In order to evaluate the performance of a fuel cell and to investigate electrochemical reactions and degradation mechanisms, different testing methods are required. Apart from electrochemical testing (e.g. electrochemical impedance spectroscopy), cells are characterized post-mortem by various microscopy techniques.
An electrochemical single cell test might be performed in the following way: At the beginning, the single cell is electrochemically tested at different temperatures and gas compositions to gain information on the performance of individual cell components. To develop a profound understanding of its degradation behavior the cell is operated for 1000h and more under various/constant operating conditions.