batterydata/paper-abstracts huggingface dataset:
Validated tests are important assessment tools for the detection and monitoring of an individual’s level of cognitive functioning. While the psychometric properties of these tests are reliable, sensitive, and specific, the proper conduct of the assessment and interpretation of the results are crucial to the usefulness and applicability of the findings. This chapter provides an overview of some of the more widely used assessment tools. The Mini-Mental State Examination, Montreal Cognitive Assessment Scale, Elderly Cognitive Assessment Questionnaire, and Abbreviated Mental Test Score are brief screening tools effective for bedside assessments and first-level case identification in the community. The Repeatable Battery for the Assessment of Neuropsychological Status, Wechsler Adult Intelligence Scale, and Wechsler Memory Scale are longer, more detailed instruments that require a higher level of training for administration. These assessment tools, together with the clinical history, biochemical findings, and neuroimaging findings, will provide a comprehensive overview of the level of cognitive functioning and diagnostic accuracy in individuals with cognitive decline. They are also useful in investigating the efficacy of interventions, such as modulations in diet or administration of dietary components.
Polysulfide (PS) shuttle, which is one of the critical problems that need to be addressed for realizing lithium sulfur batteries, can be suppressed by confining PSs within microporous or mesoporous templates. However, PS dissolution through the external opening of the templates has to be further prevented. In this work, a poly (3,4-ethylenedioxythiophene) (PEDOT) layer is formed in situ on the CMK-3/S cathode by inducing the electro-oxidative polymerization of the EDOT monomer included in electrolytes during pre-charging. The PEDOT layer covering the external cathode surface functions as a PS blocking layer, which suppresses the PS shuttle and, thus, improves the cycling stability. The spectroscopic analysis indicates that the PEDOT layer reduces the decomposition of the electrolyte by preventing any reaction between the active PS species and electrolytes. Therefore, the in situ formation of the PS blocking layer from the electrolyte additive provides a simple and effective method to improve the cycling stability of lithium sulfur batteries.
Carbon nanocoils (CNCs) have been used as anode materials for preparation of lithium ion batteries. As pure carbon material without any chemical modification, the graphitized CNCs anode exhibited larger capacities with good Coulombic efficiency, a higher rate capability, and better reversibility than the hollow graphite fibers (HGFs) anode. The excellent performance of the CNCs was possibly ascribed to the special structure and the high degree of graphitization. As a result, the CNCs anode exhibited high reversible capacity of 385.5mAhg−1 at 50mAg−1, 104.7% reversible capacity retention after 105 cycles, and superior reversible capability of 177.4mAhg−1 at 1Ag−1 after 100 cycles. This result indicated that CNCs could be an attractive choice as anode material for high-energy density and high-power lithium-ion batteries.
Li-rich cathode material Li1.2Mn0.54Ni0.13Co0.13O2 is prepared by a sol–gel method and coated with CaF2 layer via a wet chemical process. The pristine and CaF2-coated samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). An amorphous nanolayer coating of CaF2 is obtained on the surface of layered pristine material. The CaF2-coated Li1.2Mn0.54Ni0.13Co0.13O2 material exhibits excellent electrochemical performance. The initial coulombic efficiency is enhanced to 89.6% with high initial discharge capacity of 277.3mAhg−1 after CaF2 coating. Galvanostatic charge–discharge tests at 0.2C display faster activation of Li2MnO3 phase and higher capacity retention of 91.2% after 80 cycles for CaF2-coated material. Meanwhile it also shows higher rate capability with the capacity of 141.5mAhg−1 at the 3C-rate and stable cyclic performance above 190mAhg−1 after 100 cycles at the 1C-rate. The analysis of dQ/dV plots and electrochemical impedance spectroscopy (EIS) indicates that the obvious improvement of CaF2 coating is mainly attributed to the accelerated phase transformation from layered phase to spinel phase and stable electrolyte/electrode interfacial structure due to the suppression of the electrolyte decomposition.
