batterydata/paper-abstracts huggingface dataset:
Although with a large capacity, TiNb2O7 as an anode material of lithium-ion batteries suffers from a poor rate capability. To solve this challenge, nano-TiNb2O7 and its carbon nanotube (CNT) nanocomposites were prepared by direct hydrolysis of TiNb2O7/CNTs suspension followed by calcination in air and N2, respectively. The TiNb2O7 nanoparticles in the composites have a Ti2Nb10O29-type crystal structure with O2− vacancies and lower-valence cations, leading to improved Li+-ion diffusion coefficient and increased electronic conductivity in TiNb2O7. The evenly distributed CNTs have good contact with the TiNb2O7 particles, thereby reducing their particle sizes and improving the electrical conduction. As a result of these improvements, the nanocomposites present outstanding electrochemical performances. For example, it delivers a large reversible capacity (346 mAh g−1 at 0.1 C) and a prominent rate capability (still 163 mAh g−1 at the ultra-large current rate of 30 C). Exceptional cyclic stability is also demonstrated with over 100 cycles at 10 C with large capacity retention of 97.6%. These results reveal that the nano-TiNb2O7/CNTs composites can be a promising anode material for lithium-ion batteries of electric vehicles.
The polymer electrolytes based on a novel poly((4-vinylbenzyl)trimethylammonium bis(trifluoromethanesulfonylimide)) polymeric ionic liquid (PIL) as polymer host and containing DEME-TFSI ionic liquid, LiTFSI salt and nano silica are prepared. The polymer electrolyte is chemically stable even at a higher temperature of 60°C in contact with lithium anode. Particularly, the electrolyte exhibits high lithium ion conductivity, wide electrochemical stability window and good lithium stripping/plating performance. When the IL content reaches 60% (the weight ratio of DEME-TFSI/PIL), the PIL electrolyte presents a higher ionic conductivity, and it is 7.58×10−4 S cm−1 at 60°C. Preliminary battery tests show that Li/LiFePO4 cells with the PIL electrolytes are capable to deliver above 130 mAh g−1 at 60°C with very good capacity retention.
Meeting the world's energy needs requires the collective efforts of many different actors across a range of technologies and approaches. In this Feature, ten leading experts in energy research share their vision of the challenges their respective fields must address in the coming decades.
A design of an Instantaneous High Power Supply System (IHPSS) with a power distribution management (PDM) for portable military devices is newly addressed. The system includes a power board and a hybrid battery that can not only supply instantaneous high power but also maintain stable operation at critical low temperature (−30 °C). The power leakage and battery overcharge are effectively prevented by the optimal PDM. The performance of the proposed system under the required pulse loads and the operating conditions of a Korean Advanced Combat Rifle employed in the battlefield is modeled with simulations and verified experimentally. The system with the IHPSS charged the fuse setter with 1.7 times higher voltage (8.6 V) than the one without (5.4 V) under the pulse discharging rate (1 A at 0.5 duty, 1 ms) for 500 ms.
The approach of carbothermal reduction was employed to prepare the micro-sized Sn x SbNi composites used as anode material for rechargeable lithium-ion batteries. The synthesized spherical Sn x SbNi particles show a loose micro-sized structure and a multi-phase composition. The effect of Sn content in Sn x SbNi on the electrochemical properties of the Sn x SbNi composite anode was investigated. Increasing the amount of tin in Sn x SbNi composite leads to an increase in the reversible discharge capacity, however, excessive introduction of Sn into Sn x SbNi alloy will cause the fast capacity decline of electrode. Sn2SbNi alloy provides a reversible specific capacity over 660mAhg−1 and an initial capacity loss of 120mAhg−1 with an excellent cycleability. The low initial capacity loss is attributable to the large particle size of Sn x SbNi powders, while the excellent cycling stability is ascribed to the loose particle structural characteristics and multi-phase features. The former could accommodate the volume change of electrode, while the latter will result in a stepwise lithiation/delithiation behavior and thus a smooth volume change of electrode in cycles.
