batterydata/paper-abstracts huggingface dataset:
High-capacity anodes hold great promise for the next-generation lithium-ion batteries. However, such electrodes are known to suffer from mechanical degradation during battery cycling. One important failure mode commonly observed in thin-film electrodes is film delamination from the underneath current collector. Here, by accounting for the nonlinear coupling between the chemical and mechanical fields, we derive the stress intensity and solute segregation factors close to the edge of a thin elastic film which is bonded to the surface of a thick elastic substrate. The film is considered in chemical equilibrium with an external mass reservoir. While in the limit of extremely weak coupling, our formulation reduces to the classical delamination theory, the results indicate that the chemo-mechanical coupling leads to magnification of the stress intensity factor and solute segregation near the film edge. The effect of coupling on the solute and stress distribution in the film is discussed. Further, an analytical expression is derived for the edge stress intensity factor in the limit of extremely strong chemo-mechanical coupling, based on which a modified critical film thickness to avoid edge delamination is proposed. Potential implication of the results for fatigue delamination growth is also discussed.
A recent concept called the fragmentation-energy fan has been used to analyze drop weight testing (DWT) data and to obtain both the mathematical form of the breakage index equation, i.e., t10 versus impact energy and the parameter values needed for making an actual prediction with it. The fan is visualized by plotting the progeny size corresponding to a set of percent passing values versus scaled drop energy in log–log scale and fitting straight, i.e., linear fan lines with a common focal point to these data. The fan behavior lies inherent in the fact that the DWT sieving data closely follow the Swebrec distribution. A mathematical expression for t10 in closed form follows directly from a functional inversion, and this expression differs from the forms it has been given by the JKMRC. In most cases five fan lines suffice to provide a very accurate t10 equation. When applied to a suite of eight rocks, ores mostly, the coefficient of determination R2
Laboratory drop weight testing (DWT) of lumps of rock is a way to characterize the breakage properties of ore and rock so that design and modeling of comminution circuits can be made with confidence (Napier-Munn et al. 1996). The DWT yields initially sieving curves for the progeny generated and their dependence on the drop energies Ecs
The JKMRC has been leading in the development of the DWT (Shi 2016), and one of the most extensive available data sets on laboratory drop weight testing (DWT) of lumps of rock, mostly ores, is found in the thesis of Banini (2002) from the JKMRC.
Storage and Demand Side Management (DSM) are key in integrating renewable energy into community energy systems. There are many modelling tools which support design of such systems. In order to select an appropriate tool it is essential to understand tool capabilities and assess how these match requirements for a specific situation. The aim of this paper is to provide a process to be used to make such a selection consisting of: (i) a tool capability categorisation, (ii) a stepwise tool selection process. Capabilities of 13 tools (screened from 51) for community scale were categorised covering: input data characteristics; supply technologies; design optimisation; available outputs; controls and DSM; storage; and practical considerations. A stepwise selection process is defined, adapted from software engineering, in which tools are scored based on ‘essential’, ‘desirable’, or ‘not applicable’ technical capabilities for the specific situation. Tools without essential capabilities are eliminated. Technical scores and practical considerations are then used to select the tool. The process is demonstrated for a simple case study. The future applicability of the selection process is discussed. Findings from the capability categorisation process are highlighted including gaps to be addressed and future trends in modelling of such systems.
The cycling performances of the cell with poly(ethylene oxide) (PEO)-based composite polymer electrolyte using BaTiO3, TiO2, and Al2O3 as filler, lithium metal anode, and LiNi0.8Co0.2O2 cathode at 80°C have been examined. The cycling performance depended on the filler in PEO-Li(CF3SO2)2N electrolyte. The best result was obtained in the electrolyte with the BaTiO3filler. The good cycling performance in the cell of Li/PEO19Li(CF3SO2)2N-BaTiO3/LiNi0.8Co0.2O2 was explained by the improved interfacial stability between the electrolyte and the electrode. The cycling performance of PEO-based polymer electrolyte cell was influenced by the charge and discharge cut-off voltage. The electrochemical window of PEO19Li(CF3SO2)2N-BaTiO3 composite electrolyte was estimated to be <4.0V.
