batterydata/paper-abstracts huggingface dataset:
Graphene, a one-atom layer of graphite, possesses a unique two-dimensional (2D) structure, high conductivity and charge carrier mobility, huge specific surface area, high transparency and great mechanical strength. Thus, it is expected to be an ideal material for energy storage and conversion. During the past several years, a variety of graphene based materials (GBMs) have been successfully prepared and applied in supercapacitors, lithium ion batteries, water splitting, electrocatalysts for fuel cells, and solar cells. In this review, we will summarize the recent advances in the synthesis and applications of GBMs in these energy related systems. The challenges and prospects of graphene based new energy materials are also discussed.
We conducted a population-based study on Developmental Coordination Disorder (DCD) in mainland China to explore the influence of one-child status in Chinese families on DCD. A total of 4001 children selected from 160 classes in 15 public nursery schools. The Movement Assessment Battery for Children assessed motor function. The prevalence of DCD in Chinese one-child families (8.7%) was higher than that in multi-child families (5.9%). Chinese one-child family status (compared with younger children in multi-child families) were negatively related with total score (−1.793), Manual dexterity (−0.228), Aiming and catching (−1.145), Balance (−0.433) of MABC-2 and DCD (OR=2.294) when adjusted for the children's and family's characteristics, and perinatal factors (each p <0.05). As one of the studies in this Chinese context, it provides a platform for future intervention programs in one-child families in preventing children's developmental disorders.
A new concept cathode was proposed to improve the safety of lithium rechargeable batteries. The cathode contains a positive temperature coefficient (PTC) compound that can drastically increase resistivity at more than a specified temperature (PTC properties). A PTC cathode containing the PTC compound was fabricated and its resistivity was evaluated. The resistivity of PTC cathodes increased by several tens at 130–140°C, which is the melting point of polyethylene. In lithium rechargeable batteries using these cathodes (PTC cell), a level nearly reaching the designed capacity is obtained at less than 1C rate. The discharge capacity of PTC cells became high as the content of PTC compound increases. Moreover, under 3C discharge condition, the voltage of PTC cell dropped at 138°C where the resistivity of the PTC cathode drastically increased. Additionally, on the external short circuit test at 145°C, the short circuit current of the PTC cell was almost 0A. These results indicate that PTC cathodes will improve the battery safety.
This paper analyses the application of artificial intelligence techniques to various areas of archaeology and more specifically: (1) the use of software tools as a creative stimulus for the organization of exhibitions; the use of humanoid robots and holographic displays as guides that interact and involve museum visitors; (2) the analysis of methods for the classification of fragments found in archaeological excavations and for the reconstruction of ceramics, with the recomposition of the parts of text missing from historical documents and epigraphs; (3) the cataloging and study of human remains to understand the social and historical context of belonging with the demonstration of the effectiveness of the AI techniques used; (4) the detection of particularly difficult terrestrial archaeological sites with the analysis of the architectures of the Artificial Neural Networks most suitable for solving the problems presented by the site; the design of a study for the exploration of marine archaeological sites, located at depths that cannot be reached by man, through the construction of a freely explorable 3D version.
The trend towards point-of-care and the advance in mobile technologies bring the potential to employ Mobile Nursing Information Systems (MNIS) in nursing care routines. However, adopting the MNIS is not simply a case of purchasing the required hardware and software, but rather a social interaction process between users, organizations, and the environment. Therefore, this study developed a framework of twelve factors affecting the decision to adopt/not to adopt the MNIS in the nursing department, and tested it from the perspective of the nursing administrators. A mail survey was conducted to collect the opinions of 84 nursing administrators, and a discriminant analysis was used to identify the critical factors for the adoption/non-adoption of the MNIS. Business competition, external suppliers’ support, and internal needs were identified as being significantly associated with the adoption of MNIS. Potential adopters can apply the results of this study as a reference when making the adoption decision regarding MNIS, while non-adopters and vendors can examine the resistance to MNIS.
