batterydata/paper-abstracts huggingface dataset:
This work consists on modifying a layered manganese oxide material with a tytanyl acylate complex through an ion exchange reaction and performing a pillaring process by thermal treatment to induce the formation of titanium oxide nanoparticles in the interlayered space. Atomic absorption spectroscopy (AAS) evidenced a 6.54w% Ti in the material. The XRD patterns showed the typical basal spacing of the birnessite type structure, not significant changes occurred after pillaring. The layer structure is maintained at 175°C, and above this temperature causes the formation of pyrolusite, hausmannite and bixbyite in accordance with thermal events shown in the TGA and DSC analysis. SEM shows the plate like morphology characteristic of this type of materials. The pillared material had more compact morphology. The N2 adsorption-desorption isotherm was type II and shows variation in the hysteresis loops. The BET area increases from 28m2/g to 108m2/g, the micropore area increases from 0.88m2/g to 16.85m2/g, the mesopore size decrease (from 163Å to 136Å) and the micropore size distribution shows a bimodal behavior which indicates a successful pillaring process. The impedance spectroscopy results of the pristine material showed electron transport in bulk and grain boundaries (high frequencies) plus ionic conduction (low frequencies), after pillarization process the electric behavior of the material was mainly due to electrical conduction since the diffusion process associated with ionic conduction was no longer observed. The AC conductivity at high frequency for the pillarized material was three times the conductivity of the raw material. The DC conductivity was thermally activated and it was higher for the pillared material than for the pristine material. There was also experimental evidence of thermally activated dielectric relaxation.
Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li+ salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE8-co-E3SO3Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE8-g-E n SO3Li, n = 2, 3). The highest conductivity at 25°C of 2.0 × 10−7 Scm−1 was obtained for the PAE8-co-E3SO3Li with a salt concentration of EO/Li = 40. The conductivity of PAE8-g-E3SO3Li is lower than that of PAE8-co-E3SO3Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li+. The addition of 50wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE8-g-E2SO3Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100μAcm−2 at 85°C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer.
Well-distributed, nano-sized and amorphous or crystalized NaTi2(PO4)3 (NTP) coating layer with high ionic conductivity is successfully introduced onto the surface of LiNi0.6Co0.2Mn0.2O2 (LNCM) particles by a simple and effective mechanical activation method followed by adjusting the reheating temperature appropriately. The promoting influence of NTP coating on the structure stability, cycle life and high rate capability under elevated cut-off voltage has been investigated in-depth. Particularly for the crystalized NTP-coated LNCM, the main reason for the enhanced electrochemical performance can be attributed to the NTP layer with rhombohedral structure providing convenient and low activation barrier diffusion pathways for Li+ ions to insert/extract the interface of electrode/electrolyte. Besides, the NTP-coated layer with stable structure can effectively inhibit the surface side reaction during the long charge/discharge process under high cut-off voltage, which will reduce the harmful insulative by-products. It's worth mentioning that the cyclic stability of crystalized NTP-coated LNCM between 3.0 and 4.6 V is also improved significantly even under the rigorous test environment.
Cerium triflate (Ce(CF3SO3)3) is used as a superoxide radical scavenger in the ether-based liquid electrolyte for the LiO2 batteries. The radical scavenging capability of Ce3+ is evaluated both in potassium superoxide + crown solution and the LiO2 batteries. The chemical analyses further demonstrate cerium ions can effectively slow down the decomposition of electrolyte attacked by superoxide radicals. When the capacity is fixed to 1000 mAh g−1 at a current density of 500 mA g−1, the LiO2 battery with 1M LiTFSI-TEGDME electrolyte begins to drop its discharge voltage rapidly to 2.0 V near 40th cycle while the electrolyte with Ce3+ additives is still above 2.0 V after 88 cycles, demonstrating the cycle life of the LiO2 batteries show remarkably improved compared to the LiO2 batteries without any additive into electrolyte.
