batterydata/paper-abstracts huggingface dataset:
Aluminium anodising was performed in saturated and unsaturated H2C2O4 solutions and in H2SO4 and saturated H2SO4 +Al2(SO4)3 solutions at similar temperatures, concentrations and current density to reveal the effect of anions and condensed electrolyte nanoparticle micelles formed on pore base and wall surfaces on the mechanism of growth of porous anodic alumina films. Chronopotentiometry and overall kinetics showed that the kinetics and mechanism of growth and nanostructure of films are similar in oxalate and sulphate solutions. But differences also appear, like higher field strength across the barrier layer and much lower pore wall dissolution rate in oxalate solutions. These are attributed to dissimilar kind of anions, smaller amount of incorporated ones and depth of penetration in barrier layer and pore walls during the film growth in oxalate solutions and to their participation in a step of oxide dissolution mechanism that becomes the rate controlling in this case. In saturated solutions the condensed H2C2O4 and Al2(SO4)3 micelles affect the kinetics and mechanism of film growth, more H2C2O4, allowing a better design of structure. Results promote the knowledge on growth mechanism and kinetics of anodic films enabling methods to optimise the structure for their many scientific or technological applications.
The purpose of this study was to examine predictors of neurodevelopmental outcome in very low birth weight children without major impairment at 5 years of age, as well as to identify the contribution of early neurodevelopmental assessment to preterm children's later developmental outcomes. The participants in this study included 126 children who were prematurely born with very low birth weight. Outcomes of the childrens’ later development were measured in tests that factored cognitive function, motor performance, and adaptive behavior. The results indicated that more than 50% of full-scale intelligence and 30% of both motor performance and adaptive behavior at the age of 5 can be explained by four predictors. The four predictors include preterm children's medical complications at birth, maternal education, early motor assessments, and cognitive assessments. Adding each test score obtained in early ages provides additional information to predict children's cognitive, motor, and adaptive behavior at 5 years of age. Manifold assessments conducted in multiple time periods strengthen the predictive values of later developmental outcomes. In addition, the findings of this study indicate that very low birth weight children tend to have lower adaptive behavior at 5 years old. With regard to our findings, we believe that having adaptive function is a reflection of a child's overall integrated abilities. Further study is warranted to increase understanding of this topic, as well as to be able to predict adaptive strengths and weakness and pinpoint limiting factors that may be useful for targeting behaviors in intervention.
In this work, the effects of decomposition products of electrolytes on the thermal stability of bare and TiO2-coated Li1−x Ni0.8Co0.2O2 (1> x ≥0) cathode material have been investigated by means of thermoanalytical, thermokinetic and temperature-programmed desorption–mass spectroscopy (TPD–MS) techniques. It is shown clearly that the decomposition products of the electrolytes such as carboxylates have distinctive effects on the thermal stability of the electrode materials. Firstly, the thermoanalytical and TPD–MS results indicate that surface coating can suppress the amount of oxygen release from the delithiated cathode material. The thermokinetic analytical results show that the reaction of oxygen release (i.e. oxygen loss) from delithiated Li1−x Ni0.8Co0.2O2 material can be promoted by carboxylate salts supported on the electrode surface due to the decrease of initiated activation energy E a of the reaction. Finally, the amount of carboxylate salts and length of carbon chains in carboxylates have different promotional effects on the thermal properties of the electrode materials.
