batterydata/paper-abstracts huggingface dataset:
The exploration of cathode materials with high energy density has been considered as one key for the development of magnesium batteries. The high magnesium storage capacity of CuS has been demonstrated at high temperature (over 100 °C), but its electrochemical performance at lower temperature still needed to be improved largely. Herein, we realize the high magnesium storage activity (over 300 mAh g−1) of CuS cathode at room temperature via adjusting electrode-electrolyte interface. In the full magnesium battery, CuS cathode achieves a high capacity of 119 mAh g−1 after 30 cycles at 50 mA g−1. Besides, the conversion-type storage mechanism has been certified via ex-situ XRD and so on. This work demonstrated CuS is a promising cathode material for magnesium battery.
Although many studies have investigated the clinical importance of sleep apnea on rapid eye movement (REM) and non-REM (NREM) sleep, the relationship between behavioral performance and apneic events during different sleep phases remains unclear. In the present study, we sought to investigate the effect of sleep phase fragmentation due to sleep-disordered breathing (SDB) during REM and NREM on the vigilance and sustainability of attention based on psychomotor vigilance task (PVT) performance.
The thermal mechanics of Lithium-ion (Li-ion) batteries is explored with a focus on thermal swelling. Experiments show for the first time that the swelling shape of prismatic battery cells due to temperature variations is significantly different from that due to Li-ion intercalation in unconstrained conditions. In contrast to uniform and orthotropic Li-ion intercalation swelling in a direction perpendicular to electrodes, the nonuniform temperature distribution in the jellyroll and the gaps/voids between electrodes result in distinguishable different swelling shapes. A unique coupled thermal-structural analysis with a simple, but efficient 3-D finite numerical model is proposed to investigate the impact of temperature variations on the thermal behaviors of battery cells. Anisotropic heat conduction and temperature dependency of the coefficient of thermal expansion are taken into account and found to have an impact on temperature distribution and thermal expansion. Experimental validation of the proposed model clearly demonstrates that the coupled thermal-structural analysis with the proposed model can predict accurately the thermal swelling at unconstrained conditions. The solution at pack (constrained) conditions shows that the nonuniform temperature distribution of the jellyroll still plays a critical role for the thermal swelling shape, although the gaps/voids do not occur because of the constraints from spacers in the pack, suggesting that the estimation of core temperature is important. Such an accurate model, able to estimate cell thermal behavior, is beneficial to the design of Li-ion batteries, development of stress or strain sensors, optimum sensor placement, and thermal management of not only single battery cells but also battery packs.
A series of LiNi0.5Mn0.5− x Co x O2 (0≤ x ≤0.5) compounds was prepared by a solid state reaction, and their structural, morphological and electrochemical characteristics were also investigated. Co doping suppresses the formation of the impurity phase, NiO, and improves the crystallinity of the compounds. Moreover, the unequilavent substitution of cobalt for manganese would give rise to the increase in the average valence of nickel, thereby shrinkage in the lattice volume and improvement of the electrochemical properties. LiNi0.5Mn0.2Co0.3O2 shows a high reversible capacity as well as an excellent rate capability in 3–4.6V.
A novel material of Si/TiO2 nanowire array (TNA) composite has been designed and fabricated, to be used as anode material for lithium ion batteries. Firstly, Self-assembled and well-aligned rutile TiO2 nanowire arrays are synthesized on pretreated titanium substrate by solvothermal route. Subsequently, Si film is introduced into the interspace of the nanowires, forming a Si/TNA composite. The field-emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM) images indicate that the dimension of TiO2 nanowires is 10 ± 2 nm wide. The TEM and Raman results reveal that Si contains amorphous and nanocrystalline phases. The composite with 75% Si content owns the best electrochemical performance, the first charge capacity reaches as high as 1480 mA h g−1, and remains at 802.3 mA h g−1 after 200 cycles.
