Comparative analysis for thermal management strategies in the design of PEMFC bipolar plates using different flow patterns

The rapid depletion of fossil fuel reserves and their environmental consequences have catalyzed the search for alternative energy sources. Proton exchange membrane fuel cells (PEMFCs) are one of the most promising technologies, with efficiencies of over 60 % in energy conversion and zero-emission operation. However, commercialization is limited by issues with water and thermal management, particularly in the flow field design, which has direct implications for performance, durability, and efficiency. Prior research has determined that optimized flow field geometries can improve PEMFC performance through improved reactant distribution and water removal. However, most of the research has only been concerned with the anode side or with simplified models, with little quantitative validation based on experimentation. This work overcomes these limitations by carrying out an extensive three-dimensional computational fluid dynamics (CFD) simulation of six different cathode-side flow field geometries labeled A to F on a PEMFC with an active area of 25 cm². It was verified experimentally with a polarization curve measurement and temperature test, having less than 4 % error in pressure drop and < 6 % accuracy in temperature prediction. The greatest peak power density of 0.85 W cm⁻² of optimized Design E, or 47.08 % of reference Design A 0.58 W cm⁻², pertained to considered designs. Design E also showed a reduction in water saturation of 30 % and an oxygen concentration of 0.212 mol/m³ at the exit of the cathode, 18.5 % higher than that for Design A. It also exhibited the lowest pressure drop, ∼ 800 Pa, and the highest maximum uniformity of temperature and current density distribution uniformity index of 0.79. Other optimized geometries, B, C, D, and F, achieved mean power density improvements of 12.60 % and 20.00 % with various trade-offs in pressure drop and water management. Experimental results quantitatively demonstrate that the intentional optimization of cathode flow field geometry can significantly enhance PEMFC efficiency, water management, and thermal homogeneity. The validated CFD method is a reliable tool for future design and scale-up optimization of PEMFC systems, especially in automotive, aerospace, and portable power applications. This research adds a comprehensive performance matrix that can be used to inform the design of next-generation, high-efficiency, corrosion-resistant PEMFC flow fields.