batterydata/paper-abstracts huggingface dataset:
Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential. However, its unstable interface and low Coulombic efficiency, resulting from the dendritic growth of lithium, limits its commercial application. PIM-1 (PIM: polymer of intrinsic microporosity), which is a polymer with abundant micropores, exhibits high rigidity and flexibility with contorted spiro-centers in the backbone, and is an ideal candidate for artificial solid electrolyte interphases (SEI). In this work, a PIM-1 membrane was synthesized and fabricated as a protective membrane on the surface of an electrode to facilitate the uniform flux of Li ions and act as a stable interface for the lithium plating/stripping process. Nodule-like lithium with rounded edges was observed under the PIM-1 membrane. The Li@PIM-1 electrode delivered a high average Coulombic efficiency (99.7%), excellent cyclability (80% capacity retention rate after 600 cycles at 1 C), and superior rate capability (125.3 mAh g−1 at 10 C). Electrochemical impedance spectrum (EIS) showed that the PIM-1 membrane could lower the diffusion rate of Li+ significantly and change the rate-determining step from charge transfer to Li+ diffusion. Thus, the PIM-1 membrane is proven to act as an artificial SEI to facilitate uniform and stable deposition of lithium, in favor of obtaining a compact and dense Li-plating pattern. This work extends the application of PIMs in the field of lithium batteries and provides ideas for the construction of artificial SEI.
The accumulation of irreversible capacity in the first cycle and upon cycling has been studied for LiNi0.5Mn1.5O4-based cathodes (LNMO), bare and coated with ZnO. Materials have been synthesized at 800°C and characterized by X-ray diffraction and transmission electron microscopy (TEM). The precipitation of a continuous ZnO film on the surface of LNMO has been highlighted by TEM. Galvanostatic cycling at room temperature and at 60°C, linear sweep voltammetry (LSV), impedance spectroscopy and TEM techniques have been used to investigate the materials and the irreversible capacity accumulation upon cycling. Our study confirms that continuous parasitic processes occur upon cycling beyond the first charge/discharge. Anodic LSV test shows that side oxidation processes start on the surface of a LNMO electrode at potential slightly above the Ni2+/Ni4+ redox couple. At the end of charge an uniform and continuous thin film (3–4nm) forms of on the bare LNMO. This film likely modifies upon cycling and it is apparently unable to passivate the LNMO surface preventing further decompositions. On the contrary the material coated with ZnO shows rough surfaces without large morphological alteration upon charge and cycling. The ZnO coating confirms its ability to mitigate the irreversible charge consumption.
Fe2O3 as anode material for lithium ion batteries has been widely studied. However, structural pulverization and capacity fading induced by large volume change and low conductivity still limit its practical applications. In this work, Fe2O3/NiO/PPy and Fe2O3/Co3O4/PPy nanosheets were firstly constructed and investigated as anode materials for lithium ion batteries. The unique structures and the synergistic effect of the two components can effectively accommodate the strain of volume change, inhibit the pulverization and aggregation of the electrodes as well as enhance the electrical conductivity. Furthermore, the void spaces and interstitial sites in the Fe2O3/NiO/PPy and Fe2O3/Co3O4/PPy hybrids provide more lithium storage spaces and buffer spaces for the volumetric change during cycling. Benefiting from these advantages, the obtained Fe2O3/NiO/PPy and Fe2O3/Co3O4/PPy hybrids exhibit high reversible capacity, good cyclic performance and excellent rate capability. At the current density of 0.2 A g−1, the Fe2O3/NiO/PPy and Fe2O3/Co3O4/PPy display the discharge capacities of 1034 mAh g−1 and 922 mAh g−1 after 100 cycles, respectively. Even at high current density of 10 A g−1, the reversible capacities still maintain at 445 mAh g−1 for Fe2O3/NiO/PPy and 414 mAh g−1 for Fe2O3/Co3O4/PPy after long-term cycles (1000 cycles).
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors with the agreement of the Editor-in-Chief. The corresponding Author submitted the manuscript without the approval of all the collaborators in the work. The Authors apologise for this serious violation of the publishing policies, and they offer sincere apologies to their collaborator. The journal apologises to its readers. The appropriate work has been published as https://doi.org/10.1016/j.jpowsour.2014.07.087.
