batterydata/paper-abstracts huggingface dataset:
A nonflammable polymeric gel electrolyte film has been developed for rechargeable lithium battery systems. The gel film consists of poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) swollen with LiPF6 solution of a ternary solvent containing nonflammable trimethyl phosphate (TMP). The addition of TMP to mixed ethylene carbonate plus diethyl carbonate (EC+DEC) solvent prevented the LiPF6 salt from the thermal decomposition. The LiPF6 solutions containing 20vol% or higher content of TMP were fire-retardant. High ionic conductivity was obtained for both the liquid and the gel electrolyte systems containing 55vol% of TMP in the liquid components: 7.1×10−3 Scm−1 for the liquid and 2.9×10−3 Scm−1 for the gel electrolytes at 20°C. A wide potential window (−0.5 to 4.5V versus Li/Li+) and the redox activity of the electrode materials were established for the gel electrolyte containing TMP.
The urban heat island (UHI) is a well-documented effect of urbanization on local climate, identified by higher temperatures compared to surrounding areas, especially at night and during the warm season. The details of a UHI are city-specific, and microclimates may even exist within a given city. Thus, investigating the spatiotemporal variability of a city’s UHI is an ongoing and critical research need. We deploy ten weather stations across Knoxville, Tennessee, to analyze the city’s UHI and its differential impacts across urban neighborhoods: two each in four neighborhoods, one in more dense tree cover and one in less dense tree cover, and one each in downtown Knoxville and Ijams Nature Center that serve as control locations. Three months of temperature data (beginning 2 July 2014) are analyzed using paired-sample t tests and a three-way analysis of variance. Major findings include the following: (1) Within a given neighborhood, tree cover helps negate daytime heat (resulting in up to 1.19 ∘C lower maximum temperature), but does not have as large of an influence on minimum temperature; (2) largest temperature differences between neighborhoods occur during the day (0.38–1.16 ∘C difference), but larger differences between neighborhoods and the downtown control occur at night (1.04–1.88 ∘C difference); (3) presiding weather (i.e., air mass type) has a significant, consistent impact on the temperature in a given city, and lacks the differential impacts found at a larger-scale in previous studies; (4) distance from city center does not impact temperature as much as land use factors. This is a preliminary step towards informing local planning with a scientific understanding of how mitigation strategies may help minimize the UHI and reduce the effects of extreme weather on public health and well-being.
The present paper introduces the results of a spatial-economic analysis that identifies the least cost rural electrification options that can bring the persistent energy poverty to an end in Sub Saharan Africa. The rationale behind the analysis is that the applicable energy technologies have gone through fundamental changes and these have profound effects on the competitiveness of the various options. The least cost distributed generation options are calculated for each geographical location for mini hydro, off grid PV and diesel generators options and it is compared to the electricity grid extension. The methodology presented in this manuscript organises the scarcely available energy-related local and regional geo-information into comprehensible maps. The set of tools presented and the results based on those analyses can support decision and policy makers to plan for the least-cost rural electrification options while also adapting to the most effective way to reduce energy poverty. This can help in the national rural electrification plans by delineating which communities cannot be reached by existing grid without excessive extension costs and gives the alternative distributed generation option.
ZnO displays similar redox and alloying chemistry to the tin oxides on Li insertion. It might, therefore, be expected to be an interesting network modifier for tin oxides. ZnO/SnO2 composites show degradation in cycling performance, however, for low ZnO levels, cyclability is improved by some milling, however, for high ZnO levels milling degrades performance, probably due to the increase of ZnO activity. On testing ZnO, it is found that it cycles very poorly. Both electrochemical and X-ray studies indicate that highly crystalline Li x Zn alloys are formed. It seems that the high degree of crystallisation on insertion is the determinant factor leading to the poor performance of ZnO and ZnO/SnO2 composites compared to SnO2.
