batterydata/paper-abstracts huggingface dataset:
A sensitivity analysis of a mathematical model of a lithium-sulfur (Li–S) battery was performed, focusing on the effects of the discharge current and the electronic conductivity of the cathode by investigating the response of the model to variations of these parameters over a wide range of values. The behavior of the model battery system with respect to the variations of each parameter is explained in detail. The nonlinear response of the model to the parameter variations is presented. In particular, the discharge current causes different patterns of the voltage plateaus. The importance of the electronic conductivity of the cathode is also discussed in detail. A minimum conductivity requirement to activate the cell was observed, beyond which no significant improvement of the capacity performance occurs. This report evaluates the electrochemical aspects of different experimental results particularly regarding discharge voltage plateaus, and moreover, demonstrates the limits of the model.
While remote sensing imagery is effective for quantifying land cover changes across large areas, its utility for directly assessing the response of animals to disturbance is limited. Soundscapes approaches—the recording and analysis of sounds in a landscape—could address this shortcoming.
Magnesium-air battery is a promising energy storage device because of its high theoretical voltage, high specific energy, low cost, and greater safety. Due to the passivation of Mg surface with Mg(OH)2 in alkaline electrolyte (pH >11) prevents further reaction of the anode, Mg-air battery typically works in pH-neutral aqueous electrolyte. However, developing electrocatalysts for pH-neutral oxygen reduction with high activity at low cost remains a significant challenge. Here, we report a mixed-phase mullite (SmMn2O5) electrocatalyst as an efficient substitute for Pt/C in pH-neutral oxygen reduction reaction (ORR). The mixed-phase mullite exhibits similar catalytic activity but superior stability to Pt/C in 1M NaCl solutions. Density functional theory simulations reveal that the catalytic activity is correlated to the strength of p-d hybridization between octahedral Mn and lattice O in the mullite structure, which results in a moderate bond strength between adsorbed O atoms and square-pyramidal Mn dimer sites. The presence of CeO2 phase also facilitates the adsorption and diffusion of oxygen atoms on mullite surface. Finally, the feasibility of utilizing mixed-phase mullite catalyst is demonstrated by fabricating Mg-air batteries to power a red light-emitting diode.
A simple urea-assisted, auto-combustion synthesis was used to fabricate pure Co3O4 nanoparticles and their nanocomposite with 10wt% reduced graphene nanosheets. Samples were annealed at 500°C for 5h under nitrogen atmosphere and their structures and morphologies were characterized by X-ray diffraction, field-emission scanning electron microscopy, field-emission transmission electron microscopy, Raman spectroscopy and BET surface area analysis. The process led to a nanocomposite containing small (25–50nm) Co3O4 nanoparticles deposited on the graphene nanosheets. CHN analysis determined the carbon content in pure Co3O4 nanoparticles and Co3O4/CoO/graphene nanocomposite and found to be very low such as 0.091% and 2.41% respectively. In addition, to know the precise amount of CoO in the designed nanocomposite sample, phase fraction Le Bail's technique was used and found to be 20±0.5%. Using the Co3O4/CoO/graphene nanocomposite as an anode in lithium ion battery led to a higher lithium storage capacity than using pure Co3O4 nanoparticles electrode. The Co3O4/CoO/graphene nanocomposite electrode delivered an initial charge capacity of 890.44mAhg−1 and Exhibit 90% of good capacity retention (801.31mAhg−1) after 30 cycles. While pure Co3O4 nanoparticles electrode (877.98mAhg−1) fades quickly, retains only 60% (523.94mAhg−1) after 30 cycles. The improved electrochemical performance of nanocomposite was attributed to higher electron and Li+ ion conductivity and the larger surface area and mechanical flexibility afforded by the graphene nanosheets. At high current densities, both electrodes showed comparable reversible capacities, demonstrating the suitability of the present synthetic technique.
