bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comprehensive Study of Thermal Stability on Microstructure and Residual Stress for ALD HfZrO2 Dielectric Films at 28nm HKMG CMOS Applications
Authors: Chiang Chen-Kuo
Published: February 2020

Abstract not Available.
Self-Cleaning and Electrical Characteristics of ZrO2 (HfO2)/GaAs MOS Capacitor Fabricated by Atomic Layer Deposition
Authors: Pradhan Aswini K , White Curtis
Published: February 2020

Abstract not Available.
TSV Filling By NiW Alloys Electroplating
Authors: Wang Hsin-Wei , Huang Hsin-Man , Dow Wei-Ping
Published: February 2020

Abstract not Available.
Modeling the Bottom-Up Filling of Through-Silicon Vias Through Suppressor Adsorption/Desorption Mechanism
Authors: Yang Liu , Radisic Aleksandar , Deconinck Johan , Vereecken Philippe M.
Published: February 2020

Abstract not Available.
Nitinol Surface Modification in Gentle Conditions By in
Situ Generated Diazonium Salt
Authors: Jacques Amory , Devillers Sébastien , Delhalle Joseph , Mekhalif Zineb
Published: February 2020

Abstract not Available.
Lithium-Doped Nickel Oxide and Nanostructured Tungsten Oxide Thin Films Made By USP, Toward Improved Electrochromic Performances
Authors: Denayer Jessica , Aubry Philippe , Colson Pierre , Henrist Catherine , Cloots Rudi
Published: February 2020

Abstract not Available.
A Multi-Frequency Megasonic System for Nano-Particle Removal
Authors: Kim Hyunse , Lee Yanglae , Lim Euisu
Published: February 2020

Abstract not Available.
Numerical Study of Single Bubble Dynamics in Megasonic Field for New Physical Cleaning Method
Authors: Ochiai Naoya , Ishimoto Jun
Published: February 2020

Abstract not Available.
Feol and Beol Cleaning Challenges for 2x and Sub-20nm Technology Nodes
Authors: Sehgal Akshey
Published: February 2020

Abstract not Available.
Selective Removal of Ashed Spin-On Glass
Authors: Wu Hsing-Chen , Tu Sheng-Hung
Published: February 2020

Abstract not Available.
Trace Metal Analysis of Cleanroom Dry Wipers By Inductively Coupled Plasma – Mass Spectrometry
Authors: Liu Shi , Liu Bin
Published: February 2020

Abstract not Available.
SiC Mos Interface States: Difference Between C Face and Si Face
Authors: Umeda Takahide , Okamoto Mitsuo , Kosugi Ryouji , Arai Ryo , Sato Yoshihiro , Harada Shinsuke , Makino Takahiro , Ohshima Takeshi
Published: February 2020

Abstract not Available.
Integration of High-k Dielectrics on Epitaxial (100), (110) and (111) Germanium for Multifunctional Devices
Authors: Hudait Mantu K , Zhu Yan , Maurya Deepam , Spriya Shashank
Published: February 2020

Abstract not Available.
Effect of Precursor Entrance Sequence During Atomic Layer Deposition On the Al2O3/Ge Interface By X-Ray Photoelectron Spectroscopy
Authors: Xiang Jinjuan , Wang Guilei , Li Tingting , Cui Hushan , Wang Xiaolei , Xu Gaobo , Li Junfeng , Wang Wenwu , Zhao Chao
Published: February 2020

Abstract not Available.
Pseudopotential-Based Study of Electron Transport in Low-Dimensionality Nanostructures
Authors: Fischetti Massimo V , Aboud Shela J , Ong Zhun-Yong , Kim Jiseok , Narayanan Sudarshan , Sachs Catherine E
Published: February 2020

Abstract not Available.
Photo-Bias Instability of Solution Processed Zinc Tin Oxide Thin Film Transistors With Varying Zn:Sn Composition Ratio
Authors: Kim Yoon Jang , Yang Bong Seob , Oh Seungha , Han Sang Jin , Kim Hyeong Joon
Published: February 2020

Abstract not Available.
Investigation On Oxygen Diffusion in a High-k Metal-Gate Stack for Advanced CMOS Technology By XPS
Authors: Kechichian Ardem , Barboux Philippe , Gros-Jean Mickael
Published: February 2020

Abstract not Available.
Growth, Properties, and Optoelectronic Applications of III-As and III-N Nanowires
Authors: Geelhaar Lutz
Published: February 2020

Abstract not Available.
Synthesis of MoS2 Atomic Layer using PECVD
Authors: Kim HyeongU , Ahn Chisung , Arabale Girish , Lee Changgu , Kim Taesung
Published: February 2020

Abstract not Available.
E-ALD of Pd On Au Single Crystals
Authors: Stickney John Lewellen , Sheridan Leah B , Kim Youn-Geun , Benson David , Jagannathan Kaushik , Robinson David B.
Published: February 2020

Abstract not Available.
Conformal Electroless Deposition On monolayers for TSV Applications
Authors: Cervati Michele , Carnevali Guido , Armini Silvia , Magagnin Luca
Published: February 2020

Abstract not Available.
The Application of Nico Alloy Electroforming On Products With Microstructure
Authors: Chen Hsi-Jhu
Published: February 2020

Abstract not Available.
A Highly Sensitive Hybrid Film Sensor for Voltammetric Detection of Calcium Antagonist Cilnidipine
Authors: Jain Rajeev , Kumar Dhanjai
Published: February 2020

Abstract not Available.
Quasi-Solid-State Dye-Sensitized Solar Cells Assembled With Polymer Electrolyte Containing Core-Shell Structured Polymeric Ionic Liquid
Authors: Jo Sung-Geun , Kim Dong-Won
Published: February 2020

Abstract not Available.
Catalytic Oxidation of Liquid Fuels On Palladium Nanoparticles Loaded Carbon Nanotubes
Authors: Wan Qijin , Han Mingzhen , Liao Hualing , Yang Nianjun
Published: February 2020