To find a novel high-performance anode material for lithium-ion batteries, a new form of carbon characterized by highly crimped and crystalline nanofibrillar microtextures was produced by heat treating polyacrylonitrile/FeCl3 hybrid precursor and subsequent thermal annealing under hydrogen gas. This form of carbon exhibits a rechargeable capacity of ∼630mAh/g, which is superior to that of graphite, with a Coulomb efficiency of ∼70%. Further, the new form of carbon was found to exhibit an efficiency of lithium ion insertion/extraction of ∼100% in the voltage range from 0.06 to 0.80V, with a capacity of ∼400mAh/g. We speculate that this excellent capacity is due to the characteristic structure of this form of carbon, i.e. its highly entangled web-like hyperstructure consisting of highly crimped and crystalline nanofibrillar microtextures, which enables good permeation and has high resilience to volume deformation during the insertion/extraction of Li ions.
The energy supply is a key issue for underwater equipment used in seabed exploration, especially in deep water. The high-pressure seawater in deep water contains massive hydrostatic energy and it is a potential clean energy source. The type of energy has advantages of low cost and relatively high reliability in deep water. A novel drive system which converts seawater's hydrostatic energy to mechanical energy is proposed for seabed cone penetration test rig. The hydrostatic drive system uses variable displacement hydraulic motor and PID control method to ensure stabilization of penetration speed and high energy efficiency. The mathematical model of the drive system is built and the comprehensive analysis is conducted. The analysis results based on the real resistance data indicate that the drive system can keep the penetration speed stable when encountering severely fluctuating sediment resistance at different depth of water and achieve high energy efficiency. The mathematical model is validated by the comparison of the results of mathematical model with simulation model based on the commercial software. Because of the high efficiency, the drive system can output considerable amount of energy which is comparable to underwater large battery pack carried by present deep-water cone penetration test rig.
Industrial scale manufacturing with tunable properties of graphene nano-sheets has been a practical concern in many applications. This study focuses on, a physical electro-chemistry approach for the synthesis of few-layer graphene nano-sheets (FLGNSs) in a scalable manner. The intercalates are bias-driven anions towards the working electrode of bulk pyrolytic graphite sheet followed by their exfoliations as FLGNSs. In-situ electrochemical studies confirm a higher rate of exfoliation with an increase in the concentration of intercalates. Based on colloidal conductivity and particle size analyses, the degree of crystallinity and effect of variation in intercalates is explored. Rate of oxidation, defects, morphological variation, and number of layers with variation of intercalate concentration have been studied by XRD, Raman spectroscopy, FTIR, UV–Vis spectroscopy, XPS, and electron microscope based analyses. Cost-effectiveness of the electrochemical process in producing FLGNSs is assessed by considering cost of raw materials used in this laboratory process.
A three-dimensional ordered macroporous (3DOM) cobalt ferrite (CoFe2O4) was prepared using polystyrene (PS) colloidal crystal template. The scanning electron microscopy (SEM) and the transmission electron microscopy (TEM) micrographs showed that the as-prepared CoFe2O4 material had a typical 3DOM structure, which was constructed with about 130nm-sized macropores and 10–20nm-sized walls. The obtained CoFe2O4 material had a specific surface area of 66.67m2 g−1, and could deliver a relatively high capacity of 702mAhg−1 (about double that of graphite) at a current density of 0.2mAcm−2 after 30 cycles. Owing to the 3DOM nanoarchitecture, the as-prepared CoFe2O4 electrode exhibited a good rate performance. The results suggest a promising application of the 3DOM CoFe2O4 as anode material for lithium ion batteries.
In order to develop a LISICON separator for an aqueous lithium–air battery, a thin membrane was prepared by a tape-casting of a Li1.3Al0.3Ti1.7 (PO4)3–AlPO4 based slip followed by a sintering step. By optimizing the grain sizes, the slip composition and the sintering treatment, the mechanical properties were improved and the membrane was reduced to a thickness of down to 40 μm. As a result, the ionic resistance is relatively low, around 38 Ω for a 55 μm membrane of 1 cm2. One side of the membrane was coated with a lithium oxynitrured phosphorous (LiPON) thin film to prevent lithium metal attack. Lithium metal was electrochemically deposited on the LiPON surface from a saturated aqueous solution of LiOH. However, the ionic resistance of the LiPON film, around 67 Ω for a 1.2 μm film of 1 cm2, still causes an important ohmic loss contribution which limits the power performance of a lithium–air battery.