Ether-based solid polymer electrolyte (SPE) is one of the most well-known lithium ion conductors. Unlike the other inorganic electrolytes, SPE exhibits advantages of flexibility and large-area production, enabling low cost production of large size batteries. However, because the ether group is oxidized at 4 V versus Li/Li+ cathode, and due to its high irreversibility with the carbon anode, ether-based SPE was believed to be inapplicable to 4 V class lithium-ion batteries with carbon anode. Here we report a remarkably stable SPE in combination with a 4 V class cathode and carbon anode achieved by the proper design at the interface. The introduced boron-based lithium salt prohibits further oxidation of SPE at the cathode interface. The surface modification of graphite by the annealing of polyvinyl chloride mostly prohibits the continuous consumption of lithium at the graphite anode. Using above interface design, we achieved 60% capacity retention after 5400 cycles. The proposed battery provides a possible approach for realizing flammable electrolyte-free lithium-ion batteries, which achieve innovative safety improvements of large format battery systems for stationary use.
Silicon which has a theoretical capacity around 3500mAhg−1 and low insertion/deinsertion potentials is one of the most promising candidates to replace graphite as a negative electrode in lithium-ion batteries. Electrochemical performances of Si electrodes are highly dependent on the quality of the SEI. Therefore, the effect of an electrolyte additive, the vinylene carbonate (VC) on electrochemical performances was investigated on sputtered silicon thin films which constitute a simple system (avoiding the use of binders or any conducting additive material). The addition of only 2% of VC significantly improves the capacity retention as well as the coulombic efficiency leading to a capacity retention of 84% after 500 cycles and a coulombic efficiency around 99.5%. To explain the behaviour differences, thorough electrochemical analyses (capacity, coulombic efficiency, polarization at half charge…) combined with scanning electron and atomic force microscopies were carried out. Some correlations have been established between the electrochemical performances and the morphology evolution of the electrode. Thus, VC limits the formation of cracks induced by repeated expansion/contraction cycles and the liquid electrolyte/electrode interactions. In addition, the mechanical pressure locally applied to the thin film allows to maintain a dense morphology and hence has a beneficial effect, too. These two key parameters limit the deterioration of the electrode over cycles.
Polymer electrolyte membrane fuel cells are proving to be a clean and efficient source of energy. Nowadays, extensive research efforts are being focused on bringing this technology to everyday use. An important aspect when integrating fuel cells in practical applications is their ability to respond to load demand. With respect to this, due to their complex internal dynamics, fuel cells belong to the group of more slowly responding sources. In order to make them more generally applicative they are often connected with a battery or a super-capacitor via a power converter to form a hybrid power source. A control algorithm, designed for such a system, represents an interesting challenge: it has to adapt to varying working conditions and operate optimally in terms of efficiency and reliability, while minimizing any impacts on the degradation of the components. Here, we present an approach using supervisory control automaton that switches between the system's operational modes and sets the references for the lower-level control loops. The evaluation of the efficiency and degradation is carried out in a simulation using a model of the widely used 1.2-kW Ballard Nexa power module.
The in vitro micronucleus test is currently used as a screening assay during the early stages of drug development by pharmaceutical companies to identify chemicals likely to produce positive outcomes in the in vitro chromosome aberration assay. For several reasons the assay is being considered as an alternative to the aberration assay—it requires less laboratory time, less material and less training. However, the current screening protocols are not rigorous enough to fully satisfy concerns about genotoxic safety. Using a protocol previously developed by testing 16 chemicals, this manuscript contributes to the validation of the protocol using 10 additional chemicals. Furthermore, conclusions drawn from the developmental effort regarding the need for an extended exposure in the absence of metabolic activation, the number of cells to be counted, and the preferred statistical procedure for the assay are re-examined. The recommended, validated protocol utilizes cytochalasin B and 4h exposures in the presence and in the absence of metabolic activation, specifies the need to test to a relative survival rate of approximately 50%, requires the counting of 2000 binucleated cells per treatment concentration, and employs a trend test for statistical analysis of the data.
Degradation phenomena and inference of their underlying mechanisms during 2C cycle aging in a cell design comprising {LiMn1/3Ni1/3Co1/3O2 +LiMn2O4} composite positive electrode are studied and reported in this work. We describe how aging phenomena in the cells were studied and incremental capacity analysis applied to infer cell degradation mechanisms in the cycle aging process. Two stages of degradation were observed in the life cycle under this aging regime. In the first stage, we conclude that loss of lithium inventory was the cause of capacity fade. As a result of such parasitic loss, the cell further suffered from loss of active materials in the second stage, in which the positive electrode kinetics was hampered and the capacity loss accelerated.
