ElectroSphere: Electrical Electronics Engineering Bulletin
Bifurcating Excellence: Nature Inspired Branching Strategies for Ultra Compact, High Power PEM Fuel Cells
Abstract
Mohammad Yaghoub Abdollahzadeh Jamalabadi
Proton exchange membrane fuel cells (PEMFCs) are central to the global transition toward clean energy, yet their widespread adoption is still hindered by limitations at both the material and system levels. This perspective article synthesizes recent advances that exploit a common design principle—branching—across two distinct length scales: the molecular architecture of polymer electrolyte membranes and the geometric design of bipolar plate flow fields. In the membrane, introducing branched polymer backbones improves oxidative stability, reduces fuel crossover, and maintains high proton conductivity compared with linear analogues. In the flow field, nature-inspired branching networks, emulating lungs and leaf veins, deliver uniform reactant distribution, superior water management, and substantially enhanced volumetric power density. A critical examination of the literature shows that while both strategies individually yield significant performance gains, the optimal degree of branching is application-specific and demands careful balancing. The article also presents a detailed numerical model of a high-temperature PEMFC with a branching flow field, used to investigate the effect of branch channel width on mass transport and cell performance. Murray’s law, an analytical principle for optimal vascular networks, is introduced as a guiding criterion to determine the ideal hydraulic dimensions of branching channels. The model solves coupled charge, mass, and momentum conservation equations, and a parametric study identifies the influence of channel width ratio on current density and water distribution. Finally, the article outlines a vision for the intelligent co-design of branched membrane–electrode assemblies, paving the way for durable, high- power-density fuel cell stacks