Electrochemical ageing study of mixed lanthanum/praseodymium nickelates La2-PrNiO4+δ as oxygen electrodes for solid oxide fuel or electrolysis cells
Résumé
The chemical and electrochemical stability of lanthanide nickelates La2NiO4+δ (LNO), Pr2NiO4+δ (PNO) and their mixed compounds La2-xPrxNiO4+δ (LPNOs) with x = 0.5, 1 or 1.5 is reported. The aim is to promote these materials as efficient electrodes for solid oxide fuel cell (SOFC) and/or solid oxide electrolysis cell (SOEC). La2NiO4+δ and La1.5Pr0.5NiO4+δ compounds are chemically very stable as powders over one month in the temperature range 600 − 800°C, while the other materials rich in praseodymium progressively decompose into various perovskite-deriving components with additional Pr6O11. Despite their uneven properties, all these materials are quite efficient and sustainable as electrodes on top of gadolinium doped ceria (GDCBL) // yttrium doped zirconia (8YSZ) electrolyte, for one month at 700°C without polarization. Under polarization (300 mA·cm−2), the electrochemical performances of LNO, PNO and La1.5Pr0.5NiO4+δ (LP5NO) quickly degrade in SOFC mode, i.e. for the oxygen reduction reaction, while they show durability in SOEC mode, i.e. for the oxide oxidation reaction.
Domaines
Matériaux
Origine : Fichiers produits par l'(les) auteur(s)
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