The Experts below are selected from a list of 142941 Experts worldwide ranked by ideXlab platform
Siew Hwa Chan - One of the best experts on this subject based on the ideXlab platform.
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solid oxide fuel cell Anode materials for direct hydrocarbon utilization
Advanced Energy Materials, 2012Co-Authors: Siew Hwa Chan, Qinglin Liu, Qiang SunAbstract:Solid oxide fuel cells (SOFC) are highly efficient energy conversion devices with the advantage of directly utilizing hydrocarbon fuels. Starting with a short introduction about the fuel challenges and early achievements in this field, this review paper focuses on advances in oxygen-ion conducting electrolyte-based SOFC during the last 15 years. Robust Anodes immune to carbon deposition are a prerequisite for direct hydrocarbon SOFC. In this paper, direct hydrocarbon SOFC Anode materials are classified into three general categories: Ni-cermet, Cu-cermet, and oxide-based Anodes. Oxide Anodes are further classified in terms of their crystalline structures, namely fluorite, rutile, tungsten bronze, pyrochlore, perovskite, and double perovskite. Achievements and recent advances on these SOFC Anodes are reviewed and discussed. The concluding remarks summarize the pros and cons of direct hydrocarbon SOFC Anode materials along with the perspective of future research trends.
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A review of Anode materials development in solid oxide fuel cells
Journal of Materials Science, 2004Co-Authors: San Ping Jiang, Siew Hwa ChanAbstract:High temperature solid oxide fuel cell (SOFC) has prospect and potential to generate electricity from fossil fuels with high efficiency and very low greenhouse gas emissions as compared to traditional thermal power plants. In the last 10 years, there has been significant progress in the materials development and stack technologies in SOFC. The objective of this paper is to review the development of Anode materials in SOFC from the viewpoint of materials microstructure and performance associated with the fabrication and optimization processes. Latest development and achievement in the Ni/Y_2O_3-ZrO_2 (Ni/YSZ) cermet Anodes, alternative and conducting oxide Anodes and Anode-supported substrate materials are presented. Challenges and research trends based on the fundamental understanding of the materials science and engineering for the Anode development for the commercially viable SOFC technologies are discussed.
Ralph G Nuzzo - One of the best experts on this subject based on the ideXlab platform.
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directed transport as a route to improved performance in micropore modified encapsulated multilayer silicon electrodes
Journal of The Electrochemical Society, 2013Co-Authors: Jason L Goldman, Michael W Cason, David J Wetzel, Henning Vieker, Andre Beyer, Armin Golzhauser, Andrew A Gewirth, Ralph G NuzzoAbstract:Energy storage is an increasingly critical component of modern technology, with applications that include energy infrastructure, transportation systems, and portable electronics. Improvements to lithium-ion battery energy/power density through the adoption of silicon Anodes promising both gravimetric and volumetric capacities that far exceed traditional carbon-based Anodes has been limited by similar to 300% strains and poor coulombic efficiency during charge and discharge ((dis)charge) cycling which result in short operational lifetimes. We examine encapsulated micropore-modified silicon Anodes that define lithium mass-transfer dynamics to constrain strain evolution and improve capacity retention during (dis)charge cycling. Fully integrated cells incorporating this silicon Anode and a commercial grade LiCoO2 cathode maintain their capacity for 110 cycles with >99% average coulombic efficiency from cycles 5 to 100. Anodes with thicknesses up to 50 mu m resulted in area-normalized capacities of up to 12.7 mAhcm(-2). When the silicon Anode microstructure pitch is varied, a direct relationship is found to exist between the rate capability and volumetric capacity of the Anode. Helium-ion Microscopy, Secondary Ion Mass Spectrometry, and Scanning Electron Microscopy, used as ex-situ characterization methods for the evolution of the electrode's structure on cycling, reveal significant changes in nanoscale morphology that otherwise retain the essential laminate micropore motif of the initial Si Anode. (C) 2013 The Electrochemical Society. All rights reserved.
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strain anisotropies and self limiting capacities in single crystalline 3d silicon microstructures models for high energy density lithium ion battery Anodes
Advanced Functional Materials, 2011Co-Authors: Jason L Goldman, Andrew A Gewirth, Brandon R Long, Ralph G NuzzoAbstract:This study examines the crystallographic anisotropy of strain evolution in model, single-crystalline silicon Anode microstructures on electrochemical intercalation of lithium atoms. The 3D hierarchically patterned single- crystalline silicon microstructures used as model Anodes were prepared using combined methods of photolithography and anisotropic dry and wet chemical etching. Silicon Anodes, which possesses theoretically ten times the energy density by weight compared to conventional carbon Anodes, reveal highly anisotropic but more importantly, variably recoverable crystallographic strains during cycling. Model strain-limiting silicon Anode architectures that mitigate these impacts are highlighted. By selecting a specific design for the silicon Anode microstructure, and exploiting the crystallographic anisotropy of strain evolution upon lithium intercalation to control the direction of volumetric expansion, the volume available for expansion and thus the charging capacity of these structures can be broadly varied. We highlight exemplary design rules for this self-strain-limited charging in which an Anode can be variably optimized between capacity and stability. Strain-limited capacities ranging from 677 mAhg-1 to 2833 mAhg-1 were achieved by constraining the area available for volumetric expansion via the design rules of the microstructures.