Standard mean imputation for missing values in the Western Ontario and Mc Master (WOMAC) Osteoarthritis Index limits the use of collected data and may lead to bias. Probability model-based imputation methods overcome such limitations but were never before applied to the WOMAC. In this study, we compare imputation results for the Expectation Maximization method (EM) and the mean imputation method for WOMAC in a cohort of total hip replacement patients.
CuO/C microspheres are prepared by calcining CuCl2/resorcinol-formaldehyde (RF) gel in argon atmosphere followed by a subsequent oxidation process using H2O2 solution. The microstructure and morphology of materials are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). Carbon microspheres have an average diameter of about 2μm, and CuO particles with the sizes of 50–200nm disperse in these microspheres. The electrochemical properties of CuO/C microspheres as anode materials for lithium ion batteries are investigated by galvanostatic discharge–charge and cyclic voltammetry (CV) tests. The results show that CuO/C microspheres deliver discharge and charge capacities of 470 and 440mAhg−1 after 50 cycles, and they also exhibit better rate capability than that of pure CuO. It is believed that the carbon microspheres play an important role in their electrochemical properties.
Limbic system-associated membrane protein (LSAMP) is a neural cell adhesion molecule involved in neurite formation and outgrowth. The purpose of the present study was to characterize the distribution of alternatively transcribed Lsamp isoforms in the mouse brain and its implications on the regulation of behavior. Limbic system-associated membrane protein 1b transcript was visualized by using a mouse strain expressing beta-galactosidase under the control of Lsamp 1b promoter. The distribution of Lsamp 1a transcript and summarized expression of the Lsamp transcripts was investigated by non-radioactive in situ RNA hybridization analysis. Cross-validation was performed by using radioactive in situ hybridization with oligonucleotide probes. Quantitative RT-PCR was used to study correlations between the expression of Lsamp isoforms and behavioral parameters. The expression pattern of two promoters differs remarkably from the developmental initiation at embryonic day 12.5. Limbic system-associated membrane protein 1a promoter is active in “classic” limbic structures where the hippocampus and amygdaloid area display the highest expression. Promoter 1b is mostly active in the thalamic sensory nuclei and cortical sensory areas, but also in areas that regulate stress and arousal. Higher levels of Lsamp 1a transcript had significant correlations with all of the measures indicating higher trait anxiety in the elevated plus-maze test. Limbic system-associated membrane protein transcript levels in the hippocampus and ventral striatum correlated with behavioral parameters in the social interaction test. The data are in line with decreased anxiety and alterations in social behavior in Lsamp-deficient mice. We propose that Lsamp is involved in emotional and social operating systems by complex regulation of two alternative promoters.
Insights about the failure mechanism of negative electrodes based on NaAlH4 for lithium batteries are here discussed based on electrochemical-pressure measurements, galvanostatic cycling, infrared spectroscopy and impedance spectroscopy. The accumulation of irreversible capacity in the first cycle and the capacity fading have multiple origins. Besides the mechanical instability due to volume expansions/contractions upon lithium incorporation/de-incorporation, two additional reasons for electrode failure have been disclosed, both related to active material consumption: (1) the irreversible oxidation upon charge of the alanates that leads to H2 release, and (2) the spontaneous chemical reaction of the electrode active material with the electrolyte due to an unstable solid electrolyte interface. Both problems can be tackled by limiting the anodic voltage cutoffs in lithium cells and by the use of innovative electrolytes based on mixture of an ionic liquid and the standard carbonate-based solvent blend. The use of both strategies allowed us to assemble and demonstrate for few cycles the operation of a full Li-ion cell with a negative electrode based on NaAlH4 and a LiFePO4 positive electrode.
