batterydata/paper-abstracts huggingface dataset:
The reliability and safety of lithium-ion batteries can be affected by overheating issues. Phase change materials like paraffin due to their large heat capacities are among the best solutions for the thermal management of batteries. In this investigation, multiscale modelling techniques were developed to explore the efficiency in the thermal management of rechargeable batteries through employing the paraffin composite structures. A combined atomistic-continuum multiscale modelling was conducted to evaluate the thermal conductivity of paraffin reinforced with graphene or hexagonal boron-nitride nanosheet additives. In addition, heat generation during a battery service was simulated using the Newman's electrochemical model. Finally, three-dimensional heat transfer models were constructed to investigate the effectiveness of various paraffin composite structures in the thermal management of a battery system. Interestingly, it was found that the thermal conductivity of paraffin nanocomposites can be enhanced by several times but that does not yield significant improvement in the batteries thermal management over the pure paraffin. The acquired findings can be useful not only for the modelling of nanocomposites but more importantly for the improvement of phase change materials design to enhance the thermal management of rechargeable batteries and other electronic devices.
Lithium cobalt oxides are used as a cathode material in batteries for mobile devices, but their high theoretical capacity has not yet been realized. Here, the authors present a doping method to enhance diffusion of Li ions as well as to stabilize structures during cycling, leading to impressive electrochemical performance.
The layered Ni-rich oxide LiNi0.8Co0.1Mn0.1O2 cathode has been significantly attractive due to its large reversible capacity (∼200mAhg−1). However, the inherent poor cycling stability of the Ni-based cathode materials is always a serious issue for restricting its commercialization. In this paper, we introduced Li2MnO3 as an electrochemical inactive component in Ni-rich oxide LiNi0.8Co0.1Mn0.1O2 to stabilize its structure. The modified LiNi0.8Co0.1Mn0.1O2 composites with low-content Li2MnO3 were prepared by a solid-state reaction process. The results from XRD structure refinement and SAED confirm that Li2MnO3 phase exists homogeneously in the composites. The modified LiNi0.8Co0.1Mn0.1O2 composites with inactive Li2MnO3 show much better cycling stability and stable average discharge voltage compared with the pristine one when charged to 4.5V. Especially, the modified LiNi0.8Co0.1Mn0.1O2 composite with 10% Li2MnO3 (LNCMO-1090) delivers a reversible capacity of 207mAhg−1 and keeps 155mAhg−1 after 100 cycles at 20mAg−1 (0.1C), corresponding to a capacity retention of 75%, while LiNi0.8Co0.1Mn0.1O2 could only maintain a capacity of 128mAhg−1 with a capacity retention of 59% after 100 cycles. The improved cycling performance of the Li2MnO3-containing electrode could be attributed to the stabilized effect of Li2MnO3 on the electrode surface structure, as evidenced by the lower charge-transfer resistance.
Incorporating renewable energy into a grid still poses a challenge, that can only be tackled with precise measurement and control. Transferring power from producer to consumer as locally as possible in order to maximize efficiency requires measurement and control functions to be present on the low-voltage grid level. This can only be achieved by massively interconnected, ICT-enhanced sensors and actuators. Interconnecting the former, in turn exposes the grid to various threats from cyberattacks. This creates the need for a holistic, structured and comprehensive approach to engineering a low-voltage smart grid architecture that allocates its resources in such a way that cyber security is preserved. While known previous work either lacks a risk-based approach, comprehensiveness or best practices, this article provides a smart grid-specific methodology that combines risk assessment and threat modeling to generate a holistic set of security requirements. Furthermore, it presents best practices to secure an archetypal smart low-voltage grid architecture based on a concrete example. It considers threats on the architectural, protocol, and device level, while also considering environmental constraints to assure security using mainly state-of-the-art mitigation measures.
