batterydata/paper-abstracts huggingface dataset:
The mesoporous Li3V2(PO4)3@CMK-3 nanocomposite has been firstly synthesized by a sol–gel method. The X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen adsorption–desorption measurements show that the Li3V2(PO4)3@CMK-3 nanocomposite exhibits the pure monoclinic structure and mesoporous morphology. Li3V2(PO4)3 has particle sizes of <50 nm, and are embedded in the mesoporous channels as well as well dispersed on the CMK-3 surface. Electrochemical measurements demonstrate that the Li3V2(PO4)3@CMK-3 nanocomposite shows significantly better rate capability and cycling performance than the bulk Li3V2(PO4)3. In the potential range of 3.0–4.3 V, the Li3V2(PO4)3@CMK-3 nanocomposite delivers high initial discharge capacity of 130.0 mAh g−1 at 0.2 C, and maintain an initial discharge capacity of 119.5 and 107.8 mAh g−1 at 5 C and 10 C, respectively. After 300 cycles, it can still retain a discharge capacity of 95.4 and 73.5 mAh g−1 at 5 C and 10 C, respectively. The good electrochemical performance for the Li3V2(PO4)3@CMK-3 nanocomposite are related to the special mesoporous structure, nanosized particles, and the existence of conductive carbon matrix, thus leading to improvement in electron and lithium ion diffusivity.
The electrochemical behaviour of N-arylmethylene and N-alkylmethine pyrrole monomers were investigated in their ability to be electropolymerised into polymer and co-polymer films with pyrrole using the techniques of cyclic voltammetry and scanning electron microscopy (SEM). N-substituted arylmethylene pyrrole monomers readily formed homopolymers by the oxidative electropolymerisation of pyrrole monomers by potentiostatic cycling in acetonitrile containing tetrabutylammonium perchlorate. The polymer films formed were brown in appearance and redox active, with the exception of the 1-((4-chlorophenyl)methyl)-1H-pyrrole (1d) which formed a pale yellow film lacking redox activity. The thickness of films produced calculated on the charge consumed followed the order 1e < 1b < 1h < 1i < 1f < 1a < 1g < 1c with the underlying morphology and thickness shown by SEM, for some monomers to mirror their structural characteristics. N-alkylmethine pyrrole monomers were found only to form copolymers with pyrrole after 20 scans of which only monomers 1m-1o were electrochemically active. Polymer 1 m, (D,L)-N-(1,2-dicarboxyethyl)-1H-pyrrole prepared from D,L-aspartic acid was shown capable of forming complexes with Cu+ and Cd2+ ions at a concentration of 1×10−4 M under an applied–ve field and to release the metal ion on stepping the potential to zero.
Thin hybrid electrolytes based on lithium-ion conducting ceramics with a few micrometers thickness have been studied in order to be practically applied to 12 V-class bipolar battery with liquid-free and separator-free. A cubic garnet-type Li7La3Zr2O12 (LLZ)-based hybrid electrolyte composed of LLZ particles coated with 4 wt% polyacrylonitrile (PAN)-based gel polymer electrolyte was prepared as the thin electrolyte layer, which reduced the internal resistance of LiMn0.8Fe0.2PO4(LMFP)/Li4Ti5O12(LTO) cells and enabled discharge at low temperatures. The conductivity of the LLZ-based hybrid electrolyte at 25°C was one order of magnitude higher than that of the LLZ solid electrolyte and comparable to that of the PAN-based gel polymer. The activation energy for ionic conductivity of the hybrid electrolyte was significantly smaller than that of the gel polymer electrolyte. The fabricated 12 V-class bipolar LMFP/LTO battery using the thin LLZ-based hybrid electrolyte layer exhibited good performance in terms of discharge rate capability, operating in the wide temperature range of −40°C to 80°C, and charge–discharge cycling comparable to those of conventional lithium-ion batteries.
