Browse Topic: Electrolytes

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Development and Validation of a Reduced Order Model Incorporating a Semi-Empirical Degradation Model for Pouch Type LiFePO 4 /Graphite Cells2017-01-121804/23/2025
We propose a reduced order model (ROM) for LFP/graphite cells derived from the electrochemical thermal principles that considers degradation effects and validated against experimental data obtained from a large format pouch type LFP/graphite cell whose nominal capacity is 20Ah. The characteristics of the two-phase transition and path dependence were taken into account in the ROM using a shrinking-core model with a moving interface that presents lithium rich and deficient phase. Different currents (0.1/1/3/4C) were applied to fresh cells at different ambient temperatures (25/35/45°C). Comparison between simulated results of the ROM and the collected experimental data shows a good match. The path dependence was also analyzed experimentally. For degradation model, side reaction is treated as the predominant cause of degradation of cells, which are affected by the operating conditions, such as temperature and SOC cycling range. At every 30 or 40 cycles, the capacity and impedance of five
ZHAO, XINCHEN, Bi, Yalan, Choe, Song-Yul
Crafting Safe, Long-Cyclable Lithium Metal Batteries for High TemperaturesTBMG-5213912/01/2024
Existing commercial battery technologies, which use liquid electrolytes and carbonaceous anodes, have certain drawbacks such as safety concerns, limited lifespan, and inadequate power density particularly at high temperatures. This has prompted researchers to search for solid electrolytes that are safe and compatible with lithium metal anodes, which are known for their high theoretical specific power capacity.
Investigating the Effect of Water and Oxygen Distributions on Consistency of Current Density Using a Quasi-Three-Dimensional Model of a PEM Fuel Cell2021-01-073704/06/2021
Activation loss, mass transfer loss and ohmic loss are the three main voltage losses of the polymer electrolyte membrane fuel cell. While the former two types are relevant to concentration of oxygen in catalyst layer and the later one is associated with the water content in membrane. Distributions of water content and oxygen in a single cell are inconsistent which cause that current densities in each segment of the single cell are different. For the dry inlet gas, the water in the segments near the gas inlet channel will be carried to the segments near the gas outlet channel, which causes high ohmic loss of the segments near the gas inlet channel. In this work, a transfer non-isothermal quasi-three-dimensional model is developed to investigate inconsistency of current densities. Comprehensive physical and chemical phenomena inside the cell are included, especially the mass transfer of hydrogen, oxygen, vapor and liquid water in gas channels, gas diffusion layer and catalyst layer and
Wang, Xuhui, Lu, Yikang, Zhang, Baitao, Xu, Sichuan
Battery Thermal Management Simulation - 1D+1D Electrochemical Battery and 3D Module Modeling on Vehicle System Level2021-01-075704/06/2021
Approaching engineering limits for the thermal design of battery modules requires virtual prototyping and appropriate models with respect to physical depth and computational effort. A multi-scale and multi-domain model describes the electrochemical behavior of a single battery unit cell in 1D+1D at the level of intra-cell phenomena, and it applies a 3D thermal model at module level. Both models are connected within a common vehicle simulation platform. The models are discussed with special emphasis on battery degradation such as solid electrolyte interphase layer formation, decomposition and lithium plating. The performance of the electrochemical model is assessed by discharge cycles and repeated charge/discharge simulations. The thermal module model is compared to CFD reference data and studied with respect to its grid sensitivity. The temperature evolution of a module is simulated for enabled and disabled degradation equations revealing a very high impact of the degradation equations
Wurzenberger, Johann C., Jelovic, Mario, Šimundić, Mate, Mele, Igor, Katrasnik, Tomaz
Computational Design of Cathode Coating Materials for All-Solid-State Lithium-Ion Batteries2021-01-075804/06/2021
All-solid-state lithium (Li)-ion batteries have attracted significant interest for their enhanced energy density compared with conventional batteries employing an organic liquid electrolyte. However, the interfacial impedance and reaction between electrodes and the electrolyte can hinder the transport of Li-ions, thus degrading the battery performance. This paper presents a systematic screening method to identify coatings to reduce impedance and maintain interface stability during battery operation. Promising coating materials are rapidly selected by evaluating properties for ideal coating materials from computational databases containing a vast collection of Li compounds. Finally, a few candidates are discovered and their battery performances are tested. This approach is demonstrated to be an efficient way to predict and evaluate functional coatings for a high performance all-solid -state battery design.
