batterydata/paper-abstracts huggingface dataset:
The development of advanced 1D/2D hierarchical nanocomposites for high-performance lithium-ion batteries is important and promising. Herein, monodispersed FeCO3 nanorods anchored on reduced graphene oxide (RGO) are prepared via a facile and efficient one-pot hydrothermal synthesis. The influence of RGO content on the morphology and electrochemical performances of the mesoporous FeCO3/reduced graphene oxide (FeCO3/RGO) composites are systematically studied. Optimized FeCO3/RGO composite shows good cycling stability. It delivers an initial discharge capacity of 1449 mAh·g−1 at the current density of 200 mA g−1 and maintained a capacity of 789 mAh·g−1 after 80 cycles. A moderate amount of RGO sheets can not only provide more conductive channels to improve the electrode conductivity, but also effectively buffer the large volume variation of FeCO3 during continuous charge/discharge process. The combination of FeCO3 nanorods with RGOs synergistically contribute to enhanced capacity and durability of the composite anode. It demonstrates that RGO anchored-FeCO3 nanorods should be an attractive candidate as anode material for high-performance lithium-ion batteries.
A series of novel hierarchical NiCo2O4@Ni4.5Co4.5S8 composites grown on nickel foam are synthesized via a two-step electrodepositon process with a post-annealing procedure. The firstly-grown vertical NiCo2O4 nanosheet arrays serve as skeleton for the subsequent growth of horizontally Ni4.5Co4.5S8 nanosheets, generating abundant active sites for speedy redox reactions. As a supercapacitor material, NiCo2O4@Ni4.5Co4.5S8-4 demonstrates a high specific discharge capacity of 369 mA h g−1 at 1 A g−1, a superior rate capability of displaying 258 mA h g−1 at 20 A g−1 and an ideal cycling stability of merely 4.8% capacity loss after 5,000 cycles. The kinetic analysis is performed to qualitatively confirm the charge storage mechanism, manifesting that capacitive effect is dominant in the total capacity. In addition, the assembled NiCo2O4@Ni4.5Co4.5S8-4//activated carbon aqueous hybrid supercapacitor device exhibits a superior specific energy (124.77 Wh kg−1 at 1.08 kW kg−1) and specific power (39.29 Wh kg−1 at 15.21 kW kg−1). The self-discharge analysis reveals that it takes more than 26 h for the voltage to drop to 0.75 V. 83.56% of initial capacity is maintained after 5,000 cycles at 100 mV s−1, verifying the satisfactory stability. Therefore, the outstanding electrochemical property enables NiCo2O4@Ni4.5Co4.5S8-4 composite to become a potential electrode material for practical applications.
The conventional enhancement in capacitive performance that only relies on electrode materials is limited. Here, based on the system-level design principle, we explore the possibility of enhancing capacitance through both electrode and electrolyte. A novel and ultrahigh-performance asymmetric supercapacitor has been fabricated using two redox electrode systems. The positive electrode system consists of graphene supported Co(OH)2 nanosheet (Co(OH)2/GNS) electrode and mixed KOH and K3Fe(CN)6 aqueous electrolyte. And the negative electrode system comprises carbon fiber paper supported activated carbon (AC/CFP) electrode in mixed KOH and p-phenylenediamine (PPD) aqueous electrolyte. The novel asymmetric supercapacitor exhibits a significantly improved capacitive performance (specific capacitance of 204.5 Fg−1, operational voltage of 2.0V) in comparison with that of the conventional asymmetric supercapacitor (66.8 Fg−1, 1.5V) fabricated without redox electrolyte. The improvement is attributed high reversibility and conductivity of electrode materials and redox electrolyte, as well as the synergistic effect between the two electrode systems, resulting in a ultrahigh energy density (114.5 Whkg−1 at a power density of 1000 Wkg−1), excellent power density (4000 Wkg−1 at an energy density of 31.6 Whkg−1) and long-term cycling stability (after 20000 cycles, initial capacitance remains well). These encouraging results afford a facile and efficient way to fabricate ultrahigh-performance supercapacitors for the increasing demands on the energy storage devices.
