batterydata/paper-abstracts huggingface dataset:
Body composition testing has been advocated as part of fitness test batteries in an educational effort to promote health-related fitness, and to prevent public health problems like obesity. However, the measurement of the body composition of children and youth, especially involving the use of skinfold calipers, has raised concerns. In two experiments the cognitive and affective consequences of skinfold caliper use in a 7th grade (155 boys, 177 girls, total N = 332) health/physical education context were examined. Experiment 1 demonstrated that the students could be taught to accurately measure a partner and/or significantly learn body fatness-related concepts compared to controls. It was also shown that inexpensive plastic Fat Control calipers produced accurate measurement. Experiment 2 was designed to replicate the significant cognitive outcome effects, and also to test the hypothesis that psychological damage is a likely consequence of skinfold caliper use-and that hypothesis was refuted. Specifically, knowledge scores, and outcome scores on adapted affect scales (e.g., PANAS, MAACL), physical self-esteem scales (CY-PSPP) and on the Social Physique Anxiety Scale supported the premise that skinfold calipers can be used in an educational context to facilitate cognitive learning without causing adverse affective consequences.
Formaldehyde, resorcinol, and sodium acetate were used to synthesize the carbon aerogels by ambient pressure drying. The effect of the ratio of resorcinol and sodium acetate for carbon aerogels was researched by scanning electron microscope and Brunauer-Emmett-Teller characterizations. Then the carbon aerogels were applied in synthesizing sulfur/carbon aerogel composites through a melting method, the specific capacity and cycle performance of lithium/sulfur batteries that adopted the prepared composites as cathodes were measured by galvanostatic discharge–charge. X-ray diffraction, conductivity measurement, cyclic voltammetry, and electrochemical impedance spectra tests were also carried out to help explain the electrochemical performance. Finally, the carbon aerogel with the best properties was chosen for the comparative study of replacement of water by acetone as solvent in the preparation of carbon aerogels. According to our study, the carbon aerogel prepared by ambient pressure drying with high electrical conductivity, controllable pore structure, and high specific surface area was proposed to be used for lithium/sulfur batteries, and the key factors to the performance of carbon aerogel/sulfur composites were discussed.
This study concerns the efficient electrochemical reduction of molecular oxygen (O2), in O2-saturated 0.1M KOH solution, to OH− through a four-electron reduction pathway by a novel binary catalyst that is comprised of two kinds of catalysts, i.e., Au nanoparticles (nano-Au) and manganese oxide nanoparticles (nano-MnOx) electrodeposited onto a relatively inert substrate, e.g., glassy carbon (GC) electrode. The nano-Au catalyst is efficiently used for the electro-reduction of O2 to hydrogen peroxide through a two-electron reduction pathway at a reasonably low overpotential. While the latter (i.e., nano-MnOx) is effectively used for the subsequent catalytic decomposition of the electrogenerated hydrogen peroxide to water and molecular oxygen. The dependence of the electrocatalytic activity of the proposed binary catalysts towards the oxygen reduction on the loading level of both species has been investigated in this paper. This is done aiming at the preparation of a binary catalyst composed of the optimum amounts of both species which supports an apparent four-electron reduction of O2 at sufficiently low overpotential in replacement of the costly Pt-based electrocatalysts.
Hierarchical nanostructures of hydrated α-manganese dioxide (MnO2) are prepared and their kinetics properties are characterized using scanning electrochemical microscopy (SECM). The SECM measurements are focused on the feedback mode approach curve to extract the effective heterogeneous charge transfer rate constant and illustration of the ultramicroelectrode (UME) tip-substrate cyclic voltammetry. Positive feedback current is observed during the SECM approach curve, indicating the efficient charge transfer process into the MnO2 electrode. These studies complement electrochemical impedance spectroscopy and charge discharge measurements that are carried out to determine the effectiveness of the resultant MnO2 for supercapacitor application. Specific capacitance as high as 356Fg−1 at 2Ag−1 is achieved and there is no degradation of the capacitance after 2000 cycles of cycling test, indicating its good capacitive properties for supercapacitor application.