The aim of this work is the development of an optimization model in order to minimize the cost of Leaf Community microgrid. This cost is a sum of energy cost and the maintenance cost of the energy storage system (ESS). The developed objective function is constrained and the problem here is solved by using the method of genetic algorithms at Matlab. The genetic algorithm decides about the transportation of the energy from or to the ESS and it calculates an optimum cost. The optimization time horizon is 24 h ahead, thus the prediction of energy production and consumption was necessary. This was achieved by using neural networks. In order to verify the performance of the developed model, some scenarios were tested. This study concludes that a management of a microgrid can achieve energy and money savings.
For the possible application in high safety lithium ion batteries, nano-particle decorated poly(methyl methacrylate-acrylonitrile-ethyl acrylate) (P(MMA-AN-EA)) based gel polymer electrolyte (GPE) using 1-ethyl-3-methylimidazolium bis(trifluoromethanesolfonyl) imide (EMITFSI) ionic liquid as plasticizer was developed in this paper for the first time. Characterization of thermal stability indicated that the MS5 (SiO2: Al2O3 = 5:5 in weight) membrane presented better property of anti-thermal shrinkage, which in turn exhibited the excellent flame retardation performance for the corresponding GPE when incorporated with ionic liquid. The developed MS5 membrane had the strongest fracture strength of 160 MPa, much higher than that of polyethylene (PE) separator (138 MPa). Electrochemical analysis suggested that the GPE exhibited the enhanced ionic conductivity of 3.2 × 10−3 S cm−1 at ambient temperature, caused by its better porous structure with the highest porosity of 70%. The temperature dependence of ionic conductivity followed Vogel-Tamman-Fulcher (VTF) behavior. Oxidative potential of MS5 based GPE was significantly improved from 4.7 V (vs. Li+/Li) (PE saturated with ionic liquid) to 5.7 V. Theoretical calculation results showed that the stronger interaction between lithium ions and TFSI− anions was responsible for the better compatibility of GPE with the electrodes. Thus, MS5 based GPE exhibited excellent cyclic stability, which kept 95.1% capacity retention after 100 cycles under 0.2C rate in LiFePO4/GPE/Li type coin cell at room temperature, while retained 88.4% of initial discharge capacity at high temperature of 55 °C. Due to the enhanced transference number of lithium ion of the GPE, LiFePO4 cathode in LiFePO4/GPE/Li coin cell also presented superior rate performance.
Effect of 100keV proton radiation on the structure and tensile properties of PTFE film was investigated. The change in structure before and after proton radiation was mainly evaluated by means of differential scanning calorimetry. The experimental results show that under radiation of 100keV protons for the fluence less than 7×1015 p/cm2, the DSC characteristics including the phase enthalpy of transformations at room temperature ΔH rt1 and ΔH rt2, the melting enthalpy ΔH m1 and ΔH m2, the crystallization exothermal enthalpy ΔH c, and Tg II were decreased, while the melting temperature was increased a little with the fluence increase. The change in crystallization enthalpy ΔH c indicated the increase of molecular weight of the PTFE film, but for 150keV when the fluence exceeded the fluence of 1016/cm2, the molecular weight decreased gradually. With increasing proton fluence, the thermal gravity loss was decreased, while the initial decomposition temperature increased, demonstrating that crosslinking of molecular chains occurred. With the increase of the proton fluence, for proton with energy less than 150keV, the tensile fracture strength increased at first, but when the fluence exceeded 1016/cm2, the tensile fracture strength showed a decreasing trend. While for the proton of 170keV, the tensile fracture strength σ f increased abruptly at the fluence of 2×1013/cm2, with the fluence increasing further, the tensile fracture strength σ f decreased gradually. The change of tensile properties could be related with the competition of branching crosslinking and the scission degradation.
HIV-associated neurocognitive disorders (HAND) are one of major comorbidities in patients with HIV-1 infection. There are currently no standardized tests for screening HAND in such patients. The sensitivity of the cognitive function tests routinely used in clinical practice, such as the Mini-Mental State Examination and the Revised Hasegawa's Dementia Scale, is inadequate to rule out HAND, even in patients with clear abnormal behavior. We report a 41-year-old man with HIV-associated dementia, the most severe form of HAND, in whom the simplified methods did not show abnormal results, and a comprehensive battery of neuropsychological tests which covering several cognitive domains was needed to detect cognitive impairment.