The in situ electrochemical impedance spectroscopy (in situ EIS) in which the impedance spectra are measured simultaneously with the charge (intercalation)—discharge (deintercalation) sequence of lithium-ion rechargeable batteries has been developed. This method was applied to the investigation of the graphite electrode of lithium-ion rechargeable batteries. The resistance R sei for lithium-ion permeation in the solid electrolyte interphase (SEI) film were determined, and the formation mechanisms of SEI was discussed. Moreover, the role of vinylene carbonate (VC) as an additive to LiPF6–ethylene carbonate/ethyl methyl carbonate electrolyte solution was investigated. It was clarified that R sei decreases by the addition of VC, indicating the formation of a high quality SEI film.
Beta-cyclodextrin (β-CD) was first ground among the single stranded linear polyethylene glycol (PEG), and then the ZnO/PVA/β-CD/PEG composite electrode was prepared by chemical crosslinking method. From the SEM diagram of the composite electrode after 80 cycles, it can be seen that the internal and surface of the electrode was distributed a large number of holes within the average diameter of 150 μm. These holes have formed the interpenetrated three-dimensional framework with the active ZnO embedded in and no dendrite formation. The results show that the discharge capacity of the composite electrode is reduced to 80% of the maximum capacity after 130 cycles, which indicates that the cycle life of the composite electrode is longer than that of the blank electrode. The results of polarization curve test shows that the maximum dissolution current of the composite electrode was increased from 60 to 280 mA·cm−2 after 80 cycles, indicating that the activity of the composite electrode was still good after 80 cycles. Compared with it, the blank electrode had few activities after 80 cycles.
A significant advantage of direct methanol fuel cells (DMFCs) is the high specific energy of the liquid fuel, making it particularly suitable for portable and mobile applications. Nevertheless, conventional DMFCs have to be operated with excessively diluted methanol solutions to limit methanol crossover and the detrimental consequences. Operation with diluted methanol solutions significantly reduces the specific energy of the power pack and thereby prevents it from competing with advanced batteries. In view of this fact, there exists a need to improve conventional DMFC system designs, including membrane electrode assemblies and the subsystems for supplying/removing reactants/products, so that both the cell performance and the specific energy can be simultaneously maximized. This article provides a comprehensive review of past efforts on the optimization of DMFC systems that operate with concentrated methanol. Based on the discussion of the key issues associated with transport of the reactants/products, the strategies to manage the supply/removal of the reactants/products in DMFC operating with highly concentrated methanol are identified. With these strategies, the possible approaches to achieving the goal of concentrated fuel operation are then proposed. Past efforts in the management of the reactants/products for implementing each of the approaches are also summarized and reviewed.
California has taken steps to reduce greenhouse gas emissions from the transportation sector. One example is the recent adoption of the Low Carbon Fuel Standard, which aims to reduce the carbon intensity of transportation fuels. To effectively implement this and similar policies, it is necessary to understand well-to-wheels emissions associated with distinct vehicle and fuel platforms, including those using electricity. This analysis uses an hourly electricity dispatch model to simulate and investigate operation of the current California grid and its response to added vehicle and fuel-related electricity demands in the near term. The model identifies the “marginal electricity mix” – the mix of power plants that is used to supply the incremental electricity demand from vehicles and fuels – and calculates greenhouse gas emissions from those plants. It also quantifies the contribution from electricity to well-to-wheels greenhouse gas emissions from battery-electric, plug-in hybrid, and fuel cell vehicles and explores sensitivities of electricity supply and emissions to hydro-power availability, timing of electricity demand (including vehicle recharging), and demand location within the state. The results suggest that the near-term marginal electricity mix for vehicles and fuels in California will come from natural gas-fired power plants, including a significant fraction (likely as much as 40%) from relatively inefficient steam- and combustion-turbine plants. The marginal electricity emissions rate will be higher than the average rate from all generation – likely to exceed 600gCO2 equiv.kWh−1 during most hours of the day and months of the year – and will likely be more than 60% higher than the value estimated in the Low Carbon Fuel Standard. But despite the relatively high fuel carbon intensity of marginal electricity in California, alternative vehicle and fuel platforms still reduce emissions compared to conventional gasoline vehicles and hybrids, through improved vehicle efficiency.
