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Enhanced Performances of Structured Oxygen Electrodes for High Temperature Steam Electrolysis
Author(s) -
Ogier T.,
Bassat J. M.,
Mauvy F.,
Fourcade S.,
Grenier J. C.,
Couturier K.,
Petitjean M.,
Mougin J.
Publication year - 2013
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201200201
Subject(s) - high temperature electrolysis , dielectric spectroscopy , non blocking i/o , electrolysis , electrode , overpotential , materials science , electrolyte , polarization (electrochemistry) , electrochemistry , oxide , reversible hydrogen electrode , anode , standard hydrogen electrode , hydrogen , analytical chemistry (journal) , oxygen , inorganic chemistry , chemical engineering , reference electrode , chemistry , catalysis , metallurgy , organic chemistry , engineering , biochemistry , chromatography
The present study is focused on alternative structured oxygen electrodes for solid oxide electrolysis cells (SOEC). The Ln 2 NiO 4+δ (Ln = La or Pr) nickelate oxides were selected as innovative electrode materials with respect to their mixed electronic and ionic conductivity. A thin interfacial ceria‐based layer was added in between the electrode and the zirconia‐based electrolyte to improve mechanical and electrochemical properties and to limit the chemical reactivity. These structured cells were characterized by electrochemical impedance spectroscopy on symmetrical cells, under zero dc conditions and anodic polarization. Low polarization resistance R P and improved anodic overpotential η A versus current density curves were obtained for the Pr 2 NiO 4+δ electrode with Ce 0.8 Y 0.2 O 2–δ interlayer: R P is decreased down to 0.06 Ω cm 2 at 800 °C, under air and zero dc conditions. Then, complete hydrogen electrode‐supported cells including Pr 2 NiO 4+δ as oxygen electrode were electrochemically characterized. At 800 °C, when the inlet gas composition is 90 vol.% H 2 O–10 vol.% H 2 at the hydrogen electrode, air being swept at the oxygen electrode, the current density determined at 1.28 V reaches –0.9 A cm –2 , the corresponding steam to hydrogen conversion ratio being 58%. These results are compared to those obtained with a reference cell including the oxygen deficient perovskite La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3–δ as oxygen electrode.