In plug-in hybrid electric vehicles (PHEVs), the engine temperature declines due to reduced engine load and extended engine off period. It is proven that the engine efficiency and emissions depend on the engine temperature. Also, temperature influences the vehicle air-conditioner and the cabin heater loads. Particularly, while the engine is cold, the power demand of the cabin heater needs to be provided by the batteries instead of the waste heat of engine coolant. The existing energy management strategies (EMS) of PHEVs focus on the improvement of fuel efficiency based on hot engine characteristics neglecting the effect of temperature on the engine performance and the vehicle power demand. This paper presents a new EMS incorporating an engine thermal management method which derives the global optimal battery charge depletion trajectories. A dynamic programming-based algorithm is developed to enforce the charge depletion boundaries, while optimizing a fuel consumption cost function by controlling the engine power. The optimal control problem formulates the cost function based on two state variables: battery charge and engine internal temperature. Simulation results demonstrate that temperature and the cabin heater/air-conditioner power demand can significantly influence the optimal solution for the EMS, and accordingly fuel efficiency and emissions of PHEVs.
Binary Mn–Fe oxides with different Mn/Fe content ratios were prepared by anodic deposition. The deposited oxides were studied by in situ X-ray absorption spectroscopy (XAS) in 2M KCl solution during the charging–discharging process. The experimental results clearly confirmed that the oxidation states of both Mn and Fe changed back and forth with adjusting the applied potential, contributing to the pseudocapacitive characteristics of the binary oxides. It was also found that, within a potential range of 1V, because of Fe oxide addition the variation in the Mn oxidation state was increased from 0.70 (+3.25 to +3.95 for plain Mn oxide) to 0.81 (+3.12 to +3.93 for Mn90Fe10 oxide or +3.10 to +3.91 for Mn75Fe25 oxide), while the Fe oxide itself demonstrated an oxidation state shift of only 0.55. Accordingly, the optimum pseudocapacitance of the binary Mn–Fe oxide could be only achieved when the amount of Fe oxide was properly controlled. The highest specific capacitance of 255Fg−1 was obtained with a Mn/Fe atomic ratio of 90/10, while plain Mn oxide revealed a capacitance of only 205Fg−1.
The LiZn x Mn2−x O4 (x =0.00–0.15) cathode materials for rechargeable lithium-ion batteries were synthesized by simple sol–gel technique using aqueous solutions of metal nitrates and succinic acid as the chelating agent. The gel precursors of metal succinates were dried in vacuum oven for 10h at 120°C. After drying, the gel precursors were ground and heated at 900°C. The structural characterization was carried out by X-ray powder diffraction and X-ray photoelectron spectroscopy to identify the valance state of Mn in the synthesized materials. The sample exhibited a well-defined spinel structure and the lattice parameter was linearly increased with increasing the Zn contents in LiZn x Mn2−x O4. Surface morphology and particle size of the synthesized materials were determined by scanning electron microscopy and transmission electron microscopy, respectively. Electrochemical properties were characterized for the assembled Li/LiZn x Mn2−x O4 coin type cells using galvanostatic charge/discharge studies at 0.5C rate and cyclic voltammetry technique in the potential range between 2.75 and 4.5V at a scan rate of 0.1mVs−1. Among them Zn doped spinel LiZn0.10Mn1.90O4 has improved the structural stability, high reversible capacity and excellent electrochemical performance of rechargeable lithium batteries.
In this paper, Li3V2(PO4)3/C was synthesized using the carbon thermal reduction method. The electrochemical performance of Li3V2(PO4)3/C in a broad electrochemical window was studied. The fine structure of Li3V2(PO4)3/C after cycling in different charge and discharge ranges was investigated by X-ray powder diffraction (XRD) refinement, X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results show that the cycling stability of this material decreases with the increase of charge cut-off voltages. After cycling, the unit cell volume of Li3V2(PO4)3/C expanded irreversibly, in which the lengths of the Li(3)–O and V–O bonds became longer while those of Li(2)–O and Li(1)–O bonds became shorter. In the meantime, the amount of V5+ in the material increased and the carbon layer coated on the surface of the material was destroyed as the charge cut-off voltage was increased from 4.3 to 4.8V. It is therefore reasonable to infer that the changes in the crystal structure of Li3V2(PO4)3/C cause the poor cycling performance of Li3V2(PO4)3/C. This result provides a research idea for improving the cyclic performance of Li3V2(PO4)3/C in the future.
