An adaptive thermo-mechanical peridynamic model for crack analysis in anode-supported solid oxide fuel cell

Abstract

Nickel–yttria-stabilized zirconia (Ni–YSZ) composite cermet is widely used as the conventional anode material in solid oxide fuel cells (SOFCs) for both functional and supporting layers under high-temperature operating conditions. Although with high energy conversion efficiency and multi-fuel compatibility, the cell always suffers irreversible gradual degradation and sudden deterioration, which can be attributed to mechanical damages formed during thermal cycling and long-time operation. In this study, the three-dimensional (3D) real microstructures of various porous Ni–YSZ anodes are reconstructed using the focused ion beam-scanning electron microscopy (FIB-SEM) dual-beam technique. Based on the reconstructions, a weakly coupled thermo-mechanical peridynamic (PD) model is proposed to predict the possible mechanical damages under severe conditions for different anodes associated with the single-cell design under thermal shocks. The relevant equivalent mechanical and thermal properties of the composite anodes are analyzed and correlated to the real microstructures. The work provides a trans-scale model to simulate the generation and propagation of cracks based on the microstructural characteristics, and the simulation results show great potential in providing supporting information for trans-scale optimization of SOFCs.