bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nr Measurements to Study The Reversible Transfer of Lithium Ion in Lithium Titanium Oxide
Authors: Esaka T. , Takai S. , Kamata M. 
Published: April 2011

ABSTRACTUsing Neutron Radiography (NR), the transfer of lithium ions has been investigated in the high temperature-type lithium ion conductor, Li1.33Ti1.67O4. After supplying direct current to the oxides with different isotope ratios (6Li/7Li), NR images were obtained, which confirmed lithium ion movement in the oxides as changes of bright parts on negative films. Analysis of the NR images clarified that lithium ions in the spinel-type Li1.33Ti1.67O4were transported almost reversibly according to the polarity of electric field applied. The relations between the lithium contents in the samples and the film gray level showed that the cathode region in the charged sample contains about twice more lithium than in the original sample. Furthermore, NR method was applied to check lithium ion insertion into the TiO2(rutile) sample. As a result, an informative Neutron Radiogram showing the lithium ion insertion was obtained.
Vibrational Spectroscopic Studies of the Local Environment in 4-Volt Cathode Materials
Authors: Julien C. , Massot M. , Perez-Vicente C. , Haro-Poniatowski E. , Nazri G. A. , Rougier A. 
Published: April 2011

ABSTRACTWe report the vibrational spectra of numerous 4-volt cathode materials, the transition metal oxides which are potential materials for advanced Li-ion batteries. They provide high specific energy density, high voltage, and remarkable reversibility for lithium intercalation-deintercalation process. Studied were carried out by Raman and FTIR spectroscopies. Oxides such as LiMn2O4, LiNiVO4, LiCoVO4 spinels, LiMeO2 (Me=Co, Ni, Cr) layered compounds and their mixed compounds have been investigated. The local environment of cations against oxygen neighboring atoms has been determined by considering tetrahedral and octahedral units building the lattice. Structural modifications induced by the intercalation-deintercalation process, by the cation substitution, or by the low-temperature preparation route are also examined. The results are compared with those of end members.
Influence of Carbon Structure and Physical Properties on The Corrosion Behavior in Carbon Based Air Electrodes for Zinc Air Batteries
Authors: Golovin M. Neal , Kuznetsov Irena , Atijosan Iyi , Tinker Lawrence A. , Pedicini Christopher S. 
Published: April 2011

Rechargeable zinc-air batteries are a long run time solution for portable electronics. Cells with a nominal voltage of 1.05 V have a specific energy of 169 Wh kg−1 and aenergy density of 219 Wh L1. This cell is capable of delivering 16 – 18 Ah of capacity at 2 A (16.7 mA cm−2) discharge rate. However, the cycle life of these cells is artificially shortened because of the generation of carbon dioxide in the alkaline electrolyte during the cycling of the cell. The carbon dioxide has the effect of removing the OH− (equation 1) needed by the anodehalf reaction (equations 2 and 3). The need for hydroxide is demonstrated in equation 2.There is literature evidence [1,2] that the CO2 was the result of corrosion of the carbon matrix of the air electrode. We report here the results of our investigation of this corrosion reaction and what properties of the carbon contribute to the corrosion reaction rate.
Application to Lithium Batteries of Ternary Solvent Electrolytes with Ethylene Carbonate – 1,2-Dimethoxyethane Mixture
Authors: Sasaki Y. , Yamazaki N. , Handa M. 
Published: April 2011