Free base and Pd(II) 5,10,15,20-tetrakis(4-N,N-diphenylaminophenyl)porphyrin form conductive, stable and reproducible electropolymer films. The combined electrochemical and spectroscopic studies show that the electropolymerization mechanism involves the dimerization of triphenylamine units, conducting the formation of a tridimensional structure where porphyrin cores are in a perpendicular fashion that avoids aggregation. Switching between the polymer neutral and oxidized states produced color changes which can be observed by the naked eye, and the films showed to be efficient in the generation of photoelectric effects. All these characteristics make the polymers as promising materials for application in optoelectronic devices.
Porous (P-) and dense (D-) lithium titanate (Li4Ti5O12) powders as an anode material for lithium-ion batteries have been synthesized by spray drying followed by solid-state calcination. Electrochemical testing results showed that the discharge capacities of P-Li4Ti5O12 are 144mAh/g, 128mAh/g and 73mAh/g at the discharging rate of 2C, 5C and 20C, respectively (cut-off voltages: 0.5–2.5V). The corresponding values for D-Li4Ti5O12 are 108mAh/g, 25mAh/g and 17mAh/g. The higher capacity of the P-Li4Ti5O12 at high charge/discharge rates was attributed to the shorter transport path of Li ions and higher electronic conductivity in the P-Li4Ti5O12 as a result of its smaller primary particle size and higher surface area compared with those of the D-Li4Ti5O12.
Stringent requirements are in place for the evaluation and registration of new compounds with biocidal or pesticidal activities. However, the registration requirements for established compounds from new suppliers or for established compounds produced by a different manufacturing process have been less clear and ambiguity exists as to how ‘equivalence of health hazards’ can unequivocally be demonstrated analytically and by toxicological assays. The case presented in this analysis focuses on the chiral pyrethroid transfluthrin (TFL) synthesized by esterification of an acid chloride and alcoholic moiety. According to any modifications of the process of synthesis and purification, new potentially highly toxic and yet chemically reactive impurities in low concentrations (<0.1%) may be formed. Amongst these, that with the structural alert ‘organic acid anhydride’ was given heightened concern as the most potent putative toxicologically significant impurity. The course taken in this analysis focused on the comparison of reference TFL with commercialized generic TFL from two alternative manufacturing sources in India and China. Despite their apparent high racemic purity, TFLs from generic sources were biologically less effective, genotoxic in the Ames’ assay, demonstrated sensory lung irritation and lung/skin sensitization in specialized bioassays. While the off-patent reference TFL was unequivocally negative in all assays (anhydride content not detectable, LOQ <0.01%), positive results with high batch-to-batch variability were a frequent outcome in generic TFLs. Tier I analytical assays failed to detect this relevant impurity in the absence of impurity-specific optimized analytical procedures. This finding suggests that a well-balanced combined approach of analytical and toxicological assays provides the best means to assure that all critical impurities are identified and accounted for. Similarly, putative ‘structural alert’-based toxicity tests proved to be more predictive than any indiscriminant battery of standard bioassays commonly applied to demonstrate equivalence, such as acute oral/dermal toxicity and/or eye/skin irritation assays.
Solid electrolytes could enable stable cycling of metallic Li anodes, which can offer drastic increases to the capacity of Li-ion batteries. However, little is known about the mechanics of the Li-solid electrolyte interface. This study combines electrochemical and mechanical characterization to correlate interface kinetics with adhesive strength. Cubic garnet with the Li6·25Al0·25La3Zr2O12 (LLZO) formulation was selected as a model solid electrolyte based on its high conductivity and stability against Li metal. Symmetric Li-LLZO cells were tested using electrochemical impedance spectroscopy to determine the interfacial resistance, Rint, and the adhesive strength of the Li-LLZO interface, σadh, was measured using a unique tensile test in an inert atmosphere. It was determined that the Rint is directly correlated to the adhesive strength of Li on LLZO. At the highest Rint in this study, 330 k·cm2 the σadh was 1.1 kPa and at the lowest Rint in this study, 7 ·cm2, σadh was 8 MPa. Furthermore, by optimizing the surface chemistry the wettability of LLZO was enhanced resulting in σadh exceeding the ultimate tensile strength of Li metal. The relationship demonstrated provides a deeper understanding of the mechanical properties of the Li-electrolyte interface, which will play an important role in the design of batteries employing metallic Li anodes.