Although large ampere hour nickel–metal hydride (Ni–MH) traction batteries are in the stage of being commercialized for electric and hybrid vehicle applications, little is known about their performance characteristics. By using a standard Hg/HgO reference electrode in a commercial Ni–MH battery, we were able to conduct in situ measurements to determine both kinetic and thermodynamic properties of the system, including the characteristics of individual electrodes. Using the galvanostatic intermittent titration technique (GITT), we simultaneously and effectively determined the open-circuit voltage of the battery, the equilibrium electrode potentials, and the diffusion coefficient of proton and hydrogen in the nickel and metal hydride electrode, respectively, as a function of the states of charge (SOC). Using the current-step excitation technique, we found that the internal resistance of the battery primarily comes from the metal hydride electrode, which is greater by one order of magnitude than that of the Ni electrode. The cyclic linear micro-polarization experiments, on the other hand, showed that the charge-transfer resistance of the electrochemical reaction at the metal hydride electrode is about twice larger than that of the Ni counterpart above 20% SOC. In comparison, the internal resistance is an order of magnitude smaller than those of the electrochemical charge-transfer reactions. The micro-polarization technique also allowed us to calculate the exchange current densities of the respective electrode electrochemical reactions and the associated specific exchange current densities. These in situ, simple but detailed, characterizations of the thermodynamic and kinetic properties of the Ni–MH system provided valuable information for better understanding of the battery performance.
The BiF3/AlPO4 composite has been synthesized using the mixture of as-prepared BiF3 and amorphous AlPO4 powder as the starting materials by solid state method. The structure and morphology of AlPO4 and BiF3/AlPO4 composite have been characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The electrochemical performance of BiF3/AlPO4 composite has been studied by galvanostatic charge/discharge, cyclic voltammetry (CV) measurements. The results show that the as-prepared AlPO4 is amorphous, and the addition of amorphous AlPO4 does not change the bulk structure of BiF3, but AlPO4 is only coated on the surface of BiF3 forming the BiF3/AlPO4 composite. Electrochemical measurements in the voltage range of 1.5–4.5 V reveal that the addition of amorphous AlPO4 can effectively reduce the effect of solid electrolyte interface (SEI) and markedly improve the electrochemical performance of BiF3 in the EC:DMC electrolyte. And the BiF3/AlPO4 composite delivers an initial discharge capacity of 271.5 mAh g−1 and a reversible capacity of 209.1 mAh g−1 at a current density of 30 mA g−1. Furthermore, the BiF3/AlPO4 composite also exhibits enhanced rate capability and acceptable cycle performance.
The present study investigated additional deficits beyond the documented problems of phonological processing in developmental dyslexia, concerning possible perceptual–motor automaticity and working memory (WM) ability. The participants consisted of 30 normal and 30 dyslexic children. A battery of intelligence, psychopathology, RAN-digit, short term memory (STM) and WM were administered to both groups, in addition to phonological ability and reading comprehension tests. Dyslexic children obtained significantly lower phonological awareness, RAN-digit speed, STM and WM scores. Working memory but not RANdigit predicted reading ability beyond phonological awareness. The findings are discussed based on the existing heterogeneity within dyslexia.
Core–shell Cu@Cu6Sn5 nanowires with three-dimensional structure have been successfully synthesized via an electrodeposition process, using Cu(OH)2 nanorods prepared by anodization as the substrate. Different temperatures have been employed to heat-treat Sn–Cu composites. After heat-treated at 80°C, strong adherence of the active material Cu6Sn5 to the current collector is achieved, and the crystal structure becomes more stable, thus delivering best cycling performance of 0.162mAhcm−2 after 200 cycles at 1C. Furthermore, superior rate capability (as high as 20C) is also obtained.
