batterydata/paper-abstracts huggingface dataset:
Poor electrical conductivity of sulfur, sluggish redox kinetics, dissolution of intermediate polysulfides, and expansion in volume upon cycling are the main drawbacks that hamper the practical application of Li-S batteries. By taking advantages of the high conductivity and favorable catalytic activity of RuO2, we design a 3D carbon nanotube film with embedded RuO2 nanoparticles as a freestanding type of chemisorptive and catalyst-like cathode for Li-S batteries, which can be facilely prepared by a surfactant-assisted vacuum infiltration method. Both experimental and theoretical results reveal the excellent capability of RuO2 for anchoring polysulfides and accelerating the kinetics of polysulfides catalytic redox reactions. Besides, the 3D freestanding cathode is beneficial to overcoming pulverization during volume changes, especially for long-term cycling. At a high areal sulfur loading of 2 mg cm−2, favorable initial capacities of 750 and 1060 mA h g−1 respectively at 2 and 0.5 C are achieved. More attractively, the capacity after 1000 cycles maintains 405 mA h g−1 at 0.5 C with a loss in capacity of only 0.06% per cycle. Additionally, such freestanding cathode allows the batteries to be tested under various bending stages, hence encouraging more research works on fabrication of other 3D nanostructure families as high-performance cathodes for Li-S batteries.
The Lithium-ion batteries (LiBs) are the core component of the all-climate electric vehicles. The aging state recognition is carried out based on the proposed electrochemical model (EM) instead of the traditional equivalent circuit model (ECM) and black boxes model in this paper. Firstly, a group of mathematical equations are built to describe the physical and chemical behaviors of batteries based on the electrochemical theory. Then, the finite analysis method and the numerical computation method are used to solve the mathematical equations and the model has been built. Next, the optimization algorithm is used for identifying the parameters of the model. The aging state recognition of the battery on whole lifetime is carrying out based on the ageing data. Five aging characteristic parameters are determined to describe the health state of the battery, and their degradation trajectories are obtained. Finally, a battery-in-loop approach is employed to verify the model based degradation recognition. Results show that the maximum voltage error is within 50 mV and the state of health estimation error is bounded to 3%.
Intermittent renewable sources provide an ever-greater share of electricity, which changes the variability of the net load. This study models different renewables combinations over different timescales for the Nordic power system and shows how the optimal mix depends on the frequency band of the fluctuations.
A Fe–Si (FeSi2 + Si)/C composite was prepared by mechanical ball milling and investigated as a new inserting anode for use in Li-ion batteries. The composite so prepared has a sandwich structure with the alloy particles as middle cores and the graphite layer as outer shells. The charge-discharge measurements revealed that the Fe–Si/C composite not only had a quite high initial capacity of approximately 680mAhg−1, but also exhibited greatly improved capacity retention with a reversible capacity of approximately 500mAhg−1 after 15 cycles in comparison with pure Si and Fe–Si alloy. Based on XRD, XPS, SEM, Raman and EIS analysis of the composite electrode in different lithiated states, the mechanism for improved cycleability is found to be due to the effective buffering of the volumetric changes of the Fe–Si particles by the graphite shell.
Needless to say, I am especially pleased by the central place of prior knowledge in the studies appearing in this issue. It was nice to see research support for the argument made over many years (Tobias 1973, 1976, 1989, 2003, 2005) that prior knowledge plays a central role in such research. Specifically, the general hypothesis guiding prior ATI studies of interactions between prior knowledge and instructional methods was that students with low prior knowledge needed substantial instructional support to learn effectively, whereas those with high prior knowledge could succeed with limited support [see Tobias (2009) for extended discussions of both instructional support and the advantages of seeking ATIs involving prior knowledge that are beyond the scope of this paper; recommended research designs for ATI studies can be found in Tobias (in press)]. Each of the studies in this issue offers consistent backing for the ATI between prior knowledge and instructional support, whether the support consists of adding iconic representations, metacognitive prompts, guided instruction, adaptive computer tutors, or segregating content to make the material more comprehensible.
