batterydata/paper-abstracts huggingface dataset:
Humic substances and clay minerals have been studied intensively because of their strong complexation and adsorption capacities. In this work, adsorption of Ni2+ on Na-montmorillonite was studied using batch technique under ambient conditions. Effect of pH, ionic strength, solid content, humic acid (HA), fulvic acid (FA) and the addition sequences of fulvic acid/Ni2+/montmorillonite on Ni2+ adsorption was also investigated. The results indicate that adsorption of Ni2+ on montmorillonite are strongly dependent on pH and ionic strength. The adsorption of Ni2+ is mainly dominated by surface complexation and ion exchange. The adsorption–desorption hysteresis suggests that the adsorption of Ni2+ is irreversible. The thermodynamic parameters (ΔH, ΔS, and ΔG) are calculated from the temperature dependence, and the results suggest that the adsorption reaction is endothermic and spontaneous. The presence of FA and the addition sequences of FA/Ni2+/montmorillonite do not influence the adsorption of Ni2+ on FA bound montmorillonite hybrids. Montmorillonite is a suitable candidate for pre-concentration and solidification of Ni2+ from large volume of solutions.
The passive film on lithium in contact with KOH solution comprises a bilayer structure, consisting of a defective barrier layer and a porous outer layer. Thermodynamic analyses indicate that LiH is the barrier layer phase that forms on lithium in aqueous alkaline solutions under open circuit conditions. Hydrated LiOH, which form as the outer layer of the passive film, also regulates the voltage dependence of the anodic dissolution rate. A steady-state model, based on the Point Defect Model, was developed to account for polarization data, hydrogen evolution data, and the measured faradaic efficiency of the lithium/water system. The steady-state model was extended to account for electrochemical impedance data. The impedance model indicates that some properties (e.g. porosity) of the outer layer depend on the electrolyte concentration, and that the porosity of the outer layer exerts significant influence over the kinetics of electro-dissolution of lithium in aqueous solution.
We have incorporated graphene nanoribbons (GNRs) which are unzipped from multi-wall carbon nanotubes (MWCNT) into silicon–carbon (Si/C) nanofibers, not only to reinforce hybrid Si/C fibers, but also to increase the electrical conductivity and charge transport capability of fibers. We demonstrated that GNRs are promising components for improving the rechargeable Li-ion battery performance due to their unique nanostructures and properties. Water based electrospinning, an easily scalable and environmentally benign process, was utilized to fabricate GNR/Si/C fibers. The resulting fibers exhibited a high reversible capacity of more than 1800mAh/g at 0.5C, and an excellent performance of 1400mAh/g with no capacity fading at a charge/discharge rate of 1C. This outstanding performance should be attributed to the enhanced charge and mass transfer ability of fibers by incorporation of ultrathin, flexible, conductive, and high aspect ratio GNRs. Electrodes made with GNR/Si/C fibers are more durable than ones with Si/C fibers, and do not exhibit dramatic volume and morphology changes after cycling. Moreover, GNR/Si/C fiber anodes were tested in a full-cell configuration where they displayed a steady gravimetric capacity of ca. 1400mAh/ganode for 25 cycles.
One of the challenges in the development of batteries consists of investigating new electrode materials and comprehending the mechanism of lithium uptake. Herein, we report on the first operando measurements of electron magnetism in a battery during cycling. We have succeeded in designing a non-magnetic cell and have investigated the lithiation mechanism of FeSb2, a high energy density anode material. The stepwise increase of the magnetic moment reveals an increase of amorphous Fe nanoparticle size, while Sb undergoes reversible alloying with Li.
In this study, the charge/discharge cycling behaviour of the Ce3+/Ce4+ redox couple in methanesulfonic acid medium on various Pt and Pt-Ir coated titania based substrates was investigated as a function of solution flow rate, temperature and charge/discharge current density using a rotating disk electrode. Although superior performances (in terms of the voltage efficiency, η V) were obtained from the electrodes containing higher amounts of platinum, a deterioration of these electrodes with cycling was evident (after 150 cycles). At rotation rates between 600rpm and 1200rpm, high η V (>90%) could be obtained as long as the current density j applied was below the mass transport limiting current density, j L. For j's above this value, the oxygen evolution reaction occurred with Ce3+ oxidation whereas the Ce4+ reduction was accompanied by oxygen reduction, resulting in lowered η V's. Better stability towards cycling and higher η V's were observed at 60°C compared to 25°C, especially for the etched Pt electrodes. The optimum loading for the Pt substrates was 3gm−2 while for the case of the heat treated samples 10gm−2 of Pt.
