The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Zhongliang Zhan - One of the best experts on this subject based on the ideXlab platform.
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Shape-Dependent Activity of Ceria for Hydrogen Electro-Oxidation in Reduced-Temperature Solid Oxide Fuel Cells.
Small (Weinheim an der Bergstrasse Germany), 2015Co-Authors: Xiaofeng Tong, Xuejiao Liu, Ting Luo, Xie Meng, Jianqiang Wang, Chusheng Chen, Zhongliang ZhanAbstract:Single crystalline ceria nanooctahedra, nanocubes, and nanorods are hydrothermally synthesized, colloidally impregnated into the porous La0.9Sr0.1Ga0.8Mg0.2O3- (LSGM) scaffolds, and electrochemically evaluated as the anode catalysts for Reduced Temperature solid oxide fuel cells (SOFCs). Well-defined surface terminations are confirmed by the high-resolution transmission electron microscopy (111) for nanooctahedra, (100) for nanocubes, and both (110) and (100) for nanorods. Temperature-programmed reduction in H-2 shows the highest reducibility for nanorods, followed sequentially by nanocubes and nanooctahedra. Measurements of the anode polarization resistances and the fuel cell power densities reveal different orders of activity of ceria nanocrystals at high and low Temperatures for hydrogen electro-oxidation, i.e., nanorods > nanocubes > nanooctahedra at T 450 degrees C and nanooctahedra > nanorods > nanocubes at T 500 degrees C. Such shape-dependent activities of these ceria nanocrystals have been correlated to their difference in the local structure distortions and thus in the reducibility. These findings will open up a new strategy for design of advanced catalysts for Reduced-Temperature SOFCs by elaborately engineering the shape of nanocrystals and thus selectively exposing the crystal facets.
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A micro-nano porous oxide hybrid for efficient oxygen reduction in Reduced-Temperature solid oxide fuel cells
Scientific reports, 2012Co-Authors: Da Han, Xuejiao Liu, Fanrong Zeng, Jiqin Qian, Zhongliang ZhanAbstract:A micro-nano porous oxide hybrid for efficient oxygen reduction in Reduced-Temperature solid oxide fuel cells
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A Reduced Temperature solid oxide fuel cell with nanostructured anodes
Energy & Environmental Science, 2011Co-Authors: Zhongliang Zhan, David M. Bierschenk, J. Scott Cronin, Scott A. BarnettAbstract:Reduced-Temperature solid oxide fuel cells (SOFCs), featuring thin strontium- and magnesium-doped lanthanum gallate (LSGM) electrolytes and nano-scale Ni anodes, showed high power densities of 1.20 W cm−2 at 650 °C and 0.39 W cm−2 at 550 °C when operated on humidified hydrogen fuel and air oxidant.
Scott A. Barnett - One of the best experts on this subject based on the ideXlab platform.
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solid oxide cells with zirconia ceria bi layer electrolytes fabricated by Reduced Temperature firing
Journal of Materials Chemistry, 2015Co-Authors: Zhan Gao, V Y Zenou, David Kennouche, Laurence Marks, Scott A. BarnettAbstract:Anode-supported solid oxide cells (SOCs) with thin bi-layer Y0.16Zr0.92O2−δ (YSZ)/Gd0.1Ce0.9O1.95 (GDC) electrolytes were prepared by a Reduced-Temperature (1250 °C) co-firing process enabled by the addition of a Fe2O3 sintering aid. The Fe2O3 amounts in the layers affected the formation of voids at the GDC/YSZ interface; the case with 1 mol% Fe2O3 in the YSZ layer and 2 mol% Fe2O3 in the GDC layer yielded minimal interfacial voids, presumably because of optimized shrinkage matching between the electrolyte layers during co-firing. The best cells yield fuel cell power density at 0.7 V in air and humidified hydrogen of 1.74 W cm−2 (800 °C) and 1.0 W cm−2 (700 °C). Under electrolysis conditions, i.e., air and 50 vol% H2O–50 vol% H2, the best cell area specific resistance is 0.12 Ω cm2 at 800 °C and 0.27 Ω cm2 at 700 °C. This excellent cell performance was explained by a number of factors related to the Reduced firing Temperature: (1) low electrolyte resistance due to minimization of YSZ/GDC interdiffusion; (2) minimal zirconate phase formation between the YSZ and the La0.6Sr0.4Fe0.8Co0.2O3 (LSFC) cathode because of the dense GDC barrier layer; (3) high three phase boundary density in the Ni–YSZ anode functional layer; and (4) good pore connectivity in the Ni–YSZ support. Preliminary life testing under fuel cell and electrolysis operation shows promising cell stability.
