batterydata/paper-abstracts huggingface dataset:
Conventional cooling approaches that target either a singular tab or outer surface of common format cylindrical lithium-ion battery cells suffer from a high cell thermal resistance. Under an aggressive duty cycle, this resistance can result in the formation of large in-cell temperature gradients and high hot spot temperatures, which are known to accelerate ageing and further reduce performance. In this paper, a novel approach to internal thermal management of cylindrical battery cells to lower the thermal resistance for heat transport through the inside of the cell is investigated. The effectiveness of the proposed method is analysed for two common cylindrical formats when subject to highly aggressive electrical loading conditions representative of a high performance electric vehicle (EV) and hybrid electric vehicle (HEV). A mathematical model that captures the dominant thermal properties of the cylindrical cell is created and validated using experimental data. Results from the extensive simulation study indicate that the internal cooling strategy can reduce the cell thermal resistance by up to 67.8 ± 1.4% relative to single tab cooling, and can emulate the performance of a more complex pack-level double tab cooling approach whilst targeting cooling at a single tab.
Visual modelling assumes a graphic form of model description and visual representation of research results. The main element of modelling system representation is a block diagram. Owing to appearance of this line of investigation («object-oriented modelling») a software was produced (for example, Simulink in MatLab). The examples of ordinary differential equations solving schemes for initial stage discharge of lead-acid battery positive electrode visual modelling are presented. The comparative analysis of two algorithms (a shooting method and algorithm similar to back propagation algorithm used in the neural networks theory) also is carried out.
Well-to-Wheel (WtW) CO2 emissions of different powertrain topologies employed to power a medium duty truck are analyzed in this paper. The analysis covers topologies of the parallel and the series plug-in hybrid electric vehicles (PHEVs), which are driven according to different strategies of depletion of the electric storage devices (ESs). These results are benchmarked against results of conventional internal combustion engine vehicles (ICEVs). The Tank-to-Wheel (TtW) data are obtained by a forward facing vehicle simulation model, whereas Well-to-Tank (WtT) analysis covers CO2 intensity of the Diesel fuel and four different realistic CO2 intensities of electric energy production. To ensure comprehensiveness of the study vehicles were also operated according to two drive cycles that feature significantly different velocity profiles. In addition, influences of different control strategies of powertrain components were also analyzed. This broad portfolio of scenarios reveals insightful WtW CO2 emissions guidelines for introducing plug-in hybrid electric trucks to different regions. The results indicate that the propulsion electrification in medium duty trucks has, in comparison to passenger cars, a smaller potential for reduction of Well-to-Wheel CO2 emissions because of the higher efficiencies of the internal combustion engine in such trucks. Results of this study were also used to identify the threshold value of the CO2 intensity of electric energy production that favors the operational switch from Charge Depleting (CD) to Charge Sustaining (CS) mode. Additionally, it was shown that for longer recharge intervals, operation in the blended mode with less intensive depletion rate of the ES can feature lower WtW CO2 emissions of the PHEVs.
The reactivity of conducting polymers can be exploited to generate new sensors of their working conditions. Here, we verified that the reactive (redox) nature of a chemically generated polypyrrole (PPy) on a polyurethane (PU) microfibrous mat senses the surrounding (physical and chemical) conditions. The (PU/PPy) microfibrous mat was obtained by in situ chemical polymerization of pyrrole from aqueous medium using tetra fluoromethane sulfonate as dopant and a polyurethane microfibrous mat, produced by electrospinning of a PU solution, as template. SEM images showed the homogenous growth of nanostructured PPy on each fiber of the PU microfibrous mat. The cyclic voltammogram (CV) revealed an oxidation peak at 0.22V and a reduction peak at −0.08V vs Ag/AgCl, indicating that the electrochemical activity of the material is imparted by PPy component. Sensing abilities with regard to the surrounding conditions were monitored through chronopotentiometric (CP) responses between two defined oxidation states. The consumed electrical energy during the electrochemical reactions was a linear function of the applied currents or of the working temperature (the reaction material is a current sensor and a temperature sensor) and a semi-logarithmic dependence of the electrolyte concentration (concentration sensor). These sensing abilities are explained on the basis of recently developed theories on the reactivity of conducting polymers.