Aoyagi, Koutarou, Wang, Chuhong, Matsuyama, Takuya, Mueller, Tim, Yoshida, Jun
‘Laxatives’ may ease challenge of lithium-ion alternative20AUTP02_1001/01/2020
The R&D dimension of the automotive industry often reveals novel solutions and cross-linking between materials, but a team of international scientists has come up with something truly unusual: boosting supercapacitor power and efficiency using newly developed “laxatives.” It's all about developing improved electrolytes as part of a program to enhance supercapacitor performance, making them more practical with enhanced energy storage for use in hybrid and electric vehicles (EVs). To do this, the team designed a new class of detergents involving the use of self-assembled nanostructures in detergent-like ionic liquids (IL), to facilitate improved charge storage at electrified interfaces. These detergents are chemically similar to human laxatives, said Dr. Gavin Hazell, a chemistry lecturer at the University of Chester's Faculty of Science and Engineering, and a member of the international team: “A discovery of this kind utilizes scientists from across the globe. We have a very diverse set
Birch, Stuart
Products of Tomorrow: September 2019TBMG-3512309/01/2019
Hybrid Cathodes Could Boost Energy Capacity of Lithium BatteriesTBMG-3492608/01/2019
Today's lithium-ion batteries use cathodes (one of the two electrodes in a battery) made of a transition metal oxide. Batteries with cathodes made of sulfur are considered a promising alternative to reduce weight. Designers of lithium-sulfur batteries face a tradeoff. The cathodes of such batteries are usually made in one of two ways: intercalation or conversion. Intercalation types — which use compounds such as lithium cobalt oxide — provide a high volumetric energy density, packing a lot of punch per volume because of their high densities. These cathodes can maintain their structure and dimensions while incorporating lithium atoms into their crystalline structure.
Mechanical Behavior of Representative Volume Element Specimens of Lithium-Ion Battery Modules without and with Electrolyte under Quasi-Static and Dynamic In-Plane Compressive Loading Conditions05-12-03-001407/02/2019
Abstract Small rectangular representative volume element (RVE) specimens of lithium-ion battery modules without and with electrolyte were tested under quasi-static and dynamic in-plane constrained compressive loading conditions. Effects of electrolyte and loading rate on the compressive behavior of RVE specimens were examined. The test results show that the average buckling stress of the specimens with electrolyte is higher than that of the specimens without electrolyte under both quasi-static and dynamic loading conditions. The test results also show that the average buckling stress of the specimens under dynamic loading conditions is higher than that of the specimens under quasi-static loading conditions, without or with the presence of electrolyte in the specimens. The percentage of increase of the average buckling stress of the specimens due to electrolyte under dynamic loading conditions is more than that of the specimens under quasi-static loading conditions. The percentage of
Kim, Eui Seop, Sung, Shin-Jang, Hong, Sung-Tae, Pan, Jwo
Graphene Coating Takes Oxygen Out of Lithium Battery FiresTBMG-3460106/01/2019
Lithium batteries allow electric vehicles to travel several hundred miles on one charge. Their capacity for energy storage is well known — so is their tendency to occasionally catch on fire. This “thermal runaway” occurs most frequently when the batteries overheat or cycle rapidly.
Wood-Based Technology Creates Electricity from HeatTBMG-3460806/01/2019
Researchers have transformed a piece of wood into a flexible membrane that generates energy from the same type of electric current (ions) on which the human body runs. This energy is generated using charged channel walls and other unique properties of the wood’s natural nanostructures. With this new wood-based technology, a small temperature differential can be used to efficiently generate ionic voltage.
