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Full-Text Articles in Engineering

Hydrophobic Hydrogel Caged H3Po4 As A New Class Of High-Temperature Proton Exchange Membranes With Enhanced Acid Retention, Qunwei Tang, Guoging Qian, Kevin Huang Feb 2015

Hydrophobic Hydrogel Caged H3Po4 As A New Class Of High-Temperature Proton Exchange Membranes With Enhanced Acid Retention, Qunwei Tang, Guoging Qian, Kevin Huang

Kevin Huang

We herein report a new class of high-temperature proton exchange membranes comprised of poly(acrylic acid-graft-hexadecyltrimethylammonium bromide) (PAA-g-CTAB) or poly(acrylic acid)-graft-poly(ethylene glycol) (PAA-g-PEG) hydrophobic hydrogel caged H3PO4. The membranes exhibit reasonable proton conductivity, enhanced H3PO4 retention ability and low solubility in water, making them promising as potential high performance and robust electrolytes for high-temperature proton exchange membrane fuel cells. Although the proton conductivity is still lower than that of H3PO4 doped PBI membranes, the new concept provides a different approach to proton exchange membranes for acid retention.


Cathode Polarizations Of A Cathode-Supported Solid Oxide Fuel Cell, Kevin Huang, Alessandro Zampieri, Martin Ise Feb 2015

Cathode Polarizations Of A Cathode-Supported Solid Oxide Fuel Cell, Kevin Huang, Alessandro Zampieri, Martin Ise

Kevin Huang

The concentration, activation, and total polarizations of the cathode in a cathode-supported solid oxide fuel cell (SOFC) were theoretically and experimentally investigated. In the theoretical analysis, the exchange current density of the charge transfer was considered to be dependent on the PO2 determined by the preceding O2 diffusion, resulting in an interrelationship between activation and concentration polarizations. The established nonlinear polarization equations were then applied to solve the key parameters with area specific resistances and overpotentials of the polarizations experimentally measured by electrochemical impedance spectroscopy on an operating cathode-supported SOFC. To ensure the consistency and meaningfulness of the solutions, the …


One-Step Infiltration Of Mixed Conducting Electrocatalysts For Reducing Cathode Polarization Of A Commercial Cathode-Supported Sofc, Nansheng Xu, Xue Li, Xuan Zhao, Hailei Zhao, Kevin Huang Feb 2015

One-Step Infiltration Of Mixed Conducting Electrocatalysts For Reducing Cathode Polarization Of A Commercial Cathode-Supported Sofc, Nansheng Xu, Xue Li, Xuan Zhao, Hailei Zhao, Kevin Huang

Kevin Huang

Infiltrating fine-grained electrocatalyst particles of either ion conducting or mixed electron and ion conducting (MEIC) material into a ceramic porous electrode scaffold has proven a very effective way to improve electrode performance for low to intermediate temperature solid oxide fuel cells (SOFCs). We report here one-step infiltration of MEIC fine particles, La0.6Sr0.4CoO3-δ (LSCo) and SrCo0.8Fe0.2O3-δ (SCF), into a commercial cathode substrate. A comparative study shows that the cathode polarization can be considerably reduced by a factor of 17 to 28 and 28 to 49 from 1000 to 700 ³C by the infiltrated LSCF and SCF electrocatalysts, respectively, demonstrating an effective …


Enhanced Reversibility And Durability Of A Solid Oxide Fe–Air Redox Battery By Carbothermic Reaction Derived Energy Storage Materials, Xuan Zhao, Xue Li, Yunhui Gong, Kevin Huang Feb 2015

Enhanced Reversibility And Durability Of A Solid Oxide Fe–Air Redox Battery By Carbothermic Reaction Derived Energy Storage Materials, Xuan Zhao, Xue Li, Yunhui Gong, Kevin Huang

Kevin Huang

The recently developed solid oxide metal–air redox battery is a new technology capable of high-rate chemistry. Here we report that the performance, reversibility and stability of a solid oxide iron–air redox battery can be significantly improved by nanostructuring energy storage materials from a carbothermic reaction.


Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang Feb 2015

Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Kevin Huang

“Metal-air” batteries have garnered much attention in recent years due to their high intrinsic specific energy and use of inexhaustible and storage-free oxygen source -air- for the “metal-oxygen” reaction. In this study, we report theperformance of a new type of all solid-state “iron-air” battery operated at 550°C. The results show that CeO2 nanoparticles incorporated into the Fe-Fe3O4 redox-couple can improve the specific energy (Wh/kg) and round trip efficiency by 15% and 29%, respectively, over the baseline Fe-Fe3O4 battery. Use of supported Fe-Fe3O4 nanoparticles as the redox couple can increase the specific energy and round-trip efficiency by 13% and 48% over …


Performance Of A Commercial Cathode-Supported Solid Oxide Fuel Cells Prepared By Single-Step Infiltration Of An Ion-Conducting Electrocatalyst, Xue Li, Nansheng Xu, Xuan Zhao, Kevin Huang Feb 2015

Performance Of A Commercial Cathode-Supported Solid Oxide Fuel Cells Prepared By Single-Step Infiltration Of An Ion-Conducting Electrocatalyst, Xue Li, Nansheng Xu, Xuan Zhao, Kevin Huang

Kevin Huang

No abstract provided.


Gas-Diffusion Process In A Tubular Cathode Substrate Of An Sofc, Part I: Theoretical Analysis Of Gas-Diffusion Process Under Cylindrical Coordinate System, Kevin Huang Feb 2015

Gas-Diffusion Process In A Tubular Cathode Substrate Of An Sofc, Part I: Theoretical Analysis Of Gas-Diffusion Process Under Cylindrical Coordinate System, Kevin Huang

Kevin Huang

In this the first part of a two-part paper, the gas-diffusion process through a thick and porous tubular cathode substrate of a solid oxide fuel cell-(SOFC) was theoretically analyzed using classic Fick’s diffusion equation under the cylindrical coordinate system. The effects of current density, temperature, oxygen diffusivity or porosity, wall thickness, and bulk pO2 on the concentration (or pore in this paper) polarization were calculated and are presented graphically. The results clearly show a greater impact on pore polarization by current density, oxygen diffusivity, wall thickness, and bulk pO2, but not by temperature. In addition, …


Phosphoric Acid-Imbibed Three-Dimensional Polyacrylamide/Poly(Vinyl Alcohol) Hyrdogel As A New Class Of High-Temperature Proton Exchange Membrane, Qunwei Tang, Kevin Huang, Guoging Qian, Brian Benicewicz Feb 2015

Phosphoric Acid-Imbibed Three-Dimensional Polyacrylamide/Poly(Vinyl Alcohol) Hyrdogel As A New Class Of High-Temperature Proton Exchange Membrane, Qunwei Tang, Kevin Huang, Guoging Qian, Brian Benicewicz

Kevin Huang

No abstract provided.


Increasing Power Density Of Lsgm-Based Solid Oxide Fuel Cells Using New Anode Materials, Kevin Huang, Jen-Hau Wan, John Goodenough Feb 2015

Increasing Power Density Of Lsgm-Based Solid Oxide Fuel Cells Using New Anode Materials, Kevin Huang, Jen-Hau Wan, John Goodenough

Kevin Huang

Chemical reactions between the superior perovskite oxide-ion conductor Sr- and Mg-doped LaGaO3 (LSGM), CeO2, and NiO have been studied by powder X-ray diffraction. The results showed that an extensive reactivity occurs as a result of La migration driven by a gradient of La chemical activity. La migration across the LSGM/electrode interfaces in a fuel cell leads to the formation of resistive phases at the interface, either LaSrGa3O7 or LaSrGaO4. Use of 40 mol % La2O3 -doped CeO2 as an interlayer between anode and electrolyte as well as in the NiO-containing anode prevents all reactions found. Consequently, the air-H2 cell maximum …


Characterization Of Iron-Based Alloy Interconnects For Reduced Temperature Solid Oxide Fuel Cells, Kevin Huang, Peggy Hou, John Goodenough Feb 2015

Characterization Of Iron-Based Alloy Interconnects For Reduced Temperature Solid Oxide Fuel Cells, Kevin Huang, Peggy Hou, John Goodenough

Kevin Huang

No abstract provided.


Cathode-Supported Tubular Solid Oxide Fuel Cell Technology: A Critical Review, Kevin Huang Feb 2015

Cathode-Supported Tubular Solid Oxide Fuel Cell Technology: A Critical Review, Kevin Huang

Kevin Huang

No abstract provided.