Identifying novel functional materials either manually or by using algorithm-based analytics is a complex and resource demanding task. Here, the authors present an autonomous search system which combines Monte Carlo tree search and molecular dynamic simulations in order to successfully identify organic molecules based on their viscosity for use as industrial lubricants.
We analyze the impact of different electric vehicle (EV) charging strategies on the German power system in the year 2030 by explicitly including neighboring countries. A novel parametrization approach dealing with the weekday dependent variations of EV demand is introduced. Investigating a broad interval of CO2 prices yields robustness against varying merit order curves. The underlying nonlinear relationship leads to qualitatively different impacts of EVs on power plant dispatch at different CO2 prices. Furthermore, we find that curtailment of renewable energy sources is reduced independently of the charging strategy. Concerning system cost and emissions, the charging strategy vehicle-to-grid proves to be most beneficial. We show that at low CO2 prices, a production increase of emission intense technologies, such as lignite power plants is overcompensated by several other system components.
Volumetric capacitance is an important parameter for device applications. By simply compressing activated microwave-expanded graphite oxide (a-MEGO)-based electrode material, a volumetric capacitance of up to 110F/cm3 (3.5V maximum voltage) was achieved, when measured in a two-electrode cell supercapacitor configuration in an organic electrolyte. Nitrogen adsorption showed that the mesopores of a-MEGO (∼4nm) collapsed due to the compression, and more micropores (1–2nm) contributed to the energy storage in the compressed electrodes compared to uncompressed electrodes. This change in pore structure resulted in a higher effective series resistance and thus reduced power density in the compressed samples.
Objectives (1) To explore moderators of the effects of home-based exercise on reductions in physical and mental fatigue scores in postpartum depressed women and (2) to explore mediators of the intervention on changes in physical fatigue. Method Eighty-eight women in the postpartum period (4–38 weeks) obtaining a score ≥10 on the Edinburgh Postnatal Depression Scale were randomly assigned to a 12-week individualized home-based exercise intervention (n=46) or a no-treatment control group (n=42). The present analyses include the 35 women who adhered to the intervention and the no-treatment control group. Participants completed a cardiovascular fitness test, and a battery of questionnaires assessing the outcomes (Physical and Mental Fatigue) as well as potential moderators and mediators at baseline and posttreatment. Results Hierarchical linear regressions evaluating moderators of changes in mental fatigue with exercise showed that the intervention was effective for women entering the study later in the postpartum period (P=.001) and women with higher depression scores (P=.014). Reductions in physical fatigue with exercise were partially mediated by reductions in perceived stress and increased exercise-related energy expenditure. Conclusion Identification of moderators allows for the tailoring of exercise interventions to particular subgroups of women that are most likely to benefit. The identified mediators may be enhanced and directly tested in future trials.
This paper reviews the history of fuel cells. Its follows the path from the invention of the fuel cell up to present days. Fuel cell types as well as their advantages, disadvantages and principal applications nowadays are explained. History teaches once again that devices perceived by the public as recent inventions, are actually the product of many years (almost two centuries in this case) of arduous research.
Rechargeable sodium metal batteries have attracted attention as promising power sources over the last several years, because they are a lower cost option for large scale energy storage from the electric grid. However, among the main problems of Na-metal batteries, the formation of nonuniform solid electrolyte interfaces and the dendritic growth of sodium metal are particularly challenging. Here, we report on highly-concentrated sodium electrolytes based on liquid ammonia in which a large amount of sodium salt has been dissolved. These electrolytes can be generally described as NaY·xNH3, where Y is the anion (I−, BF4− or BH4−) and x indicates the molar ratio of ammonia to sodium salt. These electrolytes are characterized by their excellent properties such as low flammability and high specific conductivity. Most importantly, they support nondendritic and highly reversible plating–stripping of sodium, paving the way for the development of sodium metal anodes at room temperature. In addition, sodium deposition can be performed on copper as a substrate with a high coulombic efficiency and deposit stability.
