batterydata/paper-abstracts huggingface dataset:
Hierarchical mesoporous hybrid NiO–MnCo2O4 microspheres are synthesized by a robust one-pot spray pyrolysis process. The mesoporous hybrid NiO–MnCo2O4 microspheres are comprised of homogeneously dispersed nanoscaled NiO and MnCo2O4 subunits. Specific surface area of the mesoporous hybrid NiO–MnCo2O4 microspheres is determined to be 10.2m2 g−1 with dominant pore size of 25.8nm. The as-obtained material is evaluated as anode material for LIBs. The as-prepared hybrid NiO–MnCo2O4 sample demonstrate better electrochemical performances, including higher reversible capacity and superior rate capability, compared with the single-phase NiO and MnCo2O4 samples. These superior electrochemical performances should be mainly attributed to its porous microstructure characteristics and the synergistic effects between the well-dispersed NiO and MnCo2O4 nanophases. The strategy is simple and flexible, so it could be readily generalized to construct other hybrid metal oxides materials.
Background Cholinergic deficits have been largely correlated to behavioral disorders in dementia. However, cholinergic deficits are not homogeneous and they are distributed differently in the basal forebrain and brainstem among Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). The different cholinergic networks involved suggest different patterns of behavior symptomatology in the two groups. Objective To correlate the deficit of cholinergic activity, measured in vivo by the short latency afferent inhibition (SAI) technique, with the behavioral symptoms in patients affected by DLB and AD. Methods Behavioral and neuropsychologic tests including Neuropsychiatric Inventory (NPI), mini-mental status examination (MMSE), and an extensive neuropsychologic investigation were administered to 18 DLB patients and 18 one-to-one matched AD patients. SAI data were compared with those from a control group of age-matched healthy individuals and the level of SAI in patients was correlated with behavioral measures. Results AD tended to be more impaired than DLB on long-term memory, whereas DLB were more impaired than AD on constructional praxis tasks. NPI total score was similar but with a different behavioural pattern in DLB and AD. In particular, delusions and hallucinations prevailed in DLB patients, whereas affective disturbances prevailed in AD patients. SAI was significantly reduced both in AD and DLB patients when compared with controls; SAI correlated with hallucinations in DLB patients and with euphoric manic state and disinhibition in AD patients. Conclusions Reduction of cholinergic activity as evaluated by SAI measurement correlates with different behavior disorders in AD and DLB patients.
The aim of this study was to determine factors associated with physical fitness (PF) in children who underwent surgery for congenital heart disease (CHD). Sixty-six children (7–14 years) who underwent surgery for ventricular septal defect (n = 19), transposition of great arteries (n = 22), coarctation of aorta (n = 10), and tetralogy of Fallot (n = 15) were included. All children performed PF tests: cardiorespiratory fitness, upper- and lower-limb muscle strength, speed, balance, and flexibility. Cardiac evaluation was done via echocardiography and cardiopulmonary exercise test. Factors related to child’s characteristics, child’s lifestyle, physical activity motivators/barriers, and parental factors were assessed. Linear regression analyses were conducted. The results showed no significant differences in physical activity (PA) level by CHD type. Boys had better cardiorespiratory fitness (difference = 1.86 ml/kg/min [0.51;3.22]) and were more physically active (difference = 19.40 min/day [8.14;30.66]), while girls had better flexibility (difference = − 3.60 cm [− 7.07;− 0.14]). Physical activity motivators showed an association with four out of six PF components: cardiorespiratory fitness, coefficient = 0.063 [0.01;0.11]; upper-limb muscle strength, coefficient = 0.076 [0.01;0.14]; lower-limb muscle strength, coefficient = 0.598 [0.07;1.13]; and speed, coefficient = 0.03 [0.01;0.05]. Age, sex, and motivators together reached a maximum adjusted R2 = 0.707 for upper-limb strength. Adding other possible determinants did not significantly increase the explained variance. Apart from age and sex as non-modifiable determinants, the main target which might improve fitness would be the introduction of an intervention which increases the motivation to be active.
In previous decades a substantial number of community-based studies mostly including dementia cases examined predictors of nursing home admission (NHA) among elderly people. However, no one study has analysed predictors of NHA for individuals without developing dementia before NHA.