Self-administrated patient outcome scores are increasingly recommended for evaluation of primary outcome in clinical studies. The VISA-P score, developed at the Victorian Institute of Sport Assessment in Melbourne, Australia, is a questionnaire developed for patients with patellar tendinopathy and the patients assess severity of symptoms, function and ability to participate in sport. The aim of this study was to translate the questionnaire into Swedish and to study the reliability and validity of the translated questionnaire and resultant scores.
One-step electrosynthesis of polypyrrole (PPy)/graphene oxide (GO) composites on the graphite felt (GF) electrode was achieved by electropolymerization of pyrrole while using GO as the anionic dopant. The resulting PPy/GO composites were uniformly coated on the GF surface, with increased surface area, electronic conductivity, biocompatibility and stability as compared to PPy alone or graphene alone-modified GF electrode. The dual-chamber microbial fuel cell (MFC) equipped with the PPy/GO modified GF anode showed the maximum power density of 1326mWm−2 (obtained from linear sweep voltammetry at a scan rate of 0.5mVs−1), which was significantly larger than that associated with the unmodified GF anode (166mWm−2), the electrochemically reduced GO-modified GF anode (318mWm−2), the chemically reduced GO-modified GF anode (924mWm−2), and the PPy-modified GF anode (1100mWm−2). After 120 cycles of lactate feeding, the PPy/GO-GF anode exhibited good stability without noticeable performance degradation, but performance degradation was observed for the anodes modified with PPy alone or graphene alone. These results demonstrate that the PPy/GO composites, synthesized via the simple and facile electropolymerization approach, are effective anode modifying materials for improving electricity generation as well as long-term stability of MFCs.
This work describes optimized conditions for the use of cellulose acetate (CA), a naturally derived polymer, in gel electrolytes (GEs) for electrochromic devices (ECDs). The GEs were doped with lithium perchlorate (LiClO4) as a supporting salt electrolyte and propylene carbonate as a solvent. The conductivity of GEs with varying CA concentration was evaluated by a conductivity meter to determine the effectiveness of electrolyte ion transport in the GE matrix. Then, we employed poly(3-hexylthiophene-2,5-diyl) (P3HT) thin films as an electrochromic layer on an ITO substrate. The P3HT film served as the main cathodic electrochromic layer, the GE as an ion conducting layer, and a piece of bare ITO substrate as an anodic electrochromic layer. We evaluated the stability of the P3HT film by measuring the optical and electrochemical properties of P3HT thin films on ITO in GEs through UV–Vis and cyclic voltammograms obtained during application of potential to the films. Current/voltage data and related performance for ECDs were investigated. The results showed that the prepared GEs have high stability within the operative potential window for ECDs. The electrochromic polymer films operated with the prepared GE showed good stability with fully reversible color change for more than 1000 cycles without polymer film or GE degradation. This work shows the first example of the use of GE with a natural polymer matrix in electrochromic devices and demonstrates their reliability under repetitive switching of applied voltage for up to 1000 cycles.
In the present work, the ionic transport in copper tetrasulfonated phthalocyanine doped polyaniline (PANI/CuTsPc) film and its effects on the optical properties of the polymer is presented. The studies were performed in situ and in real time by using electrochemical surface plasmon resonance (ESPR) and electrochemical quartz crystal microbalance (EQCM). The electropolymerization was performed by potentiodynamic method and the EQCM experiments showed that the PANI/CuTsPc films behave rigidly validating the use of the Sauerbray equation. Both protonic and anionic participation in the charge compensation process were calculated and showed that the presence of the CuTsPc in the PANI film suppress the anionic transportation. Finally, the ESPR experiments showed that changes in the optical properties of the PANI/CuTsPc film were more expressive in the same potential range where the protonic transport was dominant.