Abstract not Available.
(Invited) Modified Copper Tungstate Photoanodes For Efficient Solar Driven Water Oxidation
Authors: Herring Andrew M , Pilli Satyander Kishore , Turner John A , Deutsch Todd G , Furtak Thomas E.
Published: February 2020

Abstract not Available.
Progress in the Combinatorial Search for Semiconducting Oxides That Photoelectrolyze Water
Authors: Skorupska Katarzyna , Parkinson Bruce A
Published: February 2020

Abstract not Available.
(Invited) Photovoltaic Designs For Integrated and Spontaneous Solar Water Splitting
Authors: Ager Joel W.
Published: February 2020

Abstract not Available.
(Invited) A Study Of Interfacial Processes Between Metal Oxide Nanostructured Thin Films and Ionic Liquids For Potential Applications In Photoelectrochemistry
Authors: Santato Clara , Pison Jonathan , Isik Dilek , Sivalingam Yuvaraj , Sayago Jonathan
Published: February 2020

Abstract not Available.
δ-MnO2 Supported On Carbon Nanotubes for Photocatalytic Water Splitting
Authors: Nakayama Masaharu , Mito Shunsuke , Yoshimura Kazumasa , Mohri Yasuharu , Shamoto Mitsuhiro
Published: February 2020

Abstract not Available.
Highly Efficient Photoelectrochemical Hydrogen Production Using CdS/CdSe Co-Sensitized TiO2 Nanorod Array Photoelectrode
Authors: Han Hyun Soo , Shin Sun , Kim Ju Seong , Cho In Sun , Hong Kug Sun
Published: February 2020

Abstract not Available.
Quantitative Decoding of Ammonia-Hydrocarbon Mixtures Using Zirconia-Based Mixed Potential Sensors
Authors: Kreller Cortney R. , Tsitron Julia , Sekhar Praveen K. , Mukundan Rangachary , Garzon Fernando H , Morozov Alexandre V , Brosha Eric L.
Published: February 2020

Abstract not Available.
Amperometric Gas Sensors in Agricultural Applications
Authors: Carter Michael T , Stetter Joseph R , Findlay Melvin W , Patel Vinay
Published: February 2020

Abstract not Available.
Electrochemical Characterization of Screen Printed Au Electrodes
Authors: Huang Qiang , Baker-O'Neal Brett , Ahmed Shafaat
Published: February 2020

Abstract not Available.
Impedance As a Diagnostic Tool to Characterize Mixed-Potential Sensor Response
Authors: Kreller Cortney R. , Sekhar Praveen K. , Spernjak Dusan , Li Wenxia , Palanisamy Ponnusamy , Brosha Eric L. , Mukundan Rangachary , Garzon Fernando H
Published: February 2020

Abstract not Available.
Development of All-Solid Thin Film Electro-Chromic Devices and Applications
Authors: Panchal Chetan J. , Khosla Ajit
Published: February 2020

Abstract not Available.
Synthesis of Conjugated Materials for Organic Photovoltaics and Luminescence
Authors: Výprachtický Drahomír , Pokorná Veronika , Kmínek Ivan , Dzhabarov Vagif , Cimrová Věra
Published: February 2020

Abstract not Available.
Glycothermal Synthesis and Characterization of YAG:Ce3+ Nanophosphors
Authors: Isobe Tetsuhiko
Published: February 2020

Abstract not Available.
Effect of Synthesis Methods On the Powder Characteristics and Luminescence Properties of Nanophosphors
Authors: Han Jinkyu , Choi Jae Ik , Talbot J. B. , Lee John Seung-Hyo , McKittrick Joanna
Published: February 2020

Abstract not Available.
Prediction of Pressure Dependence of R-Line Emission for d3 Ions in α-Al2O3 Based On First-Principles Calculations
Authors: Novita Mega , Ogasawara Kazuyoshi
Published: February 2020

Abstract not Available.
First-Principles Calculations of 4f-5d Transition Spectra for Ce3+ in Silicate Garnets
Authors: Haji Eman , Novita Mega , Ogasawara Kazuyoshi
Published: February 2020

Abstract not Available.
Microstructure and Optical Properties of An Oxynitride Ceramic Phosphor
Authors: Raukas Madis , Hannah Mark E , Johnston David , Montaner Jason , Yu Zhengbo , Tragl Sonja , Rucki Andreas , Klueppel Veronika , Jones Eric , Zhou Xiang , Wang Mingsheng , Gradecak Silvija
Published: February 2020

Abstract not Available.
Synthesis of Yellow-Emitting NaAlSiO4:Eu2+ Phosphors Using Sio Powder As a Silica Source
Authors: Toda Kenji , Abe Takeshi , Ishigaki Tadashi , Kim Sun Woog , Uematsu Kazuyoshi , Sato Mineo , Masaki Takaki , Yoon Dae Ho
Published: February 2020

Abstract not Available.
Conversion Reactions in Li-FeF2 Cathodes
Authors: Garofalini Stephen H. , Ma Ying
Published: February 2020

Abstract not Available.
SECM Dissolution Studies of Pasted Battery Cathodes in Ionic Liquid Electrolytes
Authors: Snook Graeme Andrew , Huynh Thuy Diem , Best Adam Samuel
Published: February 2020

Abstract not Available.
Effect of Carbon Additives On the Microstructure and Conductivity of Primary Alkaline Battery Cathodes
Authors: Nevers Douglas R. , Wen Yuan , Robertson Logan , Wheeler Dean R.
Published: February 2020

Abstract not Available.
Doped MnO2-Based Oxygen Reduction and Evolution Catalysts for Bifunctional Cathodes in Alkaline Electrochemical Power Sources
Authors: Hosseini Benhangi Pooya , Alfantazi Akram , Gyenge Elod
Published: February 2020

Abstract not Available.
A Metal-Free, Lithium-Ion Oxygen Batteries for Improving Safety
Authors: Park Jin-Bum , Kwak WonJin , Shin Chang Dae , Park Gang-Jun , Sun Y.-K. , Scrosati Bruno
Published: February 2020

