batterydata/paper-abstracts huggingface dataset:
It has been established that addition of carbon additives to the lead negative active material (NAM) of lead-acid batteries increase battery charge acceptance in hybrid electric vehicle mode of operation. The present work studies three types of activated carbons and two types of carbon blacks with the aim to evaluate their efficiency in improving the charge acceptance of lead-acid batteries. It has been established that the size of carbon particles and their affinity to lead are essential. If carbon particles are of nanosizes, they are incorporated into the bulk of the skeleton branches of NAM and may thus increase the latter's ohmic resistance. Their content in NAM should not exceed 0.2–0.5wt.%. At this loading level, carbon grains are adsorbed only on the surface of NAM contributing to the increase of its specific surface area and thus improving its charge acceptance. When carbon particles are of micron sizes and have high affinity to lead, they are integrated into the skeleton structure of NAM as a structural component and act as super-capacitors, i.e. electric charges are concentrated in them and then the current is distributed along the adjacent branches of the lead skeleton with the lowest ohmic resistance. This eventually improves the charge acceptance of the negative battery plates.
Novel Sb2S3@multiwalledcarbonnanotubes(MWCNTs) (SM) composites were synthesized via a facile and green method which included an in-situ growth of Sb2S3 nanoparticles on the surface of MWCNTs through precipitation and subsequent thermal treatment. The morphologies and structures of SM composites were tested by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and nitrogen adsorption and desorption isotherms. Finally, their application as anode materials for sodium-ion batteries (SIBs) was investigated through corresponding electrochemical measurements such as galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the SM composites display higher capacity, better cycling stability and superior rate performance than pure Sb2S3, and a capacity of 412.3mAhg−1 after 50 cycles at 50mAg−1 is obtained for SM composites with 30wt.% MWCNTs loading. The enhanced performance is ascribed to an increase in the specific surface area, an improvement in the charge transfer and effective buffering of the volume change offered by the porous conductive network structure of the composite with the introduction of MWCNTs.
M.M., a right-handed, 74 year old professional musician and composer, presented with a progressive aphasia with a severe anomia. His musical competence was apparently totally preserved, and he continued his activity as a composer. There was a striking discrepancy between his impaired naming of nonmusical stimuli and his normal naming of musical instruments' sounds. We suggest that the preservation of skills in the musical domain results from an expanded cortical representation of this function in the left hemisphere, secondary to his lifelong formal training, and to the high level of his professional competence. As for his preserved naming of musical instruments, we argue that the early age-of-acquisition and higher than “normal” frequency/familiarity for names of musical instruments facilitate the access to their lexical representation and/or their retrieval within the lexicon.
Three-dimensional (3D) hollow nanostructure has been intensively investigated for preparing desirable anode material. Herein, VN hollow spheres are made up of porous nanosheets which were prepared through a one-step solvothermal route and followed with calcination process under ammonia atmosphere. Consequently, the obtained hollow sphere structure can provide large surface area and exhibiting unprecedented stable long cycling performance (456 mA h g−1 after 1100 cycles), when applied as an anode for lithium intercalation. Besides, the anode material also demonstrates a high capacitive contribution of 76.1% at 2 mV s−1 for the total charge.
The recent literature on applied energy has emphasized the role of energy storage in the electricity supply chain. However, absence of an integrated valuation framework for services provided by energy storage technologies, owed to its limited scope so far, hinders investments in such capital intensive systems. To this end, the feasibility of an alternative operation strategy for energy storage systems (ESSs), based on the use of wind energy surplus, is currently investigated. More precisely, valuation of the policy options available to promote wind-based ESSs is carried out, by employing, for the first time, a comprehensive socioeconomic cost-benefit model that takes into account – among others – initial investment subsidies and feed-in tariffs (FiTs) for ESSs. Pumped hydro and compressed air energy storage covering peak demand are examined, demonstrating that such systems may prove cost-effective if “socially just” FiTs are applied, with our findings however, also supporting the notion that a portfolio of policies can more effectively facilitate investments in the sector.