Fabricating of high performance electrodes by a sustainable and cost effective method is essential to the development of vanadium redox flow batteries (VRFBs). In this work, an effective strategy is proposed to deposit carbon nanoparticles on graphite felts by hydrothermal carbonization method. This in-situ method minimizes the drop off and aggregation of carbon nanoparticles during electrochemical testing. Such integration of felts and hydrothermal carbons (HTC) produces a new electrode that combines the outstanding electrical conductivity of felts with the effective redox active sites provided by the HTC coating layer. The presence of the amorphous carbon layers on the felts is found to be able to promote the mass/charge transfer, and create oxygenated/nitrogenated active sites and hence enhances wettability. Consequently, the most optimized electrode based on a rational approach delivers an impressive electrochemical performance toward VRFBs in wide range of current densities from 200 to 500 mA cm−2. The voltage efficiency (VE) of GFs-HTC is much higher than the VEs of the pristine GFs, especially at high current densities. It exhibits a 4.18 times increase in discharge capacity over the pristine graphite felt respectively, at a high current density of 400 mA cm−2. The enhanced performance is attributed to the abundant active sites from amorphous hydrothermal carbon, which facilitates the fast electrochemical kinetics of vanadium redox reactions. This work evidences that the glucose-derived hydrothermal carbons as energy storage booster hold great promise in practical VRFBs application.
The penetration of electric vehicles becomes a catalyst for the sustainability of Smart Cities. However, unregulated battery charging remains a challenge causing high energy costs, power peaks or even blackouts. This paper studies this challenge from a socio-technical perspective: social dynamics such as the participation in demand-response programs, the discomfort experienced by alternative suggested vehicle usage times and even the fairness in terms of how equally discomfort is experienced among the population are highly intertwined with Smart Grid reliability. To address challenges of such a socio-technical nature, this paper introduces a fully decentralized and participatory learning mechanism for privacy-preserving coordinated charging control of electric vehicles that regulates three Smart Grid socio-technical aspects: (i) reliability, (ii) discomfort and (iii) fairness. In contrast to related work, a novel autonomous software agent exclusively uses local knowledge to generate energy demand plans for its vehicle that encode different battery charging regimes. Agents interact to learn and make collective decisions of which plan to execute so that power peaks and energy cost are reduced system-wide. Evaluation with real-world data confirms the improvement of drivers’ comfort and fairness using the proposed planning method, while this improvement is assessed in terms of reliability and cost reduction under a varying number of participating vehicles. These findings have a significant relevance and impact for power utilities and system operator on designing more reliable and socially responsible Smart Grids with high penetration of electric vehicles.
Nanosized LiCrO2·Li2MnO3 composite powders are prepared by a new concept spray pyrolysis. The precursor and post-treated powders have a Li2CrO4 impurity introduced by the partial oxidation of LiCrO2. The powders have a pure layered structure corresponding to the LiCrO2·Li2MnO3 composite after Li2CrO4 is removed by washing with distilled water. The real composition of the washed cathode powders is Li1.18Cr0.404Mn0.477O2. The aggregated post-treated powders are converted into nanosized powders after washing with distilled water; milling is not required for this conversion. The mean size of the nanosized LiCrO2·Li2MnO3 powders is 48nm. The LiCrO2·Li2MnO3 cathode sample post-treated at 750°C has initial charge and discharge capacities of 272 and 233mAhg−1 at a constant current density of 18mAg−1, respectively. The discharge capacity of the cathode sample post-treated at 750°C decreases from 233 to 222mAhg−1 by the 44th cycle, in which the capacity retention is 95%.
Size optimization of solar array and battery in a standalone photovoltaic (SPV) system is investigated. Based on the energy efficiency model, the loss of power supply probability (LPSP) of the SPV system is calculated for different size combinations of solar array and battery. For the desired LPSP at the given load demand, the optimal size combination is obtained at the minimum system cost. One case study is given to show the application of the method in Malaysian weather conditions.
