Conductivity and stability of cobalt pyrovanadate

Peter I. Cowin, Rong Lan, C. T G Petit, Lei Zhang, Shanwen Tao

Research output: Contribution to journalArticle

Abstract

Cobalt pyrovanadate was successfully synthesised by a solid state route and the conductivity in both oxidising and reducing environments was determined for the first time. Impedance measurements between 300 °C and 700 °C in air determined that Co2V2O7 is an intrinsic semiconductor with activation energy of 1.16(3) eV. The conductivity in air reached a maximum of 4 × 10-4 S cm-1 at 700 °C. Semiconducting behaviour was also observed in 5% H2/Ar, albeit with a much smaller activation energy of 0.04(4) eV. Between 300 °C and 700 °C the conductivity ranged from 2.45 S cm-1 to 2.68 S cm-1, which is approaching the magnitude required for SOFC anode materials. Thermogravimetric analysis found a significant weight loss upon reduction of the compound. X-ray diffraction analysis, coupled with data from previous research, suggested compound degradation into Co2-xV1+xO 4, CoO and VO. The redox instability and the low conductivity lead us to the conclusion that cobalt pyrovanadate is unsuitable for utilisation as an anode material for SOFCs although the conductivity is reasonable in a reducing atmosphere. © 2011 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)4117-4121
Number of pages5
JournalJournal of Alloys and Compounds
Volume509
Issue number10
DOIs
Publication statusPublished - 10 Mar 2011

Fingerprint

Cobalt
Solid oxide fuel cells (SOFC)
Anodes
Activation energy
Air
X ray diffraction analysis
Thermogravimetric analysis
Semiconductor materials
Degradation
Oxidation-Reduction

Keywords

  • Anode
  • Cobalt pyrovanadate
  • Conductivity
  • Solid oxide fuel cell

Cite this

Cowin, P. I., Lan, R., Petit, C. T. G., Zhang, L., & Tao, S. (2011). Conductivity and stability of cobalt pyrovanadate. Journal of Alloys and Compounds, 509(10), 4117-4121. https://doi.org/10.1016/j.jallcom.2010.12.166
Cowin, Peter I. ; Lan, Rong ; Petit, C. T G ; Zhang, Lei ; Tao, Shanwen. / Conductivity and stability of cobalt pyrovanadate. In: Journal of Alloys and Compounds. 2011 ; Vol. 509, No. 10. pp. 4117-4121.
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Cowin, PI, Lan, R, Petit, CTG, Zhang, L & Tao, S 2011, 'Conductivity and stability of cobalt pyrovanadate', Journal of Alloys and Compounds, vol. 509, no. 10, pp. 4117-4121. https://doi.org/10.1016/j.jallcom.2010.12.166

Conductivity and stability of cobalt pyrovanadate. / Cowin, Peter I.; Lan, Rong; Petit, C. T G; Zhang, Lei; Tao, Shanwen.

In: Journal of Alloys and Compounds, Vol. 509, No. 10, 10.03.2011, p. 4117-4121.

Research output: Contribution to journalArticle

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