batterydata/paper-abstracts huggingface dataset:
An easy to fabricate and versatile cell that can be used with a variety of electrochemical techniques, also meeting the stringent requirement for undertaking cyclic voltammetry under transient conditions in in situ electrocrystallization studies and total external reflection X-ray analysis, has been developed. Application is demonstrated through an in situ synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD) characterization of electrocrystallized cadmium (II)-tetracyanoquinodimethane material, Cd(TCNQ)2, from acetonitrile (0.1moldm−3 [NBu4][PF6]). Importantly, this versatile cell design makes SR-GIXRD suitable for almost any combination of total external reflection X-ray analysis (e.g., GIXRF and GIXRD) and electrochemical perturbation, also allowing its application in acidic, basic, aqueous, non-aqueous, low and high flow pressure conditions. Nevertheless, the cell design separates the functions of transient voltammetry and SR-GIXRD measurements, viz., voltammetry is performed at high flow rates with a substantially distended window to minimize the IR (Ohmic) drop of the electrolyte, while SR-GIXRD is undertaken using stop-flow conditions with a very thin layer of electrolyte to minimize X-ray absorption and scattering by the solution.
As the lightest and most electropositive material, lithium metal is regarded as the ultimate anode material for next-generation high-energy batteries. However, uncontrolled dendritic lithium growth as well as low Coulombic efficiency hinders its widespread application in secondary batteries. Interfacial modification of anodes with protective layers has been proved to be an effective way to inhibit the growth of ramified lithium. Here we report on a freestanding, highly flexible nanostructured carbon film, which is ready to be transferred onto electrodes with great ease. We show that such mechanically robust carbon films can effectively suppress the growth of Li dendrites upon cycling at practical current densities (0.25–1.0mAcm−2) with significantly improved Coulombic efficiency up to ~99.5% for over hundreds of cycles and thousands of operation hours. Notably, this semi-tubular carbon film demonstrated instant, reliable protection to electrodes in not only reactive electrolytes but also ambient environment with high humidity, offering a practically feasible route toward the dendrite-free lithium metal batteries.
Disordered surface of anode materials accompanied by oxygen vacancies, has been developed as an efficient strategy to promote their charge-transfer kinetics and then improve their electrochemical properties. It is rarely explored for cathode materials before. Here, LiTi2-x Mn x (PO4-y )3 nanoparticles with a disordered surface and oxygen vacancies, are synthesized by a hydrothermal method following with an annealing in Ar/H2. Their disordered surface and heteroatom doping by reduced Mn/Ti species, have been supported by HRTEM images, XPS and EDS spectra. After 120 cycles at 0.2 C, these nanoparticles still deliver a capacity of 127 mAh g−1, much higher than the product without any doping, and that without a disordered surface. Even after 500 cycles, the capacity is still at 101 mAh g−1 for 5 C or at 71 mAh g−1 for 20 C. These results could be attributed to the reduced charge-transfer resistance caused by disordered surface, and the enhanced lithium-diffusion induced by doping.
H2V3O8 nanobelts have been successfully synthesised from commercial V2O5 powder through a fast and environmental friendly microwave-hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy, high-resolution transmission electron microscopy and ICP spectroscopy were used to characterise the morphology and structure–microstructure details. Nanobelts about 100 nm wide and several micrometres long are easily prepared in no more than 2 h. The electrochemical study reveals the reversible insertion of ca. 4 Li per formula unit (400 mAh g−1), through several pseudo-plateaus in the 3.75–1.5 V vs Li+/Li voltage range showing the interest of this material produced by a “green” route as an electrode for lithium rechargeable batteries. After the first cycle a significant capacity loss is observed, though a high capacity, ca. 300 mAh g−1, remains upon cycling. Furthermore, the similarity of discharge and charge curves, pointing to the absence of hydrogen displacement during lithium insertion in H2V3O8, shows that not all protonated systems must be discarded as prospective electrode materials. On the other hand, further reduction down to 1 V is possible to insert up to 5 Li per formula unit (480 mAh g−1). Interestingly it corresponds to full reduction of vanadium to V3+ as it is also confirmed by EELS experiments. However, the full reduction to V3+ is associated with a fast decay of the extra capacity developed at low voltage with increasing current rate. Then for practical use we may consider only the capacity obtained down to 1.5 V.