This paper presents the direct synthesis of highly nanoporous carbon materials via the carbonization of sodium oxalate in inert atmosphere without any activation. The carbonization temperature and time are very important for the carbon structures and their electrochemical performance in supercapacitors. The SOC–800–2.5 material derived from sodium oxalate has a high specific surface area of 1456 m2 g−1, and a total of 74 % of the pore volume is composed of mesoporosity with average pore size 3.7 nm, which is ideal for adoption as an electrode for supercapacitors. The SOC–800–2.5 material can also deliver a high specific capacitance of 245 F g−1 at a constant charge/discharge current of 0.7 A g−1. This capacitance is maintained at a value of 173 F g−1 at 10 A g−1. This material also has good cycle stability with over 89.1 % capacitance retention after 5000 cycles when measured in a three-electrode system using 6 M KOH as electrolyte.
Lithium–sulfur batteries have the theoretical energy density of up to 2600 Wh/kg, though its commercialization is limited by high material cost and poor cyclic performance. In this work, we show that sepiolite-sulfur is a high-capacity, high-rate performance, and low-cost cathode material for lithium–sulfur batteries. Sepiolite is a porous mineral with specific structure, outstanding physical and chemical adsorption characteristics, and excellent ion exchange capability, making it an ideal matrix material for lithium–sulfur batteries. It is shown that the first specific discharge capacity of sepiolite-sulfur cathode is about 1436 mAh g−1 at 0.2 C current rate, and it remains as high as 901 mAh g−1 after 300 cycles. Under 1 C current density, the first discharge capacity is 1206 mAh g−1, and maintains a high value of 601 mAh g−1 after 500 cycles. The raw materials are abundant and low cost, and the manufacturing process is simple and scalable, making it promising for the commercialization of lithium–sulfur batteries.
Reduced graphene oxide (r-GO) paper is easily synthesized by a flame-induced reduction of graphene oxide (GO) paper under ambient conditions. The X-ray diffraction and X-ray photoelectron spectroscope results confirm the effectivity of the flame-induced reduction. The resulting r-GO paper has a high surface area of 274.9 m2 g−1 and contains a certain amount of oxygen-containing groups. Electrochemical behaviors of the electrode built with the r-GO paper are investigated in two kinds of electrolytes, 2 M KOH aqueous solution and 1 M Et4NBF4-acetonitrile solution, respectively. The results show that the high values of the specific capacitance for the r-GO can be obtained in both electrolytes, which reach 212 and 160 F g−1 at the same current density of 1 A g−1 respectively. Also, the r-GO-based electrode and supercapacitor exhibits stable cycling performance. The good capacitive performances in KOH aqueous electrolyte are due to the high surface area and the remaining oxygen containing groups of the r-GO paper.
The critical challenge of high-capacity Si anodes lies in its volume changes, which breaks the electronic network and induces unstable solid electrolyte interphase (SEI). Herein, take microscale porous Si (PS) for an example, hierarchical Al2O3/multilayer graphene (mG) shells are fabricated to address the above problems. The inner ceramic Al2O3 (1 nm) shell can uniform the volume expansion and confine the PS to the void space. In addition, the outer cross-linked mG not only provides sufficient electronic pathways but also helps to form a uniform and condense SEI. The synergetic advantages of the enhanced mechanical integrity, the robust electronic network, and the stable SEI; enable the electrodes exhibit remarkable cycling stability, a 92% capacity retention of 1716 mAh g−1 at 0.2 A g−1 over 90 cycles and 966 mAh g−1 at 1 A g−1 after 600 cycles. This work provides new insights in addressing the electrode materials with large volume expansions.
