batterydata/paper-abstracts huggingface dataset:
In this paper, we report a novel Sn/G/RGO-S battery with high capacity and good cycle life in comparison to conventional lithium-ion batteries. Low cost electroplating and drop cast method are developed for the first time to prepare binder free highly porous 3D Sn/G/RGO composite on carbon paper substrate as anode. The unique 3D porous network of Sn/G composite allows better accommodation of volume expansion induced by Li insertion, while presence of graphene in the co-electrodeposited Sn/G composite provides enhanced electron conduction. Additional coating of RGO on the surface of co-electrodeposited Sn/G composite protects the electrode surface from the direct electrolyte contact, and minimizes the progressive SEI formation during repeated charge-discharge cycles. Consequently, Sn/G/RGO electrode in half-cell exhibits a much superior electrochemical performance and better cycle life. We also demonstrate a full-cell by using S/C as cathode and Sn/G/RGO composite with a very thin lithium foil on the surface as anode in order to avoid serious safety issues allied with lithium metal. Sn/G/RGO-S full cell delivers a high discharge capacity of 413mAhg−1 at the end of 40 cycles. The cell delivers a specific energy of about 660 Wh kg−1 based on the weight of sulfur and 336 wh kg−1 based on the total mass of the S/C electrode. The simple designed and cost effective technique to fabricate high performance Sn/G/RGO-S battery would be feasible for alternative clean energy sources.
Zn-Al-CO3 layer double hydroxides (LDHs) are synthesized by a simple hydrothermal method, followed by the anion-exchange processes to intercalate dodecyl sulfate (DS) anions into LDHs interlayer. The structures and morphologies of the as-prepared samples are characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results illustrate all samples have typical layer structure of LDHs, and the LDHs intercalated with dodecyl sulfate (LDH-DS) has better crystallization and smoother surface compares to conventional LDHs. Subsequently, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel and galvanostatic charge/discharge tests on LDH-DS electrode are performed. The results demonstrate that the exchanged sample has superior electrochemical performances in comparison with LDH-CO3, such as superior cycle stability, higher specific discharge capacity and utilization ratio of the active material. The specific discharge capacity of the LDH-DS electrode reaches 375mAhg−1 and exhibits excellent stability after 150 cycles.
Evidence is presented concerning the effect of surfaces on the segmental motion of PEO-based polymer electrolytes in lithium batteries. For dry systems with no moisture the effect of surfaces of nanoparticle fillers is to inhibit the segmental motion and to reduce the lithium ion transport. These effects also occur at the surfaces in composite electrodes that contain considerable quantities of carbon black nanoparticles for electronic connection. The problem of reduced polymer mobility is compounded by the generation of salt concentration gradients within the composite electrode. Highly concentrated polymer electrolytes have reduced transport properties due to the increased ionic cross-linking. Combined with the interfacial interactions this leads to the generation of low mobility electrolyte layers within the electrode and to loss of capacity and power capability. It is shown that even with planar lithium metal electrodes the concentration gradients can significantly impact the interfacial impedance. The interfacial impedance of lithium/PEO–LiTFSI cells varies depending upon the time elapsed since current was turned off after polarization. The behavior is consistent with relaxation of the salt concentration gradients and indicates that a portion of the interfacial impedance usually attributed to the SEI layer is due to concentrated salt solutions next to the electrode surfaces that are very resistive. These resistive layers may undergo actual phase changes in a non-uniform manner and the possible role of the reduced mobility polymer layers in dendrite initiation and growth is also explored. It is concluded that PEO and ethylene oxide-based polymers are less than ideal with respect to this interfacial behavior.
Abstract—The paper analyzes the Russian scientific and technological capabilities to manufacture a space-borne observation platform for high-precision monitoring of the Earth’s gravitational field. It is shown that some Russian space systems manufacturing technologies may well be used for this purpose; however, in general, the level of the domestic technologies must be substantially improved so as to meet stringent requirements of such a project. Nevertheless, it can be confidently stated that it is quite feasible to carry out this project using Russian technologies.
