Novel macro-Segmented Fuel Cell approach to investigation of localized degradation in PEMFCs

Here we present a novel concept of a segmented fuel cell, developed to fully and independently characterize four macro- segments of a single cell without introducing any modification to the MEA structure itself. This permits complete characterization of local electrochemical performance (using polarization curves, impedance spectra, cyclic and linear voltammetry) and mass composition (via gas-chromatography) during durability tests. Moreover, each of the four segments is fitted with an innovative reference electrode using an external, through-plane array configuration, enabling separation of anode and cathode contributions and their spatial evolution. This setup has been firstly applied to generate unprecedented insights into the evolution of local performance during DMFC operation. The variation of anode and cathode potential as a function of location within the cell and the correlation with heterogeneous current density distribution are discussed.