Poly(diphenylamine) (PDPA) film was deposited on indium doped tin oxide coated glass electrode in 1 M perchloric acid by cyclic voltammetry. Cyclic voltammograms (CVs) of the PDPA film were recorded with different potential limits and the redox transitions in PDPA were identified. The spectroscopic changes accompanying the redox transitions were followed at different applied potentials using UV–visible spectroscopy. Dynamic cyclic spectrovoltammetry was used to deduce the derivative cyclic voltabsorptogram (DCVA). The absorbance changes are represented by constructing a novel absorbance–potential–wavelength profile. In the profile, the CV showing the redox transitions is presented side by side to identify the electrochromic sites in PDPA in an easy way. The results deduced are compared with the conventional DCVA. Identifying the electrochromic sites brought out the differences in electrochromic behavior between PDPA and PANI.
Membranes are an important part of vanadium redox flow battery cells. Most cell designs use Nafion®-type membranes which are cation exchange membranes. Anion exchange membranes are reported to improve cell performance. A model for a vanadium redox flow battery with an anion exchange membrane is developed. The model is then used to calculate terminal voltages for open circuit and charge–discharge conditions. The results are compared to measured data from a laboratory test cell with 40 cm2 active membrane area. For higher charge and discharge currents, an empirical correction for the terminal voltage is proposed. The model geometry comprises the porous electrodes and the connected pipes, allowing a study of the flow in the entrance region for different state-of-charges.
This work aims at the investigation and optimization of a hybrid start-up process for a self-sustained reactor for n-butane to syngas conversion in intermediate temperature, micro-solid oxide fuel cell (micro-SOFC) power plants. The catalytic reaction is carried out in the presence of Rh-doped Ce0.5Zr0.5O2nanoparticles in a disk-shaped reactor. For the start-up, a resistance heater is embedded inside the catalytic bed and is activated until the exothermic oxidative reaction is initiated. The self-sustained temperature and reforming performance are demonstrated to be highly dependent on the fuel to oxygen (C/O) ratio and the catalytic activity at different space times. It is shown that a C/O ratio of 0.8 is a very good choice in terms of achieved steady-state temperature, syngas selectivity and start-up time. At a reactor inlet temperature of 809 °C for a C/O ratio of 0.8 and a space time as low as 8 ms, a syngas selectivity of 69.6% and a temperature of 529 °C at the simulated micro-SOFC membrane are demonstrated. After only 15 s from ignition, a temperature of 600 °C at the reactor inlet is reached. The hybrid start-up process is optimized with respect to a specific setup as an example, but is of general nature and utility to similar systems.
By investigating three patients with progressive agraphia, we explored the possibility that this entity is an early sign of degenerative dementia. Initially, these patients complained primarily of difficulties writing Kanji (Japanese morphograms) while other language and cognitive impairments were relatively milder. Impairments in writing Kana (Japanese syllabograms), verbal language, executive function, visuo- and visuospatial cognition and memory were identified by neuropsychological testing. The agraphia was compatible with a peripheral type, based on deficits at the interface between the central letter selection and the graphemic motor execution (Patient 1) or at the stage of central letter selection as well (Patients 2 and 3). Agraphia was generally more prominent, although not exclusive, for Kanji probably because of later acquisition and larger total number of Kanji letters leading to lower frequency of use and familiarity per letter. Concurrent or subsequent emergence of non-fluent aphasia, ideomotor apraxia, executive dysfunction and asymmetric akinetic-rigid syndrome in two patients suggested degenerative processes involving the parietal–occipital–temporal regions, basal ganglia and striato-frontal projections. We propose that progressive agraphia may be one of the early symptoms of degenerative dementia such as corticobasal degeneration.
The unprecedented rise in the population of older adults and the number of seniors living with and managing chronic conditions are straining our institutional health care systems leading to reduced care quality and unmanageable cost increases. At the same time, an overwhelming majority of older adults express a strong desire to age in place in their communities. Ambient home sensing presents an opportunity to reduce healthcare costs by facilitating older adults’ ability to age-in-place in more familiar, less restrictive, and less expensive environments. Further, ambient home sensing tools have the potential to extend the health care work force and enhance health care quality/outcomes by facilitating remote patient monitoring as well as early intervention and prevention against adverse events – all while catering to older adults’ preference to live at home. Despite their potential, there is limited research at present about the benefits of ambient sensing systems installed in private homes, and older adults’ response to them. This paper describes a pilot ambient home sensing project, HomeSense, actively deployed in the homes of older adults residing in The Villages, Florida.