Inter-firm strategic technology collaborations are more and more frequently used as a source of knowledge. American corporations do not just collaborate among themselves, but they have proven to be very attractive partners also for European Corporations. However, technological co-operation among European firms strongly declined in the 1990s, not only in relative terms, but also in absolute terms. We compare these trends with what has happened in academic collaborations measured by scientific co-authored papers. In this domain, Europeans are more and more likely to collaborate among each other, and they are also becoming more attractive for American scientists. Since one of the core objectives of the European Union science and technology policy has been to foster collaboration, we can deduct that this has been a success in the field of academia, but a failure in the business field. A few tentative explanations and policy implications are addressed.
Cuprous oxide-coated graphite was synthesized by a polyol reduction process and analyzed by scanning electron microscopy, charge–discharge measurements and cyclic voltammetry. Cu2O exists at the surface of graphite in the form of nanoparticles and nanorods. The coated cuprous oxide layer acts as a protective layer separating graphite from the propylene carbonate (PC)-based electrolyte solution, and greatly suppresses PC decomposition and graphite exfoliation in PC-based electrolyte systems.
Lithium sulfur (Li-S) batteries possess high theoretical specific capacity (1675mAhg−1) and energy density (2567Whkg−1), but are plagued by their poor rate performance. The discovery of new carbon sources, design of novel porous carbon structures, and effective hetero-atom doping of the sulfur matrix are key to overcome this dilemma. In this paper, a boron-doped porous carbon material with a termite nest shape (TNPBC) was obtained from a new carbon source, polyaspartic acid, and borax. Importantly, the doping, activation, and pyrolysis were integrated into one step through a low cost and simple methodology. The borax was essential to formation of a high surface porous architecture and provided boron dopants, which, combined with polyaspartic acid, achieves co-doping (B and N) carbon materials with special porous structures. The simultaneous pore-formation and doping leave an abundance of hetero-atoms exposed on the surface of pores, which enhances the electrostatic interactions between the hetero-atoms and the charged species in the batteries. As a result, the S/TNPBC cathode maintains a stable capacity of 703mAhg−1 with an excellent Coulombic efficiency of 101.3% after 120 cycles at 0.1C. Moreover, it exhibits an excellent rate capability with an initial capacity of 650mAhg−1 at 0.5C and sustains a capacity of 500mAhg−1 after 100 cycles. Furthermore, when TNPBC is used as the anode in a sodium ion battery, an excellent rate capability is achieved. The specific charge capacity is three times greater than without boron doping at 500mAg−1. Due to the simple fabrication process and desirable properties of this novel architecture, TNPBC provides a new strategy for enhancing the performance of commercial energy storage devices.
We describe a simple method to embed cobalt metal nanoparticles in porous carbon nanorods (Co-CNRs) as a suitable nanostructured electrode material for electrochemical capacitor (EC) applications. The Co-CNRs is synthesized by an easy and versatile electrospinning technique and followed by one step carbonization at 900°C in Ar atmosphere. Comparative studies with different cobalt loading are performed to optimize the minimum cobalt presence in different Co-CNRs to improve specific capacitance as well as life cycle. Cobalt enriched carbon nanorods with a specific surface area (SBET) of 476.1 m2g−1, pore volume of 0.3811 cm3 g−1 and pore sizes ranging from 1.18nm to 3.78nm are developed. Electrochemical investigations are carried out using cyclic voltammetry (CV), galvanostatic charge-discharge techniques and electrochemical impedance spectroscopy (EIS). Appreciable capacitance retention is observed, 101 Fg−1at a high scan rate of 100 mVs−1 and 108 Fg−1at a high discharge current of 5mA. The porous Co-CNR exhibited excellent cycle stability at 50 mVs−1 for 5000 cycles in aqueous 0.5M H2SO4 electrolyte.