Battery Electrolyte Doubles Driving Range for Electric VehiclesTBMG-3461006/01/2019
Conventional electrolytes used in lithium-ion batteries that power household electronics like computers and cellphones are not suitable for lithium-metal batteries. Lithium-metal batteries that replace a graphite electrode with a lithium electrode are the holy grail of energy storage systems because lithium has a greater storage capacity and, therefore, a lithium-metal battery has double or triple the storage capacity. That extra power enables electric vehicles to drive more than two times longer between charges.
Electric double layer capacitors prepared with polyvinyl alcohol and multi-walled carbon nanotubes2018-36-031309/03/2018
Portable electronics, wearables, electric vehicles and solar cells are sectors in increasingly development which include innovation and miniaturization of the devices. In this scenario, the development of smaller and lightweight energy storage devices, which store more energy, is required. Besides, it is desirable for these devices to be environmentally friendly to minimize pollution. In an attempt to meet these requirements, this work purposes the development and the characterization of nanofibers-based electrode composed of Polyvinyl alcohol (PVA) and multi-walled carbon nanotubes (MWCNT) for electric double layer capacitors (ELCDs) devices with aqueous electrolyte. This composite has been prepared by electrospinning technique and consolidate an electrical conductive and high-surface material electrode. After that, the PVA/MWCNT electrode was assembled in coin cell device with Sodium Sulfate (Na2SO4) electrolyte for electrochemical characterization. The characterization results
Real, Carla Giselle Martins, Vicentini, Rafael, Nunes, Willian Gonçalves, Boas, Otávio Vilas, Costa, Lenon Henrique, Soares, Davi Marcelo, Zanin, Hudson
Aluminum Electroplating Using Bromide SaltsTBMG-2831402/01/2018
Corrosion of structural materials is a serious problem for industrial and civil infrastructure worldwide, costing billions of dollars, and hampering gross domestic product. Corrosion also presents a threat to the environment and public safety, with highways and bridges losing structural integrity, and hazardous materials leaching into soils, waterways, and aquifers.
Process Turns Carbon Dioxide into 3D Graphene with Microporous SurfaceTBMG-2815601/01/2018
The conversion of carbon dioxide to useful materials usually requires high energy input due to its ultrahigh stability. A heat-releasing reaction between carbon dioxide and sodium was developed to take carbon dioxide and turn it into 3D graphene with micropores across its surface.
Nanoporous Material Reduces Computer Energy ConsumptionTBMG-2816401/01/2018
In order to store information in the conventional magnetic memories of electronic devices, the material’s small magnetic domains are oriented “up” or “down” by using externally applied magnetic fields. To generate these fields, it is necessary to produce electric currents; however, these currents heat up materials, and a large amount of energy is needed to cool them.
Sulfuric Acid Anodizing of Aluminum and Aluminum AlloysAMS03_25A (Current)10/04/2017
This SAE Standard specifies the properties of sulphuric acid anodizing of aluminum and aluminum alloys.
AMS B Finishes Processes and Fluids Committee
Magnesium Alloys, Anodic Treatment ofAMSM45202B (Current)09/20/2017
This specification covers the requirements for equipment, materials and procedures to be used in anodic treatments for magnesium base alloys for the purpose of increasing their corrosion resistance or producing surfaces suitable for the application of a protective organic finish.
