In-situ growth of metallic nanoparticles on perovskite parent as a hydrogen electrode for solid oxide cells

JOURNAL OF POWER SOURCES

卷:405

Article

Wang, Yao¹  Lei, Xueling²  Zhang, Yanxiang³  Chen, Fanglin⁴  Liu, Tong^1,5 

[1] Wuhan Univ, Sch Power & Mech Engn, Minist Educ, Key Lab Hydraul Machinery Transients, Wuhan 430072, Hubei, Peoples R China

[2] Jiangxi Normal Univ, Dept Phys, Nanchang 330022, Jiangxi, Peoples R China

[3] Harbin Inst Technol, Sch Mat Sci & Engn, Natl Key Lab Precis Hot Proc Met, Harbin 150001, Heilongjiang, Peoples R China

[4] Univ South Carolina, Dept Mech Engn, Columbia, SC 29208 USA

[5] Wuhan Univ, Suzhou Inst, Suzhou 215123, Jiangsu, Peoples R China

关键词: In-situ exsolution;    Hydrogen electrode;    Solid oxide cell;    Steam electrolysis;    Perovskite;   

DOI  :  10.1016/j.jpowsour.2018.10.023

来源: Elsevier

【 摘 要 】

In this work, in-situ fabricated nano-socketed Fe-Ni particles structured Sr2Fe1.5Mo0.05O6-delta (SFM) electrodes are proposed to simultaneously combine good electrochemical properties of Ni-based materials and good stabilities of SFM-based materials. Preliminary studies on the Ellingham diagram and density functional theory offer certain theoretical basis for realizing the feasibility to extract Fe-Ni alloy from parent Sr2Fe1.3Ni0.2Mo0.5O6.(delta) in the viewpoint of thermodynamic and minimum energy principle. Experimental results according to X-ray diffraction, scanning electron microscopy-elements mapping, high resolution transmission electron microscopy measurements show that a large amount of uniformly dispersed Fe-Ni nano-catalysts are elegantly exsolved from the perovskite oxide parent. Electrical conductivity relaxation results indicate that surface exchange coefficient of SFM-based material is enhanced from 0.5 x 10(-3) to 1.7 x 10(-3) cms(-1) by the in-situ growth of Fe-Ni alloy at 800 degrees C. The in -situ fabricated Fe-Ni@SFM combined with Ce0.8Sm0.2O1.9 (SDC) composite electrodes perform a considerably high electrolysis current density of 1257 mA cm(-2) at 1.3 V, 850 degrees C and polarization resistance of 0.20 Omega cm(2) at open circuit voltage and 850 degrees C. Distribution relaxation of time analysis of impedance spectra shows that the gas conversion process is the rate-limiting step in the Fe-Ni@SFM-SDC hydrogen electrode for steam electrolysis.

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