Recent successes with disordered Li-excess materials and applications of percolation theory have highlighted cation-disordered oxides as high capacity and energy density cathode materials. In this work, we present a new class of high capacity cation-disordered oxides, lithium-excess nickel titanium molybdenum oxides, which deliver capacities up to 250 mA h g−1. These materials were designed from percolation theory which predicts lithium diffusion to become facile in cation-disordered oxides as the lithium-excess level increases (x > 1.09 in LixTM2−xO2). The reversible capacity and rate capability in these compounds are shown to considerably improve with lithium excess. In particular, Li1.2Ni1/3Ti1/3Mo2/15O2 delivers up to 250 mA h g−1 and 750 W h kg−1 (∼3080 W h l−1) at 10 mA g−1. Combining in situ X-ray diffraction, X-ray absorption near edge spectroscopy, electron energy loss spectroscopy, and electrochemistry, we propose that first charging Li1.2Ni1/3Ti1/3Mo2/15O2 to 4.8 V occurs with Ni2+/Ni∼3+ oxidation, oxygen loss, and oxygen oxidation in this sequence, after which Mo6+ and Ti4+ can be reduced upon discharge. Furthermore, we discuss how oxygen loss with lattice densification can affect lithium diffusion in the material by decreasing the Li-excess level. From this understanding, strategies for further improvements are proposed, setting new guidelines for the design of high performance cation-disordered oxides for rechargeable lithium batteries.
Objectives To conduct a pilot study to evaluate the predictive value of the Montreal Cognitive Assessment test (MoCA) and a brief test of multiple object tracking (MOT) relative to other tests of cognition and attention in identifying at-risk older drivers, and to determine which combination of tests provided the best overall prediction. Methods Forty-seven currently licensed drivers (58–95 years), primarily from a clinical driving evaluation program, participated. Their performance was measured on: (1) a screening test battery, comprising MoCA, MOT, Mini-Mental State Examination (MMSE), Trail-Making Test, visual acuity, contrast sensitivity, and Useful Field of View (UFOV) and (2) a standardized road test. Results Eighteen participants were rated at-risk on the road test. UFOV subtest 2 was the best single predictor with an area under the curve (AUC) of .84. Neither MoCA nor MOT was a better predictor of the at-risk outcome than either MMSE or UFOV, respectively. The best four-test combination (MMSE, UFOV subtest 2, visual acuity and contrast sensitivity) was able to identify at-risk drivers with 95% specificity and 80% sensitivity (.91 AUC). Conclusions Although the best four-test combination was much better than a single test in identifying at-risk drivers, there is still much work to do in this field to establish test batteries that have both high sensitivity and specificity.
The gel electrolyte is a key factor affecting the performance of lead-acid batteries. Two conventional gelators, colloidal and fumed silica, are investigated. A novel gel electrolyte is prepared by mixing the gelators with sulphuric acid. The physical property testing demonstrates that the mixed gel electrolyte is more mobile, has a longer gelling time, greater stability and a better crosslinking structure than its counterparts as compared with any single gelling agent. The electrochemical properties indicate that the mixed gel electrolyte can suppress the oxygen evolution reaction, reduce the resistance to charge transfer at open circuit potential, increase the initial capacity, demonstrating that it is a promising gel electrolyte for lead acid batteries.
Despite great efforts worldwide to evaluate the effects of endocrine-disrupting compounds (EDCs) in fish, there is little information available about the interactions of EDCs with the disruption of the sexual endocrine axis in fish species with matrotrophic viviparity and intraluminal gestation. To understand these interactions, six sampling campaigns were performed within a period of 1 year in two lakes with different degrees of pollution. A battery of biomarkers of the oestrogenic response was assessed in the liver [vitellogenin, CYP 1A1, epoxide hydrolase activity, and metallothioneins (MT)] and MT in the head of Girardinichthys viviparus. Linear correlation analysis and canonical correspondence analysis were performed to explore the relationship between the oestrogenic response with EDCs and with metals. The biomarker responses were assessed using the water content of EDCs (oestrone, 17-β-oestradiol, oestriol, 17-α-ethinyl oestradiol, total phenols, bisphenol A, nonyl phenol, octyl phenol), as well as the PAHs indene[1,2,3-c,d]pyrene, naphthalene, pyrene, benzo[a]anthracene, benzo[k]fluoranthene and benzo[a]pyrene) and metals (Cu, Fe, Mn, Pb and Zn). Greater disruption of the sexual endocrine axis occurred in fish of both sexes inhabiting the polluted lake whose effects were apparently influenced by CYP 1A1 activity and by 17-α-ethinyl oestradiol. In addition, non-estrogenic mechanisms in the hypothalamus and pituitary glands in male fish were observed, elicited by endogenous levels and the water concentration of Pb. In contrast, in females from the less polluted lake, VTG induction was related to exogenous oestrogens. The disruption of the hypothalamic–pituitary–gonadal axis is a complex process influenced by both endogenous and exogenous factors and contributes to male feminisation by exposure to EDCs.