Fe-triethanolamine is a promising candidate as anolyte for redox flow batteries (RFBs), owning to its low potential, high solubility and low cost. We report here a new dinuclear structure of this complex at solid state when prepared with a stoichiometric amount of triethanolamine and iron in basic medium, whereas more than two equivalents of ligands are usually used to prepare Fe-triethanolamine for RFBs application. We achieve a calibration curve to estimate Fe(III) concentration in solution and coulometric experiments highlight a one-electron reduction process per iron atom, corresponding to the reduction of the two Fe(III) atoms of the dinuclear complex into Fe(II). A solubility higher than 1.2 mol dm−3 can be reached for Fe-triethanolamine with the new synthesis proposed in this work. All-Fe alkaline RFBs implemented with Fe-triethanolamine exhibit good performances in terms of coulombic, voltage and energy efficiencies, and is stable over a hundred of cycles. A power density around 80–120 mW cm−2 is reached and the high solubility of Fe-triethanolamine allows the achievement of high volumetric capacities, superior to 10 Ah dm−3.
In order to optimize the operating parameters of battery management systems for electric and hybrid vehicles, great interest has been shown in achieving the maximum permissible charging currents during recuperation, without causing a cell damage due to lithium plating, in relation to the temperature, charge quantity and state of charge. One method for determining these recuperation currents is measuring the cell thickness, where excessively high charging currents can be detected by an irreversible increase in thickness. It is not possible to measure particularly small charge quantities by employing mechanic dial indicators, which have a limited resolution of 1 μm. This is why we developed a measuring setup that has a resolution limit of less than 10 nm using a high-resolution contactless inductance sensor. Our results show that the permissible charging current I can be approximated in relation to the charge quantity x by a correlating function I = a / ( x ) which is compliant with the Arrhenius law. Small charge quantities therefore have an optimization potential for energy recovery during recuperation.
The universal period-tripling system has been discovered in various astronomical, geophysical, and biological phenomena in the range of periods from 1.64 billion years to 50 years; we then confirmed its existence on a scale of up to 10–15 seconds based on examples of human memory and hearing, several technical and medical devices, and, finally, in the settings of human and animal vision. This unprecedented multiscale discrete spectrum of periods has been studied thus far exclusively on the basis of literature data; as a result, it has been shown that many systems of a diverse nature, including the most common ones, operate against the background of a dimensionless spectrum of ~3k/2m periods. This is close to the spectrum of a stochastic attractor, which gives a Pythagorean musical octave. We confirm the result of this phenomenological generalization experimentally by testing various generators of electrical oscillations.
Lithium zinc titanate (Li2ZnTi3O8) is a desirable anode material for lithium-ion batteries (LIBs) due to its low cost, non-toxicity and high safety. However, the low electronic conductivity and inferior rate capability hinder the commercial application of Li2ZnTi3O8. Carbon coating can not only effectively enhance the electronic conductivity of Li2ZnTi3O8 but also suppress the growth of particle size in the sintering process. In addition, carbon can provide extra capacity when using Li2ZnTi3O8/C as an anode. Here, a simple yet powerful strategy is introduced to in situ prepare nitrogen-doped carbon coating on Li2ZnTi3O8 nanoparticles using ZIF-8 as carbon, nitrogen and zinc sources. After sintering at 700°C the obtained nanocomposite shows large discharge specific capacity of 287.3mAhg−1 at 0.5Ag−1, excellent cycling stability (>90% capacity retention after 200cycles corresponding to the largest value at 2Ag−1) and outstanding rate capability at 4 and 5Ag−1. These properties, combined with its high safety and ease of fabrication, make such Li2ZnTi3O8@C–N nanocomposite an ideal anode candidate for LIBs.
Fuel cells were an important technology that could be used for a variety of power applications. The direct methanol fuel cell (DMFC) was a promising candidate for powering portable electronic devices such as laptops, digital cameras and cell phones. Compared with conventional batteries, DMFCs could provide a higher power density with a longer lifetime and almost instant recharging. However, many issues related to the design, fabrication and operation of miniaturised DMFC power systems remain unsolved. Fuel delivery was a key issue in determining the performance of a DMFC. To achieve the desired performance, an efficient fuel delivery system was required to provide an adequate amount of fuel for consumption and to remove the carbon dioxide generated in the fuel-cell devices. This paper presented a detailed description of various fuel flow-field designs for DMFCs and their respective advantages. This paper also discussed the current approaches and challenges in existing fuel delivery and fuel storage systems, including active and passive DMFCs and micro-fluidic systems. The commercialisation of DMFCs with storage was presented.
