batterydata/paper-abstracts huggingface dataset:
The impact of oxygen evolution and bubble formation on the performance of an all-vanadium redox flow battery is investigated using a two-dimensional, non-isothermal model. The model is based on mass, charge, energy and momentum conservation, together with a kinetic model for the redox and gas-evolving reactions. The multi-phase mixture model is used to describe the transport of oxygen in the form of gas bubbles. Numerical simulations are compared to experimental data, demonstrating good agreement. Parametric studies are performed to investigate the effects of changes in the operating temperature, electrolyte flow rate and bubble diameter on the extent of oxygen evolution. Increasing the electrolyte flow rate is found to reduce the volume of the oxygen gas evolved in the positive electrode. A larger bubble diameter is demonstrated to increase the buoyancy force exerted on the bubbles, leading to a faster slip velocity and a lower gas volume fraction. Substantial changes are observed over the range of reported bubble diameters. Increasing the operating temperature was found to increase the gas volume as a result of the enhanced rate of O2 evolution. The charge efficiency of the cell drops markedly as a consequence.
The current study reports on the development and validation of the Academic Diligence Task (ADT), designed to assess the tendency to expend effort on academic tasks which are tedious in the moment but valued in the long-term. In this novel online task, students allocate their time between solving simple math problems (framed as beneficial for problem solving skills) and, alternatively, playing Tetris or watching entertaining videos. Using a large sample of high school seniors (N = 921), the ADT demonstrated convergent validity with self-report ratings of Big Five conscientiousness and its facets, self-control and grit, as well as discriminant validity from theoretically unrelated constructs, such as Big Five extraversion, openness, and emotional stability, test anxiety, life satisfaction, and positive and negative affect. The ADT also demonstrated incremental predictive validity for objectively measured GPA, standardized math and reading achievement test scores, high school graduation, and college enrollment, over and beyond demographics and intelligence. Collectively, findings suggest the feasibility of online behavioral measures to assess noncognitive individual differences that predict academic outcomes.
Abstract Terrorism has risen in prominence over the last few decades, especially after the 9/11 World Trade Center (WTC) attacks. It is an important topic of medicolegal concern. Besides traditional terrorist explosions, now new modes of terrorism have appeared such as narco- and underwater terrorism. This chapter aims to describe the major terrorist challenges that the forensic expert faces today and also outlines the major points of forensic investigations.
Safety remains a major issue for the graphite anode used in lithium-ion batteries. The thermal stability of lithiated graphite was studied by atomic-scale characterization and cell tests. The results revealed that the thermal decomposition of the solid–electrolyte interface is the most easily triggered chemical reaction in lithium-ion cells and plays a critical role in determining the battery safety. It was also shown that natural graphite containing a small amount of 3R graphite had much better thermal stability than mesocarbon microbeads that had no detectable 3R graphite.
Zn2SiO4:Mn2+ phosphor films were successfully prepared by a novel combustion chemical vapor deposition (CCVD) method. In the CCVD process, a flammable solution, containing precursor materials, is atomized and sprayed through a specially designed nozzle and ignited to form a combustion flame. This enables crystallized films to be directly deposited onto a substrate in open-atmosphere with no post deposition heat treatment. SEM images indicated that the film deposited at 1200°C consisted of densely packed particles with a fine grain size of several 100nm. Strong Photoluminescence (PL) and cathodoluminescence (CL) intensities were observed with Zn2SiO4:Mn2+ samples deposited at a substrate temperature of 1200°C exhibiting the best crystallinity and highest luminescence. The optimum doping level for films deposited using CCVD was found to be ∼4mol% Mn2+ of starting concentration, with a maximum CL luminescence equivalent to 53% of the luminescence measured from a commercial powder phosphor. A relatively fast CL decay with life time about 0.6–0.7ms was also observed from these films.
Hollingsworth & Vose (H&V) is planning to install a wet-laid microglass manufacturing line in its Suzhou, China mill to serve filtration and battery separator markets.