We report the influence of nickel catalyst layer thickness when growing nickel silicide alloy nanowires below the liquefaction temperature through metal induced growth. Three different catalyst layer thicknesses show three different nanowire growth results that vary significantly the performance when used as an anode in a lithium ion solution. The thicker catalyst layers (70 nm) show pure NiSi nanowires which have an initial capacity of 1300 mAh g−1 that degrades to 550 mAh g−1 within 90 cycles. The thinner (30 nm thick) layer shows a heterogenous nanowire morphology comprising of a multicrystalline NiSi2 inside core and a Ni doped SiO amorphous shell with initial Li-ion capacity of 1727 mAh g−1 capacity that increases to 2468 mAh g−1 after 90 cycles. Samples with no catalyst layers were shown to grow pure silicon nanowires with poor surface coverage having an initial capacity of 1779 mAh g−1 that falls to 242 mAh g−1 after 90 cycles.
A study was conducted to identify sanitizing solutions effective at inactivating ca. 5logCFU of Salmonella enterica inoculated onto the stem scar of red round tomatoes during two-minute immersion treatments. Sixty-three antimicrobial combinations were tested. Vacuum perfusion was applied to tomatoes during selected treatments to promote infiltration of sanitizer into porous tomato stem scar tissue. Red round tomatoes were inoculated to ca. 6.9logCFU/stem scar with a four-serovar composite of Salmonella enterica, air dried, and tomatoes were immersed in circulating sanitizing solutions for 120s at ca. 22°C. Stem scars were aseptically excised, macerated in DE neutralizing broth, and the homogenate was spiral plated. Twenty-four washes inactivated ≥3.0logCFU/stem scar. Seven treatments reduced ≥4.8 log (viz., 40% EtOH, sulfuric acid, and organic acid combinations). LogCFU/stem scar reductions for various sanitizers are listed in parenthesis, as follows: 90ppm peroxyacetic acid (1.31), 200ppm chlorine (1.53), 190ppm chlorine+15″ Hg vacuum perfusion (2.23), 0.2N sodium hydroxide (NaOH) (3.78), 2% total of lactic+acetic acid (4.35), 3% total of phosphoric+lactic acids (4.51), and 40% ethanol (4.81). Solutions that achieved ≥4.95 log reductions were 5.1% total of lactic+acetic+levulinic acids, 49% ethanol, 6% total of lactic+acetic acids, and a 0.2M H2SO4 (sulfuric acid) solution. The use of vacuum perfusion with 200ppm chlorine increased inactivation by 0.7logCFU over chlorine alone, however, P>0.05. Results from this study provide tomato processers with some sanitization options effective at inactivating Salmonella from the stem scars of tomatoes. These results may also help processors and scientists design future decontamination studies by incorporating combinations of these chemical treatments.
A generalized three dimensional computational model based on unified formulation of electrode–electrolyte system of an electric double layer supercapacitor has been developed. This model accounts for charge transport across the electrode-electrolyte system. It is based on volume averaging, a widely used technique in multiphase flow modeling ([1,2]) and is analogous to porous media theory employed for electrochemical systems [3–5]. A single-domain approach is considered in the formulation where there is no need to model the interfacial boundary conditions explicitly as done in prior literature ([6]). Spatio-temporal variations, anisotropic physical properties, and upscaled parameters from lower length-scale simulations and experiments can be easily introduced in the formulation. Model complexities like irregular geometric configuration, porous electrodes, charge transport and related performance characteristics of the supercapacitor can be effectively captured in higher dimensions. This generalized model also provides insight into the applicability of 1D models ([6]) and where multidimensional effects need to be considered. A sensitivity analysis is presented to ascertain the dependence of the charge and discharge processes on key model parameters. Finally, application of the formulation to non-planar supercapacitors is presented.
Although Li-ion batteries have revitalized the energy storage platform, higher energy density for long-range applications is still a challenge. Beyond Li-ion, Li-S battery could be one of the most promising technologies, but challenges such as lithium polysulfide shuttling, sluggish reaction kinetics and low areal sulfur loading (<2.0 mg cm−2) remain. Herein, we report a multifunctional electrode composite consists of conducting polymer-carbon complex where the sulfur loading can reach as high as ∼75 wt %. Owing to high electrical conductivity and inherent heteroatom compositions of conductive polymers, composite electrodes are capable of suppressing polysulfide shuttling and enhance reaction kinetics via catalysis. As a result, these composite electrodes deliver outstanding electrochemical performance with the specific capacity of ∼1100 mAhg−1 for more than 100 cycles. A one-pot and straightforward procedure at ambient conditions to prepare these composite electrodes are demonstrated.
