batterydata/paper-abstracts huggingface dataset:
Nanotechnology produces hybrids with superior properties than its individual constituents. Here MWCNT@TiO2 composites have been synthesized by controlled hydrolysis of titanium isopropoxide over MWCNT, to be incorporated into Li-ion battery electrodes. Outstanding rate capability of the coated nanotubes is observed in comparison to pristine TiO2. Specific storage capacity as high as 250 mAh g−1 is achieved for the nanocomposite electrode which doubles that encountered for TiO2-based anodes. The mechanism explaining the enhancement in power performance has been revealed by means of electrochemical impedance methods. Although both pristine TiO2 and MWCNT@TiO2 would potentially exhibit comparable specific capacity, the charge transfer resistance for the latter is reduced by a factor 10, implying a key role of MWCNTs to favor the interfacial Li+ ion intake from the electrolyte. MWCNT efficiently provides electrons to the nanostructure through the Ti–C bond which assists the Li+ ion incorporation. These findings provide access to the detailed lithiation kinetics of a broad class of nanocomposites for battery applications.
NMR spectroscopy continues to evolve, with publications in 2009 providing an eclectic collection of applications, advances and incremental improvements. This article covers rapid acquisition methods, DNP, SQUID, new liquid-state methods, “easy” and “difficult” solid-state methods, and computational aspects of NMR spectroscopy. A significant landmark was achieved in 2009, with the commercial release of the 1000 MHz (1 GHz, 23.4 T) NMR magnet. Also, despite the headline grabbing 1 GHz magnet, there remains significant interest in Earth-field (54 μT) NMR. 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.
New Zealand has one of the highest asthma rates in the world, frequently linked to the quality of housing. A confirmed causal factor for asthma is the dust mite allergen, with environmental factors such as temperature and relative humidity (RH) linked to the proliferation of dust mites. Whilst significant research has been undertaken into the habitat and ecology of dust mites, little research has been conducted comparing different categories of housing quality in relation to dust mites.
Non-aqueous gel polymer electrolytes (GPEs) consisting of 30% poly(methyl methacrylate)-grafted natural rubber (MG30), lithium triflate (LiTf), and ethylene carbonate (EC) dissolved in tetrahydrofuran are examined as electrolytes for lithium polymer batteries. The AC impedance technique is employed at room and elevated temperatures in the frequency range between 0.1 kHz and 1.0 MHz to optimize the conductivity of MG30–LiTf samples. The membrane containing 35 wt.% of LiTf is found to exhibit the highest ionic conductivity. The introduction of EC resulted in increased ionic conductivity of up to 8.95 × 10−3 S cm−1 at room temperature for the composition MG30(15):LiTf(9):EC(76). The temperature dependence conductivity for all systems studied is of the Vogel–Tamman–Fulcher type. Attenuated total reflectance-Fourier transformed infrared spectroscopic analysis suggested that EC penetrated between the polymer chains without perturbing the complexation that occurred between the polymer and lithium salt. The Li/Li+ interface stability is established to withstand voltages greater than 4.2 V. A lithium polymer half-cell is successfully fabricated using MG30-based GPE and the cell with configuration of Li/MG30:LiTf:EC/LiCoO2 is found to show good cycling efficiency at room temperature.
The electrodeposition of zinc from sulphate-tartrate baths on a vitreous carbon electrode has been studied. The influence of the tartrate ion on the reduction kinetics of Zn(II) metal ion, and on the mechanism of the electrodeposition process, has been investigated using potentiodynamic and potentiostatic electrochemical techniques and scanning electron microscopy. The voltammetric analysis has shown that the presence of tartrate species in the sulphate bath shifts the reduction potential of Zn(II) to more positive values. A set of equilibria have been proposed to represent the electrochemical process and the influence of pH. From the analysis of the chronoamperometric transients and the SEM images, an instantaneous nucleation with 2D growth at the initial stages has been proposed, and a nucleus density of the order of 109 cm−2 has been calculated from both techniques. In order to elucidate the correct mechanism of the electrodeposition process the results obtained from chronoamperometric transients must be corroborated by those of direct observation using microscopic techniques.