The two polymorphs of lithium cobalt oxide, LiCoO2, present an opportunity to contrast the structural requirements for reversible charge storage (battery function) vs. catalysis of water oxidation/oxygen evolution (OER; 2H2O → O2 + 4H+ + 4e−). Previously, we reported high OER electrocatalytic activity from nanocrystals of the cubic phase vs. poor activity from the layered phase – the archetypal lithium-ion battery cathode. Here we apply transmission electron microscopy, electron diffraction, voltammetry and elemental analysis under OER electrolysis conditions to show that labile Li+ ions partially deintercalate from layered LiCoO2, initiating structural reorganization to the cubic spinel LiCo2O4, in parallel with formation of a more active catalytic phase. Comparison of cubic LiCoO2 (50 nm) to iridium (5 nm) nanoparticles for OER catalysis (commercial benchmark for membrane-based systems) in basic and neutral electrolyte reveals excellent performance in terms of Tafel slope (48 mV dec−1), overpotential (η = ∼420 mV@10 mA cm−2 at pH = 14), faradaic yield (100%) and OER stability (no loss in 14 hours). The inherent OER activity of cubic LiCoO2 and spinel LiCo2O4 is attributed to the presence of [Co4O4]n+ cubane structural units, which provide lower oxidation potential to Co4+ and lower inter-cubane hole mobility. By contrast, the layered phase, which lacks cubane units, exhibits extensive intra-planar hole delocalization which entropically hinders the four electron/hole concerted OER reaction. An essential distinguishing trait of a truly relevant catalyst is efficient continuous operation in a real electrolyzer stack. Initial trials of cubic LiCoO2 in a solid electrolyte alkaline membrane electrolyzer indicate continuous operation for 1000 hours (without failure) at current densities up to 400 mA cm−2 and overpotential lower than proven PGM (platinum group metal) catalysts.
Nanocolumnar composite Cu–Si films were produced as anodes using an oblique angle electron beam co-evaporation method. Two evaporation durations were used to yield different film thicknesses: thin (<250 ± 100 nm) and thick (>400 ± 100 nm). The structural and morphological properties of these Cu–Si films were characterized using X-ray diffraction and scanning electron microcopy. Galvanostatic half-cell electrochemical measurements were conducted over a voltage range of 50 mV–2.5 V using Li as a counter electrode and the Cu–Si films as anodes. The results demonstrated that the thin film has homogeneously distributed nanocolumns and yielded good cyclability upto 100 cycles with high capacity retention; by contrast, the thick film has an inhomogeneous porous structure and exhibited poor cyclability. The reason for the better electrochemical performance of the thin film was determined by X-ray photoelectron spectroscopy (XPS) at different states of charge. Moreover, in-situ electrodilatometric analysis during the galvanostatic test of the thin films measured the ongoing volumetric changes upon cycling.
Lithium intercalation into vanadium pentoxide film electrodes prepared by electrodeposition methods has been investigated in a 1M solution of LiClO4 in propylene carbonate (PC) by employing potentiostatic current transient technique. From the analysis of the current transient experimentally measured, it is proposed that lithium transport through the electrodeposited vanadium pentoxide film electrode is exclusively controlled by the cell impedance. The theoretical current–time relation has been analytically obtained from the solution to the diffusion equation under the assumption of the cell impedance-controlled constraint at the electrolyte/electrode interface. On the basis of the theoretical current transient, the current transient experimentally measured has been analysed to estimate the kinetic parameters governing lithium intercalation such as the cell impedance and the chemical diffusivity of lithium. In particular, the chemical diffusivity of lithium was determined to be 2.1×10−13 to 2.1×10−10 cm2 s−1, and was found to be in good accordance with that obtained from electrochemical impedance spectroscopy.
When assembling lithium-ion cells into functional battery packs, it is common to connect multiple cells in parallel. Here we present experimental and modeling results demonstrating that, when lithium ion cells are connected in parallel and cycled at high rate, matching of internal resistance is important in ensuring long cycle life of the battery pack. Specifically, a 20% difference in cell internal resistance between two cells cycled in parallel can lead to approximately 40% reduction in cycle life when compared to two cells parallel-connected with very similar internal resistance. We show that an internal resistance mismatch leads to high current into each cell during part of the charging cycle. Since capacity fading is strongly dependent on temperature, and hence on charging rate when this rate is sufficiently high, the high current leads to substantially accelerated capacity fade in both cells. A model, based on the formation of a solid-electrolyte interphase, is able to explain the dependence of lifetime on resistance mismatch, and also identifies the importance of random sudden capacity losses.
