batterydata/paper-abstracts huggingface dataset:
We report here the performance of FeSb2 used as negative electrode for Li-ions batteries. A capacity of 400mAhg−1 and 3500mAhcm−3 can be retained after 10 cycles at a C/10 cycling rate. We studied in particular the electrochemical mechanism during the first discharge of the FeSb2/Li battery. Both Mössbauer spectroscopy (57Fe and 121Sb) and in situ XRD studies show the formation of an unknown fcc-phase during the first step. A second step shows the conversion process leading to Li3Sb at the end of the discharge. The structure of the intermediate new phase Li4FeSb2 is isotype to the face-centered-cubic Li3Sb phase in which one Fe atom is substituted by two Li atoms.
This paper provides a detailed review of renewably driven hydrogen systems and modeling approaches applicable to these systems that have been reported over the last two decades. Several renewable energy technologies, including solar photovoltaic, wind, and hydro, have been considered as the power source in these reports. Storage is an important aspect of hydrogen systems, and options for this are summarized here. Utilization systems include fuel cells as well as a variety of thermal uses. Some of the reported studies have addressed residential applications whereas others were related to commercial scale systems. This paper particularly emphasizes aspects of modeling of the various components for the renewable hydrogen system. Based on the literature on this area, conclusions are provided on the current understanding as well as future work related to this topic.
The EU RoHS Directive (2002/95/EC of the European Parliament and of the Council) bans the placing of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants on the EU market. It necessitates methods for the evaluation of RoHS compliance of assembled electronic equipment. In this study mounted printed circuit boards from personal computers were analyzed on their content of the three elements Cd, Pb and Hg which were limited by the EU RoHS directive. Main focus of the investigations was the influence of sample pre-treatment on the precision and reproducibility of the results. The sample preparation steps used were based on the guidelines given in EN 62321. Five different types of dissolution procedures were tested on different subsequent steps of sample treatment like cutting and milling. Elemental analysis was carried out using ICP–OES, XRF and CV–AFS (Hg). The results obtained showed that for decision-making with respect to RoHS compliance a size reduction of the material to be analyzed to particles ⩽1.5mm can already be sufficient. However, to ensure analytical results with relative standard deviations of less than 20%, as recommended by the EN 62321, a much larger effort for sample processing towards smaller particle sizes might be required which strongly depends on the mass fraction of the element under investigation.
Background 22q11DS is a multiple anomaly syndrome involving intellectual and behavioral deficits, and increased risk for schizophrenia. As cognitive remediation (CR) has recently been found to improve cognition in younger patients with schizophrenia, we investigated the efficacy, feasibility, and fidelity of a remote, hybrid strategy, computerized CR program in youth with 22q11DS. Methods A longitudinal design was implemented in which 21 participants served as their own controls. Following an eight month baseline period in which no interventions were provided, cognitive coaches met with participants remotely for CR via video conferencing three times a week over a targeted 8month timeframe and facilitated their progress through the intervention, offering task-specific strategies. A subset of strategies were examined for fidelity. Outcomes were evaluated using a neurocognitive test battery at baseline, pre-treatment and post-treatment. Results All participants adhered to the intervention. The mean length of the treatment phase was 7.96months. A moderately high correlation (intraclass correlation coefficient, 0.73) was found for amount and type of strategies offered by coaches. Participants exhibited significant improvements (ES=.36–.55, p≤.009) in working memory, shifting attention and cognitive flexibility. All significant models were driven by improvements in pre to post-treatment scores. Conclusions Based on our preliminary investigation, a remote, hybrid strategy, computerized CR program can be implemented with 22q11DS youth despite geographic location, health, and cognitive deficits. It appears effective in enhancing cognitive skills during the developmental period of adolescence, making this type of CR delivery useful for youth with 22q11DS transitioning into post-school environments.
Carbonaceous materials ranging from soft carbons of moderate nitrogen content (up to 2.5wt.%) to typical hard carbons with an excess of nitrogen (up to 6wt.%) were produced by carbonisation at 1050°C of coal-tar pitch (CTP)—polyacrylonitrile blends with various ratio of the components. The resultant carbons were characterised by elemental analysis, optical and transmission electron microscopy (TEM), X-ray diffraction, X-ray photoelectron spectroscopy and sorption of nitrogen and carbon dioxide. The electrochemical lithium insertion has been investigated in these carbons by a galvanostatic technique, using carbon/lithium two-electrode cells. Independently of the nitrogen content, the electrochemical performance of the soft carbons is comparable. The nitrogen enriched hard carbons demonstrate a relatively low value of reversible capacity, due to the absence of available nanopores. On the other hand, the irreversible capacity increases with the proportion of nitrogen, especially in the form of pyridinic groups. The lone pair of electrons contribute to the trapping of solvated lithium cations on these groups which act as active sites for the electrolyte decomposition during the first reduction, leading to an enhanced irreversible capacity.
