Modeling and characterization of sintered YSZ/NiO porous electrode structural properties using coarse-graining molecular dynamics method

Abstract

In solid oxide fuel cell (SOFC), sintering of YSZ and NiO powders into porous anode plays a crucial role in determining its overall performance. In this study, a coarse-graining (CG) molecular dynamics (MD) model is developed to capture sintered half-cell composed of porous functional layer with NiO/YSZ particles and dense YSZ ceramic electrolyte layer with applied in anode-supported SOFC. The sintering process is simulated in two stages, i.e., heating process followed by temperature-holding process. This study also explores effects of sintering parameters (e.g., temperature, powder size and material compositions) on structural characteristics, including distribution of sintered triple-phase boundary (TPB) length, porosity, and pore size. It is found that structural properties vary mainly during the heating stage of sintering, while a higher sintering temperature leads to a larger TPB length and a lower porosity, while increasing in diameter ratio of the NiO powders to YSZ powders is advantageous for increasing TPB length, porosity and size pores for promoting electrode electrochemical activity. This work provides a bottom-up approach for potential optimization of SOFC fabrication condition and parameters.