Karl Foger - One of the best experts on this subject based on the ideXlab platform.
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kinetics of internal steam reforming of methane on ni ysz based Anodes for solid oxide fuel cells
Catalysis Today, 2000Co-Authors: Khaliq Ahmed, Karl FogerAbstract:Abstract The kinetics of steam reforming of methane was determined on a Ni-YSZ Anode, which we refer to as Anode ‘A’ and on a Ni-YSZ Anode modified by the addition of a basic compound, which we refer to as Anode ‘B’. A salient feature of our work is that the data were collected on 50 μm thick Anodes screen-printed on 110 μm thick YSZ electrolytes and the experiments were carried out in a fuel cell configuration. Orders in methane and steam were both higher on the modified Ni-YSZ Anode. Activation energy was also higher on this Anode suggesting different nature of sites in the two Anodes. In the present study we have attempted to generate kinetic data at steam/carbon ratios which are economically attractive for fuel cell operation.
Mahendra Rao Somalu - One of the best experts on this subject based on the ideXlab platform.
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A review on the selection of Anode materials for solid-oxide fuel cells
Renewable and Sustainable Energy Reviews, 2015Co-Authors: Shabana P.s. Shaikh, Andanastuti Muchtar, Mahendra Rao SomaluAbstract:Solid-oxide fuel cells (SOFCs) are the most widely used fuel cells because they exhibit flexibility, power generation efficiency, and low pollution formation. Research on SOFC Anodes is a major and challenging task in the field of SOFCs. This review highlights the Anode materials that may be used for SOFC applications. The use of cermet-based oxide materials as Anodes for SOFCs is also discussed in detail. A literature survey conducted over the last 10 years shows that increased power generation efficiency may be attributed to Anode materials used in such cells. Oxide-based Anode materials with perovskite and several oxides with cubic fluorite structures are further described. Based on the review conducted, we find that cubic fluorite-structured compounds are the most promising Anode materials reported thus far. Analyses of the structure and electrical performance of Anode materials show as well that copper-gadolinium-doped cerium oxide (Cu-GDC) cubic fluorite-structured Anodes exhibit higher electronic conductivity potential than yttria-stabilized zirconia-based Anode materials.
Mikhail L Zheludkevich - One of the best experts on this subject based on the ideXlab platform.
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ca in micro alloying as a novel strategy to simultaneously enhance power and energy density of primary mg air batteries from Anode aspect
Journal of Power Sources, 2020Co-Authors: Min Deng, Linqian Wang, Daniel Hoche, Sviatlana V Lamaka, Pingli Jiang, Darya Snihirova, Nico Scharnagl, Mikhail L ZheludkevichAbstract:Abstract Herein we report micro-alloying with the combination of Ca/In as a novel strategy to improve the Anode performance for Mg-air batteries. Two micro-alloyed Mg–Ca–In Anodes, i.e. Mg−0.1%Ca−0.2%In and Mg−0.2%Ca−0.4%In (wt%), are fabricated and evaluated in both configurations: half-cell and Mg-air full cell. Re-deposition of metallic In on Anode surface during discharge is demonstrated. Anodic activation is then promoted by galvanic coupling between Mg and the re-deposited In, and film breakdown induced by In re-precipitation at the substrate/oxide film interface. Thus, the voltage and power density of Mg-air system are enhanced via adopting Mg–Ca–In Anodes. Besides, wasteful-discharge of the Ca/In micro-alloyed Anodes, which is related to the negative difference effect (NDE), is significantly suppressed. Anodic efficiency is consequently improved, reaching 80.2% at 5 mA cm−2 initial current density, and so is the service life of the Mg-air battery. Due to the enhanced voltage and anodic efficiency, Mg–Ca–In Anodes enable Mg-air battery to exhibit outstanding energy density, e.g. 2259 Wh kg−1 at 5 mA cm−2. Mg−0.1%Ca−0.2%In Anode possesses superior performance in terms of low wasteful-discharge, enhanced discharge activity and high anodic efficiency. Therefore, we recommend micro-alloyed Mg–Ca–In, like Mg−0.1%Ca−0.2%In, as excellent candidates for Anode materials of primary aqueous Mg-air batteries.