Evaluation of stress condition of operated anode supported-type SOFC under operating conditions based on Raman scattering spectroscopy

Stress, temperature and dopant concentration dependences of Raman spectra were measured in rare-earth-doped ceria. By the results, the accuracy of stress conditions evaluation method in operating solid oxide fuel cells (SOFCs) with micro Raman scattering spectroscopy was improved. The shift of ceria F _2g vibration mode Raman peak was evaluated in this measurement. In addition to peak shift, we also focused on the dependences of peak width, i.e. full width half maximum (FWHM). Considering measurement accuracy and predicted stress conditions in operated SOFCs, FWHM was more sensitive to temperature and dopant concentration than peak position. Consequently, the method was improved to evaluate not only stress conditions but also dopant concentration and temperature with high spatial resolution. We demonstrated this method using the model cells of conventional anode-supported type SOFCs, and the results indicated that stress and dopant concentration were distributed in the cell over measurement error. Especially, standard deviation of stress value sometimes reached 30 % of stress values.