Superior Perovskite Oxide-Ion Conductor Sr- And Mg- Doped Lagao3: Part Ii Ac Impedance Spectroscopy, Kevin Huang, Robin Tichy, John Goodenough Feb 2015

Superior Perovskite Oxide-Ion Conductor Sr- And Mg- Doped Lagao3: Part Ii Ac Impedance Spectroscopy, Kevin Huang, Robin Tichy, John Goodenough

Kevin Huang

No abstract provided.


Superior Perovskite Oxide-Ion Conductor; Strontium- And Magnesium-Doped Lagao3: Iii, Performance Tests Of Single Ceramic Fuel Cells, Kevin Huang, Robin Tichy, John Goodenough, Christopher Milliken Feb 2015

Superior Perovskite Oxide-Ion Conductor; Strontium- And Magnesium-Doped Lagao3: Iii, Performance Tests Of Single Ceramic Fuel Cells, Kevin Huang, Robin Tichy, John Goodenough, Christopher Milliken

Kevin Huang

No abstract provided.


Electrical Conductivity And Stability Of A-Site Deficient (La, Sc) Co-Doped Srtio3 Mixed Ionic-Electronic Conductor, Xue Li, Hailei Zhao, Dawei Luo, Kevin Huang Feb 2015

Electrical Conductivity And Stability Of A-Site Deficient (La, Sc) Co-Doped Srtio3 Mixed Ionic-Electronic Conductor, Xue Li, Hailei Zhao, Dawei Luo, Kevin Huang

Kevin Huang

No abstract provided.


Molten Carbonates As An Effective Oxygen Reduction Catalyst For 550–650°C Solid Oxide Fuel Cells, Yunhui Gong, Xue Li, Lingling Zhang, Whitney Tharp, Changyong Qin, Kevin Huang Feb 2015

Molten Carbonates As An Effective Oxygen Reduction Catalyst For 550–650°C Solid Oxide Fuel Cells, Yunhui Gong, Xue Li, Lingling Zhang, Whitney Tharp, Changyong Qin, Kevin Huang

Kevin Huang

We report the first study that investigates the use of molten carbonates as an effective catalyst to promote electrochemical oxygen reduction reaction (ORR) at the cathode of intermediate temperature solid oxide fuel cells (IT-SOFCs). A series of binary Li-K carbonate compositions were incorporated into the porous backbones of a commercial cathode assembled in symmetrical impedance cells for electrochemical characterization. Within the temperature range of 550–650◦C, we observed that the polarization and ohmic area-specific resistances of the original sample can be significantly reduced by the introduction of molten carbonates. A new ORR charge-transfer model involving two intermediate species CO5 2− and …


Rapid Determination Of Electronic Conductivity In Mgo-Partially Stabilized Zro2 Electrolytes Using Emf Method, Kevin Huang, Yuhua Xia, Qingguo Liu Feb 2015

Rapid Determination Of Electronic Conductivity In Mgo-Partially Stabilized Zro2 Electrolytes Using Emf Method, Kevin Huang, Yuhua Xia, Qingguo Liu

Kevin Huang

No abstract provided.


Geometry-Dependent Oxygen Diffusion Flux And Limiting Current Density Of The Cathode In A Cathode-Supported Solid Oxide Fuel Cell, Kevin Huang, James Shull Feb 2015

Geometry-Dependent Oxygen Diffusion Flux And Limiting Current Density Of The Cathode In A Cathode-Supported Solid Oxide Fuel Cell, Kevin Huang, James Shull

Kevin Huang

An analysis is performed on the diffusion of oxygen through tubular porous cathode substrates having several different geometries. It is shown that the flux of oxygen as it diffuses through these different substrate geometries can be explicitly expressed by a general analytical form with a unique geometric factor for each type of substrate geometry. Experimental measurements of the geometry-independent term, oxygen diffusivity, were conducted for two representative geometries: cylindrical and triangular tubes. These measurements show good agreement between samples with similar porosities and thus favorably support the oxygen flux equations presented. Formulations for the limiting current density were also derived …


Characterization Of Ba1-X-YCaXSrYTio3 Perovskites As Pb-Free Dielectric Materials, Lingling Zhang, Siwei Wang, Xusheng Wang, Kevin Huang Feb 2015