The development of efficient non-noble metal electrocatalysts for the oxygen reduction reaction (ORR) is still highly desirable before non-noble metal catalysts can replace platinum catalysts. Herein, we have synthesized a new type of ORR catalyst, Co3(PO4)2C-N/rGOA, containing N-coordinated cobalt phosphate, through the thermal treatment of a phosphonate-based metal–organic framework (MOF). Co3(PO4)2C-N/rGOA exhibits not only a comparable onset potential and half-wave potential but also superior stability to the commercial Pt/C catalyst for the ORR in alkaline solutions (0.1 and 1.0 M KOH). A combination of structural characterization (e.g., XPS, HRTEM, XANES, and EXAFS) and electrochemical analysis shows that the high ORR activity of the Co3(PO4)2C-N/rGOA catalyst should be attributed to the co-existence of N-doped graphitic carbon and the cobalt phosphate with Co–N species that boost the activity of the cobalt phosphate. These findings open an avenue for exploring the use of phosphonate-based MOFs for energy conversion and storage applications.
Lithium carbonate is commonly found on the surfaces of lithiated cathode active materials that have been exposed to air. Long-term exposure of LiNi0.8Co0.15Al0.05O2 electrodes produced a dense Li2CO3 coating, approximately 10nm in thickness that severely reduced both the accessible capacity and the rate at which the electrodes could be cycled. Ex situ X-ray diffraction patterns of cycled electrodes revealed a bimodal distribution of active material in different states of charge. Particle isolation is proposed to contribute to both capacity and power losses, and possible mechanisms related to the formation of Li2CO3 are discussed.
This chapter discusses individual adhesive types in detail. The adhesives have been arranged in alphabetical order, without regard to classification. Certain general categories are also listed, such as alloys, aromatic polymer, conductive, elastomeric adhesives, anaerobic, film and tape adhesives, hot-melt adhesives, inorganic glues, microencapsulated adhesives, rubber-based adhesives, solvent-based systems, thermoplastic resin adhesives, thermosetting-resin adhesives, and water-based adhesives. The chapter begins with a brief overview of the modern history of adhesive compounds. Practically all adhesives were derived from plant or animal sources before the twentieth century. The main classes included glue from animal bones, fish glue, and vegetable adhesives. Progress in organic chemistry and an increased demand for adhesives led to the development of syntheticcompounds, beginning with phenol-formaldehydes and casein adhesives. Developments in polymerization and adhesive chemistry proceededin a near parallel fashion.
We describe spatial and temporal patterns of seven chemical elements commonly observed in fine particulate matter (PM) and thought to be linked to roadway emissions that were measured at residential locations in New York City (NYC). These elements, that is, Si, Al, Ti, Fe, Ba, Br, and black carbon (BC), were found to have significant spatial and temporal variability at our 10 residential PM2.5 sampling locations. We also describe pilot study data of near-roadway samples of both PM10−2.5 and PM2.5 chemical elements of roadway emissions. PM2.5 element concentrations collected on the George Washington Bridge (GWB) connecting NYC and New Jersey were higher that similar elemental concentration measured at residential locations. Coarse-particle elements (within PM10−2.5) on the GWB were 10–100 times higher in concentration than their PM2.5 counterparts. Roadway elements were well correlated with one another in both the PM2.5 and PM10−2.5 fractions, suggesting common sources. The same elements in the PM2.5 collected at residential locations were less correlated, suggesting either different sources or different processing mechanisms for each element. Despite the fact that these elements are only a fraction of total PM2.5 or PM10−2.5 mass, the results have important implications for near-roadway exposures where elements with known causal links to health effects are shown to be at elevated concentrations in both the PM2.5 and PM10−2.5 size ranges.
As we saw in the previous chapter, the birth of analog was dominated by just eight companies in the USA, UK and Japan, whose history in the field all spanned 20 years or less. But there were many other participants in the growth of analog, some offering innovative design features in very short production runs, others bringing well-established technology to a wider market or a new level of affordability, and these companies spanned the whole world – from the UK, USA and Japan to Germany, France, the Netherlands and Italy, Russia and even China.