Understanding the activity and stability of oxygen-evolving anodes is crucial for developing better water splitting electrolysers. Researchers now show the importance of interactions between iron and hydr(oxy)oxide hosts in dynamically-stable electrocatalysts that balance dissolution and deposition of iron present in the electrolyte.
We report the characterization of a redox polyelectrolyte based on ferrocenated imidazolium and imidazole repeating units to evaluate the impact of the charged structure on the electron transfer rates. N-vinyl-N′-(methylferrocene)imidazolium chloride monomer was polymerized in the presence of various amounts of vinylimidazole to obtain the electroactive heteropolymer, as the homopolymerization was unsuccessful due to electrostatic repulsion between the imidazolium monomers. NMR was used to determine the ratio of electroactive to neutral monomers in the polymer. The electrochemistry of a thin film of the polymer casted on the surface of glassy carbon electrode was studied in 1 M NaClO4 aqueous electrolyte. Cyclic voltammetry at low scan rates (i.e. ν < 0.1 V s−1) showed a response close to the expected behavior for a surface-confined process without any significant interactions between the ferrocene redox centers, in contrast with poly(vinylferrocene). At high scan rates (ν > 1 V s−1); the behavior was diffusion-controlled. The diffusion coefficient of the ferrocene centers in the imidazolium polymer is 1.7 × 10−9 cm2 s−1 which is one order of magnitude higher than poly(vinylferrocene), and the standard rate constant, determined by the Nicholson's approach, was k0 = 3.8 × 10−4 cm s−1. These high values are explained by favorable interactions of the electrolyte with the charged imidazolium, providing a fast ion diffusion and pairing with ferrocenium. The potential use of this redox polymer in electrochemical systems is demonstrated via the formation of a composite with electrochemically exfoliated graphite to increase polymer loading.
Background Previous studies indicate that transcranial direct current stimulation (tDCS) with anode over motor cortex (M1) and cathode over contralateral supraorbital region (SO) may be effective in reducing pain, but these studies are limited in number and have not focused on older adults with osteoarthritis (OA). Objective To evaluate the preliminary efficacy and safety of M1-SO applied tDCS on clinical pain severity and mobility performance in adults with knee OA pain. Methods Forty 50- to 70-year-old community-dwelling participants with knee OA were randomly assigned to receive five daily sessions of 2 mA tDCS for 20 min (n = 20) or sham tDCS (n = 20). We measured clinical pain severity via Numeric Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index, and Short-Form McGill Pain Questionnaire. In addition, we measured mobility performance using the 6-Minute Walk Test and the Short Physical Performance Battery. Moreover, we obtained a sensation/safety questionnaire and measured cognition changes using the PROMIS-Applied Cognition-Abilities-Short Form 8a. Results Active tDCS over M1-SO significantly reduced Numeric Rating Scale of pain compared to sham tDCS after completion of the five daily sessions, and remained up to three weeks. No other measures were significantly different from sham. Participants tolerated tDCS over M1-SO well without serious adverse effects or cognition changes. Conclusion Although not consistent in all pain measurements, our findings demonstrate promising clinical efficacy for reduction in pain perception for older adults with knee OA. Trial registration ClinicalTrials.gov Identifier NCT02512393.
Porous graphitic carbon materials (PGCs) with a microtubular structure were synthesized by a simple method simultaneously completing graphitization and activation for the mixture of willow catkins, KCl, and different ferric salts. The introduction of KCl was crucial to develop a porous structure. KCl, replacing corrosive KOH or poisonous ZnCl2, greatly decreased the cost for production of PGCs. The resulting material PGCN, which was produced by willow catkins, KCl, and Fe(NO3)3, not only inherited the natural microtubular morphology of willow catkins but also possessed a high graphitization degree and abundant porosity. As such, PGCN could serve as an ideal substrate for MnO2 deposition to alleviate its accumulation and improve its conductivity. The obtained PGCN/MnO2 composite electrode significantly enhanced high specific capacitance 571.1 F g− 1 at 2 A g− 1 based on the mass of MnO2. Even at a high current density of 50 A g− 1, specific capacitance still reached 382.1 F g− 1. Furthermore, the electrode exhibited outstanding cycling stability with only 14.8% degradation after 3000 cycles. This study proposes a novel graphitization–activation way for synthesis of porous graphitic carbon by utilizing biomass waste to alleviate the dependence on non-renewable sources.
