batterydata/paper-abstracts huggingface dataset:
In this work, different water-soluble binder systems are investigated in view on their influence on adhesion, porosity and electrochemical performance of Li1Ni0.33Mn0.33Co0.33O2 composite cathodes, with the aim to establish a low viscosity binder system for ultra-thick electrodes. Different mixtures of sodium carboxymethylcellulose, polyacrylic acid and polyethylene oxide are used as binder in a fixed ratio of 3 wt.-% regarding the solid components. A ternary composition of carboxymethylcellulose/polyacrylic acid/polyethylene oxide is identified as superior binder candidate regarding electrode paste viscosity and electrode adhesion. Starting from 60 wt.-%, the solid content of the electrode paste is increased to 65 wt.-% using the new binder system. Applying solid contents, homogenous and crack free electrodes with an active mass loading of up to 60 mg cm−2 are produced. Cycled against graphite anodes, these cathodes show specific capacities of 85 mAh∙g−1 (5 mAh∙cm−2) at 0.2C (1.8 mA cm−2). In a further step, the capacity is successfully increased to 120 mAh∙g−1 (6 mAh∙cm−2) at 0.2C (1.5 mA cm−2) using carbon micro fibers as additive. Beyond that, the electrode paste based on carbon micro fibers shows superior performance in comparison to a polyvinylidene difluoride-based reference system.
Public concern about oil and gas (O&G) operations in residential areas is substantial. Noise from construction and drilling related to O&G operations may be greater than other phases of O&G operations; yet the impacts of audible and low-frequency noise during these operations are not extensively explored nor the effects on health well understood. This study documents the noise levels at a multi-well O&G well pad during construction and drilling in a residential area in Colorado. A-weighted (dBA) and C-weighted (dBC) noise measurements were collected at four locations during development over a 3-month period. The maximum 1-min equivalent continuous sound levels over a 1-month period were 60.2 dBA and 80.0 dBC. Overall, 41.1% of daytime and 23.6% of nighttime dBA 1-min equivalent continuous noise measurements were found to exceed 50 dBA, and 97.5% of daytime and 98.3% of nighttime measurements were found to exceed 60 dBC. Noise levels exceeding 50 dBA or 60 dBC may cause annoyance and be detrimental to health; thus, these noise levels have the potential to impact health and noise levels and associated health effects warrant further investigation.
A substantial part of electric vehicles (EVs) powertrain is the battery cell. The cells are usually connected in series, and failure of a single cell can deactivate an entire module in the battery pack. Hence, understanding the cell behaviour helps to predict and improve the battery performance and leads to design a cost effective thermal management system for the battery pack. A first principle thermo electrochemical model is applied to study the cell behaviour. The model is in good agreement with the experimental results and can predict the heat generation and the temperature distribution across the cell for different operating conditions. The operating temperature effect on the cell performance is studied and the operating temperature for the best performance is verified. In addition, EV cells are examined in a realistic driving cycle from the Artemis class. The study findings lead to the proposal of some crucial recommendation to design cost effective thermal management systems for the battery pack.
The redox mechanism of micro-sized FeS2 particles in a rechargeable lithium battery is studied by galvanostatic cycling and ac-impedance analysis. It is shown that FeS2 is irreversibly reduced on the first discharge, turning Li/FeS2 cell into a combination of Li/FeS and Li/S chemistries, as suggested by two distinct discharge plateaus at ∼1.5 and 2.0V, respectively. The first discharge consists of an irreversible conversion of FeS2 to Li2FeS2 intermediate and its subsequent reduction to metallic Fe and Li2S. The first discharge suffers an initial voltage delay, suggesting that the discharge progresses in a thermodynamic non-equilibrium condition. The initial voltage delay can be attributed to the large grain boundary resistance (GBR) of pristine FeS2 particles, which impedes the nucleation of a new solid Li2FeS2 phase causing high polarization. Ac-impedance spectra of the FeS2 cathode are composed of a semicircle and a straight sloping line, representative of an electrode reaction resistance (Rer) and a Li+ adsorption impedance, respectively. The Rer is found to decrease progressively during the first discharge and reaches a plateau when the cell is charged above 2.5V vs. Li/Li+, being consistent with the model that FeS2 is irreversibly reduced during the first discharge and that the Li2S/Li2Sn redox couple is formed in recharge. It is indicated that Li/FeS2 batteries face the same problems as Li/S batteries, such as the dissolution of lithium polysulfide, the formation of a redox shuttle, and the loss of sulfur active material.
