batterydata/paper-abstracts huggingface dataset:
Lithium vanadium fluorophosphate (LiVPO4F) composite with three-dimensional conductive networks architecture is synthesized with synergistic modification of pyrolytic carbon (C), multi-walled carbon nanotubes (MWCNTs) and graphene sheets (rGO). The differences between LiVPO4F@C, LiVPO4F@C/MWCNTs, LiVPO4F@C/rGO and LiVPO4F@C/MWCNTs/rGO composites are compared through a variety of characterization means. By means of SEM and TEM analysis, it can be seen that pyrolyzed C, MWCNTs and rGO are interwoven, which forms a three-dimensional conductive network structure wrapping the LiVPO4F particles. The difference of discharge specific capacity between LiVPO4F@C and LiVPO4F@C/MWCNTs/rGO composites is becoming larger and larger with the increase of charge-discharge rate. Additionally, CV and EIS results indicate that the LiVPO4F@C/MWCNTs/rGO has the smallest polarization value and charge transfer impedance (Rct) as well as the highest diffusion coefficient of lithium ion (DLi+) in all samples. Consequently, LiVPO4F@C/MWCNTs/rGO composite exhibits a high rate capability (97.9 mAh/g cycles at 10 C) and cycling stability (93.74% capacity retention over 800 cycles at 10 C)，showing potential application for high power LIB with high voltage.
A recent ECVAM workshop considered how to reduce falsely predictive positive results when undertaking in vitro genotoxicity testing, and thus to avoid unnecessary follow-up with tests involving animals. As it was anticipated that modified versions of existing assays as well as new assays might contribute to a solution, an expert panel was asked to identify a list of chemicals that could be used in the evaluation of such assays. Three categories of test chemicals were chosen comprising a total of 62 compounds. This paper provides test results for these chemicals using the GreenScreen HC assay. All tests were carried out in triplicate, by multiple operators, with and without S9, using invariant protocols. Group 1 chemicals should be detected as positive in in vitro mammalian cell genotoxicity tests: 18/20 (90%) were reproducibly positive in GreenScreen HC. Group 2 chemicals should give negative results in in vitro genotoxicity tests: 22/23 (96%) were reproducibly negative in GreenScreen HC. Overall concordance for Groups 1 and 2 is 93%. Group 3 chemicals should give negative results in in vitro mammalian cell genotoxicity tests, but have been reported to induce chromosomal aberrations or Tk mutations in mouse lymphoma cells, often at high concentrations or at high levels of cytotoxicity: 13/17 (76%) were reproducibly negative in GreenScreen HC. Of the four positive compounds in Group 3, p-nitrophenol was only positive at the top dose (10mM), 2,4-DCP is an in vivo genotoxin, and two chemicals are antioxidant compounds that may be acting as pro-oxidants in the hyperoxic conditions of cell culture. Overall, these predictive figures are similar to those from other studies with the GreenScreen HC assay and confirm its high specificity, which in turn minimizes the generation of falsely predictive positive results.
Photovoltaic (PV) is a fast growing segment among renewable energy (RE) systems, whose development is owed to depleting fossil fuel and climate-changing environmental pollution. PV power output capacity, however, is still low and the associated costs still high, so efforts continue to develop PV converter and its controller, aiming for higher power-extracting efficiency and cost effectiveness. Different algorithms have been proposed for Maximum Power Point Tracking (MPPT). Since the choice of right converter for different application has an important influence in the optimum performance of the photovoltaic system, this paper reviews the state-of-the-art in research works on non-isolated DC–DC buck, boost, buck–boost, Cúk and SEPIC converters and their characteristics, to find a solution best suiting an application with Maximum Power Point Tracking. Review shows that there is a limitation in the system's performance according to the type of converter used. In can be concluded that the best selection of DC–DC converter which is really suitable and applicable in the PV system is the buck–boost DC–DC converter since it is capable of achieving optimal operation regardless of the load value with negotiable performance efficiency and price issue.