Background Cognitive deficits are a core feature in schizophrenia. Cognitive deficits appear to be present at the onset of schizophrenia and persist after remission of psychotic symptoms. As cognitive deficits are associated with poor functional outcome, they form an important focus of treatment. There are relatively few head-to-head comparisons of the effects of second generation antipsychotics on cognition in recent onset schizophrenia. This is the first study to compare the effects of a short term treatment of olanzapine versus ziprasidone on cognitive functioning in recent onset schizophrenia. An earlier study conducted in chronic patients revealed an enhancement of cognition after treatment for both agents, but the extent of improvement was not significantly different between ziprasidone and olanzapine. Method Patients with recent onset schizophrenia with limited previous exposure to medical treatment underwent a double blind randomized controlled treatment trial. Fifty-six patients completed the neuropsychological testing procedure prior to randomization and after eight weeks of treatment and were included in the analysis. We tested cognitive functioning in general and verbal memory in particular. We calculated a single unweighted composite score based on nine cognitive tests to determine general cognitive functioning. Results Cognition appeared enhanced after treatment, but was not significantly different between treatment groups, neither for the verbal memory measures, nor for the neurocognitive composite score. Furthermore, cognitive enhancement did not correlate to clinical improvement. Conclusion Cognitive deficits are not a reason for preferentially prescribing one of the two second generation antipsychotics tested over the other.
The CeO2/C hybrid coated LiMnPO4 composites are prepared via a simple and effective wet chemical process followed by heat treatment at 550 °C. The nanometer-sized CeO2 acts as an interconnector in carbon network, and its influence on the electrochemical performance is investigated in detail. The 0.25 wt.% CeO2-modified LiMnPO4/C (sample-0.25) exhibits the highest discharge capacity and the best cycle life, which can deliver an initial capacity of 139.9 mAh g−1 at 0.1C and still retain a reversible capacity of 120.4 mAh g−1 after 50 cycles (capacity retention of 86.1%). While for pristine LiMnPO4/C (sample-0), only 94.4 mAh g−1 can be obtained at the 50th cycle, corresponding to 72.9% of its initial discharge capacity (129.5 mAh g−1). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) results confirm that an integrated and hybrid CeO2/C coating layer is formed on LiMnPO4 surface and its existence has no influence on the structure of LiMnPO4. The reason for the improved electrochemical properties of the CeO2-modified LiMnPO4/C composites has also been studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements.
Highly porous nitrogen doped carbon fibers like churros morphology are prepared from a simple and cost-effective fabrication process, electrospinning with bicomponent polymer consisting of polystyrene (PS) and polyacrylonitrile (PAN). From appropriate ratio of two polymer and pyrolysis at 1100 °C, newly churros morphology with extremely high surface area (1271 m2 g−1) is prepared. During carbonization, more unstable PS than PAN plays a critical role in forming such morphology by acting as sacrifice materials, thus providing additional formation of inner pores and outer etched surfaces. Furthermore, it demonstrates excellent electrocatalytic activity toward ORR, which is attributed to highly meso- and macro porous nitrogen-doped large surface area and enhanced graphitic-nitrogen groups of carbon fibers. For example, the performance of a Zn–air cell based on the nitrogen-doped porous carbon nanofibers exhibits a peak power density of 194 mW cm−2, comparable to that based on a commercial Pt/C catalyst (192 mW cm−2). Further, the generation of hydrogen peroxide ions (<20%) in a half cell is similar to that on the commercial Pt/C catalyst.