With its stability against Li and good ionic conductivity, Li7La3Zr2O12 (LLZO) has emerged as a promising electrolyte material for lithium-based solid-state batteries (SSBs). Thin layers of solid electrolyte are needed to enable the practical use of SSBs. We report the first deposition of Li-conductive crystalline Ta-doped LLZO thin films on MgO (100) substrates via pulsed laser deposition. Further, we investigate the impact of laser fluence, deposition temperature (in the 50 °C–700 °C range), and post-deposition annealing on the structural, compositional, and transport properties of the film. We analyze the structure of the deposited films via grazing incident X-ray diffraction, their morphology via scanning electron microscopy, and the composition via depth profiling X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. The Li ionic conductivity is investigated via electrochemical impedance spectroscopy. Contrary to previous reports for LLZO films, the crystalline Ta-doped films presents a pure cubic LLZO structure for deposition temperatures as low as 50 °C, with resulting conductivities not significantly influenced by the temperature deposition. Instead, the laser fluence has a major effect on the growth rate of the thin films.
In the first part of this work [1] a field operational test (FOT) on micro-HEVs (hybrid electric vehicles) and conventional vehicles was introduced. Valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology and flooded batteries were applied. The FOT data were analyzed by kernel density estimation. In this publication multiple regression analysis is applied to the same data. Square regression models without interdependencies are used. Hereby, capacity loss serves as dependent parameter and several battery-related and vehicle-related parameters as independent variables. Battery temperature is found to be the most critical parameter. It is proven that flooded batteries operated in the conventional power system (CPS) degrade faster than VRLA–AGM batteries in the micro-hybrid power system (MHPS). A smaller number of FOT batteries were applied in a vehicle-assigned test design where the test battery is repeatedly mounted in a unique test vehicle. Thus, vehicle category and specific driving profiles can be taken into account in multiple regression. Both parameters have only secondary influence on battery degradation, instead, extended vehicle rest time linked to low mileage performance is more serious. A tear-down analysis was accomplished for selected VRLA–AGM batteries operated in the MHPS. Clear indications are found that pSoC-operation with periodically fully charging the battery (refresh charging) does not result in sulphation of the negative electrode. Instead, the batteries show corrosion of the positive grids and weak adhesion of the positive active mass.
MoS2 nanosheets with conformal carbon coating are achieved via a facile, chemical vapor deposition process, employing ethanol vapor as carbon source. The uniform carbon layers are semi-graphitized, which facilitate kinetics for electron and ion transfer, accommodate volume variation of MoS2, and relieve dissolution of polysulfide during repeated discharge/charge cycles. As anode materials for sodium-ion batteries, the optimized carbon coated MoS2 nanosheets show stable reversible capacity of ∼500mAhg−1 for 100 cycles at 0.1Ag−1, and maintain 351.6mAhg−1 after 200 cycles even at 1Ag−1. Furthermore, the enhanced electron transfer, and the stabilized structure are verified through electrochemical impedance spectroscopy, cyclic voltammetry, as well as scanning electron microscopy. Our results show that the carbon coating by chemical vapor deposition is efficient and promising to improve the reversible Na+ storage performance of anode materials.
The aging of graphite anodes in prismatic lithium ion cells during a low temperature pulse charging regime was studied by electrical tests and post-mortem analysis. The capacity decrease and impedance increase mainly occurs in the beginning of cycling and lithium plating was identified as the major aging mechanism. The degradation and the local states of charge show an inhomogeneous distribution over the anode, which is confirmed from spatially resolved XRD studies and SEM combined with EDX performed on electrode cross sections. Comparing a charged cell with a discharged cell reveals that ca. 1/3 of the lithium is plated reversibly at the given SOH of 60%. It is proposed that high charge rates at low temperatures induce inhomogeneities of temperature and anode utilization resulting in inhomogeneous aging effects that accumulate over lifetime.