Characterization Of Ba1-X-YCaXSrYTio3 Perovskites As Pb-Free Dielectric Materials, Lingling Zhang, Siwei Wang, Xusheng Wang, Kevin Huang

Kevin Huang

Use of lead-containing piezoelectric components in electrical and electronic devices has been banned on the EU market since July 1st, 2006. Development of lead-free high performance piezoelectric materials to meet the strong market demand is therefore imperative. In this paper, we report a systematic study on the structural, dielectric and ferroelectric properties of one class of lead-free piezoelectric materials, Ba1-x-yCaxSryTiO3 (x = 0-0.4, and y = 0-0.2) ceramics, using techniques such as XRD, SEM, impedance analyzer, and ferroelectric analyzer. It is found that with increasing Sr concentration in Ba1-ySryTiO3 and Ba0.8-ySryCa0.2TiO3, the crystal structure transforms from tetragonal to cubic along …


Synthesis And Characterizations Of A-Site Deficient Perovskite Sr0.9Ti0.8−XGaXNb0.2O3, Guoliang Xiao, Xihui Dong, Kevin Huang, Fanglin Chen Feb 2015

Synthesis And Characterizations Of A-Site Deficient Perovskite Sr0.9Ti0.8−XGaXNb0.2O3, Guoliang Xiao, Xihui Dong, Kevin Huang, Fanglin Chen

Kevin Huang

No abstract provided.


Flux Of Silver-Carbonate Membranes For Post-Combustion Co2 Capture: The Effects Of Membrane Thickness, Gas Concentration And Time, Lingling Zhang, Yunhui Gong, Kyle Brinkman, Tao Wei, Siwei Wang, Kevin Huang Feb 2015

Flux Of Silver-Carbonate Membranes For Post-Combustion Co2 Capture: The Effects Of Membrane Thickness, Gas Concentration And Time, Lingling Zhang, Yunhui Gong, Kyle Brinkman, Tao Wei, Siwei Wang, Kevin Huang

Kevin Huang

No abstract provided.


A High Energy Density All Solid-State Tungsten-Air Battery, Xuan Zhao, Xue Li, Yunhui Gong, Nansheng Xu, Kevin Gregory Romito, Kevin Huang Feb 2015

A High Energy Density All Solid-State Tungsten-Air Battery, Xuan Zhao, Xue Li, Yunhui Gong, Nansheng Xu, Kevin Gregory Romito, Kevin Huang

Kevin Huang

An all solid-state tungsten–air battery using solid oxide–ion electrolyte is demonstrated as a new chemistry for advanced energy storage. The unique design of separated energy storage from the electrodes allows for free volume expansion–contraction during electrical cycles and new metal–air chemistry to be explored conveniently.


Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar Patel, Xinhua Liang, Xuan Zhao, John Goodenough, Kevin Huang Feb 2015

Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar Patel, Xinhua Liang, Xuan Zhao, John Goodenough, Kevin Huang

Kevin Huang

No abstract provided.


Surface Modified Silver-Carbonate Mixed Conducting Membranes For High Flux Co2 Separation With Enhanced Stability, Lingling Zhang, Yunhui Gong, Jacob Yaggie, Siwei Wang, Kevin Romito, Kevin Huang Feb 2015

Surface Modified Silver-Carbonate Mixed Conducting Membranes For High Flux Co2 Separation With Enhanced Stability, Lingling Zhang, Yunhui Gong, Jacob Yaggie, Siwei Wang, Kevin Romito, Kevin Huang

Kevin Huang

No abstract provided.


Solid Oxide Iron-Air Rechargeable Battery - A New Energy Storage Mechanism, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang Feb 2015

Solid Oxide Iron-Air Rechargeable Battery - A New Energy Storage Mechanism, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang

Kevin Huang

No abstract provided.