Different approaches for lifetime prediction for electrochemical energy storage devices are discussed with respect to their general concepts. Examples for their implementation and advantages and disadvantages are given. The models are based on: (a) physical and chemical processes and their interaction as regards ageing effects; (b) weighting of the Ah throughput whenever the operating conditions deviate from the standard conditions used for determining the lifetime under laboratory conditions; (c) an event-oriented concept from mechanical engineering (Wöhler curves) which is based on a pattern recognition approach to identify severe operating conditions. Examples and details are explained for lead-acid batteries. The approaches can be applied to other electrochemical technologies including fuel cells. However, it is beyond the scope of this paper, to describe the models in all mathematical details. The models are used in system design and identification of appropriate operating strategies and therefore they must have high computational speed to allow for a comparison of a large number of system variations.
Lithium manganese oxides are of great interest due to their high theoretical specific capacity for electrochemical energy storage. However, it is still a big challenge to approach its large theoretical limit. In this work, we report that Li2MnO3 nanorods with layered structure as superior performance electrode for supercapacitors. The synthesized Li2MnO3 nanorods possess large specific surface area of 179.5m2/g. The electrode made of the as-obtained Li2MnO3 nanorods exhibits high specific capacitance of 1129.5F/g at 2mV/s in 3M LiCl electrolyte. Detailed electrochemical analysis shows that diffusion controlled processes contribute most of the relative capacity. First-principles calculations within density functional theory also show that the diffusion of Li+ ions in the lithium layer is much easier than that in the manganese-lithium-oxygen layer. Therefore, the ion flow in lithium layer provides most of the high specific capacitance during charge/discharge. A flexible symmetric supercapacitor is assembled based on Li2MnO3/carbon fabric cloth. Such device demonstrates high specific capacitance, high energy density, high power density and excellent cycling stability. Three supercapacitors in series can efficiently power 288 blue LEDs in parallel for about 11min. These results indicate that Li2MnO3 nanorods are very promising as super electrode material for supercapacitors.
The World Health Organization (WHO)'s "3 × 5 program" has spurred efforts to place 3 million people on combination antiretroviral therapy (ART) for treatment of AIDS in resource-limited countries. Paradoxically, the cost of CD4+ T-lymphocyte count essential for decision-making to commence HIV positive adults on ART as well as for monitoring responses to ART remains unaffordable in most resource-limited countries. Thus, low-cost methods for enumerating CD4+ T-lymphocyte are urgently needed.
We assembled a sodium-ion capacitor (Na-IC) by combining sodium pre-doped hard carbon (HC) as the negative- and activated carbon (AC) as the positive-electrode. The electrochemical properties were compared with two lithium-ion capacitors (Li-ICs) in which the negative electrodes were prepared with Li pre-doped HC and mesocarbon microbeads (MCMB). The positive and negative electrodes were prepared using the established doctor blade method. The negative electrodes were galvanostatically pre-doped with Na or Li to 80% of the full capacity of carbons. The potential of the negative electrodes after pre-doping was around 0.0V vs. Na/Na+ or Li/Li+, which resulted in the higher output potential difference of the Na-IC and Li-ICs than that of the conventional electrochemical double-layer capacitors (EDLCs) because AC positive electrode works in the same principle both in the ion capacitors and in the EDLC. The state-of-charge of the negative electrode varied 80±10% during the electrochemical charging and discharging. The capacity of the cell was evaluated using galvanostatic charge–discharge measurement. At the discharge current density of 10mAcm−2, the Na-IC maintained 70% of the capacity that obtained at the current density of 0.5mAcm−2, which was comparable to the Li-ICs. At 50mAcm−2, the capacities of the Li-IC(MCMB) and the Na-IC dropped to 20% whereas the Li-IC(HC) retained 30% of the capacity observed at 0.5mAcm−2. The capacities of the Na-IC and Li-ICs decreased by 9% and 3%, respectively, after 1000 cycles of charging and discharging.
Formation of battery plates can be conducted via two technological schemes: (a) Tank formation. 50–200 cured positive and negative plates are arranged in a tank with H2SO4 solution of 1.06 relative density. After soaking for 1–2hours, formation proper starts. (b) Container (jar) formation. Cured positive and negative plates, with separators between them, are assembled into “plate groups” which are then placed in battery containers. H2SO4 solution of 1.15–1.23 rel. dens. is used. Formation starts after 1–2hours of soaking.
