Design, optimization and testing of baffle-type parallel-channel flow field plates within a 200-cm2 fuel cell short stack with a highly-active catalyst
Enhancing the current and power density in polymer electrolyte membrane fuel cells (PEMFCs) is one of the main challenges to their large-scale commercialization and hence in tune with the pending needs of the PEMFC industry. The volumetric power density in PEMFC stacks is strongly affected by the flow field plates due to their critical impact on the reactants distribution over the electrodes and their bulky size. In the proposed research, baffle-type parallel-channel cathode, anode and cooling flow field plates are designed with a small thickness. The flow distributions over these thin plates are optimized through computational fluid dynamics (CFD) simulations combined with experimental verifications and flow visualization. Since the flow field plates in stacks behave differently than in single cells, both original and optimized plates are tested within a fabricated 200-cm2 short stack. Comparative study of the polarization curves for the two original and optimized plates provides an in-depth understanding of the impact of the flow field design on the stack performance. An in-house high activity core-shell catalyst is tested with the optimized plates within the fabricated stack in the hope of achieving a current density as high as 1.5 A/cm2.