First Spectroscopic Identification Of Pyrocarbonate For High Co2 Flux Membranes Containing Highly Interconnected Three Dimensional Ionic Channels, Lingling Zhang, Xinyu Huang, Changyong Qin, Kyle Brinkman, Yunhui Gong, Siwei Wang, Kevin Huang Feb 2015

First Spectroscopic Identification Of Pyrocarbonate For High Co2 Flux Membranes Containing Highly Interconnected Three Dimensional Ionic Channels, Lingling Zhang, Xinyu Huang, Changyong Qin, Kyle Brinkman, Yunhui Gong, Siwei Wang, Kevin Huang

Kevin Huang

Identification of the existence of pyrocarbonate ion C2O52− in molten carbonates exposed to a CO2 atmosphere provides key support for a newly established bi-ionic transport model that explains the mechanisms of high CO2 permeation flux observed in mixed oxide-ion andcarbonate-ion conducting (MOCC) membranes containing highly interconnected three dimensional ionic channels. Here we report the first Raman spectroscopic evidence of C2O52− as an active species involved in the CO2-transport process of MOCC membranes exposed to a CO2atmosphere. The two new broad peaks centered at 1317 cm−1 …


Enhanced Methanol Oxidation And Co Tolerance Using Ceo2-Added Eggshell Membrane-Templated Pd Network Electrocatalyst, Qunwei Tang, Zhengping Mao, Shuguo Ma, Kevin Huang Feb 2015

Enhanced Methanol Oxidation And Co Tolerance Using Ceo2-Added Eggshell Membrane-Templated Pd Network Electrocatalyst, Qunwei Tang, Zhengping Mao, Shuguo Ma, Kevin Huang

Kevin Huang

Macroporous Pd and CeO2-added Pd network catalysts have been synthesized using eggshell membrane (ESM) as a template for enhanced methanol oxidation and CO tolerance. The microstructural characterization revealed a hierarchically ordered macroporous network of Pd reproducing the fibrous structure of ESM for a Pd-only catalyst, and a flower-like CeO2-decorated Pd morphological architecture for the CeO2-added Pd catalyst synthesized by a precipitation method. XRD patterns indicated Pd and CeO2 phases with good crystallinity. The cyclic voltammetry studies showed an enhanced electrocatalytic activity for methanol oxidation in acidic aqueous medium. Because of the preferential formation of Ce–CO bonds over Pd–CO bonds, the …


Energy Storage Characteristics Of A New Rechargeable Solid Oxide Iron-Air Battery, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang Feb 2015

Energy Storage Characteristics Of A New Rechargeable Solid Oxide Iron-Air Battery, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang

Kevin Huang

Cost effective and large scale energy storage is critical to renewable energy integration and smart-grid energy infrastructure. Rechargeable batteries have great potential to become a class of cost effective technology suited for large scale energy storage. In this paper, we report the energy storage characteristics of a newly developed rechargeable solid oxide iron–air battery. Investigations of the battery’s performance under various current densities and cycle durations show that iron utilization plays a determining role in storage capacity and round-trip efficiency. Further studies of the battery's cycle life reveal a unique charge-cycle originated degradation mechanism that can be interpreted by a …


Long Term Stability Study Of A Solid Oxide Metal-Air Battery, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang Feb 2015

Long Term Stability Study Of A Solid Oxide Metal-Air Battery, Xuan Zhao, Nansheng Xu, Xue Li, Yunhui Gong, Kevin Huang

Kevin Huang

No abstract provided.


Low Temperature Densification And Electrical Property Of A Carbonate-Added Proton Conducting Ceramic, Xue Li, Nansheng Xu, Lingling Zhang, Kevin Huang Feb 2015

Low Temperature Densification And Electrical Property Of A Carbonate-Added Proton Conducting Ceramic, Xue Li, Nansheng Xu, Lingling Zhang, Kevin Huang

Kevin Huang

Proton conducting yttrium-doped barium zirconate (BZY) is one of the most studied materials for SOFC applications due to its high bulk proton conductivity, good chemical stability under CO2 and mechanical robustness. However, it requires a very high temperature (1700-2100°C) and long sintering time (>24 h), even with nano-sized powers, to sinter into a dense ceramic. In this paper, we demonstrate a unique approach to make a dense BZY at much lower temperatures. The method involves prefabrication of a porous BZY matrix by solid-state reaction from micro-sized powders of BaCO3, ZrO2 and Y2O3 and densification by impregnating the porous BZY …


Oxide-Ion Conducting Ceramics For Solid Oxide Fuel Cells, Kevin Huang, Jen-Hau Wan, John Goodenough Feb 2015

Oxide-Ion Conducting Ceramics For Solid Oxide Fuel Cells, Kevin Huang, Jen-Hau Wan, John Goodenough

Kevin Huang

No abstract provided.