The purpose of this paper is presenting a reliable modelling of sodium-nickel chloride battery in order to have a powerful tool which is able to foresee the steady state battery behaviour in both discharge and charge operations. The proposed modelling approach allows representing both constant current operations and variable charge or variable discharge current ones, but it does not allow passing instantaneously from one battery mode to another one. This method is based on experimental measures. All the main modelling steps are described and a comparison between the model results and real battery measures, with the same conditions, is presented. The very good agreement between measures and model confirms the robustness of the approach for steady state applications. The paper proposes to adopt a set of standard battery measures from which it is possible to infer a simple but very precise modelling structure.
The development of low-cost efficient bifunctional oxygen electrocatalysts is of importance for optimizing the performance of metal-air batteries. By using manganese dioxide spheres as both the redox initiator and the self-sacrificing template for the in-situ interfacial polymerization of aniline monomers, we demonstrated a facile approach to preparing porous polyaniline spheres in the presence of phytic acid. Subsequent pyrolysis led to nitrogen and phosphorous co-doped carbon spheres (NPCSs) with highly porous structure and good bifunctional electrocatalytic activities for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Specifically, NPCSs exhibited a comparable half-wave potential (0.83 V vs. RHE) to that of commercial Pt/C, but a larger current density, for ORR and was superior to RuO2 (overpotential, 320 mV) for OER with a smaller overpotential of 310 mV. The Density Functional Theory (DFT) calculations revealed firstly that the heteroatom-doping at the edges of the porous structure plays a dominate role in achieving the high bifunctional catalytic activities. Furthermore, the bifunctional oxygen electrocatalysis enabled the fabrication of high-performance Zn-air batteries in aqueous and solid-state electrolytes, exhibiting large energy density, high power density, and good cycling stability.
The literature on changes in health-related quality of life (HRQOL) in weight loss studies is inconsistent, and few studies use more than one type of measure. The purpose of the current study was to compare one-year changes in HRQOL as a function of weight change using three different measures: a weight-related measure (Impact of Weight on Quality of Life-Lite [IWQOL-Lite)]) and two generic measures (SF-36; EQ-5D).
Transport and thermodynamic properties of electrolyte solutions are very essential for development and design of lithium ion or lithium polymer batteries. An electrolyte database for lithium battery, which includes a quite number of organic solvents, lithium electrolytes and possible by-products (e.g. CO2), has been compiled. Appropriate models have been evaluated for representing the variety of properties for solvents and electrolyte solutions, such as, conductivity, transference number, diffusivity, dissociation constant and so on. Particular attention has been given on conductivity in this paper, considering its essential importance for battery; several typical examples have been presented and discussed.
Considering the abundance and low price of sodium, sodium-ion batteries (SIBs) are of particular attractiveness for large-scale electrochemical energy storage. Layered P2–Na2/3Mn1/2Fe1/4Co1/4O2 (NMFC) is a promising cathode material for SIBs because of its large theoretical capacity, however, its high air sensitivity and poor cycling stability seriously limits the practical use. Here, we report nanometre-thick Al2O3 coating of NMFC electrode through atomic layer deposition (ALD) technique can effectively alleviate such deficiencies to obtain an air-insensitive electrode, which was realized by effectively preventing the direct exposure of NMFC to H2O and CO2 present in the air atmosphere. Interestingly, the ultrathin Al2O3 coating did not cause a block for sodium ion intercalation, and a high capacity of 217.9 mA h g−1 at a high cut-off potential of 4.5 V was achieved. More attractively, a capacity retention rate as high as 84.8% was obtained after cycling at a current density of 0.5C over 100 cycles, demonstrating improved electrochemical stability. Based on CV and EIS characterizations, such good cycling stability is associated with the use of the Al2O3 coating layer as well, which effectively avoided the side reactions at the interface of the liquid electrolyte and the active material under high potential.
