batterydata/paper-abstracts huggingface dataset:
The ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) is selected as plasticizer to prepare a series of novel gel polymer electrolytes due to its non-volatility and inflammability. The micro-porous matrix employed in this study is poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methyl methacrylate) (PVDF-HFP/PMMA) membrane synthesized via phase inversion. The effect of the ratio of PVDF-HFP to PMMA on the properties of the micro-porous membrane, such as morphology, porosity and the liquid uptake capability are systematically studied. Thermal and electrochemical properties of the resulting gel polymer electrolyte are also studied with the objective to optimize the quality of the micro-porous gel polymer electrolyte. The results indicate that the micro-porous gel polymer electrolyte MIL-60, derived from the matrix of PMMA-60 (40 wt% PVDF-HFP and 60 wt% of PMMA), presents the lowest glass transition temperature and exhibits the highest ionic conductivity. The LiFePO4/MIL-60/Li coin-typed cell cycled at 0.1C shows the 1st discharge capacity up to 157 mAh·g−1, and remains 151 mAh·g−1 on the 50th cycle.
Electrochemical method for recovering cobalt and manganese from electrode materials of spent lithium ion batteries was studied. Electrochemical leaching of cobalt and manganese from electrode material was optimized by varying different process parameters such as time, acid concentration and current density. Both cobalt and manganese could effectively be leached out at a current density of 400A/m2 in 3h using 2M sulphuric acid. In the subsequent study, the metallic cobalt and electrolytic manganese dioxides was recovered from the leach liquor at 200A/m2, pH 2–2.5 and 90°C after removing aluminum. The commercial feasibility of the study was tested in pilot scale. Overall recovery of Co, Cu and Mn was above 96%, 97% and 99%, respectively.
During the charging of a Zn/Br redox flow battery, cyclic voltammetry and electrochemical impedance spectroscopy measurements were carried out in-situ. As the state of charge (SOC) increased, some polybromide complex accumulated on the Br-side electrode surface and showed a positive effect on the adsorption of bromide ion as well as bromine. The deposition of polybromide complex onto the electrode surface was identified by SEM, EDS, and Raman spectroscopy. As a result, the charge transfer resistance for bromine oxidation decreased from 2.13 ohm to 1.27 ohm as the SOC increased from 0.0% to 80.0%. This may be due to the amphiphilic characteristics of the polybromide complex. While the solution resistance for catholyte was independent of the SOC, that for anolyte sharply decreased with increasing SOC. This could be explained by the increase in zinc ion mobility and the anolyte thickness reduction by growth of zinc metal dendrites.
PURPOSE: To determine whether basal laminar drusen differ in their location, ultrastructure, or composition from drusen associated with aging and age-related macular degeneration. METHODS: A paraffin-embedded block from an eye of a patient with basal laminar drusen was obtained. Sections were examined immunohistochemically using a battery of antibodies and lectins directed against drusen-associated proteins and glycoconjugates, respectively. Thin sections were examined by electron microscopy and compared with eyes with age-related macular degeneration. RESULTS: Drusen in the eye with basal laminar drusen are located between the basal lamina of the retinal pigment epithelium and the inner collagenous layer of Bruch membrane, just as they are in age-related macular degeneration. Two distinct ultrastructural phenotypes are observed in the eye with basal laminar drusen; their substructure is indistinguishable from drusen phenotypes in age-related macular degeneration. Both basal laminar drusen and drusen associated with age-related macular degeneration are bound by the lectins Ricinis communis agglutinin and Arachis hypogea agglutinin (after neuraminidase digestion) and by antivitronectin, anti–HLA-DR, anti–serum amyloid P, and anti-C5 antibodies, but not by antibodies directed against basement membrane–associated heparan sulfate proteoglycan, laminin, fibrinogen, or collagen type IV. CONCLUSIONS: These data support the notion that cuticular or basal laminar drusen are similar to, and perhaps indistinguishable from, drusen associated with age-related macular degeneration and are not nodular or diffuse thickenings of Bruch membrane, as previously suggested. Thus, we suggest basal laminar drusen is a misnomer. This clinical phenotype should be identified as “early adult onset, grouped drusen” or by the eponym “Gass syndrome.” Features of basal laminar drusen, such as uniform drusen size, clustered distribution, and angiographic features, do not appear to be related to differences in drusen location, composition, or substructure.