3,6-Poly(phenanthrenequinone) (PPQ) is synthesized and tested as a conductive binder. The PPQ binder, formulated with nano-sized Si powder without conductive carbon, is n-doped by accepting electrons and Li+ ions to become a mixed conductor in the first charging period. The resulting n-doped PPQ binder remains conductive thereafter within the working potential of Si (0.0–0.5 V vs. Li/Li+). Within the composite electrode, the PPQ binder is uniformly dispersed to effectively convey electrons from the current collector to the Si particles. Namely, the PPQ binder by itself plays the roles of conductive carbon and a polymer binder that are loaded in the conventional composite electrodes. Due to the highly conductive nature, the loading of the PPQ binder can be minimized down to 10 wt%, which is close to that used for practical electrode formulation, with reasonable rate and cycle performances of the nano-Si electrode.
New test equipment and characterization methods for aging investigations on lithium-ion cells for automotive applications are presented in this work. Electrochemical impedance spectroscopy (EIS) is a well-established method for cell characterization and analyzing electrochemical processes. In order to integrate this method into long-term aging studies with real driving currents, new test equipment is mandatory. The presented test equipment meets the demands for high current, wide bandwidth and precise measurement. This allows the cells to be cycled and characterized without interruption for changing the test device. The characterization procedures must be of short duration and have a minimum charge-throughput for negligible influence on the aging effect. This work presents new methods in the time and the frequency domain for obtaining the impedance spectrum which allow a flexible trade-off between measurement performance, time consumption and charge-throughput. In addition to sinusoidal waveforms, rectangular, Gaussian and sin(x)/x pulses are applied for EIS. The performance of the different methods is discussed. Finally, the time domain analysis is applied with real driving currents which provides impedance spectra for state of charge estimation considering aging effects in the car.
A battery fuel gauge (BFG) helps to extend battery life by tracking the state of charge (SOC) and many other diagnostic features. In this paper, we present an approach to validate the SOC and time-to-shutdown (TTS) estimates of a BFG. Hardware-in-the-loop (HIL) testing under realistic usage scenarios provides a means for BFG algorithm evaluation and provides insights into practical implementation and testing of BFG algorithms in battery management systems. We report the details of a HIL system that was designed to validate the SOC and TTS estimation capability of BFG algorithms; different current load profiles were synthesized to replicate typical battery usage in portable electronic applications; the HIL system is automated with the help of programmable current profiles and is designed to operate at various controlled temperatures; three performance validation metrics are formulated for an objective assessment of SOC and TTS tracking algorithms. The HIL setup and the performance validation metrics are used to evaluate a BFG developed by the authors using three different batteries at temperatures ranging from - 20 ° C to 40 ° C .
The lymphatic system has become the subject of great interest in recent years because of its important role in normal and pathological processes. Progress in understanding the origins and early development of this system, however, has been hampered by difficulties in observing lymphatic cells in vivo and in performing defined genetic and experimental manipulation of the lymphatic system in currently available model organisms. Here, we show that the optically clear developing zebrafish provides a useful model for imaging and studying lymphatic development, with a lymphatic system that shares many of the morphological, molecular and functional characteristics of the lymphatic vessels found in other vertebrates. Using two-photon time-lapse imaging of transgenic zebrafish, we trace the migration and lineage of individual cells incorporating into the lymphatic endothelium. Our results show lymphatic endothelial cells of the thoracic duct arise from primitive veins through a novel and unexpected pathway.