In Taiwan, the government considers the zero-emission scooters to be a sustainable form of transport like walking, cycling and public transport, which play a vital role to support sustainable urban mobility. Therefore, the development of zero-emission scooters is an important strategy in constructing the sustainable transport network of Taiwan. It is also the government's priorities about the policy of emission-reduction and energy-conservation in the transportation sector. Recently, Taiwan launched a new program for subsidy of purchasing zero-emission scooters, which aimed to shift the petroleum-powered scooters to the electric scooters. The present paper is providing an update review of the promotional programs in developing zero-emission scooters in Taiwan. It introduces the status of the establishment and progress of policy, standards, subsidies to users and manufacturers, practice infrastructure, and technology development. Moreover, the contribution of replacing petrol scooters by zero-emission scooters such as battery-powered electric scooters and fuel cell scooters to reduction in greenhouse gas (GHG) emission and improvement in energy efficiency is evaluated.
Nanoflower-like and nanoparticle spinel Li4Ti5O12 were synthesized by a microwave-assisted hydrothermal (MH) method following calcination. As-prepared Li4Ti5O12 was characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and cyclic voltammetry. The nanoflower-like and nanoparticle Li4Ti5O12 exhibited discharge capacities of 176.7 and 109.8mAhg−1, respectively, for the first cycle, and maintained reversible capacities of 138.4 and 91.7mAhg−1, respectively, at a 1.1 C-rate (200mAg−1) after 100 cycles. The better performance of nanoflower-like Li4Ti5O12 relative to nanoparticle Li4Ti5O12 is attributed to the larger specific surface area and shorter Li+ diffusion path of the former relative to the latter. The MH preparation process is straightforward and fast; thus it shows promise for widespread lithium ion battery applications.
We report micrometre-thick porous Si–Cu anodes that are rapidly co-deposited on Cu current collectors in 1 min. This rapid deposition is realized by heating Si and Cu powders to ∼2000 °C and elevating their vapour pressures, while the porous and amorphous anode structure is realized by keeping the substrates at 100 °C. The films spontaneously form a 2–4.5-μm-thick composition gradient that changes from a Cu-rich region at the bottom to a Si-rich region at the top of the film, because of the higher vapour pressure for Cu than Si. A small addition of 5 wt% Cu to the Si source enhances the cycle performance of the film remarkably in a half-cell test, yielding a gravimetric capacity of 1250 mAh gfilm −1, a volumetric capacity of 1956 mAh cmfilm −3, and an areal capacity of 0.96 mAh cmanode −2 at the 100th cycle. However, excess addition of Cu causes partial Si crystallization in the films, which results in poorer cycle performance. While further improvement is needed, this rapid vapour deposition method yields Si–Cu films with compositional gradients on Cu current collectors in 1 min using inexpensive and safe Si and Cu powder sources, and is attractive for practical Si-based anode fabrication.
A polypyrrole-coated LiV3O8 nanocomposite was prepared as anode material (negative mass) for aqueous rechargeable lithium batteries and characterized by X-ray diffraction, scanning electron microscopy, and electrochemical measurements. Polypyrrole acts as a conducting matrix as well as a coating agent, which held LiV3O8 nanorods inside the particles during the charge/discharge cycles. Results show that the electrochemical performance of the PPy@LiV3O8 nanocomposite is significantly enhanced showing higher capacity and better rate capability as well as better cycling performance compared to pristine LiV3O8.
Schizophrenia typically results in reduced performance on the Wisconsin Card Sorting Test (WCST). In the current study, we used a variety of approaches to examine the role of working memory (WM) in this deficit. One approach was to examine patterns of perseverative and non-perseverative errors. A second approach involved the comparison of the standard WCST to a modified version that used visual cues to reduce demands on WM. A third approach was to quantify the impact of WM demands on performance on a trial by trial basis. Consistent with theories of WM, the schizophrenia group showed increases in both perseverative and non-perseverative errors and differences between individuals with schizophrenia and controls were largest when WM demands were high. The visual cues helped the schizophrenia group overcome the high WM demands of the test, although they did not reduce the impairment in terms of standard scoring procedures. All impairments disappeared, however, after controlling for group differences on a measure of the speed of encoding information in WM. The pattern of results supports the conclusion that WM impairment contributes to poor performance on the WCST in individuals with schizophrenia, with additional evidence that this impairment results from generalized slowing of information processing.