Anion-doping strategy represents one efficient route to adjust the structure of electrode material for advanced reversible batteries. The work herein obtains an optimized F-doping sodium manganese oxide Na0.44MnO1.93F0.07 with a layer-tunnel hybrid structure, and the essential factors such as synthesis temperature and crystal structure which determine the electrochemical behavior for the F-doping cathode materials are systematically explored and investigated. The optimized cathode Na0.44MnO1.93F0.07 prepared at 900 °C for 3 h, among various Na0.44MnO2−xFx samples, delivers an extraordinary discharge capacity of 149 mA h g−1 and 138 mA h g−1 at 0.5 C and 1 C, respectively. In addition, the electrode displays an impressive cycling stability with a superb capacity retention rate of approximately 79% over 400 cycles at 5 C. And thus, it shows enhanced reversible capacity over the tunnel phase Na0.44MnO2. Therefore, this work provides a new avenue for designing and optimizing the advanced cathode materials with superior electrochemical performance for sodium-ion batteries by introducing halogen anions to modify the structure.
Children as old as 5 or 6years display selective difficulties in revising initial interpretive commitments, as indicated by both online and offline measures of sentence comprehension. It is likely, however, that individual children differ in how well they can recover from misinterpretations and in the age at which they become adult-like in these abilities. To better understand the cognitive functions that support sentence processing and revision, the current work investigated how individual differences in children’s ability to interpret temporarily ambiguous sentences relate to individual differences in other linguistic and domain-general cognitive abilities. Children were tested over 2days on a battery of executive function, working memory, and language comprehension tasks. Performance on these tasks was then used to predict online and offline measures of children’s ability to revise initial misinterpretations of temporarily ambiguous sentences. We found two measures of children’s cognitive flexibility to be related to their ambiguity resolution abilities. These results provide converging evidence for the hypothesis that the ability to revise initial interpretive commitments is supported by domain-general executive function abilities, which are highly variable and not fully developed in children.
Reversible solid oxide cells (SOCs) are potentially useful for electrical energy storage due to their good storage scalability, but have not been seriously considered due to concerns over round-trip efficiency. Here we propose an SOC storage chemistry where the fuel cycles between H2O–CO2-rich and CH4–H2-rich gases. The unique feature is the formation of CH4 during electrolysis, a less endothermic process than the usual H2- or CO-forming reactions, enabling improved efficiency. Thermodynamic calculations and preliminary experiments show that the CH4-rich storage chemistry is produced during SOC operation at reduced temperature (∼600 °C) and/or increased pressure (∼10 atm). Balance of plant storage system requirements are discussed briefly.
(La, Ce, Pr, Nd)2MgNi9 hydrogen storage alloys were prepared through induction melting followed by a long annealing treatment. The structure and electrochemical properties of annealed alloys have been investigated by orthogonal design experiments. Both the individual effects of each substituting element and their interaction in alloys were studied systemically. It has been shown that the structure of main phase in alloys belongs to PuNi3-type with a space group R-3m. Substituting rare-earth elements have a significant effect on both the phase structure of alloys and microstructure. The anisotropic change in the crystal structure of alloys can cause the acceleration of pulverization of alloy particles and result in the deterioration of the cyclic stability of alloy electrodes. Misch metals can raise the plateau pressure of hydrogen absorption/desorption. The discharge capacity of alloy ranges from 342.97 to 380.68mAhg−1 depending on the sort and content of substituting elements. Both cerium and neodymium can obviously reduce the discharge capacity of alloy electrodes. When compared to the La2MgNi9 alloy electrode, mish metals can significantly improve the high rate dischargeability of alloy electrodes. The improvement of the kinetic characteristic of alloy electrodes mainly results from the increase of the hydrogen diffusion rate in alloy bulk.