Li-ion storage electrodes are manufactured through the conventional cast process involving the use of a toxic solvent (n-methyl-2- pyrrolidone, NMP) and the binder polyvinylidene fluoride (PVDF). This process can be problematic for nanosized materials as they form viscous suspensions that prevent the formation of uniformly dense coatings. Additionally, the NMP solvent is very hazardous. Herein lies the viability of using electrophoretic deposition (EPD) as an alternative manufacturing process that would both eliminate the need for a toxic solvent and improve electrode properties is presented. In particular, it is shown that styrene- butadiene rubber (SBR) enables the assembly of carbon-coated LTO and carbon nanoparticles into bridged hetero-aggregates that render themselves to fast growth of adherent highly performing LIB electrodes. The electrodes are built by suspending C-coated LTO, carbon, and SBR at 80/10/10 wt% ratio in a medium consisting of 90/10 vol% acetonitrile and water, performing 3–5 stages of 15-s constant current deposition cycles followed by pressing at 4 MPa and drying in a vacuum oven. Raman spectroscopy, thermogravimetric analysis (TGA), and energy-dispersive X-ray spectroscopy (EDS) with SEM were performed to examine carbon/LTO composite film homogeneity and compared to conventional PVDF-based electrodes. More importantly, photoemission electron microscopy (PEEM) and X-ray absorption near edge structure (XANES) were used to probe the presence/distribution of the SBR binder in the coating. The EPD-based electrode exhibits superior rate capability when compared to the PVDF-based electrodes. The conductivity, as shown by EIS, of the pressed EPD electrodes was 15 times higher than that of the pressed PVDF electrodes demonstrating the superiority of EPD in fabricating highly conductive electrodes for high-power LIB application.
This paper demonstrates a low temperature solvothermal method for the synthesis of a layered spheric TiO2. The crystal structure and morphology of the material were characterized by using X-ray diffraction (XRD) and scanning electron miscopy (SEM). Electrochemical performances of the TiO2 when used as anode material in lithium ion batteries were investigated by galvanostatic charge/discharge and cyclic voltammetry experiments. A discharge capacity of 179mAhg−1 was obtained in the potential range between 3.0 and 1.5V. No significant capacity decay was observed in the successive 30 cycles showing satisfactory cycling performance of the electrode.
Flowable suspensions that conduct both electrons and ions can enable the use of energy-dense electroactive species in flow batteries [M. Duduta et al., Adv. Energy Mater., 1, 511 (2011); Z. Li et al., Phys. Chem. Chem. Phys., 15, 15,833 (2013); F. Fan et al., Nano Lett., 14, 2210 (2014)]. In comparison with conventional flow batteries where electrochemical reactions are confined to a fixed current-collector region, electronically conductive flow electrodes permit electrochemical reactions to extend outside of the physical confines of the stack. We have measured and modeled how mixed-conduction enables an electroactive zone (EAZ, in which electrochemical reactions occur) that is of greater spatial extent than current collectors, the extension being termed side zone, SZ. Electrochemical reactions in SZs can reduce coulombic and energetic efficiency. Here we show that for realistic suspension properties and operating conditions, the added inefficiency is small in practice, and can be further mitigated by using appropriate operating conditions and/or materials choices. For the specific example of a non-aqueous Li4Ti5O12 suspension, we show that EAZ extension contributes less than 1% additional efficiency loss at C/10 rates for current collectors greater than 20mm long.
In this research, we studied the first cycle characteristics of Li[Ni1/3Co1/3Mn1/3]O2 charged up to 4.7V. Properties, such as valence state of the transition metals and crystallographic features, were analyzed by X-ray absorption spectroscopy and X-ray and neutron diffractions. Especially, two plateaus observed around 3.75 and 4.54V were investigated by ex situ X-ray absorption spectroscopy. XANES studies showed that the oxidation states of transition metals in Li[Ni1/3Co1/3Mn1/3]O2 are mostly Ni2+, Co3+ and Mn4+. Based on neutron diffraction Rietveld analysis, there is about 6% of all nickel divalent (Ni2+) ions mixed with lithium ions (cation mixing). Meanwhile, it was found that the oxidation reaction of Ni2+/Ni4+ is related to the lower plateau around 3.75V, but that of Co3+/Co4+ seems to occur entire range of x in Li1−x [Ni1/3Co1/3Mn1/3]O2. Small volume change during cycling was attributed to the opposite variation of lattice parameter “c” and “a” with charging–discharging.