Nowadays SiO/C anode has been considered as the higher energy density energy storage candidate. However, the drastic material expansion and irreversible capacity fading in the prolonged cycling process limits its further application in many dynamic fields. In this article, 4, 5‑difluoro‑1, 3‑dioxolan‑2‑one (DFEC) is reported as a film forming additive to improve the electrochemical performance of LiNi0.8Co0.15Al0.05O2/SiO@C full cells. The cells with 2% DFEC keeps the best capacity retention of 88.7% after 500cycles comparing to 83.9% of blank group. The main reason is that the deterioration of the SiO/C particle has been greatly alleviated. As for cyclic voltammograms and scanning electron microscopy measurement, DFEC is reduced over 1.5V prior to the blank electrolyte in the first cycle, which indicates DFEC can participate in the formation of solid electrolyte interphase film on the anode surface. X-ray photoelectron spectroscopy results demonstrate that there are fewer side reaction products on the DFEC-contained anode.
Using lithium acetate dihydrate and tetra-n-butyl titanate as the raw materials, spinel Li4Ti5O12 was successfully synthesized by a modified rheological phase method. Thermogravimetric analysis and differential scanning calorimetry (TG–DSC) of the thermal decomposition process of the precursor and X-ray diffraction (XRD) data indicate the crystallization of lithium titanates has occurred at 580°C, and main phase Li4Ti5O12 has obtained at 600°C. Laser granulometer and scanning electron microscope (SEM) have been employed to estimate the particle size distribution, morphology and microstructure of the products. It reveals the prepared Li4Ti5O12 powder had a small particle size (about 140nm) and narrow size distribution (d 0.1 =0.07, d 0.5 =0.139, d 0.9 =2.813μm). Galvanostatic charge and discharge tests were carried out to characterize the electrochemical performances of Li4Ti5O12. The result indicates that the Li4Ti5O12 electrode material obtained from the precursor that had been experienced heat treatment at 110°C exhibited discharge capacities of 161.6, 156.5 and 112.3mAhg−1 after 50 cycles at current rates 1, 2.5 and 10C, respectively, demonstrating excellent high rate performance, due to the pure and well crystallized Li4Ti5O12 with ultrafine particles and narrow size distribution.
The thermal stability of electrochemically lithiated disordered carbon with a poly(vinylidene difluoride) binder and 1moldm−3 LiPF6 dissolved in a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) was investigated by differential scanning calorimetry (DSC) using a hermetically sealed pan. The disordered carbon used was prepared by pyrolyzing peanut shells with porogen at temperatures above 500°C. The disordered carbon gave much larger charge and discharge capacities than graphite when a weight ratio of porogen to peanut shells was set at 5. In DSC curves, several exothermic peaks were observed at temperatures ranging from 120 to 310°C. This behavior was similar to that for electrochemically lithiated graphite, except for an exothermic peak at around 250°C. However, the lithiated disordered carbon had a higher heat value, which was evaluated by integrating a DSC curve, compared to lithiated graphite. The heat values increased with an increase in accumulated irreversible capacities. These results suggest that heat generation at elevated temperatures should increase as an amount of irreversibly trapped lithium-ion increases. On the other hand, heat values per reversible capacities for disordered carbon, which showed larger capacities than graphite, were almost comparable to that for graphite. These results indicate that several types of disordered carbon showed larger capacity than graphite, while their thermal stability was lowered accordingly.
Electrodeposition and dissolution of zinc in sulfuric acid were studied as the negative electrode reactions in acidic zinc-based redox flow batteries. The zinc deposition and dissolution is a quasi-reversible reaction with a zinc ion diffusion coefficient of 4.6 × 10−6 cm2 s−1 obtained. The increase of acid concentration facilitates an improvement in the kinetics of zinc electrodeposition–dissolution process. But too high acid concentration would result in a significant decrease in charge efficiency. The performance of the zinc electrode in a three-electrode system with magnetic stirring was also studied as a function of Zn(II) ion concentration, sulfuric acid concentration, current density, and the addition of additives in 1 M H2SO4 medium. The optimum electrolyte composition is suggested at high zinc(II) concentration (1.25 M) and moderate sulfuric acid concentration (1.0–1.5 M) at a current density range of 20–30 mA cm−2. Whether in acid-free solution or in sulfuric acid solution with or without additives, no dendrite formation is observed after zinc electrodeposition for 1 h at 20 mA cm−2. The energy efficiency is improved from 77 % in the absence of additives in 1 M H2SO4 medium to over 80 % upon the addition of indium oxide or SLS–Sb(III) combined additive as hydrogen suppressants.
