A hybrid degradation index for characterizing the degradation state of proton exchange membrane fuel cells

Prognostics and health management (PHM) is considered a critical method to extend the lifetime of the proton exchange membrane fuel cell (PEMFC) and reduce maintenance costs. The premise of PHM is to establish a reliable and general degradation index. Electrodes and membranes are components that mostly influence the degradation processes of PEMFC. Combining the two catalyst and membrane degradation indexes, this paper establishes a hybrid degradation index for estimating the PEMFC degradation state in different operating conditions. Firstly, membrane and catalyst degradation models are utilized to estimate a single degradation index. Then, the two normalized single degradation indexes are fused to construct a hybrid degradation index. The validity of the indexes is analyzed through experimental data. The hybrid degradation index is suitable for predicting the degradation state and estimating the remaining useful life (RUL) of PEMFC.