Since the first practical uses of fuel cells were developed, it has become clear that they could find use in many products over a wide power range of milliwatts to tens of megawatts. Throughout the 1990s, and later, there has been significant work carried out on adapting the various different fuel cell technologies for use in targetted consumer and industrial applications. This paper discusses these developments and gives details on the specific market segments for providing power to vehicles, portable devices and large- and small-scale stationary power generation.
We report a feasible design to fabricate micrometer-scale Si films deposited on nanostructured Cu foil as high areal capacity anodes for Li-ion batteries with excellent cycling performance. Nanostructured copper oxides are prepared by anodic oxidation of Cu foil in alkaline solution. The resultant copper oxide nanofibers function as matrix for thick Si films (1–2 μm) loading. Metallic Cu nanofibers are obtained by in-situ electrochemical reduction at low potentials, which work as electrical highways for fast electron transport and a reliable mechanical matrix to accommodate volume changes during lithium–silicon alloy/dealloy processes. The engineered thick Si film anode exhibit both high areal capacity (0.48 mAh cm−2 for 1 μm Si film and 0.6 mAh cm−2 for 2 μm Si film after 200 cycles at 0.225 mA cm−2) and excellent rate capability (0.52 mAh cm−2 at 1.05 mA cm−2 for 2 μm Si film). The 2 μm silicon film electrode is able to recover to the initial value of 1 mAh cm−2 when the current rate is set back to 0.15 mA cm−2 even after cycling at high current rates. The reported concept can be a general method for high-loading-film electrodes, which is industrial scalable and compatible with current battery manufacturing processes.
Biogenic 3-D SiO2 micro-assemblies (diatom microshells) of low specific surface area (SSA, <2 m2g−1) have been transformed into 3-D replicas of high SSA C (>1300 m2g−1) and Pt-loaded C (>600 m2g−1) by a shape-preserving serial reaction process. Such high SSA micro-assemblies may be generated in a wide variety of selectable 3-D shapes for tailored catalysis, filtration, or adsorption for energy storage/production, water purification, and biofuel separation.
This study of 118 students who placed into basic skills sections of College English suggests that students’ self-beliefs may be a particularly important predictor of success in weak writers in first-semester courses. Two types of writing self-efficacy scales—a writing tasks/skills scale and an approach-to-writing scale—were developed to follow current composition practice more closely. Locus of control was the single most powerful predictor of success. This finding is congruent with theory about the importance of locus of control in new and ambiguous situations. High school performance, writing proficiency, and negative academic behaviors were also significant factors in regression analyses for both course grade and writing proficiency test. Various ways that writing instructors can help improve students’ self-beliefs are discussed.
The development of environmentally clean and energy-efficient coal-based power plants is of strategic importance to meet the increasing demand for more energy and clean air in the future. Carbon–air fuel cells (CAFCs) are a promising class of clean, efficient and sustainable power generators fueled by an abundant, cheap and sometimes renewable fuel source – coal, biomass, municipal waste, and other forms of solid carbons, with low emissions of CO2, NOx, SOx and VOCs. Because of the inherent thermodynamic and environmental advantages, CAFCs have garnered much interest in recent decades. In this article, we review recent advances in material development for catalysts/anodes and novel designs of various types of CAFCs. Fundamental understanding of the mechanisms and rate-limiting steps in carbon conversion is also discussed in detail. Finally, the review is concluded with promises and challenges of CAFCs.
LiNi0.5Mn1.5O4 as a 4.7V-class cathode material was prepared through the radiated polymer gel method that allowed homogeneous mixing of starting materials at the atomic scale. After calcinations of the polymer gels containing the metal salts at different temperatures from 750 to 1150°C, powders of a pure LiNi0.5Mn1.5O4 phase were obtained. X-ray diffraction and transmission electron microscopy were used to characterize the structures of the powders. Galvanostatic cell cycling and a simultaneous DC resistance measurement were performed on Li/LiNi0.5Mn1.5O4 cells. It is found that the powder calcined at 950°C shows the best electrochemical performance with the initial discharge capacity of 139mAhg−1 and 96% retention after 50 cycles. Adopting a slow cooling procedure for the powder calcination can increase the capacity of LiNi0.5Mn1.5O4 at the 4.7V plateau. Besides, a “w”-shape change of the DC resistance of Li/LiNi0.5Mn1.5O4 cells is a good indication of the structural change of LiNi0.5Mn1.5O4 electrode during charge and discharge courses.