A microwave-assisted reflux method was used to rapidly synthesize CoAl-layered double hydroxide (CoAl-LDH)/graphene oxide composite. In the synthetic procedure, graphite oxide (GO) was exfoliated to graphene oxide nanosheets in company with the in situ growth of CoAl-LDH. The as-prepared products showed lamellar structures. The aggregation of LDH was effectively prevented by the presence of graphene oxide nanosheets. Electrochemical performances were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. All the composites had higher rate capability than pure CoAl-LDH, maintaining about 80% of discharge capacitance when the current density increased from 1Ag−1 to 20Ag−1. A maximum specific capacitance of 772Fg−1 was obtained at 1Ag−1 in 6M KOH solution for the composite containing 12.9% GO. Moreover, the composite exhibited excellent long cycle life with about 73% specific capacitance retained at 6Ag−1 after 10,000 cycles.
Among features of motor disorders in children, spasticity is associated with considerable morbidity and problems in care, particularly in severely affected patients. Intrathecal baclofen (ITB) has been increasingly used as a relatively specific treatment modality for spasticity. To date, most of the evidence for its use in paediatric patients has come from retrospective and uncontrolled studies, although randomised, controlled trials of screening ITB and ITB therapy itself have recently been published. This consensus statement on the use of ITB in paediatric patients with spasticity was developed on the basis of currently available evidence, with the aim of providing information for clinicians, promoting an expert opinion and a consistent approach to the management of these patients and emphasising the need for further prospective, large-scale studies.
Hollow nanostructures, owing to their unique structural features, have attracted tremendous attention in electrochemical energy storage and conversion. Herein, we develop a facile and controllable, but rational and effective, method to prepare a highly active hollow nitrogen-doped carbon nanoshell (termed as HNS-800) oxygen reduction electrocatalyst. The hollow nano-shelled catalyst was synthesized by using 9,11,20,22-tetraaza-tetrapyridopentacene (tatpp) as the building block and coated with silica nano-spheres as the template, followed by carbonization at 800 °C and finally chemical etching. The average thickness of the nanoshell is ∼10 nm and about three times improvement in the specific surface area (from 253 to 647 m2 g−1) was obtained owing to the formation of the nanoshell structure. Compared with the traditional solid nanorod structure prepared without the controlled template (termed as NR-800), the newly formed hollow nanoshell structure contributed to the huge promotion of ORR in both alkaline and acidic media. The as-obtained HNS-800 exhibited very efficient activity with a high kinetic current density (Jk) of 18.02 mA cm−2 at 0.8 V vs. RHE and a small Tafel slope of 69 mV dec−1. In particular, the half-wave potential of HNS-800 (0.87 V vs. RHE) was higher by 25 mV than that of the benchmark Pt/C in 0.1 M KOH. Unlike the commercial Pt/C electrode, the HNS-800 electrocatalyst was almost free from the methanol crossover effect and showed a better stability.
During the discharge of SOCl2/Li batteries, the LiCl deposits mainly at the entrance of the widest pores. C/Ni/PTFE cathodes were prepared with 12 varieties of carbon materials. The discharge is strongly depending upon the carbon used. The capacity of the battery is mainly correlated to the pore volume of the cathode. However, for cathodes with a significant pore volume, the capacity is also correlated to the specific surface area.
A novel nano-GeO2/mesoporous carbon (GeO2/MC) composite material was prepared by in-situ decomposition of germanium ethoxide (Ge(OC2H5)4) infiltrated in a mesoporous carbon (MC) obtained by soft-templating procedure. With GeO2 (<20 nm) homogeneously distributed in the carbon network, the GeO2/MC composite retains 93% of its initial charge capacity after 380 cycles at constant 1 C rate (1500 mA g−1) as electrode material vs. Li and shows high rate capability at variable current rates. A restructuration of the germanium phase into smaller particles during the first cycles is also evidenced. The composite presents a set of advantages such as low GeO2 content, convenient preparation approach and high coulombic efficiency (>99%).