Using amorphous FePO4 (a-FePO4) nanoparticles with a high purity, a narrow size distribution and good dispersion, we successfully developed a new strategy to generate a uniformly dispersed a-FePO4-CNT nano-composite using the interface interaction between surface-modified a-FePO4 and CNT dispersion under mild sonication. The uniformly dispersed a-FePO4-CNT nano-composite exhibited the best performance and long-term stability as a cathode material in a lithium-ion battery compared to previously reported results. The developed nano-composite could deliver a theoretical specific capacity at 0.1 C, 162 mAh g−1 at 1 C and 117 mAh g−1 at 5 C. No capacity fading was observed at 1 C after 500 cycles, and nearly 90% of the initial discharge capacity could be retained at 5 C after 2000 cycles. This study confirms the validity of the proposed strategy to construct a cathode structure, and also describes the potential of a-FePO4 for building high-power energy-storage and conversion systems.
A novel layered material of LiNi0.32Mn0.33Co0.33Al0.01O2 with α-NaFeO2 structure is synthesized by sol–gel method. X-ray diffraction (XRD) shows that the cation mixing in the Li layers of it is decreased. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are employed to characterize the reaction of lithium-ion insertion and extraction from materials. The results indicate that the structure of LiNi0.32Mn0.33Co0.33Al0.01O2 is more stable than that of the LiNi0.33Mn0.33Co0.33O2. The capacity retention of LiNi0.33Mn0.33Co0.33O2 after 40 cycles at 2.0C is only 89.9%, however, that of the LiNi0.32Mn0.33Co0.33Al0.01O2 is improved to 97.1%. The capacity of the LiNi0.32Mn0.33Co0.33Al0.01O2 at 4.0C remains 71.8% of the capacity at 0.2C, while that of the LiNi0.33Mn0.33Co0.33O2 is only 54.3%. EIS measurement reveals that the increase in the charge transfer resistance during cycling is suppressed in the LiNi0.32Mn0.33Co0.33Al0.01O2 material.
Co2.85Si0.15O4 solid solution was successfully synthesized using a facile hydrothermal method for the first time. The structural and morphological features of prepared powders were thoroughly investigated by different techniques. The Rietveld refinement assured the formation of spinel structured Co2.85Si0.15O4 without any impurity phases. The FT-IR and Raman spectrums revealed the presence of SiO2, and carbon with the Co2.85Si0.15O4 solid solution. The X-ray photoelectron spectroscopy inferred that the Co exists in +2 and +3 oxidation state and Si exists in multivalence state. Surface morphological analysis demonstrated that the formation of cube shape Co2.85Si0.15O4 microparticles are embedded in to amorphous SiO2 matrix, which was confirmed using SAED pattern. The inactive nature of amorphous SiO2 in Co2.85Si0.15O4 was confirmed by CV studies. Consequently, it was electrochemically active while making composite with carbon, since it reduces SiO2 into SiOx. The cycling stability of Co2.85Si0.15O4@C composite provided superior electrochemical performance than the pristine Co2.85Si0.15O4. The composite delivers the specific capacity of 444mAhg−1 at 75mAg−1 after 50 cycles with feeble capacity fading. The EIS spectra corroborates the composite exhibit the lower charge transfer resistance (Rct) and solid electrolyte interphase resistance (RSEI) compared to pristine Co2.85Si0.15O4. This further confirmed that carbon composite enhanced the inherent conductive nature and rate capability of pristine Co2.85Si0.15O4 electrode.
Investigations describing incidents with electrochemical cells, in which the cell heats up and is either destroyed or severely damaged, causing damage to the immediate environment of the cell, are frequently referred to as “thermal runaway“. However, the term is used in most papers without a clear definition of what is meant. This article analyses in more detail what exactly could be meant by this term, and intends to offer a precision of the usage of the term “thermal runaway” which will help to find solutions for thermal runaways and their propagation and safe handling in an electrochemical system like a lithium-ion battery. In addition, the key role of a fail-safe battery management system in preventing a thermal runaway is discussed.
