batterydata/paper-abstracts huggingface dataset:
According to the working principle of Lithium ion batteries, a perfect coating layer should not only be a lithium ion conductor but also an electronic conductor. In this work, the layered cathode material LiNi1/3Mn1/3Co1/3O2 was modified by a dual functional coating layer created from the Li-ion conductor Li2SiO3 and electronic conductor carbon. It was found that the modified LiNi1/3Mn1/3Co1/3O2 showed outstanding electrochemical performance after being coated with an appropriate content of Li2SiO3&C. Particularly, at the high current density of 5C (1C=160mA/g), the LiNi1/3Mn1/3Co1/3O2 coated with Li2SiO3&C could still deliver a discharge capacity of 96 mAh/g after 500 cycles with a capacity retention of 89.62%. In comparison, the pristine only delivered a discharge capacity of 71 mAh/g after 450 cycles. Furthermore, our strategy is convenient and universal, it can also be applied to other layered cathode materials to ameliorate their electrochemical properties.
It is well known that there is a strong influence of thermal processing variables on the solidification structure and as a direct consequence on the casting final properties. The morphological microstructural parameters such as grain size and cellular or dendritic spacings will depend on the heat transfer conditions imposed by the metal/mould system. There is a need to improve the understanding of the interrelation between the microstructure, mechanical properties and corrosion resistance of dilute Pb–Sn casting alloys which are widely used in the manufacture of battery components. The present study has established correlations between cellular microstructure, ultimate tensile strength and corrosion resistance of Pb–1wt% Sn and Pb–2.5wt% Sn alloys by providing a combined plot of these properties as a function of cell spacing. It was found that a compromise between good corrosion resistance and good mechanical properties can be attained by choosing an appropriate cell spacing range.
Nanostructured silicon with its high theoretical capacity and ability to accommodate volume expansion has attracted great attention as a promising anode material for Lithium ion (Li-ion) batteries. Liquid metal dealloying method, is a novel method to create nanoporous silicon (np-Si). The assembled Li-ion batteries based on such np-Si anode can be cycled beyond 1500 cycles, in 1000 mA h/g constant capacity cycling mode with consistent performance; however, it suffers from degradation after ~ 460 cycles, while being cycled under 2000 mA h/g. To reveal the failure mechanism and differences in the morphological evolution in different capacity cycling modes in the np-Si anode, we conducted synchrotron X-ray nano-tomography studies. The three dimensional (3D) morphological evolution was visualized and quantified as a function of the number of cycles and cycling capacities. By comparing the 3D morphology under each cycling condition and correlating these 3D morphological changes with cycling-life performance, we elucidate the failure mechanism of the np-Si electrodes resulting from a mesoscopic to macroscopic deformation, involving volume expansion and gradual delamination. In particular, the shorter cycling life in higher-capacity cycling mode stems from particle agglomeration. Overall, while the nanoporous structure can accommodate the volume expansion locally, these mesoscopic and macroscopic deformations ultimately result in heterogeneous stress distribution with faster delamination. The work thus sheds the light on the importance to consider the structural evolution at the mesoscopic and macroscopic scales, while designing nano-structured energy storage materials for enhanced performances, particularly for long cycling-life durability.
Tropical cyclone storm surge represents a significant threat to communities around the world. These surge characteristics vary spatially and temporally over a range of scales; therefore, conceptual frameworks for understanding and mitigating them must be cast within a context of risk that covers the complete range of hazards, their consequences, and methods for mitigation. A review of primary overlapping time scales and associated spatial scales for tropical cyclone surge hazards covers two scales of particular interest: (1) synoptic-scale predictions used for warnings and evacuation decisions and (2) long-term estimation of hazards and related risks needed for coastal planning and decision-making. Factors that can affect these estimates, such as episodic variations in tropical cyclone characteristics and longer-term climate change and sea-level rise are then examined in the context of their potential impacts on hazards and risks related to tropical cyclone surges.