In this study, the effect of Zn doping on the electrochemical properties of P2-Na2/3[Mn1−xZnx]O2 (x = 0.0, 0.1, 0.2, 0.3) is investigated for the first time. The P2-Na2/3[Mn0.7Zn0.3]O2 electrode deliveres a specific discharge capacity of approximately 190 mAh g−1 based on the oxygen-redox reaction (O2−/O1−), after which the Mn4+/Mn3+ redox reaction contributes to the capacity. The cycling performance of the P2-Na2/3[Mn0.7Zn0.3]O2 electrode is also greatly enhanced compared with that of the P2-Na2/3MnO2 electrode (capacity retention of 80% vs. 30% after 200 cycles). This improved cyclability is due to the suppression of cooperative Jahn–Teller distortion as well as stabilization of the structure by the electrochemically inactive Zn2+ ions. First-principle calculations and experimental analysis, including X-ray photoelectron spectroscopy and X-ray absorption near edge structure spectroscopy, clearly confirms that the Zn2+ substitution in P2-Na2/3MnO2 enables the O2−/O1− redox reaction. In addition, time-of-flight secondary ion mass spectroscopy analysis reveals that no sodium carbonates forms on the electrode surface. Our findings provide a potential new path to utilize cost-effective Mn-rich cathode materials for sodium-ion batteries via not only cationic redox but also anodic redox.
The growth and nucleation mechanism of poly(ortho-ethoxyaniline) (POEA) are investigated by cyclic voltammetry (CV) and potentiostatic technique. It was shown that growing of POEA is faster in sulphuric acid solution compared to phosphoric acid solution. Different rate trends were obtained with the increase of switching potential. From cyclic voltammograms, it is evident that the obtained polymer has a similar behaviour to the one reported for polyaniline, but there is a difference in position of current peaks, due to the electronic and steric effects of ethoxy-group. In presence of different anions, a different nucleation mechanism was obtained. In sulphuric acid solution nucleation proceeds through 3D instantaneous nucleation under diffusion control, and in phosphoric acid solution nucleation proceeds through 3D progressive nucleation under diffusion control.
Spherical LiNi0.75Co0.25O2 compounds were synthesized by sintering spherical Ni0.75Co0.25(OH)2 and LiOH·H2O precursors at various temperatures in an oxygen atmosphere. A pure phase LiNi0.75Co0.25O2 could be identified. SEM observation showed that the LiNi0.75Co0.25O2 particles are spherical in shape and are composed of many small crystals. Magnetic susceptibility measurements reveal that the spherical LiNi0.75Co0.25O2 compounds have a more ordered layered structure than that of non-spherical LiNi0.75Co0.25O2. The spherical LiNi0.75Co0.25O2 cathodes demonstrated a stable electrochemical performance in lithium-ion cells with a high reversible capacity of 167mAh/g and good cyclability.
Thin films of Sn–Cu alloys with various compositions were prepared by annealing tin-coated copper foils at 463K for 0–45h. Their charge–discharge behaviors as negative electrodes for sodium secondary batteries were investigated using an inorganic ionic liquid electrolyte, i.e., NaFSA–KFSA (FSA=bis(fluorosulfonyl)amide), at 363K. A Sn–Cu film annealed for 4h exhibited a stable reversible capacity of approximately 100 mAh (g-Sn)−1. The improvement in the cyclability is discussed based on X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy results.
The current strong interest in ionic liquids is motivated by their unique combination of properties such as negligible vapour pressure, thermal stability, non-flammability, high ionic conductivity and wide electrochemical stability window. The first part of this short review deals with all the specific aspects of sol-gel in the presence of ionic liquid, which can act as drying control chemical additive, catalyst, porogenous agent and solvent or co-solvent. The second part is devoted to the properties of the gels in which the ionic liquid is kept confined (ionogels) and their applications as electrolyte membranes, optical devices, catalysts and sensors.
Nurturing an emerging industry’s business ecosystem always requires stakeholders’ efforts and role transformation. By systematically reviewing and studying the evolution of the Chinese electric vehicle industry, this paper constructs a three-dimensional theoretical framework including stages of business ecosystem lifecycle, stakeholder classification and functional roles, to analyse the transformation both of different stakeholders and their functional roles. The findings show that business ecosystem stakeholders have experienced role transformation following a mechanism defined as the ‘Triple Oscillation’ Model during the evolution of the emerging industry. These findings also help develop a conceptual model of agent-based system for business ecosystem evolution, which could be a starting point for further emerging industry study.