Charcot Neuro-Arthropathy (CN) is one of the more devastating complications of diabetes. To the best of the authors’ knowledge, it appears that no clinical tools based on a systematic review of existing literature have been developed to manage acute CN. Thus, the aim of this paper was to systematically review existing literature and develop an evidence-based clinical pathway for the assessment, diagnosis and management of acute CN in patients with diabetes.
In this work we have demonstrated how to prepare a novel gel polymer electrolyte (GPE) with remarkable adhesive characteristics by combining a synthesized poly(ionic liquid) consisting of poly(1-vinyl-3-propylimidazolium bis(fluorosulfonyl)imide) (poly(VPIFSI)) and a commercial ionic liquid: 1-ethyl-3-methyl imidazolium bis(fluorosulfonyl)imide (EMIFSI). For this purpose several PIL/IL-GPEs systems (considering the amount of IL) were subjected to electrochemical characterization. The influence of the PIL/IL-GPE (50 wt% of IL) on the properties of a flexible solid state supercapacitor was evaluated using electrochemical impedance spectroscopy, cyclic voltammetry and the galvanostatic charge/discharge technique that allows synchronous measurements of the cell voltage and the potential of the positive and negative electrodes. The influence of the ions on the formation of the electric double layer in the device during cycling employing different conditions and folding angles is discussed. The properties of the adhesive PIL/IL-GPE, such as high conductivity, good interaction between the PIL matrix and the IL liquid phase that prevents any leakage (thereby contributing to greater safety) together with the good adherability and wettability of the gel electrolyte on the electrode surface have produced a device with an improved rate capability and cyclability that undergoes hardly any changes in Csp,cell, Ereal, and Preal of the cell when folded.
We introduce high-performance ultrathin supercapacitor electrodes obtained through the direct covalent-bonding layer-by-layer (LbL) assembly (or ligand-exchange LbL assembly) of amine-functionalized multiwalled carbon nanotubes (CNTs) and transition metal oxide nanoparticles (TMO NPs). The main characteristic of our approach is that the internal interfacial resistance of the electrodes can be minimized through the direct covalent-bonding adsorption of densely packed, high-quality TMO NPs onto CNTs without the aid of nonactive binders or insulating NP ligands, and the resulting volumetric capacitance and cycling stability of the electrodes can be significantly enhanced. For this study, well-defined oleic acid-stabilized pseudocapacitive metal oxide nanoparticles (i.e., OA–Fe3O4 and OA–MnO NPs) prepared in toluene were densely adsorbed onto the CNT layer due to the high affinity between the surface of the TMO NPs and the NH2 moieties of the CNTs. The (CNT/OA–Fe3O4 NP)20 multilayer electrode exhibited a high volumetric capacitance of 248±15Fcm−3 (128±7Fg−1) at 5mVs−1 despite the intrinsically low specific capacitance of the Fe3O4 NPs. Additionally, these film electrodes exhibited high performance stability, maintaining 99.2% of their initial capacitance after 1000 cycles. Furthermore, upon the insertion of OA–MnO NPs with high crystallinity and a high theoretical pseudocapacitance value within multilayers instead of OA–Fe3O4 NPs, the formed electrodes (i.e., (CNT/OA–MnO NP)20 multilayers) exhibited a higher volumetric capacitance of 305±10Fcm−3 (183±5Fg−1) (at a scan rate of 5mVs−1) than other conventional ultrathin supercapacitor electrodes, including manganese oxide or iron oxide NPs.