Abstract not Available.
Non-enzymatic electrochemical sensor technology basedon vertically aligned 3-D nanowire array platform
Authors: Razeeb Kafil
Published: February 2020

Abstract not Available.
A Review of Single-Cell Manipulation Techniques for Microfluidic Lab-On-a-Chip Systems
Authors: Romanuik Sean F. , Gray Bonnie L.
Published: February 2020

Abstract not Available.
Keynote--Using Experience From Explosives Detection in Development of Biosensors Based On Nanomechanical Responses
Authors: Boisen Anja
Published: February 2020

Abstract not Available.
Electrochemical Synthesis of PolymerNanostructures for Thermal Management
Authors: Cola Baratunde
Published: February 2020

Abstract not Available.
Electropolishing of n-Type Polycrystalline 3C-Silicon Carbide
Authors: Ballarin Novella , Carraro Carlo , Maboudian Roya , Magagnin Luca
Published: February 2020

Abstract not Available.
Vapor-Solid Growth of Highly Oriented SnO2 Nanorods for Chemical Sensing Applications
Authors: Carvajal Christian G , Pradhan Aswini K , Davis Candace S
Published: February 2020

Abstract not Available.
Nanobiosensing Technology for Foodborne Pathogen and Toxin Detection
Authors: Park Bosoon
Published: February 2020

Abstract not Available.
A Step Towards a Discriminative Neurotoxin Biosensor: Guarding of Acetylcholinesterase From Organophosphate Compounds
Authors: Zhang Yuanyuan , Kirsch Jeffrey , Arugula Mary , Simonian Aleksandr
Published: February 2020

Abstract not Available.
Electrode Performance of Lithium Containing Layered Sodium Iron Manganese Oxides for Rechargeable Na-Ion Batteries
Authors: Kubota Kei , Kaneko Takafumi , Yabuuchi Naoaki , Hara Ryo , Komaba Shinichi
Published: February 2020

Abstract not Available.
NaCrO2 Cathode for Rechargeable Sodium Ion Batteries
Authors: Myung Seung-Taek , Yoo Chan-Yeop , Sun Y.-K.
Published: February 2020

Abstract not Available.
The Role of Metal Catalysts in the Electrochemistry of the Lithium-Air Battery - a Solid State NMR Study
Authors: Moore Amy J , Leskes Michal , Ball Sarah , Potter Robert , Grey Clare P.
Published: February 2020

Abstract not Available.
Advanced Sodium-Ion Rechargeable Battery Based On a Sn/C Anode and Layered Oxide Framework Cathode
Authors: Oh Seung-Min , Myung Seung-Taek , Hwang Jang Yoen , Scrosati Bruno , Hassoun Jusef , Sun Y-K.
Published: February 2020

Abstract not Available.
Continuum-Scale Modeling of Lithium-Air Batteries
Authors: Liu Jing , Monroe Charles
Published: February 2020

Abstract not Available.
Non-Aqueous Mg Electrochemistry for Rechargeable Batteries
Authors: Aurbach Doron , Yoo Hyun Deog , Shterenberg Ivgeni , Gofer Yosef
Published: February 2020

Abstract not Available.
Electrode-Electrolyte Solution Interactions Between TiO2 Nanotube Electrode and Nonaqueous Electrolytes for Sodium-Ion Batteries
Authors: Xiong Hui (Claire)
Published: February 2020

Abstract not Available.
Surface Studies of Na2Ti3O7 Electrodes for Rechargeable Sodium-Ion Batteries
Authors: Muñoz Márquez Miguel Ángel , Zarrabeitia Maider , Castillo-Martínez Elizabeth , Eguía Aitor , Rojo Teófilo , Casas-Cabanas Montserrat
Published: February 2020

Abstract not Available.
Pt Nanoparticle Deposited α-MnO2 Nanotube: A Higher Active Electrocatalyst for Li–O2 Batteries
Authors: Liu Jia , Zhu Jiefang , Gustafsson Torbjörn , Edström Kristina
Published: February 2020

Abstract not Available.
Li/Lipon/Li-Conducting Glass Ceramic Composite for Li-Air Batteries With Non-Aqueous Electrolyte
Authors: Jadhav Harsharaj S. , Kalubarme Ramchandra S. , Kim Yong-Han , Park Chan-Jin
Published: February 2020

Abstract not Available.
Optimization of Block Copolymers As Electrolytes for Lithium Metal Batteries
Authors: Bouchet Renaud , Devaux Didier , Gle David , Phan Trang N. T. , Gigmes Didier , Deschamps Marc
Published: February 2020

Abstract not Available.
Toward Fully Plastic Batteries: Electroactive Polymer-Carbon Composite Electrodes for Rechargeable Batteries
Authors: Esat Burak , Bahceci Sumeyye , Aydin Muhammed , Akay Sevda
Published: February 2020

Abstract not Available.
Study of the Strain Evolution of Lithium-Ion Cells to Provide a State of Charge and State of Health Indicators
Authors: Geniès Sylvie , Coutier Caroline , Mailley Sophie , Alias Mélanie
Published: February 2020

Abstract not Available.
Safer Electrolyte for Lithium-Ion Batteries
Authors: Park Chi-Kyun , Rubino Robert
Published: February 2020

Abstract not Available.
Ionic Liquid-Nanoparticle Hybrid Electrolytes and Their Applications in Rechargeable Lithium Metal Batteries
Authors: Lu Yingying
Published: February 2020

Abstract not Available.
FT-IR Measurements of Generative Gas From Lithium-Ion Batteries At Abuse Temperature
Authors: Koike Shinji , Shikano Masahiro , Sakaebe Hikari , Kobayashi Hironori
Published: February 2020

Abstract not Available.
Computational Thermodynamics for Material Design of Energy Storage Materials
Authors: Markus Torsten
Published: February 2020

