batterydata/paper-abstracts huggingface dataset:
The oxygen reactions in a metal-air battery during discharge (oxygen reduction reaction: ORR) and charge (oxygen evolution reaction: OER) take place on accessible catalyst sites at the gas diffusion electrode (GDE or air-cathode). Typical low-cost catalysts only have function for either the ORR (e.g. MnO2) or the OER (e.g. NiCo2O4). To overcome this issue, either a bifunctional catalyst or a bifunctional GDE is needed. Herein, we focus on the development of such a bifunctional GDE. One key is the use of a carefully tuned binder which allows optimal wetting of the GDE. The combination of carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) can replace conventional binders such as polytetrafluoroethylene (PTFE). Using this binder system, two different approaches to combine the two catalysts γ-MnO2 and NiCo2O4 in one cathode are employed. The first is to mix the ORR catalyst γ-MnO2 and the OER catalyst NiCo2O4 for integration in the same reactive layer. The second is to build a GDE with two reactive layers which are screen printed on top of each other. The reactive layer facing the air side consists of the ORR catalyst γ-MnO2 and the binders CMC/SBR. The second reactive layer, facing the electrolyte, consists of the hydrophilic binder CMC and the OER catalyst NiCo2O4. This double-layer design with two different catalyst species results in a better cycling behavior.
As portable electronics become more advanced and alternative energy demands become more prevalent, the development of advanced energy storage technologies is becoming ever more critical in today's society. In order to develop higher power and energy density batteries, innovative electrode materials that provide increased storage capacity, greater rate capabilities, and good cyclability must be developed. Nanostructured materials are gaining increased attention because of their potential to mitigate current electrode limitations. Here we report on the use of vertically aligned multi-walled carbon nanotubes (VA-MWNTs) as the active electrode material in lithium-ion batteries. At low specific currents, these VA-MWNTs have shown high reversible specific capacities (up to 782mAhg−1 at 57mAg−1). This value is twice that of the theoretical maximum for graphite and ten times more than their non-aligned equivalent. Interestingly, at very high discharge rates, the VA-MWNT electrodes retain a moderate specific capacity due to their aligned nature (166mAhg−1 at 26Ag−1). These results suggest that VA-MWNTs are good candidates for lithium-ion battery electrodes which require high rate capability and capacity.
Synthesis, electrochemical, and structural properties of LiNi0.8Co0.15Al0.05O2 cathodes prepared by TiO2 nanoparticles coating on a Ni0.8Co0.15Al0.05(OH)2 precursor have been investigated by the variation of coating concentration and annealing temperature. TiO2-coated cathodes showed that Ti elements were distributed throughout the particles. Among the coated cathodes, the 0.6wt% TiO2-coated cathode prepared by annealing at 750°C for 20h exhibited the highest reversible capacity of 176mAhg−1 and capacity retention of 92% after 40 cycles at a rate of 1C (=190mAg−1). On the other hand, an uncoated cathode showed a reversible first discharge capacity of 186mAhg−1 and the same capacity retention value to the TiO2-coated sample at a 1C rate. However, under a 1C rate cycling at 60°C for 30 cycles, the uncoated sample showed a reversible capacity of 40mAhg−1, while a TiO2-coated one showed 71mAhg−1. This significant improvement of the coated sample was due to the formation of a possible solid solution between TiO2 and LiNi0.8Co0.15Al0.05O2. This effect was more evident upon annealing the charged sample while increasing the annealing temperature, and at 400°C, the coated one showed a more suppressed formation of the NiO phase from the spinel LiNi2O4 phase than the uncoated sample.
This study tested the common assumption that, to be most effective, working memory (WM) training should be adaptive (i.e., task difficulty is adjusted to individual performance). Indirect evidence for this assumption stems from studies comparing adaptive training to a condition in which tasks are practiced on the easiest level of difficulty only [cf. Klingberg (Trends Cogn Sci 14:317–324, 2010)], thereby, however, confounding adaptivity and exposure to varying task difficulty. For a more direct test of this hypothesis, we randomly assigned 130 young adults to one of the three WM training procedures (adaptive, randomized, or self-selected change in training task difficulty) or to an active control group. Despite large performance increases in the trained WM tasks, we observed neither transfer to untrained structurally dissimilar WM tasks nor far transfer to reasoning. Surprisingly, neither training nor transfer effects were modulated by training procedure, indicating that exposure to varying levels of task difficulty is sufficient for inducing training gains.