Cardiac pacing is a proven and effective treatment in the management of many cardiac arrhythmias. Implantable cardiac defibrillators (ICDs) are beneficial for certain patient groups with a history of serious, recurrent ventricular dysrhythmias, with a high risk of sudden cardiac death. Pacemaker devices take many forms and are highly visible on the chest radiograph. The radiographic appearances of ICDs and pacemakers can be similar and are subject to similar complications. The anatomical approach to the implantation, the type of device used and anatomical variations will all affect the appearance of these devices on the chest film. Pacemaker complications identified radiographically include pneumothorax, lead malpositioning, lead displacement or fracture, fracture of outer conductor coil, loose connection between the lead and pacemaker connector block, lack of redundant loops in paediatric patients and excessive manipulation of the device by the patient (Twiddler's syndrome). This pictorial review highlights the role of chest radiography in the diagnosis of post-cardiac pacing and ICD insertion complications, as well as demonstrating the normal appearances of the most frequently implanted devices.
Significant contribution of three-phase boundary for oxygen reduction reaction at a gold disk electrode in hanging meniscus configuration in dimethyl sulfoxide (DMSO) solution was demonstrated. While cyclic voltammograms (CVs) with symmetrical shape representing quasi-reversible kinetics were obtained for oxygen reduction reaction (ORR) at a Au disk electrode in an ordinary configuration when it was fully immersed in an O2 saturated 0.1M tetrabutylammonium hexafluorophosphate (TBAPF6) DMSO solution, asymmetric CVs with enhanced ORR current were obtained at a Au disk electrode in the hanging meniscus configuration. Origin of this feature was investigated at a gold wire electrode, which was immersed partly in the solution, in detail by changing the concentrations of O2 in the gas phase and in solution independently as well as the immersion depth. All the results confirm that the ORR at the three-phase, O2 gas/Au electrode/electrolyte solution, boundary contributes dominantly to the observed current in the hanging meniscus configuration.
In order to ascertain the effect of carbon networks with various dimension on the Li-storage properties of Fe3O4 anode material, three Fe3O4-based nanocomposites with different dimensional carbon networks, including zero-dimensional C/Fe3O4 (0D-C/F), one-dimensional carbon nanotubes/Fe3O4 (1D-CNTs/F) and two-dimensional graphene/Fe3O4 (2D-G/F) nanocomposites, are successfully prepared via precisely controlling the preparation processes and parameters. Their morphology, conductivity, reaction kinetics, and electrochemical properties are discussed in detail. The results show that the addition of 1D-CNTs or 2D-G in the Fe3O4 results in a smaller size of Fe3O4 particles, which shortens the diffusion distance of Li+, and provides a faster electron conduction pathways, as well as the flexible carbon networks will effectively relieve the internal strain during charge and discharge processes. Most importantly, it is revealed that 2D-G/F with the large surface area leads to a faster electrochemical reaction kinetic which is mainly controlled by pseudocapacitive behavior, while the electrochemical reaction kinetic of 1D-CNTs/F is dominated by the slow Li+ insert process. As a result, 2D-G/F shows the best Li-storage performance with a reversible capacity of 1014 mAh g−1 in the first cycle at 0.1 C and even at a high rate of 5 C, the reversible capacity is still 513.5 mAh g−1. Furthermore, after 100 cycles at 0.5 C, it still delivers a reversible capacity of 1125.6 mAh g−1 without capacity decay.
The largest ever study of cognitive function in progressive supranuclear palsy and multiple system atrophy, investigating almost 700 patients, confirms that cognitive dysfunction in these conditions is common and often severe, and can occur early in the course of the disease. Detection, however, depends on an appropriate choice of tests.
When the carbon lattice of the starting material exhibits a curvature as in the case of fullerenes and derivatives, the C–F bonding in the compounds resulting from the fluorination using molecular fluorine is strongly affected and the covalence is significantly weakened. 19F solid state NMR underlines that the higher the curvature the lower the C–F bonding covalence is. The electrochemical discharge potentials of these materials used as electrode in primary lithium batteries can be then tuned according to the curvature, i.e. the diameter of the outer tubes. The potential decreases from 2.9 to 2.3V versus Li+/Li° according to the following classification: SWCNTs, MWCNTs and carbon nanofibres, which can be described as MWCNTs with large diameter due to the high number of walls. The case of highly fluorinated fullerenes is different because several types of bonding coexist and are progressively broken during the electrochemical process at potentials ranged in between 2.0 and 3.6V. The behaviour of fluorinated nanocarbons is also compared to conventional graphite fluorides.