Reversible and Irreversible Degradation in PEM Fuel Cells

Abstract

In the fuel cell community there is no common way to describe voltage decay rates in MEA durability test. On this poster a comparison and assessment of various mathematical approaches to determine a voltage decay rate is presented. It turned out that for MEA life time prediction it is most adequate is to use voltage values before/after regular voltage recovery steps to calculated a conclusive decay rate. In the context of reversible and irreversible voltage losses a mechanistic approach (fitting of V-I curves) allows to study voltage decay processes and recovery mechanisms related to, e.g. cell shutdown (soak time) or potential sweeping (CV). Even though CV and shutdown lead to different effect, the power recovery due to a simple shutdown which is technologically applicable seems to be more effective than potential sweeping up to 1.2 V.