Expression in Escherichia coli represents the simplest and most cost effective means for the production of recombinant proteins. This is a routine task in structural biology and biochemistry where milligrams of the target protein are required in high purity and monodispersity. To achieve these criteria, the user often needs to screen several constructs in different expression and purification conditions in parallel. We describe a pipeline, implemented in the Center for Optimized Structural Studies, that enables the systematic screening of expression and purification conditions for recombinant proteins and relies on a series of logical decisions. We first use bioinformatics tools to design a series of protein fragments, which we clone in parallel, and subsequently screen in small scale for optimal expression and purification conditions. Based on a scoring system that assesses soluble expression, we then select the top ranking targets for large-scale purification. In the establishment of our pipeline, emphasis was put on streamlining the processes such that it can be easily but not necessarily automatized. In a typical run of about 2 weeks, we are able to prepare and perform small-scale expression screens for 20–100 different constructs followed by large-scale purification of at least 4–6 proteins. The major advantage of our approach is its flexibility, which allows for easy adoption, either partially or entirely, by any average hypothesis driven laboratory in a manual or robot-assisted manner.
Distributed generation (DG) is emerging as an alternative to a centralized electricity-generation system. The goals of DG include the minimization of the environmental impacts of energy production and introduction of new renewable energy-sources to the distribution network. Superconducting devices are also proposed for DG because of their high efficiencies as well as smaller size and more stable operation during peak loads. This study concentrates on the environmental benefits of superconducting machinery by comparing suitable devices with their competitors in DG-networks. Exploitable superconducting devices in DG include superconducting magnetic energy-storage (SMES), flywheels and cable systems. Life-cycle assessment (LCA) is used as a tool in comparisons of energy-storage devices suitable for DG: SMESs, flywheels and batteries. In LCA, all material inputs, energy consumptions, wastes, and emissions are assessed over the life-cycle of the product. Finally, a commercialization schedule for HTS-cables is presented and an unconventional concept for a DG-network is suggested for further examination.
Bisphenol-A (BPA) is an endocrine-disrupting chemical that may affect the hormones and their receptors. The aim of this study is to determine whether BPA has an effect on the development of nonfunctional adrenal incidentaloma (NFAI).
Solid polymer electrolytes (SPEs) synthesized by the sol–gel process and designated as di-ureasils have been prepared through the incorporation of lithium perchlorate, LiClO4, into the d-U(2000) organic–inorganic hybrid network. Electrolytes with lithium salt compositions of n (where n indicates the number of oxyethylene units per Li+ ion) between ∞ and 0.5 were characterized by conductivity measurements, cyclic voltammetry at a gold microelectrode, thermal analysis and Fourier transform Raman (FT-Raman) spectroscopy. The conductivity results obtained suggest that this system offers a quite significant improvement over previously characterized analogues doped with lithium triflate [S.C. Nunes, V. de Zea Bermudez, D. Ostrovskii, M.M. Silva, S. Barros, M.J. Smith, R.A. Sá Ferreira, L.D. Carlos, J. Rocha, E. Morales, J. Electrochem. Soc. 152 (2) (2005), A429]. “Free” perchlorate ions, detected in all the samples examined, are identified as the main charge carriers in the sample that yields the highest room temperature conductivity (n =20). In the di-ureasils with n ≤10 ionic association is favoured and the ionic conductivity drops.
The ability of drugs that reduce NMDA receptor activity on the volitional consumption of ethanol in the genetic drinking rat, mHEP line, was investigated. After the consumption of ethanol solutions and water by each male or female mHEP rat had stabilized on its preferred concentration, different doses of LY 274614, a competitive NMDA antagonist, MK 801, a non-competitive NMDA antagonist, (+)-HA-966 or ACPC (1-aminocyclopropane-1-carboxylic acid), antagonists of the glycine site were administered daily for three days. The dose of 3.0mg/kg i.p. LY 274614 reduced the consumption of ethanol by 64% compared to the pre-treatment baseline, while 0.3mg/kg of MK 801 reduced consumption by 44%, 20mg/kg (+)-HA-966 reduced consumption by 47% and 300mg/kg of ACPC reduced consumption by 30%. These doses of LY 274614 and MK 801 reduced the ability of Sprague-Dawley rats to walk on a rotorod. Effects of these drugs on food intake were small except for the 20mg/kg dose of (+)-HA-966. Therefore, the drugs did not have an anti-caloric effect and manipulations of the glutamatergic system through NMDA receptors may modify the consumption of ethanol. This interaction should be explored further for its therapeutic potential and to better understand the control by central neuronal systems of the consumption of ethanol.