Three dimensional transient thermal analysis of an air-cooled module that contains prismatic Li-ion cells next to a special kind of aluminum pin fin heat sink whose heights of pin fins increase linearly through the width of the channel in air flow direction was studied for thermal management of Lithium-ion battery pack. The effects of pin fins arrangements, discharge rates, inlet air flow velocities, and inlet air temperatures on the battery were investigated. The results showed that despite of heat sinks with uniform pin fin heights that increase the standard deviation of the temperature field, using this kind of pin fin heat sink compare to the heat sink without pin fins not only decreases the bulk temperature inside the battery, but also decreases the standard deviation of the temperature field inside the battery as well. Increasing the inlet air temperature leads to decreasing the standard deviation of the temperature field while increases the maximum temperature of the battery. Furthermore, increasing the inlet air velocity first increases the standard deviation of the temperature field till reaches to the maximum point, and after that decreases. Also, increasing the inlet air velocity leads to decrease in the maximum temperature of the battery.
Microporous membranes based on poly(vinylidene fluoride–trifluoroethylene) with different NaY zeolite contents were prepared by solvent casting at room temperature for lithium ion battery separator applications. The dependence of the polymer porous microstructure with increasing zeolite content is evaluated as well as the thermal, mechanical and electrical properties of the membrane before and after uptake of the electrolyte solution of 1M LiClO4·3H2O-PC. The zeolite fillers are placed in the walls of the membranes and do not influence significantly the porosity of the membranes. On the other hand, the fillers improve the mechanical strength of polymeric matrix and increase their ionic conductivity. The electrolyte with 16wt.% of zeolites is thermally stable up to 100°C and exhibits the highest conductivity over the studied range of temperatures (2.33×10−6 and 2.51×10−2 Scm−1 at 20 and 120°C, respectively). According to infrared spectroscopic data, major modifications occur in terms of hydrogen bonding interactions at this composition. All porous membranes show good electrochemical stability as determined by cycle voltammetry. The electrochemical stability domain of the sample with 16wt.% zeolite content spans about 5.5V versus Li/Li+.
Fe-substituted LiCoPO4 exhibits greatly improved cycle life relative to LiCoPO4. Whereas, pure LiCoPO4 loses more than half of its discharge capacity at the 10th cycle, the Fe-substituted LiCoPO4 retains about 100% of its discharge capacity at the 10th cycle and about 80% of its capacity at the 500th cycle. It is suggested that improved cycle life results from Fe3+ substitution on the Li and Co sites. The partial substitution of Li+ by Fe3+ and Co2+ by Fe2+ and Fe3+ was evidenced from Rietveld analysis of X-ray powder diffraction data, infrared spectroscopy, X-ray photoelectron spectroscopy and Mössbauer spectroscopy. The majority of the Fe3+ substitutes at the Co2+ site. The composition of Fe-substituted LiCoPO4 is Li0.92Co0.8Fe2+ 0.12Fe3+ 0.08PO4 for a sample of starting composition LiCo0.8Fe0.2PO4.
This paper elucidates the mechanism regulating the subcellular localization of UBE3A and demonstrates that abrogation of UBE3A nuclear localization leads to electrophysiological and behavioral impairments in mice and to Angelman syndrome in humans.
Brazil has a long history in the development of ethanol for use as a liquid fuel for vehicles. They have developed one of most efficient and economical systems for producing ethanol in the world. Brazil provides an example that many other countries would like to emulate. Using ethanol as a vehicle fuel has significant potential air quality impacts. This paper will review the available air quality and vehicle emissions data in Brazil, specifically focusing on vehicle related pollutants that may be impacted by the use of large quantities of ethanol in the fuel. The atmospheric concentrations of acetaldehyde (CH3CHO) and ethanol in Brazil are much higher than those in other areas of the world, while the concentrations of the single ring aromatic compounds and small carboxylic acids are more typical of observations elsewhere. Acetaldehyde and ethanol increase in vehicle emissions and nitrogen oxides (NOx) may increase when ethanol fuels are used. Both CH3CHO and NOx are very important contributors to photochemical air pollution and ozone (O3) formation. There are very significant O3 air quality problems in Brazil, most studied in the larger cities of São Paulo and Rio de Janeiro. These are issues that must be evaluated for other areas of the world that are considering the use of high ethanol content vehicle fuels.
