Yoon, SP Nam, SW Han, J Lim, TH Hong, SA Hyun, SH 2024-01-21T07:42:25Z 2024-01-21T07:42:25Z 2021-09-02 2004-01 0167-2738 https://pubs.kist.re.kr/handle/201004/137982 The relation between electrode microstructure and gas diffusion has been investigated with different morphologies of Pt electrodes by using AC impedance techniques. The measurements were carried out at temperatures of 873-1273 K and oxygen partial pressure (P-O2) of 0.01-1 atm. Gas-phase diffusion was observed only for high-performance electrodes at the high-temperature (1073-1273 K) and low-oxygen-partial-pressure regions (<0.1 atm P-O2). Considering the physical and electrochemical characteristics of impedance arcs, it was found that the arc at the frequency of below 1 Hz was related to gas conversion resistance, while the arc at the frequency of around 10 Hz represented pore diffusion resistance through the current-collecting part. For a thick electrode with a low porosity, however, gas diffusion resistance through pores of an electrode was observed at a frequency of around 100 Hz. From the results of a comparison of electrode performances with different electrode micro structures, electrochemical reaction sites (ERS) are supposed to be located at the peripheral line of Pt and YSZ as well as the Pt/YSZ interfaces where reaction gas can easily diffuse. (C) 2003 Elsevier B.V. All rights reserved. English ELSEVIER POLARIZATION INTERFACE CATHODES Effect of electrode microstructure on gas-phase diffusion in solid oxide fuel cells Article 10.1016/j.ssi.2003.10.010 1 SOLID STATE IONICS, v.166, no.1-2, pp.1 - 11 SOLID STATE IONICS 166 1-2 1 11 scie scopus 000220610200001 2-s2.0-1442287062 Chemistry, Physical Physics, Condensed Matter Chemistry Physics Article POLARIZATION INTERFACE CATHODES solid oxide fuel cell electrode microstructure gas-phase diffusion impedance analysis electrochemical reaction site