batterydata/paper-abstracts huggingface dataset:
Li/Si undergoes significant softening in the form of rapid decreases in elastic modulus and yield stress as lithium concentration increases. To investigate how this lithiation-induced softening affects the fracture behavior of electrodes, we formulate a J-integral for coupled mechanical deformation and mass diffusion processes. This measure is used to analyze mechano-diffusional driving forces for fracture through simulations using a mixed finite element framework. Calculations show that under tensile loading, Li accumulates in front of crack tips, leading to an anti-shielding effect on the energy release rate. For a pre-cracked Li/Si thin-film electrode, it is found that the driving force for fracture is significantly lower when the electrode is operated at higher Li concentrations – a result of more effective stress relaxation via global yielding. The results indicate that operation at higher concentrations is an effective means to minimize failure of thin-film Li/Si alloy electrodes. A design map for avoiding failure is developed.
This work describes the electrocatalytic properties of a carbon composite electrode (CCE) modified with Prussian blue (PB) nanoparticles (NPs) for the electrocatalytic oxidation of pyridoxine (PN). The morphology of the PBNP-modified CCE was characterized by scanning electron microscopy (SEM). The mechanism and kinetics of the catalytic oxidation reaction of PN were monitored by cyclic voltammetry and chronoamperometry. The rate-limiting step of the charge transfer reaction was found to be a one-electron abstraction. The value of α, k, and D were calculated as 0.66, 6.7×104 M−1 s−1, and 1.88×10−5 cm2 s−1, respectively. The modified electrode showed electrocatalytic activity toward the oxidation of PN and was used as an amperometric sensor. The sensor exhibited good linear response for PN over the concentration ranges 5–69 and 1–80μM with detection limits of 0.51 and 0.87μM, and sensitivities of 0.97 and 0.673AM−1 cm−2 in batch and flow conditions, respectively. Some important advantages such as simple preparation, fast response, good stability, and reproducibility of the sensor for the amperometric determination of PN were achieved.
Oxides of compositions Li(1−0.5x)Fe(1.5x+1)Mn(1−x)O4 (0≤1−x≤1) with a spinel structure have been characterized by XRD analysis and Mössbauer spectroscopy. The surface properties of the materials have been studied by OCP, pHz and XPS measurements. The influence of the substitution of Fe by Mn on the electrocatalytic activity of the electrodes has been analyzed in terms of Tafel slopes and proposed cationic distribution. The oxygen evolution reaction depends on both OCP and pHz, and it is very sensitive to the iron/manganese ratio in the octahedral sites of the spinel structure.
In this work, we synthesized nano-particles (20–80nm) of Li2MnO3 using the self-combustion reaction and studied the electrochemical activity of electrodes prepared from this nano-material at 30, 45, and 60°C. It was shown that the first Li-extraction from nano-Li2MnO3 occurs at much lower potentials (by 180–360mV) in comparison with micron-sized Li2MnO3 electrodes. This can be associated with the higher surface-to-volume ratio, much shorter the diffusion path and the increased surface concentration of the electrochemically active sites. On the basis of magnetic susceptibility studies of nano-Li2MnO3 we proposed a model of disordered surface layer, containing Mn3+ or Mn2+ ions, both at low spin state, at the surface of these nano-particles. From the results of structural analysis (by X-ray and electron diffraction and vibrational Raman spectroscopy) of galvanostatically cycled nano-Li2MnO3 electrodes in Li-cells we came to a conclusion of partial transition of layered LiMO2 to spinel-type ordering.