Abstract not Available.
Improved Low Temperature Performance of Supercapacitors
Authors: Brandon Erik J. , Smart Marshall C. , West William C. , Gnanaraj Joe
Published: February 2020

Abstract not Available.
Electrochemical Properties Enhancement of Flexible Textile Based Supercapacitor
Authors: Yun Tae Gwang , Oh Minsub , Hyun Seungmin , Han Seung Min
Published: February 2020

Abstract not Available.
Cycle Behavior of Aqueous and Nonaqueous Vanadium Oxide Electrochemical Capacitors
Authors: Engstrom Allison M , Doyle Fiona M
Published: February 2020

Abstract not Available.
Lanthanum Based Perovskites Exhibiting Hydroxide Ion Storage for Pseudocapacitor Electrodes
Authors: Mefford J. Tyler , Hardin William G. , Dai Sheng , Johnston Keith P. , Stevenson Keith J.
Published: February 2020

Abstract not Available.
One-Step Synthesis of Co(OH)2/Graphene Nanocomposites From Graphite for Electrochemical Supercapacitors
Authors: Lee Hae-Min , Jeong Gyoung Hwa , Kim Sang-Wook , Kim Chang-Koo
Published: February 2020

Abstract not Available.
Preparation of Highly Porous Carbon from Resins after the Treatment of Wastewater Containing Heavy Metal Ions for Supercapacitors
Authors: Lu Zhou Guang
Published: February 2020

Abstract not Available.
Development of a Prototype of Supercapacitor Based On Activated Carbon and a Neutral Aqueous Electrolyte
Authors: Di Blasi Orazio , Staiti Pietro , Lufrano Francesco , Antonucci Vincenzo , Brigandi Antonino
Published: February 2020

Abstract not Available.
Half- and Full-Cell Performance of Silicon-Carbon Anodes Using the Capacity Control Method
Authors: Karulkar Mohan , Wen Hao , Adams Jim
Published: February 2020

With the demand for electric vehicles increasing, the need for higher energy and power density in automotive batteries is apparent. Silicon-carbon composites represent promising anode materials, striking a balance between the stability of graphite and the high capacity of pure silicon. However, cycle life and current density remain too low when considering practical applications and real-world automotive targets.

C-Si anodes are typically examined in half-cell applications, being cycled against a lithium counterelectrode. However, Li is a poor metal for cycling, and has the potential to confound cycle life data as mossy Li grows and increases cell impedance. Figure 1 shows the results of Li-Li cycling, and indicates approximately linear relationships between percent lithium lost and cycle life. To get a more straightforward assessment of C-Si anodes, full cell testing has been performed, and compared to half-cell cycling against lithium. Cycle life, capacity, and other performance metrics will be examined.

Several innovations have been demonstrated to improve C-Si anode performance.[1] The Capacity Control Method has been demonstrated as an effective means to improve cycle life and current density (Figure 2). Additionally, the Conductive Dual Cast technique has been shown to improve capacity (Figure 3). Both of these techniques have been more thoroughly explored in the present work, and a relationship between capacity cutoff, current density, and cycle life has been established.

Deviations from the Si-C half-cell ideal are examined in the context of energy and power density. For instance, the effect of pairing high-capacity C-Si with lower-capacity intercalation cathodes is investigated using modeling and the full-cell testing from above. The costs and benefits of conductive layers, which add thickness and weight to the anode, are discussed. Finally, the effect of Capacity Control method, which by design underutilizes C-Si anodes, is analyzed in relation to real-world automotive targets.

[1] M. Karulkar, R. Blaser, R. Kudla, Electrochemical Society 224th Meeting, San Francisco, Abstract 227 (2013).
Electrochemical Study of Cobalt Salen Compounds for Catalytic Biomass Degradation
Authors: Servedio Luke T. , Foister Shane , Bozell Joseph , Zawodzinski Thomas A.
Published: February 2020

ABSTRACT

Heightened interest in sustainable energy sources have led to a multitude of forays into technologies dealing with biomass refining and energy conversion. While certain streams of biomass offer attractive possibilities as a virtually limitless feedstock, the inherent complexities associated with the constituent biomass polymers, especially the heterogeneous lignin polymer make efficient processing a difficult problem. To make efficient use of lignin as a potential feedstock for energy production or as a chemical precursor, high catalytic specificity and yield is desirable to deal with a broad range of chemical linkages in a manner that results in a single (or few) product(s). In this study, we investigate the use of organometallic Cobalt (salen) complexes and their application toward catalytic breakdown or modification of the lignin polymer. Various lignin model compounds have been used to study possible modes of converting lignin into a usable product in batch reactions with mixed results. In nearly all studies, regardless of yield, the catalyst undergoes deactivation, likely due to an irreversible conformational change or a change in oxidation state of the metal center.

By employing non-aqueous cyclic voltammetry, we show that unfixed Co(salen) complexes form a highly reversible redox system. The largely conserved shape of the electrochemical response over successive scans suggests that these catalysts may be recoverable within an electrochemical redox system. Using lignin monomer analogs, we studied electro-catalytic reactions utilizing half-cell cyclic voltammetry and various other characterization techniques to study the electrochemical reversibility of the system and examine the reaction mechanism and oxidation products. Depending on the relative rates of the chemical reaction step and the characteristic response to CV scan rate, the catalytic process defined by the electrochemical oxidation of the catalyst and subsequent chemical reaction step between the ‘activated’ catalyst and the substrate should lead to a “steady state” response similar to that observed for a mass transport limited system. Chemical characterization techniques were also utilized to probe the catalyst oxidation state changes throughout the reaction in an attempt to resolve some of the issues of system deactivation.