Bare reticulated vitreous carbon (RVC) plated electrochemically with thin layer of lead was investigated as a negative plate carrier- and current-collector material for lead-acid batteries. Hybrid flooded single cell lead-acid batteries containing one negative plate based on a new type (RVC or Pb/RVC) of carrier/current-collector and two positive plates based on Pb–Ca grid collectors were assembled and subjected to charge/discharge tests (at 20-h and 1-h discharge rates) and Peukert's dependences determination. The promising results show that application of RVC as carrier- and current-collector in negative plate will significantly increase the specific capacity of lead-acid battery.
In this study, methanesulfonic acid has been investigated as the supporting electrolyte for vanadium solutions due to the improvement of mass transfer rate and reaction kinetics. Here, we applied different temperatures (0–55°C) for electrochemical experiments of 0.1M vanadium ions in 1.0M MSA electrolyte on gold, platinum and glassy carbon electrodes separately to study the temperature-related kinetics. Considering that electron transfer is the control path for the whole reduction potential window, the rotating disc electrode approach was utilized for the oxidation of V(IV) ions, while the reduction of V(V) ions was studied by cyclic voltammetry. The influence of temperature on charge-transfer resistance and mass transport for both V(IV) and V(V) solutions was studied by electrochemical impedance spectroscopy on glassy carbon electrode. The results showed that the diffusion coefficients in both redox reactions on all electrodes increased with temperature, and most were in the order of 10−6 cm2 s−1. The positive influence of temperature was also observed on the standard rate constants for all conditions in this study, most significantly on the glassy carbon electrode. Comparison between glassy carbon electrode and metal electrodes indicates a promising potential of carbon-based material as electrode for redox flow battery.
Publisher Summary This chapter gives an overview of maintenance welding. Welding machines and electrodes have been developed to the point where reliable welding can be accomplished under the most adverse circumstances. Besides making quick, on-the-spot repairs of broken machinery parts, welding offers the maintenance department a means of making many items needed to meet a particular demand promptly. The welding involved should present no particular problems if the operators have the necessary training and background to provide them with knowledge of the many welding techniques that can be used. A maintenance crew proficient in welding can fabricate and erect many of the structures required by a plant, even to the extent of making structural steel for a major expansion. Welding can be done either in the plant maintenance department or on the erection site. Standard structural shapes, including pipe, which makes an excellent structural shape, can also be used. Electrodes such as the E6010-11 types are often the welder's first choice for this kind of fabrication welding because of their all-position characteristics. Scrap materials often can be put to good use. When using scrap, however, it is best to weld with a low-hydrogen E7016-18 type of electrode, since the analysis of the steel is unlikely to be known and some high carbon steels may be encountered. Low-hydrogen electrodes minimize cracking tendencies. Structural scrap frequently comes from dismantled structures such as elevated railroads, which use rivet-quality steel that takes little or no account of the carbon content. This chapter also explains gas tungsten arc welding, including its advantages and disadvantages.
Exceptional elevated temperature performance of high voltage spinel cathodes are realized by LiFePO4 coating in a single-step process at 600°C under Ar flow. First, the single-phase spinel LiNi0.5Mn1.5O4 is prepared via sol-gel route by optimizing the adipic acid concentration (0 - 1mol.). Then, the high performing spinel phase (0.7mol. adipic acid treated) is subjected to LiFePO4 modification by conventional two-step coating procedure with various coating concentrations (1-3wt.%). Single-step LiFePO4 coating procedure also performed at 550°C under Ar atmosphere for the comparison. Although LiFePO4 modified LiNi0.5Mn1.5O4 delivered appreciable performance in elevated temperature (55°C), but it is not sufficient for the practical applications. Therefore, fine tuning of the LiFePO4 (1wt.%) formation temperature (500-600°C) have been varied to achieve excellent electrochemical profiles at elevated temperature conditions. The presence of thin LiFePO4 have been confirmed by high resolution TEM studies and supported well with EDAX measurements.
