batterydata/paper-abstracts huggingface dataset:
The complex nature of lithium ion batteries makes the tracking of individual physical processes difficult. However, having a good knowledge thereof is indispensable for a continuous improvement of cell performance and lifetime. In this study, the impedance response of a commercial 18650 cell was investigated within a wide frequency range (100 kHz–2 μHz) by combining electrochemical impedance spectroscopy and time domain measurements. In parallel, the original 18650 cell was opened. Thus, the electrode materials could be tested in an experimental test set-up using a reference electrode, which allowed the separation of anode and cathode processes. The different kinds of impedance data sets were de-convoluted in the space of relaxation times, enabling a refined separation of physical processes like charge transfer or solid state diffusion. This multistep approach, which is not tied to a particular electrochemistry, allowed the identification of the dominating physical processes being hidden in the impedance spectrum of the original 18650 cell.
A flexible felt consisting of electrospun anatase TiO2 and amorphous SiO2 nanofibers together with anatase TiO2 nanoparticles was explored as an innovative anode material for lithium ion battery. The electrochemical characterization of the half-cell of the composite felt (vs. Li metal) showed that the felt had a high initial discharge capacity of 170 mAh/g and an excellent rate capability; furthermore, the capacity was retained at 84% of initial value after 100 cycles at fast charge/discharge rate of 1A/g. The binder-free composite felt maintained superior flexibility/robustness and good electrochemical performance after 5,000 continuous bending cycles.
The charge/discharge characteristics of sulfurized polyacrylonitrile composite (SPAN) cathodes with different sulfur content in conventional carbonate based electrolyte for rechargeable lithium batteries have been investigated. The good performance of SPAN in the carbonate based electrolyte indicates a material difference between SPAN and elemental sulfur/carbon composite materials. The SPAN with sulfur contents of 33.7%, 42.0% and 46.3% are prepared by control of heating time. The SPAN with sulfur content of 42.0% shows the best electrochemical performance, it can deliver stable cycling capacity over 700mAhg−1, and keep capacity retention over 97% after 80 cycles in the electrolyte of 1M LiPF6/EC+DEC. The average capacity degradation rate is less than 0.03% per cycle excluding the first discharge capacity. Prototype 100mAhLi/SPAN cell is assembled, showing energy density of 437Whkg−1 excluding the weight of package and capacity retention of 90.4% after 30 cycles at 100% depth of discharge. This study demonstrates that the sulfurized polyacrylonitrile composite in the electrolyte of 1M LiPF6/EC+DEC is a promising battery chemistry, which materials are abundant, of low cost and easily available, to fabricate Li/SPAN batteries, paving an alternative avenue to develop high performance lithium batteries for energy storage and vehicular application.
To investigate endorsement patterns among the 18 DSM-IV symptoms of ADHD in a longitudinal sample of children with and without ADHD (n = 144), as assessed at ages 4-5, 5-6, and 6-7 years. Symptom endorsements and diagnoses were determined at all time-points via K-SADS-PL interview administered to parents and supplemented by teacher questionnaires and clinician observations. Changes in endorsement patterns over time for each of the 18 DSM-IV symptoms were ascertained. Several symptoms, particularly those of inattention, were infrequently endorsed and of apparently limited diagnostic utility at ages 4-5; hyperactive/impulsive symptoms were more frequently endorsed among young children with ADHD than were inattentive symptoms. However, by ages 6-7, inattention items were somewhat superior at discriminating ADHD from Non-ADHD children. Several DSM-IV and now DSM-V symptoms provide limited diagnostic differentiation prior to school-age, particularly those most commonly observed in the context of formal schooling. Consideration should be made in future iterations of the DSM that account for such developmental and contextual differences.
In both clinical and occupational settings, ambulatory sensors are becoming common for assessing all day measurements of arm motion. In order for the motion of a healthy, contralateral side to be used as a control for the involved side, the inherent side to side differences in arm usage must be minimal. The goal of the present study was to determine the reliability of side to side measurements of upper extremity activity levels in healthy subjects.