AMS B Finishes Processes and Fluids Committee
Faster, Better, Economic - Newest Acid Zinc-Nickel Technology for Brake Caliper Plating2017-01-250709/17/2017
The demand for zinc-nickel coatings continuously increases in the automotive industry due to their high corrosion protection as well as superior wear and heat resistance compared to pure zinc platings. The state-of-the-art plating systems in the brake caliper industry are acid zinc-nickel electrolytes, as only they allow for direct plating on cast iron. Cast iron is the most common base material for the production of automotive brake components due to excellent mechanical and thermal properties. Well suited coatings will preserve the functional properties and provide additional advantages like improved corrosion protection and homogeneous and long lasting appearance. Consistently increasing quality demands, extended warranty periods and cost pressure lead to further developments and force the industry to look for new solutions. Therefore improvement of throwing power (thickness distribution) of acid zinc-nickel electrolytes would allow for a reduction in plating time and thus an
Hoch, Matthias, Kaczmarek, Michal, Ahr, Markus
Safer, Cleaner, Corrosion-Protecting Metal CoatingsTBMG-2720007/01/2017
LumiShield Pittsburgh, PA For more info click
High Power Cell for Mild and Strong Hybrid Applications Including Chevrolet Malibu2017-01-120003/28/2017
Electric vehicles have a strong potential to reduce a continued dependence on fossil fuels and help the environment by reducing pollution. Despite the desirable advantage, the introduction of electrified vehicles into the market place continues to be a challenge due to cost, safety, and life of the batteries. General Motors continues to bring vehicles to market with varying level of hybrid functionality. Since the introduction of Li-ion batteries by Sony Corporation in 1991 for the consumer market, significant progress has been made over the past 25 years. Due to market pull for consumer electronic products, power and energy densities have significantly increased, while costs have dropped. As a result, Li-ion batteries have become the technology of choice for automotive applications considering space and mass is very critical for the vehicles. Although there is not one definition for mild and strong hybrid, for the purpose of GM applications, mild hybrid systems have a nominal voltage
Saharan, Vijay, Nakai, Kenji
The Pre-Treatment and Protection of Steel Items of Specified Maximum Tensile Strength Exceeding 1450 MPaAMS03_4A (Current)03/21/2017
This SAE Standard specifies the special treatments and precautions that are to be observed when protective and other surface treatments are applied to items, including springs, made from steel of specified maximum tensile strength exceeding 1450 MPa. The requirements of this Standard qualify those in process specifications and override the latter where there is conflict. The Standard also gives advice on design, manufacture, and preparation of items prior to cleaning and protection.
AMS B Finishes Processes and Fluids Committee
Advanced Finishes for Brake Components and Other Castings2016-01-195109/18/2016
Caused by a number of beneficial properties inherently from the zinc-nickel material, this electrodeposited alloy is used more and more for cathodically protecting layers on ferrous components like cast iron brake calipers. Direct plating from acidic solutions is the state-of-the-art solution for zinc-nickel surface finishing of these components. To contribute to the continuous improvement of the final component and reduce the finishing cost, areas for improvement have been scrutinized in a current finishing system. Areas for improvement have been identified in the uniformity of the nickel distribution within different current densities and in the handling and economy of the metallic zinc anodes used for zinc metal replenishment. While today’s acidic zinc-nickel electrolytes suit and usually exceed the requirements for an alloy containing 10-15% nickel, nickel incorporation may drop just below 12% incorporation rate in areas which are plated at high current densities. Formation of
Dingwerth, Björn
Lithium Fluoride as a Polysulfide Shuttle Inhibitor for Lithium Sulfur ChemistryTBMG-2219906/01/2015
Lyndon B. Johnson Space Center, Houston, Texas
Sulfuric Acid Anodizing of Aluminum and Aluminum AlloysAMS03_25 (Historical)05/21/2015
This SAE Standard specifies the properties of sulphuric acid anodizing of aluminum and aluminum alloys.
AMS B Finishes Processes and Fluids Committee
Methods for Determining Plastic Deformation in Sheet Metal StampingsJ863_201504 (Current)04/28/2015
This SAE Recommended Practice describes methods for determining plastic deformation encountered in the forming or drawing of sheet steel.
Metals Technical Committee
The Pre-Treatment and Protection of Steel Items of Specified Maximum Tensile Strength Exceeding 1450 MPaAMS03_4 (Historical)04/27/2015
This SAE Standard specifies the special treatments and precautions that are to be observed when protective and other surface treatments are applied to items, including springs, made from steel of specified maximum tensile strength exceeding 1450 MPa. The requirements of this Standard qualify those in process specifications and override the latter where there is conflict. The Standard also gives advice on design, manufacture, and preparation of items prior to cleaning and protection.