A facile electrochemical route was applied to prepare polypyrrole (PPy)/anthraquinone sulfonate (AQS)/reduced graphene oxide (r-GO) composite. The as-synthesized composite showed an interconnected porous structure, which is related to the competitive relationship between two dopants. The cyclic voltammograms and electrochemical impedance spectra confirmed that the presence of highly conductive r-GO in PPy matrix ensured an efficient redox reaction obtained for redox-active AQS. As a result, the PPy/AQS/r-GO composite exhibited an enhanced specific capacity of 127.2 mAh g−1 with ca. 100% coulombic efficiency at 0.1 A g−1. Furthermore, the superior rate capability and cycling stability were also observed for PPy/AQS/r-GO, compared to AQS doped PPy. It is possible to adopt this co-dopants system for creating electro-active polymer materials with high capacities that are comparable to that of conventional inorganic intercalation electrode materials.
Although performance of LiS batteries with various carbon/sulfur composites has been wildly explored at room temperature, the reports studying the behaviors of LiS cathodes at low temperature are few. Herein, a novel multifunctional graphene oxide-Zn(II)-triazole complex (denoted as GO-Zn(II)-AmTZ) with excellent property at low temperature(-20 °C) is successfully prepared. In GO-Zn(II)-AmTZ, the metal ions (Zn(II)), amine groups and the N penta-heterocycle are introduced synchronously, leading improvement of LiS performance at both room and low temperature. As a result of the multifunctional arrangement, GO-Zn(II)-AmTZ cathodes could provide a discharge capacity of 315 mAh g−1 (0.5C) after 100 cycles at −20 °C. A capacity of ∼520 mAh g−1 is achieved over 300 cycles at room temperature with low capacity attenuation rate at current rate of 0.5C. The improved performance is speculated to the contribution of enhanced polysulfide immobilization of GO-Zn(II)-AmTZ modified by the Zn(II), amine groups and the N atoms.
The inherent electrochemical performance of supercapacitor electrodes is highly depends on their structures, therefore, numerous efforts are focus on rationally designing and constructing supercapacitor electrodes with hierarchical structures. In this work, we report a facile method for controllable synthesis of hierarchical shell-core structures by anchoring NiO nanospines on concave spherical carbon particles. It is observed that the inner carbon core, acting as a highly efficient current collector, is inherited from the calcination of concave spherical sulfonated polystyrene, while the external shell, resulting from these NiO nanospines, plays the role of active materials. Benefiting from the hierarchical shell-core structures with large specific surface area, additional electroactive sites, reduced interior space, short ions diffusion pathway and intimate electrode/electrolyte contacts, the as-synthesized electrodes exhibit superior electrochemical performance, such as high specific capacitance (1161 F g−1 at a current density of 2 A g−1), good rate capability (839 F g−1 at a high current density of 10 A g−1) as well as long cycling stability (92.4% retention after 3000 cycles at 2 A g−1). We believe that the electrodes are expected to be the most promising candidate for supercapacitors, and more importantly, this strategy plays an important role in the construction of novel hierarchical shell-core structures with superior electrochemical performance for advanced energy storage materials.
The enhancement of Ga incorporation into the CIGS thin film by electrodeposition has been realized. One-step electrodeposition Cu(In,Ga)Se2 thin films under different hydrogen peroxide (H2O2) concentrations was investigated. The ratio Ga/(In+Ga) and characteristics of thin films were further modulated by adding H2O2 into electrolyte. The mechanism of the effects of H2O2 on electrodeposition Cu(In,Ga)Se2 thin films was illustrated using a schematic diagram. And this mechanism was proved by cyclic voltammograms, potentiostatic polarization, energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and Raman spectra. The films were found to have the same basic chalcopyrite structure of CuInSe2, and have the widen band gap (UV-VIS-NIR spectrophotometer) after adding H2O2 into the electrolyte. The evidence of Ga incorporation increment can be observed from the peak shift of Raman spectra and widen band gap.