Power electronics DC–DC converters are being widely used in various applications like hybrid energy systems, hybrid vehicles, aerospace, satellite applications and portable electronics devices. In the recent past, a lot of research and development has been carried out to enhance the reliability, efficiency, modularity and cost effectiveness of these converters. A number of new topologies have been proposed and new characteristics of power conversion have been defined. DC–DC converters have made a successful transition from single input–single output to multiinput–multioutput converters. These converters are now able to interface different level inputs and combine their advantages to feed the different level of outputs. Research is continued to bring down the cost and reduce the number of components while keeping the continuous improvement in the areas like reliability and efficiency of the overall system. The study of different multiinput DC–DC converter topologies suggests that there is no single topology which can handle the entire goals of cost, reliability, flexibility, efficiency and modularity single handed. This paper presents some of the recent trends in the development of multiinput and multioutput DC–DC converters. Methods to synthesize multiinput converters, their operational principles, merits and demerits are studied.
We used high frequency repetitive transcranial magnetic stimulation (rTMS) to increase the excitability of perilesional regions after chronic brain damage to promote functional restitution. We specifically targeted rTMS to a perilesional area previously determined to be an essential site of functional compensation after focal damage to the posterior parietal cortex. A group of adult cats (n=6) underwent extensive behavioral testing in a battery of tasks requiring visually guided orienting responses to static visual stimuli presented at eccentricities throughout the left and right visual hemifields. Once plateau performance levels were reached, animals received unilateral cortical lesions of the posterior visuo-parietal cortex, which resulted in impairments in the ability to detect and localize visual stimuli in the contralesional visual hemispace. Three months after lesion, all subjects underwent daily sessions of rTMS (10Hz rTMS, 2400 pulses at 40% intensity) for seventy sessions. Animals were evaluated daily after each session of rTMS and after every block of 5 sessions. Following rTMS treatment, animals achieved either high, (n=4 subjects, 27±7%) moderate, (n=1 subjects, 17%) or no (n=1 subject, 0%) improvements in contralesional performance with respect to pre-TMS levels. Overall, recovery progressed from pericentral to peripheral targets with increasing rTMS sessions. A sham 10Hz TMS group (n=2) underwent an equivalent regimen and showed no changes in performance Our findings demonstrate that high frequency rTMS applied to perilesional cortical key areas is able to alleviate functional deficits in brain damaged subjects. These data have important implications for the use of rTMS to produce restitution in human patients afflicted by cerebral damage.
Bead-like nanocomposite Li3V2(PO4)3 (LVP) grown on carbon nanofiber (CNF) have been prepared by electrospinning and heat-treatment. The primary LVP crystals are squeezed together and grow outward because of the limitation of the reaction space for LVP precursors in PVP fiber, accompanying with the carbon nanofibers shrank in diameters. Compared with the traditional carbon-coated LVP, the combination of the “beads” (LVP nanoparticles) and the “string” (carbon fiber) are effective in conductivity and stability. A small amount of carbon content (5.27 wt%) in LVP/CNF is sufficient to enhance the rate performance and cycle ability. The initial discharge capacity of LVP/CNF is 196mAhg−1 at 0.1C, which is very close to the theoretical value (197mAhg−1) of pure LVP in 3.0-4.8V. In the long-term cycles at 20C-rate, LVP/CNF delivers the initial capacities of 127.5mAhg−1, and remains 102.0mAhg−1 at the 1000th cycle. Bead-like structure of LVP nanoparticles grown in carbon fibers is stable in thousands charge/discharge cycles at high current rate.
