412 results found
Kishimoto M, Lomberg M, Ruiz-Trejo E, et al., 2014, Towards the microstructural optimisation of solid oxide fuel cell electrodes
One-dimensional numerical simulation and microstructural analysis of solid oxide fuel cell (SOFC) electrodes are carried out to investigate the effect of the characteristic length scale of the porous electrodes on the performance. The sensitivity of the current density is analysed over a wide range of triple-phase boundary (TPB) density and mean-pore size, which affect the electrochemical reaction and gas transport. Comparison between conventional electrodes and nano-particle infiltrated electrodes reveals that reducing characteristic length scale in the conventional electrodes helps improve the electrode performance by reducing the reaction resistance; however, introducing nano particles into the electrodes is expected to be more effective as it has a potential to increase the TPB density whilst keeping better gaseous transport through the electrodes. The three-dimensional microstructures of both types of electrodes are obtained with focused ion beam scanning electron microscopy and provide useful microstructural information that supports the numerical analysis.
Guerra C, Lanzini A, Leone P, et al., 2014, Optimization of dry reforming of methane over Ni/YSZ anodes for solid oxide fuel cells, JOURNAL OF POWER SOURCES, Vol: 245, Pages: 154-163, ISSN: 0378-7753
kucernak, brandon, yufit, 2013, regenerative fuel cells
The present invention provides a regenerative fuel cell comprising an anionic membrane capable of selectively passing anions, wherein the pH of the anolyte and/or catholyte is at least 10. The present invention also relates to a method of operating a regenerative fuel cell comprising an anionic membrane capable of selectively passing anions, wherein the pH of the anolyte and/or catholyte is at least 10.
Wu B, Yufit V, Marinescu M, et al., 2013, Coupled thermal–electrochemical modelling of uneven heat generation in lithium-ion battery packs, Journal of Power Sources, Vol: 243, Pages: 544-554, ISSN: 0378-7753
Abstract In battery packs with cells in parallel, the inter-cell connection resistances can cause unequal loads due to non-uniform interconnect overpotentials and consequentially lead to non-uniform heating. This article explores how load imbalances are generated in automotive applications, by describing a battery pack with finite interconnect resistances. Each cell inside the pack is represented by a pseudo 2D electrochemical model coupled with a lumped thermal model. Increasing the number of cells in parallel results in a linear increase in load non-uniformity, whilst increasing the ratio of interconnect to battery impedance results in a logarithmic increase in load non-uniformity, with cells closest to the load points experiencing the largest currents. Therefore, interconnect resistances of the order of mΩ can have a significant detrimental impact. Under steady state discharge the cell impedance changes until the loads balance. This process, however, can take hundreds of seconds and therefore may never happen under dynamic load cycles. Cycling within a narrow state-of-charge range and pulse loading are shown to be the most detrimental situations. Upon load removal, re-balancing can occur causing further heating. Simulation of a 12P7S pack under a real world load cycle shows that these effects could cause localised thermal runaway.
Chakrabarti MH, Brandon NP, Mjalli FS, et al., 2013, Cyclic Voltammetry of Metallic Acetylacetonate Salts in Quaternary Ammonium and Phosphonium Based Deep Eutectic Solvents, JOURNAL OF SOLUTION CHEMISTRY, Vol: 42, Pages: 2329-2341, ISSN: 0095-9782
Lorente E, Berrueco C, Millan M, et al., 2013, Effect of tar fractions from coal gasification on nickel-yttria stabilized zirconia and nickel-gadolinium doped ceria solid oxide fuel cell anode materials, JOURNAL OF POWER SOURCES, Vol: 242, Pages: 824-831, ISSN: 0378-7753
Cooper SJ, Kishimoto M, Tariq F, et al., 2013, Microstructural Analysis of an LSCF Cathode Using In Situ Tomography and Simulation, ECS Transactions, Vol: 57, Pages: 2671-2678, ISSN: 1938-6737
Electrode tortuosity factor is a key input parameter in many fuel cell simulations. Three-dimensional microstructural data obtained from in-situ synchrotron X-ray nano-computed tomography is used as the basis for comparing five approaches to quantify the tortuosity factor. Three of these techniques are based on diffusivity simulations and showed strong correlation, but had consistently different absolute values. A random walk method showed a good degree of correlation to the diffusive approaches, but had the largest values overall. Lastly, a calculation that used a mean pore centroid approach showed little correlation to any of the other three methods, but compared well with the conventional Bruggeman correlation. Due to the diffusive nature of the ionic transport in electrodes, the authors would recommend calculating tortuosity factors using a diffusive approach based on the voxels rather than a remeshed volume.