A hydration-layered structure of buserite-type manganese oxide (Mg–buserite) was successfully synthesized by an ion exchange method. The as-prepared Mg–buserite possesses a large basal spacing of 10 Å, and contains Mg2+ ions and two sheets of water molecules in the interlayer region. The supercapacitive behaviors of Mg–buserite were systematically investigated by cyclic voltammetry (CV), galvanostatic charge–discharge (CD) experiments and electrochemical impedance spectroscopy (EIS). The results showed that the specific capacitance of the Mg–buserite electrode sharply increased during the initial 500 cycles and reached a maximum of 164 F g−1 at approximately the 500th cycle at a scan rate of 1 mV s−1, and then it remained an almost constant value and decreased slightly upon prolonged cycling. After 22,000 cycles, the specific capacitance decreased by approximately 6% of the maximum specific capacitance. The superior capacitive behavior and excellent cycling stability of the as-prepared Mg–buserite are attributed to the large basal spacing, which can accommodate a larger amount of electrolyte cations and provide more favorable pathways for electrolyte cations intercalation and deintercalation. The experimental results demonstrate that Mg–buserite is a promising candidate as an electrode material for supercapacitors.
A commercial proton exchange membrane fuel cell has been fitted with a simple dynamic hydrogen reference electrode (DHE). Single electrode potentials and impedances measured with hydrogen and methanol as the fuel have been critically evaluated. It has been shown that the anode overpotential and impedance can be very significant in hydrogen cells operated at ambient temperature, due to dehydration of the anode. The DHE provides a powerful way of monitoring the hydration state of the membrane and electrodes, so that operating conditions can be adjusted to optimise water management. Individual electrode potentials and impedances are even more important in methanol cells, and can be conveniently measured with the DHE.
Surface free energy and contact angle measurements were conducted with a series of room temperature ionic liquids (RTILs) based on N,N′-alkyl-pyrrolidinium imide. Wetting characteristics of various separators (Celgard® and Separion®) and electrodes (LiCoO2, Li4Ti5O12 and graphite), commonly used in Li-ion batteries, were performed. Initially, the free surface energies were determined for both smooth polymeric materials, constituent of the separators, and pyrrolidinium RTILs. Experimental results and calculations show that (i) N-methyl-N-pentyl pyrrolidinium imide is the most wetting RTIL whatever the separator used, and that (ii) the separator wettability is one of the most important factor to take into account in electrochemical devices.
Bird's nest-like nanographene shell (NGS) encapsulated Si@SiO2 nanoparticles have been prepared by a simple chemical vapor deposition (CVD) method. The shell is comprised of a conformed coating with 4–10 layers of the nanographene, and nanographene spikes with the same thickness grown on the coating surface. The high crystallinity of the shell is demonstrated by XRD, HRTEM and Raman characterization. After SiO2 has been removed, distinctive void space is created between Si core and nested NGS. Statistical estimation from TEM images of 50 Si@void@NGS particles shows that the volume of void space is about 2.82 times of that of Si nanoparticle, sufficient to accommodate volume change from Si to Li15Si4. Evaluation of Si@void@NGS for Li ion anode reveals a specific capacity of 2634 mAh g−1 at a current density of 0.2 A g−1, and an excellent rate and cycling performance. The capacity decreases by 5.2%–2497 mAh g−1 after cycling at current densities of 0.5, 1, 2, 5 10, 20 A g−1. The excellent performance can be attributed to high conductivity and high stability of the shell, which remains intact after repeated cycling.