Keywords
: lignin, cobalt salen, electrochemical oxidation, non-aqueous cyclic voltammetry

ACKNOWLEDGEMENT

We gratefully acknowledge the support of the University of Tennessee Office of the Vice President for Research for support of this work.
Application of Supercritical CO2 Emulsified Electrolyte in Cathodic Deposition of Metal Oxides
Authors: Chang Tso-Fu Mark , Lin Wei-Hao , Hsu Yung Jung , Sato Tatsuo , Sone Masato
Published: February 2020

Metal oxides, such as TiO2 and ZnO, have been extensively investigated to foster their applications in various technologically important fields. There are many synthetic approaches proposed to fabricate metal oxide thin films. Among the different synthetic routes, electrochemical deposition affords an effective process for production of metal oxide thin films. Properties of the metal oxide films are highly dependent on desorption of gas generated on the surface of cathode, which can affect the pore structure of the porous metal oxide films deposited. Generation rate of hydroxyl ions on the surface of cathode and removal rate of the hydroxyl ions away from the surface of cathode can affect local pH on the surface cathode, which can affect grain size of the metal oxide formed.

Supercritical CO2 (sc-CO2) emulsified electrolyte (SCE) is known to be effective in affecting desorption rate of gas formed on the surface of cathode, and influence transfer efficiency of reactive species to the surface of cathode. Therefore, properties of the TiO2 and ZnO thin films are expected to be influenced by the properties of the emulsion.

In this work, a sc-CO2-assisted galvanostatic cathodic deposition process is developed for preparation of TiO2 and ZnO thin films with high structural uniformity. TiO2 and ZnO are deposited cathodically on a conductive substrate in a two-compartment cell under a fixed current density, in which platinum foil is employed as the counter electrode. Influences of sc-CO2 and reaction pressure on the crystal growth of TiO2 and ZnO thin films were investigated. The present synthetic approach could be further extended to obtain other metal oxide thin films such as SnO2, CuO, NiO and so on.
Electrochemical Characterization of Pt Nanocatalysts Supported on Functionalized Vulcan Xc-72 for the EOR
Authors: Pech-Rodríguez W.J. , Gonzalez-Quijano D. , Vargas-Gutierrez G. , Escalante-Garcia J.I. , Rodriguez-Varela F.J.
Published: February 2020

In this work, the effect of the functionalization of Vulcan support on the electrocatalytic behavior of Pt/C nanocatalysts for the Ethanol Oxidation Reaction (EOR) has been studied. Vulcan was functionalized via a micro-wave reaction using citric acid and methanol as chemical agents. Pt nanoparticles were dispersed on functionalized Vulcan using the Intermittent Microwave Heating reduction method.
Synthesis of Ordered Mesoporous Carbon As Support for Pt-Co Alloys: Evaluation As an Alcohol-Tolerant ORR Catalyst for Direct Oxidation Fuel Cells
Authors: Morales-Acosta D. , Rodriguez-Varela F.J.
Published: February 2020

One of the most important drawbacks for the commercialization of low temperature Direct Oxidation Fuel Cells (DOFCs) is the crossover of liquid fuels through commercially available polymer electrolyte membranes. In these cells Pt-alone electrocatalyst is rapidly poisoned by such substances and/or their intermediates. The investigations on this matter include the development of tolerant cathodes based on Pt alloys which have shown a high catalytic activity for the ORR. Ordered Mesoporous Carbon (OMC) has received great attention because of their potential use as electrocatalysts support for fuel cell electrodes due to their relatively large pores that facilitate mass transfer, and their very high surface area, which allows a high concentration of active sites per mass of catalyst. OMC was synthesized via self-assembly in aqueous phase using Resorcinol/Formaldehyde as carbon precursors, followed by pyrolysis at high temperature. Pt-Co catalysts supported on OMC (Pt-Co/OMC) were synthesized by the polyol reduction process. Pt-Co/OMC catalyst was characterized by X-ray diffraction, scanning electron microscope-energy dispersive X-ray analysis, and transmission electron microscopy techniques. The electrocatalytic behavior for the ORR was investigated in rotating disk electrode configuration in an acidic medium. In the presence of the different liquid fuels (ethanol, ethylene glycol or 2-propanol), the alloys show a high degree of tolerance. The results obtained from the Pt-Co/OMC electrocatalysts were compared to those of a Pt/OMC cathode.
Nanostructured Gold-Nickel/Titania Nanotubes Electrocatalysts for Hydrazine Oxidation
Authors: Tamasauskaite-Tamasiunaite Loreta , Rakauskas Justinas , Balciunaite Aldona , Zabielaite Ausrine , Vaiciuniene Jurate , Selskis Algirdas , Norkus Eugenijus
Published: February 2020

This work is focused on the study of self-ordered titania nanotube arrayed electrodes for preparation of efficient nanostructured gold-nickel/titania nanotubes (denoted as Au(Ni)/TiO2-NTs) electrocatalysts for the oxidation of hydrazine in alkaline medium. Titania nanotube arrayed substrate was applied for preparation of catalysts due to its high cation exchange capacity, which provides the possibility of achieving a high loading of active catalyst with an even distribution and high dispersion. The self-ordered TiO2 nanotube arrays were prepared by anodic oxidation of Ti surface in an aqueous sulfuric acid solution containing some NH4F. The average tube diameter was ~100 nm and the thickness of titania layers was ~350 nm. Gold nanoparticles in size of ~10-30 nm were deposited on the surfaces of titania nanotube arrays by partial galvanic displacement of electroless nickel layer that had been previously deposited. The electroless Ni-P layer with the thickness of ~300 nm was deposited on the titania nanotubes surface, which produces a layer of granular nickel particles ~200 nm in size.

The morphology, structure and composition of the prepared nanostructured catalysts were examined by field emission scanning electron microscopy, energy dispersive X-ray analysis and inductively coupled optical emission spectroscopy. The electrocatalytic activity of the prepared catalysts was investigated towards the oxidation of hydrazine in alkaline medium by means of cyclic voltammetry and chronoamperometry.

Data on the pecularities of various electrodes are compared and discussed on the basis of electrochemical data. The prepared Au(Ni)/TiO2-NTs catalysts with different Au loadings possesses a higher electrocatalytic activity towards the oxidation of hydrazine in alkaline medium as compared to that of TiO2-NTs and Au deposited electrochemically on the TiO2-NTs and seem to be a promising anode materials for direct hydrazine fuel cells.