A Fe2O3 nanoparticle/carbon aerogel composite (Fe2O3/CA) is prepared from a carbon aerogel prepared by a sol–gel process by a simple soaking in a Fe(NO3)3 solution and subsequent heat treatment at 600°C. Thermal gravimetric analysis, X-ray diffraction, scanning and transmission electron microscopy, energy dispersive X-ray analysis and X-ray photoelectron spectroscopy are used to characterize the products. The electrochemical performance of samples with different Fe2O3 content is evaluated. The optimal sample Fe2O3/CA-60 exhibits a good capacity retention of 916 and 617mAhg−1 for the 1st and 100th cycle, respectively, which is much better than that of pure Fe2O3 and CA. The improved cycling performance, specific capacity and rate capability of Fe2O3/CA is mainly attributed to the synergistic effects of the nanoporous network skeleton of CA and the uniformly dispersed Fe2O3 nanoparticles.
Digitalization has yet to arrive in the field of clinical neuropsychology. Arguments both in favor and against have been frequently seen in scientific publications. The purpose of this article is to compare a digital version of the Trail Making Test (TMT), a common assessment tool of a clinical neuropsychologist, to a conventional paper version. An empirical study was conducted with a counterbalanced within-subject design. Voluntary participants (n = 53) conducted two different versions (paper, tablet) of TMT in the library of medical sciences of the University of Helsinki. Significant differences in completion times between TMT variants were observed in TMT part A (F(1 , 106.591) = 7.661, p = .008). No significant differences were found from part B (F(1 , 60.397) = .980, p = .327). Results of this study are in favor of further research of the digitalized version of TMT. This study indicates that it is possible and fruitful to digitalize traditional neuropsychological methods.
d-Cycloserine (DCS) has been shown to enhance memory and, in a previous trial, once-weekly DCS improved negative symptoms in schizophrenia subjects. We hypothesized that DCS combined with a cognitive remediation (CR) program would improve memory of a practiced auditory discrimination task and that gains would generalize to performance on unpracticed cognitive tasks. Stable, medicated adult schizophrenia outpatients participated in the Brain Fitness CR program 3–5 times per week for 8weeks. Subjects were randomly assigned to once-weekly adjunctive treatment with DCS (50mg) or placebo administered before the first session each week. Primary outcomes were performance on an auditory discrimination task, the MATRICS cognitive battery composite score and the Scale for the Assessment of Negative Symptoms (SANS) total score. 36 subjects received study drug and 32 completed the trial (average number of CR sessions=26.1). Performance on the practiced auditory discrimination task significantly improved in the DCS group compared to the placebo group. DCS was also associated with significantly greater negative symptom improvement for subjects symptomatic at baseline (SANS score ≥20). However, improvement on the MATRICS battery was observed only in the placebo group. Considered with previous results, these findings suggest that DCS augments CR and alleviates negative symptoms in schizophrenia patients. However, further work is needed to evaluate whether CR gains achieved with DCS can generalize to other unpracticed cognitive tasks.
Recent years have seen significant growth of electric vehicles and extensive development of energy storage technologies. This Review evaluates the potential of a series of promising batteries and hydrogen fuel cells in their deployment in automotive electrification.
Transition metal oxides have recently aroused a renewed and increasing interest as conversion anode materials for sodium ion batteries. Being their electrochemical performances strongly dependent on morphological aspects, has been here proposed a straightforward approach to modulate morphological characteristics of a transition metal oxide (Co3O4) using a low cost synthetic route. The as obtained optimized morphology allows the realization of high practical specific capacities, higher than 500 mAh g−1 after 50 cycles, and represents a valid candidate for further optimization. In addition to the morphology-performance correlations, the reaction mechanism beyond the electrochemical behavior was also investigated revealing the role of the CoO phase in the charge/discharge process. Finally, an electrode pre-sodiation treatment for conversion materials is presented: it has been indeed demonstrated that it sensibly decreases the irreversible capacity correlated to the first cycle and improves cycle ability.
