batterydata/paper-abstracts huggingface dataset:
Mixed alkyl carbonates are widely used as solvent for a various lithium-ion battery applications. Understanding the behavior of each solvent in the mixed system is crucial for controlling the electrolyte composition. In this paper, we report a systematic electrochemical and spectroscopic comparison of the reduction of propylene carbonate (PC), ethylene carbonate (EC), and diethyl carbonate (DEC) when used as single (PC), binary (EC/PC, EC/DEC), and ternary (EC/PC/DEC) solvent systems. The reduction products are identified based on Fourier transform infrared spectroscopy (FTIR) after employing linear sweep voltammetry to certain potential regions and their possible formation mechanisms are discussed. FTIR analyses revealed that the reduction of EC and PC was not considerably influenced by the presence of other alkyl carbonates. However, DEC exhibited a different reduction product when used in EC/DEC and EC/PC/DEC solvent systems. The reduction of EC occurred before that of PC and DEC and produced a passivating surface film that prevented carbon exfoliation caused by PC. Battery performance test, cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscope is employed to study the surface films formed. The binary EC/DEC solvent system demonstrated more favorable performance, smaller impedance, and higher Li+ ion diffusivity than did the other solvent systems used in this study.
Current Chinese policy promotes the development of both electricity-propelled vehicles and carbon-free sources of power. Concern has been expressed that electric vehicles on average may emit more CO2 and conventional pollutants in China. Here, we explore the environmental implications of investments in different types of electric vehicle (public buses, taxis and private light-duty vehicles) and different modes (fast or slow) for charging under a range of different wind penetration levels. To do this, we take Beijing in 2020 as a case study and employ hourly simulation of vehicle charging behaviour and power system operation. Assuming the slow-charging option, we find that investments in electric private light-duty vehicles can result in an effective reduction in the emission of CO2 at several levels of wind penetration. The fast-charging option, however, is counter-productive. Electrifying buses and taxis offers the most effective option to reduce emissions of NOx, a major precursor for air pollution.
LiCoO2 thin films were synthesized by sol/gel process using acrylic acid (AA) as chelating agent. The gel formulation was optimized by varying solvent (ethylene glycol or water) and precursors molar ratios (Li, Co, AA) in order to obtain a dense film for positive electrode of lithium batteries. The gel was deposited by spin-coating technique on an Au/TiO2/SiN/SiO2/Si substrate. Thin films were deposited by either single or multistep process to enhance the density of the thin film and then calcined during 5h at 800°C to obtain the R-3m phase (HT-LiCoO2). A chemical characterization of the solution was realized by Fourier Transform Infrared (FTIR) spectroscopy. Thermal decomposition of precursors and gel was studied by Thermo Gravimetric Analyses (TGA). Further investigations were done to characterize rheologic behaviour of the gel and solvents affinity with the substrate. Crystallinity and morphology were analyzed respectively by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The formation of R-3m phase was confirmed by the electrochemical behaviour of the gel derived LiCoO2. Cyclic voltammograms and galvanostatic cycling show typical curve shape of the HT-LiCoO2.
Lithium ion dynamics in Li4+x Ti5O12 spinel are investigated from first principles calculations. The diffusion pathways are optimized and the energy barriers of lithium migration under four types of dilute defect extremes: Li4+δ Ti5O12, Li4−δ Ti5O12, Li7+δ Ti5O12 and Li7−δ Ti5O12 (δ ≪1) are calculated with the nudged elastic band method. Results show that lithium diffusion in the charged state (energy barriers are 1.0 and 0.7eV for interstitial Li and Li vacancy diffusion, respectively) is much slower than in the discharged state (energy barriers are 0.13 and 0.35eV for interstitial Li and Li vacancy diffusion, respectively). The diffusion coefficients are evaluated based on lattice gas model and hopping mechanism. The obtained results are compared with available experimental data within a two-phase co-existence framework.
Cognitive impairment is a major sequela after stroke. A recent study shows that cognitive impairment is prevalent after ischaemic stroke, even in patients with good functional recovery, and that compromise in different cognitive domains predicts future functional disability. Here, we reflect on how poststroke cognitive impairment is measured and conceptualized.
Why are genetic technologies necessary in the agri-food sector and why have they created such opposition in the rural domain? The paper attempts to place GM in its contested regulatory context, situated as part of three different and competing paradigms of agri-food and rural development: the agri-industrial, post-productivist and rural development models. Conceptually, it is argued that GM is currently positioned as a relatively new variant and component of the mutating and dominant agri-industrial paradigm. This sets the context and development of GM at a global level. The paper explores in its first part how the spread of GM relates to the maintenance of the unsustainable. Whilst this remains a driving force we see, in the second part, with reference to the unfolding nature of European regulation since 2000, the ways in which this agri-industrial imperative is shaped by particular State actions which blend this agri-industrial model with a wider set of consumer, private sector and environmental concerns. Overall, the EU has managed to translate a global agri-industrial imperative, despite significant external pressure, into a highly regulated ‘post-productionist’ framework in which both private and public interests are given responsibility for delivering consumer rights. This may, or may not allow room for rural sustainable development alternatives to take hold. At least it provides something of an opportunity.