Acknowledgment

J. Rakauskas acknowledges support by project "Promotion of Student Scientific Activities" (VP1-3.1-ŠMM-01-V-02-003) from the Research Council of Lithuania. This project is funded by the Republic of Lithuania and European Social Fund under the 2007-2013 Human Resources Development Operational Programme’s priority 3.
On the Controversial Role of the Metal in Fe/N/C or Co/N/C Electrocatalysts for the Reduction of Oxygen in the Acidic Medium of PEM Fuel Cells
Authors: Dodelet Jean-Pol
Published: February 2020

The proton-exchange membrane hydrogen/air (PEM) fuel cell constitutes an efficient and environmentally-harmless alternative to the gasoline-dependent technology used today for transportation. However, the replacement of platinum-based catalysts, used at their electrodes and accounting for a large fraction of the fuel cell stack cost, is one of their challenges to reach full commercialization.

Today, Fe/N/C-catalysts and perhaps also Co/N/C-catalysts obtained from the pyrolysis of molecular precursors are the most promising non-platinum-group-metal (non-PGM) catalysts for the electrochemical reduction of oxygen (air) to water in an acidic medium such as that of PEM fuel cells.

Despite decades of research on Fe- (or Co) -based electrocatalysts for the oxygen reduction reaction (ORR), the role of the metal is still one that raises a great deal of controversy. Consequently, the nature of the catalytic site in these non-noble metal ORR catalysts is still a topic of debate. One camp within the scientific community believes that the metal is an integral and electrochemically active part of the catalytic site, while the other believes that the metal is merely a chemical catalyst for the formation of special oxygen-reducing N-doped carbon structures.

After presenting the case for the importance of non-noble catalysts at the cathode of PEM fuel cells, we will introduce the three models of active sites that were advocated during the 1980’s by van Veen, Yeager, and Wiesener, and discuss how they have evolved, especially that of Yeager. Wiesener’s model will be analyzed in detail through the work of several research groups that have been staunch supporters.

It will be shown that all the active sites proposed by van Veen, Yeager and Wiesener in the 1980’s, while different, are in fact simultaneously present in Fe- (or Co)-based catalysts active for ORR in acidic medium, except that their activity and relative population in these catalysts is different, depending on the choice of the metal precursor, nitrogen precursor, structural properties of the carbon support and the synthesis procedure.

A good knowledge of the nature and structure of the catalytic sites is important to further improve catalyst activity and site stability, especially for the Fe/N/C cathode catalysts that lead to the highest power densities reported to date for non-PGM-based catalysts able to reduce oxygen at meaningful cell voltages in PEM fuel cells.
Kinetic Modeling and Simulated Performance of CO and Syngas Electro-Oxidation in Ni-YSZ Solid-Oxide Fuel Cells
Authors: Hanna Jeff , Ghoniem Ahmed F
Published: February 2020

The use of solid-oxide fuel cells for the conversion of gasified solid carbon is receiving a great deal of interest, and they have long been considered for the conversion of hydrocarbon reformates. Regardless of the original fuel source, the major species involved in current-producing electrochemical reactions at three-phase interfaces are likely to be hydrogen and carbon monoxide. One or both of these species may be present and participating in charge transfer and reforming depending on operating conditions, catalyst selection, system design, and so on. While the elementary steps of H2 electrochemical conversion in Ni-YSZ anodes have been known for almost a decade, the reaction kinetics are only now coming to light. The steps governing electro-oxidation of CO, on the other hand, are not yet agreed upon. It is important that we understand the conversion pathways of H2 and CO individually, so that SOFC systems reliant on one of these species can be better understood and optimized. In this work, a mathematical and computational model is developed around the framework of a reduced mechanism describing electrochemical oxidation of CO and syngas mixtures on Ni-YSZ anodes. We analyze the most likely species to exist on the catalyst and electrolyte surfaces, the interactions between them, and different charge-transfer pathways in the context of steady-state and transient models. The most likely mechanisms are subsequently included in a homogenized porous-electrode model to compare simulated performance and polarization characteristics to measured results in SOFC button-cell experiments using CO-CO2 and H2-H2O-CO-CO2 mixtures.
Identifying Water Saturation of Various Layers in PEMFCs through EIS and X-ray Radiography
Authors: Antonacci Patrick , Lee Jongmin , Yip Ronnie , Ge Nan , Kotaka Toshikazu , Tabuchi Yuichiro , Bazylak Aimy
Published: February 2020

Polymer electrolyte membrane fuel cells (PEMFCs) are a growing technology that makes use of electrochemical energy for many practical applications. Energy is converted from electrochemical to electrical and thermal energy through the process of oxygen-reduction and hydrogen-oxidation, with water as a by-product. The performance of the fuel cell is heavily influenced by the mass transport capabilities of the water produced through this electrochemical reaction [1]. In order to understand the performance of specific fuel cell builds, it is important to develop a diagnostic tool which offers an accurate depiction of the amount of liquid water in the fuel cell during operation. Two of these diagnostic tools are electronic impedance spectroscopy (EIS) and synchrotron X-ray radiography. For this study, X-ray radiography was performed at the Biomedical Imaging and Therapy Bending Magnet (05B1-1) beamline at the Canadian Light Source Inc. (Saskatoon, Canada).

In order to quantify the amount of liquid water in a PEMFC during operation, X-ray radiography was applied in the through-plane direction of the cell. Using the Beer-Lambert law, the processed images allowed for the liquid water to become visible in the anode and cathode flow channels, the anode and cathode gas diffusion layers (GDLs), the microporous layers (MPLs), as well as the membrane electrode assembly (MEA) [2]. EIS was used as a non-invasive diagnostic tool in quantifying the equivalent resistances of the fuel cell. This study aims to quantify the water saturation of various layers of the fuel cell during EIS measurements, and demonstrate the role of the water saturation of each layer to the overall mass transport resistance of the fuel cell, measured through EIS. The fuel cells analyzed have varying MPL thicknesses, as well as fuel cells without MPLs, at increasing constant current densities. Nyquist plots will be discussed with relation to amount of liquid water visualized.