ABSTRACTThe electrolytic conductivity, the lithium cycling efficiency of lithium electrode and the energy density for Li/V2O5(2025) coin-type cell were examined in ternary solvent electrolytes containing LiPF6and LiClO4with ethylene carbonate(EC) – 1,2-dimethoxyethane(DME) equimolar binary mixture at 25°C. The solvents applied to EC – DME mixture are dimethyl carbonate(DMC), ethyl methyl carbonate(EMC), diethyl carbonate(DEC), 1,3-dioxolane(DOL), 2,2-bis(trifluoromethyl)-1,3-dioxolane(TFMDOL), 1,3-dimethy1–2-imidazolidinone(DMI) and 1-methyl-2-pyrrolidinone(NMP). The order of decrease of the molar conductivities in ternary solvents electrolytes except DMI and NMP systems is agreement with that of increase in viscosities of the solvents applied to EC – DME binary mixture. The molar conductivities in ternary solvent electrolytes containing DMI and NMP are mainly affected by the dielectric constants rather than viscosities of mixed solvents. The energy density of Li/V2O5(2025) coin-type cell in LiPF6/EC – DME – DOL electrolyte with the highest molar conductivity was 500 Wh kg−1, which is the highest value in every ternary electrolyte. The lithium cycling efficiency(charge - discharge coulombic cycling efficiency of lithium electrode) in EC – DME – EMC, EC – DME – DMI and EC – DME – TFMDOL electrolytes containing LiPF6is more than 75% at 40 cycle numbers. The lithium electrodeposition on the Ni(working) electrode surface in ternary solvent electrolytes by cyclic voltammetry was observed by atomic force microscopy(AFM) and scanning electron microscope(SEM).
Polymer-Oxide Anode Materials
Authors: Kerr T. A. , Leroux F. , Nazar L. F. 
Published: April 2011

ABSTRACTThe adaptable layer structure of molybdenum trioxide was exploited to insert the amino derivative form of the conductive polymer poly(para-phenylene) (PPPNH2) within the van der Waals gap. Two polymer insertion routes were designed that yield novel PPPNH2-MoO3 materials of different composition. Characterization of these materials using powder XRD, thermal analysis, and FTIR spectroscopy shows insertion of the polymer has occurred. The properties of the nanocomposites for low potential electrochemical lithium insertion were compared to those of the sodium molybdenum bronze using the materials as cathodes in conventional lithium cells. Initial results indicate the specific charge capacity and irreversibility during the first charge are effected by polymer content whereas polarization is not.
Variation of Stresses Ahead of The Internal Cracks in ReNI5 Powders During Hydrogen Charging and Discharging Cycles
Authors: Biner S. B. 
Published: April 2011

ABSTRACTIn this study, the evolution of the stress-states ahead of the penny shaped internal cracks in both spherical and disk shaped ReNi5 particles during hydrogen charging and discharging cycles were investigated using coupled diffusion/deformation FEM analyses. The results indicate that large tensile stresses, on the order of 20–50% of the modulus of elasticity, develop in the particles. The disk shaped particles, in addition to having faster charging/discharging cycles, may offer better resistance to fracture than the spherical particles.
Comparison of Carbon and Metal Oxide Anode Materials for Rechargeable Li-Ion Cells
Authors: Huang C.-K. , Sakamoto J. S. , Smart M. C. , Surampudi S. , Wolfenstine J. 
Published: April 2011

ABSTRACTThe state of the art (SOA) Li-ion cells utilize carbon anodes. However, to improve specific energy, energy density, and safety of cells using carbon anodes, alternative anodes must be developed. Recently, Fuji Film Inc. has suggested the use of tin oxide based anodes in Li-ion cells. It is believed mat cells containing tin oxide based anodes have the potential to meet the need for NASA's future missions. As a result, we conducted an analysis to compare the performance of cells containing carbon anodes and cells containing tin oxide anodes. The comparison between these cells involved the following: 1) reaction mechanisms between Li and carbon and reaction mechanisms between Li and tin oxide, 2) half-cell and full-cell performance characteristics, 3) interactions between the anode materials and electrolyte types and compositions, and 4) the optimization of binder composition.
Electrochemical and Spectroscopie Evaluation of Lithium Intercalation in Tailored Polymethacrylonitrile Carbons
Authors: Zavadil Kevin R. , Guidotti Ronald A. , Even William R. 
Published: April 2011

AbstractDisordered polymethacrylonitrile (PMAN) carbon monoliths have been studied as potential tailored electrodes for lithium ion batteries. A combination of electrochemical and surface spectroscopie probes have been used to investigate irreversible loss mechanisms. Voltammetric measurements show that Li intercalates readily into the carbon at potentials IV positive of the reversible Li potential. The coulometric efficiency rises rapidly from 50% for the first potential cycle to greater than 85% for the third cycle, indicating that solvent decomposition is a self-limiting process. Surface film composition and thickness, as measured by x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS), does not vary substantially when compared to more ordered carbon surfaces. Li+ profiles are particularly useful in discriminating between the bound states of Li at the surface of solution permeable PMAN carbons.
Voltage Hysteresis and Heat Generation Behavior in Lithium-Ion Batteries
Authors: Saito Y. , Takano K. , Kanari K. , Nozaki K. 
Published: April 2011

