batterydata/paper-abstracts huggingface dataset:
119Sn Mössbauer spectroscopy, X-ray diffraction and electrochemical experiments were carried out to characterize the reaction mechanism of lithium with spinel phases of the Cu2S–In2S3–SnS2 system. This analysis reveals an irreversible part of the mechanism linked to the reduction of the cations involving a spinel to rocksalt transformation followed by a structural breakdown, and a reversible part linked to the formation of lithium-metal alloys. The electrochemical investigation has shown interesting reversible capacities for these materials, and their possible use as anode materials in lithium-ion cells.
This study presents a nanostructured Sn/SnOx@Ti3C2 composite by in-situ growth of Sn/SnOx nanoparticles on the interlayer of 2D MXene (Ti3C2Tx) nanosheets through facile electrostatic attraction and liquid phase reduction. X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy results illustrate that Sn/SnOx nanoparticles are uniformly distributed into the MXene (Ti3C2Tx) interlayer, forming a sandwich-like nanostructured composite. MXene (Ti3C2Tx) nanosheets suppress Sn/SnOx nanoparticles’ volume expansion and agglomeration and accelerate the Li-ion and electron transition due to the distinguished confinement effect and excellent graphite-like layered structure. Furthermore, Sn/SnOx nanoparticles are embedded as pillars to enhance the longitudinal structural stability of MXene matrix by preventing the re-stacking of nanosheets during lithium insertion/extraction. The nanosized particles still reduce lithium migration path and increase active areas. Therefore, the Sn/SnOx@Ti3C2 composite maintains 594.2 mAh g−1 after 200 cycles with a capacity recovery after 100 cycles. The synergistic effect of Sn/SnOx on MXene facilitates Sn/SnOx@Ti3C2 nanostructures, thereby exhibiting excellent electrochemical properties for lithium-ion batteries.
Based on the different levels of solubility of radon gas in organic solvents and water, a bubbling system has been developed to transfer radon gas, dissolving naturally in water samples, to an organic solvent, i.e. olive oil, which is known to be a good solvent of radon gas. The system features the application of a fixed volume of bubbling air by introducing a fixed volume of water into a flask mounted above the system, to displace an identical volume of air from an air cylinder. Thus a gravitational flow of water is provided without the need for pumping. Then, the flushing air (radon-enriched air) is directed through a vial containing olive oil, to achieve deposition of the radon gas by another bubbling process. Following this, the vial (containing olive oil) is measured by direct use of gamma ray spectrometry, without the need of any chemical or physical processing of the samples. Using a standard solution of 226Ra/222Rn, a lowest measurable concentration (LMC) of radon in water samples of 9.4 Bq L−1 has been achieved (below the maximum contaminant level of 11 Bq L−1).
This article presents a shrinking core model for the discharge of porous lead particle at the negative electrode of a lead-acid battery by considering the reaction in a separate particle of the solid matrix. The model relates the shrinking unreacted lead core with the maximum amount of active material that can be reacted before termination of the discharge process due to poorly soluble low-conducting product. The developed model equations also incorporate the effect of double-layer capacitance and a dissolution–precipitation mechanism on the discharge process. The expressions for evaluating concentration and potential distributions as functions of time and distance are presented in three different models of a porous lead particle. For the simple case, equations are solved to achieve analytical expressions and where the coupled potential and concentration gradients with dissolution–precipitation mechanism are taken into account; the numerical method of lines is utilized to study the discharge behavior. The simulation outcomes are in good agreement when compared with the experimental data for discharge.