Direct methanol fuel cells have been characterised under ambient conditions. By operating the cathode with hydrogen as well as air, the half-cell and full-cell overvoltages have been found. Both the anode and the cathode kinetics improve with increasing temperature, but the cathode suffers from additional losses due to methanol crossover and water flooding. The methanol concentration, however, mainly influences the cathode. Impedance spectroscopy measurements on single cells and stacks confirm these results, and indicate that water removal from the cathode is important for stable operation of direct methanol fuel cells. Carbon dioxide (CO2) in the cathode outlet was measured by mass spectroscopy (MS). The amount of carbon dioxide crossover is noticeable compared to the methanol crossover, but decreases with temperature and methanol concentration. Almost 100% of the crossover methanol is converted to carbon dioxide at the cathode.
To explore advanced anode materials for lithium-ion batteries of electric vehicles, Cu2+/Nb5+ co-doped TiNb2O7 is studied. Cu0.02Ti0.94Nb2.04O7 is successfully fabricated using a facile solid-state reaction. X-ray diffraction analyses combined with Rietveld refinements demonstrate that the trace Cu2+/Nb5+ co-doping does not destroy the shear ReO3 crystal structure of TiNb2O7 but increases the lattice parameters and unit cell volume. Specific surface area tests and scanning electron microscopy images reveal a smaller average particle size in Cu0.02Ti0.94Nb2.04O7. Due to the increased unit cell volume and free 3d electrons in Cu2+ ions, the Li+-ion diffusion coefficient and electronic conductivity of Cu0.02Ti0.94Nb2.04O7 are respectively enhanced by 14.8 times and at least 220 times. Consequently, Cu0.02Ti0.94Nb2.04O7 exhibits advanced electrochemical properties in terms of specific capacity, rate capability and cyclic stability. At 0.1 C, it delivers a large first-cycle discharge/charge capacity of 346/315 mAh g−1. At 10 C, it still provides a large capacity of 182 mAh g−1 with tiny loss of only 1.2% over 1000 cycles. In sharp contrast, TiNb2O7 shows a small capacity of only 90 mAh g−1 and large loss of 59.8%. Therefore, Cu0.02Ti0.94Nb2.04O7 possesses great potential for the application in lithium-ion batteries for electric vehicles.
In this study, GO-MOFs derived rGO coating/sandwiching Co3O4 composites (denoted as rGO/Co3O4) are fabricated by employing a temperate coprecipitation method with ZIF-67 rhombic dodecahedron as a template and GO as a substrate. In these composites, nanoporous and rGO coating (denoted as rGO@Co3O4)/sandwiching (denoted as Co3O4-rGO-Co3O4) structures are designed, which endow the composites with strong potential application as electrode materials for lithium-ion batteries (LIBs) and supercapacitors (SCs). Here, the as-prepared rGO@Co3O4 and Co3O4-rGO-Co3O4 composites not only exhibit outstanding lithium storage performances with high initial discharge specific capacities (1451 and 1344mA h g−1 at a current density of 100mAg−1), excellent cycling stabilities (above 96% and 95% retention after 100 cycles) and admirable rate capabilities (328 and 450mA h g−1 at a current density of 2000mAg−1), but also display superior pseudocapacitive properties with high specific capacitance (546Fg−1), remarkable rate capability and brilliant cycling stability (90% of initial capacitance retention at 5Ag−1 after 10000 cycles). The remarkable porous architecture and electrical conductivity enables GO-MOFs derived transition metal oxide composites to be promising electrode materials for next generation LIBs and SCs.
The remarkable characteristics of nanofibers mats electrospun are large surface area to volume ratio and high porosity, which are crucial to increase the ionic conductivity of membrane full of liquid electrolyte, in this aspect, electrospinning is prior to the other methods, such as dry method, wet method, etc. Therefore, fabricating the separator of Li-ion batteries by electrospinning is potential and promising. The PVDF membranes were fabricated by electrospinning. The experiment demonstrated that the main deficiency in the fabricating separators process by electrospinning was low mechanical property, which induced partial short circuits inside the cells. Several methods were presented to enhance the mechanical strength. The experiments demonstrated that the higher the solution concentration was, the stronger the mechanical strength was, and the higher the voltage was, the stronger the mechanical strength was. Additionally, the spherical hat collection target instead of conditional plane target was applied in the electrospinning system, as a result, the thickness of the membrane was more uniform and the fiber diameter was also more uniform. Therefore, the charge and discharge capacity of the coin type cell composed of the separator collected by spherical hat target exceeded the plane target, and the electrospinning separators exceeded the commercial polypropylene separator.