Herein, we report on electrochemical doping of a conducting polymer (CP) with anionically modified graphene nanosheets. The architecture built from reduced graphene oxide (rGO) skeleton skinned by polypyrrole (pPy) enhanced supercapacitor performances especially at high discharge rates superior to those of the same CP with a conventional dopant: e.g., from 141 to 280Fg−1 at 1000C equivalent to ~50Ag−1. At relatively low rates, the graphene-doped pPy reached the theoretical capacitance of pPy, indicating efficient use of whole electroactive mass.
Micro-supercapacitors are a kind of state-of-the-art energy storage devices and have great potential to be developed in portable and wearable electronics. Here, we report a novel strategy for scalable fabrication of all-printed solid-state micro-supercapacitors with multilayer structure via multi-material 3D printing technique. To obtain electrode materials, we synthesize polypyrrole/polyaniline coaxis nanotubes by utilizing the self-degraded template polymerization method and in situ electrochemical polymerization. The as-prepared aqueous composite electrode ink shows significant shear thinning behavior and excellent processability: a complex electrode patterning with 484 retractions was proved. In addition, the inks are well-adapted to various substrates (paper, texitle, plastic film etc), allowing the device to be printed onto different substrates, even directly on the desired surface. As a conceptual exhibition, we design two schemes of in situ fabricated energy storage devices to meet the ever-changing energy needs and expand the application range of micro-supercapacitors. The transferable tape-type micro-supercapacitors can be stuck to any surfaces where energy is needed immediately. The in situ fabricated wearable micro-supercapacitor on lab-gown shows promising performance and excellent flexibility.
This work describes a route for extracting manganese and zinc from spent zinc–manganese dioxide dry cells via fusion of the electroactive components with potassium hydroxide to form potassium manganate (K2MnO4) and soluble zincates. The fused mass was dissolved in aqueous KOH and the insoluble matter was separated. Under the best optimal conditions, 70–78 wt% of manganese was solubilized as K2MnO4 whereas 30–44 wt% of zinc was solubilized as [Zn(OH)4]2− ions. Lead was the only minor component dissolved in detectable amounts. Manganese was isolated by a one-step precipitation procedure as barium manganate (BaMnO4) or via crystallization of K2MnO4. Lead and excess barium were isolated as sulfate by adding K2SO4. Zinc was precipitated as hydroxide after neutralizing the alkaline solution with H2SO4. pH control is essential to avoid decomposition of manganate ions and for the sequential precipitation of leached elements. K2SO4 was partially recovered as by-product after partial evaporation of the neutralized solution.
Background Childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes are the most common forms of benign epilepsy syndromes. Although cognitive dysfunctions occur in children with both childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes, the similarity between their patterns of underlying cognitive impairments is not well understood. To describe these patterns, we examined multiple cognitive functions in children with childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes. Methods In this study, 43 children with childhood absence epilepsy, 47 children with benign childhood epilepsy with centrotemporal spikes, and 64 control subjects were recruited; all received a standardized assessment (i.e., computerized test battery) assessing processing speed, spatial skills, calculation, language ability, intelligence, visual attention, and executive function. Groups were compared in these cognitive domains. Simple regression analysis was used to analyze the effects of epilepsy-related clinical variables on cognitive test scores. Results Compared with control subjects, children with childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes showed cognitive deficits in intelligence and executive function, but performed normally in language processing. Impairment in visual attention was specific to patients with childhood absence epilepsy, whereas impaired spatial ability was specific to the children with benign childhood epilepsy with centrotemporal spikes. Simple regression analysis showed syndrome-related clinical variables did not affect cognitive functions. Conclusions This study provides evidence of both common and distinctive cognitive features underlying the relative cognitive difficulties in children with childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes. Our data suggest that clinicians should pay particular attention to the specific cognitive deficits in children with childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes, to allow for more discriminative and potentially more effective interventions.