The anode properties of Nb-doped rutile TiO2 electrodes were investigated in an ionic liquid electrolyte comprised of N-methyl-N-propylpyrrolidinium cation and bis(fluorosulfonyl)amide anion for use in a safe Na-ion battery. Although the electrolyte's conductivity was lower than that of a conventional organic electrolyte at 30 °C, it showed high conductivity comparable to that of the organic electrolyte at 60 °C. The Nb-doped TiO2 electrode showed excellent cyclability in the ionic liquid electrolyte at 60 °C: a high capacity retention of 97% was observed even at the 350th cycle, which is comparable to value in the organic electrolyte (91%). In a non-flammability test in a closed system, no ignition was observed with the ionic liquid electrolyte even at 300 °C. These results indicate that combination of a Nb-doped TiO2 anode and ionic liquid electrolyte gives not only an excellent cyclability but also high safety for a Na-ion battery operating at a temperature below the sodium's melting point of 98 °C.
Constructing 3D heteroatom-doped carbon framework from sp2-hybridized nanocarbon (graphene) and sp3-hybridized porous carbon (activated carbon) has been considered as an effective method to achieve excellent performance in energy conversion and storage due to the synergistic effect between building blocks. Herein, a facile assembly of graphene oxide and porous carbon is reported to fabricate the inherent nitrogen-doped porous carbon and graphene composited nanostructures. When used as the sulfur scaffold for lithium sulfur batteries, the materials suggest outstanding electrochemical properties, including a high reversible capacity (1372 mAh g−1 at 0.1C), excellent rate performance (451 mAh g−1 at 3C) and cycling stability (579 mAh g−1 at 1C after 500 cycles). The enhancement in electrochemical properties can be ascribed to the 3D hierarchical porous structure of the carbon hybrid, in which, besides, the inherent doping of nitrogen can generate homogeneous active sites and defects that can effectively improve the interfacial adsorption. Thus, the simple strategy of pyrolysis and self assembly of graphene oxide and porous carbon provided in this work opens a new avenue for combining different dimensional nanocarbons to construct nitrogen-doped, multi-dimensional carbon architecture for high performance lithium sulfur batteries.
High oxygen radical stability of electrolyte solvent is a key parameter necessary to overcome a large voltage gap in discharge–charge profiles of the non-aqueous Li–air battery. We have proposed N-methyl-N-propylpiperidinium bis(trifluoromethansulfonyl)amide (PP13TFSA) as an appropriate candidate of the electrolyte solvent. PP13TFSA based Li–O2 cells enabled us to draw low charging voltage of around 3.3 V, lowering the voltage gap by nearly half in comparison with those of conventional carbonate-based cells (c.a. 1.4 V). Here, through the detailed analyses of discharge products, we verified the fact that the voltage gap was notably decreased by using the highly radical stable electrolyte solvent. TEM-EELS and FT-IR analyses indicated that Li2O2 was deposited as a discharge product. 13C NMR spectroscopy suggested that no decomposed species derived from electrolyte decomposition was observed from a discharged cathode. GC–MS analyses also revealed that CO and CO2 gases as indices of the decomposed species were not monitored at all. Above-described data substantiated a desirable discharge reaction, resulting in low charging voltage as well as small voltage gap. Design of electrolyte solvents based on their oxygen radical stability and full understanding of the cathode reaction mechanism contributed greatly to a dramatic improvement of the Li–air battery performances.