The current array of commercially produced cathode materials for advanced lithium-ion batteries is poorly suited to today’s energy supply demands. A current example of this problem is the unsatisfactory range of commercially available electric vehicles or even of mobile electronic devices. The bottleneck of capacity is the availability of cathode materials like LiCoO2 that also has associated safety risks. Lithium conducting phosphates with the olivine structure LiMPO4 (M = Fe, Mn, Co, Ni) with a theoretical capacity of approximately 170 mAh g−1 might provide recourse. LiNiPO4 has received increasing interest in recent years, mainly because of its similar structure to LiFePO4, which was shown to have beneficial electrochemical properties after a few years of intensive research. An optimized nickel phosphate would in theory possess an even higher energy density, because of its redox potential of about 5.1 V vs. Li/Li+. Nevertheless advances in ionic and electronic conductivity as well as electrochemical reversibility of LiNiPO4 are rare and the reasons are not fully understood. This review presents an overview of recent progress in the fabrication of LiNiPO4 powders and the general synthesis approaches to circumvent the drawbacks of LiNiPO4. The impacts of these fabrication methods on the purity, structure, and electrochemical performance of LiNiPO4 powders are discussed. Particular attention is paid to electrochemical activation of nickel in the olivine structure and recent trials to apply LiNiPO4 in aqueous and nonaqueous lithium-ion batteries are reviewed. On the basis of this rigorous study a complete picture of the state of the art of LiNiPO4 as a possible cathode material and its perspectives is given.
The application of lead-acid batteries for automobile applications has to meet stringent specification guidelines. Design engineers are more concerned to meet the high rate discharge (HRD) performance of a battery, particularly for automobile applications. The required HRD is to be tested to the full satisfaction of the ultimate user. This paper gives a review on lead-acid batteries manufactured in India with special focus on their HRD performance. Basically, there is a cut-off voltage (which is 7.20V for a 12V battery system) down to which the battery shall be able satisfactorily to deliver current to the starting mechanism of a vehicle at the low critical temperature of −18°C. For determination of HRD performance under simulated conditions a high rate discharge tester is used to draw a constant discharge current from the battery, kept and conditioned in a cold chamber. It uses a built-in data acquisition system for logging of current and voltage values at an interval of 5s.
The vanadium(IV) electrolyte solutions with various vanadium concentrations are studied by variable temperature 1H and 17O nuclear magnetic resonance (NMR) spectroscopy. The structure and kinetics of vanadium(IV) species in the electrolyte solutions are explored with respect to vanadium concentration and temperature. It was found that the vanadium(IV) species exist as hydrated vanadyl ion, i.e. [VO(H2O)5]2+ forming an octahedral coordination with vanadyl oxygen in the axial position and the remaining positions occupied by water molecules. This hydrated vanadyl ion structure is stable in vanadium concentrations up to 3M and in the temperature range of 240–340K. The sulfate anions in the electrolyte solutions are found to be weekly bound to this hydrated vanadyl ion and occupies its second-coordination sphere. The possible effects of these sulfate anions in proton and water exchange between vanadyl ion and solvent molecules are discussed based on 1H and 17O NMR results.
In the last issue we covered the ‘Zero Energy Home’ in the US; this time we turn the focus of attention to wider matters, but still related to the installation of PV in communities around the world. As a glance through the news in any issue of PVB will show, the diversity of installations is quite remarkable. Not only for domestic and commercial use, but also along our transport networks — and now even to pump oil. PV is clearly moving ‘closer to home’. But the fragmented nature of what is essentially a bespoke business of installing PV is counter-productive. To fulfil its potential, maybe the industry needs more standardization.