Li3V2(PO4)3 nanocrystals (5–8 nm) embedded in a nanoporous carbon matrix attached onto reduced graphene oxide nanosheets (LVP-NC@NPCM@rGO) are synthesized by a facile approach. The rGO sheets not only form the interconnected conducting scaffold to enhance the charge transfer but also act as the heterogeneous nucleation site to facilitate the growth of nanograins of LVP. The nanoporous carbon acts as the nanocontainer to enhance the electrolyte/active material interaction and also inhibit the grain growth of Li3V2(PO4)3. This leads to the fast kinetics of the Li ion transfer and the excellent cathode performance, especially at high current densities. Binder-free cathodes can be prepared based such LVP-NC@NPCM@rGO sample, which shows high specific capacities, stable cyclabilities and excellent rate capabilities in the voltage ranges of 3.0–4.3 and 3.0–4.8 V.
Given the relentless growing number of mobile devices, researchers have pointed out that distributed computing environments, such as clusters or even computational Grids, could increase the available resources by scavenging devices’ capabilities. However, this negatively impacts on their batteries. We study centralized job schedulers that aim at exploiting clusters of mobile resources with rather stable devices in terms of connection time. These schedulers outperform a previous centralized scheduler, finishing up to 30% more jobs with the same amount of energy. We also show that the schedulers perform competitively compared to schedulers based on job stealing, which are more difficult to implement and consume more network resources and hence energy.
Background The diagnosis of Specific Language Impairment (SLI) is very complex, given the variety of clinical pictures described in this disorder. Knowledge about the linguistic markers of SLI can facilitate its differentiation from the normal profile of language development. These markers can also be used as tools that may improve diagnostic. Aims To determine which psycholinguistic markers best discriminate Spanish-speaking children with SLI from children with typical language development. Method and procedure The performance of 31 Spanish-speaking children with SLI was analysed using a battery of 13 psycholinguistic tasks organized into two areas: phonology and morphosyntax. The performance of the SLI group was compared to that of two subgroups of controls: aged matched (CA) and linguistically matched (CL). Outcomes and results The data show that the SLI group performed worse than the CA subgroup on all 13 verbal tasks. However, the performance of the SLI group did not significantly differ from that of the CL subgroup on most (11/13) of the tasks. Stepwise discriminant analysis established the canonical function of three tasks (morphologic integration, sentence understanding and diadochokinesis) which significantly discriminated SLI from CA, with sensitivity 84% and specificity 90%. Conclusions and implications These results contribute to determining the psycholinguistic and clinical characteristics of SLI in Spanish-speaking children and provide some methods for screening assessment.
A novel numerical model for simulating the behavior of lithium-ion batteries based on LiFePO4(LFP)/graphite is presented. The model is based on the modified Single Particle Model (SPM) coupled to a mesoscopic approach for the LFP electrode. The model comprises one representative spherical particle as the graphite electrode, and N LFP units as the positive electrode. All the SPM equations are retained to model the negative electrode performance. The mesoscopic model rests on non-equilibrium thermodynamic conditions and uses a non-monotonic open circuit potential for each unit. A parameter estimation study is also carried out to identify all the parameters needed for the model. The unknown parameters are the solid diffusion coefficient of the negative electrode (D s,n ), reaction-rate constant of the negative electrode (K n ), negative and positive electrode porosity (ε n &ε n ), initial State-Of-Charge of the negative electrode (SOC n,0 ), initial partial composition of the LFP units (y k,0 ), minimum and maximum resistance of the LFP units (R min &R max ), and solution resistance (R cell ). The results show that the mesoscopic model can simulate successfully the electrochemical behavior of lithium-ion batteries at low and high charge/discharge rates. The model also describes adequately the lithiation/delithiation of the LFP particles, however, it is computationally expensive compared to macro-based models.