We investigated the effects of PEG–borate ester on the ionic conductivity and transport number of lithium ions in polymer electrolytes with Li-salt, such as LiN(CF3SO2)2, LiClO4 or LiCF3SO3. The ionic conductivity of the polymer electrolyte with LiN(CF3SO2)2 was found to be higher than those of the electrolytes with LiClO4 or LiCF3SO3. This result is mainly concerned with mobility of ions, which is indicated by the comparison of glass transition temperatures of the polymer electrolytes. On the other hand, the transport numbers of lithium ions in the polymer electrolytes with LiClO4 or LiCF3SO3 were higher than those of the electrolyte with LiN(CF3SO3)2. Furthermore, the conductivities of lithium ions calculated by multiplying the ionic conductivity measured by ac impedance with transport number of lithium ions were also found to be higher than that of the electrolytes with LiN(CF3SO2). These results indicate that the PEG–borate ester acts as Lewis acid and interacts with CF3SO3 − or ClO4 − more effectively compared with N(CF3SO2)2 −, leading to improved dissociation of Li-salts and transport number of lithium ions.
This review covers methods to measure key aspects of nanoscale structure in organic photovoltaic devices based on polymer-fullerene bulk heterojunctions. The importance of nanoscale structure to the power conversion efficiency and stability of these devices has been recognized, but robust correlations have yet to emerge despite a significant community-wide research investment. Our perspective is that more uniform selection, execution, and interpretation of nanoscale structure measurements will accelerate this endeavor. We will discuss organic bulk heterojunction structural measurements of contemporary interest and importance including vertical stratification, molecular orientation and order, and nanoscale morphology. Specific recommendations are made regarding the technical implementation of some popular techniques, with an eye toward the elimination of artifacts, ambiguous data, and misinterpretation. When possible, topics are highlighted where there is a community consensus on the results of nanoscale structure measurements and how they may relate to organic photovoltaic device performance.
The polymerization of lithium 2-acrylamido-2-methyl-1-propane sulphonic acid with N,N′-dimethylacrylamide has yielded polyelectrolyte gels which have the favourable property of being single ion conductors. The use of single ion conductors ensures that the transport number of lithium is close to unity. The mobility of the lithium ion is still quite low in these systems, resulting in low ionic conductivity. To increase ionic conductivity more charge carriers can be added however competing effects arise between increasing the number of charge carriers and decreasing the mobility of these charge carriers. In this paper the monomer ratio of the copolymer polyelectrolyte is varied to investigate the effect increasing the number of charge carriers has on the ionic conductivity and lithium ion and solvent diffusivity using pfg-NMR. Ion dissociators such as TiO2 nano-particles and a zwitterionic compound based on 1-butylimidazolium-3-(N-butanesulfonate) have been added in an attempt to further increase the ionic conductivity of the system. It was found that the system with the highest ionic conductivity had the lowest solvent mobility in the presence of zwitterion. Without zwitterion the mobility of the solvent appears to determine the maximum ionic conductivity achievable.
Recently, we have shown silver vanadium phosphorous oxide (Ag2VO2PO4, SVPO) to be a promising cathode material for lithium based batteries. Whereas the first reported preparation of SVPO employed an elevated pressure, hydrothermal approach, we report herein a novel ambient pressure synthesis method to prepare SVPO, where our chimie douce preparation is readily scalable and provides material with a smaller, more consistent particle size and higher surface area relative to SVPO prepared via the hydrothermal method. Lithium electrochemical cells utilizing SVPO cathodes made by our new process show improved power capability under constant current and pulse conditions over cells containing cathode from SVPO prepared via the hydrothermal method.