LiV3O8, synthesized from V2O5 and LiOH, by heating of a suspension of V2O5 in a LiOH solution at a low-temperature (100–200°C), exhibits a high discharge capacity and excellent cyclic stability at a high current density as a cathode material of lithium-ion battery. The charge-discharge curve shows a maximum discharge capacity of 228.6mAhg−1 at a current density of 150mAg−1 (0.5C rate) and the 100 cycles discharge capacity remains 215mAhg−1. X-ray diffraction indicates the low degree of crystallinity and expanding of inter-plane distance of the LiV3O8 phase, and scanning electronic microscopy reveals the formation of nano-domain structures in the products, which account for the enhanced electrochemical performance. In contrast, the LiV3O8 phase formed at a higher temperature (300°C) consists of well-developed crystal phases, and coherently, results in a distinct reduction of discharge capacity with cycle numbers. Thus, an enhanced electrochemical performance has been achieved for LiV3O8 by the soft chemical method via a low-temperature heating process.
State-of-health evaluation of lithium ion batteries is one of the key challenges to construct efficient battery system with enhanced performance. In this paper, we demonstrate a facile evaluation method which is based on the voltage stabilization behaviour during relaxation. A second-order equivalent circuit is employed to describe the voltage relaxation. By simulating the voltage relaxation curves, the characteristic parameters that can distinguish the ohmic, activation and concentration depolarizations are acquired. The obtained parameters are sensitive to electrochemical states, which provide comprehensive evaluation to the state-of-health of batteries and aging mechanism analysis. As an example, the proposed method identifies two aging stages of Li(Ni1/3Co1/3Mn1/3)O2/graphite pouch cells during accelerated aging. Namely, a loss of lithium inventory in the first stage of aging, and the loss of active material in the next stage. Postmodern analysis including X-ray diffraction and high-resolution transmission electron microscope well agrees with the voltage relaxation simulation. The proposed state-of-health evaluation method is non-destructive and accessible for on-board aging diagnosis, which is of great significance for developing better battery management system.
Polypyrrole films containing gold nanoparticles (PPy/Au) were electrosynthesized on a glassy carbon electrode. This was done by applying a constant current of 1.43mAcm−2 in solutions containing colloidal Au particles and pyrrole monomer. A chloroaurate medium with a citrate/tannic acid reducing/protection agent was employed for generating the Au colloids. The PPy/Au films were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Also, electrochemical behaviors of the PPy/Au films were characterized by cyclic voltammetry (CV) and AC impedance measurements. Experimental results demonstrate that PPy/Au has greater conductivity and better stability than PPy. The effect of incorporated Au nanoparticles in PPy matrix was studied and the mechanism was suggested.
Lead-foam grids have been prepared by electrodepositing lead on a copper-foam substrate that has good conductibility and a symmetrically three-dimensional reticulated structure. VRLA batteries with lead foam as the negative electrode current collector material have been fabricated; the effects of the lead foam on the specific capacity, the active material utilization efficiency and the negative active material transformation process of the VRLA batteries have been studied. The results show that a lead-foam grid has a bigger specific surface area than a cast grid. The charge voltage of a VRLA battery with a lead-foam negative electrode is significantly lower than that of a VRLA battery with a cast grid electrode during a charge process. The discharge capacity, the mass specific capacity, and the active material utilization efficiency of a VRLA battery with a lead-foam electrode can be greatly improved at different states of discharge. The EIS research revealed that a lead-foam negative electrode has higher electrochemical reactivity. Observed by means of a scanning electron microscope, it was found that the spongy Pb crystals at a lead-foam grid negative electrode are smaller than that of a cast grid negative electrode at a state of charge; while the PbSO4 crystals are smaller than that of a cast grid negative electrode at a state of discharge.