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A Reduced Temperature solid oxide fuel cell with nanostructured anodes
Energy & Environmental Science, 2011Co-Authors: Zhongliang Zhan, David M. Bierschenk, J. Scott Cronin, Scott A. BarnettAbstract:Reduced-Temperature solid oxide fuel cells (SOFCs), featuring thin strontium- and magnesium-doped lanthanum gallate (LSGM) electrolytes and nano-scale Ni anodes, showed high power densities of 1.20 W cm−2 at 650 °C and 0.39 W cm−2 at 550 °C when operated on humidified hydrogen fuel and air oxidant.
L. C. De Jonghe - One of the best experts on this subject based on the ideXlab platform.
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Reduced Temperature solid oxide fuel cell based on ysz thin film electrolyte
Journal of The Electrochemical Society, 1997Co-Authors: S. De Souza, S.j. Visco, L. C. De JongheAbstract:A planar thin-film solid oxide fuel cell has been fabricated with an inexpensive, scalable, technique involving colloidal deposition of yttria-stabilized zirconia (YSZ) films on porous NiO-YSZ substrates, yielding solid oxide fuel cells capable of exceptional power density at operating Temperatures of 700 to 800°C. The thickness of the YSZ film deposited onto the porous substrate is approximately 10 Rim after sintering, and is well bonded to the NiO/YSZ substrate. Ni-YSZ/YSZ/LSM cells built with this technique have exhibited theoretical open-circuit potentials (OCPs), high current densities, and exceptionally good power densities of over 1900 mW/cm 2 at 800°C. Electrochemical characterization of the cells indicates negligible losses across the Ni-YSZ/YSZ interface and minor polarization of the fuel electrode. Thinfilm cells have been tested for long periods of time (over 700 h) and have been thermally cycled from 650 to 800°C while demonstrating excellent stability over time.
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Thin-film electrolytes for Reduced Temperature solid oxide fuel cells
MRS Proceedings, 1994Co-Authors: S.j. Visco, L.s. Wang, S. De Souza, L. C. De JongheAbstract:Solid oxide fuel cells produce electricity at very high efficiency and have very low to negligible emissions, making them an attractive option for power generation for electric utilities. However, conventional SOFC`s are operated at 1000{degrees}C or more in order to attain reasonable power density. The high operating Temperature of SOFC`s leads to complex materials problems which have been difficult to solve in a cost-effective manner. Accordingly, there is much interest in reducing the operating Temperature of SOFC`s while still maintaining the power densities achieved at high Temperatures. There are several approaches to Reduced Temperature operation including alternative solid electrolytes having higher ionic conductivity than yttria stabilized zirconia, thin solid electrolyte membranes, and improved electrode materials. Given the proven reliability of zirconia-based electrolytes (YSZ) in long-term SOFC tests, the use of stabilized zirconia electrolytes in Reduced Temperature fuel cells is a logical choice. In order to avoid compromising power density at intermediate Temperatures, the thickness of the YSZ electrolyte must be Reduced from that in conventional cells (100 to 200 {mu}m) to approximately 4 to 10 {mu}m. There are a number of approaches for depositing thin ceramic films onto porous supports including chemical vapor deposition/electrochemical vapor deposition, sol-gel deposition, sputter deposition,more » etc. In this paper we describe an inexpensive approach involving the use of colloidal dispersions of polycrystalline electrolyte for depositing 4 to 10 {mu}m electrolyte films onto porous electrode supports in a single deposition step. This technique leads to highly dense, conductive, electrolyte films which exhibit near theoretical open circuit voltages in H{sub 2}/air fuel cells. These electrolyte films exhibit bulk ionic conductivity, and may see application in Reduced Temperature SOFC`s, gas separation membranes, and fast response sensors.« less
Meilin Liu - One of the best experts on this subject based on the ideXlab platform.
