Chemical Stability and Electrochemical Properties of Perovskite Based Composite Electrolytes with High Ionic Conductivity

Abstract

Composite electrolytes consisting of protonic conducting perovskite oxide Sr(Y_0.08Zr_0.92)O_3-d and Sr(Gd_0.1Ce_0.9)O_3-d (SYZS and SGDC)  and alkaline carbonate (Li₂CO₃:Na₂CO₃, 1:1 molar ratio) were prepared through high energy milling followed by sintering techniques. The chemical and microstructural stability of these perovskite oxides with the mixed carbonates were studied by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) after reacting them at 690 °C for 1 h in air. The electrochemical performance of selected composites was evaluated using impedance spectroscopy in air. Among the two compositions, SrGdCeO₃ shows degradation in contact with molten carbonates whereas SrYZrO₃ is more stable. The corresponding composites have ionic conductivities (3.3x10^-1 Scm^-1 at 580 °C, in air) close to those reported for state-of-the-art ceria-based composite electrolytes. SrYZrO₃+Li₂CO₃:Na₂CO₃ composites show chemical stability at operating temperatures in the order of 600 °C, standing as a potential candidate for intermediate temperature applications.

Keywords

Composite electrolytes, Electrical conductivity, Perovskites, Intermediate temperature

References

1. Hui S, Roller J, Yick S, Zhang X, Dec`es-Petit C, Xie Y, Maric R, Ghosh D, A brief review of the ionic conductivity enhancement for selected oxide electrolytes, J. Power Sources 2007, 172,493-502
2. Stambouli A. B, Traversa E, Solid oxide fuel cells (SOFCs): a review of an environmentally clean and efficient source of energy, Renewable and Sustainable Energy Reviews, 2002, 6, 433–455
3. Liangdong Fan, Chengyang Wang, Mingming Chen, Bin Zhu, Recent development of ceria-based (nano)composite materials for low temperature ceramic fuel cells and electrolyte-free fuel cells, J Power Sources. 234 (2013) 154-174
4. Bin Zhu , Solid oxide fuel cell (SOFC) technical challenges and solutions from nano-aspects. Int. J. Energy Res. 2009; 33:1126–1137
5. B. Zhu, X.T. Yang, J. Xu, Z.G. Zhu , S.J. Ji , M.T. Sun , J.C. Sun Innovative low temperature SOFCs and advanced materials, J Power Sources 118 (2003) 47–53
6. Surendran Rajesh, Daniel A. Macedo, Rubens M. Nascimento, Graziele L. Souza, Filipe M.L. Figueiredo, Fernando M.B. Marques, One-step synthesis of composite electrolytes of Eu-doped ceria and alkali metal carbonates, , Int. J Hydrog Energy 38 (2013) 16539 -16545
7. Francisco J. A. Loureiro, Surendran Rajesh, Filipe M. L. Figueiredo and Fernando M. B. Marques Stability of metal oxides against Li/Na carbonates in composite electrolytes, RSC Adv., 2014, 4, 59943
8. Matthew Anderson, Y.S. Lin, Carbonate–ceramic dual-phase membrane for carbon dioxide separation, J Membrane Science 357 (2010) 122–129
9. J.K. Thomas, H. Padma Kumar, R. Pazhani, S. Solomon, R. Jose, J. Koshy, Synthesis of strontium zirconate as nanocrystals through a single step combustion process, Mater. Lett. 61 (2007) 1592–1595
10. Fellipe Sartorida Silva, Teófilo Miguelde Souza, Novel materials for solid oxide fuel cell technologies: A literature review, Inter. J Hydrogen Energy, 42(41), 2017, 26020-26036.
11. Ana Sofia Valente Ferreira, Thangavelo Saradha, Filipe Lebre Figueiredo, Fernando Manuel Bico Marques, Microstructural effects in composite electrolytes for fuel cells 35(12), 2011, 1090-1099
12. Amjad Ali, Asia Rafique, Muhammad Kaleemullah, Ghazanfar Abbas, M. Ajmal Khan, M. Ashfaq Ahmad, Rizwan Raza, Effect of Alkali Carbonates (Single, Binary, and Ternary) on Doped Ceria: A Composite Electrolyte for Low-Temperature Solid Oxide Fuel Cells, ACS Appl. Mater. Interfaces 2018, 10(1), 806–818
13. Ana I.B.Rondão, Sónia G.Patrício, Filipe M.L.Figueiredo, Fernando M.B.Marques, Composite electrolytes for fuel cells: Long-term stability under variable atmosphere, Inter J Hydrogen Energy, 39(10), 2014, 5460-5469