The influence of cell temperature on the current density distribution and accompanying inhomogeneities in state of charge (SOC) during cycling is analyzed in this work. To allow for a detailed insight in the electrochemical behavior of the cell, commercially available 26650 cells were modified to allow for measuring local potentials at four different, nearly equidistant positions along the electrodes. As a follow-up to our previous work investigating local potentials within a cell, we apply this method for studying SOC deviations and their sensitivity to cell temperature. The local potential distribution was studied during constant current discharge operations for various current rates and discharge pulses in order to evoke local inhomogeneities for temperatures ranging from 10 °C to 40 °C. Differences in local potentials were considered for estimating local SOC variations within the electrodes. It could be observed that even low currents such as 0.1C can lead to significant inhomogeneities, whereas a higher cell temperature generally results in more pronounced inhomogeneities. A rapid SOC equilibration can be observed if the variation in the SOC distribution corresponds to a considerable potential difference defined by the open circuit voltage of either the positive or negative electrode. With increasing temperature, accelerated equalization effects can be observed.
Metal-hydride based hydrogen storage materials have recently been designed for rechargeable batteries where protons serve as charge carriers. However, the metal-hydride materials generally suffer from poor cycling stability during electrochemical hydrogen storage process. Herein, we report, for the first time, a new AB4-type single-phase La0.78Mg0.22Ni3.67Al0.10 metal-hydride superlattice compound with excellent electrochemical hydrogen storage properties. This metal-hydride compound is able to deliver a high discharge capacity of 393 mAh g−1, according to its hydrogen gas absorbability (1.50 wt%), and exhibit a superior rate capability of 180 mAh g−1 even at 1.8 A g−1. In addition, the compound retains its crystalline structure when subjects to electrochemical cycling and shows strong anti-oxidation ability in alkaline electrolyte, indicative of excellent cyclability. Our results demonstrate that the AB4-type superlattice structure metal-hydride can be a promising electrode material for hydrogen storage, and provide a new avenue for the applications of metal-hydride batteries.
Electrochemical impedance measurements were performed on graphitic anodes during their galvanostatic cycling in LiBOB/PC electrolyte, and the variation of each impedance component was studied as the function of the lithiation state. It was found that the charge-transfer component was closely related to the formation of the solid electrolyte interface (SEI), characterized by a sharp drop in the corresponding resistances between OCV and 0.60V, while the semi-circle in the medium frequency range might arise from contact impedance components within the electrode, because it varies reversibly during the lithiation/delithiation cycle. The irreversible reduction process at 1.70V, which is characteristic of LiBOB salt, was confirmed to originate from the reductive decomposition of oxalate ester impurities, and this process is believed to be unrelated to the protective SEI formed by LiBOB electrolytes on graphitic anode. When compared with the corresponding LiPF6-based electrolytes, it was concluded that the alkyl carbonates are not appropriate solvents for LiBOB salt, both in terms of the power and low temperature performances in lithium ion cells.
SnO2 has attracted growing attention as a promising anode material for next generation of Lithium ion batteries because of its high theoretical capacity (1494 mAh g−1) and low working potential. However, the severe volume change during cycling remains one of the great challenges for its practical application. To overcome the obstacle, we propose to utilize the SnO2 quantum dots loaded on the sulfur-doped reduced graphene oxides by one-pot synthesis. The SnO2 quantum dots are uniformly dispersed on the sulfur-doped reduced graphene oxides and retain their tiny sizes during the electrochemical reaction, thus alleviate the volume expansion. Meanwhile, the sulfur-doped reduced graphene oxides introduces many defects and can benefit charge transfer and lithium ion diffusion in the electrode. With the synergetic effect between SnO2 quantum dots and sulfur-doped reduced graphene oxides, the composite anode material can deliver a specific capacity of 897 mA h g−1 at 100 mA g−1 and maintain 88% of original capacity after over 500 cycles at 500 mA g−1, featuring large lithium ion storage capacity and high stability.
Here we report on a novel enzyme-free glucose sensor based on nanoporous palladium–cadmium (PdCd) networks. A facile hydrothermal method was employed in the synthesis of different PdCd nanomaterials with controllable compositions. The morphology, composition and crystalline structure of the fabricated nanoporous PdCd electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction spectroscopy (XRD), respectively. The glucose sensor was prepared via the deposition of the synthesized PdCd nanomaterials on a glassy carbon (GC) electrode. The effect of the composition of the nanoporous PdCd on the performance of the electrode was investigated by cyclic voltammetry (CV) and amperometry. Our electrochemical studies showed that the PdCd/GC electrode responds to the direct oxidation of glucose with high electrocatalytic activity. The electrode exhibited optimal performance under a potential of −0.4V at which interference from ascorbic acid (AA), uric acid (UA) and 3-acetamidophenol (AP) is effectively minimized. The sensitivity of the sensor for continuous glucose monitoring was 146.21μAmM−1 cm−2 with linearity up to 10mM and a detection limit of 0.05mM (S/N=3).