AMS B Finishes Processes and Fluids Committee
Degradation Analysis of Pouch Cell Using High-Energy Cathode Material for Advanced Lithium-ion Battery2015-01-119304/14/2015
Lithium-rich layered oxide, expressed as xLi2MnO3-(1-x) LiMO2 (M = Ni, Co, Mn, etc.), exhibits a high discharge capacity of 200 mAh/g or more and a high discharge voltage at a charge of 4.5 V or more. Some existing reports on cathode materials state that lithium-rich layered oxide is currently the most promising candidate as an active material for high-energy-density lithium-ion cells, but there are few reports on the degradation mechanism. Therefore, this study created a prototype cell using a lithium-rich layered cathode and a graphite anode, and analyzed the degradation mechanism due to charge and discharge. In order to investigate the causes of degradation, changes in the bulk structure and surface structure of the active material were analyzed using high-resolution X-ray diffraction (HRXRD), a transmission electron microscope (TEM), X-ray absorption fine structure (XAFS), and scanning electron microscope/energy dispersive X-ray spectroscopy (SEM-EDX). The results showed that
Maeyama, Hiroto, Sukigara, Toru
Electrochemically Powered Vehicles: Current Possibilities and Investigation of the Li-O2 Electrochemical Reaction on Catalyst Surfaces: Implications for a Metal-Air Battery2015-01-117904/14/2015
Significant research has been underway for many years to develop technologies to electrochemically power vehicles with limited success. Unfortunately, most technologies fail to achieve theoretical performance and/or are prohibitively too expensive for mass marketed vehicles. Most of the issues with electrochemical technologies can ultimately be attributed to materials issues, whether it is cost, durability, or activity. A broad examination of potential electrochemical technologies is provided identifying key materials issues with each. Included are the results of recent research involving lithium-oxygen batteries. The observations from this research have identified the electrochemical product, lithium peroxide, and its properties to be the most pressing material issue for lithium-oxygen battery. A future research vision is proposed counter to the current research trend of electrocatalyst/electrolyte development. The focus will be to understand the formation of lithium peroxide and
Brooks, Christopher J., Kreidler, Eric
Zinc Coated Press-Hardening Steel - Challenges and Solutions2015-01-056504/14/2015
Press-hardening steels get more and more popular for body in white applications as an approach to meet the demands of passenger safety and CO2 reduction. Unlike the larger part of the structure that is typically zinc coated, the majority of the PHS parts is either uncoated or aluminum silicon coated. This paper shall give an overview of press-hardening steels with zinc coatings with detailed results for corrosion resistance, weldability and mechanical properties for strength levels of 490 to 1800 MPa. Furthermore as for zinc coated material maintaining a robust press-hardening process is of even higher importance than for uncoated or AlSi coated material. A range of different processes including indirect and direct process are shown in detail. Especially the topic of micro-cracks, mechanisms and avoidance of micro-cracks in the direct process will be discussed. Results from industrial and semi industrial production are shown.
Kurz, Thomas, Luckeneder, Gerald, Manzenreiter, Thomas, Schwinghammer, Harald, Sommer, Andreas
Wearable Electrolyte Sensor Provides Instant ReadingsTBMG-2007707/01/2014
Electrolytes, such as potassium, calcium, magnesium, and other salts are essential in carrying nerve impulses that tell the heart and other muscles when to contract or relax. A proper balance of them in the human body is required for the normal function of cells and organs. Realizing that laboratory analyses can be expensive, and that patients, athletes, and soldiers would prefer a pain-free, wrist-worn diagnostic device that can analyze, continuously record, and even remedy low electrolyte levels, researchers at Sandia National Laboratories, Albuquerque, NM, have developed and are patenting a prototype model that can analyze various electrolyte levels on the spot, yet fit in a palm or be worn on a wrist. The device, when commercially available, could decrease the time users would spend in emergency rooms, lab testing facilities, or doctors’ offices.