We present a model of the lithium–sulfur (Li/S) battery based on a multi-step, elementary sulfur reduction mechanism including dissolved polysulfide anions. The model includes a description of the evolution of solid phases in the carbon/sulfur composite cathode as well as multi-component (Li+, PF 6 – , S8, S 8 2 – , S 6 2 – , S 4 2 – , S 2 2 – , S2–) mass and charge transport in the liquid electrolyte. The chemical reaction mechanism consists of a Li/Li+ oxidation reaction at the anode and a six-step polysulfide reduction mechanism at the cathode. The modeling framework allows for the simulation of charge and discharge profiles as well as electrochemical impedance spectra. The latter are obtained via a voltage step/current relaxation technique based on the physicochemical model without the need for applying equivalent circuit models. The results indicate that the discharge behavior of this Li/S cell is governed by the presence of solid reactant and product phases in exchange with the dissolved polysulfide anions. The first and last stages of the discharge are characterized by the presence of solid S8 and Li2S, respectively, while the intermediate stage corresponds to a situation where all chemical compounds are dissolved in the electrolyte.
A nanocomposite of graphene oxide (GO), yttrium oxide (Y2O3) nanoparticles, and Nafion was prepared and used to modify a glassy carbon electrode (GCE) by a simple drop casting technique. The modified electrode sensor was then used for the electrochemical detection of l -3,4-dihydroxyphenylalanine (l -DOPA). Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of the modified electrode. Square wave voltammetry (SWV) and cyclic voltammetry (CV) were also employed for electrochemical detection of l -DOPA and characterization of the modified electrode. The effect of SWV parameters, ratio of GO:Y2O3 in the composite, and the electrolyte solution pH on the oxidation peak currents were examined to optimize experimental conditions. The results of the optimization steps revealed the best experimental parameters based on the current response for oxidation of l -DOPA were 55 mV for pulse amplitude, 10 mV for step potential, 30 Hz for frequency, 2:1 for the GO:Y2O3 ratio, and 3.5 for pH. Under these conditions, the GCE modified with GO-Y2O3 showed a linear current response for oxidation of l -DOPA in the range of 0.5–350 μM with a limit of detection (LOD) of 0.05 μM, a limit of quantification (LOQ) of 0.17 μM, and a heterogeneous rate constant (k°) of 1.07 × 10−2 cm s−1. Increased sensitivity compared to a GO modified electrode was clearly observed. The electrode also exhibited selectivity towards l -DOPA in the presence of common interferences such as ascorbic and uric acid, and excellent stability and reproducibility over time. Finally, the modified electrode was utilized for the detection of l -DOPA in biological samples.
For application to electric vehicles, the fast charging of lithium-ion batteries is required. However, lithium-ion batteries are faced with undesirable Li plating causing the capacity fading with low Coulombic efficiency at high charge rates. Here, we present the effects of solid electrolyte interphase structures of the graphite anode and linear carbonate solvents on fast charging capability of LiNi0.6Co0.2Mn0.2O2/graphite full cells. To control the nature of the interfacial layer on the graphite anode affecting the Li plating behavior, we exploit three kinds of additives, ethylene carbonate, fluoroethylene carbonate and vinylene carbonate, as anode solid electrolyte interphase formers. In addition, the effect of ethyl methyl carbonate and dimethyl carbonate on the solvation and transport of high concentrations of Li ions de-intercalated from the LiNi0.6Co0.2Mn0.2O2 cathode in a full cell at high charge rates is explored in fluoroethylene carbonate-based electrolytes. Our investigation reveals that the combination of fluoroethylene carbonate and dimethyl carbonate in the electrolyte enables fast-charging LiNi0.6Co0.2Mn0.2O2/graphite full cells showing the excellent capacity retention of 79% after 1000 cycles at a high charging current density of 6 mA cm−2, corresponding to 2C, and a discharge rate of 1C without Li plating on the graphite anode.