The lithium insertion chemistry of an iron phosphate with the lipscombite structure, Fe1.19PO4F0.11(OH)0.46(H2O)0.43, was investigated by X-ray diffraction (XRD), galvanostatic cycling, and potentiostatic intermittent titration. The compound, prepared by a simple hydrothermal method, contains interconnecting chains of face-sharing FeO6 octahedra with about 60% Fe occupancy. Assuming that all the iron may be reduced, the theoretical capacity is about 180mAhg−1, similar to that of olivine-type LiFePO4. Reversible intercalation was found to proceed via a single-phase reaction at an average potential of 2.8V versus Li+/Li. Good structural stability upon intercalation/deintercalation was observed. The unit cell volume increased linearly and isotropically with increasing lithium content, reaching 10% for a Li:Fe ratio of 0.96. XRD peak widths increased on lithiation, presumably due to disorder created by conversion of Fe3+ to the larger Fe2+, but decreased on subsequent delithiation. The rate capability of this material appears to be diffusion-limited, and may benefit from a decrease in particle size. The lithium insertion behavior of a related compound, Ti5O4(PO4)4, was also investigated.
The cathodic and anodic stabilities of room-temperature ionic liquids (ILs) are important factors in their applications in electrochemical devices. In this work, we investigated the electron affinities of cations and ionization energies of anions for ionic liquids by density functional theory (DFT) calculations at the B3LYP/6-311+G(2d,p)//B3LYP/6-31+G(d) level. Over 200 unique cations and anions, formed from a set of six base cation structures, three base anion structures, and seven functional groups, were investigated. We find the trends in calculated EAs of alkylated cations and IEs of alkylated anions to be in good agreement with observed experimental trends in relative cathodic and anodic stabilities of various ILs. In addition, we also investigated the effect that functional group substitution at distinct positions in the ions have on the EA of the 1,2,3-trimethylimidazolium cation and the IE of the PF5CF3 anion. The overall impact on the EA or IE can be explained by the known electron-donating and electron-withdrawing inductive and resonance effects of the attached functional group, and the relative strength of the effect depends on the substitution position.
Nanocrystalline LiAl0.1Cu0.1Mn1.8O4 particles were prepared by the ultrasonic spray pyrolysis using nitrate salts at 800°C in air atmosphere. The effects of ultrasonic frequency (120kHz and 2.4MHz) of the atomizer on the particle properties were investigated by X-ray diffraction, scanning and transmission electron microscopy, and energy dispersive spectroscopy. In addition, cyclic voltammetry and galvanostatic tests were performed to study the influence of the particle structure on the electrochemical behavior in Li-ion battery half-cell. Particle characterization studies reveal that the LiAl0.1Cu0.1Mn1.8O4 particles have a nanocrystalline spinel structure. The secondary particles have a spherical morphology and the average particle size of the samples decreases with increase in frequency from 3.5μm to 770nm. Both samples have porous and partly hollow structure. The initial discharge capacities of LiAl0.1Cu0.1Mn1.8O4 particles produced using 120kHz and 2.4MHz atomizers are 82 and 75mAh·g−1, respectively, between 3.0 and 4.8V at 0.1C rate. Discharge capacities at the 4V potential region drop to 85% of the initial values for both samples after 110cycles. Although the micron-sized LiAl0.1Cu0.1Mn1.8O4 particles exhibit higher capacity at 0.1C than the finer particles, the cathode prepared from the submicron particles has a better rate capability with a retention of the discharge capacity that is 3 times higher at 4C rate.
Iron molybdate thin films are studied here as a possible electrode material for future Li and Na microbatteries working in a lower potential range than currently used systems. Monoclinic Fe2(MoO4)3 thin films are successfully deposited using radio frequency (RF) sputtering and an annealing treatment. The electrochemical behaviour of the obtained electrodes against Li and Na is then studied in a coin cell configuration with liquid electrolytes. The redox processes ruling the insertion/deinsertion of Li+ and Na+ are investigated by means of XPS (X-ray Photoelectron Spectroscopy). The results highlight a different behaviour depending on the alkali, with a better redox reversibility for sodium at the end of the first charge. For subsequent cycles however, improved capacity retention is evidenced for cycling versus lithium as compared to sodium which was attributed to the properties of the SEI layer.