Thermo-set membranes prepared by free-radical photo-polymerisation (UV-curing) could be an interesting alternative to the existing Li-ion battery polymer electrolytes. UV-curing takes place at room temperature and it is based on initiating a chemical polymerisation inside a liquid poly-functional monomer, containing a proper photo-initiator, using direct UV-irradiation to create a highly cross-linked solid film. The present communication illustrates the results obtained from the investigation of a class of polymeric networks prepared by incorporating siloxane-based monomers into a methacrylic-based polymer matrix. The gel-copolymer membranes were obtained in the form of flexible, easy to handle, translucent films by UV-irradiation of a mixture of monomers in the presence of a radical photo-initiator with the in-situ addition of an EC/DEC solution. The polymer electrolyte was prepared by swelling the obtained membrane in a LiTFSI-EC-DEC solution. The chemical and structural properties were characterised by real-time FT-IR, TGA, DSC, and their surface characteristics were assessed by dynamic contact-angle measurements. Electrochemical tests on ionic conductivity, stability and cyclability in lithium cells pointed out the importance of the co-polymerisation in the presence of siloxane acrylates which improved the interfacial properties of the gel-copolymer membranes. Good values of ionic conductivity were obtained even at ambient temperature.
The use of anion-inserting organic electrode materials represents an interesting opportunity for developing ‘metal-free’ rechargeable batteries. Recently, crystallized conjugated diamines have emerged as new host materials able to accommodate anions upon oxidation at potentials higher than 3 V vs. Li+/Li0 in carbonate-based battery electrolytes. To further investigate the electrochemical behavior of such promising systems, comparison with electroanalytical data of soluble forms of conjugated diamines measured in battery grade electrolytes appeared quite useful. However, the literature on the topic is generally poor since such electrolyte media are not common in molecular electrochemistry. This contribution aims at providing relevant data on the characterization by cyclic voltammetry of unsubstituted, diphenyl-substituted and tetramethyl-substituted p-phenylenediamines. Basically, these three molecules revealed two reversible one-electron reaction upon oxidation corresponding to the electrogenerated radical cation and dication, respectively, combined with the association of electrolyte anions (i.e., PF6 −, ClO4 − and TfO−). The nature of the counter-anion did not show much influence on the electrochemical activity, which remained governed by the solvation process in high-polarity solvents (i.e., PC- or EC-based battery electrolytes). However, in presence of PF6 −, the emergence of a pre-peak prior to the second oxidation step was observed when labile protons exist in the radical cation state. This contribution is attributed to a deprotonation reaction of the radical cation induced by the catalytic decomposition of PF6 − in presence of H+, which supports well the few other experimental data reported on the decomposition issues of LiPF6. In addition, substitution of the amine redox centers with appropriate functional groups (that increase the molecule π-delocalization) allowed to reach higher formal potentials without impacting the bi-electronic behavior and the reversibility of the processes.
Survivors of allogeneic hematopoietic stem cell transplantation (alloHCT) may experience cognitive impairment over time post-treatment, but early identification of these individuals is limited.
Sections of Na–Al–NiCl2 cathodes from sodium-beta alumina ZEBRA batteries have been characterized with X-ray fluorescence mapping, and XANES measurements to probe the microstructure, elemental correlation, and chemical speciation after voltage cycling. Cycling was performed under identical load conditions at either 240 or 280 °C operating temperature and subsequently quenched in either the charged or discharged state. X-ray fluorescence mapping and XANES measurements were made adjacent to the current collector and β″-Al2O3 solid electrolyte interfaces to detect possible gradients in chemical properties across the cathode. An FeS additive, introduced during battery synthesis, was found to be present as either Fe metal or an Fe(II) chloride in all cathode samples. X-ray fluorescence mapping reveals an operating temperature and charge-state dependent spatial correlation between Fe, Ni, and Cl concentration. XANES measurements indicate that both Ni and Fe are chemically reactive and shift between metallic and chloride phases in the charged and discharged states, respectively. However the percentage of chemically active Ni and Fe is significantly less in the cell operated at lower temperature. Additionally, the cathode appeared chemically homogeneous at the scale of our X-ray measurements.