A key area of weakness in individuals with fetal alcohol spectrum disorder (FASD) is working memory, thus the goal of this study was to determine whether teaching children (aged 4–11) with FASD verbal rehearsal would increase their memory. Rehearsal training has been effective in other populations with working memory difficulties, so we hypothesized that children with FASD would also benefit from rehearsal training. Children were divided into an Experimental group, who received rehearsal training and a Control group, who did not receive training. All children were tested on digit span tasks over three sessions: a pretest (baseline) and then post-test 1 and post-test 2 (where only the Experimental group received rehearsal training). The Experimental group showed a significant increase in performance across session but the Control group did not. Children in the Experimental group performed significantly higher than the Control group on post-test 2 but not on the pretest or post-test 1. More children in the Experimental group showed behavioral evidence and self-report of rehearsal after training. Rehearsal training was successful at increasing the memory for numbers among children with FASD and may help to ameliorate working memory difficulties in FASD, ultimately supporting academic and developmental growth of children with FASD.
Tuning the structure, morphology, and electronic state is of great significance to achieve highly efficient hydrogen evolution reaction (HER) electrocatalysts. In this work, we originally develop a silk-cocoon structured S-rich cobalt polysulfide (CoSx, x ≈ 3.9) catalyst with extremely high HER activity through a facile hydrothermal process. The formation mechanism of the silk-cocoon structured CoSx has been systematically studied and the key factors in the formation of this structure are discussed. Such a nanostructured catalyst has hollow spheres that are interwoven by numerous sub-10 nm nanofibers to form into a three-dimensional conductive network by connection of micrometer long nanofibers. The silk-cocoon structured CoSx shows excellent HER activity with an onset potential of 0 V vs. a reversible hydrogen electrode and a Tafel slope of 41 mV dec−1. The activity is much higher than that of the reported metal sulfide materials and is even comparable to commercial Pt/C. Moreover, the overpotential to yield a current density of 10 mA cm−2 is only 42 mV. We ascribe the high HER activity to the S-rich sites and the conductive silk-cocoon structure, which can benefit the charge transfer of the material. Thus, this work provides a guiding strategy for synthesis of nanostructured transition metal polysulfides with enhanced HER catalytic performance.
The effect of fluorination on the surface of an AB2-type hydrogen-storage alloy with the composition Zr0.7Ti0.3V0.4Mn0.4Ni1.2 is investigated. Electron probe microanalysis (EPMA), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), and X-ray diffraction (XRD) techniques show that the fluorinated AB2-type alloys have a unique surface morphology and high reactivity with a protective film. The treatment is found to be effective when lanthanum is incorporated in the alloy. The cycle-life of the metal hydride (MH) electrode increases significantly as a result of a decrease in the overpotential by electrode polarization. The degradation rate of the MH electrode is less than 3% after 100 cycles when lanthanum is added at 1–3wt.%.
The requirement for energy density of lithium-ion batteries becomes more urgent due to the rising demand for driving range of electric vehicles in recent years. Meanwhile, the performance stability of batteries with high energy densities tends to deteriorate, leading to accelerating degradation and safety issues. As a result, it is critical to explore the reasons that yield the sudden degradation and to recognize the degradation knee point of Nickel-Cobalt-Manganese batteries commonly used for electric vehicles. Existing results have disclosed that the lithium deposition of negative electrode dominates the sudden degradation of battery capacity. This paper extracts key parameters that characterize the aging status to facilitate knee point recognition in engineering practice. Furthermore, a novel method that integrates quantile regression and Monte Carlo simulation method to identify the accelerated fading knee point is introduced. The dynamic safety boundary determination method for the whole battery lifetime is proposed to update and monitor the safety zone. It is verified by experiments that the recognition results of capacity degradation knee point appear within 90–95% capacity range at 25 °C, 35 °C and 45 °C conditions, which can provide an early warning before the battery fails. Using the proposed method for recognizing the sudden degradation of capacity, recognition result is effective even if the input is disturbed and has strong reliability and stability under different conditions. It is helpful to promote the sustainable and stable development of the electric vehicles and improve advanced applied energy technologies.