Cognitive functioning was compared in elderly patients with schizophrenia, elderly patients with probable Alzheimer's disease (AD), and matched healthy controls using a brief neuropsychological battery. Both schizophrenia and AD patients demonstrated marked impairment as compared to controls, with the profile of neuropsychological deficits in both disorders appearing remarkably similar. Only visual confrontation naming, verbal delayed recall, and rate of forgetting (i.e. savings score) significantly differentiated between the two patient groups, with AD patients showing poorer overall recall and more rapid forgetting of verbal information over delay. In addition, schizophrenia subjects showed a significantly greater deficit in visual confrontation naming than the AD group. The relationship of neuropsychological function and clinical symptoms of schizophrenia subjects was also examined. Results showed that word list learning, delayed recall, and rate of forgetting correlated most strongly with positive and negative symptoms. Recent neuropathological studies have indicated abnormalities in specific subfields of the hippocampal formation in schizophrenia that are also severely affected in AD. Though the specific histopathology of the two disorders differs, abnormalities in the common sites may underlie the common neuropsychological profile.
From thermal engine equipped vehicles to completely electric ones, evolution of light weight vehicles in the future will take several steps in so far as there is no adequate battery or fuel cell presently available to power these vehicles for “on the road” driving. On the other hand, for city driving, vehicles can be improved a lot in terms of fuel efficiency as well as air pollution, if partly or totally electric propulsion can be developed, manufactured and marketed for appropriate applications. The 36–42V battery is part of this orientation towards improving the efficiency of thermal vehicles in city driving, while keeping adequate autonomy on the roads. Actually, in city traffic, thermal engines are idle most of the time and stop periods represent a large part of the time spent “driving”, using up fuel and polluting air for no use at all. The idea of stopping the engine during these periods, if appropriately managed, might potentially lead to a large improvement in fuel economy as well as air pollution reduction. The association of a higher voltage battery to an alternator–starter device in thermal vehicles, seems to be an interesting way towards that end. In this paper, we are presenting our results of a study we have just completed in relationship with RENAULT & VALEO, supported by the French Ministry of Industry, concerning a comparative evaluation of different automobile energy storage systems, and the definition of specifications as the final step of this study. The main conclusion is that lead-acid will still remain dominant in this role, since its operational cost versus efficiency is by far the lowest of every battery presently considered, more particularly in the less expensive car segments.
Abstract Porous carbons have been extensively studied as double layer capacitors due to their large surface area, chemical stability, easy processability and long cycle life. However, they have low conductivity and the energy storage occurs mainly through double layer mechanism. The addition of a conducting polymer thin film can improve the performance of the porous carbon and open the possibilities for preparing advanced carbon materials. This review focuses in the methods for the synthesis of conducting polymer/carbon composites, for their application in electrical energy storage and the synthesis of advanced carbon materials.
The surface coating of dual-conductive layers is implemented to optimize the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 (NCM) under high cut-off voltage (4.5 V) by the integrated use of sol-gel method and in-situ chemical polymerization. The X-ray powder diffraction (XRD) and Rietveld refinements results indicate that the dual-conductive layers hardly affect the crystal structure of NCM. Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), and field emission transmission electron microscopy (FETEM) results confirm that the dual-conductive layers with Li3VO4 and polypyrrole (PPy) are successfully coated on the spherical particle surface and inhibit the dissolution of transition metals from crystal structure. The Li3VO4-PPy coated NCM sample exhibits excellent cycling stability at 0.5 C (1 C = 180 mAh/g) under high cut-off voltage (4.5 V), with a retention rate of 93.7% compared to 73.6% for the pristine NCM after 100 cycles. Moreover, it also shows super cycling performance at large current (2 C) with a retention rate of 93.8%, whereas the pristine NCM is only 61.6% after 100 cycles.
The overall goal of nuclear power plant safety is to protect individuals, society and the environment from undue radiological hazard so that nuclear power production does not significantly add to the health risks to which individuals and society are already exposed. This paper addresses the safety principles followed during the design phase of life cycle of a nuclear power plant. The principles followed such as safety classification, design rules based on failure modes, detailed stress analysis, stress categorization, consideration of design basis events, failure probability, flaw tolerance, leak-before-break are described. Engineering structures always contain flaws, albeit of very small size. Fatigue and fracture are the two important failure modes affected by flaws. Thus flaw tolerance becomes very important. This is assessed by applying fracture mechanics principles. The R6 procedure, which is used for evaluation of structures containing flaws, has been incorporated in the software BARC-R6. Improvements by way of shell-nozzle junction pull-out, adoption of hot wire GTAW with narrow gap technique have been brought out. Post Fukushima incidence, resistance to seismic loading and containment design have assumed great importance. The paper describes these aspects in detail. Regulatory aspects of seismic design regarding siting, Seismic margin assessment, base isolation, retrofitting are the aspects covered under seismic design. Under the action of seismic loading, the piping in a nuclear power plant piping is vulnerable to a phenomenon called ratcheting. The process of seismic margin assessment and consideration of ratchetting has been backed up by a large experimental data. The experiments carried out on structures and piping components form a part of the paper.