Solar Photovoltaic system comprises of photovoltaic (PV) array, converter, inverter and battery storage unit of appropriate capacity to serve the load demand in reliable, efficient and economically feasible manner. The proper selection of technology and size of these components is essential for stable and efficient operation of PV system. Therefore, a number of modeling equations and methodologies for designing a PV system based on application have been developed in order to ensure the optimum performance of the PV system. In this paper, a comprehensive designing process of solar photovoltaic water pumping system, standalone PV system and grid connected PV system is presented. The modeling of PV modules, cell temperature, water pumping system and battery state of charge is tabularized so as to facilitate their utilization for proposing a PV system based on the techno-economic variables and environmental parameters. The financial and reliability parameters for techno-economic size optimization of PV system are also identified and different optimization techniques have been discussed. A state of art literature survey has been presented which is useful in designing and installation of solar PV systems for standalone as well as grid connected power supply.
Potassium-ion batteries (KIBs) are regarded as potentially promising large-scale energy storage (EES) systems due to the close redox potential to lithium, the rich reserve and low cost of potassium resources. Nevertheless, the larger ionic radius of K-ion makes cathode materials for KIBs be a difficult issue. Herein, we construct Mn-based layered oxide (K0.32MnO2) microsphere, self-assembled by ultrathin nanosheets, as potential cathode electrode for nonaqueous KIBs, which delivers a reversible discharge capacity of 95.1 mAh·g−1 at 10 mA g−1. It is demonstrated that K0.32MnO2 undergoes a simple solid solution reaction mechanism for K-ions deintercalation/intercalation during the initial charge-discharge process, which is not like complex multiple processes accompanied by phase transition for Mn-based layered oxide particles. Ex situ measurements reveal that K0.32MnO2 nanosheets can provide outstanding morphology and structure stability, as well as fast electrochemical kinetics upon cycling, thus high rate capacity, improved cycling lifetime and voltage stability at low and high rates can be obtained. We also verify the practical feasibility of K-ion full cell with commercial super P carbon black anode. This novel work illuminates the electrochemical mechanism for K-ions storage in depth, which may push the study on layered oxide cathodes and accelerate the development of KIBs.
A high penetration of variable renewable energy sources in an electricity generation mix leads to strong constraints on the whole system to ensure a continuous balance between electricity production and consumption. We have developed a new numerical methodology to quantify the relevance of several electricity storage devices that would provide the required flexibility. First of all, through a signal analysis (wavelet decomposition) of photovoltaic power (PV), wind power and load time series, we study and characterize the intermittency at different time scales. Then, each storage technology is evaluated for each time scale from an energy return on investment (EROI) standpoint. They are also compared with the possibility of curtailing excess electricity instead of storing it. The relevance of a given technology especially depends on its efficiency and embodied energy. For instance, we show that batteries are not appropriate for long term storage because of their high embodied energy. However, they are a good choice for short term applications with high cycle requirements because of their efficiency. We characterize the relevance of storage devices, their sensitivity to the production mix and to technological characteristics. We point out that satisfying the energy demand of exceptional events only with storage devices requires an over-sizing of the whole system. It underlines the complementarity of energy storage with dispatchable electricity sources. We eventually show that seasonal electricity storage is particularly difficult to ensure with a good energy return on investment.
