batterydata/paper-abstracts huggingface dataset:
Nano Ag4Bi2O5 as a novel cathode material of rechargeable alkaline batteries was successfully synthesized by precise control of precipitation reaction. KOH solution was used as precipitant and a mixture of AgNO3 and Bi(NO3)3 as Ag–Bi source. The experimental results indicate that concentration of KOH, reaction temperature and PH value have the effects on the structure and electrochemical property of the product. The material was characterized by means of XRD, FSEM and TG–DSC. The results show that the sample is single crystals with 50–100nm in width and 600–800nm in length. The electrochemical performances of Ag4Bi2O5 in the alkaline electrolyte were measured by galvanostatic method and cyclic voltammetry tests through film electrode. The sample shows three typical procedures during the charge–discharge, corresponding to Ag(II)–Ag(I), Ag(I)–Ag(0) and Bi(III)–Bi(0) transformation processes. This result is also verified by XRD tests. The Ag4Bi2O5 electrode has excellent electrochemical properties. It undergoes a current density as high as 20Ag−1, which greatly reduces charge time down to 55.9s. The electrode offers a cycling capacity of 330mAhg−1 and a cycling life more than 400 cycles at 1–2Ag−1.
A novel nanoporous polymer membrane comprised of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) co-polymer was prepared by phase inversion techniques using two different non-solvents. The films were subjected to scanning electron microscope (SEM) and nitrogen adsorption/desorption analysis. The morphology and porosity of the membranes are correlated with the chemical structure of the non-solvents used. Also, nanoparticle LiCr0.01Mn1.99O4 cathode material was prepared by solid-state reaction followed by ball milling. The prepared samples were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM). The charge–discharge behavior of lithium cells made from the coupling of the nanoporous polymer membrane with the LiCr0.01Mn1.99O4 nanoparticle cathode was studied. The cathode nanoparticles resulting from ball milling were found to be more important in enhanced cell performance than the nanostructure of the nanoporous polymer membranes.
Positive electrode material LiNi1/2Mn1/2O2 was synthesized via the carbonate co-precipitation method and the hydroxide precipitation route to study the effects of the precursor on its structural and electrochemical properties. The results of X-ray diffraction and Rietveld refinement show that the carbonate precursor of Ni2+ and Mn2+ exhibits one phase at a pH of 8.5, while the hydroxide deposit separates into Ni(OH)2 and Mn(OH)2 phases under the same experimental conditions. LiNi1/2Mn1/2O2 material prepared from the hydroxide precursor shows 8.9% Li/Ni exchange and a large capacity loss of 11.3% in the first 10 cycles. By contrast, more uniform distribution of transition metal ions and stable Mn2+ in the carbonate precursor contribute to only 7.8% Li/Ni disorder in the obtained LiNi1/2Mn1/2O2, which delivers a reversible capacity of about 182 mAh g−1 at a current rate of 14 mA g−1 between 2.5 and 4.8 V.
Amorphous LiCo1/3Mn1/3Ni1/3O2 thin films were deposited on the NASICON-type Li-ion conducting glass ceramics, Li1+x+y Al x Ti2−x Si y P3−y O12 (LATSP), by radio frequency (RF) magnetron sputtering below 130°C. The amorphous films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Li/PEO18–Li(CF3SO2)2N/LATSP/LiCo1/3Mn1/3Ni1/3O2/Au all-solid-state cells were fabricated to investigate the electrochemical performance of the amorphous films. It was found that the low-temperature deposited amorphous cathode film shows a high discharge voltage and a high discharge capacity of around 130mAhg−1.