The solar insolation received on earth have different components in which power is embedded. Out of many, visible spectrum and thermal spectrum are separately used to harvest energy through solar thermal or solar photovoltaic systems respectively. Photovoltaic (PV) panels are reported to experience undesirably high temperature rise due to heat accumulation from solar radiation which is not actively converted into electricity. This undesirable heat decreases conversion efficiency of PV panels. Thermoelectric module (TEM) in coordination with PV panel is proposed to recover and convert this waste heat energy to useful electrical energy. This paper demonstrates the capability of proposed system for electrical power generation from waste heat developed in PV panel in addition to generation from PV systems. Dynamic model of photovoltaic thermoelectric hybrid (PTH) system is developed in SIMULINK/ MATLAB environment based on electrical and thermal characteristics of the material. Simulation results for maximum energy harvesting for PTH system are presented under dynamic perturbations in solar radiations. Proposed control scheme ensures maximum energy harvesting without allowing system to operate at temperature out of prescribed limits for PV or TEM. It has been observed in the simulation that PTH system effectively handles the load and source transitions, which validates the scheme.
Many commonly used measures of figural reproduction have been found to be relatively insensitive to the effects of right temporal lobe dysfunction. More positive findings are present in studies using measures of figural learning over repeated trials. This study examined the use of a commercially available measure of figural learning in a sample of epilepsy patients undergoing presurgical neuropsychological testing. The Brief Visuospatial Memory Test—Revised (BVMT-R) was administered to 47 subjects undergoing comprehensive presurgical workups with video and EEG monitoring. Groups with left (N=25) and right (N=22) temporal lobe seizures did not differ on BVMT-R measures of learning, delayed recall, or yes/no recognition. Approximately 29% of the sample exhibited “impaired” performance in comparison to published norms. The results of receiver operating curve analyses revealed little discrimination in performance between groups. The BVMT-R does not appear to have the sensitivity required for assessing nonverbal memory in this population.
Battery polarisation is not only responsible for reducing battery available capacity but also for controlling heat generation characteristics of batteries. This phenomenon was therefore carefully studied and modelled by Newman, Tiedemann and Gu (NTG). The NTG model is now widely used for simulating battery thermal behaviour and has even been adopted by CD-adapco for their proprietary battery modelling software - Battery Design Studio. The model however revolves around an idealised battery cell. It may thus not be applicable to commercial battery cells. This paper scrutinises the effect of open circuit voltage (OCV), a key parameter in the NTG model, on the irreversible heat generation of a commercial cell under a controlled environment by differentiating the OCV recorded immediately after the current stops flowing through the cell and the OCV corresponding to the equilibrium state of the cell. It is noticed that the NTG model underestimates the irreversible heat generation rates for a 20 Ah Li-ion pouch cell by approximately 0.15 W and 0.22 W for discharge currents at 0.33C and 0.5C at an operating temperature of 27 °C, respectively. It is also observed that the accuracy of the NTG model is significantly improved in simulating thermal behaviour of commercial battery cells when the OCV is representative of the cell equilibrium voltage.
Reduced graphene oxide (rGO) has attracted wide attention as anode materials of lithium ion batteries, however, restacking of rGO sheets limits its capacity and rate performance. To address this issue, a sandwich-like composite of N-doped carbon (NDC) and rGO (rGO@NDC) was fabricated via a process of absorbing [EMIm]N(CN)2 ionic liquid on the surface of graphene oxide (GO) nanosheets and subsequent heat-treating of the composite. The rGO@NDC composite exhibits a high specific capacity of 409.4 mAh g−1 with a Coulombic efficiency of 100% after 50 cycles at a charge-discharge rate of 0.5 C, and a specific capacity of 222.8 mAh g−1 with no capacity fade after 1200 cycles at charge-discharge rate of 10 C. Compositing the rGO with NDC particles can decrease the superficial oxygen-containing functional groups of the rGO, and therefore decrease side reactions during battery cycling. And embedding of NDC particles on the surface of rGO sheets avoids the restacking of rGO sheets and enlarges the interlayer space of the rGO to facilitate Li+ transport within the rGO@NDC. Finally, the NDC particles provide more accessible sites for Li+, and rGO sheets as conductivity networks improves electron transport.