Personality factors have been associated with Alzheimer’s disease (AD) and dementia, but they have not been examined against markers of regional brain glucose metabolism (a primary measure of brain functioning) in older adults without clinically diagnosed cognitive impairment. The relationship between personality factors derived from the five-factor model and cerebral glucose metabolism determined using positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-
Coupling electroactive species with carbon supports to fabricate hybrid electrodes holds promise for high-performance supercapacitors. Nevertheless, the poor compatibility and weak bonding between carbon substrates and electroactive species remain a bottleneck to be tackled. Herein, we present a superhydrophilic “nanoglue” strategy for stabilizing NiCo-layered double hydroxide (NiCo-LDH) nanosheets on inert carbon cloth (CC) by employing a nitrogen-doped (N-doped) carbon layer as the structure/interface coupling bridge to make hybrids (denoted as CC–NC-LDH) for supercapacitors. Such a “nanoglue” on a CC substrate results in the formation of a superhydrophilic surface/interface, which is favorable for the robust and uniform growth of NiCo-LDH on the CC, and helps effectively tune the electronic structural states and results in a strong coupling interaction between the CC and NiCo-LDH nanosheets. Benefiting from these integrated merits, asymmetric supercapacitors fabricated with the CC–NC-LDH hybrids as the positive electrode and typical activated carbon as the negative electrode deliver a high energy density of 69.7 W h kg−1 at a power density of 0.8 kW kg−1, with an ultra-low average capacitance fade rate of ∼0.00065% per cycle within 20000 cycles at a current density of 10 A g−1. This superhydrophilic “nanoglue” strategy can also be extended to assemble other kinds of active species on different inert substrates, and holds the potential for creating efficient and robust electrode materials for energy-related devices.
This paper presents a hierarchical predictive control strategy to optimize both power utilization and oxygen control simultaneously for a hybrid proton exchange membrane fuel cell/ultracapacitor system. The control employs fuzzy clustering-based modeling, constrained model predictive control, and adaptive switching among multiple models. The strategy has three major advantages. First, by employing multiple piecewise linear models of the nonlinear system, we are able to use linear models in the model predictive control, which significantly simplifies implementation and can handle multiple constraints. Second, the control algorithm is able to perform global optimization for both the power allocation and oxygen control. As a result, we can achieve the optimization from the entire system viewpoint, and a good tradeoff between transient performance of the fuel cell and the ultracapacitor can be obtained. Third, models of the hybrid system are identified using real-world data from the hybrid fuel cell system, and models are updated online. Therefore, the modeling mismatch is minimized and high control accuracy is achieved. Study results demonstrate that the control strategy is able to appropriately split power between fuel cell and ultracapacitor, avoid oxygen starvation, and so enhance the transient performance and extend the operating life of the hybrid system.
The kinetics of oxygen and hydrogen gas recombination on the metal hydride electrode in a NiMH cell is investigate as function of gas pressure, temperature, cycling and a hydrophobic additive. Both oxygen and hydrogen gas recombination rates in the NiMH cells are found to be linearly proportional to the gas pressure, indicating that surface processes with a constant number of reaction sites could be the rate limiting step. The rate of oxygen gas recombination is, however, more than 10 times faster than that of hydrogen at the same pressure. As the temperature increases, both reaction rates increase very rapidly, even though the solubilities of the gases in the KOH electrolyte decrease with temperature. The activation energies for oxygen and hydrogen gas recombination are 32.6kJmol−1 and 27.0kJmol−1, respectively. The reactions rates also increase as the cells are cycled. This indicates, that the number of active sites increases, as the surface area increases, due to the continuously decrepitating of the alloy particles. The hydrogen gas absorption rate increases dramatically after a large number of cycles due the drying of the MH electrode. A hydrophobic PTFE additive in the MH electrode can significantly improve hydrogen absorption efficiency in NiMH cells.
A novel synthesis method of thin-film composite Sn/C anodes for lithium batteries is reported. Thin layers of graphitic carbon decorated with uniformly distributed Sn nanoparticles were synthesized from a solid organic precursor Sn(IV) tert-butoxide by a one-step microwave plasma chemical vapor deposition (MPCVD). The thin-film Sn/C electrodes were electrochemically tested in lithium half cells and produced a reversible capacity of 423 and 297mAhg−1 at C/25 and 5C discharge rates, respectively. A long-term cycling of the Sn/C nanocomposite anodes showed 40% capacity loss after 500 cycles at 1C rate.