The electrodeposition of lithium metal from room temperature ionic liquid (RTIL) electrolytes consisting of N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr13[FSI]) with LiFSI, LiTFSI, LiBF4, LiPF6 or LiAsF6 salts onto Pt and Li electrodes was undertaken to identify mechanistic details. Cyclic voltammetry at both Pt and Li electrodes is complicated by the chemical reaction between fresh/electrodeposited Li metal and electrolyte to form a solid-electrolyte interphase (SEI). As such, all electrolyte systems depict quasi-reversible cycling, owing to the concomitant chemical breakdown of the electrolyte and deposition of a passivation product onto the electrode surface. The rate at which the SEI forms can be observed through cyclic voltammetric scan rate studies. Chronoamperometry data supports the cyclic voltammetry studies and indicates that an instantaneous nucleation and growth type mechanism is taking place at all potentials as determined through modelling the current-time transients utilising the Hills-Scharifker theory. We show herein that these RTIL based electrolytes can be cycled effectively in an order of stability of salt inclusion as follows: LiBF4 >LiFSI>LiAsF6 >LiTFSI>LiPF6.
Lithium-sulfur (Li-S) batteries have the theoretical energy density up to 2600 Wh/kg, but its commercialization is limited by poor cyclic performance, low coulombic efficiency and high material cost. In this work, the polar cross-linked polystyrene/sulfur (PCP/S) composite with a sulfur content of 58 wt% is firstly synthesized as the cathodes for Li-S batteries, in which these polar cross-linked polystyrene agents effectively adsorb polysulfides with a large specific surface area and various functional groups, resulting in an enhancement of the cycle performance and coulombic efficiency for Li-S batteries. The first specific discharge capacity of the PCP/S cathode is 1309.7 mAh g−1 at 0.2 C, which can remain as high as 659.7 mAh g−1 after 400 cycles with a low capacity decay of 0.124% per cycle.
Transport microenvironments represent hotspots of personal exposure to airborne toxics, particularly of ultrafine particles. Thus, a large exposure may be experienced during daily commuting trips. Amongst these microenvironments, bus stops are critical because of the commuters' close proximity to fresh fumes rich in particles emitted by passing, idling and accelerating buses and motor vehicles, in general. Standing at a bus stop may represent a period of disproportionately high exposure and it is, therefore, essential to know the number, chemical composition and physical characteristics of such particles for a proper public health assessment and design of mobility strategies. On this account, a set of portable and battery operated sensors were used to evaluate a number of properties of the traffic particles to which thousands of citizens are daily exposed at bus stops of Singapore. In terms of fine particles, the exposure concentration was on average 1.5–3 times higher than the mean concentration at ambient level reported by the local authorities. On average 60% of those particles corresponded to black carbon. An important presence of particle-bound polycyclic aromatics was observed. The particle number concentration and active surface area were effective metrics to quantify ultrafine particles, as expected both showed strong correlations. The number of particles at bus stops was on average 3.5 times higher than at ambient level. The most alarming issue was probably the size of the particles. Assuming spherical particles, a median of 27 nm was estimated based on the active surface area and particle number data. Particles of this size form the nucleation mode, which is related to harmful health effects.
As the computer disappears in the environments surrounding our activities, the objects therein become augmented with sensors, actuators, processors, memories, wireless communication modules and they can receive, store, process and transmit information. In addition to objects, spaces also undergo a change towards becoming smart and eventually Ambient Intelligence (AmI) spaces. In order to model the way everyday activities are carried out within an AmI environment, we introduce the notion of “activity sphere”. In this paper, we are interested in the ontology-based representation of activity spheres from two different perspectives (as creators and as observers), as well as the modeling and control of the dynamic nature of activity spheres.