There is a persistent need for high resolution photographic images of the sea floor and associated biota for marine habitat classification and fisheries stock assessment. This paper presents a novel low cost Lagrangian imaging platform that offers high quality images with reduced operational demands in comparison to existing methodologies such as diver surveys, drop cameras, ship towed systems and dedicated remote or autonomous underwater vehicles. The platform consists of a recently developed bottom following Lagrangian float fit with down looking stereo cameras and strobe lighting. The float can use active ballasting to perform constant altitude photographic drift surveys in coastal waters over varying bathymetry. Images from the float can be used to create large photomosaics, stereographic bathymetry estimates and image-derived current measurements. Test data are presented to demonstrate the operation of the Lagrangian float and summarize the data products.
The European study entitled: “Market Potential Analysis for Introduction of Hydrogen Energy Technology in Stand-Alone Power Systems (H-SAPS)” aimed to establish a broad understanding of the market potential for H-SAPS and provide a basis for promoting in wide scale new technological applications. The scope of the study was limited to small and medium installations, up to a few hundred kW power rating and based on RE as the primary energy source. The potential for hydrogen technology in SAPS was investigated through an assessment of the technical potential for hydrogen, the market analysis and the evaluation of external factors. The results are mostly directed towards action by governments and the research community but also industry involvement is identified. The results include targeted market research, establishment of individual cost targets, regulatory changes to facilitate alternative grid solutions, information and capacity building, focused technology research and bridging the technology gaps.
In the Turkish community at large, especially among educators, there have almost always been many arguments about the validity of the Turkish University Entrance Test (TUET). The common belief is that the TUET is not a valid measure for academic achievement in undergraduate programs (AAUP). The current empirical research study attempted to investigate whether the TUET is a valid measure for AAUP or not. A Turkish university students sample was selected and the issue was investigated by using two main variables. Namely, the TUET scores and the undergraduate program GPAs. The data were statistically analyzed and interpreted. This research study is important in that it can help provide a solid answer to the ongoing arguments against the TUET and, the most important of all, its findings can be useful for some decision-making processes concerning the construction of the TUET and the student selection and placement for undergraduate programs.
Publisher Summary This chapter reflects the threat of existence and potential usage of bioweapons elaborating upon the history, programs, epidemiology, tools, bioinformatics and genetics of microbial forensics. Science plays an important role in criminal investigation, and microbial forensic science continues to assist in solving crimes by characterizing physical evidence found at a crime scene. Advances in technology will develop better treatments and therapies for many microbial diseases that affect humans, animals, and plants. However, technology can be misused to challenge the national and international security by using pathogens or toxins as weapons. In forensics, the crime scene is recognized and secured to preserve the quality of the evidence. Vigilance is necessary to detect the use of bioweapons. The chapter also stresses on educational efforts as a key to disease surveillance and appropriate public response to a disease outbreak, whether it is intentional or natural. By developing a robust microbial forensics field supported by the Bio forensic Analysis Center (BFAC), a developed knowledge base, integration of government; academic; and private sector institutions, and the standing working group— Scientific Working Group on Microbial Genetics and Forensics (SWGMGF), the global society can overcome the challenge of bioterrorism.
Orthorhombic LiMnO2 was synthesized via the sol–gel process using citric acid as a chelating agent. The effect of varying the molar acid to metal ions ratio (R) on the structural and electrochemical properties of the synthesized compound was studied. Samples with high R (R=1,2) contain large amount of MnO impurity phase, which is electrochemically inactive and thus is detrimental to the electrochemical activity of the electrode. Therefore, the acid to metal ions ratio “R” should not be high. Samples with low R (R=0.5) exhibited a high initial capacity, above 190mAh/g when cycled at a current density of 0.4mA/cm2 at room temperature. The ac impedance results show that the initial capacity was improved (compared with ss-o-LiMnO2) due to the smaller particle size and good homogeneity, which improves the Li+ diffusion in the cathode.
Intermittent, fluctuational, and unpredictable features of renewable energy require grid-level energy storage (GES). Among various types of GES, aqueous electrochemical storage is undoubtedly the most promising method due to its high round-trip efficiency, long cycle life, low cost and high safety. As the most encouraging candidate for aqueous electrochemical storage, aqueous rocking-chair batteries have been heavily investigated. Recently, intercalation-type aqueous batteries beyond the limits of Li+ and Na+ have caught researchers’ attention due to potentially higher capacity and better cyclability, and the number of publications in this nascent field since 2015 has dramatically increased. Therefore, it is highly demanded to summarize what have been learned in this field. In this first comprehensive review paper, we summarize these novel intercalation-type electrode materials and provide perspectives of opportunities and challenges for future research.