Consumers are often confronted with value-laden decisions that challenge their principles and beliefs. For example, many consumers with strong social responsibility principles consider the effects of general corporate behavior (e.g., political views, environmental disasters) and of the product's manufacture, consumption, or disposal (e.g., animal testing, environmental harm) on society's overall well-being. Because these product dimensions do not fit easily into traditional decision theories, a new conceptual framework that incorporates and emphasizes the consumer's enduring principles and values is explored in this study. The results indicate that image theory (Beach & Mitchell, 1987) provides a useful structure for describing the decision process in a value-laden decision context. This study also expands our understanding of image theory by examining all 3 images (values, goals, and strategies) simultaneously in the same decision context for the first time.
Flexible lithium ion batteries (LIBs) have received considerable attention as a key component to enable future flexible electronic devices. A number of designs for flexible LIBs have been reported in recent years; in this article, we review recent progress. We focus on how flexibility can be introduced into each component of the LIB, including the active materials, electrolytes, separators, and current collectors. Approaches to integrating each component into a single device are described and the corresponding changes in the electrochemical and mechanical properties are discussed. Finally, the key challenges in the development of flexible LIBs are summarized.
Carbon electrodes have been modified with 2-nitro-1-naphthol with the aim of producing composite supercapacitor electrodes, which make use of both the electric double layer (EDL) capacitance of high surface area carbon and the redox capacity (pseudocapacitance) of the organic compound. In situ FTIR and cyclic voltammetric data confirm literature reports of the reduction of 2-nitro-1-naphthol to 2-amino-1-naphthol and the subsequent oxidation of the o-aminonaphthol to the corresponding o-naphthaquinoneimine in aqueous acidic media. The measurements also show that the quinoneimine is not stable and hydrolized in sulphuric acid electrolyte to 1,2-naphthaquinone. The chemically highly reversible o-naphthaquinone/o-naphthahydroquinone couple remains immobilized on the carbon electrodes during redox cycling. The organic redox couple contributes a capacity of 35mAhg−1 of the bare carbon to the overall charge storage capability of the composite electrode. Surprisingly, it does not affect the capacitance of the electric double layer of the carbon. During 1000charge/discharge cycles, the pseudocapacitance decreases by less than 20% in a normal large-volume electrochemical cell. Electrochemical impedance measurements show that the full capacity of the electrode is accessible at frequencies below 0.1Hz.
Recently, Ni3.5Sn4 intermetallic has been reported as an efficient buffering material for Si-containing composite negative electrodes used in Li-ion batteries. In the present work, the electrochemical properties of this Ni-overstoichiometric compound are studied in detail. Micrometric, nanosized and carbon-added nanosized Ni3.5Sn4 have been investigated. For all materials, very good cycle life is obtained over more than 400 cycles. Nanosized Ni3.5Sn4 with crystallite size of 6nm exhibits a reversible capacity of 240mAhg−1, ten times higher than for the micrometric state. Moreover, nanosized Ni3.5Sn4 exhibits high-rate capability with 80% of full discharge capacity at 16C. Carbon addition slows down kinetics but increases the reversible capacity up to 273mAhg−1. The electrochemical properties of nanostructured Ni3.5Sn4 phase make it a promising constituent for composite anodes of Li-ion batteries.