Improved Cyclic Performances of Li-Sulfur Batteries with Sulfone-Based Electrolyte2014-01-184404/01/2014
The effects of electrolyte on the cyclability of Li/S battery were investigated in this work. The electrochemical properties of single component ether solvents and a binary mixture of ether solvents were studied. These ether-based electrolytes have polysulfide shuttle problems which result in severe low Coulombic efficiency. To overcome these issues, sulfone-based solvent which forms a stable passivation film at the anode surface were used. As a result, the proper composition of sulfone-based electrolyte were obtained. Its capacity and reversible capacity retention were improved to 715 mAh/g and 72.6% which were increased by 52.1% and 63.1%, respectively, compared to those of ether-based electrolyte.
Shin, Nary, Ryu, Kyoung Han, Kim, Yong-Gu, Lee, Ho-Taek
Outside-Engine Wear Study of Ceramic Coated Cylinder Wall Tribo-System2014-01-095804/01/2014
This research focuses on study of feasibility of using ceramic oxide coatings on the cylinder wall of hypoeutectic aluminum silicon alloy engine blocks. Coatings are achieved in an aqueous electrolytic bath and composed of both alpha and gamma phases of Al2O3 and have shown promising wear resistance. Composition and acidity level of the electrolyte creates a variation of surface roughness, coating hardness and thickness which has direct influence on the wear behavior of the sliding surfaces. The effect of load bearing and coating morphology on coefficient of friction was studied. SEM images of the substrate showed no predominant wear behavior or delamination. Coefficient of friction and wear rate were also measured. This study shows the importance of surface structure on oil retention and wear rate. Coarser coatings can be desirable under starved oil condition since they show lower coefficient of friction. This can be explained due to the oil retention structure of coarse coatings with
Eiliat, Hoda, Nie, Xueyuan, Tjong, Jimi, Villafuerte, Julio
Li-Ion Electrolytes Containing Flame-Retardant AdditivesTBMG-2342102/01/2014
In order to improve the safety and performance of lithium- ion cells, especially over a wide operating temperature range, a number of Li-ion electrolytes have been developed that contain flame-retardant additives in conjunction with fluorinated co-solvents to provide a safe, wide-operating-temperature- range system. Previously, fluorinated esters were incorporated into multi-component electrolyte formulations and their performances have been demonstrated over a wide temperature range (–60 to +60 °C). The fluorinated esters co-solvents were employed due to their favorable properties and improved safety characteristics, mainly associated with their low flammability associated with their halogenated nature.
Canada Motor Vehicle Safety Standard - CMVSS 305 - Electrolyte Spillage and Electrical Shock Protection.INT-REG-55001/16/2014
Electrolyte Spillage and Electrical Shock Protection.
Aluminum Anodizing Technology for Reusable Medical EquipmentTBMG-1875712/01/2013
Aluminum outperforms other materials to become an ideal choice for manufacturing of medical instruments, equipment, and devices mainly due to its intrinsic sustainable qualities. It is recyclable, lightweight, strong, non-toxic, inexpensive, easily machined and accepts many types of finishes. Metal integrity is crucial for medical devices that must hold tight tolerances and handle harsh conditions of cleaning and sterilization to perform their desired tasks. Medical coatings such as anodizing are used in many applications in the medical industry, including medical cases, trays, instruments, and general hospital accessories and devices made out of aluminum.
Multi-Physics Numerical Analysis of PEMFC for Automobile Application2013-01-047604/08/2013
Polymer Electrolyte Membrane Fuel Cell (PEMFC) is regarded as a potential alternative clean energy source for automobile applications. Key challenges to the acceptance of PEMFC for automobiles are the cost reduction, improvement in power density for its compactness, and cold-start capability. High current density operation is a promising solution for them. However, high current density operation under normal and sub-zero temperature requires more oxygen flux for the electrochemical reaction in the catalyst layer, and it causes more heat and water flux, resulting in the significant voltage losses. So, the theoretical investigation is very helpful for the fundamental understanding of complex transport phenomena in high current density operation under normal and sub-zero temperature. In this study, the numerical model was established to elucidate the impacts of mass transport phenomena on the cell performance through the numerical validation with experimental and visualization results
Tabuchi, Yuichiro, Kotaka, Toshikazu, Wang, Chao-Yang
Electrochemical Energy Storage MaterialsTBMG-1568702/01/2013
One of the most important requirements in next-generation batteries is to concurrently deliver high energy density and high power density (fast charge-discharge rates). The high power density requirement can be met with enhanced ion and electron transport kinetics in batteries, which in turn requires active materials with high ion diffusion constants and conductive additives or architectures for faster electron transport to respective current collectors. It is well known that nanostructuring the electrode materials would significantly enhance the characteristic time constant for ion diffusion, thereby reducing the intercalation/deintercalation time.
