Three-dimensional Numerical Simulation of Solid Oxide Fuel Cell Anode Microstructure

Solid oxide fuel cell (SOFC) is a clean and efficient power generation device, whose electrode microstructure directly affects the electrochemical performance of the cell. In this paper, we obtained the SOFC anode microstructure by X-ray technique, defined the charge and matter conduction in the bulk phase material and the electrochemical reaction in the three-phase boundary line, established a three-dimensional microscopic model of the electrochemical-mass transfer coupling of the SOFC anode, and compared the polarization characteristics of the two microstructures at 800◦C. It is shown that the microstructure has a great influence on the physical field distribution inside the electrode, and the closer to the electrolyte interface of the electrode, the stronger the activation polarization and ionic potential fluctuations. A large mass transfer resistance exists near the throat of the fine electrode pore phase, forming a significant concentration polarization jump. Activation polarization and ohmic polarization are comparable in size, each occupying more than 45% of the total losses. The model in this paper can be used to study the cell degradation caused by microstructural changes and the optimal design of electrodes. © 2023 Science Press. All rights reserved.