Phosphorus-based anode materials are of considerable interest for grid-scale energy storage systems due to their high theoretical capacity. Nevertheless, the low electrical conductivity of P, large volume changes during cycling, and highly-reactive phosphide surface are hindering their potential applications. Herein, outstanding long-term cycling stability with high retained potassium storage capacity (213.7 mA h g−1 over 2000 cycles) was achieved via the introduction of an alternative potassium bis(fluorosulfonyl)imide (KFSI) salt and by using a layered compound (GeP5) with a high phosphorus concentration as anode material. Fourier transform infrared spectroscopic mapping results suggest that KFSI salt helps to form an uniform solid electrolyte interphase (SEI) layer and reduces the side reactions at the electrode/electrolyte interface, thus enhancing the cycling performance. In-operando synchrotron X-ray diffraction analysis has revealed the synergistic reaction mechanisms of the K-P and K-Ge reactions. These findings indicate the enormous potential of phosphorus-based anodes for high-performance potassium ion batteries and can attract broad interest for regulating the SEI layer formation through manipulating the salt chemistry.
Silver vanadium oxide (SVO, Ag2V4O11) was synthesized in solid-state reactions from silver carbonate and silver metal powder starting materials with vanadium oxide (V2O5) as the vanadium source. These powders were prepared as primary cathode materials for lithium batteries. Thermal analyses of stoichiometric mixtures of V2O5 and silver sources were used to elucidate the mechanism of Ag2V4O11 formation. V2O5 reacts with Ag2CO3 in a two step decomposition/combination (DC) reaction. Weight gain measured by TGA during the reaction of Ag(0)+V2O5 in O2 indicated the formation of Ag2V4O11. XRD analysis of the synthesis products of the Ag(0)+V2O5 reaction indicated the formation of AgV2O5 under inert atmosphere and Ag2V4O11 under oxidizing (air or O2) conditions. The surface area and morphology of the materials were strongly influenced by the synthesis method, linked to the parameters of time, temperature, and reaction atmosphere. The electrochemical performance of the SVO cathode material also depended on the synthesis method, where SVO prepared from the DC reaction mechanism yielded improved long-term performance.
Using a combined electrochemical and mechanical manipulation technique, we compared the equilibrium and non-equilibrium oxidation processes and states of tantalum. Experimentally, a setup was developed with an electrochemical system attached to a sliding mechanical configuration capable of friction force measurement. The surface chemistry of a sliding surface, i.e., tantalum, was modified through the electrolyte. The mechanically applied force was fixed and the dynamics of the surface was monitored in situ through a force sensor. The formation of non-equilibrium oxidation states of tantalum was found in oxidation limiting environment of acetic acid. An oxidative environment of deionized water saturated with KCl was used as comparison. We proposed a modified Arrhenius–Eyring equation in which the mechanical factor was considered. We found that the mechanical energy induced the non-stable-state reactions leading to metastable oxidation states of tantalum. This equation can be used to predict mechanochemical reactions that are important in many industrial applications.
Cycling of graphite in lithium-ion batteries is reversible except for the first-cycle, where some charge is “lost” due to irreversible side reactions. The irreversible charge loss of different TIMREX® graphites was found to be a linear function, both of their specific BET surface areas and of the double-layer capacitance of electrodes manufactured from these graphites. Nitrogen-adsorption measurements and differential-porosity calculations indicate that the pore structure of the graphite particles mainly consists of mesopores (2–50nm). The surface area of these mesopores is part of the electroactive surface area determined by impedance spectroscopy, and contributes to the irreversible capacity of the graphite negative electrode in the first-cycle.
Vanadium pentoxide (V2O5) thin films grown by rf-sputtering have been studied as a function of two growth parameters, O2 content and substrate temperature, which influence importantly their structural, as well as their electrochemical and electrochromic properties. The increase in O2 content appears to result in an increase of the grain size of the films, while the increase in substrate temperature leads in platelets perpendicular to the substrate, which enhance the porosity of the films. Films with low O2 content (3%) and films grown at a substrate temperature of 300°C, present enhanced charge storage properties of 553mA h g−1 and large transmittance modulation ability. On the contrary, high O2 content (11%) and a substrate temperature of 150°C lead to improved coloration efficiency (at λ=400nm), reaching values of 84.5 and ∼132cm2C−1, respectively. These findings are discussed in terms of structural and morphological changes occurring during the two parameters studied.