Objectives An abbreviated gestational period may interrupt intrauterine brain development and constitutes a serious risk factor. Many preterm children show some form of attention deficits in later life. However, there is ambiguity about the nature and extent of these attention deficits in the literature. Moreover, the majority of studies investigated attention functions in preterm children on a symptom based level or using neuropsychological tasks. In contrast, neurophysiological studies have been comparatively scarce which will be addressed in the current study. Methods We investigated attention functioning in 27 low risk preterm children and 20 term children of 5–6 years of age by using EEG recording in an attention driven task (oddball task). Results Compared with term children, preterm children showed no attention deficits on a symptom level, but failed to show an increased oddball P3. Conclusion Current results suggest subclinical attentional changes in preterm children on the electrophysiological level in contrast to normal performance in attentional behavioral tests. Significance Our results emphasize to have a closer look at preterm children early in preschool age even though clinically relevant symptoms seem to be absent.
The lower-than-average cognitive performance of individuals with bilateral cerebral palsy found in previous studies does not always refer to an abnormal performance or clinically significant impairment. We aimed to establish the percentage of persons with bilateral cerebral palsy who present neuropsychologic impairment, and its relationship to perinatal data and motor signs. Forty children, adolescents, and adults (age range, 6-38 years; 15 females and 25 males) with bilateral cerebral palsy were neuropsychologically assessed. Vocabulary was impaired in 85% of participants, language comprehension in 13-48%, visuoperceptual abilities in 60%, visuospatial abilities in 90%, short-term memory in 21-58%, declarative memory in 47-67%, and praxis comprehension in 20%, with executive deficits in 58-74%. Perinatal data (intrauterine growth and birth weight) contributed to explaining memory impairment. Among cerebral palsy subtypes (spastic, mixed, and dyskinetic), forms of impairment differed only in short-term verbal memory. No persons with dyskinetic cerebral palsy experienced impairment in immediate memory or working visual memory. We conclude that visuospatial deficit is the most frequent impairment in people with bilateral cerebral palsy. Moreover, short-term memory impairment seems sensitive to perinatal complications, and differs among bilateral cerebral palsy subtypes.
High temperature sodium batteries with inorganic electrolytes are attracting increasing attention due to their high thermal stability, reliability, long-cycle life and safety. Despite the intensive investigation of Na-NiCl2 batteries during last decades, designing a stable conducting network in the cathode is still challenging but desirable. In this work, a new cathode structure composed of Ni nanowires with an effective electron conducting network is proposed for planar sodium–nickel chloride batteries. During the first stage of charge, Ni nanowires reacted with Cl ion to form NiCl2 on the surface and the excessive Ni nanowires inside can serve as conducting framework to facilitate the fast electron transport. As expected, the metal nanowires show a high specific capacity of 130 mA h g−1 (∼14 mAh cm−2) at 0.05 C after 100 cycles. Meanwhile, the batteries show stable cycling performance at 0.05 C with a high cut-off energy density of 360 W h kg−1, much higher than the traditional tubular sodium-nickel chloride batteries (∼100 Wh kg−1). Scanning electron microscope (SEM) images of the cathode after long cycling reveal the ultra-slow growth of Ni particles, confirming the excellent stability of the prepared nanowires cathode.
The behavior of lithium ions in a comb-like polymer electrolyte with a nitrile group has been characterized by differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), ac impedance, Fourier transform infrared (FTIR) spectroscopy, and 7 Li solid-state NMR measurements. The comb-like copolymer is synthesized by poly(ethylene glycol-methyl ether methacrylate) (PEGMEM) and acrylonitrile (AN). FTIR spectra reveal the interactions of Li+ ions with both the ether oxygen of the PEGMEM and the nitrogen atom of the AN segments. 7 Li solid-state NMR spectra demonstrate the interactions of Li+ ions with both the ether oxygen of the PEGMEM and the nitrogen atom of the AN segments. Moreover, 7 Li solid-state NMR shows that the lithium ions are preferentially coordinated to the PEGMEM segment. The T g increases for the copolymers doped with LiClO4. These results indicate the interactions of Li+ with both PEGMEM and AN segments form transient cross-links. The dependence of the maximum conductivity on the doping lithium ion concentration was determined. The AN unit in the copolymer improves the dissociation of the lithium salt, and the mechanical strength.