The importance of reducing water crossover from anode to cathode in a direct methanol fuel cell (DMFC) has been well documented, especially if highly concentrated methanol fuel is to be used. A low-α membrane electrode assembly (MEA) with thin membrane is key to achieving this goal. The low water crossover from anode to cathode for these types of MEAs has traditionally been attributed to the use of a hydrophobic cathode micro-porous layer (MPL). However, it has recently been discovered that a hydrophobic anode MPL also reduces the water crossover, possibly even more significantly than a hydrophobic cathode MPL. In this work, we develop and use a 1D, two-phase transport model that accounts for capillary-induced liquid flow in porous media to explain how a hydrophobic anode MPL controls the water crossover from anode to cathode. We further show that a lower water crossover can lead to a lower methanol crossover via dilution of methanol in the anode catalyst layer. Finally, we perform a parametric study and show that a thicker anode MPL with greater hydrophobicity and lower permeability is more effective in reducing the water crossover.
A unified fundamental understanding of interfacial thermal transport is missing due to the complicated nature of interfaces. Because of the difficulty to grow high-quality interfaces and lack of materials characterization, the experimentally measured thermal boundary conductance (TBC) in the literature are usually not the same as the ideally modelled interfaces. This work provides a systematic study of TBC across the highest-quality (atomically sharp, harmonic-matched, and ultraclean) epitaxial (111) Al||(0001) sapphire interfaces to date. The comparison of measured high TBC with theoretical models shows that elastic phonon transport dominates the interfacial thermal transport and other mechanisms play negligible roles. This is confirmed by a nearly constant transmission coefficient by scaling the TBC with the Al heat capacity and sapphire heat capacity with phonon frequency lower than 10 THz. Finally, the findings in this work will impact applications such as electronics thermal management, thermoelectric energy conversion, and battery safety.
A three-dimensional porous Sb/Cu2Sb electrode is prepared by electrodeposition on a Cu foam substrate, and its electrochemical properties are investigated by a galvanostatic test for Na-ion batteries. The Sb/Cu2Sb electrode exhibits outstanding cycle stability and excellent rate capability; the charge capacity is sustained at 485.64 mA h g−1 over 120 cycles with a high coulombic efficiency of 97%, and the charge capacity retention is approximately 70% of the capacity at 0.1 C-rate, even at high 3 C-rate. The improvement in the electrochemical performance of the Sb/Cu2Sb electrode is attributed not only to the highly porous structure of the electrode but also to the improvement of bonding between substrate and active materials by the formation of Cu2Sb intermetallic. The sodiation/desodiation reactions of Sb/Cu2Sb with Na+ are proposed based on the ex-situ XRD analysis. After being fully desodiated, the electrode is restored to the crystalline Cu2Sb phase, confirming that the Cu2Sb phase reversibly reacts with Na+.
Vanadium pentoxide has been investigated for multivalent ion battery technologies but the structural characterization of inserted phases is poor, and conflicting reports exist in the literature. This study presents a critical overview of controversial aspects related to Mg and Ca insertion in α-V2O5 under diverse conditions by combined electrochemical and ex-situ XRD experiments. Galvanostatic tests are carried out in dry and wet alkyl carbonate-based electrolytes at RT and 100 °C. The formation of protonated phases with negligible divalent ion content if any is evidenced by Rietveld refinements of the XRD data, unambiguously dismissing the presence of AV2O5 (A: Mg, Ca) as electrochemical reduction products. Furthermore, thermal instability of V2O5 at 100 °C in alkyl carbonate solvents is demonstrated by XRD and TEM analysis and the formation of an orthorhombic phase with increased a parameter, most likely due to degradation favored by both water and temperature, is observed for both Mg and Ca. In order to assess the feasibility of the reverse reaction, fully intercalated AV2O5 (A = Ca, Mg) phases were also prepared by solid state reaction and oxidation attempted both electrochemically and chemically without evidence of any significant amount of Mg2+ or Ca2+ extraction, further corroborating the sluggish diffusion kinetics of divalent cations in α-V2O5.
