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Flow field design for the distribution of reactants and products on the electrode surface plays an important role in the overall performance of the fuel cell. It acts as a crucial factor when the laboratory scale fuel cell is scaled up for commercial applications. In the present work, a novel flow field design is proposed and its usefulness for the fuel cell applications are evaluated in a high-temperature polymer electrolyte fuel cell. The proposed geometry retains some of the features of serpentine flow field such as multiple bends, while modifications are made in its inplane flow path to achieve comparatively uniform reactant and product distribution. A threedimensional CFD model is developed to analyze the effectiveness of the proposed flow field. An HT-PEFC is fabricated and experimented with the proposed flow field for experimental validation. Furthermore, a low-cost current distribution mapping device is developed to validate the current density distribution on the electrode obtained from the CFD model. It exhibits a mismatch of 4% in the spatial distribution of current density between the modelling and experimental results. The proposed design is capable of achieving higher uniformity in current distribution across the active area (0.998 for modified serpentine and 0.96 serpentine) compared to serpentine flow field. This aids in boosting the current density of the cell by 27% at 0.57 V operations.

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Undoped and doped poly(2,5‐benzimidazole) (ABPBI) membrane was prepared by solvent casting method using methane sulfonic acid as a solvent and phosphoric acid (H3PO4) as a doping agent. The concentration of H3PO4 was varied from 0 to 60 vol% to enhance the proton conductivity of the ABPBI membrane at higher temperature. Wide angle X‐ray diffraction analysis showed a decrease in crystallinity in ABPBI membrane with increase in H3PO4 doping concentration. The molecular signature and the presence of H3PO4 was observed in 1000–1500 cm−1 in the Fourier transform infrared spectra, which was also supported by a corresponding weight loss at 180°C–200°C in the thermogravimetric analysis. Undoped ABPBI membrane registered the Young's modulus (E) and hardness (H) values of 2.46 and 0.92 GPa, respectively, and the corresponding E and H values for 1.65 doping level of 60 vol% H3PO4 doped ABPBI membrane were 0.14 and 0.067 GPa, respectively. The 60 vol% H3PO4 doped ABPBI membrane with doping level of 1.65 showed highest proton conductivity value of 2.2 × 10−2 S/cm. The impedance spectroscopic analysis and the equivalent circuit model were discussed to understand the nature of proton conduction in H3PO4 doped ABPBI membrane. POLYM. ENG. SCI., 56:1366–1374, 2016. © 2016 Society of Plastics Engineers