A series of single-crystalline alkaline earth metal germanate nanowires, including calcium germanate (Ca2Ge7O16), strontium germanate (SrGe4O9) and barium germanate (BaGe4O9) are synthesized by a low-cost, large-scale hydrothermal route. These one-dimensional germanate nanowires represent a new class of anode material for use as Li-ion battery materials with superb lithium storage capacities, cycle performance and rate performance.
This paper has a twofold purpose. First, to characterize the sustainability of the European wood manufacturing industry. In this way, a ranking of the European countries analyzed in terms of sustainability is established. To undertake this task the sustainability of each country is defined by using several indicators of diverse nature (economic, environmental and social). These indicators are aggregated into a composite or synthetic index with the help of a binary goal programming model. In this way, a ranking according to the sustainability of the wood manufacturing industry in the European countries studied is obtained. The second step in the research consists of explaining the causes behind the level of sustainability of each country. This task is carried out by taking the composite indexes of sustainability as endogenous variables and a tentative set of economic, environmental and social variables as explanatory variables. The link between endogenous and exogenous variables is made with the help of econometric models.
India is used as a case study in reviewing the application of receptor models for source apportionment. India has high concentrations of airborne particulate matter, and the application of effective abatement measures is a high priority, and demands confidence in the results of source apportionment studies. The many studies conducted are reviewed, and reveal a very wide range of conclusions, even for the same city. To some degree these divergences may be the result of using different sampling locations and/or seasons, but to a large extent differences probably arise from methodological weaknesses. The assignment of factors from multivariate receptor models to specific source categories is in many cases highly questionable as factors often include combinations of chemical constituents that are of low plausibility. This ambiguity in terms of presence of tracer elements may be the result of genuine collinearity of diverse sources, or more probably arises from methodological problems. Few studies have used either organic molecular markers or chemical mass balance (CMB) models, and there is a shortage of data on locally-derived emission source profiles, although recent work has begun to remedy this weakness. The conclusions include a number of recommendations for use in design of future studies.
Although numerous published reports have demonstrated the beneficial effects of transcranial direct-current stimulation (tDCS) on task performance, fundamental questions remain regarding the optimal electrode configuration on the scalp. Moreover, it is expected that lesioned brain tissue will influence current flow and should therefore be considered (and perhaps leveraged) in the design of individualized tDCS therapies for stroke. The current report demonstrates how different electrode configurations influence the flow of electrical current through brain tissue in a patient who responded positively to a tDCS treatment targeting aphasia. The patient, a 60-year-old man, sustained a left hemisphere ischemic stroke (lesion size = 87.42 mL) 64 months before his participation. In this study, we present results from the first high-resolution (1 mm3) model of tDCS in a brain with considerable stroke-related damage; the model was individualized for the patient who received anodal tDCS to his left frontal cortex with the reference cathode electrode placed on his right shoulder. We modeled the resulting brain current flow and also considered three additional reference electrode positions: right mastoid, right orbitofrontal cortex, and a “mirror” configuration with the anode over the undamaged right cortex. Our results demonstrate the profound effect of lesioned tissue on resulting current flow and the ability to modulate current pattern through the brain, including perilesional regions, through electrode montage design. The complexity of brain current flow modulation by detailed normal and pathologic anatomy suggest: (1) That computational models are critical for the rational interpretation and design of individualized tDCS stroke-therapy; and (2) These models must accurately reproduce head anatomy as shown here.
In this work we evaluate the safety characteristics of an advanced Sn–C/EC:PC 1:1, LiPF6 PVdF gel electrolyte (GPE)/LiNi0.5Mn1.5O4 lithium ion polymer battery. The tests are performed by using a complex analysis that combines Differential Scanning Calorimetry (DSC) Thermal Gravimetric Analysis (TGA), and Mass Spectrometry (MS). This is a very convenient tool since it detects eventual thermal decomposition processes and provides information on the nature of their products. The results of the DSC–TGA–MS analysis are here reported and discussed. They demonstrate that both the anode and the cathode sides of the battery may stand temperatures up to ca. 200°C without undergoing thermal decomposition. This is a convincing evidence that the Sn–C/LiNi0.5Mn1.5O4 lithium ion polymer battery is safe.
