Dasari, Hari Prasad Park, Sun-Young Kim, Jeonghee Lee, Jong-Ho Kim, Byung-Kook Je, Hae-June Lee, Hae-Weon Yoon, Kyung Joong 2024-01-20T11:30:19Z 2024-01-20T11:30:19Z 2021-09-04 2013-10-15 0378-7753 https://pubs.kist.re.kr/handle/201004/127546 Electrochemical performance of Ni-yttria stabilized zirconia (YSZ) electrode, which is widely used as the anode for solid oxide fuel cells (SOFCs), is evaluated for H-2 production in solid oxide electrolysis cells (SOECs). The impedance spectra of Ni-YSZ electrode are composed of two major depressed arcs. The high-frequency impedance (>10(4) Hz) can be assigned to transfer of the charged species across the Ni/YSZ interface, and the mid-frequency arc (10(2)similar to 10(3) Hz) is possibly associated with the gas-solid interaction such as adsorption, dissociation, desorption, etc. The impedance spectra are strongly influenced by the gas composition in both fuel cell (H-2 oxidation) and electrolysis (H2O reduction) reactions; polarization resistance decreases with increasing concentration of the reactant species. In fuel cell mode, both high- and mid-frequency arcs increase with decreasing H-2 concentration, while the impedance spectra are dominated by the mid-frequency arc and the high-frequency arc remains negligible even at low H2O concentration in electrolysis mode. Reaction mechanisms and elementary reaction pathways for H-2 oxidation and H2O reduction are suggested based on impedance spectra. The minimum impedance is observed at 50% H2O in electrolysis mode, and further increase in H2O concentration causes degradation of the electrode performance, possibly due to local oxidation of Ni. (C) 2013 Elsevier B.V. All rights reserved. English ELSEVIER HIGH-TEMPERATURE ELECTROLYSIS GLASS-CERAMIC SEALANTS IMPEDANCE SPECTROSCOPY PLATINUM-ELECTRODES ISOTOPIC EXCHANGE CERMET ELECTRODES SURFACE-DIFFUSION H-2 OXIDATION FUEL-CELLS NICKEL Electrochemical characterization of Ni-yttria stabilized zirconia electrode for hydrogen production in solid oxide electrolysis cells Article 10.1016/j.jpowsour.2013.05.033 1 JOURNAL OF POWER SOURCES, v.240, pp.721 - 728 JOURNAL OF POWER SOURCES 240 721 728 scie scopus 000321803700088 2-s2.0-84878896282 Chemistry, Physical Electrochemistry Energy & Fuels Materials Science, Multidisciplinary Chemistry Electrochemistry Energy & Fuels Materials Science Article HIGH-TEMPERATURE ELECTROLYSIS GLASS-CERAMIC SEALANTS IMPEDANCE SPECTROSCOPY PLATINUM-ELECTRODES ISOTOPIC EXCHANGE CERMET ELECTRODES SURFACE-DIFFUSION H-2 OXIDATION FUEL-CELLS NICKEL Solid oxide electrolysis cell Solid oxide fuel cell Impedance spectroscopy Rate limiting process