Amplification of influenza A virus gene segments by reverse transcription-polymerase chain reaction (RT-PCR) can be combined with enzymatic digestion to reveal unique restriction fragment length polymorphisms specific for H1N1 and H3N2 subtype viruses. We have used the method to provide a rapid, specific and reproducible identification of the genotype of high-growth influenza reassortants derived from A/Puerto Rico/8/34 (PR8). Digestion of the gene segments amplified from wild-type viruses, PR8 and reassortants at sites unique to either the wild-type strain or to PR8 provided positive, unambiguous identification of the origin of each of the internal genes, and distinguished the internal genes of both H1N1 and H3N2 strains from those of PR8. This method has also permitted us to quickly confirm that reassorting has occurred and to optimize the selection of reassortant clones with maximum number of PR8 internal genes. Since the method can detect 1–10% of a second strain in a mixed population, the method can also be used to detect samples containing more than one viral subtype and to assess the purity of influenza viruses used for manufacturing vaccines.
The normal physiological function of the prion protein PrPC remains unknown. Here, the authors report that PrP knockout mice show altered behavior in two olfactory tasks and that PrP deficiency affects oscillatory activity in the olfactory bulb. Both the behavioral and electrophysiological phenotypes could be rescued by transgenic neuronal-specific expression of PrPC.
Cancer diagnosis and treatment can generate substantial distress for both survivors and their family caregivers. The primary aim of this investigation is to test a model of dyadic interdependence in distress experienced by cancer survivors and their caregivers to determine if each influences the other.
Direct methanol fuel cells (DMFCs) within all types of fuel cells are the most viable alternative to lithium-ion batteries in the portable application, and recently attracted much attention. This review provides a comprehensive overview of the passive DMFC barriers viz. methanol crossover, slow kinetics, water management, heat management, species management, durability and stability and cost for commercialization. Furthermore, it focuses on different approaches to overcome discussed barriers of passive DMFC. It is shown that the critical challenge regarding to minimize methanol crossover through the membrane using various hybrid membranes and methanol transport barrier so that the cell performance can be maximized. Regarding to reduce the catalyst cost with better kinetics, it is expected for developing non noble catalyst for passive DMFC. The challenges related to the operating temperature of passive DMFC is the selection methanol concentration, current density, ambient temperature, air humidity, cell orientation, membrane thickness, cell design, etc. which affects the cell performance. The several methods related to the water management layer deals with transport of the water produced on the cathode to the anode through the membrane and the cathode with minimum water flooding.
The concentration of ions in the electrolyte solution in lithium ion batteries changes during operation, reflecting the resistance to ion migration and the positions of diffusion barriers. The change causes various negative effects on the performance of batteries. Thus, it is important to elucidate how the concentration changes during operation. In this work, the concentration change of ions in the electrolyte solution in deep narrow spaces in a realistic battery was studied by in situ ultrafine microprobe Raman spectroscopy. Graphite composite and LiCoO2 composite electrodes, which are the most commonly used electrodes in practical batteries, were placed facing each other and their distance was set to 80μm, which is close to the distance between electrodes in practical batteries. After repeated charge/discharge cycles, the concentration of ions increased and decreased greatly during charging and discharging, respectively. The maximum concentration was more than three-times higher than the minimum concentration. The rate of changes in concentration increased almost linearly with increase in current density. The results have important implications about concentration changes of ions occurring in practical batteries.
This work investigates the thermal release of mercury from phosphor powder of spent fluorescent lamps. The treatment conditions and the ability of various reducing agents (primarily sodium borohydride) to lower the overall heating temperature required to improve the release of Hg have been evaluated. Hg species in samples were monitored in a thermal desorption atomic absorption spectrometer system, and total mercury was analyzed in a cold vapor atomic absorption spectrometer. Sodium borohydride was the best reducing agent among the ones studied. However, citric acid presented a high capacity to weaken mercury bonds with the matrix. When the sample was crushed with sodium borohydride for 40min in a mass ratio of 10:1 (sample:reducing agent) and submitted to thermal treatment at 300°C for 2h, the concentration of mercury in a phosphor powder sample with 103mgkg−1 of mercury reached 6.6mgkg−1.