Nitric oxide (NO) enhances anti-inflammatory drug action. Through a metabonomics approach termed “NObonomics,” the effects of a prototypic NO donor (organic nitrate)-cyclooxygenase-2 inhibitor hybrid (NO-coxib), NMI-1093, on the NO metabolite status of the circulation and major organs have been profiled in vivo in the rat. An oral anti-inflammatory NMI-1093 bolus elicited acute tissue-, time-, and dose-dependent changes in oxidative and nitroso/nitrosyl NO metabolites. Gastric N-nitrosation and hepatic S-nitrosation and heme nitrosylation emerged as sensitive indices of this NO-coxib's metabolism. Acute NMI-1093-induced nitros(yl)ation correlated positively as a function of nitrate plus nitrite formation across all organs examined, suggesting a unifying in vivo mechanism consequent to NMI-1093 biotransformation that links oxidative and nitros(yl)ative routes of NO chemical biology and thereby may support downstream NO signaling. NMI-1093 depressed erythrocyte nitros(yl)ation, likely by inhibiting cellular carbonic anhydrase and shifting the intracellular balance between nitrogen oxides and carbonates. Glutathione-S-transferase or cytochrome P450 inhibitors also attenuated NMI-1093's NO metabolism in a compartment-selective fashion. Although not itself a NO donor, the des-nitro coxib analog of NMI-1093 influenced basal NO metabolite profiles, implicating a cyclooxygenase–NO synthase interaction in physiological NO regulation. By detailing the global NO metrics of a unique coxib bearing a popular NO-donor pharmacophore (i.e., a nitrate moiety) and defining some critical mechanistic determinants, this study demonstrates how NObonomics can serve as valuable tool in helping elucidate NO systems biology and the effect of NO-donor and non-NO-donating therapeutics thereon.
Tin dioxide (SnO2)-based materials have been considered to be promisingly alternative advanced anode materials for lithium-ion batteries and thus attracted wide attention. So far, the research focus of SnO2-based anode materials is to search and develop effective strategies for overcoming the obstacles, such as rapid capacity fading and poor rate capability, which seriously impede the practical application of SnO2-based electrodes. Herein, we have successfully combined nanoscale SnO2 with 3-dimensional carbon (C) conductivity framework to form a 3-dimensional unparalleled SnO2/C composite constructed by closely interconnected hollow nanospheres with quasi-sandwich structures. When evaluated as anode materials for lithium-ion batteries, the as-prepared SnO2/C composite exhibits improved cycling performance and high rate capability, delivering a high capacity of 576.6 mAh g−1 at 200 mA g−1 even after 500 cycles, and a capacity of 411.7 mAh g−1 even at 5 A g−1 during rate test. The unparalleled 3-dimensional architecture should be responsible for the good electrochemical performance.
Two solvent-free cross-linked polymer electrolytes, a random ethyleneoxide and propyleneoxide copolymer, poly(EO–PO) and a random ethyleneoxide and 2-[2-(2-methoxyethoxy)ethoxy]ethylglycidylether copolymer, poly(EO–GE) doped with LiN(SO2CF3)2 in the ratio 10:1 (polymer oxygen:lithium) were studied using ionic conductivity and 1H, 19F and 7Li NMR measurements in the temperature range of ∼303–353 K. Correlation times for the polymer segmental and the lithium hopping motions of the order of 10−10–10−8 s were determined from the minima in the temperature dependence of the spin–lattice relaxation of the polymers (1H) and lithium (7Li). At the same temperature such motions are faster in the poly(EO–PO) than in the poly(EO–GE) systems and the temperature dependencies of these motions are larger in the poly(EO–PO) system. Since the relaxation behaviors of the anion (19F) were consistent with a single component, the self-diffusion coefficients of the anion were measured using the pulsed-gradient spin-echo (PGSE) NMR method. Although the diffusion data were consistent with a single isotropically diffusing species at each temperature, the measured diffusion coefficients were dependent on Δ (the timescale of the diffusion measurement) but became constant at long Δ values. We surmise that at long Δ the anion has sufficient time to diffuse amongst enough microdomains of the polymer electrolyte system to complete a ‘true average’. During shorter times, the anion appears to diffuse faster. The activation energies obtained from the apparent diffusion coefficients at longer Δ values agreed with those obtained from ionic conductivity measurements for the two polymer electrolytes. The anion diffusion in poly(EO–PO) is faster than in poly(EO–GE) at every temperature.
