Fine three-dimensional simulation of the heterogeneous anode of a solid oxide fuel cell with direct internal reforming

The performance of direct internal reforming solid oxide fuel cells (DIR-SOFCs) depends on the coupling of multiphysics field and electrode microstructure. This study develops a heterogeneous model for a DIR-SOFC anode based on a microstructure reconstructed using X-ray. The control equations are accurately defined at the corresponding geometry characteristic in accordance with the actual physical phenomena. The distributions of activation overpotential and molar fractions of substances are investigated. The effects of total overpotential, prereforming extent, and operating temperature are discussed. Electrochemistry reaction rate is faster than reforming reaction rate and is fluctuating at a microscale. Total overpotential has an insignificant effect on CH₄ conversion rate, but operating temperature has a significant effect on CH₄ conversion rate and electrical performance of cell. Higher prereforming extent of methane is beneficial for elevating electrical performance. The present model is beneficial for the study on the relationship between the microstructure and cell performance.