We report a case of aortoesophageal fistula (AEF) caused by a fish bone that had a successful outcome. Aortoesophageal fistula is a rare complication of foreign body ingestion from which few patients survive. Over one hundred cases of AEF secondary to foreign body ingestion have been documented but only seven, including our case, have survived over 12 months. Treatment involved stabilising the patient with a Sengstaken-Blakemore tube and insertion of a thoracic aortic endovascular stent-graft. Unfortunately the stent became infected and definitive open surgical repair involved removing the stent, replacing the aorta with a homograft and coverage with a left trapezius flap while under deep hypothermic arrest.
PURPOSE: Animal research and cross-sectional studies suggest that serum lipid concentrations may influence cognitive function, mood, and behavior, but few clinical trials have studied these effects. SUBJECTS AND METHODS: In this double-blind investigation, 209 generally healthy adults with a serum low-density-lipoprotein (LDL) cholesterol level of 160 mg/dL or higher were randomly assigned to 6-month treatment with lovastatin (20 mg) or placebo. Assessments of neuropsychological performance, depression, hostility, and quality of life were conducted at baseline and at the end of the treatment period. Summary effect sizes were estimated as z scores on a standard deviation (SD) scale. RESULTS: Placebo-treated subjects improved between baseline and posttreatment periods on neuropsychological tests in all five performance domains, consistent with the effects of practice on test performance (all P <0.04), whereas those treated with lovastatin improved only on tests of memory recall (P = 0.03). Comparisons of the changes in performance between placebo- and lovastatin-treated subjects revealed small, but statistically significant, differences for tests of attention (z score = 0.18; 95% confidence interval (CI), 0.06 to 0.31; P = 0.005) and psychomotor speed (z score = 0.17; 95% CI, 0.05 to 0.28; P = 0.004) that were consistent with greater improvement in the placebo group. Psychological well-being, as measured several ways, was not affected by lovastatin. CONCLUSION: Treatment of hypercholesterolemia with lovastatin did not cause psychological distress or substantially alter cognitive function. Treatment did result in small performance decrements on neuropsychological tests of attention and psychomotor speed, the clinical importance of which is uncertain.
The efficient reversible formation of discharge products for Li-O2 batteries is still challenging. Meanwhile, the question of the nature of the discharge products and their decomposition mechanism are still remain. Implanting oxygen vacancies on the metal oxides can create negative-charge surface to provide strong adsorption of active oxygen and at the same time, the exposed metal sites can serve as an efficient substrate for decomposed reaction of discharge products. In this work, we apply the graphene-like MoO3 ultrathin nanosheets as a matrix. By controlling the reduction time, the MoO3 nanosheets with different concentration of oxygen vacancy are obtained. Experimental results reveal that the MoO3 nanosheets with the high-concentration oxygen vacancies can significantly decrease the overpotential and get enhanced electrochemical response, namely, a low overpotential of ~0.5V can be delivered with ultra-stable cycles (over 60 cycles). Moreover, the Li-O2 batteries demonstrate an interesting four-step discharge and charge process. X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy and electron energy-loss spectroscopy analyses are carried out for the four typical states of the cathode to reveal the reaction mechanism for the unique electrochemical behavior.
The performance of mixed bi-material electrodes composed of the battery material, LiMn2O4, and the electrochemical capacitor material, activated carbon, for hybrid electrochemical energy storage devices is investigated by galvanostatic charge/discharge and pulsed discharge experiments. Both, a high and a low conductivity lithium-containing electrolyte are used. The specific charge of the bi-material electrode is the linear combination of the specific charges of LiMn2O4 and activated carbon according to the electrode composition at low discharge rates. Thus, the specific charge of the bi-material electrode falls between the specific charge of the activated carbon electrode and the LiMn2O4 battery electrode. The bi-material electrodes have better rate capability than the LiMn2O4 battery electrode. For high current pulsed applications the bi-material electrodes typically outperform both the battery and the capacitor electrode.