The cathode material, LiNi0.8Co0.2O2 was synthesized by acid dissolution method using lithium carbonate, nickel hydroxide (carbonate), cobalt hydroxide (carbonate) as insoluble starting materials, and acrylic acid, which acts as an organic acid as well as a chelating agent. Structural and chemical characterization of the spray-dried xerogel precursor was performed through its compositional and thermogravimetric analysis (TGA), which shows that the xerogel can be expressed as Li[MA]3, where M is the transition metal atom. The electrochemical performance of the synthesized powder was tested manufacturing the coin-type cells with lithium metal as an anode material. With the voltage range of 3.0–4.2V, the capacity retentions after 50 cycles were 98.6 and 94.5%, respectively, for the powders calcined at 800°C for 15 and 20h. At the rate capability test, discharge capacity ratio between 3.0 and 0.5C rate is about 91–84% till 60 cycles.
This paper presents a detailed analysis of the levelized cost of storage (LCOS) for different electricity storage technologies. Costs were analyzed for a long-term storage system (100MW power and 70GWh capacity) and a short-term storage system (100MW power and 400MWh capacity). Detailed data sets for the latest costs of four technology groups are provided in this paper. The LCOS method allows a cost comparison of technologies in different system designs and various operation modes. The results for the long-term storage show that Pumped-Storage Hydroelectricity has the lowest LCOS among the mature technologies today. Power to Gas technologies, once established on the market, may also provide long-term electricity storage at even lower LCOS. Pumped-Storage Hydroelectricity is also the cheapest technology for short-term storage systems. Battery systems at the moment still have high costs but are expected to have a sharp price decrease in the near future. Power to Gas and adiabatic Compressed Air Energy Storage systems may become cost competitive as short-term storage systems as well. The detailed analysis of the cost components shows that the cost composition is very inhomogeneous among the technologies. Plant design optimized to the application is therefore crucial for cost minimization. Sensitivity analysis shows that for most technologies the amount of energy discharged as well as the cost of electricity purchase are the most influential factors for the LCOS.
Currently it is very difficult for connection oriented applications to use a mobile environment. One reason is that Mobile IP requires intermediate software agents to be deployed in the Internet. This infrastructure based mobility scheme offers connectivity to itinerant hosts but incurs significant handoff and tunneling delays along with deployment costs. These delays are particularly harmful for connection oriented applications. In this paper we investigate an alternate mobility scheme which does not require any such infrastructure but only uses an end-point technique and interestingly provides much faster loss-free handoff for connection oriented applications. This End-to-End scheme named Interactive Protocol for Mobile Networks (IPMN) intelligently performs handoff based on information provided by MAC Layer. The network address change is handled by renewing the existing connections by manipulating the TCP/IP stack at the end-points. Also, unlike several other recently proposed end-to-end techniques which require extensive modification of end-protocols, the proposed scheme does not require any functional change in the TCP/IP protocol software. Besides the difference in deployment scenarios, the IPMN offers blazingly fast event based handoff and much faster and simplified transport (no tunneling delay) than MIP. We have implemented IPMN over FreeBSD. In this paper we show the performance advantage of IPMN over MIP with real deployment for three interesting real-time traffic types — www, voice streaming and, steerable/interactive time critical video.
Single walled carbon nanotubes (SWCNT) find their way in various industrial applications. Due to the expected increased production of various carbon nanotubes and nanoparticle containing products, exposure to engineered nanoparticles will also increase dramatically in parallel. In this study the effects of SWCNT raw material and purified SWCNT (SWCNT bundles) on cell behaviour of mesothelioma cells (MSTO-211H) and on epithelial cells (A549) had been investigated. The effect on cell behaviour (cell proliferation, cell activity, cytoskeleton organization, apoptosis and cell adhesion) were dependent on cell type, SWCNT quality (purified or not) and SWCNT concentration.