A review of modern stoichiometric ion exchange theories of solvent extraction separations is presented. These theories are named here as conventional or classic theories. The chapter provides an insight into the basic theories and chemistry of the process. This includes: - the physical and chemical principles and formal expressions of the process (basic solution mechanisms and thermodynamics); - a survey of the effects on the distribution between immiscible [0]phases; - chemistry and other aspects of the extractants, diluents and modifiers, and their interactions in the solvent extraction process; - aspects of the dispersion, and coalescence of phases, changes in parameter values, such as concentration of solutes and solvents, complex formers and other reactants, pH, temperature, etc.
The peripheral complications of diabetes mellitus remain a significant risk to lower-limb morbidity. In New Zealand, risk of diabetes, comorbidity and lower-limb amputation are highly-differential between demographic groups, particularly ethnicity. There is growing and convincing evidence that the use of pedobarography – or plantar pressure measurement – can usefully inform diabetic foot care, particularly with respect to the prevention of re-ulceration among high-risk patients.
This paper presents a novel composite fabrication of aluminum anodes for use in moderate rate Al/Air cells in alkaline media. The polymer composite/particulate aluminum structure allows control of electrolyte contact with the aluminum surfaces during discharge. This ability could lead to improved deliverable energy density and allow the anode discharge characteristics, in some measure, to be tailored to need. A limited first round lab testing of these composite anodes has been carried out. Current capabilities were moderate, ranging up to about 2mA/cm2. Observed cell discharge potentials were mostly above 1V. Delivered energy densities were generally comparable to those of planer anodes of comparable metal weight and alloy. It is of particular significance, however, that the discharge lifetimes of the composite anodes for certain formulations, on a per gram basis, were considerably longer than those of their planer counterparts. Further formulation optimization and fabrication uniformity should lead to improved energy density and lifetime.
To prepare intercalation lithium — transition metal oxide cathode materials for rechargeable lithium batteries, the reactions in the mixtures of the correspondent hydroxides in highly energetic planetary activators, so called ‘soft mechanochemical synthesis’ were studied. The method can be used for direct preparation of final products in a high dispersed and disordered state, as well as for obtaining high reactive precursors yielding final products by the subsequent brief heating at considerably lower temperatures as compared to conventional ceramic method. The as prepared products were analyzed using X-ray diffraction, TG, IRS, XPS, 7Li NMR, EPR, diffuse reflectance spectroscopy, electron microscopy, BET, and electrochemical measurements. The peculiarities of crystal structure, electronic state of transition metal ions and cycling behaviour of materials are discussed. The method as proposed is concluded to be economically effective and ecologically clean.
Semantic memory dysfunction in schizophrenia spectrum disorders has been theoretically linked primarily to formal thought disorder (FTD) and, to a lesser extent, hallucinations. Although past studies have demonstrated associations between FTD and semantic memory dysfunction, the potential influence of hallucinations and other symptoms on this association has not previously been evaluated. We investigated the relationship between semantic dysfunction and levels of schizophrenic symptoms in 75 patients with a DSM-IV diagnosis of schizophrenia/schizoaffective disorder. Symptoms were rated on a 0–5 scale using the Scale for Assessment of Positive Symptoms/Scale for Assessment of Negative Symptoms. Semantic dysfunction was quantified through a semantic/phonological fluency difference score. The vocabulary test from the Shipley Institute of Living Scale was included as a measure of pre-morbid IQ. We hypothesized a relationship between FTD and semantic dysfunction, with an alternative hypothesis being that semantic dysfunction would be related to hallucinations. The measure of semantic dysfunction was significantly correlated with level of hallucinations (r =−.35, p =.002), but not level of FTD (r =.05, p =.67). The relationship between hallucinations and semantic dysfunction remained significant after control for age and verbal intellectual ability, and after controlling for the influence of other symptoms. This finding supports theories linking a breakdown in semantic associative networks to the production of hallucinations, and suggests that past associations between formal thought disorder and semantic dysfunction may have been at least partly driven by differential levels of hallucinations between groups.