Figure Captions

Figure 1. Subtracted in-plane image of the fuel cell with 150 μm-thick MPL. The image only shows 3 flow channels of 20.

Figure 2. Nyquist plot of the fuel cell observed simultaneously with x-ray radiography 1.0 A/cm2.

Figure 3. Water thickness profile plot at 1.0 A/cm2, from the image in Figure 1. Labeled from left to right: Anode GDL, Anode MPL, MEA, Cathode MPL and Cathode GDL.

References

[1] D. Malevich, E. Halliop, B. Peppley, J. Pharoah, and K. Karan, Journal of the Electrochemical Society 156 (2) B216 – B224 (2009)

[2] J. Hinebaugh, J. Lee, and A. Bazylak, Journal of Electrochemical Society 159 (12) F826-F830 (2012)
Comparison of Water Transport Mechanisms Between Commercial and Experimental Virgin and Aged Diffusion Media Using High Resolution Neutron Radiography
Authors: LaManna Jacob M , Mench Matthew M.
Published: February 2020

The motivation of this work is to characterize water transport for a new high tortuosity anode diffusion media (DM) and to provide the modeling community with valuable benchmark validation data. The high resolution neutron images in this work were taken at the Neutron Imaging Facility at the National Institute of Standards and Technology (NIST) Center for Neutron Research. Tests were conducted with well-defined boundary conditions and publically available materials. Gradients in pressure, inlet relative humidity, and temperature were used to isolate hydraulic, diffusion, and temperature driven flow through the membrane and porous media.

A custom designed 4.8 cm2fuel cell with liquid coolant for precise thermal boundary conditions was used to acquire the neutron images. Test conditions were selected to produce extreme gradients within the cell to push model prediction capabilities. The high resolution neutron images allow for the determination of through-plane water profiles and water transfer rates as a function of current density as shown in Figure 1. Additionally, real-time water balance and net water drag measurements were made with dew point sensors.

This talk will discuss the differences in performance and water content of the experimental DM and baseline commercial DM presented previously, and attempt to draw conclusions relating the structural properties of the porous media and resulting performance and water transport and distribution. Additionally, partially degraded materials (e.g. electrodes used for hundreds of hours) will be compared to virgin materials to understand the impact of age and lifetime on water transport and performance. Data from this work will build upon an online database of benchmark data for the modeling community made available through this Department of Energy EREE supported program.

Acknowledgements

This work is funded by the United States Department of Energy Efficiency and Renewable Energy (EREE) Program through General Motors under Award Number DE-EE0000470. The authors would like to thank Dr. Dan Hussy and Dr. David Jacobson of NIST for their guidance.

Figure 1: Liquid water profiles for all 1.5 A/cm2 test conditions for baseline DM (upper) and high tortuosity DM (lower). The high tortuosity DM significantly reduces anode water content for identical operating conditions to baseline.
In Situ Observation of Epitaxial Li-Si-Nanostructure Formation on Si(111)
Authors: Grosse Frank , Proessdorf Andre , Hanke Michael , Bierwagen Oliver
Published: February 2020

Silicon is considered as anode material for Li-ion batteries due to its high theoretical capacity with a value of 4200 mAh/g for Li22Si5. The associated volume change exceeding 300 % during de-/lithiation of silicon is considered as the major problem for application with a possible solution in using nanostructured material. Various details of the formation of Li-Si phases are presently under discussion like the formation of amorphous vs. crystalline structures or the Li-Si phase order during lithiation.

To shed light on the relevant processes during the Li-Si phase formation a clean Si substrate was exposed under ultra-high condition in a molecular beam epitaxy (MBE) environment to an atomic lithium flux. During the experiment the Si substrate temperature was gradually reduced from initial 700°C down to room temperature. Simultaneously, the onset of the nucleation and the formation of Li-Si phases were observed by in situ synchrotron x-ray diffraction (XRD), azimuthal reflection high-energy electron diffraction (ARHEED), and line-of-sight quadrupole mass spectrometry (QMS) of the desorbing Li. Initial only Si surface reconstructions are observed involving only the top most atomic layer. At lower temperatures, Li-Si nanostructures are formed. First, crystalline Li12Si7 appears, followed by the formation of Li21Si5 phases. Both phases grow epitaxially. The epitaxial relationship is Si[111]||Li12Si7[010] and Si[11-2]||Li12Si7[100] as well as Si[111]||Li21Si5[111] and Si[01-1] ||Li21Si5[01-1]. Further confirmation besides the XRD data is gained by investigating the Li-Si surfaces. The Li21Si5(111) surface exhibits an approximately nine times larger (1x1) surface unit cell than the unreconstructed Si(111) surface. Ex situ investigations of various intermediate stages of the Li-Si phase formation by atomic force microscopy show nanostructures which formed on the substrate surface with a height of about 10 nm and 100 nm diameter much smaller than usually reported in Si anode material. It demonstrates that the formation of the Li-Si phases depends on the Li kinetics as well as the Si release mechanism from the crystalline substrate and its diffusion.