Mixing a small amount of Al(OH)3 powder with a LiCoO2 cathode material is demonstrated to improve markedly the cycle performance and thermal stability of commercial grade LiCoO2/graphite lithium-ion batteries. Al(OH)3-mixed LiCoO2/graphite prismatic cells exhibit excellent capacity retention as high as 95% after 400 cycles with negligible polarization build-up. Moreover, the thermal stability of the cells is greatly improved by Al(OH)3 mixing, which is confirmed by higher residual and recovery capacity ratios after storage at 90°C compared with a pristine cell. The beneficial effects of Al(OH)3 are found to be related mainly to an improvement of the cathode side, which is ascribed to reduced unwanted side-reactions with the electrolyte.
Zinc metal batteries (ZMBs) provide a promising alternative to lithium metal batteries but share the formidable challenges in reversibility. The authors discuss the key performance metrics of ZMBs and propose a protocol to assess the true reversibility of zinc metal anodes.
Under the one-child policy and with the economic development, there has been an annual rise in both anxious emotions and behavioral problems among students with learning difficulties. In order to evaluate the relationship between anxious emotions and behavioral problems, this study adopted a quantitative approach to randomly select 6000 elementary school students in Jiangsu Province of China, then screened 714 anxious children with learning disabilities. The conclusions of this research were as follows: for children with learning difficulties, their anxious emotions and behavioral problems were above average, notably their social phobia and learning problems; behavioral problems of children with learning difficulties varied due to demographic variables, and there was a significant interaction effect of rearing styles and family atmospheres on children’s behavioral problems; separation anxiety, social phobia, generalized anxiety disorder, family atmosphere (harmony), rearing style (democracy), parental expectation (self-sufficiency) and somatization/panic disorder of children with learning difficulties could predict their behavioral problems. Based on the results, this study proposed a few suggestions for educators and future researchers.
The introduction of nitrogen heteroatoms into carbon materials is a facile and efficient strategy to regulate their reactivities and facilitate their potential applications in energy conversion and storage. However, most of nitrogen heteroatoms are doped into the bulk phase of carbon without site selectivity, which significantly reduces the contacts of feedstocks with the active dopants in a conductive scaffold. Herein we proposed the chemical vapor deposition of a nitrogen-doped graphene skin on the 3D porous graphene framework and donated the carbon/carbon composite as surface N-doped grapheme (SNG). In contrast with routine N-doped graphene framework (NGF) with bulk distribution of N heteroatoms, the SNG renders a high surface N content of 1.81 at%, enhanced electrical conductivity of 31 S cm−1, a large surface area of 1531 m2 g−1, a low defect density with a low I D/I G ratio of 1.55 calculated from Raman spectrum, and a high oxidation peak of 532.7 °C in oxygen atmosphere. The selective distribution of N heteroatoms on the surface of SNG affords the effective exposure of active sites at the interfaces of the electrode/electrolyte, so that more N heteroatoms are able to contact with oxygen feedstocks in oxygen reduction reaction or serve as polysulfide anchoring sites to retard the shuttle of polysulfides in a lithium–sulfur battery. This work opens a fresh viewpoint on the manipulation of active site distribution in a conductive scaffolds for multi-electron redox reaction based energy conversion and storage.
The development of a free-standing electrode with high rate capability requires the realization of facile electrolyte percolation, fast charge transfer at the electrode-electrolyte interface as well as the intimate electrical wiring to the current collector. Employing a sulfonated high internal phase emulsion polymer (polyHIPE) as the carbon precursor, we developed a free-standing composite of carbon foam encapsulated SnO2 nanocrystallites, which simultaneously satisfies the aforementioned requirements. When directly evaluated in the pouch cell without using the binder, carbon additive or metallic current collector, the best performing composite exhibits a good rate performance up to 8 A g−1 and very stable cyclability for 250 cycles. This cycling performance was attributed to the synergistic coupling of hierarchical macro/mesoporous carbon foam and SnO2 nanocrystals with optimized size range. Postmortem characterizations unveiled the significant influence of subtle size variation of oxides on the electrochemical performance.