Electrochemical and thermal studies were performed to investigate: a) a fluorinated electrolyte (FE) containing fluoroethylene carbonate (FEC) as the co-solvent, and b) a non-fluorinated electrolyte (NFE) containing ethylene carbonate (EC) as the co-solvent, for lithium ion cells. Electrochemical impedance spectroscopy (EIS) measurements were performed on both electrolytes to estimate ionic conductivity. Cyclic voltammetry was employed to probe the effect of co-solvent fluorination on electrolyte oxidative stability. Cycling, rate capability, and EIS tests were performed on lithium ion coin cells (of 2032 size) to investigate the effect of the FEC co-solvent on the electrochemical performance of (LiNi0.8Co0.15Al0.015O2) at the cathode. Differential scanning calorimetry (DSC) studies were performed to quantify the exothermic heat associated with delithiation of the (LiNi0.8Co0.15Al0.015O2) cathode in the presence of electrolytes containing FEC and EC as the co-solvent respectively. A remarkable improvement in the thermal stability of (Li0.36Ni0.8Co0.15Al0.015O2) was observed when FEC was used as the co-solvent. Besides the upward shift of the onset temperature by 24°C, the exothermic heat was also reduced by 15%. Cells prepared with FE showed good electrochemical performance at low rates and moderate performance at high rates when compared to cells prepared with NFE.
Layered-structured ternary oxide Na0.67[Ni0.4Co0.2Mn0.4]O2 is synthesized as cathode material for sodium-ion batteries. Using a liquid nitrogen quenching process during the synthesis procedure, a Na0.67[Ni0.4Co0.2Mn0.4]O2 powder with a mixed P2-O3 structure is obtained, and then characterized. The Na//Na0.67[Ni0.4Co0.2Mn0.4]O2 cell delivers a reversible capacity of 167mAh g−1 and exhibits excellent cycling and rate performances without abnormal initial coulombic efficiency.
In our continued efforts for improving the performance of zinc anodes for a Zn/air battery, we now report the preparation of three alloys and improved performances of anodes made up with these alloys. The alloys contained zinc, nickel, and indium with different weight percentages and were calcined at two different temperatures. Out of the six alloys, the alloy which has a composition of zinc 90%, nickel 7.5% and Indium 2.5% and fired at 500°C is found to be the best. In the case of the hydrogen evolution reaction, this alloy had its potential shifted to a more negative potential. As far as the cyclic voltammograms were concerned, the difference between the anodic and cathodic part was minimal when compared with other alloys. Surprisingly, this alloy had reversibility even after 100 cycles of the cyclic voltammogram. This is a clear indication that dendrite formation was reduced to a considerable extent. Images taken with a scanning electron microscope also indicated reduced dendrite formation.
A micro-model for the calculation of the area specific resistance ASRcat of a porous mixed ionic electronic conducting (MIEC) cathode, which resolves the microstructure, has been presented in Part I of this article. Four processes are considered relevant for a parametric study of this solid oxide fuel cell (SOFC) model. These comprise a charge transfer process between the electrode and the electrolyte and three noncharge transfer processes in the porous electrode: (i) gas diffusion, (ii) bulk diffusion and (iii) surface reaction. In Part II we present a systematic parameter sensitivity analysis of the four parameters that describe these processes. We define an index called sensitivity factor that allows the quantitative determination of the importance of the different processes for a reconstructed 3D microstructure.
Electrochemical Impedance Spectroscopy (EIS) is a sophisticated analyzing tool in battery research. Though, there are still phenomena subject to speculation. As an example, for a long time the formation of the so-called Solid Electrolyte Interphase (SEI) has been made responsible for inductive loop formation in impedance spectra. In our opinion, there are, however, no satisfying evidences supporting this attempt to explain the occurrence of inductive loops. The present study is, thus, aimed at answering the question whether other origins such as cell design ought to be considered to reveal the electrical sources for this phenomenon. Therefore, two commonly used anode materials for lithium-ion batteries were investigated with respect to their tendency to the formation of SEIs. Besides the influence of the SEI on the overall impedance response, also the impact of the cell design on electrical response was investigated. We identified four different sources of (i) inductive and (ii) negative capacitance loop formation: springs, reference electrodes, drift, and corrosion. In conclusion, any interrelationship between inductive loops and SEI formation could be ruled out. This finding disproves an earlier, commonly known attempt that traced the presence of inductive loops back to the formation of passivating surface layers because of electrolyte decomposition.