The carbon supported composite catalysts for Li-O2 batteries with optimized structure seem attractive in terms of their advantages of electronic conductivity and light weight. In this work, a facial solvothermal method was employed to prepare the composite with 34 wt% δ-MnO2 wrapped on the surface of MWCNTs in form of monomolecular layer by the chemical binding (δ-MnO2@MWCNTs). The experimental results indicate that δ-MnO2@MWCNTs retains the high specific surface area and abundant mesoporous structure of MWCNTs. Moreover, the dominated (002) facet and abundant oxygen vacancies of the δ-MnO2 layer accelerate the adsorption of O2 and elongate the O-O bond, which promote the oxygen reduction reaction activity. In particular, the oriented growth of discharge products (Li2O2) forming flake- and flower-like depositions with an increase of DOD ensures the stable reaction zone in the cathode with sufficient charge transfer and oxygen diffusion channel. Therefore, the Li-O2 batteries with δ-MnO2@MWCNTs as cathode catalysts demonstrate the high discharge capacity of 28517 mA h g−1 with the voltage platform of 2.82 V in the initial discharge (100 mA g−1) and the excellent rate performance with 75% capacity retention at current density of 1000 mA g−1. Meanwhile, the δ-MnO2 @MWCNTs catalysts are of benefit to the excellent electrochemical reversibility with 190 cycles (100 mA g−1) and 20 cycles (1000 mA g−1) under a limited discharge depth of 1000 and even 4000 mA h g−1, respectively.
Using a simple filtration method, we fabricate freestanding carbon-based composite paper electrodes (F-CCPEs), based on acid-treated carbon nanotubes (a-CNTs) and microporous carbon-based nanoplates containing numerous heteroatoms (H-CMNs). The F-CCPEs exhibited a high electrical conductivity of 2.3 × 102 S cm−1 and a high surface area of 1211.7 m2 g−1; moreover, they had numerous electroative heteroatoms and showed mechanical flexibility. Therefore, F-CCPEs without current collectors and binder show a superior electrochemical performance. In particular, the prepared F-CCPEs exhibit high capacitances of 275 and 148 F g−1 in aqueous and organic electrolytes, respectively. In addition, the specific energy density and specific power density of these F-CCPEs were found to be 63 Wh kg−1 and 140 kW kg−1, respectively, with good cyclic stability, even after 20,000 charge/discharge cycles.
The mechanical stability of inactive polymeric components (e.g. separator and binder) can play an important role in the long term performance of lithium-ion batteries. Here we investigate the effects of electrolyte solvents on the mechanical properties of a polypropylene battery separator through experimental measurements of thickness and elastic modulus of separator samples immersed in different solvent environments. We find that certain electrolyte solvents such as dimethyl carbonate, diethyl carbonate, and ethyl acetate cause noticeable softening of the separator. However, in other solvent environments such as propylene carbonate and acetonitrile, the separator retains the mechanical properties of a dry material. We show that the mechanical property reduction can be attributed to polymer swelling and explain these observations in the context of the Hildebrand solubility and Flory–Huggins interaction parameters. The solubility/interaction parameter analysis provides a straightforward method for predicting the in situ mechanical behavior of polymer separators in solvent environments. The relationships discussed herein can be used to screen and identify mechanically-stable polymer and electrolyte solvent pairs for use in lithium-ion batteries designed for long life.