Cathodic performance of six different VOPO4 phases for Li ion rechargeable battery was investigated. It was found that VOPO4 exhibits a high flat discharge potential of 3.7 V for Li ion electrochemical intercalation and de-intercalation excepting for β- and ε-types. On the other hand, slightly higher flat discharge potential of 3.9 and 3.8 V was observed for β- and ε-types. Capacity for Li intercalation is strongly related with the crystal structure of VOPO4. In particular, δ-phase exhibits the largest reversible capacity of ca. 130 mAh/g among the examined VOPO4. High capacity for Li intercalation in δ-phase VOPO4 hardly decreased over 30 times of charge and discharge cycles. Although the reversible capacity decreased with increasing the current density for charge and discharge, large capacity of 80 mAh/g was still sustained at 0.4 mA/cm2 for δ-type VOPO4.
We adapted the emulsion drying method to obtain highly crystalline spinel LiMn2O4 phase using LiNO3 and Mn(NO3)2·6H2O as starting materials. The emulsion-dried powders were calcined at various temperatures for 24 h in air, and their crystalline phases were identified as a cubic spinel structure with the space group Fd3m by X-ray diffraction study. The initial discharge capacity of the samples calcined at 650°C, 750°C and 850°C were approximately 120 mA h/g, irrespective of calcination temperature. However, their capacity fadings were significantly dependent on the calcination temperature. To investigate the structural changes in the oxide cathode, XRD experiment was carried out as functions of lithium content and charge–discharge cycling number. Through the SEM observation, it was found that particles were disrupted, and the degree of disruption increased with lithium content and cycling.
Magnesium batteries are energy storage systems that potentially offer high energy density owing to their ability to employ magnesium metal as a negative electrode. Their development, however, has been thwarted by a paucity of functional positive electrode materials after the seminal discovery of the Mo6S8 Chevrel phase over 15 years ago. Herein, we report the second such material – a thiospinel – and demonstrate fully reversible Mg2+ electrochemical cycling vs. a Mg anode, which is complemented by diffraction and first principles calculations. The capacity approaches 80% of the theoretical value at a practical rate (C/5) at 60 °C, and yields a specific energy of 230 Wh kg−1, twice that of the Chevrel benchmark. Our results emphasize the advantage in employing “soft” anions to achieve practical divalent cation mobility.
A liquid Stannum (Sn) anode fuel cell is fabricated by using smooth single crystal Yttria Stabilized Zirconia (YSZ) electrolyte and porous Pt cathode. The cell performance in the battery mode is tested to identify the intrinsic reaction kinetics of the Sn electrochemical oxidation reaction. The cell performance characteristics in the gas fuel mode and carbon fuel mode are experimentally measured to identify limiting steps in different operating modes. The results show that in the battery mode, the SnO2 film formation blocks the transportation path of the liquid Sn and oxygen ions to the reactive interface. In the gas fuel modes, the cell performance operating in the H2 fuel mode is much higher than that in the CO fuel mode which is ascribing to the effective reaction of the formed SnO2 at the reactive interface between electrolyte and anode. In the carbon fuel mode, the carbon black fuel can directly or indirectly reduce part of the SnO2 at the interface between anode and electrolyte. It apparently indicates that the performance improvements of liquid Sn anode direct carbon fuel cell rely on minimizing the effects of formed SnO2 layer and accelerating species transportation processes within the liquid Sn electrode.
In this paper we report a polymer lithium cell using a PVdF-based, gel-type electrolyte formed in-situ during cell assembly. The gel electrolyte formation is monitored prior to cell assembly by electrochemical impedance spectroscopy and by Raman spectroscopy in order to determine the characteristics of the lithium salt diffusion into the gel-membrane. The results show an efficient gel formation and a fast lithium salt diffusion, this finally resulting in an optimized behaviour in a lithium cell using a high voltage spinel-type cathode. We believe that the results here reported may contribute to the enhancement of the safety of lithium batteries.