Electrochemical impedance spectroscopy (EIS) and Mott–Schottky analysis were carried out to evaluate the electrochemical behavior of the passive films formed on the surface of coarse-grained (CG), fine-grained (FG) and ultra-fine-grained (UFG) 1050 Al alloy (AA1050) samples in alkaline media (pH value of 8.0) based on a modification of point defect model (PDM). The EIS results revealed that the polarization resistance increased from about 22.71–120.33 kΩ cm2 for UFG sample when compared to CG sample (annealed sample). The semiconductor properties of the passive films formed on CG, FG and UFG AA1050 samples in the test solution were investigated by employing Mott–Schottky analysis in conjunction with PDM. The results indicated that donor densities were in the range of 2.19 × 1021–0.61 × 1021 cm−3 and decreased with grain refinement. Finally, all electrochemical tests showed that the electrochemical behavior of AA1050 alloy was improved by decreasing the grain size, mainly due to the formation of thicker and less defective oxide films.
As part of the Department of Energy's Advanced Technology Development Program, lithium-ion cells of various sizes and chemistries are aged with periodic reference performance tests to ascertain degradation rates. The reference tests include a very slow discharge and charge based on a constant current equal to 1/25th of the rated capacity to elucidate the true electrochemical capacity of the cell. A differential analysis of these data helps to identify the individual kinetic and thermodynamic contributions of the anode and cathode. However, differential curves are very noisy, and previous smoothing methods included simple data reduction and moving averages. This paper introduces an alternative method of finding the differential voltage and differential capacity curves based on radial basis functions. The voltage profile is fit with a number of Gaussian curves, and the resulting model is differentiated. This approach also has the added advantage of assessing model uncertainty based on a bootstrap analysis. The radial basis function method was successfully applied to various lithium-ion chemistries tested under the Advanced Technology Development Program. The resulting differential capacity and differential voltage curves are generally smoother than the corresponding curves found by previous methods and also show little variance, indicating a good model fit. These results imply that the radial basis function technique is a more robust tool for assessing differential data.
In this paper we present MANTRA (Mobile ANticoagulant TheRApy), a project aimed at studying feasibility and acceptability of the introduction of mobile technology in the management of anticoagulant therapy involving both patients and health practitioners in their design. By the evaluation of the MANTRA Project, we developed a general approach to mHealth in the remote management of chronic diseases by supporting the communication among patients and healthcare practitioners. Patients usually have to make frequent visits to surgeries to meet nurses for the tests, and General Practitioners (GPs) for receiving drug prescriptions. We report on the implementation of the project as a proof of concept in London. A group of patients, General Practitioners, nurses, and healthcare assistants from the National Health Service (NHS) participated in design and evaluation phases. The distinct characteristics of the NHS as one of the world’s largest publicly funded health services posed a number of sociotechnical challenges to the design team. We present how we approached and addressed these challenges through MANTRA. Patients and Healthcare practitioners recognized the validity of our proposed design approach not only for supporting the remote therapy practice preserving an efficient and effective communication with the patients, but also as a way for better managing resources in anticoagulant clinics in the context of the NHS. With our research we explored the process that needs to be followed to develop a mobile system that would fit the sociotechnical ecosystem of anticoagulant therapy. Furthermore, we are now able to identify the changes that will be necessary in the ecosystem itself to make an effective use of the mobile system.
In the city of Aligarh (India), wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the agricultural crops. This practice has been polluting the soil, and the pollutants could possibly reach the food chain. For the above reason, soil irrigated with wastewater was sampled and monitored for the presence of genotoxic agents using three biological assays namely Ames Salmonella/mammalian microsome test, survival of SOS defective E. coli K-12 mutants and bacteriophage lambda systems. Extracts from soils were prepared using different organic solvents, i.e. methanol, acetonitrile and acetone. TA98 was found to be most sensitive strain to all the soil extracts. A significant decline in the survival of DNA repair defective E. coli K-12 mutants as compared to their isogenic wild-type counterparts were observed when treated with soil extracts. PolA was found to be the most sensitive strain. A remarkable decline in the plaque forming units was also observed when tested with the soil extracts. Extracts of soil that has been irrigated with ground water were also tested by the above three biological assays to compare the results.