Large, sub-alpine, stratified lakes are directly within the scope of the European Water Framework Directive (WFD) and need adapted monitoring systems. Moreover, anthropogenic eutrophication was frequently the main cause of their water quality degradation in the 20th century. This paper is primarily aimed at demonstrating how in situ sensor-equipped buoys could be the base of monitoring designs to support the WFD objectives. The core of this paper, mainly methodological, focuses on single-depth, high frequency (4 per hour) fluorescence measurements. It shows that the internal wave pattern provides additional information to the single-depth time series to assess phytoplankton dynamics in a stratified water column displaying strong, vertical biomass heterogeneity. The paper deals with the following three aspects: (1) definition of an indicator to determine whether or not the sensor actually detects the metalimnetic fluorescence peak, (2) vertical representation of chlorophyll distribution from single-depth series; (3) time evolution of the fluorescence peak (maximum value, depth and associated temperature, peak width).
The influence of oxygen on the electrochemical response of magnesium–scandium (Mg–Sc) thin film electrodes has been investigated. It was found that the impact of oxygen dissolved in the electrolyte is two-fold. Firstly, it gives rise to a mixed-potential under open-circuit conditions that is much more positive than the true equilibrium potential of the hydride material, thus yielding incorrect thermodynamic data. Secondly, it causes self-oxidation of the hydrogenated thin films, making calculations regarding hydrogen storage capacities (mAh/g) not straightforward. A novel oxygen-scrubbing device was developed to de-oxygenate the argon used as purging gas during the electrochemical measurements. This self-regenerative system is based on the high reactivity of the methylviologen single radical towards oxygen. A comparison between various electrochemical responses of identical Mg–Sc thin film electrodes, measured with and without the presence of oxygen, showed distinct deviations in equilibrium potential and hydrogen storage capacity.
The abundant and low-cost potassium resources promote potassium-ion batteries (KIBs) as promising energy storage devices, thus accelerating the investigation of ideal electrode materials to accommodate the large-size K-ions. Here, a nano-rose-like MoS2 confined in reduced graphene oxide (MoS2@rGO) is evaluated as anode material to boost K-ion storage. The MoS2@rGO hybrid not only features large specific surface area for excellent electron conductivity and facile K-ions diffusion, but also provides a robust three-dimension (3D) network with stable interfacial connection through strong chemical bonds (Mo-C and Mo-O-C) between MoS2 and rGO, which can alleviate the mechanical stress to guarantee the structure stability during cycling. It is also confirmed that both intercalation and conversion reaction mechanisms, based on four-electrons-transfer, play an important role in K-ions insertion/extraction. Hence, the initial capacity of 438.5 mAh·g−1 with excellent cycling stability (capacity retention of 95.0% after 200 cycles) at 100 mA g−1 and the remarkable rate capability (196.8 mAh·g−1 at 2 A g−1) among many reported anodes are achieved for MoS2@rGO. No obvious fading at 500 mA g−1 can be observed over ultra-long lifespan of 1000 cycles. Finally, the K-ion full cells are assembled with K2Fe[Fe(CN)6] cathode to demonstrate the practical application.
We propose a stochastic mixed integer optimization model to optimally size a solar power system and its battery storage for residential and nonresidential customers of electric power. The objective function of the model is to minimize the total cost associated with solar power system investments and the grid provided electric power over a planning horizon. We consider the uncertainty associated with solar radiation, load, and electricity price in the form of probabilistic scenarios. The model can be used with different grid pricing programs and under no net metering or net metering programs, respectively. A numerical example and its parametric analyses are used to demonstrate the efficacy of the model and develop some insights into optimal sizing of a battery storage enabled solar system. The analyses show the size of the solar system is influenced by the labor cost and the load size whereas the size of the battery storage is sensitive to the load size and the battery cost. Moreover, we find the optimal number of solar panels/batteries is larger under the net metering program than under no net metering program.