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Reduced Temperature solid oxide fuel cells fabricated by screen printing
Electrochemical and Solid State Letters, 2001Co-Authors: Changrong Xia, Fanglin Chen, Meilin LiuAbstract:Electrolyte films of samaria-doped ceria ~SDC, Sm0.2Ce0.8O1.9) are fabricated onto porous NiO-SDC substrates by a screen printing technique. A cathode layer, consisting of Sm0.5Sr0.5CoO3 and 10 wt % SDC, is subsequently screen printed on the electrolyte to form a single cell, which is tested at Temperatures from 400 to 600°C. When humidified ~3% H2O) hydrogen or methane is used as fuel and stationary air as oxidant, the maximum power densities are 188 ~or 78! and 397 ~or 304! mW/cm at 500 and 600°C, respectively. Impedance analysis indicates that the performances of the solid oxide fuel cells ~SOFCs! below 550°C are determined primarily by the interfacial resistance, implying that the development of catalytically active electrode materials is critical to the successful development of high-performance SOFCs to be operated at Temperatures below 600°C. © 2001 The Electrochemical Society. @DOI: 10.1149/1.1361158# All rights reserved.
Li Jian - One of the best experts on this subject based on the ideXlab platform.
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Heat resistant alloys as interconnect materials of Reduced Temperature SOFCs
Journal of Power Sources, 2006Co-Authors: Li Jian, Pu Jian, Xie Guang-yuan, Wang Shunxu, Xiao Jian-zhongAbstract:Abstract Heat-resistant alloys, Haynes 230 and SS310, were exposed to air and humidified H2 at 750 °C for up to 1000 h, respectively, simulating the environments in Reduced Temperature solid oxide fuel cells (SOFCs). The oxidized samples were characterized by using SEM, EDS and X-ray diffraction to obtain the morphology, thickness, composition and crystal structure of the oxide scales. A mechanism for the formation of metallic Ni-rich nodules on top of the oxide scale in Haynes 230 sample oxidized in humidified H2 was established. Thermodynamic analysis confirmed that MnCr2O4 is the favored spinel phase, together with Cr2O3, in the oxide scales.
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Oxidation of Haynes 230 alloy in Reduced Temperature solid oxide fuel cell environments
Journal of Power Sources, 2004Co-Authors: Li Jian, Pu Jian, Xiao Jian-zhong, Qian Xiao-liangAbstract:Abstract Haynes 230 alloy was exposed to reducing and oxidizing environments at 750 °C for 1000 h, simulating the conditions in a Reduced Temperature solid oxide fuel cell (SOFC). The oxidized specimens were characterized in terms of the oxide morphology, composition and crystal structure. The oxide scale in each environment was identified as Cr2O3 with the existence of Cr2MnO4. Ni remained metallic in the reducing atmosphere, and NiO was detected in the sample exposed to air. The oxide scale is around 1 μm thick after 1000 h of oxidation in both situations. The area specific resistance (ASR) contributed by the oxide scale is expected less than 0.1 Ω cm2 after 40,000 h of exposure when a parabolic oxide growth rate is assumed, demonstrating the suitability of the interconnect application of this alloy in the Reduced Temperature SOFCs.