Transmitters used in telemetry studies are typically surgically implanted into the coelom of fish. When large numbers of fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools (such as scalpels, forceps, needle holders and sutures) to be sterilized or, at minimum, disinfected between each use to minimize the transfer of pathogens. Chemicals are commonly used for disinfection but they can potentially harm fish and surgeons. UV radiation could provide a safe and more effective means for disinfection. The efficacy of UV radiation was determined for disinfecting surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. The organisms include Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, the causative agents of ulcer disease, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively.
An ionic liquid electrolyte containing bis(fluorosulfonyl)imide (FSI) anion without any solvent is applied to a silicon–nickel–carbon (Si–Ni–carbon) composite anode for rechargeable lithium (Li)-ion batteries. The FSI-based ionic liquid electrolyte successfully provides a stable, reversible capacity for the Si–Ni–carbon anode, which is comparable to the performance observed in a typical commercialized solvent-based electrolyte, while a common ionic liquid electrolyte containing bis(trifluoromethanesulfonyl)imide (TFSI) anion without FSI presents no reversible capacity to the anode at all. Ac impedance analysis reveals that the FSI-based electrolyte provides very low interfacial and charge-transfer resistances at the Si-based composite anode, even when compared to the corresponding resistances observed in a typical solvent-based electrolyte. Galvanostatic cycling of the Si-based composite anode in the FSI-based electrolyte with a charge limitation of 800mAhg−1 is stable and provides a discharge capacity of 790mAhg−1 at the 50th cycle, corresponding to a cycle efficiency of 98.8%.
Nickel-iron (Ni-Fe) rechargeable batteries are attractive as sustainable solutions for large-scale electrical energy storage because of their low cost, eco-friendliness and safety, but their iron anodes always suffer from low capacity and poor stability, which greatly limits their wide applications. We present here a molecular confinement strategy to fabricate ultrasmall iron oxide nanocrystals firmly mounted on carbon (mc-FeOx/C) that works as stable anode material for high energy density Ni-Fe batteries. Compared with conventional iron oxide on carbon synthesized without molecular confinement (FeOx/C), the mc-FeOx/C exhibits a much higher capacity (370.2 vs 159.5mAhg−1 at a current density of 2Ag−1) and better stability (capacity retention of 93.5% vs 61.2% after 1000 charge/discharge cycles). When to further combine with a nickel cathode, the mc-FeOx/C based Ni-Fe battery delivers an energy density up to 173.7Whkg−1, among the highest value for Ni-Fe batteries reported so far. The mc-FeOx/C based Ni-Fe battery also offers excellent rate capability (e.g., 112.6Whkg−1 at 28.9kWkg−1) and good stability (capacity retention of 91.6% after 1000 cycles), retaining their applications for large-scale electrical energy storage.
Polyether glycosidic ionophores and macrocyclic glycosides are of great interest, especially for the medicinal and pharmaceutical industries. These biologically active natural surfactants are good prospects for the future chemical preparation of compounds useful as antibiotics, anticancer agents, or in industry. More than 300 interesting and unusual natural surfactants are described in this review article, including their chemical structures and biological activities.
A polyaniline (PANi)/PANi-grafted multiwalled carbon nanotube (PANi/PANi-g-MWCNT) mixture was prepared by simple suspension (dynamic interfacial) polymerization. Scanning electron microscopy showed a two-phase mixture of PANi and PANi-g-MWCNTs while transmission electron microscopy of PANi-g-MWCNT showed a core–shell structure with outer PANi layer (5–10nm). Depending on the doping level, estimated by relative carbon content, the electrical conductivity of PANi/PANi-g-MWCNT was improved by more than four orders of magnitude over that of PANi. The composite also displayed high electrochemical activity with improved stability in an oxygen-saturated acidic solution.