Objective To clarify the cognitive profiles including visuo-spatial abilities and social cognition of patients with Kabuki syndrome (KS). Methods Cognitive functions of seven KS patients (8.8±2.1 years, 3 girls), all of whom were confirmed as having KMT2D gene mutation (Out of 7 changes, 3 were nonsense mutations, 1 was frameshift deletion, 1 was splice-site mutation, and 2 were missense changes), were investigated using the Kaufmann assessment battery for children test (K-ABC), with copying tasks of 2D and 3D line figures. We also performed Theory of Mind (ToM) Test (Sally and Anne task). Results The findings from the K-ABC indicated disparities among cognitive areas in the KS participants (p<0.01). Post hoc test (Shaffer's Modified Sequentially Rejective Bonferroni Procedure) revealed that the standard score of the subtest of number recall was significantly higher than those of gestalt closure, triangles and matrix analogies, respectively. In addition, the scores of simultaneous processing scales tended to be lower than those of sequential processing in all the participants and significantly lower in five of the seven participants. The subtests with significantly lower scores than that of the subtest number recall were all grouped into sequential processing. Copying tasks showed the visuo-spatial difficulties often found in patients with Williams syndrome (WS), which is known to have visuo-spatial difficulties. Five out of the seven participants passed the ToM test. Conclusion The K-ABC test revealed significant disparities among the subtests in patients with Kabuki syndrome with the KMT2D gene mutation. They were worse at simultaneous processing tasks and showed visuo-spatial difficulties similar to those of WS patients. Clarifying the characteristic traits of cognitive functions of KS patients may help us to better understand the syndrome.
This study focused on the composition dependence of the crystal structure and cathode performance of xLi(Li1/3Mn2/3)O2–(1 − x)Li(Mn1/3Ni1/3Co1/3)O2 (0 ≤ x ≤ 1) prepared by co-precipitation. From charge-discharge tests, it was found that there was large differences in the battery performance between the composition of x = 0.2 and x ≥ 0.3. For the samples, the average crystal structures were determined by the Rietveld refinement of neutron diffraction patterns. The results indicated that for x = 0.2, Li existed at both 2b and 4g sites, whereas for x ≥ 0.3, Li was localized at 2b sites and Mn occupied the 4g sites. In order to examine the local crystal structure, pair distribution function (PDF) and extended X-ray absorption fine structure (EXAFS) analyses were carried out. From the PDF analysis, a significant difference was seen in the short-range peaks associated with the transition metal layer for x = 0.2, 0.4 and 0.6. The EXAFS results indicated a large difference in the local structure around Mn for x = 0.2 and x ≥ 0.3. This is thought to be due to ordering of LiMn6 and LiMn5Ni, which is likely to affect cathode performance.
Observation of care at birth is challenging with multiple, rapid and potentially concurrent events occurring for mother, newborn and placenta. Design of electronic data (E-data) collection needs to account for these challenges. The Every Newborn Birth Indicators Research Tracking in Hospitals (EN-BIRTH) was an observational study to assess measurement of indicators for priority maternal and newborn interventions and took place in five hospitals in Bangladesh, Nepal and Tanzania (July 2017–July 2018). E-data tools were required to capture individually-linked, timed observation of care, data extraction from hospital register-records or case-notes, and exit-survey data from women.
Intravenous thrombolysis has become a standard practice in eligible patients with acute ischemic stroke (AIS). Functional outcome after AIS is a major concern for patients, families, and neurologists. Identifying factors affecting the early functional outcome and the effect of IV rTPA in Egyptian AIS patients is crucial to address concerns and queries.
The discharge capacity of LiCoPO4, prepared using carbon-containing precursors, heated under different oxygen partial pressures (high-purity argon, air, pure oxygen) was investigated. LiCoPO4 heat-treated under high-purity argon showed a higher discharge capacity over the entire cycle life compared to under air or pure oxygen. No difference in the discharge capacity of LiCoPO4 heat-treated under air or pure oxygen was exhibited. The enhanced discharge capacity of LiCoPO4 heat-treated under argon compared to air/oxygen was a result of its higher electrical conductivity and smaller particle size. The higher electrical conductivity and smaller particle of LiCoPO4 heat-treated under argon is likely do the presence of cobalt phosphides and increased carbon content.
Evidence from neurologically normal subjects suggests that repetition priming (RP) is independent of semantic processing. Therefore, we may expect patients with a selective deficit to conceptual knowledge to exhibit RP for words regardless of the integrity of their semantic representations. We tested six patients with semantic dementia (SD) on a lexical decision task that incorporated four different lags between first (baseline) and second (primed) presentation of repeated words. The patients exhibited significant RP that was greater for words that were categorised as semantically ‘degraded’ than for words categorised as ‘known.’ This RP advantage for semantically degraded words declined as lag increased. The patients also demonstrated hyperpriming, and a significant correlation was identified between baseline response time and RP in SD but not in controls. These findings indicate that level of semantic knowledge about a word influences both baseline lexical decision performance and RP of that word. The observed hyperpriming can be parsimoniously explained by a cognitive slowing account.
