Impedance-Based Performance Analysis of Micropatterned Polymer Electrolyte Membrane Fuel Cells

Abstract Micropatterns applied to proton exchange membranes can improve the performance of polymer electrolyte fuel cells; however, mechanism underlying this improvement is yet be clarified. In study, a patterned membrane electrode assembly (MEA) was compared with flat one using electrochemical impedance spectroscopy and distribution relaxation time analysis. The micropattern positively affects oxygen reduction reaction by increasing area. However, simultaneously, pattern negatively gas diffusion because it lengthens average transport path through catalyst layer. addition, MEA more vulnerable flooding, but performs better than in low-humidity conditions. Therefore, composition, geometry, operating conditions micropatterned should comprehensively optimized achieve optimal performance.