycling, start–stop cycles, low humidification or humidification cycling, temperatures of 90 °C or higher and fuel starvation. This review paper aims at assessing the degradation mechanisms of membranes, electrodes, bipolar plates and seals. By collecting long‐term experiments as well, the relative importance of these degradation mechanisms and the operating conditions become apparent.