CuO was used to modify the surface of Li[Ni0.5Co0.2Mn0.3]O2 cathode material. The structure and electrochemical properties of the CuO-coated Li[Ni0.5Co0.2Mn0.3]O2 were investigated using X-ray diffraction, scanning electron microscope, and charge/discharge tests. The results showed that the CuO coated Li[Ni0.5Co0.2Mn0.3]O2 cathode exhibited an improved rate capability at room and elevated temperature at high rates. The 2.0wt.% CuO coated sample had the capacity retention of higher than 89%, and high capacity of 179.7mAhg−1 at 5C, in comparison with the capacity retention of 60% and capacity of 161.5mAhg−1 for the pristine one at elevated temperature. The cyclic voltammograms and impedance spectra results revealed that the CuO coating reduced the polarization and improved the electrochemical activity of cathode. Thus the CuO-coated Li[Ni0.5Co0.2Mn0.3]O2 shows a potential lithium ion batteries for high power applications.
Tea consumption has traditionally been associated with mental benefits, often ascribed to caffeine and L-theanine. Research to date suggests that tea improves attention. However, findings subtly differ for tea as a whole and for caffeine or L-theanine. Specifically, tea was found to improve simple attention processes, involving arousal and psychomotor activity, similar to the effects of caffeine. However, tea also improved more complex attention processes (e.g. Switch task performance), by allowing subjects to be more focused on the task at hand. In contrast, caffeine has been shown to affect complex attention performance, but only when consumed in doses higher than those regularly consumed in tea. While behavioral effects of L-theanine are largely absent, caffeine and L-theanine consumed together may exert different effects from those obtained from caffeine alone. Moreover, tea not only improves attention performance but also feelings of alertness. In summary, tea and tea ingredients can improve attention.
The SNARC (Spatial-Numerical Association of Response Codes) effect (i.e., a tendency to associate small/large magnitude numbers with the left/right hand side) is prevalent across the whole lifespan. Because the ability to relate numbers to space has been viewed as a cornerstone in the development of mathematical skills, the relationship between the SNARC effect and math skills has been frequently examined. The results remain largely inconsistent. Studies testing groups of people with very low or very high skill levels in math sometimes found relationships between SNARC and math skills. So far, however, studies testing such extreme math skills level groups were mostly investigating the SNARC effect in individuals revealing math difficulties. Groups with above average math skills remain understudied, especially in regard to children. Here, we investigate the SNARC effect in gifted children, as compared to normally developing children (overall n = 165). Frequentist and Bayesian analysis suggested that the groups did not differ from each other in the SNARC effect. These results are the first to provide evidence for the SNARC effect in a relatively large sample of gifted (and mathematically highly skilled) children. In sum, our study provides another piece of evidence for no direct link between the SNARC effect and mathematical ability in childhood.
In this study, a flexible hybrid film based on single-wall carbon nanotubes (SWNTs) was fabricated. The SWNTs@MnO2/Polypyrrole (PPy) film was used as a supercapacitor electrode without binders to achieve high capacitance. The binder-free electrode with SWNT and PPy layers improved the conductivity of the electrode materials, as well as the ion diffusion rate and charge-transfer resistance, thus achieving excellent electrochemical performance compared with SWNTs@MnO2 electrodes. The specific capacity was 351Fg−1 based on the total weight of the electrodes with energy density of 39.7Whkg−1 and power density of 10kWkg−1. Our study could provide a novel and facile strategy for the development of high-performance energy storage devices.
Practical applications of lithium-sulfur batteries require not only high specific capacities and long cycle life but also high rate performance. Herein, a layered carbide derived carbon (CDC) with hierarchically porous structure is designed and used as sulfur host for high rate lithium-sulfur batteries for the first time. In the layered CDC, sulfur was mainly infiltrated into the micropores and small mesopores, which could efficiently confine sulfur species and suppress polysulfides shuttling. At the same time, the layered structure and large mesopores would further shorten ion diffusion distance and buffer volume expansion. As a result, the layered CDC/sulfur composite with a sulfur loading of 50wt.% delivered not only a high initial discharge capacity of 1229 mAh g⿿1 at 0.5C, but also a superior reversible capacity of 621 mAh g⿿1 at 5C. Especially, the high rate capability could also be achieved even at a higher sulfur loading (68wt.%). This work suggests that porous carbon combined with layered structure and hierarchical pores could be used as effective matrix to host sulfur for high rate lithium-sulfur batteries.