Background This study assesses the benefits of an individualized therapy (RECOS program) compared with the more general cognitive remediation therapy (CRT). Methods 138 participants took part with 65 randomized to CRT and 73 to RECOS. In the RECOS group, participants were directed towards one of five training modules (verbal memory, visuo-spatial memory and attention, working memory, selective attention or reasoning) corresponding to their key cognitive concern whereas the CRT group received a standard program. The main outcome was the total score on BADS (Behavioural Assessment of Dysexecutive Syndrome) and the secondary outcomes were: cognition (executive functions; selective attention; visuospatial memory and attention; verbal memory; working memory) and clinical measures (symptoms; insight; neurocognitive complaints; self-esteem). All outcomes were assessed at baseline (T1), week 12 (posttherapy, T2), and follow-up (week 36, i.e., 6months posttherapy, T3). Results No difference was shown for the main outcome. A significant improvement was found for BADS' profile score for RECOS at T2 and T3, and for CRT at T3. Change in BADS in the RECOS and CRT arms were not significantly different between T1 and T2 (+0.86, p=0.108), or between T1 and T3 (+0.36, p=0.540). Significant improvements were found in several secondary outcomes including cognition (executive functions, selective attention, verbal memory, and visuospatial abilities) and clinician measures (symptoms and awareness to be hampered by cognitive deficits in everyday) in both treatment arms following treatment. Self-esteem improved only in RECOS arm at T3, and working memory improved only in CRT arm at T2 and T3, but there were no differences in changes between arms. Conclusions RECOS (specific remediation) and CRT (general remediation) globally showed similar efficacy in the present trial.
Progress always requires energy. Up today, the energy needs have been provided by combustion of fossil fuels and this has increased the air pollution and the emission of greenhouse gasses. Consequently, the greenhouse emission problem could represents a concrete opportunity to promote the high-efficiency design of conventional plants, but also a new approach to energy systems and the consequent dissemination of advanced technologies. One of the most promising energy conversion technology is the fuel cell because it is an electrochemical device in which the chemical energy is directly converted into electrical energy, with low environmental impact. In this paper the losses of the fuel cells has been analysed.
A simple strategy which combines the treatment of industrial wastewater with the preparation of electrode materials was proposed in this work. And the industrial wastewater is the only iron source for the material preparation. The preparation method in this work is facile, economical and environment-friendly which includes two simple steps of low-temperature aqueous solution and one-step calcination. Moreover two kinds of high performance Fe2O3 anode materials (α-/γ-Fe2O3 nano spheres, respectively) with isomerism can be obtained by simply adjusting calcination temperatures. Both of the α-Fe2O3 and γ-Fe2O3 nanospheres show good lithium storing reversibility when used as anode materials in LIBs. Furthermore the as-prepared α-Fe2O3 nano-electrode with lower electrochemical impedance exhibit a far better electrochemical performance (about 74.1% capacity retention (calculated based on the lithiation) from the 1st to 5th cycle) than the γ-one (only 39.0% capacity retention from the 1st to 5th cycle). The results here provide economical yet environment-friendly strategies for developing advanced anode material demanding both high energy and long lifespan for full-cell lithium battery.
Six low-viscosity ionic liquids based on trialkylimidazolium cation with one or two ether groups and TFSA− anion are used as new electrolytes for lithium battery, and compared with three typical trialkylimidazolium ILs without ether group. It is found that ether group in trialkylimidazolium cation can have an obvious effect on properties of electrolyte and performances of lithium battery. Introducing of ether group into trialkylimidazolium cation can be benefit for lithium redox behavior on Ni electrode, and affect passivation layer between IL electrolyte and lithium metal. Li/LiFePO4 cells using these ether-functionalized IL electrolytes without additive have good battery performance, and IM(2o1)1(2o2)-TFSA electrolyte owns better rate property.