High Performance Corrosion Protection for Brake Components: Direct Zinc-Nickel Application and Post-Treatment2012-01-183109/17/2012
Cast-iron is a well suited material for manufacturing automotive brake components due to excellent mechanical and thermic properties. The application of a well chosen cathodically protecting coating adds durable appearance and preservation of the functional properties of the components. The selection of the right coating is driven by multiple factors of which economic considerations will always rank within the highest priorities next to protection performance and the appearance of the coating. Aiming for the highest possible performance in cathodic corrosion protection coatings leads directly to zinc-nickel coatings. Zinc-nickel coatings are already state-of-the-art in the finishing of mild steel and carburized steel materials in the automotive industry, mostly being plated from alkaline plating solutions. The application of alkaline solutions to cast iron material is not feasible under industrial conditions at an acceptable reject rate due the electrochemical properties of the cast
Dingwerth, Bjoern O.
Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell MembranesTBMG-1423208/01/2012
Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrenebased quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells.
France - Addition of 13 Substances to the Candidate List of SVHC under REACHRS-BNA-AUG_12_1707/14/2012
The Ministry of the Environment has issued notice announcing the addition of 13 substances to the candidate list of substances of very high concern (SVHC) under REACH. Companies that produce or import articles containing one of the substances in a concentration above 0.1 percent weight by weight (w/w) must provide information to consumers. Companies that produce or import such articles in quantities above 1 metric ton per year must also notify the European Chemicals Agency (ECHA) before Dec. 18, 2012. The candidate list includes EGDME (CAS 110-71-4), use as an electrolyte solvent in lithium batteries. The notice was issued July 14, 2012.
Asymmetric Supercapacitor for Long-Duration Power StorageTBMG-1408007/01/2012
A document discusses a project in which a series of novel hybrid positive electrode materials was developed and tested in asymmetric capacitors with carbon negative electrodes. The electrochemical performance of the hybrid capacitors was characterized by cyclic voltammetry and a DC charge/discharge test. The hybrid capacitor exhibited ideal capacitor behavior with an extended operating voltage of 1.6 V in aqueous electrolyte, and energy density higher than activated carbon-based supercapacitors.
Three-Dimensional Porous Particles Composed of Curved, Two-Dimensional, Nano-Sized Layers for Li-Ion BatteriesTBMG-1388506/01/2012
Building on previous knowledge acquired through research on thin-film batteries, three-dimensional (3D) porous macroscopic particles consisting of curved two-dimensional (2D) nano-structures of Si may bring unique advantages for Si anode technology. Prior work on thin Si films showed that during Li insertion, large-area Si films mostly accommodate the volume changes via variation in thickness. Therefore, the changes in the external surface area can fundamentally be minimized and thus, formation of a stable, solid electrolyte interphase (SEI) should be easier to achieve. In contrast, Si nanoparticles expand uniformly in all dimensions and thus, their outer surface area (where SEI forms) changes dramatically during insertion/extraction of Si. The low elasticity of the SEI makes it difficult to achieve the long-term stability under cycling load. Further, thin Si films have lower surface area (for the same mass), in comparison to Si nanoparticles, and better potential for achieving low
Electrochemical Ultracapacitors Using Graphitic NanostacksTBMG-1357105/01/2012
Electrochemical ultracapacitors (ECs) have been developed using graphitic nanostacks as the electrode material. The advantages of this technology will be the reduction of device size due to superior power densities and relative powers compared to traditional activated carbon electrodes. External testing showed that these materials display reduced discharge response times compared to state-of-the-art materials. Such applications are advantageous for pulsed power applications such as burst communications (satellites, cell phones), electromechanical actuators, and battery load leveling in electric vehicles. These carbon nanostructures are highly conductive and offer an ordered mesopore network. These attributes will provide more complete electrolyte wetting, and faster release of stored charge compared to activated carbon.