Feasibility, safety, and utility of brain MRI for patients with non-MRI-conditioned cardiac implantable electrical devices (CIEDs) remains controversial. While a growing number of studies have shown safe employment in select patients under strict protocols, there is an increasing clinical need for further off-label investigations. To assess the feasibility and utility of brain MRI in neurological and neurosurgical patients with non-MRI-conditioned CIEDs using off-label protocol. We retrospectively evaluated 126 patients with non-MRI-conditioned CIEDs referred to our hospital between 2014 to 2018 for MRI under an IRB-approved protocol. A total of 126 off-label brain MRI scans were performed. The mean age was 67.5 ± 13.0. Seventy percent of scans were performed on female patients. Indications for MRI are neurosurgical (45.2%), neurological (51.6%), and others (3.2%). MRI utilization for tumor cases was highest for tumor cases (68.3%), but employment was valuable for vascular (12.7%), deep brain stimulators (3.2%), and other cases (15.9%). In the tumor category, (37.2%) of the scans were performed for initial diagnosis and pre-surgical planning, (47.7%) for post-intervention evaluation/surveillance, (15.1%) for stereotactic radiosurgery treatment (CyberKnife). No clinical complications were encountered. No functional device complications of the CIED were identified during and after the MRI in 96.9% of the studies. A 49.6% of the off-label brain MRI scans performed led to a clinically significant decision and/or intervention for the patients. A 42.9% of obtained MRI studies did not change the plan of care. A 7.9% of post-scan decision-making data was not available. We demonstrate that off-label brain MRI scans performed on select patients under a strict protocol is feasible, safe, and relevant. Almost 50% of scans provided critical information resulting in clinical intervention of the patients.
Hydrogen being clean energy source is an effective substitute to current fossil fuels. Present day advancement in hydrogen economy field has motivated researchers to work in green energy field. Different types of methods are in use to store hydrogen. Our review focuses initially on various types of sustainable and non-renewable energy sources, then with emphasis towards hydrogen economy, we discuss in details about it. Hydrogen is efficient candidate amongst vivid sustainable source of energy. Hydrogen advantages and its applications in different fields are covered. Initially discussing different methods to synthesize hydrogen, we shift towards the hydrogen storage methods. Amongst all the hydrogen storage methods, electrochemical method is best, as hydrogen is generated, stored in situ at normal pressure and temperature conditions. Different methods can be used to study hydrogen storage by electrochemical means. Various materials that can efficiently store hydrogen, were covered. Hydrogen is most common fuel in fuel cell, hence classification of hydrogen fuel cells and their relevance with respect to stationary and portable fields are covered.
A photoplethysmograph (PPG) is a simple medical device for monitoring blood flow and transportation of substances in the blood. It consists of a light source and a photodetector for measuring transmitted and reflected light signals. Clinically, PPGs are used to monitor the pulse rate, oxygen saturation, blood pressure, and blood vessel stiffness. Wearable unobtrusive PPG monitors are commercially available. Here, we review the principle issues and clinical applications of PPG for monitoring oxygen saturation.
A convenient and operable fabrication technique has been demonstrated for self-assembled vertically aligned anatase TiO2 nanowires on FTO glass with tunable length in the range of 15–55 μm for multi-layered configuration photoanode based DSSCs application. DSSCs based on 47 μm-long multi-layered anatase TiO2 nanowire arrays attain a power conversion efficiency of 9.40%, which is the highest value for nanowire array based DSSCs to date.
With the rapid development of electric vehicles (EVs), the impacts on power grids arising from EV charging have drawn increasing attention worldwide. Uncoordinated charging of large-scale EVs will inevitably elevate load peaks at rush hours, therefore, poses serious challenges to the stability and security of power grid. Coordinated charging is expected to alleviate these negative impacts by utilizing the surplus power in the lower-demand hours with the help of the so-called valley filling algorithm. Nevertheless, when the amount of EVs involved reaches 1 million or above, the complexity of the scheduling method becomes a critical issue. In this paper, a very high efficient valley-filling strategy is proposed. Two key indexes, viz., capacity margin index and charging priority index are defined, the former one is used to select the target time slots on which the power grid has abundant surplus power for EV charging, and the latter one is used to determine the charging priority of EVs on each time slot. The simulation results demonstrate that the coordinated charging scheme with the proposed valley-filling strategy significantly outperforms the uncoordinated charging in the aspect of suppressing the elevated peak loads of power grid. Moreover, the complexity analysis shows that the proposed algorithm is much high-efficient than its existing counterparts.
