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Editors’ Choice-Examining Performance And Durability Of Anion Exchange Membrane Fuel Cells With Novel Spirocyclic Anion Exchange Membranes, Ami C. Yang-Neyerlin, Samantha Medina, Kelly M. Meek, Derek J. Strasser, Cheng He, Daniel M. Knauss, Mustain E William, Svitlana Pylypenko, Bryan S. Pivovar
Editors’ Choice-Examining Performance And Durability Of Anion Exchange Membrane Fuel Cells With Novel Spirocyclic Anion Exchange Membranes, Ami C. Yang-Neyerlin, Samantha Medina, Kelly M. Meek, Derek J. Strasser, Cheng He, Daniel M. Knauss, Mustain E William, Svitlana Pylypenko, Bryan S. Pivovar
Faculty Publications
A series of spirocyclic copolymer membranes with varying ion exchange capacities (IECs) were investigated to probe the impact of polymer properties on in situ fuel cell performance and stability. In-situ electrochemical tests and post-mortem electron microscopy analysis of cross-sectioned membrane electrode assemblies (MEAs) have been combined with voltage loss breakdown analysis to evaluate the performance and degradation of different MEAs, and to probe the catalyst morphology and electrode structure at different stages of operation. Voltage loss breakdown results show that membrane degradation and kinetic losses played only a minor role in observed performance degradation and that performance losses were primarily …
High-Throughput 3d Reconstruction Of Stochastic Heterogeneous Microstructures In Energy Storage Materials, Yanxiang Zhang, Mufu Yan, Yanhong Wan, Zhenjun Jiao, Yu Chen, Fanglin Chen, Changrong Xia, Meng Ni
High-Throughput 3d Reconstruction Of Stochastic Heterogeneous Microstructures In Energy Storage Materials, Yanxiang Zhang, Mufu Yan, Yanhong Wan, Zhenjun Jiao, Yu Chen, Fanglin Chen, Changrong Xia, Meng Ni
Faculty Publications
Stochastic heterogeneous microstructures are widely applied in structural and functional materials, playing a crucial role in determining their performance. X-ray tomography and focused ion beam serial sectioning are frequently used methods to reconstruct three-dimensional (3D) microstructures, yet are demanding techniques and are resolution-limited. Here, a high-throughput multi-stage 3D reconstruction method via distance correlation functions is developed using a single representatively large-sized 2D micrograph for stochastic microstructures, and verified by X-ray micro-tomography datasets of isotropic and anisotropic solid oxide fuel cell electrodes. This method provides an economic, easy-to-use and high-throughput approach for reconstructing stochastic heterogeneous microstructures for energy conversion and storage …
Proton Transfer In Molten Lithium Carbonate: Mechanism And Kinetics By Density Functional Theory Calculations, Xueling Lei, Kevin Huang, Changyong Qin
Proton Transfer In Molten Lithium Carbonate: Mechanism And Kinetics By Density Functional Theory Calculations, Xueling Lei, Kevin Huang, Changyong Qin
Faculty Publications
Using static and dynamic density functional theory (DFT) methods with a cluster model of [(Li2CO3)8H]+, the mechanism and kinetics of proton transfer in lithium molten carbonate (MC) were investigated. The migration of proton prefers an inter-carbonate pathway with an energy barrier of 8.0 kcal/mol at the B3LYP/6-31 G(d,p) level, which is in good agreement with the value of 7.6 kcal/mol and 7.5 kcal/mol from experiment and FPMD simulation, respectively. At transition state (TS), a linkage of O–H–O involving O 2p and H 1 s orbitals is formed between two carbonate ions. The calculated trajectory of H indicates that proton has …
H3Po4-Imbibed Three-Dimensional Polyacrylamide/Polyacrylamide Hydrogel As A High-Temperature Proton Exchange Membrane With Excellent Acid Retention, Qunwei Tang, Guoging Qian, Kevin Huang
H3Po4-Imbibed Three-Dimensional Polyacrylamide/Polyacrylamide Hydrogel As A High-Temperature Proton Exchange Membrane With Excellent Acid Retention, Qunwei Tang, Guoging Qian, Kevin Huang
Faculty Publications
We herein report the use of polyacrylamide/polyacrylamide interpenetrating polymer network (PAM/PAM IPN) hydrogel as a matrix to imbibe proton conducting H3PO4, forming a robust proton exchange membrane (PEM) suitable for high-temperature PEM fuel cells by combining excellent acid retention, simple synthesis, and low cost. Its extraordinary ability to absorb large quantity of aqueous solution is fully utilized to achieve high H3PO4 loading, showing a proton conductivity of 0.0833 S cm−1 at 183 °C in dry air. The synthesized membrane also shows excellent acid retention even under mechanical load and high humidity. These profound …