ABSTRACTIn order to characterize the heat generation behavior of a lithium-ion cell during charge and discharge, calorimetry has been carried out. The influence of past treatments applied to the cell is examined based on heat generation. The test cell shows a voltage hysteresis during charge and discharge, and the heat generation behavior is related to this hysteresis. A hard carbon is used in the cell as the negative electrode material, and the hysteresis mechanism and heat generation are discussed based on the reactions in the hard carbon electrode.
Local Structure of Ball-Milled Carbons for Lithium Ion Batteries: A Pair Distribution Function Analysis
Authors: Claye A. , Zhou P. , Fischer J. E. , Disma F. , Tarascon J-M. 
Published: April 2011

ABSTRACTThe local atomic structure of ball-milled carbons was investigated by radial distribution function (RDF) analysis using pulsed time-of-flight neutron diffraction. The results exhibit a gradual loss of long-range order as a function of milling time. Modeling of the elastic structure factors and of the differential correlation functions identified the structure of ball-milled carbons as finite-size graphene fragments whose size decreases continuously with milling time. The large increase in lithium reversible capacity after 20 hours of milling was correlated with the loss of interlayer correlation between graphite flakes, similar to the structure of hard carbons in the “House of Cards” model.
Characteristics of Boron Doped Mesophase Pitch-Based Carbon Fibers as Anode Materials for Lithium Secondary Cells
Authors: Tamaki Toshio , Kawamura Toshifumi , Yamazaki Yoshinori 
Published: April 2011

AbstractMesophase pitch-based Carbon Fibers(MCF) have been investigated as anode materials for lithium secondary cells by examining their physical and electrochemical properties. Discharge capacity and initial charge-discharge efficiency of the materials were studied in relation to the heat treatment temperatures of MCF. MCF heat treated at about 3,000° C gave high discharge capacity over 310mAh/g, good efficiency (93 %) and superior current capability of 600mA/g (6mA/cm2). On the other hand, to improve the battery capacity, Boron was doped to the fiber about several % by adding B4C to the pre-carbonized milled fibers and then heat-treated up to 3000°C in Ar. Then heat treated at 2,500°C under vacuum condition to remove remained B 4 C. The structure of Boron-doped fibers was characterized and compared with that of non-doped standard fibers, and also Li ion battery performances are evaluated. The Boron-doped MCF indicated improvement in graphitization and increased discharge capacity as high as 360mAh/g. The voltammograms of both fibers are different from each other. The cell mechanism is discussed based on the unique structure of Boron-doping to the MCF is very effective for the battery performance.
High Surface Area Metal Carbide and Metal Nitride Electrodes
Authors: Wixom M. R. , Tarnowski D. J. , Parker J. M. , Lee J. Q. , Chen P.-L. , Song I. , Thompson L. T. 
Published: April 2011

ABSTRACTProcesses for fabricating new high surface area ceramic electrode materials have been developed. These electrode materials have been applied in electrochemical capacitors and related energy storage and conversion devices. Several synthetic approaches have been developed for producing high surface area carbide or nitride active materials. The fabrication methods provide the capability to vary the composition and microstructure of the electrode material. A number of new candidate high surface area electrode materials have been synthesized. Compositional and microstructural information is presented. Electrodes have been evaluated by cyclic voltammetry, chronopotentiometry, and impedance spectroscopy in acidic and basic aqueous electrolyte systems. Single electrode and single cell performance data are presented. Intrinsic properties such as open circuit potential, electrochemical stability and specific capacitance are discussed with respect to electrode composition. The influence on performance of extrinsic factors such as electrode thickness, particle size, and pore structure is also discussed. The performance of these new materials is compared to carbon, with emphasis on advantages with respect to volumetric energy and power density.
Electrical Properties of Integrated Ta2O5 Metal-Insulator-Metal Capacitors
Authors: Martin B. C. , Basceri C. , Streiffer S. K. , Kingon A. I. 
Published: April 2011