The evolution of wireless technologies has led to the need to provide network support for data and video applications and thus foster the development of new types of network configurations. MANET is an important type of network operation that employs mechanisms that can enable a dynamic self-configuration to challenge the routing protocols. These protocols can also be challenged because energy failures are becoming more serious than the common network failures; in addition, the quality of the multimedia stream corresponds to a type of data flow that is increasingly prevalent in today's network. In light of this, a new cross-layer routing mechanism is set out to make an improvement in the main routing protocols. This involves adding decision metrics to all the network layers in a fuzzy-based mechanism with QoS and QoE guarantees, mobility indexes and energy parameters, by choosing the best path with an efficient way to use energy. The proposal has been evaluated in a network simulator which demonstrates the efficiency of increasing energy awareness and maximizing the life time of the network.
The sub-micrometer lead powders were electrodeposited on a mild steel (MS) substrate in PbS-containing (10–50 mM) choline chloride–urea deep eutectic solvent (ChCl–urea DES) at 353 K and 2.5 V. The electrochemical behaviors of the Pb(II)/Pb on MS and glass carbon electrodes were determined by cyclic voltammetry and chronoamperometry measurement. It indicates that the reduction of Pb(II) is a quasi-reversible process. The increase in PbS concentration effectively promotes the EPb(II)/Pb shift in positive direction which can facilitate the reduction of Pb(II). The initial nucleation stage of metallic lead on MS electrode is a three-dimensional instantaneous nucleation for diffusion control and the diffusion coefficient of Pb(II) at 353 K is about 2.40 × 10−7 cm2/s. The three-dimensional sub-micrometer lead particles are agglomerated together and composed of many overlapped lead flakes about 150–200 nm. Moreover, the XRD results reveal that metallic lead can be deposited with a face-centered-cubic structure and the strongest peak intensity is (111) plane. This finding provides a theoretical guidance for the one-step preparation of sub-micrometer lead powders using galena concentrate as raw material by an eco-friendly and facile electrochemical approach in close neutral electrolyte, which can efficiently shorten the production flow and realize the integration of metallurgy and material processes.
Hazard perception in driving involves a number of different processes. This paper reports the development of two measures designed to separate these processes. A Hazard Perception Test was developed to measure how quickly drivers could anticipate hazards overall, incorporating detection, trajectory prediction, and hazard classification judgements. A Hazard Change Detection Task was developed to measure how quickly drivers can detect a hazard in a static image regardless of whether they consider it hazardous or not. For the Hazard Perception Test, young novices were slower than mid-age experienced drivers, consistent with differences in crash risk, and test performance correlated with scores in pre-existing Hazard Perception Tests. For drivers aged 65 and over, scores on the Hazard Perception Test declined with age and correlated with both contrast sensitivity and a Useful Field of View measure. For the Hazard Change Detection Task, novices responded quicker than the experienced drivers, contrary to crash risk trends, and test performance did not correlate with measures of overall hazard perception. However for drivers aged 65 and over, test performance declined with age and correlated with both hazard perception and Useful Field of View. Overall we concluded that there was support for the validity of the Hazard Perception Test for all ages but the Hazard Change Detection Task might only be appropriate for use with older drivers.
Two novel nanocrystalline materials, hexagonal TiOF2 (hTiOF2, space group R 3 ¯ c hexagonal) nanocubes and LiTiOF2 (space group R3c hexagonal), were prepared by a one-step solvothermal method and the lithiation of hTiOF2 precursor, respectively. All the products have been characterized by means of X-ray diffraction, thermogravimetry, scanning electron microscopy, transmission electron microscope and high resolution transmission electron microscope. Furthermore, Rietveld analysis has been used to evaluate the structure of LiTiOF2. The electrochemical properties were evaluated using the products as cathode for half-cells in lithium-ion batteries (LIBs). It is confirmed that hTiOF2 and LiTiOF2 have the same frame and the Li intercalation/de-intercalation mechanism of hTiOF2 is discussed. An electrochemical activation process is confirmed in the charge-discharge cycles of hTiOF2 half-cells. The hTiOF2 half-cell after activation delivered a high specific capacity of 200mAh g−1 at 1C in the range of 3.0–0.8V and maintained a specific capacity of 120mAhg−1 at 20C over 1000 cycles, which is a very satisfying performance.
