PEM fuel cell testing by electrochemical impedance spectroscopy

Nowadays, proton exchange membrane fuel cells (PEMFC) are candidate as middle term power sources for automotive, stationary generation and portable power applications. In order to introduce these devices into the market an improvement in their performances seems necessary, as well as the development of an effective control system able to find their optimal operating conditions. This paper deals with electrochemical impedance spectroscopy (EIS) using an effective tool, where a cost-effective measurement hardware has been developed creating a software to analyze the results. Both single fuel cells and stacks have been tested in various operating conditions. This experimental approach allows to highlight variations of model parameters and to perform a further analysis of the processes occurring in a fuel cell through electrical circuit models. A special attention is given to the experimental results, in order to address fuel cell malfunctions using the EIS approach as an effective diagnostic method. (author)