Metal-air batteries are one of the most promising electrochemical systems for energy storage and conversion. Herein we report promising results by exploiting manganese dioxide nanoparticles as ORR electrocatalysts. MnO2 nanorods were prepared through a hydrothermal synthesis, i.e. by varying both the salt precursors (i.e. manganese sulphate or chloride) and the oxidizing agents (i.e. ammonium persulfate or potassium permanganate). All the nanopowders were finely characterized on structural, morphological and surface points of view. Then, their electrocatalytic power was tested either in aqueous 0.1M potassium hydroxide or in Tetra Ethylene Glycol Dimethyl Ether (TEGDME)/LiNO3 0.5M electrolytes, by using Gas Diffusion Electrodes (GDEs) and Glassy Carbon (GC) as cathodes, respectively. All the nanoparticles promoted the ORR by causing a shift of the onset potential up to 100mV in both solvents. Nevertheless, this shift was different according to the solvent/electrolyte used: in the case of the ether-based solvent, different values are obtained by adopting the synthesized MnO2 powders. Thus, we hypothesized that the structural/surface properties of MnO2 samples are leveled in the aqueous medium (i.e. in a OH rich solvent, the hydroxyls can interact with the homologs on the MnO2 surface), contrary to what occurs in the organic solvent. Furthermore, a different behavior was observed also on the kinetic point of view thus leading to diverse interpretations of the oxygen reduction mechanism, especially in TEGDME.
In a high-risk community sample, we examined the role of regulative temperament and emotionality as well as the extent of gender specificity in the development of externalizing problems. 151 boys and 157 girls born at differing degrees of obstetric and psychosocial risk were followed from birth into adolescence. In infancy and childhood, NYLS-derived temperamental characteristics were assessed by a highly structured parent interview and standardized behavioral observations. At age 15 years, externalizing problems were measured by the Child Behavior Checklist. As revealed by multiple linear regression and logistic regression, low regulative abilities predicted adolescent behavioral and attentional problems over and above obstetric and psychosocial risks. Gender specificity was found in the strength of the association rather than in the kind with a stronger long-term prediction from infant and toddler temperament in girls. Compared to regulative abilities, temperament factors describing aspects of mood and fear/withdrawal versus approach tendencies played a minor role in the development of externalizing problems. Findings are discussed in terms of gender-specific risk factors and possible differential developmental trajectories to subtypes of disruptive behavior.
Drawing in aphasia therapy has been used predominately as a substitution for speech or to augment communication when other modalities are non-functional. The value of drawing as a route for facilitating verbal expression has not been a focus of prior research. We compared the usefulness of drawing and writing as compensatory strategies for improving naming in individuals with aphasia. Activation patterns of writing and drawing in healthy adults were examined using fMRI. Clinical results suggest that drawing facilitated naming whereas writing diminished accurate naming responses, and that drawing quality is not relevant to this facilitatory effect. Functional MRI findings revealed strong bi-hemispheric activation of semantic and phonological networks while drawing that may support our clinical findings.
A modified ball-milling-assisted green solid reaction method is provided to prepare Li4Ti5O12/C composite materials with controllable carbon content. Thermal analysis was utilized to investigate the reaction process and the temperature for eliminating carbon. The added carbon and the time for eliminating the carbon can affect the particle size and greatly improve the cycling stability and rate performance. Besides, the particle size can reach ~60 nm, the Li4Ti5O12 eliminated carbon at 600 °C has ~178% higher discharge capacity than that without added carbon after 500 cycles under the same conditions. As for the Li4Ti5O12 with a carbon weight of 10.6%, the second discharge capacity can reach 177.2 and 120.8 mAh g−1 at 1 and 20 C rates, respectively. Its discharge capacity still remains at  118.3 mAh g−1 after 500 cycles under various current rates. The results are comparable to those of the reported Li4Ti5O12/PAS composite.