The increasing amount of PV (photo-voltaic) power plants comes along with an increased instability in the power grid due to the high uncertainty of the PV power production. As a stabilizing measure, grid operators introduce regulations on the injected power profiles comprising the obligation to declare in advance the predicted power production as well as penalties which apply in case these previously declared production profiles were not respected. In order to meet these regulations power plant owners are forced to invest into expensive storage capacities. In this work an algorithm is proposed which allows to determine the optimal battery size that maximizes the to-be-expected revenue of such an installation for a given regulative framework. Moreover the scheme explicitly takes into account the uncertainty in the PV power production and it provides guaranteed lower bounds on the to-be-expected revenue at a configurable probability. The underlying method allowing to achieve these objectives is a randomized algorithm. The principle of this method is to compute probabilistic guarantees for respecting a binary constraint, considering only a limited number of uncertainty scenarios.
Background Angelman syndrome (AS) is a rare neurological disorder characterized by severe developmental disability, communication impairment, elevated seizure risk, and motor system abnormalities. Aims The aims of this study were to determine the feasibility of social scene eye tracking and pupillometry measures in individuals with AS and to compare the performance of AS participants to individuals with idiopathic Autism Spectrum Disorder (ASD) and typically developing controls (TDC). Methods and procedures Individuals with AS and age- and gender- matched controls completed a social eye tracking paradigm. Neurobehavioral characterization of AS participants was completed via a battery of psychological testing and caregiver behavioral evaluations. Outcomes and results Eight of seventeen recruited AS participants completed the eye tracking paradigm. Compared to TDC, AS subjects demonstrated significantly less preference for social scenes than geometric shapes. Additionally, AS subjects showed less pupil dilation, compared to TDC, when viewing social scenes versus geometric shapes. There was no statistically significant difference found between AS and ASD subjects in either social eye tracking or pupillometry. Conclusions and implications The use of eye tracking and pupillometry may represent an innovative measure for quantifying AS-associated impairments in social salience.
A new 1D lithium-ion cell electrode model is presented, which, for the first time, considers the electrochemical coupling between particles of a real particle size distribution obtained from tomography data. It does so without actually resolving the 3D electrode microstructure in the model, but by including all necessary information in a homogenized manner, using microstructure data from high-resolution X-ray tomography. Additionally, the transport of lithium through the solid-electrolyte interphase (SEI) is considered. The effects of the particle–particle coupling are shown for a graphite negative electrode from a cylindrical high-power cell. The extended homogenized 1D porous electrode model provides an explanation for the vanishing plateaus in the graphite potential curve with increasing charge or discharge rates. This effect is not covered by state-of-the-art models.
We sought to determine the effects of varying the perceptual demands of a suprapostural visual task on the postural activity of children with developmental coordination disorder (DCD), and typically developing children (TDC). Sixty-four (32 per group) children aged between 9 and 10 years participated. In a within-participants design, each child performed a signal detection task at two levels of difficulty, low (LD) and high difficulty (HD). During performance of the signal detection tasks we recorded positional variability of the head and torso using a magnetic tracking system. We found that task difficulty had a greater effect on task performance among the TDC group than among children with DCD. Overall positional variability was greater the DCD group than in the TDC group. In the TDC group, positional variability was reduced during performance of the HD task, relative to sway during performance of the LD task. In the DCD group, positional variability was greater during performance of the HD task than during performance of the LD task. In children, DCD may reduce the strength of functional integration of postural activity with the demands of suprapostural visual tasks.
We prepare electrospun nanofibers (NFs) from a poly(N-vinylpyrrolidone)/manganese (II) acetate composite by electrospinning for application in supercapacitors. As-spun hybrid NFs are calcined at different temperatures to remove the polymer matrix, resulting in inorganic MnO x NFs of variable compositional ratios of Mn3O4 to Mn2O3. Interestingly, the sample of MnO x NFs that is calcined at 500 °C exhibits the highest electrochemical performance, reaching a high specific capacitance of 360.7 F g−1 at a current density of 1 A g−1. This remarkable performance is attributed to the unique three-dimensional morphology and the reduced interfacial resistance of the mixed-phase MnO x NFs within the matrix electrode and the electrolyte.
The direct observation of the microstructural evolution and state-of-charge (SOC) distribution in active materials is crucial to understand the lithiation/delithiation mechanisms during electrochemical cycling of lithium-ion batteries (LIBs). Owing to their high spatial resolutions and capability to map chemical states by combining other spectroscopic techniques, microscopic techniques including X-ray fluorescence (XRF) microscopy, Raman microscopy, transmission X-ray microscopy (TXM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) play significant roles in real time monitoring the dynamic changes in the LIB electrodes and materials. This paper reviews the recent progress of using in situ microscopic techniques to study LIB materials, including Si-, Sn-, Ge-, C- and metal oxides-based anode materials, and layered oxysulfide, metal fluorides, LiCoO2, LiNi0.8Co0.15Al0.05O2, LiMn2O4, LiFePO4 cathode materials.
