In-situ quantification of solid oxide fuel cell electrode microstructure by electrochemical impedance spectroscopy

• 3D Ni-YSZ anode microstructure is reconstructed by XCT.
• Tortuosity factor of pores of the anode is estimated by DRT of impedance.
• Results of tortuosity factor by DRT analysis agree well with that by XCT analysis.
• DRT is a feasible technique for in-situ quantification of SOFC microstructures.

Three-dimensional (3D) microstructure of solid oxide fuel cell electrodes plays critical roles in determining fuel cell performance. The state-of-the-art quantification technique such as X-ray computed tomography enables direct calculation of geometric factors by 3D microstructure reconstruction. Taking advantages of in-situ, fast-responding and low cost, electrochemical impedance spectroscopy represented by distribution of relaxation time (DRT) is a novel technique to estimate geometric properties of fuel cell electrodes. In this study, we employed the anode supported cells with the cell configuration of Ni-YSZ || YSZ || LSM-YSZ as an example and compared the tortuosity factor of pores of the anode substrate layer by X-ray computed tomography and DRT analysis. Good agreement was found, validating the feasibility of in-situ microstructural quantification by using the DRT technique.

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