Fundamental understanding of how processing affects composite battery electrode structure and performance is still lacking, especially for industry-relevant electrodes with low fractions of inactive material. This work combines rheology, electronic conductivity measurements, and battery rate capability tests to prove that short-range electronic contacts are more important to cathode rate capability than either ion transport or long-range electronic conductivity. LiNi0.33Mn0.33Co0.33O2, carbon black, and polyvinylidene difluoride in 1-methyl-2-pyrrolidinone represent a typical commercial electrode with <5.5 wt% inactive material. Dry-mixing carbon black with active material decreases the relative fraction of bulk (free) carbon, as shown by small angle oscillatory shear and microscopy. More free carbon leads to a stronger gel network (more long-range particle contacts) and higher electronic conductivity of the dried films. Improvements in battery rate capability at constant electrode porosity do not correlate to electronic conductivity, but rather show an optimum fraction of free carbon. Simple comparison of rate capability in electrodes with increased total carbon loading (3 wt%) shows improvement for all fractions of free carbon. These results clearly indicate that ion transport cannot be limiting and highlight the critical importance of short-range electronic contacts for controlling battery performance.
Core–shell structured Si/C nanocomposites with different nitrogen contents are prepared by in situ polymerization of aniline in the suspension of silicon nanoparticles followed by carbonization of Si/polyaniline (PANI) nanocomposites at different temperatures. The nitrogen contents of Si/C nanocomposites decrease gradually with increasing carbonization temperatures. The effect of nitrogen contents on the electrochemical performance of Si/C nanocomposites as anode materials for lithium ion batteries is investigated. It is found that the Si/C nanocomposites with 4.75wt.% nitrogen exhibit the high specific capacity of 795mAhg−1 after 50 cycles at a current density of 100mAg−1 and excellent cycling stability. The appropriate nitrogen in Si/C nanocomposites plays a beneficial role in the improvement of electrochemical performance. The nitrogen in Si/C nanocomposites increases the reversible capacity, which may be due to the formation of vacancies and dangling bonds around the nitrogen sites.
An economical and scalable synthesis route of LiFePO4 nanoplate precursors is successfully prepared in pure water phase under atmosphere without employing environmentally toxic surfactants or high temperature and high pressure compared with traditional hydrothermal or solvothermal methods, which also involves recycling the filtrate to regenerate LiFePO4 nanoplate precursors and collecting by-product Na2SO4. The LiFePO4 precursors present a plate-like morphology with mean thickness and length of 50–100 and 100–300nm, respectively. After carbon coating, the LiFePO4/C nanoparticles with particle size around 200nm can be observed which exhibit a high discharge capacity of 160mAhg−1 at 0.2C and 107mAhg−1 at 20C. A high capacity retention closed to 91% can be reached after 500 cycles even at a high current rate of 20C with coulombic efficiency of 99.5%. This work suggests a simple, economic and environmentally benign method in preparation of LiFePO4/C cathode material for power batteries that would be feasible for large scale industrial production.
In this work we investigate the electrochemical behavior of a new type of carbon–lithium sulfide composite electrode. Results based on cyclic voltammetry, charge (lithium removal)-discharge (lithium acceptance) demonstrate that this electrode has a good performance in terms of reversibility, cycle life and coulombic efficiency. XRD analysis performed in situ in a lithium cell shows that lithium sulfide can be converted into sulfur during charge and re-converted back into sulfide during the following discharge process. We also show that this electrochemical process can be efficiently carried out in polymer electrolyte lithium cells and thus, that the Li2S–C composite can be successfully used as cathode for the development of novel types of rechargeable lithium-ion sulfur batteries where the reactive and unsafe lithium metal anode is replaced by a reliable, high capacity tin–carbon composite and the unstable organic electrolyte solution is replaced by a composite gel polymer membrane that is safe, highly conductive and able to control dendrite growth across the cell. This new Sn–C/Li2S polymer battery operates with a capacity of 600mAhg−1 and with an average voltage of 2V, this leading to a value of energy density amounting to 1200Whkg−1.
