A Stable and Efficient Cathode for Fluorine-Containing Proton-Conducting Solid Oxide Fuel Cells

Yun Xie; Nai Shi; Daoming Huan; Wenzhou Tan; Junfa Zhu; Xusheng Zheng; Haibin Pan; Ranran Peng; Changrong Xia

doi:10.1002/cssc.201801193

A Stable and Efficient Cathode for Fluorine-Containing Proton-Conducting Solid Oxide Fuel Cells

ChemSusChem. 2018 Oct 11;11(19):3423-3430. doi: 10.1002/cssc.201801193. Epub 2018 Aug 20.

Authors

Yun Xie¹, Nai Shi¹, Daoming Huan¹, Wenzhou Tan¹, Junfa Zhu², Xusheng Zheng², Haibin Pan², Ranran Peng^{1

3

4}, Changrong Xia¹

Affiliations

¹ CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, No.96 Jinzhai Road, Hefei, Anhui Province, 230026, P. R. China.
² National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China.
³ Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
⁴ Hefei National Laboratory of Physical Science at the Microscale, University of Science and Technology of China, Hefei, 230026, Anhui, China.

PMID: 30058140
DOI: 10.1002/cssc.201801193

Abstract

Substitution of anions such as F^- and Cl^- can effectively improve the stability of proton-conducting electrolytes at no expense to proton conduction. However, during operation, F^- and Cl^- in electrolytes can transfer to the cathodes, which reduces the stability of the electrolytes. In this work, F^- -doped Ba_0.5 Sr_0.5 Co_0.8 Fe_0.2 O_3-δ [Ba_0.5 Sr_0.5 Co_0.8 Fe_0.2 O_2.9-δ F_0.1 (F-BSCF)] was prepared as a potential cathode for proton-conducting solid oxide fuel cells with BaCe_0.8 Sm_0.2 F_0.1 O_2.85 electrolyte. The incorporation of F^- in the cathode depressed F^- diffusion from the electrolyte and improved the stability of button cells. Temperature-changing X-ray photoelectron spectroscopy and electronic conductivity relaxation results demonstrated that the incorporation of F^- enhanced the oxygen incorporation kinetics at intermediate temperatures and improved the cathode catalytic performance. Moreover, a button cell prepared with this novel cathode was stable for 270 h at a current density of 300 mA cm^-2 and 700 °C, which was much superior than those containing a BSCF cathode.

Keywords: anion doping; electrochemistry; fuel cells; solid oxide fuel cells; stability.

Abstract

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