Geometry-Resolved Electro-Chemistry Model of Li-Ion Batteries2012-01-066304/16/2012
The paper presents a simulation approach to Li-Ion batteries based on geometrically resolved electrodes. This means that solid particles and the space occupied by electrolyte are not overlapping but are represented by contiguous, arbitrarily shaped volumes. The solid-electrolyte interface is explicitly resolved and thus allows detailed modeling of electro-chemical processes that are essential for studying performance of the battery cell. Finite volume method is used to solve the equations governing the mass and thermal energy conservation in solid and electrolyte, as well as the distribution of electric potential. The solution domain is discretized in contiguous control volumes of arbitrary polyhedral shape, with conformal interface between solid and fluid regions. Butler-Volmer equation is used to describe the kinetics of solid-electrolyte interface. For the time being, representative geometries of electrodes are manufactured using CAD-tools, but real geometries obtained using
Spotnitz, Robert, Kaludercic, Boris, Muzaferija, Samir, Peric, Milovan, Damblanc, Gaetan, Hartridge, Steve
Better Proton-Conducting Polymers for Fuel-Cell MembranesTBMG-1264601/01/2012
Polyoxyphenylene triazole sulfonic acid has been proposed as a basis for development of improved proton-conducting polymeric materials for solidelectrolyte membranes in hydrogen/air fuel cells. Heretofore, the proton-conducting membrane materials of choice have been exemplified by a family of perfluorosulfonic acid-based polymers (Nafion7 or equivalent). These materials are suitable for operation in the temperature of 75 to 85 °C, but in order to reduce the sizes and/or increase the energy-conversion efficiencies of fuelcell systems, it would be desirable to increase temperatures to as high as 120 °C for transportation applications, and to as high as 180 °C for stationary applications. However, at 120 °C and at relative humidity values below 50 percent, the loss of water from perfluorosulfonic acid-based polymer membranes results in fuel-cell power densities too low to be of practical value. Therefore, membrane electrolyte materials that have usefully high proton conductivity in the
Handheld Universal Diagnostic SensorTBMG-1261101/01/2012
The rHEALTH technology is designed to shrink an entire hospital testing laboratory onto a handheld device. A physician or healthcare provider performs the test by collecting a fingerstick of blood from a patient. The tiny volume of blood is inserted into the rHEALTH device (see figure). Inside the device is a microfluidic chip that contains small channels about the width of a human hair. These channels help move the blood and analyze the blood sample. The rHEALTH sensor uses proprietary reagents called nanostrips, which are nanoscale test strips that enable the clinical assays. The readout is performed by laser-induced fluorescence. Overall, the time from blood collection through analysis is less than a minute.
New Energy Source Powers Single-Use Mil/Aero EquipmentTBMG-1226212/01/2011
Until recently, single-use high energy devices were typically powered by reserve/thermal batteries using decades-old technology. Recognizing that battery performance limitations could hinder new product development, the U.S. DoD identified a “critical need” for a new generation of high-power, long life batteries.
Canadian Motor Vehicle Safety Standard - CMVSS 305 - Electrolyte Spillage and Electrical Shock Protection.INT-REG-14911/22/2011
Electrolyte Spillage and Electrical Shock Protection.
Magnesium Alloys, Anodic Treatment ofAMSM45202A (Historical)11/21/2011
This specification covers the requirements for equipment, materials and procedures to be used in anodic treatments for magnesium base alloys for the purpose of increasing their corrosion resistance or producing surfaces suitable for the application of a protective organic finish.
AMS B Finishes Processes and Fluids Committee
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