Study on the Conductivity of La_0.4Sr_1.6CoNbO_6-δ as an Electrode Material for Symmetrical SOFC

Abstract:

The double-perovskite La_0.4Sr_1.6CoNbO_6-δ (LSCN) powders were synthesized by the solid-state reaction method. The electrical conductivities of LSCN samples were tested in air and 5 vol%H₂/Ar. The results show that the conductivity of LSCN in 5 vol%H₂/Ar (8.12 Scm^-1) at 850 °C was higher than that in air (7.03 Scm^-1). The activation energy obtained from the Arrhenius function was 0.821 eV in air and 0.707 eV in 5 vol%H₂/Ar. The analysis of XPS shows that there exit three valence states of Co (Co⁺², Co⁺³, Co⁺⁴) and two of Nb (Nb⁺⁴, Nb⁺⁵). The loss of lattice oxygen in LSCN not only produces oxygen vacancies, but also generates excess electrons, which contributes to the electrical conductivity of the LSCN samples.

• Periodical: Key Engineering Materials (Volumes 602-603)
• Pages: 858-861
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.602-603.858
• Online since: March 2014
• Authors: Jiang Tao Zhou, Xu Ping Lin*, De Sheng Ai, Ben Ge, Zhi Jian Peng
• Keywords: Conductivity, Double-Perovskite, Electrode Materials, SOFC

References

[1] R M Ormerod. J. Chem. Soc. Rev. 32 (2003) 17-28.

[2] X M Ge, S H Chan, Q L Liu, Q Sun. J. Adv. Energy Mater. 10 (2012) 1156-1181.

[3] David M B, Tao S W, John T S. J. Mater. Chem. 16 (2006) 1603-1605.

[4] Q Liu, X H Dong, G L Xiao. J. Adv. Mate. 22 (2010) 5478-5482.

[5] G Kim, S Wang, A J Jacobson. J. Mater. Chem. 17 (2007) 2500–2505.

[6] Y H Huang, G Liang, J. Chem. Mater. 21 (2009) 2319–2326.

[7] Z X Xie H L Zhao, Z H Du. J. Phys. Chem. 116 (2012) 9763-9743.

[8] Z Shao, S M Haile. Nature. 43 (2004) 170-173.

[9] A B Munoz, M Pavone, E A Carter. Chem. Mater. 23 (2011) 4525-4536.

[10] S W Tao, C V Jesus, T S I John. Chem. Mater. 16 (2004) 2309-2316.

[11] F J Jin, Y Shen, R Wang, He T M. J. Power Sources. 234 (2013) 244-251.

[12] Lozano, Q Y Chen, P V Wadekar. J. Solar Energy Material & Solar Cells. 113 (2013) 171-178.

[13] X Pan, Z B Wang, B B He, Wang S R. Int. J. Hydrogen Energy. 38 (2013) 4108-4115.

[14] B A Sonia, T G Octavio. J. super. Nov. Magn. 26 (2013) 3171-3180.

[15] B B He, L Zhao, S X Song. J. Electrochem. Soc. 159 (2012) B619-B626.

[16] Z Maupoey, M T Azcondo, U Anador. J. Mater. Chem. 22 (2012) 18033-18042.