A Study of Performance Heterogeneity in Solid Oxide Fuel Cell Stacks Induced by Flow Field Disparity

To address the research gap in inter‐cell performance uniformity during solid oxide fuel cell (SOFC) stack scale‐up, a reduced‐order three‐dimensional multiphysics model was developed for assemblies containing 5–20 representative cell units. The model is designed to isolate the effect of external‐manifold‐induced inter‐cell flow maldistribution while retaining coupled fluid flow, species transport, heat transfer, and electrochemical reactions within each representative channel‐rib unit. Results show that increasing the number of cell units from 5 to 20 raises the inter‐cell inlet‐velocity deviation from 0.00572 to 0.0683 m·s ⁻¹ (1094%). The associated fuel‐utilization deviation increases from 2.9% to 53.9%, and the cell‐voltage deviation increases from 3.06 to 35.64 mV. Moreover, voltage uniformity becomes markedly more sensitive to increasing fuel utilization when the initial inter‐cell flow disparity is large. The results identify a transmission pathway of “inter‐cell flow disparity–fuel residence time and reactant availability–local electrochemical response–cell output heterogeneity.” Because each planar cell is represented by one periodic channel‐rib unit, the model does not resolve channel‐to‐channel redistribution inside an actual multichannel cell; the reported trends therefore quantify manifold‐driven inter‐cell effects under a controlled internal flow‐field configuration.