The rechargeable aprotic Li–O2 batteries, of much interest because of their high energy capacity, suffer from many challenges, one of which is the large overpotential resulting in low efficiency and some detrimental side reactions. Although porous cathodes with electrocatalytic activity that have reduced overpotential have been designed by improving the Li2O2 decomposition kinetics or regulating the discharge products, achieving an ideal charge potential of <3.5 V still faces significant challenges because the origin of high charge potential is poorly understood. Here, we revealed that the interfacial charge transfer at a hetero-structural Li2O2@cathode makes a major contribution to the overpotential through comprehensively studying Li+/O2 desorption and charge transfer kinetics in theory and experiments. A strategy of band alignment was proposed to reduce interfacial charge transfer and thus the overpotential. High-throughput calculations were performed to screen effective cathodes, of which the calculated charge potentials are in good agreement with the available experimental data. According to the screened cathode materials, 3d-metal carbides/nitrides with a low-valence-state metal and noble-metal oxides with a high-valence-state metal exhibit high electrochemical activities for reducing charge potential in Li–O2 batteries. Unreported cathodes such as MnN and Cr2O3 are predicted as high-activity cathodes with low charge potentials of <3.5 V.
A clay-drug nanohybrid was prepared by interfacial boundary ion exchange reaction, from which the release mechanism of a poorly water soluble drug, itraconazole, was studied systematically. The effect of cation types on drug release was investigated on the basis of a UPS 25 guide line and the effect of Laponite dissolution was also studied at pH=1.2. To describe the release patterns, mathematical modeling was preformed using first-order, Elovich, parabolic diffusion, and power function equations.
The preparation, structural characterization and study of the electrochemical behavior in lithium cells of Co1−2y Fe y Ni y Sb3 (0.125<y≤0.5) compounds is described. The refinement of X-ray diffraction (XRD) patterns evidenced the skutterudite-type structure for all compositions, with an increasing partial filling of 2a sites. The first discharge of lithium anode cells shows two plateaus. The plateau at higher potential, which occurs at ca. 0.8V and extends from ca. 150 to 250Ah/kg depending on “y”, is mainly assigned to side reactions of lithium with the electrolyte, as confirmed by 7Li NMR. The second plateau occurs at 0.5–0.6V and is assigned to Li–Sb alloys formation. The charge of the cell shows that only the second step is reversible. Further discharge/charge cycles present a plateau at 0.8V in the discharge and at 1.05V in the charge, which agree well with the Li–Sb alloying/de-alloying process. Extended cycling results on a loss of capacity, to stabilize over 100Ah/kg after 20 cycles.
Hybrid capacitor configurations are now of increasing interest to overcome the current energy limitations of supercapacitors. In this work, we report a lithium ion capacitor (LIC) entirely based on graphene. On the one hand, the negative –battery-type- electrode consists of a self-standing, binder-free 3D macroporous foam formed by reduced graphene oxide and decorated with tin oxide nanoparticles (SnO2-rGO). On the other hand, the positive –capacitor-type- electrode is based on a thermally expanded and physically activated reduced graphene oxide (a-TEGO). For comparison purposes, a symmetric electrical double layer capacitor (EDLC) using the same activated graphene in 1.5 M Et4NBF4/ACN electrolyte is also assembled. Built in 1 M LiPF6 EC:DMC, the graphene-based LIC shows an outstanding, 10-fold increase in energy density with respect to its EDLC counterpart at low discharge rates (up to 200 Wh kg−1). Furthermore, it is still capable to deliver double the energy in the high power region, within a discharge time of few seconds.
Hollow NiSe−CoSe samples have been synthesized for the first time via a one-pot solvothermal approach. The strategy is robust enough to synthesize NiSe–CoSe nanoparticles with different NiSe to CoSe ratios but with a similar hollow structure. Co ions in the NiSe–CoSe nanoparticles play decisive role for formation of the hollow structure; otherwise, the nanoparticles become solid for the NiSe sample. When used as the positive electroactive materials for energy storage, the NiSe–CoSe samples show excellent electrochemical activity in alkaline electrolyte. Using the synergistic effect between NiSe and CoSe, the electrochemical performance of NiSe–CoSe can be tuned by varying the NiSe to CoSe ratios. The NiSe–CoSe sample with a NiSe to CoSe ratio of 4:2 shows the best electrochemical performance in terms of superior specific capacity, improved rate capability and excellent cycling stability. In addition, the electrochemical performance of NiSe–CoSe sample with a NiSe to CoSe ratio of 4:2 is also evaluated via assembling hybrid supercapacitors with RGO, and the hybrid supercapacitor delivers both high power and energy densities (41.8 Wh kg−1 at 750 W kg−1 and 20.3 Wh kg−1 at 30 kW kg−1).