A groundwater recharge investigation in the arid zone of Australia is presented. The investigation used a wide range of hydrogeological techniques including geological mapping, surface and borehole geophysics, groundwater hydraulics, streambed temperature and pressure monitoring, and hydrogeochemical and environmental tracer sampling, and it was complemented by analysis of rainfall intensity from 18 tipping-bucked rain gauges, climate data and stream runoff measurements. Run-off and recharge from a 200-mm rainfall event in January 2015, the largest daily rainfall in the local 50-year record, were investigated in detail. While this major storm provided substantial run-off as a potential source for focused, indirect recharge, it only produced enough actual recharge to the shallow aquifer to temporarily halt a long-term groundwater recession. A series of smaller rainfall-runoff events in 2016 produced a similar recharge response. The results suggest that the total magnitude of a flood event is not the main control on indirect groundwater recharge at this location. A deeper aquifer shows no hydraulic response to surface-water flow events and is isolated from the shallow system, consistent with its Pleistocene groundwater age. This supports a growing body of evidence indicating that attributing or predicting generalised changes in recharge to changes in climate in dryland environments should not be attempted without first unravelling the dynamic processes governing groundwater recharge in the locality of interest. The results should prompt more detailed and long-term field investigation in other arid zone locations to further understand the episodic and nonlinear nature of recharge in such environments.
We investigate the sputtering deposition as a tool for preparing Polymer Electrolyte Membrane Fuel Cell (PEMFC) electrodes with improved performance and catalyst utilization. Anodes of PEMFC with ultra-low loading of Pt (0.05mgcm−2) are developed by alternate sputtering of Pt and painting layers of carbon nanotube ink with Nafion directly on the gas diffusion layer. Sputter depositing alternate layers of Pt on carbon-Nafion layer (CNL) has increased the anode activity over single-layer Pt deposited anode due to improved porosity and the presence of Pt nanoparticles in the inner CNL. Also, we investigated the influence of Nafion content in the CNL. The optimal Nafion content giving less resistance and better performance in an anode is 29wt.%. This is significantly lower than for standard MEA anodes, indicating sufficient interfacial contact between each CNL. We studied the anodes prepared with 50wt.% Nafion, which revealed larger ohmic resistance and also, blocks the CNL pores reducing gas permeability. Excellent mass transfer and performance is obtained with three-layer Pt sputter deposited anode with CNL containing 29wt.% of Nafion.
A Zn-air battery is a potential next-generation energy storage device owing to its extremely high theoretical energy density. Currently, it is important to explore non-precious metal electrocatalysts with high electroactivity and stability in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for the development of Zn-air batteries. In this work, porous (Ni,Co)Se2 nanosheets were synthesized by selenizing NiCo2O4 nanosheets. By regulating the conductivity and morphology of the sample, the prepared porous (Ni,Co)Se2 nanosheets show enhanced electrocatalytic activity for OER and ORR compared to NiCo2O4 nanosheets. The aqueous Zn-air battery using porous (Ni,Co)Se2 nanosheets as the air cathode exhibits superior charge and discharge performance (1.98 V for charging and 1.17 V for discharging), high specific capacity (770 mAh/g), and excellent cycle stability (140 h). These results indicate that the porous (Ni,Co)Se2 nanosheets are suitable as a bifunctional electrocatalyst for future Zn-air batteries.
A new gel polymer electrolyte (GPE) based on ethyl cellulose/poly(vinylidene fluoride) (EC/PVDF) blended polymer was prepared by immersion precipitation phase inversion. The structure of the porous membrane was controlled by the addition of EC. The performance of the membranes with different ratios of EC to PVDF were characterized by X-ray diffraction spectroscopy (XRD), scan electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), linear sweep voltammetry (LSV), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). The results show that as the ratio of EC to PVDF rose to 3:7 (wt.%), the membrane presented the best thermal stability. The ionic conductivity of this GPE was 1.33 mS cm−1, which was much higher than the PVDF membrane (0.69 mS cm−1) at room temperature. The electrochemical window of this GPE was established to be as high as 5.25 V (vs. Li/Li+). The Li/LiNi0.5Mn1.5O4 coin cell with this GPE displays excellent cyclic stability and rate performance at room temperature compared to PVDF membrane. This suggests that the self-supporting EC/PVDF blended GPE has a high potential for 5 V high-voltage lithium-ion batteries (LIBs).