Tariq F, Kishimoto M, Cooper SJ, et al., 2013, Advanced 3D Imaging and Analysis of SOFC Electrodes, ECS Transactions, Vol: 57, Pages: 2553-2562, ISSN: 1938-6737
Solid Oxide Fuel Cells (SOFC) are electrochemical devices where performance is dependent on reactions inside porous electrode microstructures; their complexity is inadequately described using 2D imaging. Here we use X-ray Nano-CT tomographic techniques to probe 3D electrode structures (anodes and cathodes) at micro-nanometer length scales produced using a focused ion beam. Subsequently, micro/nano structural changes in SOFC electrodes are followed and quantified to facilitate understanding changes that occur in shape, structures and morphology at high sub-100nm resolution. Time-resolved (4D) imaging revealed Ni-YSZ oxidation markedly increased above 500 ºC and LSCF densification at 700 ºC may close pores. Utilising 3D electrode data as geometric inputs for numerical models, revealed that increased strains were located at Ni-YSZ interfaces and at microstructure constrictions for both anodes and cathodes when heated. The results show nano/micro structural changes can affect the performance of SOFC electrodes. This combined experimental and modelling approach can help in establishing structure/performance relationships providing key insights important for transport, electrochemistry and strains in both SOFC anodes and cathodes and understanding sources of performance degradation.
Brandon NP, Corcoran D, Cummins D, et al., 2013, Development of metal supported solid oxide fuel cells for operation at 500-600 °c, Pages: 2900-2903, ISSN: 1059-9495
A novel metal-supported solid oxide fuel cell has been developed that is capable of operating at temperatures of 500-600 °C. The rationale behind the materials used to construct this fuel cell type is given, and results are presented from cell testing on hydrogen and reformed natural gas, including durability trials of some 2500 h duration. This new fuel cell variant is shown to be tolerant of carbon monoxide, durable, robust to thermal and redox cycling, and capable of delivering technologically relevant power densities. © 2013 ASM International.
Chakrabarti MH, Low CTJ, Brandon NP, et al., 2013, Progress in the electrochemical modification of graphene-based materials and their applications, Electrochimica Acta, Vol: 107, Pages: 425-440, ISSN: 0013-4686
Graphene is a 2D allotrope of carbon with exciting properties such as extremely high electronic conductivity and superior mechanical strength. It has considerable potential for applications in fields such as bio-sensors, electrochemical energy storage and electronics. In most cases, graphene has been functionalized and modified with other materials to prepare composites. This work reviews the electrochemical modification of graphene. Commencing with a brief history, a summary of several different means of modifying graphene to effect diverse applications is provided. This is followed by a discussion on different composite materials that have been prepared with reduced graphene oxide prior to moving onto a detailed consideration of six different methods of electrochemically modifying graphene to prepare composite materials. These methods involve cathodic reduction of graphene oxide, electrophoretic deposition, electro-deposition techniques, electrospinning, electrochemical doping and electrochemical polymerization. Finally a consideration on the applications of electrochemically modified graphene composite materials in various fields is presented prior to discussing some prospects in enhancing the electrochemical process to realize excellent and economic composite materials in bulk.
Rhazaoui K, Cai Q, Adjiman CS, et al., 2013, Towards the 3D modeling of the effective conductivity of solid oxide fuel cell electrodes: I. Model development, CHEMICAL ENGINEERING SCIENCE, Vol: 99, Pages: 161-170, ISSN: 0009-2509
Millichamp J, Mason TJ, Brandon NP, et al., 2013, A study of carbon deposition on solid oxide fuel cell anodes using electrochemical impedance spectroscopy in combination with a high temperature crystal microbalance, JOURNAL OF POWER SOURCES, Vol: 235, Pages: 14-19, ISSN: 0378-7753
Maher RC, Duboviks V, Offer GJ, et al., 2013, Raman Spectroscopy of Solid Oxide Fuel Cells: Technique Overview and Application to Carbon Deposition Analysis, FUEL CELLS, Vol: 13, Pages: 455-469, ISSN: 1615-6846
Somalu MR, Yufit V, Brandon NP, 2013, The effect of solids loading on the screen-printing and properties of nickel/scandia-stabilized-zirconia anodes for solid oxide fuel cells, INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, Vol: 38, Pages: 9500-9510, ISSN: 0360-3199
Chakrabarti MH, Brandon NP, Hashim MA, et al., 2013, Cyclic Voltammetry of Iron (III) Acetylacetonate in Quaternary Ammonium and Phosphonium Based Deep Eutectic Solvents, INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE, Vol: 8, Pages: 9652-9676, ISSN: 1452-3981
Somalu MR, Yufit V, Shapiro IP, et al., 2013, The impact of ink rheology on the properties of screen-printed solid oxide fuel cell anodes, INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, Vol: 38, Pages: 6789-6801, ISSN: 0360-3199
Cooper SJ, Eastwood DS, Gelb J, et al., 2013, Image Based Modelling of of Microstructural Heterogeneity in LiFePO4 Electrodes for Li-ion Batteries, Journal of Power Sources, Vol: 247, Pages: 1033-1039, ISSN: 0378-7753
Battery and fuel cell simulations commonly assume that electrodes are macro-homogeneous and isotropic. These simulations have been used to successfully model performance, but give little insight into predicting failure. In Li-ion battery electrodes, it is understood that local tortuosity impacts charging rates, which may cause increased degradation. This report describes a novel approach to quantifying tortuosity based on a heat transfer analogy applied to X-ray microscopy data of a commercially available LiFePO4 electrode. This combination of X-ray imaging and image-based simulation reveals the microscopic performance of the electrode; notably, the tortuosity was observed to vary significantly depending on the direction considered, which suggests that tortuosity might best be quantified using vectors rather than scalars.