We have studied the lithiation-induced amorphization of crystalline silicon by using first-principles calculations. Ab initio simulations show that crystalline silicon amorphizes at a ratio of 0.3 Li atoms per Si atom. Upon amorphization, the tetrahedral Si network suddenly collapses and the average number of Si atoms around Li significantly decreases from 4.6 to 2.6. We suggest the presence of ring structures, made of pure Si atoms and composite Li–Si atoms, as representative local structures of Li–Si amorphous alloy.
Thermal management is critically important to maintain the performance and prolong the lifetime of a lithium-ion (Li-ion) battery. In this paper, a two-dimensional and transient model has been developed for the thermal management of a 20-flat-plate-battery stack, followed by comprehensive numerical simulations to study the influences of ambient temperature, Reynolds number, and discharge rate on the temperature distribution in the stack with different cooling materials. The simulation results indicate that liquid cooling is generally more effective in reducing temperature compared to phase-change material, while the latter can lead to more homogeneous temperature distribution. Fast and deep discharge should be avoided, which generally yields high temperature beyond the acceptable range regardless of cooling materials. At low or even subzero ambient temperatures, air cooling is preferred over liquid cooling because heat needs to be retained rather than removed. Such difference becomes small when the ambient temperature increases to a mild level. The effects of Reynolds number are apparent in liquid cooling but negligible in air cooling. Choosing appropriate cooling material and strategy is particularly important in low ambient temperature and fast discharge cases. These findings improve the understanding of battery stack thermal behaviors and provide the general guidelines for thermal management system. The present model can also be used in developing control system to optimize battery stack thermal behaviors.
The paper analyzes data about recharge of electric cars in Rome during 2013 as a part of a national research project (P.R.I.M.E.). The electric vehicles were recharged through the public Enel Distribuzione recharging infrastructure. For each recharge, the initial and final time were registered together with the electricity absorbed from the grid. The total number of recharges was about 7700. The first step of the investigation is the statistical analysis of the distribution of recharges in daily time slots in order to analyze the recharge behavior of Italian drivers. For each day and for each time slot, literature data from the Italian national grid operator (Terna) were used to retrieve the energy mix used to produce electricity in that day and in that time slot. In the third step, electricity generation mixes were used to obtain emission factors for greenhouse (CO2) and pollutant emissions (CO, NO x , HC and particulate). Using information about the electric consumption of vehicles registered in Rome, the emission factors in g/km were obtained and compared with the limits set by European legislation for conventional (gasoline and diesel).
A typical dispersion of iron oxide nanoparticles in alkali electrolyte is limited to 20 wt% solids, above which it has a paste-like consistency (>370 cP), incompatible with flow applications. The formulation of stable electrochemically active colloids of nanoscale iron oxide (30–50 nm) with up to 70 wt% solids, low viscosity (<30 cP) with minimal shear dependence (±2 cP), excellent colloidal stability (>2 weeks at rest), and 55% enhancement in thermal conductivity is reported herein. A thin surface coating allows for good particle dispersion, which is shown to be crucial for these enhanced features. These suspensions of electrochemically active nanoparticles (nanoelectrofuels) can undergo electrochemical charge and discharge in fluidized format through particle–electrode impact events with potential for application in redox flow batteries. The surface coating is found to partially suppress electrochemical access to the nanoparticle in a fluidized format but has no detrimental effects on discharge capacity in the solid state. This approach is also shown to suppress a parasitic nanoparticle agglomeration process, which is otherwise dominant during electrochemical cycling of pristine iron oxide. A dissolution re-precipitation mechanism is proposed to offer insight into this auxiliary benefit. This study provides the first insight into the feasibility of adopting electrochemically active nanofluids as high energy density redox flow battery electrolytes.
The all-solid-state Li–In/Li4Ti5O12 cell using the 80Li2S·20P2S5 (mol%) solid electrolyte was assembled to investigate rate performances. It was difficult to obtain the stable performance at the charge current density of 3.8mAcm−2 in the all-solid-state cell. In order to improve the rate performance, the pulverized Li4Ti5O12 particles were applied to the all-solid-state cell, which retained the reversible capacity of about 90mAhg−1 at 3.8mAcm−2. The 70Li2S·27P2S5·3P2O5 glass–ceramic, which exhibits the higher lithium ion conductivity than the 80Li2S·20P2S5 solid electrolyte, was also used. The Li–In/70Li2S·27P2S5·3P2O5 glass–ceramic/pulverized Li4Ti5O12 cell was charged at a current density higher than 3.8mAcm−2 and showed the reversible capacity of about 30mAhg−1 even at 10mAcm−2 at room temperature.