Recently, the low cost energy devices with high energy density and high power density are becoming more and more important in the field of electric vehicles. In this work, the electrochemical intercalation/deintercalation behaviors of PF6ˉ into graphitic mesocarbon microbead (MCMB) cathode are investigated in the electrolyte of 1 M LiPF6 in the mixed solvent of ethylmethyl carbonate and sulfolane. The charge storage mechanisms related to surface-limited capacitive and diffusion-controlled intercalation capacity are also studied by cyclic voltammetry measurements, which indicates that both the intercalation reaction and the capacitive reaction contribute to the overall capacity. Furthermore, dual-carbon batteries comprising MCMB cathode and pre-lithiated MCMB anode are unprecedentedly demonstrated in the form of aluminum pouch cells with laminated structure and exhibit an encouraging energy density of 47.9 Wh kg−1 at the power density of 583.6 W kg−1 based on the overall mass of the battery. Finally, electrochemical impedance spectroscopy is used to differentiate the resistance variation of MCMB cathode and MCMB anode before and after 3000 cycles. The continuous intercalation/deintercalation of PF6ˉ into MCMB cathode lead to the exfoliation of the active material and the increase of internal resistance.
Confabulation, the production of statements and actions that are unintentionally incongruous to the subject's history, background, present and future situation, is a rather infrequent disorder, observed in several conditions affecting the nervous system. Little is known about the quantitative and qualitative evolution of confabulation in time. In this study we evaluated longitudinally the evolution of this disorder in a group of severe confabulators, using the Confabulation Battery (CB), a sensitive tool to detect confabulations in various memory domains. It was found that confabulations were stable over time and not temporally limited. It was also found that “Habits Confabulations” (HCs), i.e., habits and repeated personal events mistaken as specific, unique past and future personal episodes, or well-known public events when semantic knowledge is concerned, was the more frequently observed type of confabulation. Confabulations were also more prominent in the domain of Temporal Consciousness (TC), i.e., a specific form of consciousness that allows individuals to remember their personal past, to be oriented in their present world and to predict their personal future, than in Knowing Consciousness (KC), i.e., a specific form of consciousness allowing individuals to be aware of past, present and future impersonal knowledge and information. Confabulations showed also persistence, i.e., confabulations at the same questions over time, and consistency, i.e., same type of confabulation at the same question over time. These findings are discussed within the framework of the Memory, Consciousness and Temporality Theory.
The urgent need for a stable, efficient, and affordable oxygen evolution reaction (OER) catalyst has led to the investigation of a vast amount of transition metal materials with multiple different anions. In situ and post catalytic characterization shows that most materials transform during the harsh OER conditions to layered (oxy)hydroxides (LOH). Several open questions concerning these in situ formed LOH remain such as: an explanation for their strongly varying activities, or the effect of the precatalyst structure, leaching anions, and transformation conditions on the formed LOH. Herein, we report on a cobalt selenite precursor, which, depending on pH and potential, transforms irreversibly into two different LOH OER catalysts. Combining multiple electrochemical and analytical methods ex and in situ, we prove that one of these products is near-surface catalytically active and the other one throughout the bulk with an in situ average cobalt oxidation state of 3.2. We deduce a detailed structural model explaining these differences and propose general concepts relating both the precatalyst structure and the transformation conditions to the final catalyst. Further, we apply these models to the most promising non-noble metal catalyst, NiFe LOH.
The effects of the reformer in an internal-reforming molten carbonate fuel cell (IR-MCFC) are studied by mathematical modeling. Temperature distributions, conversion of methane and compositions of gases are analyzed through mathematical modeling of the reformer and the cell. In the reformer, the methane-reforming reaction and the water-gas shift reaction occur simultaneously and the conversion of methane to hydrogen, calculated including the thermodynamic equilibrium of the reaction, reaches 99%. Additionally, the endothermic-reforming reaction contributes to a uniform temperature distribution. The voltage and the power of the IR-MCFC are similar to those of an external-reforming molten carbonate fuel cell (ER-MCFC), when the compositions at the inlet of the ER-MCFC are set as those at the outlet of the reformer in IR-MCFC. As the molar ratio of methane to water-gas decreases at a fixed total flow rate, the working voltage decreases.