Analysis of Impedance Spectra for Segmented-in-Series Tubular Solid Oxide Fuel Cells

The individual electrode processes from anode and cathode have been clearly identified from practical impedance spectra with high-frequency inductive impedances for the Mitsubishi segmented-in-series tubular solid oxide fuel cell by combining the distribution of relaxation time analysis and the complex nonlinear least square fitting. Anodic gas diffusion process and charge transfer reaction near anodic triple phase boundary appear at similar to 0.3 and 1000 Hz, respectively. Cathodic oxygen reduction processes appear at similar to 10 Hz at 700 degrees C, whereas the impedance arc over 10 000 Hz is dominated by the cathodic oxygen ion transfer through the (La,Sr)MnO(3) (LSM)/Y(2)O(3)-stabilized ZrO(2) (YSZ) interface and YSZ of the composite. The results also exhibit an excellent agreement with those from the analysis of difference in impedance spectra. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3494214] All rights reserved.