In this study, the formation of LiNi0.5Mn1.5O4-δ via thermal conversion of metal nitrates is examined in detail. Furthermore, the nanocasting process and the resulting products of mesoporous LiNi0.5Mn1.5O4-δ are studied and the influence of the template material CMK-8 carbon on the formation process of the oxide is investigated. It was figured out, that the decomposition process of the metal oxide precursors and hence the formation process of pure LiNi0.5Mn1.5O4-δ is strongly affected by the interplay of the different metal nitrates. A significant shift of the decomposition temperatures of the metal nitrates recording to catalytic effects of the intermediate states was observed. Regarding the formation of LiNi0.5Mn1.5O4-δ supported by a carbon matrix (CMK-8 and ‘bulk-CMK’), a decrease of the formation and crystallization temperature of LiNi0.5Mn1.5O4-δ could be determined by XRD investigations. In addition to that, further catalytic accelerations of the decomposition of the precursors and the carbon matrix itself were figured out by applying a mesoporous carbon matrix (CMK-8) these effects were further enhanced.
NMR spectroscopy continues to evolve, with publications in 2011 providing an eclectic collection of applications, advances and incremental improvements. Publications highlights include: DNP in liquids and solids, decoupling effects at high spinning speed in solid-state, results from the 80 kHz spinning-speed 1 mm MAS rotor, enhanced diffusion methods, results from the new 1.0 GHz magnet, an intent to create a 1.3 GHz magnet, results from the 2.6 GHz pulsed-magnet, a cryogen-free MRI, and the use of multiple receivers to acquire multiple experiments within the same pulse sequence. I am indebted to the great and the good whose work has been reported here, all credit is theirs; errors, omissions and blame are all mine.
We have studied the elastic properties of Li–Sn alloys as a function of Li concentration using first principle calculations. Here, we present the anisotropic elastic tensors as well as the orientation-averaged bulk, Young's and shear moduli and the Poisson's ratios for crystalline alloys. Our results demonstrate that crystal anisotropy has a significant effect on the stiffness of the material. We suggest that the bulk, shear and Young's moduli of isotropic Li x Sn alloys decrease monotonically with increasing Li concentration, resulting in elastic softening. On the other hand, highly anisotropic structures of very similar Li contents deviate from linearity indicating either elastic hardening or softening of the material. In addition to the significant role of anisotropy, our results also underscore the importance of including the concentration dependence of the elastic constants in the analysis of deformation during lithiation/delithiation of Sn anodes.
As lithium ion (Li-ion) batteries continue to increase their market share, recycling Li-ion batteries will become mandatory due to limited resources. We have previously demonstrated a new low temperature methodology to separate and synthesize cathode materials from mixed cathode materials. In this study we take used Li-ion batteries from a recycling source and recover active cathode materials, copper, steel, etc. To accomplish this the batteries are shredded and processed to separate the steel, copper and cathode materials; the cathode materials are then leached into solution; the concentrations of nickel, manganese and cobalt ions are adjusted so Ni x Mn y Co z (OH)2 is precipitated. The precipitated product can then be reacted with lithium carbonate to form LiNi x Mn y Co z O2. The results show that the developed recycling process is practical with high recovery efficiencies (∼90%), and 1 ton of Li-ion batteries has the potential to generate $5013 profit margin based on materials balance.
Modelling and numerical simulations play a vital role in the design and optimization of electrochemical energy storage devices. In this study, a general physics-based model is developed to describe Hybrid Asymmetric Capacitors (HACs). A one-dimensional cell is constructed with one faradaic electrode, a separator and a capacitive electrode. The model is validated using a commercial Lithium Ion Capacitor (LIC). Galvanostatic charge and discharge processes are simulated with a maximum mean relative error of 7.8%. This suggest that this simple Ohmic model captures the key electrochemical phenomena occurring inside the LIC cell.