Ambient-temperature ionic liquids (IL) based on bis(fluorosulfonyl)imide (FSI) as anion and 1-ethyl-3-methyleimidazolium (EMI) or N-methyl-N-propylpyrrolidinium (Py13) as cations have been investigated with natural graphite anode and LiFePO4 cathode in lithium cells. The electrochemical performance was compared to the conventional solvent EC/DEC with 1M LiPF6 or 1M LiFSI. The ionic liquid showed lower first coulombic efficiency (CE) at 80% compared to EC–DEC at 93%. The impedance spectroscopy measurements showed higher resistance of the diffusion part and it increases in the following order: EC–DEC–LiFSI<EC–DEC–LiPF6 <Py13(FSI)–LiFSIE=MI(FSI)–LiFSI. On the cathode side, the lower reversible capacity at 143mAhg−1 was obtained with Py13(FSI)–LiFSI; however, a comparable reversible capacity was found in EC–DEC and EMI(FSI)–LiFSI. The high viscosity of the ionic liquids suggests that different conditions such as vacuum and 60°C are needed to improve impregnation of IL in the electrodes. With these conditions, the reversible capacity improved to 160mAhg−1 at C/24. The high-rate capability of LiFePO4 was evaluated in polymer–IL and compared to the pure IL cells. The reversible capacity at C/10 decreased from 155 to only 126mAhg−1 when the polymer was present.
Aging is associated with progressive decreases in aerobic power, thermoregulation, reaction speed and acuity of the special senses. These changes can reduce productivity, particularly in self-paced activities where the physical or mental input of the individual worker is the rate-limiting step in production. Many potential problems can be corrected by worksite modification, employee wellness programmes and retraining. Given wide interindividual differences in the abilities of elderly employees, and the fallibility of most test methods, the setting of appropriate and non-discriminatory standards for recruitment and continued employment of older individuals remains a difficult challenge for the industrial ergonomist. The social need for ever-increasing production also requires critical examination. Relevance to industry A progressive aging of working populations in the industrial nations poses important practical questions concerning the impact of these changes on productivity. What measures can be taken to extend the span of working life, and what is the best method of determining the age when retirement should occur?
A high pressure and temperature based solvothermal route was developed for the synthesis of Fe3O4 with carbon as a composite anode for lithium-ion batteries (LIBs). The carbon in products was a result of the in situ carbonization of organic components under high pressure (24.0MPa) and temperature (350°C). Composites with different amounts of carbon were prepared by annealing the solvothermal products at different temperatures. Taking advantage of the high theoretical capacity of Fe3O4 and favorable characteristics of carbon, a capacity of ~610mAhg−1 after 100 cycles was achieved for the composite with ~54.6% carbon. The carbon amount depended electrochemical performance was also investigated. The Fe3O4@C composite can be used as an alternative anode material and the introduced synthetic strategy may provide further insights into the preparation of inorganic oxides coupled with carbon via in situ carbonization of organic components.
Renewable energy sources have a key role to play in the global energy mix as a means of reducing the impact of energy production on climate change. Wind energy is the most developed of all renewable energy technologies with more than 200 GW of globally installed capacity as of 2011. Analyses of wind farm maintenance costs show that up to 40% of the outlay is related to unexpected component failures that lead to costly unscheduled amendments. Wind farm operators are constantly looking for new technological developments in condition monitoring that can contribute to the minimisation of wind turbine maintenance expenditure. Early fault detection through condition monitoring can help prevent major breakdowns as well as significantly decrease associated costs. Moreover it enables the optimisation of maintenance schedules, reduces downtime, increases asset availability and enhances safety and operational reliability. Faults in the braking system are of particularly concern since they can result in catastrophic failure of the wind turbine. The present study investigates online condition monitoring based on voltages and currents for mechanical wind turbine brake system fault diagnosis.
Ant-nest nanostructured α-Fe2O3 films with a thickness of 10 μm are anodically grown on stainless steel without any binder, and the resulting material functioned as a current collector in the negative electrode of Li-ion batteries. Phase of Fe2O3 in the structure is the key factor determining the battery performance for a high capacity and cyclability. For example, single anodization allows Fe to be dissolved faster than other components such as Cr, resulting in a high Cr ratio in the stainless steel, which deteriorates the retention of the battery capacity during cycling. On the other hand, the Fe–Cr–Ni ratio is not significantly changed if a proper pretreatment for activation, which is able to dissolve all components with a similar dissolution rate in the subsequent anodization step, is performed. The anodic ant-nest nanostructures play a vital role in not only the pathway of Li ions but also releasing the stress of volume expansion during Li insertion/extraction. The optimized electrode delivers a high reversible capacity of 737 μAh cm−2 (737 mAh cm−3 or 1157 mAh g−1) at a current density of 650 μA cm−2 (1 C-rate) and sustains up to 500 cycles with only 0.13% capacity fading per cycle.