This paper investigates the discrepancy between double-layer supercapacitor voltage and the maximum electrochemical window voltage in an alkaline electrolyte. The electrochemical window is determined by the potential difference between hydrogen evolution and oxygen evolution. As the specific capacitance of a negatively polarized carbon material may be different from its positively polarized counterpart, the hydrogen evolution and oxygen evolution in the electrode may not occur at the same time. To achieve the electrochemical window voltage, the two electrodes in a double-layer supercapacitor need to be balanced and have the same capacitance to ensure that oxygen and hydrogen are generated at the same time.
We present a facile and simple method for the large-scale synthesis of octahedral iron oxide nanocrystals (Fe3O4 ONCs) on the reduced graphene oxide nanosheets (rGO NSs). The Fe3O4-ONCs embedded on the rGO NSs surfaces (Fe3O4-ONCs@rGO hybrids) are synthesized by microwave assisted. The Fe3O4 nanoparticles (Fe3O4 NPs) decorated rGO NSs (Fe3O4-NPs@rGO hybrids) are also synthesized using same method for comparative studies in lithium ion storage. During the synthesis process, rGO NSs served as the structural platform to embed the positively charged Fe3O4-ONCs on the basis of the electrostatic assembly followed by the microwave reduction of rGO NSs. Compared to Fe3O4-NPs@rGO, Fe3O4-ONCs@rGO hybrids shows superior electrochemical performance, including better cycling stability and rate performances, which may be attributed to the embedded structure of the nano-size Fe3O4-ONCs in rGO NSs. The electrochemical performances of the hybrids material as anode for lithium storage are evaluated by cyclic voltammetry and constant current charging and discharging. The synthesized Fe3O4-ONCs@rGO hybrids exhibited high lithium storage capacity, outstanding cycling stability (540 mAh g−1 after 120 cycles at 100 mA g−1). This low-cost and fast synthesis strategy may be employed in other embedded structured hybrids design for high-performance lithium batteries.
To maintain price and exchange rate stability, many emerging market and developing countries (EMDCs) de facto peg their exchange rates, intervening in the foreign exchange markets, but without formally committing to a peg. But in doing so, are they foregoing important benefits in terms of lower inflation? We argue that the de jure commitment, by making exit more costly, imparts greater credibility, which better anchors inflationary expectations, thereby leading to lower inflation than de facto pegging alone. Our empirical analysis, based on a novel data set of IMF de jure and de facto exchange rate regime classifications for 146 EMDCs over 1980–2010, finds that inflation is indeed lower—especially in emerging markets—by some 4 percentage points when the central bank both de jure commits and de facto pegs the exchange rate than when it de facto pegs alone. Thus, analogous to inflation targeting, where the formal commitment to the framework is thought to help anchor inflationary expectations, the de jure commitment to the peg may also be important to reap the full price-stability benefits of pegs.
Herein, we describe a simple solid-state synthesis of zinc sulfide (ZnS) and its amorphous carbon–modified nanocomposite (ZnS/C) and examine their performance as high-capacity anode materials for rechargeable Li-ion batteries, probing lithiation/delithiation mechanisms by ex situ X-ray diffraction and extended X-ray absorption fine structure analyses. The ZnS converted into LiZn and Li2S during lithiation, being subsequently incompletely recombined into ZnS during delithiation and thus resulting in traces of Zn and S. Based on the above investigation of reaction mechanism, the ZnS/C electrode was electrochemically tested within a potential range of 0–2.0 V vs. Li+/Li and exhibited a high reversible capacity of 681 mAh g−1, excellent cycling stability (>150 cycles), and high rate capability.
Several commercial-grade hybrid-VRLA and AGM-VRLA cells and batteries have been assembled and tested under varying charge–discharge rates in a temperature range between 50 and −40°C. Impedance studies on hybrid-VRLA and AGM-VRLA cells have been conducted to reflect on their resistive and capacitive values. A linear relationship is found to exist between logarithmic state-of-charge values and ohmic impedance of batteries. In general, hybrid-VRLA cells and batteries perform better than their AGM-VRLA counterpart. A field-performance study conducted on AGM-VRLA and hybrid-VRLA batteries for solar-lighting application also suggests the latter to be superior.