Acknowledgements: This work was supported by the Leibniz-Gemeinschaft under the project No. SAW-2011-PDI-230. The experiments are carried out at the synchrotron radiation facility Bessy II (Helmholtz-Zentrum Berlin, Germany).
In Silico Based Rank Order Determination of Electrolytes for Sodium Ion Battery Applications
Authors: Kamath Ganesh , Cutler Richard , Parrish Riley , Xiong Hui (Claire) , Sankaranarayanan Subramanian
Published: February 2020

The selection of an appropriate electrolyte is an important consideration in the design of next-generation batteries. Low-cost sodium ion based batteries have assumed the role of attractive alternatives to Lithium ion batteries for dispensing and storage of energy. Here, we perform in silico based molecular dynamics simulation (MD) study on a variety of electrolytes and NaClO4 salt. We perform potential of mean force (PMF) calculations to extract the free energy of solvation for these different electrolyte-salt combinations in bulk and rank them based on the free energy predictions. The energetics of ion solvation will be used to understand the surface preference of the intercalating ion for a given electrolyte. The PMF calculations will provide insights into the solubility of the salt in the various electrolytes and will serve as a metric for choosing the most suitable electrolyte-salt combination for a given electrode. In designing new electrolytes, it is generally preferred to have high solubility of the salt. We will also determine the heats of vaporization of the various organic electrolytes and this information will be used to identify the operational range and safety aspects of the electrolyte. Electrolytes with low heat of vaporization can be considered unsafe. Additionally, the MD simulation trajectories will also be used to calculate the diffusivity of the ions in the various electrolytes. Additional transport metrics such as activation barriers to diffusion, ionic conductivity are used to refine the rank order of the electrolytes, in addition to the thermodynamics and equilibrium considerations. Determination of micro-structure suggests varying degree of coordination of sodium ion with these electrolytes commensurate with the ion solvation energetics. Suitable comparisons of computational predictions are made with experimental resutls. Collectively, this would form an apriori, in silico study informing experiments and would be a useful tool and metric for screening variety of solvent and electrode candidates in terms of their ability to be used for battery applications.
Microstructural Effects in Textured Neodymium Doped Ceria
Authors: Baure George , Sulekar Soumitra S. , Nino Juan C.
Published: February 2020

Neodymium doped ceria (NDC) is a promising candidate for use as an electrolyte in a solid oxide fuel cell (SOFC) due to its high ionic conductivity, low electronic conductivity, and good sinterability and stability. It is well known that grain size and grain boundary effects can significantly impact the observed ionic conductivity of ceria in the bulk and particularly in thin films. This work focuses on the influence grain size (film thickness) and grain boundary configuration have on the ionic conductivity of NDC. To this end, textured NDC thin films of varying thicknesses and grain sizes were grown on sapphire substrates using pulsed laser deposition (PLD). We will present broadband impedance data analysis on across plane and in-plane electrode configurations collected as a function of temperature. The separate effects of film thickness, grain size, and grain boundary on the observed ionic conductivity will be discussed based on the contrasting data from the two measurement configurations.
Development of Redox-Switchable Organocatalysts
Authors: Suga Seiji , Takasuka Yuki , Onishi Yuki , Okamura Yuuya , Fujiwara Ikumi , Kurihara Yuusuke , Kawakami Mai , Mitsudo Koichi
Published: February 2020

Redox-switchable catalysis is an emerging research field that seeks to regulate chemical reactions by the simple reduction-oxidation manipulation. The modulation of electron density of redox-responsible ligands in the transition metal catalyzed reactions by changing oxidation state was usually used to control catalytic activity. Meanwhile, we have developed the cation pool method which involves generation and accumulation of organic cations in relatively high concentration.For example, the accumulation of an organo-dication 2 has been accomplished by the electrochemical oxidative C-C bond cleavage of compound 1 at low temperature (Scheme 1).1) The carbocations having two electron deficient carbon centers are expected to serve as effective Lewis acids, and we revealed that several reactions such as Mukaiyama-Aldol reaction,2) Diels-Alder reaction, and Nazarov cyclization, were significantly promoted by a catalytic amount of the organo-dications in a highly efficient manner (Scheme 2). We are highly motivated to investigate the utility of the dications as redox-switchable catalysts, and revealed the possibility to modulate Mukaiyama-Aldol reaction by using the reaction system (Scheme 3).

1) Okajima, M.; Suga, S.; Itami, K. Yoshida, J. J. Am. Chem. Soc.
2005, 127, 6930-6931.

2) Mukaiyama, T.; Kobayashi, S.; Murakami, M. Chem. Lett.
1984, 1759-1762.
An Electrochemical Etching Process for Flow Battery Structures to Improve Performance and Reduce Manufacturing Cost
Authors: McCrabb Heather , Snyder Stephen , Taylor E. J.
Published: February 2020

Redox flow batteries are among the most promising electrical storage technologies for distributed energy storage and load leveling applications. Traditional redox flow batteries have the structure shown in Figure 1a, using the example of the iron redox couple. The bipolar plate is separated from the membrane using a felt electrode (on the Fe2+/Fe3+ redox side) and a plastic separator (on the Fe2+/Fe0 side). These electrodes have the following disadvantages:

Lower battery performance by

Creating undesirable pressure drops, and

Decreasing reactant mass transfer

Increased manufacturing costs due to

Difficulty in alignment during manufacturing,

Additional material (felt) cost.

To overcome these challenges, a pulse through mask electroetching process is being developed for fabrication of bipolar plates with novel engineered structures for redox flow batteries (RFBs). These engineered electrode/bipolar plate structures, which utilize arrays of posts, pyramids and/or pillars as well as flow fields and other structures on the bipolar plate surface to create uniform standoff between the plate and the membrane, may replace conventional bipolar plate components and eliminate the separate non-uniform carbon felt electrodes, as shown in Figure 1b. These engineered structures can be optimized with regard to gap, size and distribution, so as to obtain the desired electrolyte velocity while minimizing pressure loss and maximizing mass transfer. Furthermore, the surface textures of the structures can be engineered (roughened) to provide high surface area, for uniform iron deposition and for enhancing redox electron transfer kinetics. These modifications are being investigated with the intentions of promoting:

Improved battery performance by increased reactant mass transfer while maintaining acceptable pressure drop,

Reduced electrode cost (currently ~39% of total cell stack cost) by using thin metal substrates with engineered surfaces,

Simplified cell manufacturing costs (currently ~10% of total cell stack cost) by reducing the parts count and integrating the electrode and bipolar plate components, and

Enhancement in stack reproducibility by eliminating non-uniform felt type electrodes and maintaining a fixed membrane-plate separation.