This contribution describes a concept for the establishment of a competitive energy distribution network based on Liquid Organic Hydrogen Carrier (LOHC) compounds. These compounds are characterized by the fact that they can be loaded and un-loaded with considerable amounts of hydrogen in a cyclic process. This concept links the technical challenge of storing temporary and local energy over-production from regenerative sources with the vision of a sustainable, hydrogen-based mobility. The proposed LOHC compounds have many physico-chemical similarities to diesel. Thus, LOHCs could make use of the existing energy infrastructure (e.g. tank ships, storage tanks or fueling stations) and enable a slow and step-wise replacement of the existing hydrocarbon fuels by alternative LOHC fuels. We consider LOHCs as an attractive way to provide wind and solar energy for mobility applications in the form of liquid energy carrying molecules of similar energy storage densities and manageability as today's fossil fuels.
In-depth evaluation of the electrochemical performance of all-vanadium redox flow batteries (VRFBs) under operando conditions requires the insertion of a reliable reference electrode in the battery cell. In this work, an easy-to-make reference electrode based on silver–silver sulfate is proposed and described for VRFBs. The relevance and feasibility of the information obtained by inserting the reference electrode is illustrated with the study of ammoxidized graphite felts. In this case, we show that the kinetic of the electrochemical reaction VO2+/VO2 + is slower than that of V2+/V3+ at the electrode. While the slow kinetics at the positive electrode limits the voltage efficiency, the operating potential of the negative electrode, which is outside the stability widow of water, reduces the coulombic efficiency due to the hydrogen evolution.
An active power factor controller (PFC) integrated circuit, normally used in AC circuits, has been used for DC-to-DC boost conversion with a stable output voltage for a variable DC input voltage as obtained from photovoltaic (PV) sources. The circuit described here uses a power factor controller MC 34262 to give approximately 400VDC output for an input variation from 90 to 280VDC. The maximum efficiency achieved was 98% at 450W. Comparisons between AC and DC operations have been made.
LISICON-like materials are attracting attention as promising new Li-ion conductors with potential use in all-solid-state Li-ion batteries. Although the concept of cooperative diffusion mechanism has been discussed before, a detail understanding of the diffusion process is still lacking for this material. Here, an atomic-scale investigation of the Li10SiP2S12 (LSPS)-based system using advanced simulation techniques provides valuable insights into its Li-ion conducting mechanisms. We find that Li-ion conduction in LSPS occurs through a concerted motion of interstitial and lattice Li-ions, evidenced both from molecular dynamics trajectory analysis and energy barrier calculations. The cause for the cooperative migration is the existence of a low-barrier step, by which one Li-ion's migration helps another adjacent Li-ion's migration through mutually beneficial S atoms relaxation and electrostatic interaction. Cooperative migration occurs in the channels formed by connected LiS4 tetrahedrons through Li–Li interaction as well as dual-Li-sites. Cl-doping can enhance cooperative migration by a new low-barrier step due to more flexible PS3Cl and large oscillation of Li, which smoothes Li potential energy surface and enhances cooperative migration.