Flexible energy storage devices are essential for emerging flexible electronics. The existing state-of-the-art Li-ion batteries are slowly reaching their limitation in terms of cost and energy density. Hence, flexible Na-ion batteries (SIBs) with abundance Na resources and Li–S batteries with high energy density become the alternative for the Li-ion batteries in future. This review summarizes the recent advances in the development of flexible electrode materials for SIBs with metallic matrix and carbonaceous matrix such as carbon nano-tubes, carbon nano-fiber, graphene, carbon cloth, carbon fiber cloth, and cotton textiles. Then, the potential prototype flexible full SIBs are discussed. Further, the recent progress in the development of flexible electrode materials for Li–S batteries based on carbon nano-fiber, carbon nano-tubes, graphene, and cotton textiles is reviewed. Moreover, the design strategies of suitable interlayer, separator, electrolyte, and electrodes to prevent the dissolution and shuttle effect of polysulfides in flexible Li–S batteries are provided. Finally some prospective investigation trends towards future research of flexible SIBs and Li–S batteries are also proposed and discussed. The scientific and engineering knowledge gained on flexible SIBs and Li–S batteries provides conceivable development for practical application in near future.
Reading problems are frequently reported by visually impaired persons. A closed-circuit television (CCTV) can be helpful to maintain reading ability, however, it is difficult to learn how to use this device. In the Netherlands, an evidence-based rehabilitation program in the use of CCTVs was lacking. Therefore, a standard training protocol needed to be developed and tested in a randomized controlled trial (RCT) to provide an evidence-based training program in the use of this device.
In this study, electric requirement of Gökceada, the biggest island of Turkey is analyzed that how can it be supplied with renewable energy sources. In order to consider the optimal system configuration of hybrid or non-hybrid renewable energy system, the HOMER program is used. At relevant studies which are done about renewable energy sources, it is seen that cost analysis are done according to annual average values. But in this study, HOMER program is used in order to make the system which is generated with computer, as real as possible. On the other studies, it is found out that various changes which are occurred in the year cannot be added to the system. With HOMER; the effect of values which vary by the time like electric load, wind speed and solar radiation, is considered and than the electric system are modelled. For each of these data, 8760 values are formed in HOMER. HOMER cannot model transient changes which is smaller than 1h. However; it is expressed that, hourly data are sufficient in order to analyze the system like this. In this study; systems which are composed of solar panels, wind turbines and batteries, auxiliary tools are modelled with considered various scenarios. Grid connection or diesel generators for backup power are also modelled. Values of components which form the renewable system of Gökceada, are determined by the simulations. The excess energy which occurs when the energy source is bigger than the load, can be sold to the grid and so, the cost of energy can be reduced. According to the simulation results; it is seen that, energy costs of wind energy systems are lower for Gökceada. It is revealed that wind energy is advantageous in Gökceada especially with grid sales according to the grid connected scenario.
Cross-stacked super-aligned carbon nanotube (SACNT) films are promising for use as current collectors in lithium-ion batteries because of their outstanding capability to decrease the weight and thickness of inactive material and strong adhesion to the electrodes. However, the relatively poor conductivity of SACNT films may limit their application to large-size electrodes or at high current rate. Herein, a facile approach is proposed to improve the conductivity of SACNT films by electron-beam deposition of a thin metal film on their surface. Such modification lowers the sheet resistance by three orders of magnitude while keeping the extremely small fraction of SACNT current collectors. The metal-coated SACNT films strongly inhibit polarization during the electrochemical reaction, resulting in improved cell performance compared with that of metal and uncoated CNT current collectors. The improvement in conductivity and cell performance achieved by this approach is so large that the effect of the increase of inactive material is overwhelmed, leading to increased gravimetric energy density.
Novel sandwich-like TiO2@C composite hollow spheres with {001} facets exposed are obtained through hydrothermal carbon-coating treatment for the first time. Based on investigations by transmission electron microscopy (TEM), scanning electron microscopy (FESEM), XRD, laser Raman spectra, and N2 adsorption–desorption isotherms, TiO2 shells are proved to be wrapped in porous carbon layers, which provide conductive support for TiO2, resulting the improvement in electronic conductivity and diffusion of Li+. Moreover, these TiO2 shells expose the reactive {001} facets, which facilitate Li+ insertion/extraction. Through combining the above advantages, TiO2@C composite hollow spheres show more superior rate capability and higher stability than TiO2 nanoparticles (Degussa P25), TiO2 nanosheets with {001} facets exposed, and TiO2 hollow spheres before carbon-coating. This method may be extended to synthesize other sandwich-like composite hollow spheres for energy storage.