Gel-type polymer electrolytes are prepared using PVdF/PEGDA/PMMA, LiPF6/LiCF3SO3 mixed lithium salts and ceramic fillers such as Al2O3, BaTiO3 and TiO2. The electrochemical properties of these electrolytes, such as electrochemical stability, ionic conductivity and compatibility with electrodes are investigated in addition to the physical properties. The charge–discharge performances of lithium-ion polymer batteries using these get-type polymer electrolytes are investigated. The gel-type polymer electrolytes containing a mixed lithium salt of LiPF6/LiCF3SO3 (10/1, wt.%) exhibit more stable ionic conductivity and lower interfacial resistance than those containing only LiPF6. In addition, an Al2O3 filler improves interfacial stability between the electrode and the polymer electrolyte. Stacking cells (MCMB 1028/LiCoO2, 8cm×13cm×7ea) composed of gel-type polymer electrolytes based on PVdF/PEGDA/PMMA, LiPF6/LiCF3SO3 (10/1, wt.%) and Al2O3 filler maintain 95% of initial capacity after 100 cycles at a C/2 rate.
ABSTRACT Electrolyte compositions based on LiTFSI dissolved in fluorinated linear and cyclic carbonates were characterized regarding their transport and thermal properties, viscosity, solvation ability, electrochemical stability towards oxidation, as well as their ability to inhibit the aluminum current collector corrosion. As a result of the thorough investigation, different binary mixtures were prepared, which offer beneficial properties in terms of aluminum current collector protection and provide optimized transport properties. The use of LiTFSI as electrolyte salt rather than the state-of-the-art lithium salt, LiPF6, enables substantial improvements with respect to safety, while maintaining high performance liquid electrolyte.
This paper reports a co-precipitation synthesis of TiP2O7–graphene (10wt%) nanocomposite and pure TiP2O7 nanoparticles for the use as an advanced anode material for high performance lithium-ion batteries. The structure and morphology of the compounds are characterized by powder X-ray diffraction, field-emission scanning electron microscopy and field-emission transmission electron microscopy techniques. The electrochemical performances were evaluated in coin type Li-ion test cells. This TiP2O7–graphene nanocomposite displayed superior Li-ion battery performance with a large reversible capacity, excellent cyclic performance and good rate capability at a current density of 0.1mAcm−2. At an elevated current density of 6.4mAcm−2, the nanocomposite anode delivered a capacity of 98.4mAhg−1, which is much higher than that of pure TiP2O7 (0.56mAhg−1). The impressive electrochemical performance of the nanocomposite was ascribed to the synergistic effect of the high surface area nanoparticles in conjunction with the good electronic conductivity of graphene. The graphene nanosheets not only provide an electronically conducting network, but also tend to prevent the aggregation of the high surface area TiP2O7 nanoparticles. Further, the graphene nanosheets can act as buffer layers to accommodate the volume change during the Li-ion insertion/extraction processes in the TiP2O7 nanoparticles.
After hospitalization for cardiac disease, older patients are at high risk of readmission and death. Although geriatric conditions increase this risk, treatment of older cardiac patients is limited to the management of cardiac diseases. The aim of this study is to investigate if unplanned hospital readmission and mortality can be reduced by the Cardiac Care Bridge transitional care program (CCB program) that integrates case management, disease management and home-based cardiac rehabilitation.
Pursuing the electrochemical evaluation vs. Li of carbonyl-based cyclic structures deriving from the oxocarbon family, polyketones with N-cyclic structure are investigated to probe the potential modifications. In this communication, we specifically report on the electrochemical investigation of our first selected family of heterocycles based on the 2,3,5,6-tetraketopiperazine unit. Working in a systematic way, a series of tetraketopiperazine molecules with quite different R groups as substituents (i.e., phenyl, allyl and propyl functions) have been synthesized and characterized. Such small molecules were found to rapidly solubilise in commonly used electrolytes. To bypass this issue, we have prepared an oligomeric form via acyclic diene metathesis (ADMET). Preliminary results on the poly-N,N′-diallyl-2,3,5,6-tetraketopiperazine oligomer show a sustained reversible capacity of 110 mAh g−1 at near 2.45 V. The insight gained from this work is the fact that two intracyclic nitrogen atoms or a lithiated ene–diolate functionality in the C6-based polyketone cyclic structure induces a similar tuning of the redox potential.