A simple low-cost battery charger based on a saturated controller is proposed for charging of lithium-ion (Li-ion) batteries. When the reference voltage of the closed-loop process is set to 4.2V, the charging process resembles a constant-current and constant-voltage (CC–CV) charging strategy. The charging process can easily be shortened by raising the limit on the saturated controller. Experimental results are included to demonstrate the effectiveness of the charger. It is anticipated that the charger can be a low-cost high-performance replacement of existing Li-ion battery chargers.
Accurate estimations of battery energy and available power capability are of great of importance for realizing an efficient and reliable operation of electric vehicles. To improve the estimation accuracy and reliability for battery state of energy and power capability, a novel model-based joint estimation approach has been proposed against uncertain external operating conditions and internal degradation status of battery cells. Firstly, it proposes a three-dimensional response surface open circuit voltage model to calibrate the estimation inaccuracies of battery state of energy. Secondly, the adaptive unscented Kalman filter (AUKF) is employed to develop a novel model-based joint state estimator for battery state of energy and power capability. The AUKF algorithm utilizes the well-known features of the Kalman filter but employs the method of unscented transform (UT) and adaptive error covariance matching technology to improve the state estimation accuracy. Thirdly, the proposed joint estimator has been verified by a LiFePO4 lithium-ion battery cell under different operating temperatures and aging levels. The result indicates that the estimation errors of battery voltage and state-of-energy are less than 2% even if given a large erroneous initial value, which makes the state of available power capability predict more accurate and reliable for the electric vehicles application.
The height and rate of capillary lift of the electrolyte in the glass-mat separator of a sealed lead-acid battery was investigated. Dependence of the height and rate of rise of sulfuric acid on its density and separator compression degree was established.
Lead dioxide obtained by using various methods in combination with particles ranging from nanometric to micrometric size was tested as positive active material in lead-acid cells. The structural and textural properties of the material were determined by using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM), N2 adsorption measurements and thermogravimetric analysis (TGA). Thin lead dioxide positive electrodes were prepared with obtained materials by spray deposition technique and were subjected to cycling tests. The combination of a small particle size (in the nanometric range) and the presence of water strongly bound to the lattice is essential to ensure a high utilization of the active material and good cycling properties of the positive electrode. Therefore, appropriate nanometric materials provide an effective method for increasing the efficiency of the active material in lead-acid batteries.
Several samples of ion-conducting silver phosphate glasses doped with zinc/cadmium halides are prepared and subjected to X-ray diffraction analysis, transference number measurement, and electrical conductivity studies. The percentage transference numbers of these glasses are found to lie between 98.3 and 99.3, which suggests that the glasses are essentially ionic conductors. The conductivity values range from 1.66×10−2 to 8.66×10−2 Scm−1 at 300°C. Solid-state batteries using these glassy systems as electrolytes with the cell configurations Ag||Ag2OP2O5(20%)Zn/CdX2||(C+I2) and Ag||Ag2OP2O5(20%)Zn/CdX2||(C+I2+electrolyte) (where X is Cl, Br or I) have been fabricated and their discharge characteristics studied. Cells with undoped silver phosphate glasses as electrolytes have also been prepared and studied. The addition of Zn/CdX2 to silver phosphate glass results in a substantial increase in the open-circuit voltage in the order MI2>MBr2>MCl2 (where M is the dopant cation). Cells with Ag||Ag2OP2O5(20%)Zn/CdI2||(C+I2+electrolyte) deliver the best performance.
The LiMn2O4 thin films composed of nanoparticles were synthesized by sintering electrodeposited Mn3O4 precursor on the Au substrate, and the electrochemical properties were investigated. The electrochemical performance was dependent on the film thickness. For the thinner LiMn2O4 films, cycling in the voltage range of 4.3 V–3.4 V resulted in superior rate performance, that is almost 100% of discharge capacity compared with that at 20 times of discharge current density, and good stability without capacity loss until 500 cycles. CV and EIS measurements revealed that LiMn2O4 thin film has good electric contact with substrate and high lithium diffusion coefficient of 10−9–10−11 cm2 s−1 could be obtained.