Phaeodactylum tricornutum was exposed to various toxic substances (zinc, copper or dodecylbenzenesulfonic acid sodium salt) in accordance with the AlgalToxkit® protocol based on the UNI EN ISO 10253 method in order to quantitatively compare the responses obtained by traditional growth-rate inhibition tests with morphological (biovolume) and physiological (chlorophyll-a, phaeophytin ratio) endpoints. A novel approach is proposed for detecting early and sub-lethal effects based on biovolume quantification using confocal microscopy coupled with an image analysis system. The results showed that effects on both biovolume and the photosynthetic complex are sensitive and powerful early warning tools for evaluating sub-lethal effects of exposure. Specifically, biovolume showed significant sensitive and early responses for the tested surfactant. Qualitatively, we also observed structural anomalies and effects on natural auto-fluorescence in exposed cells that also represent potentially useful tools for ecotoxicological studies.
Increasing the level of wind power penetration beyond the present level in the Danish power system implies large challenges when it comes to energy management and system stability. Plug-in electric vehicles promise to contribute to the flexibility of the energy system by creating a link between the power system and the transportation sector and provide the possibility to make use of the inherent energy storage of a large electric vehicle (EV) fleet. The present work investigates the effects of different EV charging strategies on the balance between wind power production and consumption in a future Danish power system. The results show that an electrification of the transport sector will indeed reduce the excess of wind power, but additional mechanisms are needed if the full wind power potential in Denmark is utilized. Further it is foreseen that the vehicle-to-grid option (where the vehicle batteries are used as backup at times with little wind power production) will have very limited effects on the overall energy management and is more likely to be used only for regulation and reserve services, also in the longer perspective.
Acid absorption is a routine analytical method used in the manufacturing of lead oxide, that is, then further used to manufacture Pb-acid battery electrodes. This study had a new look at the definition of acid absorption being an indication of the acid reactivity of the oxide forming certain lead sulphate-related phases. Quantitative powder X-ray diffraction analysis of the acid reaction products showed there were significant differences in the phases formed that could be related to the amount of acid used in the acid absorption test. The study also showed that there were significant changes in the surface area of the oxides once they had reacted with the acid, where a traditionally slow reacting oxide such as β-PbO would show the greatest increase in material surface area once reacted with the acid. The accuracy of the method used by various laboratories was also studied by comparing the results obtained from two different methods and from three different laboratories. The results showed that there were significant differences between the reported values, and that one should with caution compare acid absorption numbers obtained from different laboratories.
Electrochemical impedance spectroscopy yields significant information concerning oxygen reduction because the time constants in the reduction process can be discriminated. In the present paper, the theoretical equations of the electrochemical impedance for the various oxygen reduction pathways are derived. In the cases of the two-electron and direct four-electron reductions, the electrochemical impedance simply shows one capacitive semicircle on the complex plane. When the oxygen is reduced by an indirect four-electron reaction or a two-electron reduction followed by a disproportionation reaction, the complex plane plot of the electrochemical impedance shows two semicircles. In this case, the semicircle in the low frequency range is related to the time constant of adsorption and desorption of the reaction intermediate involved in the consecutive reactions. The conditions that the electrochemical impedance shows an inductive semicircle in the low frequency range are discussed on the basis of numerical simulations. The channel flow double electrode was used to measure the j–E curve and electrochemical impedance of glassy carbon, Pt and Ag electrodes at oxygen reduction potentials in alkaline solution. The complex plane plots of the electrochemical impedance of Ag and Pt electrodes show an apparent inductive semicircle, indicating the presence of the reaction intermediate HO2 −.