This study evaluated the mechanical properties and the surface elemental composition of Yasargil Phynox aneurysm clips implanted for 10 years in a patient with cerebral aneurysm. Two Yasargil Phynox aneurysm clips implanted 10 years previously to treat a ruptured vertebral artery aneurysm were retrieved when the regrown and ruptured aneurysm was repaired with a new aneurysm clip. Two new Yasargil aneurysm clips were used as controls. Measurements of closing force, bending strength, and the elemental composition of the clip surface were performed. The closing force of the retrieved clips was similar or greater compared to the force before implantation. The bending test showed that the elastic limit and 0.2% proof load of the retrieved clip were higher than those of the unused clip, whereas the ultimate load of the retrieved clip was similar to that of the unused clip. The elemental concentration of Cr oxide on the surface of the retrieved clips was almost the same as that on the unused clips. The present study demonstrated that Yasargil Phynox aneurysm clips retain their mechanical properties and surface elemental composition in vivo for a long time, which indicates that Yasargil aneurysm clips will remain reliable in patients for extended periods.
A novel graphene–polyaniline nanocomposite material synthesized using chemical precipitation technique is reported as an electrode for supercapacitors. The graphene (G)–polyaniline (PANI) nanocomposite film was dissolved in N-Methyl-2-pyrrolidone (NMP) and characterized using Raman, FTIR, Scanning Electron Microscopy, Transmission Electron Microscopy, and cyclic voltammetry (CV) techniques. The interesting composite structure could be observed using different ratios of graphene and aniline monomer. The supercapacitor is fabricated using G–PANI in N-Methyl-2-pyrrolidone (NMP) and G–PANI-Nafion films on graphite electrodes. A specific capacitance of 300–500Fg−1 at a current density of 0.1Ag−1 is observed over graphene–PANI nanocomposite materials. The aim of this study is to tailor the properties of the capacitors through the optimization of their components, and packaging towards a qualification for portable systems applications. Based on experimental data shown in this work, conducting polymer nanocomposite capacitor technology could be viable, and could also surpass existing technologies when such a novel approach is used.
The oxygen evolution reaction is of paramount importance in clean energy generation and storage. While the common approach in search of active, durable and cost-effective oxygen evolution catalysts involves the development of novel materials, it is equally important to tune the properties of existing materials so as to improve their catalytic performance. Here, we demonstrate the general efficacy of electrochemical lithium tuning in organic electrolyte on enhancing the oxygen evolution catalytic activity of olivine-type lithium transition metal phosphates, a widely-researched family of cathode materials in lithium ion batteries. By continuously extracting lithium ions out of lithium transition metal phosphates, the materials exhibited significantly enhanced water oxidation catalytic activity. Particularly, the electrochemically delithiated Li(Ni,Fe)PO4 nanoparticles anchored on reduced graphene oxide sheets afforded outstanding performance, generating a current density of 10 mA cm−2 at an overpotential of only 0.27 V for over 24 h without degradation in 0.1 M KOH, outperforming the commercial precious metal Ir catalysts.
We herein report a potential point-of-use platform for multivariate analyses by presenting homemade potentiostat and smartphone. This system combined high-performance detection (linear sweep, cyclic, and square wave voltammetry) with great simplicity, low-cost, portability, autonomy (6h), and cable-free (wireless communication) device. In addition, the smartphone showed ability for processing complex and multivariate data. To the best of our knowledge, this paper is the first reporting about the development of a totally integrated point-of-use system with chemometric data processing on smartphone. This feature is essential for in-situ assays by allowing the real-time accomplishment of the entire analytical measurement at remote places. Such ability further reduces the occurrence of model overfitting by non-expert users. As proof-of-concept, our system was successfully applied to fingerprint Brazilian honey samples according to their botanical and geographic origins. The method relied on the unsupervised technique of principal component analysis (PCA) and the assays were performed by cyclic voltammetry using a single and non-modified working electrode of gold.