ABSTRACTWe demonstrate the feasibility of a Ta2O5-based metal-insulator-metal (MIM) capacitor module which is integrated into the backend-of-the-line of a 0.5 μm CMOS process flow. The demonstration utilizes 6-inch wafers, sputtered Ta2O5 films with TaN and TiN electrodes, reactive ion etch (RIE) processes for defining the capacitor stack, and a metallization scheme which uses hot Al(Cu) and W plugs and a standard forming gas anneal (N2-5% H2). Acceptable electrical properties have been achieved within these processing constraints for the integrated MIM capacitor module, including specific capacitance (C/A) and leakage current density (J) of ≥ 5 fF/μm2 and ≤ 1 pA/pF-V, respectively. In addition, we compare the fundamental properties of the Ta2O5 dielectric with literature reports and point out that leakage mechanisms must be analyzed with care due to significant dielectric relaxation in the films under certain processing/measurement conditions. For the baseline integrated films, we confirm that leakage is most consistent with a Poole-Frenkel mechanism.
Giant Magnetoimpedance: A Relevant Application of Impedance Spectroscopy
Authors: Garcia K. L. , Valenzuela R. 
Published: April 2011

ABSTRACTThe impedance response of amorphous ferromagnetic wires is measured in the 5 Hz-13 MHz frequency range by applying a small AC current of 1 mA (RMS). A DC magnetic field (in the 0–6.7 kA/m range) is simultaneously applied. The impedance response is analyzed by means of simple series and parallel equivalent circuits. An association of circuit elements and physical parameters of the sample is proposed.
Study of the Molecular Mobility of Polysaccharide Solid Thin Layers by Dielectric Relaxation Spectroscopy
Authors: Liedermann K. , Lapčík L. , Desmedt S. 
Published: April 2011

ABSTRACTTemperature dependence of measured dielectric relaxation spectra (DRS) in the frequency range 20 Hz - 1 MHz of hydroxyethylcellulose (HEC) are in the temperature range 100 – 350 K. of Arrhenius character with one relaxation process at 150 – 250 K. This process reflects most probably β-relaxation of the side chain groups. Calculated activation energy of this process was 5730 kJ/mole. Four types of polysaccharides were studied at 293 K temperature: hyaluronic acid (HA), chondroitin sulfate (CHS), HEC and carboxymethylcellulose (CMC), in the low-frequency range 10−5 - 100 Hz. Measured dielectric spectra were interpreted as sum of one A.C. conductivity process and of up to two relaxation processes. The relaxation processes were described by means of the Havriliak-Negami formula and their parameters were related to the molecular structure of the polymers. The low value of a in CHS is related to its strong coupling due to the presence of two polar groups in its monomeric unit, whereas low values of α × β are interpreted as being due to the strong steric hindrances caused by long pendants present in HEC.
Complex Dielectric Spectroscopy Characterization of a Li0.982Ta1.004O3 Ferroelectric Single Crystal
Authors: Dong Ming , Gerhardt Rosario A. 
Published: April 2011

ABSTRACTThe dielectric properties of a c-oriented ferroelectric Li0.982Ta1.004O3 single crystal have been investigated. The frequency and the temperature dependence of the dielectric properties have been measured from 500 to 650°C at frequencies ranging from 5 to 106 Hz. Both blocking and non-blocking electrodes were used for separating the electrode effect from the crystal bulk dielectric response. A low-frequency dispersion was identified to be due to the contribution of Li+ ionic carriers. Based on the electrical measurement data and complex nonlinear least squares fitting, an equivalent circuit is proposed to represent the dielectric properties of the single crystal.
Micromachined SFM Probes for High-Frequency Electric and Magnetic Fields
Authors: Van Der Weide D. W. , Agrawal V. , Neuzil P. , Bork T. 
Published: April 2011

ABSTRACTWe discuss micromachined localized high-frequency electric (coaxial) and magnetic (loop) field probes integrated with scanning force microscopes. Our approach enables simultaneous acquisition of both field and topography in the radio frequency (RF) through millimeter-wave regime, enabling more complete characterization of materials, devices and circuits.
The Use of Computer Simulations to Interpret and Understand Electrical Measurements
Authors: Garboczi Edward J. 
Published: April 2011

