Numerical multi-physical optimization of operating condition and current collecting setup for large-area solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are highly efficient energy conversion devices that generate electricity from hydrogen, offering a clean alternative to fossil fuels. A promising approach to enhance the power output of SOFC stacks is to increase the effective area of a single cell. However, experimental studies have revealed that simply scaling up the cell area—particularly in flat-tubular SOFCs with symmetric double-sided cathodes—can lead to reduced areal performance. Issues such as uneven gas distribution, extended current collection paths, and localized variations in current density contribute to this performance loss, highlighting the need for systematic optimization.

A study published in Frontiers in Energy by researchers from Harbin Institute of Technology, Shenzhen University, Ningbo Institute of Materials Technology and Engineering, and Nanyang Technological University addresses these challenges. They developed a multi-physical model to analyze and optimize the operation of large-area SOFCs. The research introduces a numerical approach coupling electrochemical, thermal, and fluid dynamics processes to evaluate and enhance cell performance under scaled-up conditions.

Using three-dimensional simulations validated against experimental data, the team compared SOFCs with effective areas of 3505.5 mm²(SOFC_S) and 26400 mm² (SOFC_L). Results showed that the larger cell suffered from lower reactant concentration and non-uniform current density, particularly in central regions. Through parametric studies, the researchers optimized inlet gas flow rates—identifying 3.5 m/s for hydrogen and 10 m/s for air as ideal—which improved gas distribution and elevated average current density. Furthermore, incorporating 45 Ni wires into the anode support enhanced current collection efficiency. Combined, these measures increased current density by 42% at 0.9 V compared to the baseline with default flow rates and no current collector enhancement.

This work demonstrates that through carefully tuned operational parameters and improved current collection, the performance of large-area SOFCs can be significantly enhanced without compromising mechanical stability. The study provides a validated modeling framework for guiding the design and operation of high-power SOFC stacks, supporting their commercial development. Future work will focus on geometric optimizations to further improve current and temperature uniformity.

Original source:

https://link.springer.com/article/10.1007/s11708-023-0919-z

https://journal.hep.com.cn/fie/EN/10.1007/s11708-023-0919-z

Shareable link：

https://rdcu.be/eRYYZ

Keywords:

solid oxide fuel cell (SOFC) / large effective area / flow rate / discharge performance / current collection