This article provides an overview of the design, fabrication and characterization of the most widely used cathode buffer layers (CBLs) constructed using pristine zinc oxide (ZnO), doped-ZnO, and ZnO-based composites as well as the surface modified ZnO-based CBLs for the improvement of power conversion efficiency (PCE) and long-term device stability of inverted polymer solar cells (PSCs). To achieve high PCE in inverted PSCs, the selection of an appropriate material to form high quality CBLs so as to optimize the electron collection and transport is particularly important. ZnO has been the most extensively studied material for CBL of inverted PSCs in view of its relatively high electron mobility, optical transparency, ease of being synthesized with low cost solution methods at low temperature, versatile morphologies, and being environmentally stable. It is pointed out in this review that the electronic processes at the interface between the ZnO CBL and polymer active layer play an important role in determining the solar cells performance. This review attempts to deliver better understanding with regard of the impacts of (1) morphology, (2) thickness, (3) nanostructures, (4) doping, (5) surface modification and (6) composition/hybrids of ZnO CBLs on the inverted PSCs performance. Well understanding the interfacial processes in PSCs is believed also a benefit to the emerging perovskite solar cells in view of their similar energy levels and device structures.
We characterized 30-month longitudinal change in functional activation and connectivity during working memory in premanifest (pre-HD) and symptomatic (symp-HD) Huntington’s disease (HD). In a case–control longitudinal study (baseline, 18 months, and 30 months), we compared change in fMRI activity over time during working memory in 22 pre-HD, 11 symp-HD, and 20 control participants. Outcome measures were BOLD (blood-oxygen-level-dependent) activity during 1-BACK and 2-BACK working memory and functional connectivity between dorsolateral prefrontal cortex (DLPFC) and caudate. Compared with controls, the pre-HD group showed significantly increased activation longitudinally during 1-BACK in the left DLPFC and medial frontal cortex, and further increased activation during 2-BACK in the bilateral caudate, putamen, and temporal cortex. Longitudinal change in symp-HD was not significantly different from controls. Longitudinal changes in pre-HD were associated with disease burden and years to onset. The pre-HD group showed longitudinal decreased functional connectivity between left DLPFC and caudate during both 1-BACK and 2-BACK performance. We provide an evidence for longitudinal changes in BOLD activity during working memory prior to clinical manifestations of HD. The ability to increase activation in the prefrontal cortex over time may represent an early compensatory response during the premanifest stage, which may reflect an early marker for clinically relevant functional changes in HD.
No approved treatment is available for patients with vascular cognitive impairment (VCI) due to cerebral small vessel disease (SVD).
Vehicle-to-Grid (V2G) is a promising technology that allows the batteries of idle or parked electric vehicles (EVs) to operate as distributed resources, which can store or release energy at appropriate times, resulting in a bidirectional exchange of power between the ac grid and the dc EV batteries. This bidirectional exchange of power is realized using bidirectional power electronic converters that connect the grid with the EV battery. Most research on bidirectional converters for V2G applications focuses on using two dedicated power conversion stages – a bidirectional ac-dc conversion stage that helps in power factor correction, followed by a bidirectional dc-dc conversion stage that provides voltage matching. However, a single bidirectional ac-dc conversion stage can also facilitate V2G and grid-to vehicle (G2V) active power transfers. This paper reviews and compares the various bidirectional ac-dc and dc-dc converter topologies that facilitate V2G and G2V active power flows. Moreover, the paper discusses the various classes of charger/discharger systems reported for V2G applications, like on-board/off-board, integrated/non-integrated and conductive/inductive, and a comparative statement is made based on certain proposed criteria. Further, the current trends in the application of wide band-gap devices in high power-dense V2G capable converters and integration of renewable energy sources into EV charging/discharging infrastructures have also been discussed.