The migration of intrinsic ions (e.g., MA+, Pb2+, I−) in organic–inorganic hybrid perovskites has received significant attention with respect to the critical roles of these ions in the hysteresis and degradation in perovskite solar cells (PSCs). Here, we demonstrate that extrinsic ions (e.g., Li+, H+, Na+), when used in the contact layers in PSCs, can migrate across the perovskite layer and strongly impact PSC operation. In a TiO2/perovskite/spiro-OMeTAD-based PSC, Li+-ion migration from spiro-OMeTAD to the perovskite and TiO2 layer is illustrated by time-of-flight secondary-ion mass spectrometry. The movement of Li+ ions in PSCs plays an important role in modulating the solar cell performance, tuning TiO2 carrier-extraction properties, and affecting hysteresis in PSCs. The influence of Li+-ion migration was investigated using time-resolved photoluminescence, Kelvin probe force microscopy, and external quantum efficiency spectra. Other extrinsic ions such as H+ and Na+ also show a clear impact on the performance and hysteresis in PSCs. Understanding the impacts of extrinsic ions in perovskite-based devices could lead to new material and device designs to further advance perovskite technology for various applications.
Heat treatment of highly crystalline graphite TIMREX® SLX50 at temperatures above 1200°C in an inert gas atmosphere resulted in a significant increase of the irreversible capacity, which is observed during the first electrochemical lithium insertion using a 1M LiPF6 ethylene carbonate/dimethyl carbonate 1:1 (w/w) electrolyte mixture. An additional potential plateau could be observed at about 0.45V versus Li/Li+ during the galvanostatic insertion of lithium into these heat-treated graphite materials. Post-mortem scanning electron microscope studies of negative electrodes containing such heat-treated graphite materials indicated the exfoliation of the graphite structure as reason for the additional potential plateau and the significant increase of the irreversible capacity in the first electrochemical lithium insertion. The graphite exfoliation during the first electrochemical lithium insertion disappeared when the heat-treated graphite materials were aged in a humid air atmosphere at room temperature for several months. This aging process turned out to be reversible. When regenerating the aged graphite material in a dry flux of argon gas at room temperature, the electrochemical graphite exfoliation could be observed again. Structure characterization of the graphite materials by X-ray diffraction (XRD) as well as surface investigations using Raman spectroscopy and gas adsorption measurements indicated that the exfoliation tendency of polycrystalline, highly crystallized graphite in ethylene carbonate containing electrolytes is controlled neither by the rhombohedral stacking faults in the graphite structure, the surface defects, nor by the superficial disordered carbon but only by the surface group chemistry. The amount of acidic surface oxide groups especially seems to be the key factor that influences graphite exfoliation during electrochemical lithium insertion in ethylene carbonate containing electrolytes.
We report a simple method to prepare hierarchical structures of carbon-coated Fe3O4 nanoparticles decorated on conductive multi-walled carbon nanotubes (CNTs) backbone as advanced anode materials for lithium ion batteries. The CNTs backbone serves as a shape template and conducting network to facilitate electron and lithium ion transport, while the carbon coating acts as a buffering layer to maintain the structural integrity of the electrode upon cycling. The prepared CNT@Fe3O4-C hybrid nanocables electrode exhibits excellent electrochemical performance with long-term cycling stability and high specific capacity of ∼1080mAhg−1 after 700 cycles at a current density of 500mAg−1, and good rate capability, which could be attributed to their unique structural features as well as the improved mechanical stability enabled by the outer carbon coating layer.
Polymers are used in commercial and proposed electrochromic devices as everything from the electrochromic materials themselves to solution thickeners, the matrix or solid phase of gels, solid polymer electrolytes and sealants. Each type of application of polymers in electrochromics is discussed and several definitions are compared with regard to gels and solution-based electrochromic redox systems. A review of electrochromics and polymer gels, especially from the perspective of the extensive patent literature on the subject, is given.