All electronic devices are plagued with 1/f noise originating from many causes. The most important factors contributing to 1/f noise in a semiconductor is believed to be recombination of carriers and their trapping at defects and impurity sites. Adsorption of moisture and electron acceptor molecules enhances the intensity of 1/f noise. Amazingly, some molecular species that strongly chelate to the semiconductor surface, suppress 1/f noise owing to passivation of the recombination sites. Thus in addition to sensitization, the dye adsorbed on the nanocrystallites plays a key role in mitigation of recombinations. For this reason dye-sensitized heterojunctions could also find application as low noise NIR photon detectors. Experiments conducted with oxide semiconductors (TiO2, ZnO, SnO2) indicate that the mode of binding of dyes at specific sites determines the extent to which the recombination and 1/f noise are suppressed. The transport of electrons in a nanocrystalline matrix is diffusive with a diffusion coefficient D depending on the trapping and detrapping processes. Thus passivation of trapping sites by the adsorbed dye is expected to increase the response time which can be expressed as τ ∼ L 2/D, where L =thickness of the nanocrystalline film. Measurement techniques and construction of a dye-sensitized NIR photon detector will be discussed.
The BBC Subjective Well-being scale (BBC-SWB) is a recently developed questionnaire designed to measure people’s subjective experiences across the wide breadth of domains commonly included in definitions of well-being. Although it has previously been shown to be a reliable and valid measure of subjective well-being in the general population with good psychometric properties, a limitation of the initial version was that it was developed using responses on a 4-point Likert-style scale. This paper presents the psychometric properties, validity and reliability of a revised version of the scale conducted using 5-point Likert-style responses and tests the hypothesis that the scale measures three underlying dimensions of well-being; psychological; physical health; and relationships.
A severe drought now affecting extensive areas of Brazil [see Research Trends, p. 12 in this issue], in particular the northeast, may be partially solved by a solar approach.
Hot and arid countries are all too frequently beset with the many tragedies arising from poverty. A key aspect relating to poverty is the lack of low-cost sources of energy, other than that of locally scavenged organic materials such as wood. However, for the most part, even when they have installed such energy sources as power stations, lack of a complete national energy distribution system severely restricts efforts to escape the poverty trap. PV systems have been playing a key role in overcoming these drawbacks; none more so than in the countries of the Indian subcontinent.
The present research tested the hypothesis that false recognition in confabulating patients results, at least in part, from sustained processing of irrelevant information about test items. Thus, we predicted that false recognition would be reduced if cognitive resources available for such a processing are experimentally reduced. Two experiments provided evidence consistent with this proposal. In Experiment 1, confabulating patients exhibited lower false recognition in a divided attention (DA) compared to a full attention (FA) retrieval condition. The opposite trend was observed in non-confabulating patients with comparable memory and executive deficits and normal controls. In Experiment 2, in a Deese–Roediger–McDermott paradigm, confabulating patients exhibited lower false recognition to lures that were unrelated to the studied words in the DA compared to the FA retrieval condition, but unvaried levels of false recognition to critical lures. In contrast, false recognition to both unrelated and critical lures increased in non-confabulating patients and normal controls in the DA compared to the FA condition. These results are consistent with the hypothesis that an excessive processing of task-irrelevant memories at retrieval may contribute to false recognition in confabulating patients.
An organometallic compound of ferrocene is first investigated as a promising anode for lithium-ion batteries. The electrochemical properties of ferrocene are conducted by galvanostatic charge and discharge. The ferrocene anode exhibits a high reversible capacity and great cycling stability, as well as superior rate capability. The electrochemical reaction of ferrocene is semi-reversible and some metallic Fe remains in the electrode even after delithiation. The metallic Fe formed in electrode and the stable solid electrolyte interphase should be responsible for its excellent electrochemical performance.