Publisher Summary The transmission electron microscope (TEM) is widely used for characterizing the microstructure of materials, and there are several imaging modes that are sensitive to magnetic microstructure. Electron holography is an alternative TEM technique that provides access to the phase and amplitude of an electron wave after it has traversed through the sample. This chapter describes the development of electron holography and the basic principles of the technique with particular reference to magnetic imaging. Some applications of electron holography are discussed in the chapter, which include the studies of hard magnets, magnetic media, and magnetic microstructures. The chapter also discusses prospects for the further development of the technique, such as real-time viewing of dynamic events and the in situ application of variable external fields. Off-axis electron holography offers the prospect of direct visualization and quantification of magnetic fields with high spatial resolution and sensitivity. The theoretical framework of the technique is well established, and experimental applications to important materials problems are presented in the chapter.
In an attempt to enhance the energy storage capacity and discharge voltage, a new cathode material based on ferrocene and LiF for lithium-ion batteries has been explored [Fe/LiF/C] nanocomposite (1) has been synthesized by pyrolysis of a ferrocene/LiF mixture at 700°C using a rotating quartz tube setup in a furnace. The structure and morphology of the composite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Brunauer–Emmer–Teller (BET) analysis, Raman, and Mössbauer spectroscopy. The nanocomposite is composed of well-defined nanotubes which are interlinked by graphitic shell-type structures containing uniformly distribution of Fe, Fe–C, and LiF nanoparticles. The binder-free nanocomposite cathode showed enhanced electrochemical performance with the reversible specific capacity of 230mAhg−1 (1.3–4.3V) at 20.8mAg−1 at room temperature. It exhibited a remarkable cyclic stability and good rate capability performances. The morphology of 1 was changed by ball milling, and the resulting nanocomposite 2 did not show any cyclic stability as a cathode. Thus, the cyclic stability and rate capability performances of 1 were attributed to its structure and morphology.
An overview of the availability and affordability of energy sources and generation potential in Brazil is given in the present manuscript. Most of the information given here up-to-now was only accessible to Portuguese speakers, such as found in governmental plans for the energy sector. Brazilian public strategy for the following years concentrates on the promotion of more efficient energy utilization in different sectors of the society and also on diversifying its energy matrix. A perspective of programs, projects and technologies available in the country is also given. It is known that the Brazilian energy matrix is largely dominated by hydroelectric power, which relies on a consolidated infrastructure. However, recently discovered pre-salt layer of oil and natural gas presents new technological and scientific challenges for the professionals in the sector. National development and solidification of technologies for harnessing energy from the abundantly available biomass is yet another challenging task for Brazil. This manuscript not only presents the current Brazilian energy scenario and perspectives but also intends to identify some opportunities for investment and research, especially in the areas of materials science and engineering. A vision for what is expected for the Brazilian energy matrix based on current governmental actions and future technology is given in this perspective, while maintaining a critical overview on how to achieve optimum results with a balanced economic and environmental approach.
For reliable and safe operation of lithium-ion batteries in electric or hybrid vehicles, diagnosis of the cell degradation is necessary. This can be achieved by monitoring the increase of the internal resistance of the battery cells over the whole lifetime of the battery. In this paper, a method to identify the internal resistance in a hybrid vehicle is presented. Therefore, a special purpose model deduced from an equivalent circuit is developed. This model contains parameters depending on the degradation of the battery cell. To achieve the required robustness and stable results under these conditions, the method uses specific signal intervals occurring during normal operation of the battery in a hybrid vehicle. This identification signal has a defined timespan and occurs regularly. The identification is done on vehicle measurement data of terminal cell voltage and current collected with a usual vehicle sampling rate. Using the adapted internal resistance value in the model, a degradation index is calculated by compensating other influences, e.g. battery temperature. This task is the main challenge, as the impact of the temperature on the resistance, for example, is one order of magnitude higher than the influence of the degradation for the investigated lithium-ion cell. The developed estimation and monitoring method is validated with measurement data from single cells and shows good results and very low computational effort.