The dry combustible fraction of source-sorted household waste, including material that would otherwise be recycled, was mixed with the energy crop reed canary-grass (Phalaris arundinacea L.), and combusted as briquettes in 150 and 600kW biofuel-boilers without advanced cleaning systems. The source-sorted waste was further sorted and characterized according to its material and chemical contents. The bulk of the waste’s chlorine content came from the non-package plastic fraction, whereas 90–95% of ∑PCDD/F (74–90% of WHO-TEQ) originated from the textile fraction. The sources of the dioxins in the waste fractions are discussed. The balance of dioxin levels was negative, i.e., the amounts of dioxins output in the flue gas were lower than those input in the fuel, except when there were operational disturbances in the combustion. In one of the combustion trials the total levels of dioxins in the flue-gas and ashes were also lower than the input levels. The use of additional cleaning equipment will be needed to ensure that emissions of dioxins and hydrochloric acid will be below legal limits.
Although Li-based batteries have established a dominant role in the current energy-storage landscape, post-Li chemistries (for example, Al or Zn) are emerging as promising candidates for next-generation rechargeable batteries. Electrochemical cells using Al or Zn metal as the negative electrode are of interest for their potential low cost, intrinsic safety and sustainability. Presently, such cells are considered impractical because the reversibility of the metal anode is poor and the amount of charge stored is miniscule. Here we report that electrodes designed to promote strong oxygen-mediated chemical bonding between Al deposits and the substrate enable a fine control of deposition morphology and provide exceptional reversibility (99.6–99.8%). The reversibility is sustained over unusually long cycling times (>3,600 hours) and at areal capacities up to two orders of magnitude higher than previously reported values. We show that these traits result from the elimination of fragile electron transport pathways, and the non-planar deposition of Al via specific metal–substrate chemical bonding.
Nanostructured λ-MnO2 and α-MnO2 are investigated for use in rechargeable Mg ion battery (MIB) cathodes. In order to prepare nanosized particles, the manganese dioxides are prepared by the acid treatment of spinel MgMn2O4 synthesized using the Pechini method. X-ray diffraction analysis indicates that the resulting MnO2 consists of multiple phases, λ-MnO2, α-MnO2, and β-MnO2, depending on the leaching time in acid solution. Upon the first charge–discharge cycle in acetonitrile electrolyte, the λ-MnO2 based electrode shows larger reversible capacity of ∼330 mAh g−1 compared to an electrode containing a large amount of α-MnO2. This enhanced capacity is associated with the facile charge-transfer reaction of Mg ions at the MnO2/electrolyte interfaces. The capacity fading of MnO2 in different electrolytes is also discussed in terms of the formation of a surface layer at the electrode/electrolyte interface during the charging process.
