PHM-oriented degradation indicators for PEM fuel cells:What can be learnt from battery State of Charge estimation

As fuel cell technologies continue advancing, people are pursuing ways to extend their lifespan, especially for Proton Exchange Membrane (PEM) fuel cells. Within a prognostics and health management (PHM) approach, several techniques can provide an estimation of its state of health (SOH) and a prediction for the fuel cell’s remaining useful life (RUL) in order to help the manufacturers improving fuel cell performance. Before developing a solution for estimation and prediction, PHM issues for PEM fuel cells need to be firstly properly defined, in particular in terms of deterioration/ageing indicators used for the state estimation and prediction. This paper provides a benchmarking study of degradation/ageing indicators regarding PHM problems of PEM fuel cell by comparing with the ones of batteries since numbers of approaches are presented and developed to monitor battery health and charge status. The aim of this work is to investigate how the definition of suitable degradation indicators and the development of PHM solutions for the PEM fuel cell can benefit from the knowledge and the experience feedback in the field of battery PHM, with the final goal to develop a prognostic method for PEM fuel cells. To achieve this goal, the State of Charge (SOC), a key degradation indicator to battery prognostic assessment, is firstly studied.