Chromium poisoning in (La,Sr)MnO3 cathode: Three-dimensional simulation of a solid oxide fuel cell

JOURNAL OF POWER SOURCES

卷:326

Article

Miyoshi, Kota¹  Iwai, Hiroshi¹  Kishimoto, Masashi¹  Saito, Motohiro¹  Yoshida, Hideo¹ 

[1] Kyoto Univ, Dept Aeronaut & Astronaut, Kyoto 6158540, Japan

关键词: Solid oxide fuel cells;    Chromium poisoning;    Triple-phase boundary;    Numerical simulation;   

DOI  :  10.1016/j.jpowsour.2016.06.110

来源: Elsevier

【 摘 要 】

A three-dimensional numerical model of a single solid oxide fuel cell (SOFC) considering chromium poisoning on the cathode side has been developed to investigate the evolution of the SOFC performance over long-term operation. The degradation model applied in the simulation describes the loss of the cathode electrochemical activity as a decrease in the active triple-phase boundary (TPB) length. The calculations are conducted for two types of cell: lanthanum strontium manganite (LSM)/yttria-stabilized zirconia (YSZ)/Ni-YSZ and LSM-YSZ/YSZ/Ni-YSZ. Their electrode microstructures are acquired by imaging with a focused ion beam scanning-electron microscope (FIB-SEM). The simulation results qualitatively reproduce the trends of chromium poisoning reported in the literature. It has been revealed that the performance degradation by chromium is primarily due to an increase in the cathode activation over potential. In addition, in the LSM-YSZ composite cathode, TPBs in the vicinity of the cathode electrolyte interface preferentially deteriorate, shifting the active reaction site towards the cathode surface. This also results in an increase in the cathode ohmic loss associated with oxide ion conduction through the YSZ phase. The effects of the cell temperature, the partial pressure of steam at the chromium source, the cathode microstructure, and the cathode thickness on chromium poisoning are also discussed. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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