Self-supported and flexible highly porous carbon nanofibers (HPCNFs) were prepared by electrospinning method combined with a post-two-step carbonization process. By introduction of air into the Ar flow during carbonization, carbon nanofibers were partially burnt off and a large number of micro/mesopores were created. As effective lithium storage units, the porous structure plays an important role in enhancing the electrochemical performances. The HPCNFs delivers a reversible capacity as high as 1780mAhg−1 after 40 cycles at 50mAg−1 and ultralong cycle life (1550mAhg−1 after 600 cycles at 500mAg−1). Even cycled at 25Ag−1, it still displays a very high capacity of 200mAhg−1. The outstanding electrochemical and mechanical properties of HPCNFs are attributed to the novel structure: pores provide good access of the electrolyte to the electrode surface and facilitate fast charge transfer across the electrode/electrolyte interface. 3D interconnected networks decrease the contact resistance and improve electrical conductivity of the overall electrode, which enhance electron transport rate. Therefore, this novel carbon material holds great promise for potential applications in energy-related technological and flexible electrodes for next generation LIBs.
The vanadium(IV) ion is found to form the [VO(SO4)(H2O)4]·H2O complex, as well as the dimer, [VO(H2O)3]2(μ-SO4)2, in concentrated H2SO4 media. Their formation mechanisms were investigated by UV–Visible spectroscopy (UV–Vis), Raman spectroscopy, X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). UV–Vis spectroscopy study showed that [VO(SO4)(H2O)4]·H2O concentration in H2SO4 solution was proportional to concentrations of VO2+ and SO4 2−. The increased deviation from the near centrosymmetry of the octahedral complexes is due to the replacement of an equatorial water oxygen in [VO(H2O)5]SO4 by a sulfate oxygen in [VO(SO4)(H2O)4]·H2O. The dimer shows symmetrical structure, which correlates very well with non-activity in UV–Vis spectroscopic analysis. Structural information on both vanadium(IV) species can be confirmed by Raman and XRD measurements of crystals from the supersaturated solution of VOSO4 in 1M, 6M and 12M sulfuric acid. A solution of vanadium(IV) (0.05M) in 12M H2SO4, in which the vanadium(IV) species is [VO(H2O)3]2(μ-SO4)2, exhibits a reversible redox behavior near 1.14V (vs. SCE) on the carbon paper electrode.
Symmetric cells comprising either a pair of positive (sulfur), blocking or negative (lithium) electrodes were investigated by means of electrochemical impedance spectroscopy, to break down the complexity of the lithium–sulfur chemistry and to understand how the individual cell components influence the transport properties of a full cell. We thoroughly analyzed the ageing of the negative electrode (lithium metal) interface under open circuit conditions as a function of the nature of species present in the electrolyte, including the influence of dissolved binder and/or long-chain polysulfides. In a similar manner, we investigated the positive electrode interface. Herein, the objective was to understand the impact of an individual electrode component on the impedance response of the symmetric cell, and, more importantly, to discern the role of the sulfur in charge transfer reaction(s).
To optimize the electrolyte is one of the most important directions to take in order to improve the Li/S battery in terms of performance – especially cell cyclability, rate capability, safety, and life-span. In this review we examine the state of the art for different choices of electrolytes; concepts, design, and materials, and how the resulting chemical and physical properties of the electrolyte affect the overall Li/S battery performance. The objective is to create an overall assessment of electrolytes in use at present and to provide a thorough basis for rational selection of future electrolytes for Li/S batteries.
Due to the asymptotic structure of the black hole solution, there are two different thermodynamic schemes for the charged Banados–Teitelboim–Zanelli (BTZ) black hole. In one scheme, the charged BTZ black hole is super-entropic, while in the other, it is not (the reverse isoperimetric inequality is saturated). In this paper, we investigate the thermodynamic curvature of the charged BTZ black hole in different coordinate spaces. We find that in both schemes, the thermodynamic curvature is always positive, which may be related to the information of repulsive interaction between black hole molecules for the charged BTZ black hole if we accept an empirical relationship between the thermodynamic curvature and interaction of a system. More importantly, we provide a diagnosis for the discrimination of the two schemes from the point of view of the thermodynamics geometry. For the charged BTZ black hole, when the reverse isoperimetric inequality is saturated, the thermodynamic curvature of an extreme black hole tends to be infinity, while when the reverse isoperimetric inequality is violated, the thermodynamic curvature of the extreme black hole goes to a finite value.