Enhancing uniformity and performance in Solid Oxide Fuel Cells with double symmetry interconnect design

Abstract

This study presents a novel interconnect design for planar solid oxide fuel cells (SOFCs) to improve the uniformity of operating environments, particularly in temperature, species, and electrochemical reaction distributions. Traditional cross-flow design suffers from asymmetries that lead to non-uniform temperature distributions and uneven fuel distribution, which can degrade stack performance over time. A new design with enhanced symmetry is introduced to address these challenges by positioning gas manifold holes along two diagonal axes. Also, flow and species distribution uniformity are achieved by implementing a flow resistance strategy that adjusts channel widths across the interconnect. Computational simulations using a highly reliable, experimentally validated numerical model confirm that the new design reduces the difference between maximum and minimum values in temperature by 34 %, hydrogen molar fraction in fuel by 13.3 %, and current density (i.e., electrochemical reaction) by 8.7 % compared to the traditional cross-flow design. The design improvements are achieved solely through geometric modifications, without altering material properties or introducing new components, maintaining manufacturability. This design offers the potential for expanding the operational window and improving the overall efficiency of SOFC stacks, contributing to more stable and high-performance energy systems.