Fleets of commercial vehicles for delivery services in urban areas constitute road transportation means which are required to run relatively short distances and to respect anti-pollution laws commonly imposed by many municipalities. For this kind of commercial applications, high efficiency and eco-friendly electric propulsion systems offer an interesting alternative to thermal engines. This paper is focused on the analysis of such solution, by presenting experimental results obtained with a ZEBRA battery based propulsion system, designed to power a specific urban unit within the category of electric commercial vehicles. A novel contribution is added to the relevant literature concerning battery based electric powertrains for road vehicles. The main novelty consists in a wide range of experimental results and performance analysis carried out with reference to the real behavior of both the whole propulsion system and each main component, when powering the commercial vehicle, on the urban part of the NEDC (New European Driving Cycle) standard driving cycle, at different slopes. The experimental results, expressed through electrical and mechanical parameters, are initially evaluated by means of a quasi-static numerical model of the electric powertrain and then experimentally verified with the support of a 1:1 scale laboratory dynamic test bench. The procedure followed and presented in this paper definitely demonstrates the good design and performance, obtained for the evaluated propulsion system, in satisfying the real energy and power requirements, specific of an urban use for delivery commercial vehicles, in terms of daily autonomy and slopes. The collections of experimental results, analyzed in the paper, represent in addition a useful set of data for simulation in order to build, verify and improve models in their outputs.
This work reports an electrochemical study of antimony-carbon composites. The study has been carried out by testing in lithium cells two samples of Sb–C electrodes, differing by the relative composition and by the dimensions of the antimony particles. The results show that the particle size has crucial role in influencing the cycling response of the Li–Sb cells in terms of the extent and the maintenance of the capacity delivery.
This paper describes a strategy for fabricating porous nanotube arrays and how the Ni(OH)2 electrode composed of porous nanotubes exhibits better pseudocapacitive behavior compared to Ni(OH)2-coated ZnO nanorod and Ni(OH)2 film electrodes. Ni(OH)2 electrode with porous nanotubes is fabricated by hydrolysis and cathodic deposition using electrodeposited ZnO nanorods as a template. The Ni(OH)2 nanoflakes grow on the stainless steel substrate and around the ZnO nanorods during cathodic deposition. After the removal of the ZnO template, hollow nanotubes with porous walls of interconnected nanoflakes are formed. The porous nanotube structure facilitates easy electrolyte transport to the reaction sites and leads to a further increase in the specific capacitance of electrode. The specific capacitance of porous Ni(OH)2 nanotube electrode reaches as high as 1581 F g−1, which is much higher than that of Ni(OH)2-coated ZnO nanorod (874 F g−1) and compact Ni(OH)2 film (569 F g−1) electrodes at a discharge current density of 1 A g−1.
In recent years, Wireless Sensor Networks (WSNs) have emerged as a new powerful technology used in many applications such as military operations, surveillance system, Intelligent Transport Systems (ITS) etc. These networks consist of many Sensor Nodes (SNs), which are not only used for monitoring but also capturing the required data from the environment. Most of the research proposals on WSNs have been developed keeping in view of minimization of energy during the process of extracting the essential data from the environment where SNs are deployed. The primary reason for this is the fact that the SNs are operated on battery which discharges quickly after each operation. It has been found in literature that clustering is the most common technique used for energy aware routing in WSNs. The most popular protocol for clustering in WSNs is Low Energy Adaptive Clustering Hierarchy (LEACH) which is based on adaptive clustering technique. This paper provides the taxonomy of various clustering and routing techniques in WSNs based upon metrics such as power management, energy management, network lifetime, optimal cluster head selection, multihop data transmission etc. A comprehensive discussion is provided in the text highlighting the relative advantages and disadvantages of many of the prominent proposals in this category which helps the designers to select a particular proposal based upon its merits over the others.