The gas generation associated with the use of the lithium bis(oxalate)borate—(LiBoB) based electrolyte at the elevated temperature were detected in the pouch cell (MCMB/LiNi1/3Co1/3Mn1/3O2 with 10% excess Li), which might prevent the LiBoB usage as a salt. However, the cell capacity retention was improved significantly, from 87 to 96% at elevated temperature, when using LiBoB as an electrolyte additive. The capacity fade during cycling is discussed using dQ/dE, area specific impedance, and frequency response analysis results. Most of the capacity loss in the cell is associated with the rise in the cell impedance. Moreover, results from the differential scanning calorimetry indicate that the thermal stability of the negative electrode with the solid electrolyte interface (SEI) formed by the reduction of the LiBoB additive was greatly improved compared with that obtained from the reduction of LiPF6-based electrolyte without additive. In this case, the onset temperature of the breakdown of the LiBoB-based SEI is 150°C which is higher than that of the conventional electrolyte without additive. Furthermore, the total heat generated between 60 and 170°C is reduced from 213 to 70Jg−1 when using LiBoB as electrolyte additive compared to the one without additive. In addition, the thermal stability of the charged LiNi1/3Co1/3Mn1/3O2 with 10% excess Li was not affected when using LiBoB as an electrolyte additive.
Objective Interference with brain rhythms by noninvasive transcranial stimulation that uses weak transcranial alternating current may reveal itself to be a new tool for investigating cortical mechanisms currently unresolved. Here, we aim to extend transcranial direct current stimulation (tDCS) techniques to transcranial alternating current stimulation (tACS). Background Parameters such as electrode size and position were taken from those used in previous tDCS studies. Methods Motor evoked potentials (MEPs) revealed by transcranial magnetic stimulation (TMS), electroencephalogram (EEG)-power, and reaction times measured in a motor implicit learning task, were analyzed to detect changes in cortical excitability after 2-10 minutes of AC stimulation and sinusoidal DC stimulation (tSDCS) by using 1, 10, 15, 30, and 45 Hz and sham stimulation over the primary motor cortex in 50 healthy subjects (eight-16 subjects in each study). Results A significantly improved implicit motor learning was observed after 10 Hz AC stimulation only. No significant changes were observed in any of the analyzed frequency bands of EEG and with regard to the MEP amplitudes after AC or tSDCS stimulation. Similarly, if the anodal or cathodal DC stimulation was superimposed on 5, 10, and 15 Hz AC stimulation, the MEP amplitudes did not change significantly. Conclusions Transcranial application of weak AC current may appear to be a tool for basic and clinical research in diseases with altered EEG activity. However, its effect seems to be weaker than tDCS stimulation, at least in the present context of stimulus intensity and duration. Further studies are required to extend cautiously the safety range and uncover its influence on neuronal circuitries.
Publisher Summary This chapter provides an overview of the global plastics industry today and tomorrow. It indicates the orders of magnitude of global plastics consumption. It also shows the market shares by weight of the main thermoplastics versus total thermoplastics in the main industrialized countries. It presents schematically the approximate market shares consumed by different application sectors for plastics as a whole. The consumption of thermoplastics predominates but the market share distribution of the thermoplastic application sectors is nevertheless somewhat different from that of plastics as a whole. For each type of polymer, there are several possible processing methods from which it will be necessary to choose to best suit the required geometries, production rates, targeted properties and economic context. The study reports the consumption of the major thermoplastics in 2005 for the three main geographic areas, together with market shares and average annual growth rates (AAGR). These identified thermoplastics represent roughly 70% of the overall global consumption of plastics. Polymeric materials are intrinsically expensive, but their use becomes appealing if one takes into account the processing costs, the new technical possibilities that they permit and the total cost at the end of their lifetime.