Sr0.02La0.98Nb1–-xTaxO4 (SLNT, with x=0.1, 0.2, and 0.4) proton conducting oxides were synthesized by solid state reaction for application as electrolyte in solid oxide fuel cells operating below 600 °C. Dense pellets were obtained after sintering at 1600 °C for 5 h achieving a larger average grain size with increasing the tantalum content. Dilatometric measurements were used to obtain the SLNT expansion coefficient as a function of tantalum content (x), and it was found that the phase transition temperature increased with increasing the tantalum content, being T=561, 634, and 802 °C for x=0.1, 0.2, and 0.4, respectively. The electrical conductivity of SLNT was measured by electrochemical impedance spectroscopy as a function of temperature and tantalum concentration under wet (pH2O of about 0.03 atm) Ar atmosphere. At each temperature, the conductivity decreased with increasing the tantalum content, at 600 °C being 2.68×10−4, 3.14×10−5, and 5.41×10−6 Scm−1 for the x=0.1, 0.2, and 0.4 compositions, respectively. SLNT with x=0.2 shows a good compromise between proton conductivity and the requirement of avoiding detrimental phase transitions for application as a thin-film electrolyte below 600 °C.

Santibanez Mendieta, A., Fabbri, E., Licoccia, S., Traversa, E. (2012). Tailoring phase stability and electrical conductivity of Sr0.02La0.98Nb1–xTaxO4 for intermediate temperature fuel cell proton conducting electrolytes. SOLID STATE IONICS, 216, 6-10 [10.1016/j.ssi.2011.09.019].

Tailoring phase stability and electrical conductivity of Sr0.02La0.98Nb1–xTaxO4 for intermediate temperature fuel cell proton conducting electrolytes

LICOCCIA, SILVIA;TRAVERSA, ENRICO
2012-01-01

Abstract

Sr0.02La0.98Nb1–-xTaxO4 (SLNT, with x=0.1, 0.2, and 0.4) proton conducting oxides were synthesized by solid state reaction for application as electrolyte in solid oxide fuel cells operating below 600 °C. Dense pellets were obtained after sintering at 1600 °C for 5 h achieving a larger average grain size with increasing the tantalum content. Dilatometric measurements were used to obtain the SLNT expansion coefficient as a function of tantalum content (x), and it was found that the phase transition temperature increased with increasing the tantalum content, being T=561, 634, and 802 °C for x=0.1, 0.2, and 0.4, respectively. The electrical conductivity of SLNT was measured by electrochemical impedance spectroscopy as a function of temperature and tantalum concentration under wet (pH2O of about 0.03 atm) Ar atmosphere. At each temperature, the conductivity decreased with increasing the tantalum content, at 600 °C being 2.68×10−4, 3.14×10−5, and 5.41×10−6 Scm−1 for the x=0.1, 0.2, and 0.4 compositions, respectively. SLNT with x=0.2 shows a good compromise between proton conductivity and the requirement of avoiding detrimental phase transitions for application as a thin-film electrolyte below 600 °C.
2012
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore CHIM/07 - FONDAMENTI CHIMICI DELLE TECNOLOGIE
English
Con Impact Factor ISI
Niobate, Tantalate, Electrolyte, SOFC, Proton conductivity
www.elsevier .com/locate/ssi
Santibanez Mendieta, A., Fabbri, E., Licoccia, S., Traversa, E. (2012). Tailoring phase stability and electrical conductivity of Sr0.02La0.98Nb1–xTaxO4 for intermediate temperature fuel cell proton conducting electrolytes. SOLID STATE IONICS, 216, 6-10 [10.1016/j.ssi.2011.09.019].
Santibanez Mendieta, A; Fabbri, E; Licoccia, S; Traversa, E
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/76228
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