Ionic liquid electrolytes containing a certain amount of bis(fluorosulfonyl)imide (FSI) anion can provide reversible capacity for a graphitized negative electrode without any additives such as a solvent. Cyclic voltammetry for a graphitized negative electrode in ionic liquid electrolytes containing FSI with other anions suggests that the reversibility of Li intercalation correlates with the relative quantity (or concentration) of FSI in the electrolytes, and that the correlative tendency depends on the other kind of anion. On the basis of the present results, we discuss the effect of FSI in the ionic systems on a graphitized electrode interface.
Corrosive (caustic) material ingestion remains a major health issue, particularly in developing countries. The management strategy after corrosive ingestion should be planned according to the signs and symptoms. The management of corrosive ingestion based on endoscopic grading, nothing by mouth, and barium studies should be abandoned. With the new management protocol, esophageal stricture can be predicted with high accuracy using the simple new prognostic DROOL score (≤ 4) rather than endoscopic grading, reduced by immediate oral feeding as soon as the patient can swallow saliva instead of nothing by mouth, diagnosed earlier (10–14 days) by fluoro-endoscopic balloon-assisted esophageal examination for patients with persistent dysphagia instead of relying on a barium study (≥ 21 days), and adequately treated by initiating balloon dilation earlier during the same anesthesia procedure. Fluoroscopically guided balloon dilatation with large balloons (18–20 mm) seems to be safe, with a low frequency of complications and a high success rate. If dilatation fails after a few months, esophagectomy and replacement surgery using the stomach should be considered. The increased risk of developing esophageal carcinoma after ingestion of corrosive substances should be kept in mind.
An analytical model is developed for the discharge voltage of Li–air batteries with mixed organic/aqueous electrolyte and used to analyze the effects of the oxygen dissolution, solubility, pressure, and diffusivity, reaction rates, and internal resistance on the power density of Li–air batteries. By carefully identifying the model parameters using experimental data it is shown that, for discharge currents above 25 mA cm−2 the power of these batteries is mainly limited by the large internal resistance of the membrane and membrane/electrolyte interfaces (which is currently larger than 100 Ω cm2), while for smaller discharge currents the power is limited by the low oxygen concentration at the reaction sites. The maximum power density can be increased by approximately 1.5 times if the internal resistance is decreased from 100 Ω cm2 to 25 Ω cm2. This relatively small increase in the power density is due to the low dissolution rate and solubility of the oxygen in the liquid electrolyte. Finally, when the battery is operated at maximum discharge power, the oxygen diffusion length in the aqueous electrolyte is under 1 μm, which shows that one needs to use partly wet cathodes in order to achieve high power densities in these batteries.
A new approach has been developed for the preparation of anodes for rechargeable Li batteries based on nanoparticles of tin as an alloying medium embedded in microporous (pore diameter, <2nm) carbon matrices. It is assumed that if tin particles are confined within the carbon micropores, they may exhibit better cyclability upon alloying–dealloying with lithium, since the detrimental effect of the volume expansion of Li x Sn upon alloying can be avoided. A volatile compound of tin, SnCl4, was physisorbed to the carbon surface. This was followed by hydrolysis to SnO2 and by high temperature degassing, which completed the hydrolysis and removed any volatile residue. Using SEM, EDAX and XRD analyses, we could show that we indeed obtained porous carbon, with particles of tin oxide within the microporous system. These matrices were tested as negative electrodes for secondary Li batteries. At this early stage of the study, a reversible capacity as high as 305mAhg−1 was obtained (carbon and Sn), which means that the capacity of the Li–tin alloying was not to far from its theoretical value. The next steps in this study are: 1. Increasing the amount of tin that can be included in the carbon matrices. 2. The development of the preceding reduction process of SnO2 to Sn, which will reduce pronouncedly the initial irreversible capacity.