Recently, compressed Sensing (CS) has theoretically been proposed for more efficient signal compression and recovery. In this paper, the CS based algorithms are investigated for Query by Example Video Retrieval (QEVR) and a novel similarity measure approach is proposed. Combining CS theory with the traditional discrete cosine transform (DCT), better compression efficiency for spatially sparse is achieved. The similarity measure from three levels (frame level, shot level and video level, respectively) is also discussed. For several different kinds of natural videos, the experimental results demonstrate the effectiveness of system by the proposed method.
The lithium–sulfur batteries show the great potential to be the most promising candidate for high energy applications. However, the shuttling of soluble polysulfides deteriorates the battery performance tremendously. To suppress the diffusion of soluble polysulfides, diatomite that has abundant natural three-dimensional ordered pores is incorporated into the cathode to trap polysulfides. The composite cathode material (S-DM-AB for short), including sulfur (S), diatomite (DM), and acetylene black (AB) is prepared by an impregnation method. For comparison, another composite cathode material (S-AB for short) including sulfur and acetylene black is also prepared by the same method. The battery with S-DM-AB composite cathode material delivers a discharge capacity of 531.4 mAh/g after 300 cycles at 2 C with a capacity retention of 51.6% at room temperature. By contrast, the battery with S-AB composite cathode material delivered a capacity of only 196.9 mAh/g with a much lower capacity retention of 18.6% under the same condition. The addition of diatomite in the cathode is proved to be a cheap and effective way to improve the life time of the lithium sulfur batteries.
Aims/Hypothesis This study aimed to examine hand disorders, symptoms, overall hand function, activities of daily living (ADLs), and life satisfaction in elderly men with type 2 diabetes mellitus (DM), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT). Methods Subjects were interviewed and evaluated with a battery of clinical and laboratory tests, including hand assessment, and a questionnaire. Results HbA1c differed between groups (highest in DM, especially in long-term DM). Limited joint motion (LJM), for example, prayer sign and Dupuytren's contracture, was most common in individuals with DM, followed by individuals with IGT, as compared to those with NGT. Vibrotactile sense was impaired symmetrically in the index and little fingers in DM. However, there were no differences for sensibility, dexterity, grip strength, and cold intolerance between groups. Individuals with long-term (>15 years) DM were more affected regarding sensibility and ADL than individuals with short-term DM, who had more sleep disturbances. ADL difficulties were less among IGT subjects. Vibrotactile sense showed correlations with Semmes–Weinstein monofilament test and static two-point discrimination. Conclusions/Interpretation Dupuytren's contracture and impaired vibrotactile sense in finger pulps occurred in patients with DM but not in those with IGT, although LJM occurred in both IGT and DM patients. A longer duration of DM was associated with more severe neuropathy and ADL difficulties. Life satisfaction was high, and hand disorders did not have a significant impact on ADL.
In response to the first bluetongue outbreak in Belgium a monitoring programme was started at the end of August 2006 to identify possible vectors transmitting the disease. Black light traps were deployed at 36 outbreak sites and captured 1959 Culicoides specimens belonging to 16 different species. Eighty four percent of the biting midges captured belonged to the C. obsoletus complex, among them C. obsoletus s.s., C. dewulfi and C. scoticus, three suspected bluetongue vectors. The Veterinary and Agrochemical Research Centre detected viral RNA in pools of individuals belonging to this complex. Culicoides pulicaris, a potential bluetongue vector in Italy, should yet not be excluded as a possible vector in Belgium as this species was frequently found around outbreak sites, notwithstanding this species is not easily captured with the trapping techniques used during this survey.