X-ray stress measurement of solid oxide fuel cell using synchrotron radiation

Residual thermal stresses in the electrolyte of the anode-supported planar SOFC were measured using the X-ray diffraction method. The cell tested was fabricated by co-sintering screen printed 8YSZ electrolyte on NiO/YSZ substrate at 1500°C. The thickness of the electrolyte and the anode were about 30μm and 2 mm, respectively. To estimate the residual stress precisely, the synchrotron radiation was used as an excellent X-ray source. The wavelength of the radiation beam used for the stress measurements was λ = 0.154 nm, and (531) and (620) planes were selected for the diffracting planes. The estimated residual stress in the electrolyte of the anode-supported cell was a compressive stress of about 600 ∼ 720MPa at room temperature. In addition to the stress measurements, the residual stress distribution in the cell was simulated using the finite element method. The calculated principal stress in the electrolyte at room temperature was close to that estimated by the stress measurement.