The effect of the anode flow field design on the performance of an in-house fabricated micro direct methanol fuel cell (μDMFC) with an active area 1.0cm×1.0cm was investigated experimentally. Single serpentine and parallel flow fields consisting of micro channels were tested. The experimental results indicated that the serpentine flow field exhibited significantly higher cell voltages than did the parallel flow field, particularly at high current densities. The study of the effect of channel depth of the serpentine flow field suggested that there exists an optimal channel depth for the same channel width and the same open ratio when the same methanol flow rate is supplied; either shallower or deeper channels will lead to a reduction in the cell performance. Finally, it was demonstrated that performance of the μDMFC with the reactants fed by an active means was insensitive to the cell orientations, which is different from conventional DMFCs with larger flow channels reported in the literature.
The effect of succinonitrile (SN) additive on cycle life at room temperature is performed with 18650 type cylindrical cell including Li(Ni0.5Co0.2Mn0.3)O2 and graphite. It is clearly investigated that the capacity degrades during cycling at room temperature with adding SN additive. In particular, the capacity of the cell with 1.5 wt % SN dramatically decreases from 60 cycles and by 45% of initial capacity after 100 cycles. Through analyzing cycled cells with different amount of SN additive using XRD and ICP-OES measurement, the amount of irreversible Li increases depending on the amount of SN additive and the number of cycling. The results of SEM and XPS measurement provide that the increased irreversible Li appears as a film-type reactant on the surface of anode electrode and it consists of components related with C-C, CO3, and Li. These analysis results verify that the SN additive affects generation of Li-carbonate species deposition and irreversible Li leads to a degradation of capacity.
Ordered LiNi0.5Mn1.5O4 hollow microspheres have been synthesized by an impregnation method followed by a simple solid-state reaction, and their electrochemical performance is investigated as cathode material for lithium ion batteries. The morphologies of the LiNi0.5Mn1.5O4 products prepared at different temperatures reveal that the formation for the hollow structure is tightly relative to the temperature for the solid-state reaction. Then ordered LiNi0.5Mn1.5O4 hollow microspheres are formed under the solid-state reaction temperature of 800°C along with post-annealing at 700°C, but the sample prepared without post-annealing exists at the form of disordered structure. When the ordered LiNi0.5Mn1.5O4 hollow microspheres were applied as the cathode materials for lithium ion batteries, they exhibited superior rate capability (116 mAh g−1 at 5C, 85 mAh g−1 at 10C for charge and discharge) and good cyclability, which are much better than the disordered sample. The durable high-rate capability was attributed to their single-crystal surface configuration that benefits fast Li insertion/extraction kinetics.
Polyvinylpyrrolidone (PVP)-assisted Bi2WO6 nanoparticles were successfully synthesized by sonochemical method. Three different concentrations of PVP (0.05, 0.1, and 0.2 g) were used, and their effects over the structural, morphological, compositional, and electrochemical analysis were studied. The structural investigation revealed the formation of 100 % pure Bi2WO6 phase. The presence of carbon in the PVP-assisted materials was evidenced from differential scanning calorimetry, Fourier transform infra red (FT-IR) spectroscopy and Raman analysis. There was a reduction in the particle size of Bi2WO6 (30–35 nm) upon using PVP. The highly crystalline nature and the presence of carbon coating over Bi2WO6 were evidenced from the high-resolution transmission electron microscopic image. Besides, the calculated d-spacing of 0.19 nm attributed to (2 0 6) lattice plane of Bi2WO6 nanoparticles. Subsequently, a shift in binding energy toward larger values while using PVP was identified through X-ray photoelectron spectroscopic analysis. The electrochemical analysis showed a subsequent enhancement in specific capacitance of PVP-assisted Bi2WO6 (462 F g−1) compared with pristine Bi2WO6 (304 F g−1) at 3 mA cm−2.