Ethiopia is one of five countries that account for half of the world’s 2.6 million newborn deaths. A quarter of neonatal deaths in Ethiopia are caused by birth asphyxia. Understanding different dimensions of the quality of care for newborns with breathing difficulties can lead to improving service provision environments and practice. We describe facility readiness to treat newborns with breathing difficulties, the extent to which newborn resuscitation is provided, and by modeling the survival of newborns with difficulties breathing, we identify key factors that suggest how mortality from asphyxia can be reduced.
Of all the companies that saw the early years of the last Century, only about a quarter are recognisable today - and some of those only by a brand name. Inco is one the select few that have won through 100 turbulent years to celebrate its centenary. Chairman and Chief Executive Scott Hand says the company plans to be in business for a long time to come…
Ni3[Fe(CN)6]2 nano-cubic precursors were prepared by chemical coprecipitation at room temperature with nickel acetate and potassium ferricyanide as raw materials. The corresponding NiFe2O4-NiO@C composites with excellent crystallization were prepared by two-stage oxidation at low temperature. The microstructure and electrochemical behavior of the materials showed that the Prussian blue analog was transformed into metal oxide while the carbon coating was maintained in the two-stage oxidation at low temperature. The existence of the carbon coating reduces the charge transfer impedance to 31.5 Ω. At the current density of 500 mA/g, the reversible capacity of 632.7 mAh/g is maintained after 500 cycles. At the same time, carbon cladding can also enhance the role of pseudocapacitance in the material. At the scanning rate of 0.1 mV/s, the pseudocapacitance account for 54.4% of the total discharge capacity, which is significantly higher than that of uncoated materials.
There have been many advances in vitreoretinal surgery since Machemer introduced the concept of pars plana vitrectomy, in 1971. Of particular interest are the changes in the vitrectomy cutters, their fluidics interaction, the wide-angle viewing systems and the evolution of endoillumination through the past decade and notably in the last few years. The indications of 27-gauge surgery have expanded, including more complex cases. Cut rates of up to 16,000 cuts per minute are already available. New probe designs and pump technology have allowed duty cycle performances of near 100% and improved flow control. The smaller vitrectomy diameter can be positioned between narrow spaces, allowing membrane dissection and serving as a multifunctional instrument. Enhanced endoillumination safety can be achieved by changing the light source, adding light filters, increasing the working distance and understanding the potential interactions between light and vital dyes commonly used to stain the retina. Wide-angle viewing systems (contact, non-contact or a combination of both) provide a panoramic view of the retina. Non-contact systems are assistant-independent, while contact systems may be associated with better image resolution. This review will cover some current aspects on vitrectomy procedures, mainly assessing vitrectomy cutters, as well as the importance of endoillumination and the use of wide-angle viewing systems.
Field-portable detectors have been frequently used in routine monitoring and hazard assessment studies. However, there have been few thorough attempts to evaluate their potential as an alternative to the traditional procedure of collecting samples and analysing them in the laboratory. Thus, in this study the two approaches were compared in terms of their utility for monitoring 137Cs activity in the Nyänget catchment in northern Sweden. The objectives were: (i) to determine the 137Cs activity in soils associated with three types of vegetation, (ii) to map the geographical distribution of 137Cs using the portable NaI detector connected to a GPS system (GDM-40), (iii) to identify 137Cs anomalies in the catchment, and (iv) to compare the measurements obtained with the NaI detector and traditional sampling followed by laboratory analysis. Our results demonstrate that the GDM-40 has very good potential for making 137Cs inventories and for detecting 137Cs anomalies within large areas. The GDM-40 measurements identified differences between different hydrological areas that were not determined with the soil sampling method. The GDM-40 method is much faster than a traditional soil sampling method. However, soil sampling cannot be totally excluded because it is needed to calibrate the GDM-40. The agreement between the 137Cs activity values obtained by the two approaches was 20% which is good in the field where so many factors vary.