Here is the evaluating result on the applicability of the multi-walled carbon nanotube (MWCNT) and α-iron (III) oxide (α-Fe2O3) nanocomposite as a cathode material in dye-sensitized solar cells (DSCs). The morphology and the structure of the MWCNT/α-Fe2O3 nanocomposite have characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray elemental mapping analysis. Moreover, the electrochemical performance of the nanocomposite has studied toward the activity of Iˉ/I3 ˉ redox couple which represents high current density, low peak-to-peak separation, low charge-transfer resistance, and almost 100% stable response signal. Furthermore, the computational modeling employing the molecular mechanics (MM) and the restricted-Hartree Fock/semiempirical parameterization (RHF/PM6) methods reveals that the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and the HOMO-LUMO energy gap of the modeled nanocomposite are as −6.88, −3.62, and 3.26 eV, respectively. These properties match with the electronic-level domino of the DSC structure. Finally, the DSC device has fabricated using N719-sensitized TiO2 photoanode and MWCNT/α-Fe2O3 counter electrode, presenting the open-circuit potential, the short-circuit current density, and the power-conversion efficiency of 0.7 V, 20.37 mA cm−2, and 6.0%, respectively. This study successfully approves the potential of the nanocomposite as a cathode material in iodine-based dye-sensitized solar cells.
Thin films of controlled thickness of Co/Al layered double hydroxide with different Co and Al percentages have been electrosynthesized by the cathodic reduction of a 0.03M Co and Al nitrate solution. The electrochemical behaviour of the films deposited on Pt or ITO electrodes has been deeply studied in 0.1M NaOH solution. Our findings demonstrate that as soon as a potential is applied in the anodic direction, the films undergo an irreversible change of phase.
Ionic liquids (ILs) containing zwitterions were studied as electrolytes for lithium-ion batteries. The effect of a pyrrolidinium zwitterion with a long ether side chain on the thermal and electrochemical properties of an IL and the charge/discharge properties of Li/LiCoO2, Li/LiNi1/3Mn1/3Co1/3O2 (NMC), and graphite/Li cells with IL/zwitterion electrolytes was investigated. The melting temperature of the IL-based electrolyte composed of N-methyl-N-methoxymethylpyrrolidinium bis(fluorosulfonyl)amide ([Pyr1,1O1][FSA]) and lithium bis(fluorosulfonyl)amide (LiFSA) with 3-(1-(2-(2-methoxyethoxy)ethyl)pyrrolidin-1-ium-1-yl)propane-1-sulfonate (OE2pyps) as the zwitterionic additive was about −18°C. The electrochemical window of [Pyr1,1O1][FSA]/LiFSA/OE2pyps was over 5V vs. Li/Li+. Li|electrolyte|LiCoO2 cells containing the [Pyr1,1O1][FSA]/LiFSA/OE2pyps electrolyte system exhibited high capacity values in the cut-off voltage range of 3.0–4.3V, even after 50 cycles. Moreover, increases of interfacial resistance between the electrolyte and cathode during cycling were suppressed. Li|electrolyte|NMC cells containing this electrolyte system also exhibited high capacities in a wide cut-off voltage range of 3.0–4.6V, even after 50 cycles. In the cyclic voltammograms of cells employing a graphite electrode, the intercalation/deintercalation of lithium ions was observed between 0 and + 0.4V vs. Li/Li+. Further, graphite|electrolyte|Li cells containing [Pyr1,1O1][FSA]/LiFSA/OE2pyps exhibited stable charge/discharge cycle behavior over 5 cycles.