For heat capacity measurement of ceramic materials at high temperatures above 1500K, two new calorimeters, i.e. a high speed cooling calorimeter and an advanced-direct heating pulse calorimeter, have been developed in our laboratory. The high speed cooling calorimeter is assembled of an induction heating furnace, a paraboloidal mirror and a high speed six-wavelength pyrometer. In this calorimeter, the heat capacity is determined from the cooling rate of a sample dropped from the induction heating furnace. As a simulation of a dropped specimen, two different experiments on transient modes were made using a calibrated tungsten lamp in the temperature range 2060–2180K: (1) by changing temperature with time (cooling curve measurement), and (2) by changing the position of a tungsten lamp vertically at constant temperature. Both results show reliability of this calorimeter at high temperatures. The advanced direct heating pulse calorimeter is a re-designed and re-constructed apparatus of the direct heating pulse calorimeter previously developed in our laboratory to increase the measuring temperature for the heat capacity up to 2000K. By the improvement of a new vacuum vessel, molybdenum thermal insulator and tantalum heating wire, heat capacity and electrical conductivity of graphite could be measured up to 1750K.
LiAlO2-surface modified LiMn1.58Ni0.42O4 spinel cathode materials have been prepared by coating Al2O3 on Mn0.79Ni0.21CO3 precursors, followed by post-sintering with Li2CO3 at 900 °C. X-ray diffraction and FT-IR analyses indicate that during the calcination process aluminum ions not only react with Li2CO3 to form a strengthened LiAlO2 coating layer but also migrate from the surface into the spherical particles. The LiAlO2-surface modified LiMn1.58Ni0.42O4 samples exhibit excellent electrochemical performance compared to that of the bare one in terms of rate capability and cyclability. In particular, the 1 mol.% LiAlO2-surface modified sample can deliver a discharge capacity of 100.6 m Ah g−1 even at a high current density of 4 C-rate, while the bare one only has a discharge capacity of 49.5 m Ah g−1. At 55 °C, the 1 mol.% LiAlO2-surface modified LiMn1.58Ni0.42O4 sample shows outstanding cyclability with less than 5% capacity fade after 150 cycles. Based on these results, coating on the precursors to prepare a strengthened LiAlO2 coating layer would be a promising method to enhance the electrochemical performance of 5 V spinel cathode materials.
Electrochemical behavior of zinc and thin polyaniline (PANI) electrodes in citrate/chloride-contained electrolyte has been investigated by the means of electrolyte composition optimization. Electrolyte contained 0.8 M sodium citrate, 0.3 M ammonium chloride, and ~0.3 M zinc chloride has been found to be an optimum electrolyte for the further applications in the real zinc–polyaniline citrate/chloride-based secondary cell.
A flower-like Fe3O4/carbon nanocomposite with nano/micro hierarchical structure is prepared by controlled thermal decomposition of the iron alkoxide precursor, which is obtained via an ethylene glycol-mediated solvothermal reaction of FeCl3 and hexamethylenetetramine (HMT) in the absence of any surfactant. The nanocomposite is characterized by the assembly of porous nanoflakes consisting of Fe3O4 nanoparticles and amorphous carbon that is in situ generated from the organic components of alkoxide precursor. When used as the anode materials for the lithium-ion batteries, the resultant nanocomposite shows high capacity and good cycle stability (1030mAhg−1 at a current density of 0.2C up to 150 cycles), as well as enhanced rate capability. The excellent electrochemical performance can be attributed to the high structural stability and high rate of ionic/electronic conduction arising from the synergetic effect of the unique nano/micro hierarchical structure and conductive carbon coating.
We successfully observed the synchrotron-radiation-based Mössbauer absorption spectra with 158Gd and 99Ru. Their nuclear resonant energies were 79.5 keV and 89.6 keV, respectively, and they are factually the highest energy which energy region synchrotron radiation covers with sufficient intensity as the incident X-rays for Mössbauer spectroscopy. Although the low recoilless fraction owing to these high resonant energy, Mössbauer energy spectra of GdPd3 to 158Gd2O3 and fcc-Ru nanoparticles to bulk hcp-99Ru metal were obtained with natural samples of the former compounds with sufficient amount, because of the high transparency of these high energy X-rays(to electronic scattering). In spite of large statistical errors, we can evaluate the hyperfine parameters when the spectrum includes simple 1-site profile. 99Ru and 158Gd SR-based Mössbauer absorption spectra of various complex materials including somewhat complex structures will be available with the improvements to the measurement system; More detector elements for larger solid angle subtended to the scatterer sample will yields more counting rates and improvement higher recoilless fraction by arranging more appropriate chemical specimen as the scatterer yields deeper absorption profile.