ABSTRACTIt is very rare to obtain complete 3-D information in the form of images of the microstructure of a material. Most often this information is incomplete because the resolution is inadequate, or is restricted to 2-D, via some kind of micrograph, or is not available at all. In the case of incomplete microstructural information, electrical measurements are then used to try to check a hypothesized microstructure, to see ifit can account for the measured electrical response. But even when complete microstructural information is available, if the microstructure is random, then it is not possible to analytically calculate the electrical response of the microstructure. The use of computer simulations, both to generate material shape and topology and numerically solve the electrical equations, is then required. Computer simulations allow the use of more complex hypotheses for the microstructure of a material, as the electrical response can be accurately computed for a wide range of microstructural shapes and topologies.
Electrochemical Corrosion of Electrodes in a Simulated Nuclear Waste Glass Melt
Authors: Sundaram S. K. 
Published: April 2011

ABSTRACTCorrosion of potential candidate electrode materials, molybdenum and tantalum, in a simulated nuclear waste glass melt was investigated using electrochemical (dc-powered) and non-powered tests. Electrochemical corrosion data showed that tantalum was more corrosion-resistant than molybdenum in this melt. Tantalum also showed passivation. The non-powered test data showed that tantalum corroded more than molybdenum. This was attributed to penetration of protective passivation layer at the tantalum-glass interface by the glass melt. Microstructural features and chemistry across selected electrode-glass interfacial regions supported these results.
Composition-Dependent Electrical Conductivity of Ionic-Electronic Composite
Authors: Park M. , Choi G. M. 
Published: April 2011

ABSTRACTComposition. dependence of electrical conductivity of ionic-electronic composite was camined using yttria(8mol%) stabilized zirconia-NiO composites. The contributions of ectronic and ionic charge carriers to the electrical conductivity were determined by Hebb-Vagner polarization technique and electromotive force measurement of galvanic cell. Up to 6 sol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in onic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effects of composition on he electrical properties were explained by the microstructure and thus by the distribution of two hases.
Microstructural and Electrical Characterization of Misfit Dislocations at the InAs/GaP Heterointerface
Authors: Gopal V. , Chin T. P. , Vasiliev A. L. , Woodall J. M. , Kvam E. P. 
Published: April 2011

ABSTRACTInAs is a narrow band gap semiconductor with potential for such applications as IR detectors, low temperature transistors, etc‥ However, the lack of suitable substrates has hampered progress in the development of InAs based devices. In the present study, InAs was grown by Molecular Beam Epitaxy on (001) GaP substrates. Though this system has a high lattice mismatch, (∼11%), certain MBE growth conditions result in 80% relaxed InAs layers on GaP with the mismatch accommodated predominantly by 90° pure edge dislocations. Misfit dislocation microstructures were studied using Transmission Electron Microscopy. Electrical characterization using lateral conductance and Hall effect measurements were also performed. Preliminary results indicate the possibility of misfit dislocation related conductivity. The possible correlation between interface structure and electrical properties is discussed.
Analysis of Teos Silicon Dioxide: The Identification of Carbonatious Contaminants
Authors: Pereira Da Silva M. L. , Romanelli Cardoso A. , Santiago-Aviles J. J. 
Published: April 2011

ABSTRACTThis work presents the analysis performed on a SiO2 film deposited from organometallic precursors with the aim of correlating their physico-chemical properties including electrical characteristics with processing variables. The characterization tools used in this study included SEM for film homogeneity; SIMS for the determination of total carbon content; FT-MS and Raman scattering spectroscopy for surface characterization. GC-MS was used to understand the electrochemical reactions taking place while performing I-V characteristics measurements.The use of these multiple characterization techniques pointed out to deposited films with reasonable deposition characteristics but poor electrical ones. Phase segregated heterogeneity's rich in carbonatious residues influenced the degradation of the electrical characteristics.
Particle and UV-Imaging with Position Sensitive MCP-Detectors-Three-Dimensional Momentum Space Imaging
Authors: Mergel V. , Jagutzki O. , Spielberger L. , Ullmann-Pfleger K. , Dörner R. , Schmidt-Böcking H. 
Published: April 2011

ABSTRACTVarious position sensitive microchannel-plate (MCP) detector systems for ion, electron and photon detection are presented. We have also developed a complete set of electronics to operate the detectors and software to analyze the incoming data. The detectors provide two-dimensional position as well as excellent timing information, e.g. for time-of-flight measurements. All data can be stored in single event mode. These MCP-detectors were used for electron and ion analyzers, which provide a three-dimensional imaging of the momentum space of all detected particles.