We report an 11-year-old girl for whom the diagnosis of cri du chat syndrome (CdCS) was made during a genetic investigation of childhood apraxia of speech. The patient presented with the classic chromosome 5 short arm deletion found in CdCS. The microdeletion, characterised using aCGH (array Comparative Genomic Hybridisation), was 12.85 Mb, overlapping the 5p15.2 and 5p15.3 critical regions. CdCS is typically associated with severe mental retardation while this patient had normal intellectual performance, confirmed by normal results from categorisation tasks. This mild phenotype was assessed using a comprehensive cognitive battery. Language evaluation showed normal receptive vocabulary scores, in contrast with obvious oro-facial dyspraxia. Disabled fine motor skills were confirmed as well as weak visuo-spatial reasoning abilities. In conclusion, fine cognitive assessment may be worthwhile for patients with CdCS since good intellectual functioning may be masked by severe speech and gestural dyspraxia, thus requiring specific teaching and rehabilitation strategies.
Despite the growing recognition that metropolitan real estate markets are segmented spatially and that property development is still profoundly local, research has taken little notice of agents that actually initiate and propel the development process. Earlier studies that aimed at identifying metropolitan segmentation employed statistical techniques whilst ignoring the practices of agents that might shed light on the notion of segmentation. Greater Toronto’s office market, which is Canada’s largest, exemplifies a real estate market far more spatially segmented than the downtown–suburban framework, a dichotomy so extensively use in research. Locational preferences of the numerous developers that work in this market tend to be highly localized, confirming deep-rooted segmentation. Their preferences correspond to submarket classification and follow dividing lines that crisscross the metropolitan region, emphasizing the extent and the power of parochialism, which defines the nature of real estate development.
Sixteen ionic liquids (ILs) based on two new asymmetric imide anions, (fluorosulfonyl)(polyfluorooxaalkanesulfonyl)imide {[(FSO2)(XCF2CF2OCF2CF2SO2)N]−, [5X3O-FOFSI]−, X=H and I}, are synthesized and characterized by in combination with various oniums, including 1,3-dialkylimidazolium, quaternary alkyl (or ether-functionalized alkyl)ammonium, N-alkyl-N-methyl-pyrrolidinium and -piperidinium. Their physicochemical properties are investigated, in terms of phase transitions, thermal stability, density, viscosity, ionic conductivity, electrochemical stability, and the capability as electrolytes to allow Li deposition/stripping. The influences of the structural variations in both the cations and anions, particularly introduction of an ether group into the anion, on the above properties are systematically studied. All the ILs are liquids at room temperature and show low glass transition temperatures, suggesting the high flexibility of the ether-functionalized imide anion. It has been demonstrated that only having an ether group into the polyfluoroalkyl chain of the imide anion affect neither the cathodic nor anodic stability of the anion and their ILs. The ILs based on the [5H3O-FOFSI]− anion have an enough electrochemical stability to allow Li deposition/striping, while those based on the [5I3O-FOFSI]− anion show relatively low cathodic stability due to the presence of a CI bond in the anion.
Poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), and poly(vinyl alcohol) (PVA), which have oxygen species as functional groups, were utilized as a binder for graphite electrodes, and the electrochemical reversibility of lithium intercalation was examined in PC medium and ionic liquid electrolyte, lithium bis(trifluoromethanesulfonyl)amide dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide (BMP-TFSA). Columbic efficiency of 75–80% with more than 300mAhg−1 was achieved upon first reduction/oxidation cycle in both electrolytes using these binding polymers, which were significantly improved in comparison to a conventional PVdF binder (less than 45% of columbic efficiency for the first cycle). For the graphite-PVdF electrode, co-intercalation and/or decomposition of PC molecules solvating to Li ions were observed by the electrochemical reduction, resulting in the cracking of graphite particles. In contrast, the co-intercalation and decomposition of PC molecules and BMP cations for the first reduction process were completely suppressed for the graphite electrodes prepared with the polymers containing oxygen atoms. It was proposed that the selective permeability of lithium ions was attained by the uniform coating of the graphite particles with PAA, PMA, and PVA polymers, because the electrostatic interaction between the positively charged lithium ions and negatively charged oxygen atom in the polymer should modulate the desolvation process of lithium ions during the lithium intercalation into graphite, showing the similar functions like artificial solid-electrolyte interphase.