Nuisance caused by odors is one of the most important problems for waste management plants. To control an odor nuisance, it must first be qu antified. The analytical difficulties in odor measurements are related to the high number of volatile components (belonging to several chemical classes), above all when the concentration is lower than the detection limit of the technique used for the measurement. In this work, 2-butanone, α-pinene, tetrachloroethylene, dimethyldisulfide, β-pinene, limonene, phenol and benzoic acid are determined, because they are representative of some important classes of compounds with higher odor impact. The compounds are sampled with thermal desorbable radial diffusive samplers Radiello® containing Tenax cartridges. The analytical repeatability and the complete thermal desorption of the cartridges were verified for each odor compound; the relative standard deviations for repeated samples and the recovery percentage were, respectively, less than 7% and about 97% for all compounds. The measurements of the linearity of sampling showed no systematic difference according to the collection period. The comparison between the odor threshold and the limit of detection demonstrated that this method is reliable for the recognition and quantification of odor compounds, allowing Public Administration to impose legal limits and the control agencies to verify them.
In order to improve the high-rate capacity and cycleability, the graphene-like structured MoS2 is successfully coated on Li1.2Mn0.54Ni0.13Co0.13O2 via wet chemical method followed by a solid state reaction. Transmission electron microscopy and energy dispersive X-ray spectrometry indicate that the surface of cathode particles is uniformly covered with a crystalline MoS2 layer (∼5nm thick) after 3wt% MoS2 surface coating. Compared with the bare sample, MoS2-coated electrode exhibits the improved Coulombic efficiency, cycleability and rate capability in the voltage range of 2.0–4.8V, even at elevated temperature. Based on the analysis from cyclic voltammetry and electrochemical impedance spectra, the remarkably improved electrochemical performances of the surface-modified electrode are ascribed to the presence of lithium-active MoS2 coating with the layered structure, which could not only suppress the undesirable side reaction and increasing impedance, and enhance the structural stability of host material, but also provide the additional sites for insertion of extracted lithium to compensate the lost Li sites during the activation of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 to effectively increase the initial Coulombic efficiency.
Material properties such as high surface area, pore size distribution, variable oxidation states and good electronic conductivity are the basis for charge storage application of carbons, polymers, metal oxides and sulfides. Recently, transition metal sulfides, NiCo2S4 in particular, are in the forefront as electrode materials for energy storage devices. Here we show that a composite material of NiCo2S4 with nitrogen doped mesoporous carbon (NMC) can improve the capacitance and cyclic stability to a large extent. For this purpose we fabricated NiCo2S4 and NiCo2S4@NMC heterostructures on nickel foam employing hydrothermal method. This method allows us to directly obtain binder free electrodes for electrochemical studies. The composite materials are characterized by XRD, BET, Raman spectroscopy, SEM, HRTEM, and XPS. The electrochemical activity of these materials is investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and impedance spectroscopy (EIS). The NiCo2S4@NMC composite shows unique nanoball architecture with higher surface area (42 m2 g−1) as compared to NiCo2S4 (11 m2 g−1). This composite material shows highest capacitance value of 2017 F g−1 at 3 A g−1 compared to NiCo2S4, and excellent cyclic stability retaining 88% capacitance after 5000 cycles. The performance of NiCo2S4@NMC composite material is attributed to the conductivity of nitrogen doped mesoporous carbon network and the material porosity for easy accessibility of electrolyte ions supported by Ni foam substrate.