An innovative method is applied to investigate anode swelling during electrochemical processes in commercial lithium-ion batteries. Cathode surface is partially covered with a piece of paste to block the transportation of lithium ion from active material during charging/discharging, and the corresponding part on the anode film shows no formation of Li-graphite compounds during different electrochemical processes, which is confirmed by XRD analysis. The increases of anode thickness within and outside lithiated zone are measured, and defined as electrochemical swelling and physical swelling respectively. The microscopic lattice expansion of graphite due to lithiation process correlates to mesoscopic electrochemical swelling synchronically, while physical swelling tends to decrease steadily with time. The relationship among the microscopic stress due to lithium-ion intercalation, the mesoscopic stress resulting in anode swelling, and the macroscopic rippling of pouch cell after a large number of cycle test, is analyzed and correlated in terms of stress evolution across different scales, and suggestions for solving anode swelling are provided.
We have prepared a 4.8V voltage cathode, Li(Ni0.5Mn1.5)O4 using the polymer polyvinylpyrrolidone (PVP) as precursor at temperatures ranging from 700 to 750°C for 6h in air. The Rietveld refined X-ray diffraction patterns of Li(Ni0.5Mn1.5)O4 showed a spinel type structure with a lattice parameter value of ∼8.174(2)Å. The Scanning Electron Microscope (SEM) images showed particle size in the range, ∼100–3000nm. The surface area of the prepared powders was characterized by the Brunauer–Emmett–Teller (BET) technique. Cathodic electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic cycling (GC) in the range 3.5–5.0V vs. Li/Li+ at ambient temperature. CV studies showed a minor peak at ∼4.0V due to the Mn3+/4+ redox couple, and main anodic/cathodic peaks at 4.75/4.6V and 4.8/4.7V corresponding to the Ni2+/4+ redox couples. The GC studies were carried out at the current rates (C/4.5) 30mAg−1 and (C/1.2) 120mAg−1, at room temperature. The reversible capacities of all samples prepared at 700–750°C are in the range, 92–130 (±3)mAhg−1 at the end of 15th cycle. Impedance studies were carried out on a selected cell.
Recent years, as a competitive anode material for lithium ion batteries (LIBs), tungsten disulfide (WS2) has attracted significant attention for its high theoretical capacity, abundant resources and low cost, but how to improve the cycle stability and reversible capacity is still an important research subject. In this work, stable metallic WS2 anchored on carbon fiber cloth was fabricated as flexible anode for LIBs. The transversal displacement of S atoms in WS2 was induced by incorporation of N atoms, and the stability of metallic phase WS2 was ensured by the formation of N-W covalent bonds. The results of electrochemical measurement and dynamics analysis demonstrate that the incorporation of metallic phase could not only reduce the initial discharge capacity loss, but also improve the reversible capacity than traditional semi-conducting phase WS2.
A coupling of structural and thermodynamic fluctuations in the course of various-type insertion processes is investigated with a combination of Gibbsian statistics and the information theory approach. It is shown that the coupling makes it possible to restore (at least partially) the information, inaccessible from experimental tests. This enables one to make physically reasonable predictions under limited information on the system.
The Easterlin paradox (Easterlin, in: Paul, Reder (eds) Nations and household in economic growth: essay in honor of Moses Abramovitz, Academic Press, New York, 1974), for many researchers, is the starting point of studies on the relationship between happiness and GDP and states that after reaching a certain level of income, happiness decreases instead of increasing. The Comparison Theory (Schyns in Soc Indic Res 43:3–2, 1998) and Van Praag and Kapteyn’s (Eur Econ Rev 4(1):33–62, 1973) also show that if an individual’s income increases, it is not related into an increase in income satisfaction and the same mechanism applies to happiness, depending on several aspects. Today and in the future not only the growth of income but also the achievement of happiness have become a political objective and politicians will direct their policy towards these objectives. Furthermore, the interpretation of the relation between GDP and happiness remains one of the most recurring controversial errors in the framework and methodology used, although understanding of what makes people happy helps politicians to direct their policies. In Italy the Easterlin paradox seems to have found confirmation, but not a historical explanation also because the study of the relation between GDP and happiness, confirming the need to use appropriate indicators in the study of the relationship between economic development and happiness, for instance alternative national accounts indicators for GDP, or antidepressant expenditure for (un)happiness. The paper suggests “to define happiness before investigating it”, proposing a definition of happiness that also indicates an appropriate methodology to analyze if people can be happy in the economic system.