The aim of the paper is to propose an approach for statistical assessment of the potential of plug-in electric vehicles (PEV) for vehicle-to-grid (V2G) ancillary services, where it focuses on PEVs doing daily home-work commuting. In this approach, the possible ancillary services (A/S) for each PEV fleet in terms of its available V2G power (AVP) and flexible intervals are identified. The flexible interval is calculated using a powerful stochastic global optimization technique so-called “Free Pattern Search” (FPS). A probabilistic method is also proposed to quantify the impacts of PEV’s availability uncertainty using the Gaussian mixture model (GMM), and interdependency of stochastic variables on AVP of each fleet thanks to a multivariate modeling with Copula function. Each fleet is analyzed based on its aggregated PEV numbers at different level of distribution grid, in order to satisfy the ancillary services localization limitation. A case study using the proposed approach evaluates the real potential in Niort, a city in west of France. In fact, by using the proposed approach an aggregator can analyze the V2G potential of PEVs under its contract.
Doping of cathode materials can considerably improve electrochemical performance and stability. Here, the high-voltage LiNi0.5Mn1.5O4 spinel is used as a candidate material. It is high-voltage cycling at a potential of approximately 4.7 V and the ability to host 2 eq. Li, thus leading to a theoretical capacity of 294 mAh g−1, that makes this material interesting. In order to improve stability and electronic conductivity, the spinel is doped with titanium and iron. Cycling in a voltage range of 2.0–5.0 V leads to a cooperative Jahn-Teller distortion accompanied by a phase transformation from cubic to tetragonal symmetry. This causes a severe capacity fade. To improve capacity retention, the as-prepared spinel is post-doped with fluorine. Influence of different fluorine amounts in LiNi0.5Mn1.4Fe0.1Ti0.027O4−xFx (x = 0–0.3) on the capacity and stability is analyzed. The initial capacities decrease with increasing fluorine content but the low voltage capacity is stabilized. Best electrochemical results are obtained with a fluorine content of x = 0.15. Furthermore, an additional redox couple is found. The intensity of this depends on the fluorine content. It is assumed that manganese, either in the tetrahedral sites or in octahedral sites, bound to fluorine lead to a higher voltage.
A low pressure nickel–hydrogen battery using either a metal hydride or gaseous hydrogen for H2 storage has been developed for use in implantable neuroprosthetic devices. In this paper, pressure variations inside the cell for the gaseous hydrogen version are analyzed and correlated with oxygen evolution side reaction at the end of charging, the recombination of oxygen with hydrogen during charging and a subsequent rest period, and the self-discharge of the nickel electrode. About 70% of the recombination occurred simultaneously with oxygen evolution during charging and the remaining oxygen recombined with hydrogen during the 1st hour after charging. Self-discharge of the cell varies linearly with hydrogen pressure at a given state of charge and increased with increasing battery charge levels. The coulometric efficiency calculated based on analysis of the pressure–time data agreed well with the efficiency calculated based on the current–time data. Pressure variations in the battery are simulated accurately to predict coulometric efficiency and the state of charge of the cell, factors of extreme importance for a battery intended for implantation within the human body.
Micro-probe Raman spectroscopy investigation of LiCoPO4 composite electrodes performed after prolonged cycling in LiPF6 EC/DMC electrolyte solution revealed total structural degradation of the olivine structure of the electrodes. The electrodes cycled in the identical conditions but in the presence of the HF-scavenging glassy fiber (GF) separators retain their olivine structure unchanged. The reasons for this pronounced difference are discussed.
Recycling of Li-ion batteries (LIBs) is becoming an urgent issue. However, the chemical composition and the hazard of off-gas produced during the recycling process still remain unclarified due to the complicated reactions during thermal runaway (TR). In order to meet the legislative requirements to carry out an environmentally friendly recycling, this manuscript aims to undertake quantitative analysis and toxicity evaluation of the off-gas produced in mechanical treatment and thermal treatment of LIBs. The measurements were carried out by online Fourier transform infrared spectroscopy (FTIR) and ion chromatograph (IC). The volume of total off-gas was calculated and its toxicity was evaluated by USA’s Protective Action Criteria. The influences of treatment method, state-of-charge (SOC), atmosphere, and type of cathode were investigated.