LiCo x Mn1−x PO4/C nanocomposites (0≤ x ≤1.0) were prepared by a combination of spray pyrolysis at 300°C and wet ball-milling followed by heat treatment at 500°C for 4h in 3% H2 +N2 atmosphere. X-ray diffraction analysis indicated that all samples had the single phase olivine structures indexed by orthorhombic Pmna. The lattice parameters linearly decreased with increasing cobalt content, which confirmed the existence of solid solutions. It was clearly seen from the scanning electron microscopy observation that the LiCo x Mn1−x PO4/C samples were agglomerates with approximately 100nm primary particles. The LiCo x Mn1−x PO4/C nanocomposites were used as cathode materials for lithium batteries, and electrochemical performance was comparatively investigated with cyclic voltammetry and galvanostatic charge–discharge test using the Liǀ1M LiPF6 in EC:DMC=1:1ǀLiCo x Mn1−x PO4/C cells at room temperature. The cells at 0.05C charge–discharge rate delivered first discharge capacities of 165mAhg−1 (96% of theoretical capacity) at x =0, 136mAhg−1 at x =0.2, 132mAhg−1 at x =0.5, 125mAhg−1 at x =0.8 and 132mAhg−1 (79% of theoretical capacity) at x =1.0, respectively. While the first discharge capacity increased with the cobalt content at high charge–discharge rates more than 0.5C due to higher electronic conductivity of LiCoPO4 in comparison with LiMnPO4, the cycleability of cell became worse with increasing the amount of cobalt. The existence of Mn2+ seemed to enhance the cycleability of LiCo x Mn1−x PO4/C nanocomposite cathode.
Fuel-cell dynamics have been investigated with a variable-resistance board applied to a high-temperature polymer fuel cell, operating on pure oxygen and hydrogen at atmospheric pressure and about 150 °C. A particular pattern has been identified in the voltage–current density diagram. A model has been developed, using a characteristic equation to represent the external circuit as a resistive load, possibly nonlinear and time-varying, rather than assuming the current density to be an independent variable. The model successfully explains the shape of the transient current–voltage paths, including the different time constants observed when reversing a transient.
To restore unavoidable capacity losses, we propose a method of mixing and online electrolysis that resolves the imbalance of electrolyte concentration, volume and valence simultaneously. The cycle life of all-vanadium redox flow batteries is effectively prolonged at various current densities (120, 180, 240 and 300 mA cm−2) using different Nafion membranes (Nafion 212, Nafion 115 and Nafion 117). Besides, the total vanadium concentrations of the electrolytes detected by the titrator indicates minimal influence of electrolysis on the batteries. Although the capacity recovery decreases over long-term cycles, especially at the higher current density, this decrease is mainly due to the attenuation of the electrochemical performance of the electrodes, as evidenced by cyclic voltammetry curves. In addition, we conduct long-term cycle tests of 4140 and 5100 cycles, and we observe capacity retentions of 89.87% and 81.39% on batteries with Nafion 115 and Nafion 117, respectively, at the current density of 120 mA cm−2. Based on these results, we speculate that the method of mixing and online electrolysis can operate over indefinite cycles. This low-cost, convenient method, which does not need replacement of electrolytes, is beneficial to prospective applications in large-scale energy storage.
The electrochemical performance of Na0.45Ni0.22Co0.11Mn0.66O2 in an ionic liquid-based electrolytic solutions is reported and compared with that obtained in a conventional, carbonate-based electrolyte. Even at ambient temperature, the Na-ion intercalation material reveals a much better electrochemical performance in 10 mol% NaTFSI (or 0.45 M) in PYR14FSI electrolyte than 0.5 M NaPF6 in PC electrolyte in terms of specific capacity and cycling stability. In particular, the electrodes cycled in the IL-based electrolyte combine a capacity retention of about 80% after 100 cycles with high specific capacities (about 200 mAh g−1) and high average voltage (2.7 V vs. Na/Na+), demonstrating that Na0.45Ni0.22Co0.11Mn0.66O2 is a promising cathode material for sodium-ion batteries.
The properties of C3N/graphene heterostructures and their electrochemical performance serving as anodes for Li-ion batteries are systematically studied using density functional calculations. Present results demonstrate that C3N/graphene exhibits a metallic behavior, favorable stability and ultrahigh stiffness, which are well maintained even under the applied strains and after lithium adsorption, ensuring the electrode's good electric conductivity and integrity against pulverization. Most particularly, it is predicted that C3N/graphene possesses a maximum Li-storage theoretical capacity of 1079 mA h g−1, low average open-circuit voltages (0.13 V) and Li-diffusion barrier (0.28 eV). These encouraging findings indicate that C3N/graphene heterostructures can be appealing anode materials for Li-ion batteries.