Mook WT, Aroua MK, Chakrabarti MH, et al., 2013, The application of nano-crystalline PbO2 as an anode for the simultaneous bio-electrochemical denitrification and organic matter removal in an up-flow undivided reactor, ELECTROCHIMICA ACTA, Vol: 94, Pages: 327-335, ISSN: 0013-4686
Lanzini A, Leone P, Guerra C, et al., 2013, Durability of anode supported Solid Oxides Fuel Cells (SOFC) under direct dry-reforming of methane, CHEMICAL ENGINEERING JOURNAL, Vol: 220, Pages: 254-263, ISSN: 1385-8947
Ruiz-Trejo E, Boldrin P, Lubin A, et al., 2013, Silver-ceria composites for oxygen separation from air, 224th Electrochemical society meeting
Lomberg M, Ruiz-Trejo E, Offer G, et al., 2013, Characterization of a Novel Ni-impregnated GDC Electrode for Solid Oxide Fuel Cell and Electrolysis Cell Applications, SOLID OXIDE FUEL CELLS 13 (SOFC-XIII), Vol: 57, Pages: 1349-1357, ISSN: 1938-5862
Duboviks V, Maher RC, Offer G, et al., 2013, In-Operando Raman Spectroscopy Study of Passivation Effects on Ni-CGO Electrodes in CO2 Electrolysis Conditions, 13th International Symposium on Solid Oxide Fuel Cells (SOFC-XIII), Publisher: ELECTROCHEMICAL SOC INC, Pages: 3111-3117, ISSN: 1938-5862
Maher RC, Duboviks V, Offer G, et al., 2013, In-operando Raman Characterization of Carbon Deposition on SOFC Anodes, 13th International Symposium on Solid Oxide Fuel Cells (SOFC-XIII), Publisher: ELECTROCHEMICAL SOC INC, Pages: 1619-1626, ISSN: 1938-5862
Mazur C, Contestabile M, Offer GJ, et al., 2013, Understanding the automotive industry: German OEM behaviour during the last 20 years and its implications, World Electric Vehicle Journal, Vol: 6, Pages: 1054-1067, ISSN: 2032-6653
© 2013 WEVA Page. This work presents a study of how the automotive industry has responded in the last 20 years to pressures driven by economic and environmental issues, and by the transition towards electric mobility. Timelines for the major German automotive OEMs are presented to understand the industry's behaviour in the past in order to design suitable policies that are appropriate to reach future goals around the electrification of road transport. Based upon a comparison of the pressures arising in the automotive sector and the companies' behaviour with regard to technology choice and R&D, a set of hypotheses concerning this behaviour is then presented.
Somalu MR, Muchtar A, Baboli MG, et al., 2013, Understanding the Relationship between Ink Rheology and Film Properties for Screen-Printed Nickel/Scandia-Stabilized-Zirconia Anodes, 13th International Symposium on Solid Oxide Fuel Cells (SOFC-XIII), Publisher: ELECTROCHEMICAL SOC INC, Pages: 1321-1330, ISSN: 1938-5862
Guerra C, Lanzini A, Leone P, et al., 2013, Comparison of the catalytic properties of SOFC anode supports under dry reforming of methane, Pages: 73-74
Copyright © 2013 Delta Energy and Environment. The work investigates the catalytic properties of different SOFC anode substrates towards the chemical conversion of methane and carbon dioxide into H2 and CO-rich mixtures. The analysis is carried out by means of experiments in micro-reactor configuration. A mass spectrometer is provided to analyze the composition of the gas mixture leaving the reactor and thus allowing the evaluation of methane conversion rate. Furthermore, Temperature Programmed Oxidation (TPO) experiments are performed on the anode samples aiming at the analysis of material activity towards the cracking reaction of methane. Anode substrates based on different materials and microstructures are taken into account. The work features the effect of materials' composition and microstructure on the methane conversion rate and carbon cracking.
Clague R, Marquis AJ, Brandon NP, 2013, Time independent and time dependent probability of failure of solid oxide fuel cells by stress analysis and the Weibull method, JOURNAL OF POWER SOURCES, Vol: 221, Pages: 290-299, ISSN: 0378-7753
Parkes M, Refson K, d'Avezac M, et al., 2013, Determining Surface Chemistry and Vibrational Properties of SOFC Anode Materials Through ab initio Calculations, SOLID OXIDE FUEL CELLS 13 (SOFC-XIII), Vol: 57, Pages: 2419-2427, ISSN: 1938-5862
Maskell WC, Brett DJL, Brandon NP, 2013, Improvements to Zirconia Thick-Film Oxygen Sensors, 17th Conference on Sensors and Their Applications, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Yufit V, Hale B, Matian M, et al., 2013, Development of a Regenerative Hydrogen-Vanadium Fuel Cell for Energy Storage Applications, JOURNAL OF THE ELECTROCHEMICAL SOCIETY, Vol: 160, Pages: A856-A861, ISSN: 0013-4651
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.