Effects of water coexisting on the cathode activity for the solid oxide fuel cells using LaGa 3-based perovskite oxide electrolyte

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The effects of water addition to an oxidant on the cathodic overpotential of La-doped BaCoO 3 and Sm 0.5Sr 0.5CoO 3 cathodes were investigated in this study. It was found that the overpotential of La-doped BaCoO 3 decreased by the addition of H 2O to oxygen. In particular, the decrease in the overpotential by addition of H 2O was greater with the decreasing operating temperature of the cell. Therefore, it becomes clear that the maximum power density increased by the addition of H 2O to the oxidant. Positive effects of water on the cathodic overpotential are also observed on Sm 0.5Sr 0.5CoO 3. Therefore, the positive effects of water on cathodic reaction are not limited to La-doped BaCoO 3, but are also expected on general oxide cathodes. The positive effects of a humidified oxidant were sustained stably over 50 h, and X-ray diffraction measurement suggests that there is no change in the crystal structure of an La-doped BaCoO 3 cathode or an LaGaO 3-based oxide electrolyte. The improved cathodic activity by addition of H 2O was studied further by using 18O surface exchange measurement. Although the diffusion coefficient was independent of the coexisting water, the surface exchange coefficient was greatly increased by the addition of water. Therefore, water existing in a cathode seems to assist the dissociation of oxygen into an oxide ion. Therefore, it is considered that a humidified oxidant is one of the effective methods to suppress the cathodic overpotential at decreased temperature.

Original languageEnglish
JournalJournal of the Electrochemical Society
Volume152
Issue number10
DOIs
Publication statusPublished - Nov 11 2005

Fingerprint

solid oxide fuel cells
Solid oxide fuel cells (SOFC)
Perovskite
Oxides
Electrolytes
Cathodes
cathodes
electrolytes
Oxidants
oxides
Water
water
Oxygen
oxygen
operating temperature
perovskite
radiant flux density
diffusion coefficient
Crystal structure
dissociation

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

Cite this

@article{730c25584bad4ade9cef129b70517d13,
title = "Effects of water coexisting on the cathode activity for the solid oxide fuel cells using LaGa 3-based perovskite oxide electrolyte",
abstract = "The effects of water addition to an oxidant on the cathodic overpotential of La-doped BaCoO 3 and Sm 0.5Sr 0.5CoO 3 cathodes were investigated in this study. It was found that the overpotential of La-doped BaCoO 3 decreased by the addition of H 2O to oxygen. In particular, the decrease in the overpotential by addition of H 2O was greater with the decreasing operating temperature of the cell. Therefore, it becomes clear that the maximum power density increased by the addition of H 2O to the oxidant. Positive effects of water on the cathodic overpotential are also observed on Sm 0.5Sr 0.5CoO 3. Therefore, the positive effects of water on cathodic reaction are not limited to La-doped BaCoO 3, but are also expected on general oxide cathodes. The positive effects of a humidified oxidant were sustained stably over 50 h, and X-ray diffraction measurement suggests that there is no change in the crystal structure of an La-doped BaCoO 3 cathode or an LaGaO 3-based oxide electrolyte. The improved cathodic activity by addition of H 2O was studied further by using 18O surface exchange measurement. Although the diffusion coefficient was independent of the coexisting water, the surface exchange coefficient was greatly increased by the addition of water. Therefore, water existing in a cathode seems to assist the dissociation of oxygen into an oxide ion. Therefore, it is considered that a humidified oxidant is one of the effective methods to suppress the cathodic overpotential at decreased temperature.",
author = "Tatsumi Ishihara and Satoko Fukui and Hiroshige Matsumoto",
year = "2005",
month = "11",
day = "11",
doi = "10.1149/1.2032407",
language = "English",
volume = "152",
journal = "Journal of the Electrochemical Society",
issn = "0013-4651",
publisher = "Electrochemical Society, Inc.",
number = "10",

}

TY - JOUR

T1 - Effects of water coexisting on the cathode activity for the solid oxide fuel cells using LaGa 3-based perovskite oxide electrolyte

AU - Ishihara, Tatsumi

AU - Fukui, Satoko

AU - Matsumoto, Hiroshige

PY - 2005/11/11

Y1 - 2005/11/11

N2 - The effects of water addition to an oxidant on the cathodic overpotential of La-doped BaCoO 3 and Sm 0.5Sr 0.5CoO 3 cathodes were investigated in this study. It was found that the overpotential of La-doped BaCoO 3 decreased by the addition of H 2O to oxygen. In particular, the decrease in the overpotential by addition of H 2O was greater with the decreasing operating temperature of the cell. Therefore, it becomes clear that the maximum power density increased by the addition of H 2O to the oxidant. Positive effects of water on the cathodic overpotential are also observed on Sm 0.5Sr 0.5CoO 3. Therefore, the positive effects of water on cathodic reaction are not limited to La-doped BaCoO 3, but are also expected on general oxide cathodes. The positive effects of a humidified oxidant were sustained stably over 50 h, and X-ray diffraction measurement suggests that there is no change in the crystal structure of an La-doped BaCoO 3 cathode or an LaGaO 3-based oxide electrolyte. The improved cathodic activity by addition of H 2O was studied further by using 18O surface exchange measurement. Although the diffusion coefficient was independent of the coexisting water, the surface exchange coefficient was greatly increased by the addition of water. Therefore, water existing in a cathode seems to assist the dissociation of oxygen into an oxide ion. Therefore, it is considered that a humidified oxidant is one of the effective methods to suppress the cathodic overpotential at decreased temperature.

AB - The effects of water addition to an oxidant on the cathodic overpotential of La-doped BaCoO 3 and Sm 0.5Sr 0.5CoO 3 cathodes were investigated in this study. It was found that the overpotential of La-doped BaCoO 3 decreased by the addition of H 2O to oxygen. In particular, the decrease in the overpotential by addition of H 2O was greater with the decreasing operating temperature of the cell. Therefore, it becomes clear that the maximum power density increased by the addition of H 2O to the oxidant. Positive effects of water on the cathodic overpotential are also observed on Sm 0.5Sr 0.5CoO 3. Therefore, the positive effects of water on cathodic reaction are not limited to La-doped BaCoO 3, but are also expected on general oxide cathodes. The positive effects of a humidified oxidant were sustained stably over 50 h, and X-ray diffraction measurement suggests that there is no change in the crystal structure of an La-doped BaCoO 3 cathode or an LaGaO 3-based oxide electrolyte. The improved cathodic activity by addition of H 2O was studied further by using 18O surface exchange measurement. Although the diffusion coefficient was independent of the coexisting water, the surface exchange coefficient was greatly increased by the addition of water. Therefore, water existing in a cathode seems to assist the dissociation of oxygen into an oxide ion. Therefore, it is considered that a humidified oxidant is one of the effective methods to suppress the cathodic overpotential at decreased temperature.

UR - http://www.scopus.com/inward/record.url?scp=27644528468&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27644528468&partnerID=8YFLogxK

U2 - 10.1149/1.2032407

DO - 10.1149/1.2032407

M3 - Article

AN - SCOPUS:27644528468

VL - 152

JO - Journal of the Electrochemical Society

JF - Journal of the Electrochemical Society

SN - 0013-4651

IS - 10

ER -