To explore the surface state of electrocatalysts, herein we developed a surface laser modification (pulsed laser ablation, PLA) approach for the fabrication of NiCo2O4-δ with substantial inner oxygen vacancies (Vo ·· ) and higher exterior Ni3+/Ni2+ ratio. The separated NiCo2O4 nanoplates were transformed to cross-linked NiCo2O4-δ nanostructure through PLA strategy. As compare with the primordial NiCo2O4 produce, the laser-modificated NiCo2O4-δ exhibits higher capacitance, lower overpotential and better electrocatalytic performance. The first-principles calculation proves that the additional energy level is introduced between the valence band and conduction band of L-NiCo2O4-δ. The additional energy level not only benefits the hopping of electrons, but also inhibits the recombination of electron-hole pairs. The X-ray photoelectron spectrum (XPS) confirms that the active sites of the electrocatalytic reaction are Vo ·· , suggesting that the electron structure of catalyst could be adjusted by PLA. The high electrocatalytic activity of laser-modificated NiCo2O4-δ could be ascribed to the synergistic effect of increased number of inner Vo ·· , higher electrochemically active surface area, and dominated Nioct. Our findings might inspire new thoughts on the tuning the surface state and electronic structure of electrocatalyst.
A tin–carbon composite synthesized by high energy mechanical milling (HEMM) technique is characterized here as an anode material for lithium ion battery. The composite morphology and structure are studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively, and its electrochemical behavior is characterized by cyclic voltammetry (CV) and galvanostatic cycling in lithium cell. The electrode evidences highly nanostructured morphology and enhanced lithium–tin alloying–de-alloying process stability as the mechanical milling time is increased, with capacity ranging from 500 to 400mAhg−1. Further important characteristic of the tin–carbon nanostructure reported here is the very high rate capability, extending up to 2Ag−1, that finally allows to its application in a high voltage, high rate lithium ion cell using the LiNi0.5Mn1.5O4 spinel cathode. The cell shows a working voltage of 4.3V and a capacity of 120mAhg−1 obtained at 1C rate. The very promising features of the cell, its high energy and power density, and the low cost of the involved materials, suggest that the electrode reported here can be efficiently used as an anode in advanced configuration lithium ion battery.
Lithium-rich layered oxides have being regarded as one of the most promising cathodes for next generation high energy density lithium ion batteries due to their extremely high capacity beyond 250mAhg−1. Among which, Ru-based lithium-rich layered oxides attract special research interests recently for their relatively low irreversible capacity loss during initial cycle and good rate performance. However, as a typical Ru-based lithium-rich layered oxides, Li2RuO3 suffers severely from poor cycling stability and huge voltage decay upon prolonged cycling. Here, we propose a mono-valence cationic substitution strategy of Na+ ions into Li2RuO3 lattice to form Li2-xNaxRuO3 (x=0, 0.02, 0.06, 0.1) series and systematically investigate their electrochemical properties. The results show that Na+ substitution significantly enhance electrochemical performance of Li2RuO3. Specifically, Li1.94Na0.06RuO3 exhibits the best cycling stability, possessing capacity of over 220mAhg−1 after 50 cycles at 1C rate and retaining energy density of 673Whkg−1 after 50 cycles at 0.2C rate. Li1.9Na0.1RuO3 displays the least voltage decay with only 61mV after 50 cycles compared with 228mV for Li2RuO3. The Na-doped Li2RuO3 samples in this work are leading the electrochemical performance of all ever reported Ru-based lithium-rich layered oxides previously, providing a new scope for the strategy to rationally design high-performance lithium-rich layered oxides with balanced cycling stability and voltage maintainance.
The electrochemical behavior of lead, lead–antimony, and lead–calcium–aluminium–tin alloys has been studied in solutions containing various concentrations of sulfuric and phosphoric acids. The dependence of these electrode processes on some experimental conditions (mainly sweep rate and potential range) has been studied. The measurements were performed using a cyclic voltammetry technique. The study and the analysis of the morphology of alloys have been performed using a scanning electron microscope (SEM). Cyclic voltammograms of the lead–antimony alloy electrodes, similarly to pure lead electrode, also show the “anodic excursion” peak under some experimental conditions. Well defined current waves, corresponding to the oxidation and reduction processes of Sb, are observed, if the alloy surface is freshly abraded. The oxidation of antimony starts at potentials at which the formation of PbO takes place. The peak current of Sb oxidation reaction decreases during successive cycles, suggesting that Sb dissolves from the alloy surface during the first CV sweeps. Another explanation for this effect might be the formation of a PbSO4 selective membrane.