Simulating repeating loading events on dynamic systems can be challenging when large timescale disparities exist coupled with aperiodic effects. Batteries driving switched/pulsed loads represent one such situation. Large timescale disparity can be experienced by solid-state batteries driving switching microactuators or microelectronics, due to extremely short transient response times of microscale systems relative to some of the battery’s own dynamics. Projecting state changes over a long series of fast-timescale loading events using a transition matrix approach was shown previously to significantly reduce numerical expense of simulation compared to full modeling. Here we develop an approach for further accelerated simulation of a battery driving a microelectromechanical system (MEMS) actuator that quantifies errors and addresses overhead expenses in projecting battery states across multiple fast events. This is done with a definition of system states that allows efficient transition matrix generation, and an analysis of key errors associated with projection. This error analysis enables targeted modification to the transition matrix during projection. A case study explores these modeling approaches in a capacitively loaded, battery usage scenario of a piezoelectrically-driven microrobot where the proposed improvements reduce the numerical cost (function calls) by over 44x from the prior approach. Conditions for further simplified modeling are discussed.
A future for the E.U., dominated by an ever-increasing population of retired citizens represents a major challenge to social and health policy in European countries. Under Rowe and Kahn’s (Gerontol 37(4):433–440, 1997) perspective on positive aging, this paper is interested in exploring the role of health on citizens’ active participation after retirement and social engagement to life and quality of life. This paper also aims at finding whether Sen’s (Public health, ethics, and equity. Oxford University Press, Oxford, 2004) capability approach or cumulative disadvantage or advantage theory relative to the access to health also verifies in a context of multi-national developed economies. The first part of this study is therefore concerned with generating a health indicator that enables this, whilst controlling for individual heterogeneity in self-rated health responses from 10,859 retired individuals from the SHARE survey. Socioeconomic determinants of health are found not to be critical in determining health in such a developed context whilst cumulative advantage is found relevant for the positive aging of Europeans. Evidence is found that active engagement in activities and quality of life are most certainly a prerogative for the more educated and the healthier retirees, hinting a strategy for European policymakers: cumulative advantage, leveraged by education and health policy, might just be the long-term strategy for contouring an aging and unproductive European population, transforming what could be a ‘burden’ into an asset.
Nitrogen-doped carbons are suggested as electrochemically active materials for V(IV)/V(V) redox couples for a vanadium redox flow battery (VRB). These materials were synthesized using a hydrothermal reaction of aqueous glucose solution in the presence of ethylenediamine as a nitrogen source. The physical and electrochemical properties of the nitrogen-doped carbons are characterized by cyclic voltammetry, high-resolution transmission electron microscopy and X-ray photoelectron spectrometry. These results reveal that the hydrothermal method is an effective way to synthesize high-content nitrogen-doped carbons. Nitrogen doping significantly improves catalytic activity and reversibility. Therefore, use of nitrogen-doped carbon is expected to increase the energy storage efficiency of VRBs.
Poly(vinylidene fluoride-co-hexafluoropropylene) {P(VdF-HFP)} membranes incorporating 0, 6 and 10wt.% of nano-meter sized particles of SiO2 were prepared by electrospinning. These membranes served as host matrix for the preparation of polymer electrolytes (PEs) by activating with the non-volatile and safe room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) (BMITFSI). The membranes consisted of layers of fibers with average fiber diameter of 2–5μm and had a porosity of ∼87%. PEs with SiO2 exhibited higher ionic conductivity with a maximum of 4.3×10−3 Scm−1 at 25°C obtained with 6% SiO2. The optimum PE based on the membrane with 6% SiO2 exhibited better compatibility with lithium metal electrode on storage and resulted in enhanced charge–discharge performance in Li/LiFePO4 cells at room temperature, delivering the theoretical specific capacity of 170mAhg−1 at 0.1C-rate. The PEs exhibited a very stable cycle property as well, demonstrating their suitability for lithium battery applications.
The dynamic behavior of the three-phase interface on a platinum electrode during oxygen reduction (ORR) and oxygen evolution reactions (OER) in a potassium hydroxide droplet was studied by a charge-coupled device (CCD) and confocal laser microscopy. Contact angle measurements reveal a spreading interface during ORR, whereas the droplet figure remains unchanged during OER. The microscopy results demonstrated the formation of many fine droplets in the vicinity of the meniscus boundary during ORR, which was attributed to vapor condensation on the surface. Correlation of these observations with electrochemical data and differences in the results between ORR and OER suggest that the motion of the three-phase interface is induced by local pH and temperature gradients in the meniscus, presumably caused by ORR uniformity under the limitation of dissolved oxygen.