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The use of a rechargeable Li metal anode is one of the most favored choices for next-generation high energy density lithium batteries. Unfortunately, the growth of lithium dendrites during recharging hinders the practical application of Li metal anodes. Herein, we report a new biomimetic ionogel electrolyte with ant-nest architecture by the confinement of an ionic liquid within a chemically modified SiO2 scaffold for promoting the dendrite-free stripping/plating of Li anodes. The biomimetic ant-nest architecture not only has high ionic conductivity, but can also effectively restrain the Li dendrite growth by the spontaneous formation of a particle-rich protective layer on the lithium electrode during charge/discharge cycling. The solid-state full cells with LiNi1/3Mn1/3Co1/3O2 exhibit a very high energy density of ca. 390 W h kg−1. The as-prepared Li/Li4Ti5O12 full cells present excellent cycling stability up to 3000 cycles with excellent Coulombic efficiencies of >99.8%. The present work opens a new route for the use of the biomimetic concept for designing a new ant-nest ionogel electrolyte for developing high energy density Li metal batteries with high stability.
In this study, the case of meeting a hotel's electrical energy demand with hybrid systems has been examined by using four different scenarios. The HOMER program is used for different analyses. In the first case, when the renewable energy resources are insufficient, electrical energy is purchased from grid and in the cases, in which the production is much more than the need, electricity is sold to the grid. In three other cases, the electric demand of the hotel is met by using renewable energy and the amount, which is more than the need, is sold to the grid. As a result, at the present circumstances two scenarios were determined feasible. When the grid is used only selling surplus electricity and the electricity need of the hotel are met by only renewables, battery groups and converters are needed. So, this causes an increase in investment costs. Therefore, these situations must be supported with adequate incentives, to make these systems become more eligible.
Within this work, we systematically investigate the influence of the amount of free carbon phase on the electrical conductivity and the lithium storage capability of silicon oxycarbide (SiOC) materials. A series of SiOC ceramics comprised of free carbon content ranging from 8 to 54wt.% is examined. The ability to reversibly host lithium ions is correlated with the elemental composition and the electrical conductivity. The materials with low carbon content up to ∼20wt.% reveal conductivities lower than 310−5 Sm−1 and initially high capacities of more than 1000mAhg−1, which fade rapidly with continuous cycling. For the samples with higher amounts of free carbon phase, higher electrical conductivities ranging from 0.07 to 2.2Sm−1 are measured. In comparison to the carbon-poor materials, the carbon-rich samples demonstrate enhanced accessibility of Li-ion storing sites with capacities of more than 500mAhg−1. Moreover, a linear dependence between a stable capacity after 60 cycles and free carbon content in the ceramic is found.
This paper proposes maximum photovoltaic power tracking (MPPT) for the photovoltaic (PV) array using the fractional-order incremental conductance method (FOICM). Since the PV array has low conversion efficiency, and the output power of PV array depends on the operation environments, such as various solar radiation, environment temperature, and weather conditions. Maximum charging power can be increased to a battery using a MPPT algorithm. The energy conversion of the absorbed solar light and cell temperature is directly transferred to the semiconductor, but electricity conduction has anomalous diffusion phenomena in inhomogeneous material. FOICM can provide a dynamic mathematical model to describe non-linear characteristics. The fractional-order incremental change as dynamic variable is used to adjust the PV array voltage toward the maximum power point. For a small-scale PV conversion system, the proposed method is validated by simulation with different operation environments. Compared with traditional methods, experimental results demonstrate the short tracking time and the practicality in MPPT of PV array.
Research on indicators related to the state of child well-being is a growing field that has experienced several changes over time. The growing supply of data on children, as well as the need to facilitate conclusions and to track trends, has led researchers to develop a number of child well-being indexes. This paper critically reviews the most recent and relevant child well-being indexes, i.e., the Index of Child and Youth Well-Being in the United States, the Child Well-being Index for the European Union, the Microdata Child Well-being Index, and the Deprivation Index. The study focuses primarily on the contributions and innovations the indexes have brought to the field, making a critical assessment of the methods used in the construction of the indexes and identifying their main limitations.