Although great accomplishments of functional material synthesis have been achieved in sodium ion batteries (SIBs) recently, there are still numerous challenges and problems in preparing carbon-based materials with porous architectures and enough lattice distance for Na+ insertion. Herein we report a templated strategy to synthesize 3D porous graphene girds (PGGs) consisting of several stacking graphene structure with ultrahigh surface area and hierarchical connected structure by employing Ag nanoparticles (NPs). The Ag NPs will regenerate for decreasing the experimental cost, also in line with principles of green chemistry and environmentally friendly strategy. The PGGs obtain advanced specific capacity of 160 mA h g−1 at current density of 50 mA h g−1. Moreover, 112 mA h g−1 capacity can be gained at 1 A h g−1 during 1000 cycles. Due to their porous architecture, ultrahigh surface area and low amorphous graphited structure, PGGs electrode showed the excellent electrochemical performance in high rate capability.
A comparative study of the heat dissipated by a 3.3Ah Li x C/LiNiO2 cell and a 1.25Ah Li x C/75% LiCoO2, 25% LiNiO2 cell was conducted through experimental heat rate measurements using a radiative calorimeter. The specific heat of the cell was determined experimentally to be 0.969J/°Cg for the LiNiO2 cell and 0.946J/°Cg for the Li x C/75% LiCoO2, 25% LiNiO2 cell. The Li x C/LiNiO2 cell had a higher self-discharge rate than the Li x C/75% LiCoO2, 25% LiNiO2 cell. The heat dissipated during discharge increased with the rate of discharge. During charge, initial endothermic cooling and subsequent exothermic heating beyond 55% state-of-charge were observed. At the C/2 rate of discharge (medium rate), the heat dissipated was 17mW/cm3 for the Li x C/LiNiO2 cell and 11.2mW/cm3 for the Li x C/75% LiCoO2, 25% LiNiO2 cell. The experimental values obtained for the heat dissipation at various charge and discharge rates were used to calculate thermoneutral potentials of 3.698 and 3.836V for the Li x C/LiNiO2 and Li x C/75% LiCoO2, 25% LiNiO2 cells, respectively. The proposed values for thermoneutral potential may explain the endothermic cooling during charge and the negative temperature coefficient for cell voltage.
For improvement of vanadium redox flow battery (VRB) performance, novel amphoteric semi-interpenetrating membranes (ASIPN) were prepared using poly(ether ether ketone) (PEEK) and polysulfone (PSf), the former bearing sulfonic groups and the latter imidazolium. These two groups form ionic crosslinks between PEEK and PSf; meanwhile, covalent cross links were built between PSf chains with addition of N-(3-aminopropyl)-imidazole. The amphoteric nature of the membrane allows facile proton and anion transport; the IPN structure and the presence of imidazolium cation effectively suppress vanadium ion crossover through the membrane. Therefore, the ASIPN based VRBs show higher Coulombic efficiency and energy efficiency than that assembled with pristine SPEEK and Nafion 212 membranes. Our work demonstrates that the ASIPN membranes are promising for VRB applications.
The electrochemical performance of negative electrodes (anodes) made from mesocarbon microbeads (MCMB) in lithium-ion cells has been studied systematically via a variety of electrochemical techniques. The MCMB anodes have a stable lithium intercalation capacity of 325mAhg−1 on high-rate charge–discharge cycling. Cyclic voltammetry shows only one reduction peak and one oxidation peak, which correspond to lithium-ion intercalation and de-intercalation, respectively. The diffusion of lithium ions in MCMB electrodes is characterized by ac impedance measurements.
The room temperature sodium-sulfur (RT Na-S) batteries have attracted extensive attention due to its low cost and high specific energy. Yet, RT Na-S batteries usually suffer from low reversible capacity, short lifespan and inferior Coulombic efficiency. Herein, covalent sulfur based carbonaceous materials was investigated for RT Na-S battery to address these drawbacks. Generally, the covalent S could prevent the formation of sodium polysulfide (Na2Sn, 4≤n≤8) effectively, further avoid the dissolution of sodium polysulfide into electrolyte; besides, the covalent S in these carbonaceous materials is reversible during charge/discharge process, which is good for cycling stability. Benefiting from these merits, the covalent sulfur based materials delivers high reversible capacity over 1000mAhg−1, long cycling stability for 900 cycles with capacity decay of 0.053% per cycle and superior Coulombic efficiency approximately 100%. This study may provide a new method for designing high performance RT Na-S batteries.
