Neodymium- and cobalt-based layered perovskite oxides with increasing Ba deficiency (NdBa1-xCo2O5+δ, x = 0.0 ÷ 0.2) are prepared via solid state firing. The chemical and electrochemical properties of these materials are characterized via XRD, SEM, TG-DTA, 4-probe conductivity measurement and EIS tests on symmetric cells. The maximum tolerated Ba deficiency is slightly below 10%. The compounds crystallize in an ordered layered structure with orthorhombic Pmmm (for x = 0 and 0.5) and tetragonal P4/mmm (for x = 0.10) crystal lattice. All the compounds show high total conductivity (between 400 and 600 S/cm at 700 °C). A remarkable tenfold decrease of the area specific resistance is observed at decreasing the Ba content from 0 to 10%, with the compound at 10% Ba deficiency reaching the best performance (0.1 Ω∗cm2 at 700 °C). Detailed equivalent circuit analysis on EIS tests at varying temperature (550 to 700 °C) and O2 content (100% to 5% v/v) reveals that the limiting steps are the transport of oxygen ions within the cathodic phase and across the electrolyte interface at high frequency, and the formation of an oxygen ion at intermediate frequency. The effect of Ba on the electrochemical mechanism is associated with a promotion of the bulk diffusion steps at high frequency.

(2015). Evaluation of Ba deficient NdBaCo2O5+δ oxide as cathode material for IT-SOFC [journal article - articolo]. In ELECTROCHIMICA ACTA. Retrieved from http://hdl.handle.net/10446/51038

Evaluation of Ba deficient NdBaCo2O5+δ oxide as cathode material for IT-SOFC

Pelosato, Renato;Natali Sora, Isabella
2015-01-01

Abstract

Neodymium- and cobalt-based layered perovskite oxides with increasing Ba deficiency (NdBa1-xCo2O5+δ, x = 0.0 ÷ 0.2) are prepared via solid state firing. The chemical and electrochemical properties of these materials are characterized via XRD, SEM, TG-DTA, 4-probe conductivity measurement and EIS tests on symmetric cells. The maximum tolerated Ba deficiency is slightly below 10%. The compounds crystallize in an ordered layered structure with orthorhombic Pmmm (for x = 0 and 0.5) and tetragonal P4/mmm (for x = 0.10) crystal lattice. All the compounds show high total conductivity (between 400 and 600 S/cm at 700 °C). A remarkable tenfold decrease of the area specific resistance is observed at decreasing the Ba content from 0 to 10%, with the compound at 10% Ba deficiency reaching the best performance (0.1 Ω∗cm2 at 700 °C). Detailed equivalent circuit analysis on EIS tests at varying temperature (550 to 700 °C) and O2 content (100% to 5% v/v) reveals that the limiting steps are the transport of oxygen ions within the cathodic phase and across the electrolyte interface at high frequency, and the formation of an oxygen ion at intermediate frequency. The effect of Ba on the electrochemical mechanism is associated with a promotion of the bulk diffusion steps at high frequency.
articolo
2015
Donazzi, Alessandro; Pelosato, Renato; Cordaro, Giulio; Stucchi, Davide; Cristiani, Cinzia; Dotelli, Giovanni; NATALI SORA, Isabella
(2015). Evaluation of Ba deficient NdBaCo2O5+δ oxide as cathode material for IT-SOFC [journal article - articolo]. In ELECTROCHIMICA ACTA. Retrieved from http://hdl.handle.net/10446/51038
File allegato/i alla scheda:
File Dimensione del file Formato  
Natali Sora - Evaluation of BA deficient.pdf

Solo gestori di archivio

Versione: publisher's version - versione editoriale
Licenza: Licenza default Aisberg
Dimensione del file 6.58 MB
Formato Adobe PDF
6.58 MB Adobe PDF   Visualizza/Apri
10446_51038_PRE-PRINT Electrochimica acta.pdf

Open Access dal 30/09/2017

Versione: postprint - versione referata/accettata senza referaggio
Licenza: Creative commons
Dimensione del file 2.83 MB
Formato Adobe PDF
2.83 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Aisberg ©2008 Servizi bibliotecari, Università degli studi di Bergamo | Terms of use/Condizioni di utilizzo

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10446/51038
Citazioni
  • Scopus 51
  • ???jsp.display-item.citation.isi??? 49
social impact