An LiMnPO4/C composite material with ordered olivine structure was synthesized by a microwave-assisted solvothermal process in 2:5 (v/v) water-diethylene glycol mixed solvents at 190°C for 5min. The sample was characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, charge/discharge tests, cyclic voltammetry, and electrochemical impedance spectroscopy. The prepared LiMnPO4/C particles exhibited an irregular flaky form coated with a uniform carbon layer (approximately 2–3nm thick). The prepared LiMnPO4/C composite exhibited a discharge capacity of 131.4 and 85.2 mAh·g−1 at 0.1C and 5C, respectively. It delivered a discharge capacity of 109.2 mAh·g−1 with a capacity retention ratio of approximately 99% after 50 cycles at 1C. Furthermore, this microwave-assisted solvothermal approach led to a significant decrease in the reaction time as compared to conventional hydrothermal/ solvothermal processes.
To improve the performance of LiFePO4, single phase Li1−x Na x FePO4/C (x =0, 0.01, 0.03, 0.05) samples are synthesized by in situ polymerization restriction–carbonthermal reduction method. The effects of Na doping are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that doped Na ion does not destroy the lattice structure of LiFePO4, while enlarges the lattice volume. Electrochemical test results show that the Li0.97Na0.03FePO4/C sample exhibits the best electrochemical performance with initial special discharge capacity of 158mAhg−1 at 0.1C. EIS results demonstrate that the charge transfer resistance of the sample decreases greatly by doping an appropriate amount of Na.
The stabilization of future CO2 atmospheric concentrations to levels that might prevent anthropogenic alterations of the world climate calls for tens of terawatts of carbon free renewable energy resources. The combined energy production potential of all known non-solar carbon-free renewable resources seems insufficient to meet these targets. Consequently, over the next decades solar energy, and in particular photovoltaics, is expected to fill the gap. In this work several mature photovoltaic technologies, ranging from silicon to thin films, and solar concentrator systems are analyzed. The estimates of the energy production limits are established for each technology, based on available global material reserves. It is shown that many existing technologies, albeit playing an important in the present sub-gigawatt energy production levels, are affected by severe material shortages, that would prevent their scale-up to the terawatt range. This is the case for thin film solar cells technologies based on CdTe and CIGS where the showstopper is the scarcity of tellurium and indium respectively. Despite the abundance of silicon, crystalline Si-based solar cells will hardly reach the terawatt range as additional scale-up of the technology will be impeded by the global reserves of silver, commonly used as electrode material. As for amorphous silicon and dye sensitized thin film technologies, avoiding the use of indium tin oxide transparent conductor films appears as a must for exceeding the few tenth of terawatt barrier. For existing III–V concentrator cells, operating under moderate concentration (<200X), terawatt year level may be afforded by circumventing the use of Ge substrates and by minimizing the use of In and Au in the cell fabrication process. In conclusion the study summarizes current material challenges for terawatt level deployment of the existing solar cells, and for each technology, identifies improvements and innovations needed for further scale-up.
Enzymatic hydrolysis lignin (EHL) as a by-product from biofuel processes is an abundant and low-value carbon matrix precursor. Porous carbon materials with high surface areas were usually derived from lignin by chemical activation but with a low degree of graphitization, which seriously reduced its electrochemical performance as energy storage material. In this work, the lignin-based carbon (LC) samples activated by different potassium compounds using EHL as a raw material were characterized by TG, EA, FT-IR, BET, TEM, XRD and Raman spectroscopy. The results showed that the influence of the four potassium compounds on the specific surface area (SSA) and pore volume of LC was as follows: K2CO3 > KOH > K2C2O4 > K3PO4. Interesting, we found that activator can improve the graphitization degree of LC, when the decomposition temperature of the activator is consistent with the activation temperature of lignin. In particular, K2CO3 can significantly improve the pore structure, surface area and graphitization degree simultaneously. Therefore, lignin-based carbon (LC-K2CO3-900) obtained by K2CO3 activation at 900 ℃ has more excellent electrochemical performance than that of other potassium compounds. LC-K2CO3-900 as the negative electrode of lithium ion battery can maintain a reversible capacity of 494 mAh g−1 after 200 cycles with a coulomb efficiency above 99% at a current density of 200 mA g−1. Even at 1000 mA g−1, it can still maintain a specific capacity of 260 mAh g−1. This porous carbon derived from low-cost renewable lignin sources is a good candidate for lithium ion battery electrode materials.
