Electrochemical Impedance Spectroscopy for the on-board diagnosis of PEMFC via on-line identification of Equivalent Circuit Model parameters

Abstract

Proton Exchange Membrane, also named Polymer Electrolyte Membrane fuel cells (PEMFC) are interesting devices for energy conversion. Their development is due to the high efficiency, acceptable power density, quick start-up and good environmental compatibility. On the other hand, reliability cost and durability are the main challenges for PEM fuel cell commercialization. In 2010 the American Department of Energy (DoE) sets a target of 40000 hours for stationary and 5000 hours for automotive applications, respectively. Actually, these standards are considered as the mainly reference in fuel cell research. Based on electro-catalytic reactions, the PEMFC operation is influenced by system functioning conditions. In case of system operation in abnormal conditions several chemical, mechanical and thermal degradation mechanisms could take place inside the cell. Among other, improper water, thermal and gas managements can introduce a cell voltage drop, thus reducing the system performance. A long-term exposure to these phenomena causes the PEMFC lifetime reduction. Thus, a good system management is one of the primary targets to ensure suitable PEMFC durability. For this purpose, research activities are oriented towards the development of newest advanced monitoring and diagnostic algorithms. The primary goal is monitoring the system operation ensuring a correct system control. Moreover, the diagnostic tool (i.e. both algorithm and sensors) allows the detection of system component malfunctioning; it can isolate one or more faults that may have occurred causing the abnormal behaviour of the system operation...[edited by author]