The aging products of the electrolyte from a commercially available state-of-the-art 18650-type cell were investigated. During long term cycling a huge difference in their performance and lifetime at different temperatures was observed. By interpretation of a strong capacity fading of cells cycled at 20 °C compared to cells cycled at 45 °C a temperature depending aging mechanism was determined. To investigate the influence of the electrolyte on this fading, the electrolyte was extracted by supercritical fluid extraction (SFE) and then analyzed by gas chromatography (GC) with electron impact (EI) ionization and mass selective detection. To obtain more information with regard to the identification of unknown decomposition products further analysis with positive chemical ionization (PCI) and negative chemical ionization (NCI) was performed. 17 different volatile organic aging products were detected and identified. So far, seven of them were not yet known in literature and several formation pathways were postulated taking previously published literature into account.
In the present study, polyaniline nanofibers have been grown inside the interlayer galleries of montmorillonite clay to form effective hybrid nanofillers. The effect of nanofillers on the properties of ionic liquid based polymer electrolytes has been investigated by varying the nanofiller concentration systematically. The dispersion of the hybrid nanofillers effectively enhances the ionic conductivity, electrochemical stability and the thermal stability. Scaling of AC conductivity shows that ion concentration and ion diffusion length change with changing nanofiller concentration. The dispersion of nanofillers increases free volume of the electrolyte to facilitate the ion hopping that result in increased ionic conductivity. Highest room temperature ionic conductivity of 7.7×10−3 S cm−1 is achieved at 7.5wt. % of the nanofiller content. Electrochemical stability increases with increase in nanofiller concentration attaining a maximum value of 5.8V at 7.5wt. % of nanofillers concentration. The thermal stability is enhanced on the addition of nanofillers as they act as heat and mass transport barrier for volatile species.
As the development of smart electronics, self-powered sources have been attracting increasing attention. This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-stage energy conversion. Recent development of three dimensional photovoltaic fibers is glanced with special attention to structure design and materials of typical photovoltaic types (inorganic, organic, dye/quantum dot sensitized and perovskite solar cells). The application of carbon materials in fiber energy is focused as it is a hot topic recently. The hybrid energy systems based on fiber solar cells and fiber supercapacitors, fiber batteries and fiber nanogenerators are summarized together with hybrid energy textiles. This review provides a macroscopic view of novel energy fibers and will attract research interest in flexible/wearable fiber electronics and energy textiles.
Occupants of dwellings with grid-connected photovoltaic (PV) systems can often benefit financially from exporting electricity to the grid. When export prices are lower than import prices, however, occupants are incentivised to time-shift demand in order to avoid exports and reduce imports. To maximise this potential financial benefit, the addition of batteries to the PV system has been proposed to take advantage of the specific commercial opportunity presented to the occupant of trading exported power during the day for imported power during the evening. This paper therefore assesses the economic and environmental impact of the use of lead-acid batteries in grid-connected PV systems under current feed-in tariff arrangements in the UK. The development of a lead-acid battery model is described, which is used to simulate hypothetical power flows using measured data on domestic PV systems in the UK. The simulation results indicate that the net benefit of the battery is negative, even when considering an idealised lossless battery. When realistic energy losses and lifetimes are accounted for, the financial loss for the systems considered here can approach £1000/year. The environmental impact of the use and production of the lead-acid battery is also described, and also found to be negative, further strengthening the argument against the use of lead-acid batteries in domestic grid-connected PV systems.
Metallic lithium (Li) has been acclaimed as the most promising anode materials for lithium batteries due to its ultrahigh theoretical capacity of 3860 mA h g−1. Its practical application is impeded, however, due to the notorious problems related to dendrite growth caused by its uneven current density distribution and high Li nucleation overpotential. Here, we report a three-dimensional (3D) lithiophobic phase (Cu) and lithiophilic phase (Zn or Sn) composite architecture realized through a facile electrochemical co-deposition technology and its use as a scaffold for dendrite-free Li metal anode. It is found that the simultaneous formation of this lithiophobic-lithiophilic composite on Cu foam leads to ultrafine lithiophilic phase (20 nm) and reduced Li nucleation overpotential, as well as enhanced homogeneity, which enables a uniform electric field distribution during lithium plating/stripping, thus facilitating even and dendrite-free Li deposition. In the meanwhile, the lithiophobic component in the composite acts as a strong backbone, helping to maintain structural stability during lithium storage. Also, the as-prepared three-dimensional micro/nanoporous scaffold with large surface area can effectively reduce the local current density and suppress Li dendrite growth. The full cells with the composite architecture/Li as anode and LiFePO4 as cathode show promising electrochemical performance with over 80% capacity retention over 1600 cycles at 5 C. This work broadens the horizon of lithiophilic hosts for next-generation high-performance Li metal batteries.