Gaseous hydrogen is confirmed to be the main component and primarily responsible for the inner pressure rise inside the 8-Ah Ni/MH batteries during fast charge. Based on a temperature-dependent pressure model proposed in this work, the kinetic characteristics of the hydrogen evolution were investigated. The overpotential and exchange current density were obtained by fitting the presented equation to the experimental data. Moreover, the profiles of hydrogen concentration during fast charge was further modeled and calculated according to the proposed mathematical model of hydrogen intercalation. It is indicated that diffusion step controls the fast charge performances and the higher the charge rate is, the more quickly the negative electrode attains to the maximum surface intercalation fraction, and however, the calculated results also show that further charge can reduce the difference of charge efficiency among the various rate during fast charge. Numerical investigations also reveal that the increase of diffusion coefficient and decrease of the particle size can efficiently improve the characteristics of fast charge, respectively.
Composite electrode materials of FeOOH-based particles and carbon powder were prepared with and without heat treatment of composite powder. The composite powder was obtained by hydrolyzing mixed aqueous solutions of FeCl3, Ti(SO4)2 and electron conducting carbon powder as acetylene black (AB) or Ketjen black (KB). FeOOH-based materials formed in the presence of Ti(IV) ions became amorphous and/or low crystalline structure. The composite powder worked as lithium insertion electrode materials in lithium cells using nonaqueous electrolytes including lithium ions. The electrodes exhibited a good cycle performance at large charge–discharge current densities over 5mAcm−2 (4Ag−1 per weight of active material). In addition, it was found that the cycle performance was effective process to be improved by the heat treatment of the composite materials. The composite materials such as amorphous FeOOH, α-Fe2O3, TiO2 and electron conductive powder obtained by the heat treatment are one of the promising candidates as electrode materials for energy storage devices, such as lithium-ion batteries and hybrid electrochemical supercapacitors.
To determine whether sleep and sleep disordered breathing (SDB) contribute to the neuropsychological deficits of patients with Down syndrome, and whether treatment of SDB results in improvement in cognitive function.
In a lithium secondary battery, the effect of the current rate affect on dendritic growth has been established. In the present, a series of experiments was conducted at a constant current rate, but at various the cell internal resistances. Different temperatures at −5°C, 15°C, and 35°C were applied to change the internal resistance. The present experiment found that as the resistance was varied, the voltage gradient also varied and accordingly to maintain a constant current rate, and that the Sand's time was measured differently at such varying voltage gradients. That voltage was also decreased together with the resistance to apply a constant current density results from Ohm's law. It was found that even if the current density remains constant, the size of the area where dendrites are generated will vary in accordance with the theory of solidification.
In Part I, we used computational fluid dynamics (CFD) to solve the Navier-Stokes equations surrounding the inert net in a parallel plate channel and presented the individual effects of the transverse and longitudinal ribs on the limiting current density distribution. The type, location, spacing, and number of the ribs of the net were shown to affect the local and average current density distributions on each of the two electrodes. In Part II, we present the combined effects of the longitudinal and transverse ribs on the limiting current distribution. We calculated the enhancement factors for both the combined and individual effects and compared. The longitudinal ribs decreased the average current density whereas the transverse ribs increased the average current density relative to the no-net parallel plate reactor system. A maximum enhancement of 250% in the average current density for a spacing of 0.94 × 10−3 m was obtained with 16 transverse ribs. For the same spacing, a negative 70% enhancement was obtained with 14 longitudinal ribs and no transverse ribs. A maximum enhancement of 180% was observed for the entire net (14 longitudinal and 29 transverse ribs). The enhancements at each electrode are different for a given geometry.