INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
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IF 7.139
Zhenwei Wang,Shikai Zhao,Xue Guo,Jiao Li,Qiangqiang Hu,Yurun Feng,Fangyong Yu,Haibin Sun
La 0·6 Sr 0·4 Co 0·2 Fe 0·8 O 3-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 ( R p ) of LSCF cathodes changes from 0.26 Ω cm 2 to 0.62 Ω cm 2 at 700 °C, while that of LSCF-Ag cathodes shows nearly no change (from 0.24 Ω cm 2 to 0.26 Ω cm 2 at 700 °C). In LSCF-Ag cathodes, the formation of AgCrO 2 instead of SrCrO 4 avoids the lack of excessive Sr in the A site of LSCF, and AgCrO 2 has an electronic conductivity two orders of magnitude greater than SrCrO 4 , 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.
研究领域:
材料科学
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能源工程
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DOI
高影响因子
Nano Research
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2021
·Vol. 15
·期 4
·3264-3272
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IF 8.897
Cai Changkun,Xie Manyi,Xue Ke,Shi Yu,Li Shuting,Liu Yuanyuan,An Shengli,Yang Hong
La 06 Sr 04 Co 02 Fe 08 O 3− δ (LSCF) is recognized as one of the most promising cathode materials for the highly-desired intermediate-temperature solid oxide fuel cell (IT-SOFC) technology. However, it is still challenged by polarization losses due to reduced operation temperatures. In this work, a series of Ba 2+ -doped La 0.6− x Ba x Sr 0.4 Co 0.2 Fe 0.8 O 3− δ (LBSCF x, x = 0.05, 0.10, 0.15, and 0.20) materials are successfully synthesized and their electrochemical performances are evaluated as a cathode for IT-SOFC technology. The study shows that, compared to the un-doped LSCF, the Ba 2+ -doped LBSCF possess higher electrical conductivities at 500–800 °C and display lower polarization resistances to oxygen adsorption/dissociation. As a result, the Ni-SDC|SDC|LBSCF0.20 cell (SDC = samarium-doped cerium, Sm 0.2 Ce 0.8 O 1.9 ) delivers a high maximum power density of 0.704 W/cm 2 at 750 °C, which is > 30% higher than the Ni-SDC|SDC|LSCF cell. This work reveals that Ba 2+ -doping is effective in enhancing oxygen catalytic activity of LSCF-based cathode materials, demonstrating a new and commercial-feasible strategy in developing high performance cathode materials for the IT-SOFC technology.
研究领域:
材料科学
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能源技术
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DOI
高影响因子
Journal of Materials Chemistry A
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2023
·Vol. 11
·期 29
·15760-15768
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IF 11.9
Chunyan Xiong,Shan Xu,Xiantao Li,Tong Liu,Yuan Tan,Pei Zhao,Peng Qiu
The sluggish oxygen reduction reaction (ORR) kinetics and the fast performance degradation caused by Cr-poisoning greatly hinder the commercialisation of an LaxSr1–xCoyFe1–yO3–θ (LSCF) cathode in solid oxide fuel cells (SOFCs). Herein, a surface regulating and hetero-interface engineering method by chemical vapour deposition (CVD) was applied to construct a CeO2-coated LSCF cathode with enhanced ORR activity and durability. By controlling the CVD operating time, and the thickness of the CeO2 coating, the CeO2/LSCF heterointerface could be precisely engineered. With the optimal CVD time of 7 min, the x-LSCF cathode exhibited a minimal polarisation resistance (Rp) value of 0.11 Ω cm2 at 750 °C, which is almost one-fifth of that of an LSCF cathode (0.46 Ω cm2). Moreover, the CeO2-coated LSCF cathode exhibited a much lower degradation rate than the LSCF cathode in the long-term Cr-poisoning test. The improved ORR catalytic activity and durability of the CeO2-coated LSCF cathode were also verified in the single-cell mode. This study provides a comprehensive and novel strategy for tailoring the surface of the SOFC cathode for achieving enhanced performance and Cr-tolerance.
研究领域:
材料科学
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能源工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Jin Li,Xin Zhou,Congcong Wu,Li Zhao,Binghai Dong,Shimin Wang,Bo Chi
Challenged by the surface strontium (Sr) enrichment, long-term stability of the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) cathode remains to be the most intractable problem hindering its further development and application in solid oxide fuel cells (SOFCs). To enhance the durability and performance of LSCF-based electrodes, we propose a novel approach by introducing a highly active A-site deficient La 0.95 CoO 3-δ (LC95) thin film onto the surface of the porous LSCF scaffold, simultaneously working as the accepter for Sr diffusion and conformal collector for electrons conduction. Besides the inhibiting effect from the dense coating, the A-site deficiencies reserved in coating lattice enable promising stabilization for Sr diffusion and segregation. At 700 °C, the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ @La 0.95 CoO 3-δ (LSCF@LC95) hybrid cathode shows a polarization resistance of 0.28 Ωcm 2 , much lower than that for pristine LSCF cathode (0.36 Ωcm 2 ). In addition to the higher electrochemical activity, single cell with LSCF@LC95 cathode exhibits remarkable long-term stability without detectable degradation over 120 h.
研究领域:
材料科学
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电化学
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能源工程
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DOI
高影响因子
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