Mechanics Of Composite Materials In Fuel Cell Systems, Kenneth Reifsnider, Xinyu Huang, G. Ju, Matthew Feshler, K. An
Mechanics Of Composite Materials In Fuel Cell Systems, Kenneth Reifsnider, Xinyu Huang, G. Ju, Matthew Feshler, K. An
Faculty Publications
The science and technology that are fundamental to the concept of composite materials are also the foundation for the construction and function of fuel cells and fuel cell systems. The present paper outlines this relationship in the context of the physics and chemistry that are enabled by the specific selection and arrangement of constituents of the “functional composite” fuel cell. General principles of operation are described, and fundamental issues are defined that must be addressed by the composites community if the fuel cell science and engineering is to advance. Examples of several types of functional composite fuel cells are presented, …
Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov
Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov
Faculty Publications
A method based on pulse electrodeposition technique was developed for preparation of membrane electrode assemblies (MEAs). In this approach, platinum is deposited directly on the surface of the carbon electrode. The method ensures most of the platinum to be in close contact with the membrane. Using this method it is possible to increase the Pt/C ratio up to 75 wt % near the surface of the electrode resulting in a 5 µm thick catalyst layer. The MEA prepared by pulse electrodeposition exhibits a current density of 0.33 A/cm2 at 0.8 V with platinum loading of 0.25 mg of Pt/cm …
Solvent Diffusion Model For Aging Of Lithium-Ion Battery Cells, Harry J. Ploehn, Premanand Ramadass, Ralph E. White
Solvent Diffusion Model For Aging Of Lithium-Ion Battery Cells, Harry J. Ploehn, Premanand Ramadass, Ralph E. White
Faculty Publications
This work presents a rigorous continuum mechanics model of solvent diffusion describing the growth of solid-electrolyte interfaces (SEIs) in Li-ion cells incorporating carbon anodes. The model assumes that a reactive solvent component diffuses through the SEI and undergoes two-electron reduction at the carbon-SEI interface. Solvent reduction produces an insoluble product, resulting in increasing SEI thickness. The model predicts that the SEI thickness increases linearly with the square root of time. Experimental data from the literature for capacity loss in two types of prototype Li-ion cells validates the solvent diffusion model. We use the model to estimate SEI thickness and extract …
Electrode Performance Test On Single Ceramic Fuel Cells Using As Electrolyte Sr‐ And Mg‐Doped Lagao3, Kevin Huang, Man Feng, John B. Goodenough, Christopher Milliken
Electrode Performance Test On Single Ceramic Fuel Cells Using As Electrolyte Sr‐ And Mg‐Doped Lagao3, Kevin Huang, Man Feng, John B. Goodenough, Christopher Milliken
Faculty Publications
The electrode performance of a single solid oxide fuel cell was evaluated using a 500 μm thick La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) as the electrolyte membrane. Comparison of La0.6Sr0.4CoO3-δ (LSCo) and La0.9Sr0.1MnO3 (LSM) as cathodes showed LSCo gave an exchange current density two orders of magnitude higher than that of LSM. Comparison of CeO2/Ni and LSGM/Ni as anodes showed a degradation of the latter with time, and studies of the anode‐electrolyte interface and the reactivity of NiO and LSGM suggest better anode …
Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White
Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White
Faculty Publications
No abstract provided.
A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White
A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White
Faculty Publications
A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict polarization behavior under various potential loads. The model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions, assuming a macrohomogeneous, three-phase porous electrode structure. The model calculates the spatial variation of the partial pressures of oxygen, hydrogen, and water vapor, dissolved oxygen and hydrogen concentrations, electrolyte concentration, and the solid- and solution-phase potential drops. By developing a complete model of the alkaline fuel cell, the interaction of the various transport and kinetic resistances can …