In this work, we explored the use of heat pipe as cooling device for a specific HEV lithium-ion battery module. The evaporator blocks of heat pipe modules were fixed to a copper plate which played the role of the battery cooling wall. A flat heater was glued to the other surface of the copper plate and reproduced heat generated by the battery. The temperature at the cooper plate/heater interface corresponds to that of the battery module wall. An AMESim model of the battery was developed to estimate the cells' temperature within the battery. In inclined positions, a very slender evolution of the cooper plate/heater interface temperature was noticed, which means heat pipe works efficiently under different grade road conditions. Even though natural convection and chimney effect are not enough, coupling heat pipes with a confined ventilation structure is an efficient way to keep cells' temperature within its optimal range with an even temperature distribution. Furthermore, only low rate ventilation is necessary, which helps avoid parasitic power consumption and noise level in the vehicle.
In this report, mechanically compliant gel polymer electrolyte (GPE) for flexible lithium-ion batteries is facilely fabricated. The GPE that based on the poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) (P(MA-co-AN)/PVA) was prepared via emulsion polymerization. Herein, the P(MA-co-AN) copolymer is anticipated to exert beneficial for the bendability of the GPE, as well as swollen with the liquid electrolyte to provide a facile pathway for ion movement. The PVA serves as a stabilizer during the emulsion polymerization and a mechanical framework for the compliant polymer membrane. Performance benefits of the mechanically compliant membrane are elucidated in terms of mechanical behavior, thermostability and ionic conductivity. The GPE is still self-standing and mechanical flexible after swollen with liquid electrolyte. The GPE displays a conductivity of 0.98mScm−1 with the uptake electrolyte up to 150% of its own weight at 30°C, excellent electrochemical stability window (5.2V vs. Li/Li+) and favorable interfacial characteristics. When used in flexible lithium-ion batteries, such a GPE demonstrates satisfactory compatibility with LiCoO2 and graphite electrodes.
The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structured Si/C composite (denoted as TSC-PDA-B) has been intelligently designed by rational engineering and precise control. In the novel structure, the multiple Si nanoparticles with small size are successfully encapsulated into the porous carbon shells with double layers benefiting from the strong etching effect of HF. The TSC-PDA-B product prepared is evaluated as anode materials for lithium-ion batteries (LIBs). The TSC-PDA-B product exhibits an excellent lithium storage performance with a high initial capacity of 2108 mAh g−1 at a current density of 100 mA g−1 and superior cycling performance of 1113 mAh g−1 over 200 cycles. The enhancement of lithium storage performance may be attributed to the construction of hybrid structure including small Si nanoparticles, high surface area, and double carbon shells, which can not only increase electrical conductivity and intimate electrical contact with Si nanoparticles, but also provide built-in buffer voids for Si nanoparticles to expand freely without damaging the carbon layer. The present findings can provide some scientific insights into the design and the application of advanced Si-based anode materials in energy storage fields.
ABSTRACT Room temperature ionic liquids are considered as potential electrolytes for high performance and safe lithium batteries due to their very low vapor pressure and relatively wide electrochemical and thermal stability windows. Unlike organic electrolytes, ionic liquid electrolytes are molten salts at room temperature with dissociated cations and anions. These dissociated ions interfere with the transport of lithium ions in lithium battery. In this study, a mathematical model is developed for transport of ionic components to study the performance of ionic liquid based lithium batteries. The mathematical model is based on a univalent ternary electrolyte frequently encountered in ionic liquid electrolytes of lithium batteries. Owing to the very high concentration of components in ionic liquid, the transport of lithium ions is described by the mutual diffusion phenomena using Maxwell-Stefan diffusivities, which are obtained from atomistic simulation. The model is employed to study a lithium-ion battery where the electrolyte comprises ionic liquid with mppy+ (N-methyl-N-propyl pyrrolidinium) cation and TFSI− (bis trifluoromethanesulfonyl imide) anion. For a moderate value of reaction rate constant, the electric performance results predicted by the model are in good agreement with experimental data. We also studied the effect of porosity and thickness of separator on the performance of lithium-ion battery using this model. Numerical results indicate that low rate of lithium ion transport causes lithium depleted zone in the porous cathode regions as the porosity decreases or the length of the separator increases. The lithium depleted region is responsible for lower specific capacity in lithium-ion cells. The model presented in this study can be used for design of optimal ionic liquid electrolytes for lithium-ion and lithium-air batteries.
