Analysis of the cathode side of a PEMFC varying design parameters to optimize current distribution and power density

The amount and distribution over the active area of current density produced by the stack is a key aspect of a fuel cell performance. The performance of a proton exchange membrane fuel cell (PEMFC) is affected by many factors, including the operating conditions, flow field and manifold design, and membrane performance. In the present study, a 3D multiphysics model of a PEMFC half-cell focused in the cathode side is developed. Statistical analysis tools are proposed to quantitatively evaluate the current density distribution on the active area of the electrode in order to guarantee a proper distribution while maintaining power density. The analysis was done choosing four design parameters at three different levels on which a fractional factorial experimental design provided by the Taguchi method was applied. Finally the 0.65 V working potential, that guarantees a good power generation and its adequate density current distribution on the active area of the cell, is selected. The best conditions were obtained with geometries of parallel channels, maximum gas diffusion layer porosity, maximum inlet air velocity and minimum vapor fraction, this combination improves 2.31 times the power generated in the worst case analyzed.