Hybrid, solid polymer electrolyte films consisting of poly (vinyl chloride) (PVC), poly (acrylonitrile) (PAN) and, propylene carbonate (PC) with different concentrations of LiClO4 are prepared by means of a using solvent-casting technique. The structure and complex formation are studied by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The temperature dependence of the ionic conductivities of the polymer films is explained in terms of a free volume model. The conductivities of PVC–PAN–LiClO4–PC complexes are determined at different salt concentrations. The highest ionic conductivity (8.35×10−5 Scm−1) is obtained for 8wt.% LiClO4 in the polymer complex at 304K. The thermal stability of the electrolyte is examined by thermogravimetric/differential thermal analysis (TG/DTA).
Powder of raw pitch coke was activated with alkali hydroxides at 500–900°C to prepare carbon electrode of high capacitance for electric double layer capacitor (EDLC). KOH provided very high surface area of 2320m2/g at 800°C, while NaOH did moderate surface area of 1000m2/g at 650–750°C. High surface area provided by KOH led to a high capacitance per weight of 39F/g. However, its capacitance per volume was as low as 16F/ml. Although the coke of moderate surface area activated with NaOH showed a similar capacitance per weight, its capacity per volume was as high as 28F/ml because of its high density. Adequate porosity must be selectively introduced by NaOH activation to the coke to obtain moderate surface area. Much smaller expansion of layers in the present needle type coke activated by NaOH than that by KOH is indicative for the higher density of the former activated coke.
Garnets are promising solid electrolytes for developing solid state Li batteries, owing to their features of relatively high conductivity and stability against lithium metal. However, they show shortcoming of Li penetration through garnets during Li plating and stripping, which limits their practice application. Herein, we present a strategy to solve such problem by coating SnO2 films on the surfaces of the Li6 · 4La3Zr1 · 4Ta0 · 6O12 pellets. Through conversion reaction of SnO2 with Li at 200 °C, the nanocomposite layers consisting of crosslinked LixSn and Li2O are formed between the Li and the Li6 · 4La3Zr1 · 4Ta0 · 6O12 electrolytes. This leads to transition from lithiophobicity to lithiophilicity, thus greatly reducing interfacial resistance from 1100 Ω cm2 to 25 Ω cm2. Furthermore, taking advantage of suppressing volume change of LixSn alloy which is about 260%, the intermediate layers maintain integrity under the current densities of 0.2 mA cm−2 for 650 h cycles. In addition, the critical current density of Li/SnO2-Li6.4La3Zr1 · 4Ta0 · 6O12-SnO2/Li can be as high as 1.15 mA cm−2. As a proof-of-concept, this effective interface modification based on conversion reaction method contributes to a useful way of solving the Li/garnet interface problem and promoting the solid state Li batteries development.
Thin polymeric membranes such as Celgard are commonly used as separators in Li-ion batteries to ensure high volumetric energy density. Independently, for silicon-based electrodes fluoroethylene carbonate (FEC) is often added to the electrolyte to improve the cycling stability of the cell. Here we demonstrate that, counterintuitively, this separator–electrolyte combination negatively affects the performance of graphite–Si electrodes in half-cells. In a statistical evaluation of the cycling behavior of C–Si electrode cells with various separators and either with or without FEC addition, we show that by improving the solid electrolyte interphase on the silicon particles, FEC addition leads to inhomogeneous current distribution in the electrodes, therefore favoring lithium dendrite growth and leading to irreversible failure with Celgard. In contrast, self-recovery is observed with simple glass-fiber separators. Without FEC, neither dendrites nor failure are observed, but cells with Celgard suffer from poorer electrochemical performance, due to clogging by the thick polymeric layer formed using standard electrolytes, than cells with thicker and hydrophilic separators.
The Li2S–Cu composite electrode materials were prepared by mechanical milling and applied to all-solid-state lithium cells using the Li2S–P2S5 glass–ceramic electrolyte. The addition of Cu and the mechanical activation improved the electrochemical performance of Li2S in all-solid-state cells. The In/Li2S–Cu cells were charged and then discharged at room temperature, suggesting that Li2S was utilized as a lithium source. The cells exhibited high discharge capacity of about 490mAhg−1 at the 1st cycle. The SEM and EDX analyses suggested that the amorphous Li x CuS domain was partially formed by milling, and the domain played an important role in the improvement of capacity. The electrochemical reaction mechanism of the Li2S–Cu composites was discussed on the basis of the mechanism of the S–Cu composite electrode.