The limited battery power, unpredictable mobility and large variation of received signal strength in nodes of Mobile Ad Hoc Networks (MANETs) create link and node vulnerability and instability. Multicast routing in MANETs for group communication requires the establishment of reliable links between neighboring nodes called as reliability pair beginning from the source and extending such reliability pairs enroute to the destination. We propose a scheme for Multipath Multicast Routing in MANETs using reliable Neighbor Selection (MMRNS) mechanism. A mesh of multipath routes are established from source to multicast destinations using neighbors that have high reliability pair factor. MMRNS operates in the following phases. (1) Computation of reliability pair factor based on node power level, received differential signal strength between the nodes and mobility. (2) Pruning neighbor nodes that have reliability pair factor smaller than a threshold. (3) Discovery of multipath multicast mesh routes with the help of request and reply packets. (4) Multipath priority assignment based on minimum value of reliability pair factor of a path and information transfer from source to the multicast destinations and (5) route maintenance against link/node failures. The scheme is simulated to evaluate the performance parameters like packet delivery ratio, memory overhead, message overhead, control overhead and packet delays in comparison to the mesh based multicast routing protocols such as On-demand Multicast Routing Protocol (ODMRP) and Enhanced ODMRP (EODMRP). MMRNS performs better than ODMRP and EODMRP as observed from the simulation results.
The removal of toxic hexavalent chromium (Cr(VI)) from polluted water by magnetic polyaniline (PANI) polymer nanocomposites (PNCs) was investigated. The PNCs were synthesized using a facile surface initiated polymerization (SIP) method and demonstrated unique capability to remove Cr(VI) from polluted solutions with a wide pH range. Complete Cr(VI) removal from a 20.0 mL neutral solution with an initial Cr(VI) concentration of 1.0–3.0 mg L−1 was observed after a 5 min treatment period with a PNC load of 10 mg. The PNC dose of 0.6 g L−1 was found to be sufficient for complete Cr(VI) removal from 20.0 mL of 9.0 mg L−1 Cr(VI) solution. The saturation magnetization was observed to have no obvious decrease after treatment with Cr(VI) solution, and these PNCs could be easily recovered using a permanent magnet and recycled. The Cr(VI) removal kinetics were determined to follow pseudo-first-order behavior with calculated room temperature pseudo-first-order rate constants of 0.185, 0.095 and 0.156 min−1 for the solutions with pH values of 1.0, 7.0 and 11.0, respectively. The Cr(VI) removal mechanism was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and energy-filter transmission electron microscopy (EFTEM). The results showed that PANI was partially oxidized after treatment with Cr(VI) solution, with Cr(VI) being reduced to Cr(III). The EFTEM observation indicated that the adsorbed Cr(III) had penetrated into the interior of the PNCs instead of simply adsorbing on the PNC surface. This synthesized material was found to be easily regenerated by 1.0 mol L−1p-toluene sulfonic acid (PTSA) or 1.0 mol L−1 hydrochloric acid (HCl) and efficiently reused for further Cr(VI) removal.
Electric aircraft offer an aviation decarbonization pathway and attract increasing attention owing to the rapid development of batteries. Here Andreas Schäfer and colleagues analyse the potential technological, economic and environmental viability of battery-electric commercial aircraft.
mPhase Technologies Inc of Little Falls, New Jersey has improved the design of the nanostructure component used in its ‘smart' battery that is currently under development. The improvement will make it easier for the company to manufacture the battery.
The paper explores the application of combination and permutation concepts with related probability calculations to specific examples taken from electrochemical science and engineering. Binomial, hypergeometric, negative binomial, geometric, multinomial, extended hypergeometric distribution, and the F-variance ratio approach are considered.