This work presents a novel fuel sensor-less control scheme for a liquid feed fuel cell system that operates under dynamic loading conditions and is suitable for portable power sources. The proposed technique utilizes the operating characteristics of a fuel cell, such as voltage, current and power, to control the supply of liquid fuel and regulate its concentration. As verified by systematic experiments, this scheme controls effectively the supply of fuel under dynamic loading conditions and pushes the system toward higher power output. The primary features and advantages of sensor-less fuel control are as follows. When the fuel concentration sensor is excluded, the cost of a liquid feed fuel cell system is decreased and system volume and weight are reduced, thereby increasing specific energy density and design simplicity, and shortening system response time. Notably, temperature compensation for measurement data is unnecessary. With a decreased number of components, the control scheme improves durability and reliability of liquid feed fuel cells. These advantages will help commercialization of liquid feed fuel cells as portable power sources.
Different samples of Sn and W-codoped TiO2
Nowadays, photocatalysis has attracted lively interest due to its potential applications in environmental remediation and clean energy production. Among various photocatalysts, TiO2
Visible light sensitive TiO2
Doping TiO2
In our previous research we studied the effect of doping Sn (up to 30 mol%) and Nb (up to 20 mol%) on photo-catalytic behavior of titania based thin films. We found that 15 mol% of Sn and 1 mol% on Nb shows the most significant improvement on photo-catalytic behavior of TiO2
However, very few studies of Sn,W co-doped TiO2
Tungsten doping is proven to be an efficient technique for solving the major problems associated with the use of titania as a photocatalyst. Having an ionic radius similar to that of titanium, tungsten is expected to be incorporated into the titania crystal lattice in a substitutional manner (Ratova et al. 2013). Several authors have reported significant improvements in the photoactivity of titania through doping it with tungsten (Farahani et al. 2011; Kubacka et al. 2009; Saepurahman et al. 2010; Rampaul et al. 2003). Li et al. described titania with 3 at.% of W as high activity photocatalyst for coatings deposited by the sol-gel method (Li et al. 2011), while Kubacka et al. found the optimum concentration to be significantly higher-19 at.%, with the coatings prepared by a microemulsion method (Kubacka et al. 2009).
The factors limiting the capacity of highly dense electrodes are elucidated by using composite electrodes for lithium-ion batteries, which consist of active materials LiNi1/3Co1/3Mn1/3O2 (NCM), conductive additives and binders. Electrochemical tests of such 100-μm-thick electrodes in 1 M LiPF6 electrolyte indicate that a highly dense electrode (with 18% porosity) shows a capacity density significantly lower than the other sparse electrodes on 1C charging/discharging. Detailed analysis using position sensitive in situ X-ray diffraction indicates that, unlike the other sparse electrodes, NCM on the current-collector side barely functions for this dense electrode, due to the poor accessibility of Li+ to the inner part of the electrode. Interestingly, 2 M and 0.3 M electrolytes promote the discharge and charge reactions, respectively, over the entire area of the electrode, although they exhibit lower conductivity than the 1 M electrolyte, which indicates the importance of the initial amount of Li+ in the electrolyte impregnated in the electrode pores. Thus, for a high-energy-density cell, the initial amount of Li+ and the Li+ transport significantly affect the rate capability, which governs the practical capacity of the cell under constant-current operation.
Electric capacity and electric conductance of lipid membranes composed of phosphatidylethanolamine and α-tocopherol were determined by electrochemical impedance spectroscopy. These components were chosen for the study because they are present in biological membranes and they fulfill essential functions in lively organisms. A domain structures appear as a result of phosphatidylethanolamine–α-tocopherol membrane formation. Formation of the domains can explain the deviation from the additivity rule. This equilibrium was described by mathematical equations and was further verified experimentally. Based on the derived equations, the surface area of domain was calculated; it amounts to 320Å2. This value is consistent, taking into consideration ordering and condensation effects of α-tocopherol on the phosphatidylethanolamine, with a stoichiometry of such a domain equal to 4:1.