Numerical simulation of the residual stress and failure probability of solid oxide fuel cells with nonplanar cathode–electrolyte interfaces

Abstract

ABSTRACT The actual surface of solid oxide fuel cells exhibits a fluctuating nature. In this study, the residual stresses and failure probability of nonplanar interfaces with different waveforms and wavelengths were investigated using a cosine interface approximation technique to simulate the actual cathode – electrolyte interface. Results showed that the electrolyte was subjected to compressive stresses with a maximum value at the trough. During cell preparation, the anode underwent conversion from an oxidized state to a reduced state, reducing residual stress in the electrode. Increasing the amplitude exerted a significantly greater effect on stress change than decreasing it. When the wavelength is longer, the stress fluctuation is lower. During anode reduction, the cathode reached the highest probability of failure and was damaged when the nickel oxide content exceeded 55%. A minimum anode thickness of 0.6 mm ensured anode stability.