Producing hydrogen peroxide (H2O2) by electrochemical O2 reduction is a promising process, although developing high-performance carbon-based electrocatalysts at a low-cost with high-volume production remains a great challenge. We report a novel method to prepare the excellent electrocatalysts for the H2O2 production derived from the fungal hyphae (with bioconcentrated dye), which was used as the main sources of C, N, O, and P. The optimizational electrocatalyst had a large surface area with many nanopores, which exhibited excellent activity, selectivity, and stability towards O2 reduction when producing H2O2 in an alkaline media and good activity, selectivity, and stability in neutral media. A flow cell with the optimizational electrocatalyst as cathode and IrO2 as anode exhibited exceptionally high Faradaic efficiency, H2O2 productivity, and energetic efficiency in alkaline media. This maintained the Faradaic efficiency and H2O2 productivity when driven by commercial dry battery (1.5 V) or by solar-energy battery (2.5 V or 3.0 V). This is helpful in developing an electrocatalyst for H2O2 production and practical industrial application of O2 reduction to H2O2 by electrocatalysis. This low-cost, simple, and readily scalable approach offers insight for developing a novel electrocatalyst for other electrochemical reactions, such as hydrogen evolution reactions, oxygen evolution reactions, and CO2 reduction reactions.
We have shown that crown ether complexes with the lithium salt, lithium bis-(trifluoromethanesulphonyl) imide (LiTFSI), are plastic crystals as evidenced by DSC and their mechanical properties. The conductivity of the complexes was measured and found to vary as a function of crown ether:salt molar ratio. Our study of the (18-Crown-6)–LiTFSI (1/1) solid complex showed that it has a high conductivity reaching ∼10−4 Scm−1 at 50°C and an electrochemical stability of over 4V enabling its use in a lithium-metal battery. A lithium battery with 1:1 (18-Crown-6)–LiTFSI as electrolyte was assembled, tested, and found to exhibit reversible Li+ transport.
Patients with left hemisphere (LH) or right hemisphere (RH) brain injury due to stroke were tested on a speeded, color discrimination task in which two factors were manipulated: (1) the categorical relationship between the target and the distracters and (2) the visual field in which the target was presented. Similar to controls, the RH patients were faster in detecting targets in the right visual field when the target and distracters had different color names compared to when their names were the same. This effect was absent in the LH patients, consistent with the hypothesis that injury to the left hemisphere handicaps the automatic activation of lexical codes. Moreover, the LH patients showed a reversed effect, such that the advantage of different target–distracter names was now evident for targets in the left visual field. This reversal may suggest a reorganization of the color lexicon in the right hemisphere following left hemisphere brain injury and/or the unmasking of a heightened right hemisphere sensitivity to color categories.
Titanium alloys in orthopaedic implants are susceptible to mechanical disruption of the passive film (fretting corrosion). To study this effect, open-circuit potential (ocp) measurements before, during and after mechanical disruption of the passive film in a tribo-electrochemical cell on commercial pure titanium and Ti6Al4V alloy in inorganic buffer solutions in the pH range from 2.0 to 12.0 and calf bovine serum at pH 4.0 and 7.0 are reported. Additionally, the effect of pH, electrolyte and sample composition on the repassivation rate has been investigated. The potentials achieved during the abrasion of Ti6Al4V are the same as those characterizing pure titanium, which indicates that the corrosion current of both materials in the active state is due to the oxidation of titanium. However, commercial pure titanium displays a tendency to repassivate faster than Ti6Al4V in inorganic buffer solutions thanks to the lower critical current density and the higher catalytic activity towards the hydrogen evolution reaction observed on the pure metal in comparison with the alloy. Proteinaceous solutions like bovine serum, significantly slow down the anodic dissolution and the cathodic reactions both on titanium and the alloy. However, the repassivation rate of the Ti6Al4V is not affected by serum, while that of cp titanium significantly decreases both at pH 4.0 and 7.0.