Ad hoc networks are characterized by fast, dynamic changes in the topology of the network. Introduction of new routing algorithms requires a deep and reliable evaluation process. In this paper, we describe an interactive flexible ad hoc simulator (IFAS) that presents a modern and novel approach to the family of ad hoc simulators. This simulator supports unique viewing, debugging, tuning and interactive capabilities that shorten significantly the design and debug process of new algorithms. The development of the IFAS is ongoing; however, we consider this new simulator as an innovative tool that will supplement traditional simulators.
Failures of electrochemical cells caused by internal shorts still are an important issue to be faced by the cell manufacturers and their customers. A major cause for internal shorts are contaminated electrode foils. These contaminations have to be detected securely via a non-destructive inspection technique integrated into the electrode manufacturing process. While optical detection already is state of the art, infrared detection of particles finds a new field of application in the battery electrode manufacturing process. This work presents two approaches focusing on electrode inspection by electromagnetic radiation (visible and infrared). Copper foils with a carbon based coating were intentionally contaminated by slivers of aluminum and copper as well as by abraded coating particles. Optical excitation by a flash and a luminescent lamp was applied at different angles in order to detect the reflected visible radiation. A laser impulse was used to heat up the specimen for infrared inspection. Both approaches resulted in setups providing a high contrast between contaminations and the coated electrode foil. It is shown that infrared detection offers a higher security thanks to its reliance on absorbance and emissivity instead of reflectivity as it is used for optical detection. Infrared Detection offers a potential since it is hardly influenced by the particle’s shape and orientation and the electrode’s waviness.
Micro-solid oxide fuel cells (micro-SOFC) are predicted to be of high energy density and are potential power sources for portable electronic devices. A micro-SOFC system consists of a fuel cell comprising a positive electrode-electrolyte-negative electrode(i.e. PEN) element, a gas-processing unit, and a thermal system where processing is based on micro-electro-mechanical-systems fabrication techniques. A possible system approach is presented. The critical properties of the thin film materials used in the PEN membrane are discussed, and the unsolved subtasks related to micro-SOFC membrane development are pointed out. Such a micro-SOFC system approach seems feasible and offers a promising alternative to state-of-the-art batteries in portable electronics.
A novel ternary tungsten disulfide (WS2)/copper oxide (CuO)/single-wall carbon nanotubes (SWCNT) porous laminated hybrids are fabricated with the aid of electrostatic interaction and vacuum filtration. In which, the layered WS2 sheets are spaced by high electrochemical active CuO nanosheets and conductive SWCNT and form a unique sandwich-like porous structures. When used as a lithium ion batteries anode, it demonstrates high reversible specific capacity of 962.4mA h g−1 at 0.1A g−1 after 100 cycles and excellent rate capability, a reversible specific capacity of 418.1mA h g−1 even at a high rate current density of 2A g−1. The unique assembled WS2/CuO/SWCNT porous hybrids not only show the improved electrical conductivity, but also provide efficient charge transport channels for electrolyte penetration and sustain for the volume variation during the lithiation and delithiation. These synergistic effects significantly improve the electrochemical performances. The synthesis approach presented here would be extended to the other layered-based composites for energy applications.
The significant phase change between gaseous and crystalline oxygen deteriorates the performance of lithium–air batteries. Here the authors report a battery with a cathode consisting of Li2O and Co3O4 nanocomposites, which displays stable cyclability and high energy density, without involving any gas evolution.
The synthesis of NaxKyFe[Fe(CN)6] through a simple co-precipitation method and the application of these nanoparticles in sodium-ion batteries are presented. K1.90Fe[Fe(CN)6] with a cubic structure shows low volumetric change during electrochemical cycling. It is clarified by ex-situ X-ray diffraction and cyclic voltammetry curves that K+ influences the intercalation sites of the neighboring Na+. More significantly, this hexacyanoferrate delivers a high capacity of 137.0mAhg−1 at a current density of 14mAg−1 and superior cyclability with 94% capacity retention after 120 cycles, showing great promise for sodium-ion battery applications.