材料科学
氧化钇稳定氧化锆
阳极
电化学
氧化物
电极
电解质
固体氧化物燃料电池
微观结构
复合数
三相边界
扫描电子显微镜
复合材料
电导率
立方氧化锆
化学工程
分析化学(期刊)
冶金
化学
陶瓷
色谱法
工程类
物理化学
作者
Amit Das,Sunil Kumar,Biswajit Jana,M. Buchi Suresh,Prashanthi Chalavadi,Shobit Omar
出处
期刊:ACS applied energy materials
[American Chemical Society]
日期:2022-01-19
卷期号:5 (2): 1607-1617
被引量:5
标识
DOI:10.1021/acsaem.1c03029
摘要
The electrochemical performance of porous composites of Gd0.1Ce0.9O2−δ/SrMg0.1Mo0.9O3−δ is investigated for the anode application under a typical fuel environment of solid oxide fuel cells (SOFCs). Nanosized powder of SrMg0.1Mo0.9O3−δ possessing a cubic perovskite phase is synthesized using the solution-combustion method. Composites having the composition of xGd0.1Ce0.9O2−δ/SrMg0.1Mo0.9O3−δ (where x is a weight fraction of Gd0.1Ce0.9O2−δ ranging from 0.5 to 0.8) are prepared using a traditional mixing method. At 850 °C, the DC electrical conductivity of SrMg0.1Mo0.9O3−δ under moist 20% H2/N2 is 617 S·cm–1 which declines to ∼105 S·cm–1 for 0.6Gd0.1Ce0.9O2−δ/SrMg0.1Mo0.9O3−δ. Symmetric cells are fabricated using dense disks of yttria-stabilized zirconia as an electrolyte with a thin Gd0.1Ce0.9O2−δ buffer layer coated on both faces. An optimized slurry of the composite electrode is blade-coated on the dense buffer layer and subsequently sintered at 950 °C in air. Scanning electron microscopy reveals a porous microstructure with an electrode layer thickness of ∼14 μm. A single-phase SrMg0.1Mo0.9O3−δ electrode exhibits an area-specific resistance of 0.28 Ω·cm2, which is less than 6 times the value offered by undoped SrMoO3 at 800 °C in 3% H2O/H2. The optimum Gd0.1Ce0.9O2−δ addition (x = 0.7) to SrMg0.1Mo0.9O3−δ resulted in a significantly low area-specific resistance of 0.09 Ω·cm2 at 800 °C. The performance of the optimized electrode composite is also evaluated by modifying the microstructure of the Gd0.1Ce0.9O2−δ buffer layer. Interestingly, the symmetrical cell with a porous buffer layer further reduces the electrode area-specific resistance to 0.065 Ω·cm2. The observed results are ascribed to the penetration of electrocatalyst SrMg0.1Mo0.9O3−δ particles inside the porous buffer layer during the blade-coating. This possibly extends the triple-phase boundary length and facilitates the charge-transfer reaction. The electrochemical performance attained in the present study is far superior to the other Ni-free ceramic anodes reported earlier, which highlights the promise of 0.7Gd0.1Ce0.9O2−δ/SrMg0.1Mo0.9O3−δ for the SOFC anode.
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