For large scale batteries, sulfur is an attractive cathode active material for lithium batteries because of high theoretical capacity of 1675mAhg−1. However, severe capacity fading and low conductivity of sulfur are significant challenges for its practical application. Here, we report a facile approach to prepare reduced graphene oxide nanoscroll embedded with well-dispersed sulfur (S/GNSC) through a one-pot oxidation of sulfide and reduction of graphene oxide followed by freeze-casting process to generate graphene nanoscroll. The S/GNSC takes the novel shape of reduced graphene oxide sheet spirally wrapped into one-dimensional tubular structure, which enhances electrochemical performance by acting as physical barrier to prevent polysulfide from dissolving and an effective network to promote electron and Li+ transport during reaction. Therefore, the S/GNSC composite with high sulfur loading of 76wt% exhibits high initial capacity of 1295mAhg−1 and reversible capacity of 744mAhg−1 after the 100th cycle at 0.2C when it is used as a cathode material for lithium-sulfur battery, while the capacity of sulfur loaded on reduced graphene oxide sheet (S/rGO) is continuously fading to 510mAhg−1 after the 100th cycle due to the irreversible loss of polysulfide.
This paper considers some control design problems in a power system driven by battery/supercapacitor hybrid energy storage devices. The currents in the battery and the supercapacitor are actively controlled by two bidirectional buck–boost converters. Two control objectives are addressed in this paper: one is to achieve robust tracking of two reference variables, the battery current and the load voltage, the other is to achieve smooth transition of these variables during load switch. Based on the state-space averaged model we newly developed, the control design problems are converted into numerically efficient optimization problems with linear matrix inequality (LMI) constraints. An experimental system is constructed to validate the control design methods.
A simple mathematical model is established to predict the self-discharge process in a kilowatt-class vanadium redox flow battery stack. The model uses basic mass transport theory to simulate the transfer of vanadium ions in the battery. The simulation results agree reasonably with the experimental values, confirming the validity of the model. It is found that the diffusion rate of vanadium ions depends on the diffusion coefficient, the partition coefficient and the concentration gradient of the vanadium ions between the two half cells. For the self-discharge process at the initial SOC of 0, the net transfer direction of vanadium ions is towards the negative electrolyte until the diffusion flux of V3+ becomes larger than that of VO2+. For the self-discharge process at the initial SOC of 65%, the net transfer direction of vanadium ions is towards the positive electrolyte at the initial 20h and then turns to the negative electrolyte. There are two obvious changes in the diffusion flux of vanadium ions at about 33h and 43h, corresponding to the vanishing time of VO2 + and V2+ respectively.
A self-assembled Manganese (Mn) based metal organic complex (Mn-MOC) with spherical structure was synthesized via a solvothermal reaction. The Mn-MOC precursor materials were converted to hierarchical porous Mn3O4/C nanospheres through thermal annealing treatment. These nanospheres exhibited a high reversible specific capacity (1237 mAh/g at 200 mA/g), excellent ratability (425 mAh/g at 4 A/g), and extremely long cycle life (no significant capacity fading after 3000 cycles at 4A/g) as an anode in lithium ion batteries. The notable capability for lithium storage is attributed to the unique porous hierarchical structure of the Mn3O4/C nanospheres, which consist of homogeneously distributed Mn3O4 nanocrystals with thin carbon shells. Such a desired nanostructure not only provided large reaction surface area and enhanced electrical conductivity, but also promoted the formation of a stable solid electrolyte interphase (SEI) and accommodated the volume change of the conversion reaction type electrode.
Nanostructured hybrids constituted by transition metal sulfides and graphene are promising for next-generation energy storage devices. Herein, we rationally design and prepare iron-nickel sulfide particles uniformly distributed on reduced graphene oxide (FeNiS/rGO) via a hydrothermal approach, followed by thermal treatment in the presence of sulfur powders. Benefiting from integrated structures of electro-active FeNiS particles and conductive graphene backbones, the FeNiS/rGO electrodes exhibit a high specific capacitance of 2454 F g−1 at 1 A g−1 and a good lithium storage capacity of 998 mAh g−1 at 0.2 A g−1, as well as outstanding capacity retention with increasing current densities and stable cycling performance. An asymmetric supercapacitor, assembled by FeNiS/rGO as the positive electrode and activated carbon as the negative electrode, delivers a high energy density of 64.3 Wh kg−1 at a power density of 508 W kg−1.