Inhibition of chromium poisoning in La0·6Sr0·4Co0·2Fe0·8O3-δ cathode via simple electroless silver plating for solid oxide fuel cells

• Published in: International journal of hydrogen energy Vol. 47; no. 21; pp. 11250 - 11260
• Main Authors: Wang, Zhenwei, Zhao, Shikai, Guo, Xue, Li, Jiao, Hu, Qiangqiang, Feng, Yurun, Yu, Fangyong, Sun, Haibin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 08.03.2022
• Subjects: Cathode; Cr poisoning; Electroless plating; LSCF; Solid oxide fuel cell; LSCF; Cr poisoning; Cathode; Solid oxide fuel cell; Electroless plating
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.01.157

La0·6Sr0·4Co0·2Fe0·8O3-δ (LSCF), one kind of state-of-art solid oxide fuel cells (SOFCs) cathodes, often suffers from the chromium poisoning in the operating condition with Cr-based stainless steel interconnects, resulting in deteriorating cell performances. A simple electroless silver plating method was used to modify the surface of LSCF cathodes (named LSCF-Ag), and the anti-chromium stability of LSCF cathodes was studied. After the Cr treatment for 40 h, the polarization resistance (Rp) of LSCF cathodes changes from 0.26 Ω cm2 to 0.62 Ω cm2 at 700 °C, while that of LSCF-Ag cathodes shows nearly no change (from 0.24 Ω cm2 to 0.26 Ω cm2 at 700 °C). In LSCF-Ag cathodes, the formation of AgCrO2 instead of SrCrO4 avoids the lack of excessive Sr in the A site of LSCF, and AgCrO2 has an electronic conductivity two orders of magnitude greater than SrCrO4, thereby exhibiting significant survivability to Cr. The single cell with LSCF-Ag cathodes after Cr treatment shows a stable peak powder density of 288 mW cm−2 at 700 °C while taking wet hydrogen and air as fuel and oxidizer. As a comparison, the peak power density of single cells with blank LSCF cathodes drops by 12%. It is suggested that the simple electroless silver plating on LSCF cathodes is an effective method to suppress cathode chromium poisoning. [Display omitted] •Ag modified LSCF cathodes are synthesized by the simple electroless plating.•Ag loaded on the LSCF cathode can preferentially react with Cr to form AgCrO2.•Ag modified LSCF cathodes show excellent resistance and stability to chromium.