Long term Durability of High Temperature-Polymer Electrolyte Membrane Fuel Cells based on Acid Doped Polybenzimidazole

摘要

A PEM fuel cell with an operating temperature above 100°C is desired for increasing the kinetics of reactions, reduced sensitivity to impurities of the fuel, as well as for the reduction of the requirements on thermal and water management systems. High Temperature Polymer Electrolyte Membrane Fuel Cells (HT-PEMFC) can effectively be combined with CHP systems to offer a simple system design and higher overall system efficiencies. One of the challenges with phosphoric acid doped polybenzimidazole (PBI) membranes is the loss of or changes in phosphoric acid, which controls the proton conductivity, and the long-term endurance of the membrane electrode assembly. . In this work, Long term durability of a high-temperature proton exchange membrane fuel cell utilizing a phosphoric-acid-doped polybenzimidazole electrolyte is investigated. Fuel cell performance is measured by polarization curves to understand to understand the influence of varied parameters. Electrochemical impedance spectroscopy is employed to characterize the variations in the resistance and polarization losses in the cell. Moreover, Water at the fuel cell exhaust is collected to measure P concentration by inductively coupled plasma-Optical emission spectroscopy.