Reading problems are common in children with ADHD and show strong covariation with these children’s underdeveloped working memory abilities. In contrast, working memory training does not appear to improve reading performance for children with ADHD or neurotypical children. The current study bridges the gap between these conflicting findings, and combines dual-task methodology with Bayesian modeling to examine the role of working memory for explaining ADHD-related reading problems. Children ages 8–13 (M = 10.50, SD = 1.59) with and without ADHD (N = 78; 29 girls; 63% Caucasian/Non-Hispanic) completed a counterbalanced series of reading tasks that systematically manipulated concurrent working memory demands. Adding working memory demands produced disproportionate decrements in reading comprehension for children with ADHD (d = −0.67) relative to Non-ADHD children (d = −0.18); comprehension was significantly reduced in both groups when working memory demands were increased. These effects were robust to controls for foundational reading skills (decoding, sight word vocabulary) and comorbid reading disability. Concurrent working memory demands did not slow reading speed for either group. The ADHD group showed lower comprehension (d = 1.02) and speed (d = 0.69) even before adding working memory demands beyond those inherently required for reading. Exploratory conditional effects analyses indicated that underdeveloped working memory overlapped with 41% (comprehension) and 85% (speed) of these between-group differences. Reading problems in ADHD appear attributable, at least in part, to their underdeveloped working memory abilities. Combined with prior cross-sectional and longitudinal findings, the current experimental evidence positions working memory as a potential causal mechanism that is necessary but not sufficient for effectively understanding written language.
The capacity to read develops throughout intensive academic learning and training. Several studies have investigated the impact of reading on the brain, and particularly how the anatomy of the brain changes with reading acquisition. In the present study, we investigated the converse issue, namely whether and how reading acquisition is constrained by the anatomy of the brain. Using multimodal MRI, we found that (a) the pattern (continuous or interrupted sulcus) of the posterior part of the left lateral occipito-temporal sulcus (OTS) hosting the visual word form area (VWFA) predicts reading skills in adults; that (b) this effect is modulated by the age of reading acquisition; and that (c) the length of the OTS sulcal interruption is associated with reading skills. Because the sulcal pattern is determined in utero, our findings suggest that individual difference in reading skills can be traced back to early stages of brain development in addition to the well-established socioeconomic and educational factors.
We introduce the Pemberton Happiness Index (PHI), a new integrative measure of well-being in seven languages, detailing the validation process and presenting psychometric data. The scale includes eleven items related to different domains of remembered well-being (general, hedonic, eudaimonic, and social well-being) and ten items related to experienced well-being (i.e., positive and negative emotional events that possibly happened the day before); the sum of these items produces a combined well-being index.
We used cyclic voltammetry (CV) and galvanostatic cycling test to optimize the synthesis condition and electrode composition for spinel LiMn2O4 cathode. Based on a synthetic approach of solid reaction, the most appropriate Li–Mn source for the synthesis of LiMn2O4 was found to be LiOH/MnO2 and the optimum synthesis condition was to react at 750°C in air for 18h. The LiMn2O4 such obtained has an initial specific capacity of 120–130mAh/g between 3.5 and 4.2V. In the electrode films, the carbon that was used as a conducting agent significantly affects performance of the LiMn2O4 electrode. Among the carbons examined in this work, we found that carbon black from Alfa Aesar was a better conducting agent and its appropriate content was around 10% in the LiMn2O4 electrode.
Iron is a key element in the development of Co-free AB5-type hydrogen storage alloys. The aim of this work is to systematically investigate the effects of Fe and Co on the electrochemical properties of LaNi4.6−x Mn0.4M x (M=Fe or Co, x =0, 0.25, 0.5 and 0.75) hydrogen storage alloys under relatively low temperatures (273, 253 and 233K). The results showed that substitution of Fe for Ni reduced the low temperature electrochemical performance much more seriously than that of Co. Exchange current density (I 0), charge-transfer resistance (R ct) and hydrogen diffusion coefficient (D) were determined based on the study of linear polarization, electrochemical impedance spectrum (EIS) and galvanostatic discharge, respectively. Both the hydrogen diffusion in the bulk of alloy particles and the electrochemical reaction at the alloy electrolyte interface were found to be greatly limited as the decrease of temperature. During the EIS analysis, interestingly, we found that the semicircle in the high frequency region increased dramatically with the decrease of temperature. The electrochemical process corresponding to this semicircle was proposed to be related to the oxide layer on the surface of alloy particles. Novel explanations of EIS response in metal hydride electrodes were proposed accordingly.