The objective of this study was to compare the efficacy of computer-assisted TBI using a smart toothbrush (ST) and smart mirror (SM) in plaque control to that of conventional TBI.
The present work introduces a new intercalation host for the Na ions, Nb2O5, and proposes that a mesoporous Nb2O5/carbon composite can function as a promising sodium insertion material. The highly ordered mesoporous Nb2O5/carbon electrode, synthesized using a block copolymer-assisted one-pot method, demonstrated not only a stable cycle life, but also outstanding rate capability. The excellent Na storage properties of the Nb2O5/carbon electrode were due to the uniquely ordered mesoporous nanostructure and in situ carbon formation whose configuration provided a large electrode–electrolyte interface area and enhanced Na ion and electron transport. Ex situ analyses revealed that Nb2O5 stores Na ions through Na de/intercalation reactions combined with surface capacitive reactions, after the activation process during the first sodiation.
A mathematical model for analysis and prediction of the performance of the aluminum–air cell has been developed. The model takes into account the kinetics of the anode, cathode, and parasitic reactions. Ohmic losses in the electrolyte and mass transfer are also taken into account. The model prediction of cell performance shows good agreement with experimental data. The mathematical model provides detailed information about cell performance for a wide range of operating and design parameters. For better cell performance, our model studies suggest the use of higher electrolyte flow rates, smaller cell gaps, higher conductivities, lower parasitic current densities and operation at moderate current density. From our analysis, we have determined that, in an aluminum air cell, only the activation and ohmic overpotential are important.
The metal-organic frameworks (MOFs) have gained considerable attention owing to their unique structures with tunable three-dimensional porous frameworks and numerous applications. The large surface area and great porosity make MOFs a promising electrode material for lithium-ion batteries. In this work, the focus is placed on an unexplored key issue, i.e., the impact of lithiation/delithiation on the structure of MOFs as anode materials. To do so, Al-MOF (chemical formula: Al(OH)[O2C–C6H4–CO2]) particles are synthesized, and then uniformly covered by graphene to form the Al-MOF/graphene composite. It is found that the lithiation/delithiation induces a pronounced structural change in the Al-MOF particles, which manifests as an order-disorder transition. This transition leads to the more open channels, thereby benefiting the diffusion and storage of Li+ ions. Compared with pure Al-MOF, the Al-MOF/graphene composite exhibits significantly enhanced electrochemical performances. Its capacity increases continuously from 60 to 400 mAh g−1 at the current density of 100 mA g−1. This work indicates that both the lithiation/delithiation induced order-disorder transition in MOFs and the optimized wrapping of MOF by graphene are crucial for enhancing the capacity and the cycling stability of anode materials.
Objective Narcolepsy with cataplexy (NC) is a chronic disabling disease; however, there are insufficient data on older NC subjects. Methods A cross-sectional evaluation on health and social status, including intensity and progression of NC symptoms, was performed on 42 NC patients (age 71.9 years ± 7.5) and 46 age-and-sex-matched controls (age 72.2 years ± 7.0). Results A greater proportion of patients than controls suffered from hypertension and type 2 diabetes. More controls had a history of treated depression; however, according to the Geriatric Depression Scale, more NC patients scored in the range of depression. There were no significant differences in Addenbrook Cognitive Examination scores. Average physical fitness assessed by the Short Physical Performance Battery was lower in the NC group. The frequency of meeting with family, friends, and participation in hobbies or sports did not differ between the two groups. Conclusions Symptoms of NC were present throughout life. Comorbidities and lower physical fitness, which are known to be present in young and middle-aged NC subjects, were also present in older patients. Although NC subjects were less professionally active during their lifetime, they did not differ from controls in important social parameters in older age.
Online programs targeting lifestyle have the potential to benefit brain health. We aimed to develop such a program for individuals with subjective cognitive decline (SCD). These individuals were reported to be at increased risk for dementia, and report both an intrinsic need for brain health information and motivation to participate in prevention strategies. Co-creation and user-evaluation benefits the adherence to and acceptance of online programs. Previously, we developed a prototype of the online program in co-creation with the users.