An understanding of charge dynamics and direct observations of charge generation, transfer and recombination is important to help develop and apply various materials for electronic devices. The authors develop a time-resolved electrostatic force microscopy technique to visually observe charge migration on the nanoscale at a sub-microsecond timeframe.
Advanced surface engineering of nickel-rich cathode materials greatly enhances their structural/thermal stability. However, their application into lithium-ion full-cells still faces challenges, such as the unstable solid electrolyte interphase (SEI) layer on the anode. Herein, we reveal that the degradation of battery cycle life is caused by the release of divalent nickel ions from the LiNi0.8Co0.1Mn0.1O2 cathode and the formation of nickel metal particles on the graphite anode surface, deteriorating the anode SEI layer and its structural integrity. On the basis of this finding, we demonstrate a stable lithium-ion battery by modifying the cathode surface by creating a nanostructured stabilizer with an epitaxial structure that enhances the morphological robustness. During cycling, the nickel defects in the cathode are significantly suppressed, preventing nickel ion crossover. In particular, the anode SEI layer maintains a uniform and dense structure, leading to outstanding cycling stability in the full-cell with a capacity retention of ∼86% after 400 cycles at 25 °C.
Various samples of Ni x Sn y metallic alloys electrodeposited under different current and time regimes have been prepared and tested in lithium cells. The results clearly demonstrate that the electrochemical performance of these intermetallic electrodes greatly depends on the synthesis conditions which in turn reflect on the type of morphology and phase of the various samples. The best electrode cycled with a high capacity delivery, i.e. of the order of 550mAhg−1 and showed an efficient behaviour when used as anode in a lithium ion battery using LiNi0.5Mn1.5O4 as cathode. These results confirm that the electrodeposition is a very promising synthesis tool for monitoring the morphological and phase conditions of Ni x Sn y and that the approach described in this work may be used for further optimizing this intermetallic electrode.
Nanoporous Si was obtained by means of metal-assisted chemical etching. Li ion insertion–extraction was tested by voltammetric and galvanostatic electrochemical cycling in conventional 1 M LiPF6 ethylene carbonate/dimethyl carbonate EC/DMC and in 1 M LiTFSI 1-butyl-1-methyl-pyrrolidinium bis (trifluoromethyl) sulfonylimide [BMP] [TFSI] electrolytes. The nanoporous Si demonstrated high reversibility when cycled in 1 M LiPF6 EC/DMC electrolyte and showed superior activity compared to the non-structured sample. In contrast to the organic carbonate electrolyte, the material cycling in ionic liquid media showed reduced capacity and reversibility of the Li ion exchange. The latter results were discussed in terms of the high viscosity of the ionic liquid and ineffective cathodic passivation of the Si substrate in the ionic liquid-based electrolyte. Scanning electron microscopy imaging showed minor morphological changes due to the large volume change during Li insertion. No signs of crack formation and propagation were detected during the time span of the measurement.
In present work, we developed a simple and green route to fabricate irregular porous network-like NiCo2O4-reduced graphene oxide (rGO) nanocomposite supported on the nickel foam substrates, which was directly used as a binder-free electrode for supercapacitors. The rGO served as a conductive network to facilitate the collection and transportation of electrons during the cycling, improved the conductivity of NiCo2O4, and allowed for a larger specific surface area. The irregular porous structure allowed for the easy diffusion of the electrolyte into the inner region of the electrode. Moreover, the nanocomposite directly fabricated on nickel foam with a better adhesion and avoided the use of polymer binder. This method efficiently reduced ohmic polarization and enhanced the rate capability. As a result, the NiCo2O4-rGO nanocomposite exhibited a specific capacitance of 777.1 F g−1 at 5 A g−1 and about 99.3% of the capacitance retained after 3000 cycles. The capacitance retention was about 87.6% when the current density increased from 1 A g−1 to 20 A g−1. These results indicated that such the irregular porous network-like structure directly synthesized on the substrate could be a promising candidate for high performance energy storage application.
Application of a single layer of graphene to untreated wet mammalian cells enables mass spectrometry imaging of cellular membranes of live cells in solution at subcellular resolution.