batterydata/paper-abstracts huggingface dataset:
The property determining micro-structure of battery electrodes essentially evolves during drying, appointing it a paramount, yet insufficiently understood processing step in cell manufacturing. The distribution of functional additives such as binder or carbon black throughout the film strongly depends on the drying process. A representative state-of-the-art model system comprising graphite, polymeric binder, carbon black and solvent is investigated to gain an insight into the underlying processes. A new experimental approach is introduced that allows for revelation of the evolution of binder concentration gradients throughout the film during drying. Binder is detected by means of energy-dispersive x-ray spectroscopy (EDS) at the top and bottom surface. Drying kinetics is investigated and the impact of the drying process on electrochemical performance is disclosed. The enrichment of binder at the surface, which is observed while applying high drying rates, is shown to depend on two fundamental processes, namely capillary action and diffusion. The findings reveal characteristic drying stages that provide fundamental insights into film solidification. Based on that, a top-down consolidation mechanism capable of explaining the experimental findings is disclosed. Adhesion of the active layer to the substrate is shown to strongly depend on the local binder concentration in the vicinity of the substrate.
In order to establish an energy system based on intermittent renewable energies it is of the highest importance to develop efficient and commercially viable technologies. In this regard, metal oxides are particularly promising materials to be used in core technologies such as photovoltaics or solar fuel production as well as in energy storage technologies such as batteries. In particular, the production of solar fuels by photo-(electro)chemical methods is currently considered to be the ‘holy grail’ of energy research by some. This high consideration stems from the desirability of converting solar energy directly into chemical bonds and thus into a storable energy carrier. In this regard, the generation of hydrogen via solar water splitting forms a key building block related to this field of research. As a result of its low-cost, environmentally-friendly and earth-abundant nature, ZnO represents a promising material for this application. However, this material possesses some natural limitations, which are currently hindering the use of ZnO for solar water splitting. After considering some general material properties, this review introduces strategies that have been applied to increase the performance of ZnO for photo-(electro)chemical applications. It is discussed how these can help to overcome the most urgent material challenges, such as low visible-light absorption, fast charge carrier recombination and the deterioration of the material due to photo-corrosion. The focus of this short review is therefore on the opportunities associated with different synthetic approaches to manipulate the material's structure, defect-chemistry, opto-electronic properties and chemical stability. Thus nano-structuring, defect-engineering, doping and functional over-coating strategies are analyzed and their potential for the facilitation of ZnO's use for solar water splitting are outlined.
The major deficiency in linking the effects of environmental exposure to children's health is the lack of data on the exposure of children to hazardous environmental pollutants. Accordingly, the present study compared the personal volatile organic compound (VOC) exposure of children from four elementary schools at different proximities to the Daegu Dyeing Industrial Complex (DDIC) and adjacent to different traffic densities. The personal air concentrations of four VOCs (toluene, m,p-xylenes, and o-xylene) were significantly higher for the children attending the school (S1) closest to the boundary of the DDIC compared to the children attending the school (S2) further away. The DDIC was the likely primary cause for the elevated personal air concentrations of the four VOCs in the children attending the school nearest the DDIC. The personal exposure to toluene and methyl tertiary-butyl ether (MTBE) for the children attending the school near a major roadway with a high traffic density was significantly higher than that for the children attending the school near a roadway with a low traffic density. The difference in the breath concentrations was generally similar to the difference in the personal air concentrations among the children from the four schools. In contrast to the children attending schools in low-income areas, the children attending schools in high-income areas exhibited no significant difference in the concentrations of any of the target VOCs in the personal air and breath samples between the children living with and without a smoker in the home.
Carbon coated monoclinic Li3V2(PO4)3 cathode material was prepared by the carbothermal reduction method. Raman scattering showed the amorphous nature of the residual carbon in the material. HRTEM and XPS showed that a small amount of carbon penetrated into the Li3V2(PO4)3 crystallites to form a surface carbon layer with thickness about 5–10nm. The material showed a reversible discharge capacity of 120mAhg−1 (C/4 rate), 115mAhg−1 (1C rate) and 110mAhg−1 (2C rate) in the voltage window of 3.0–4.3V, which kept excellent cycle stability in 300 cycles. The material suffered from capacity loss in the initial ten charge–discharge cycles. The irreversible capacity loss was mainly related to the progressive formation of a solid electrolyte interface (SEI) film which was clearly observed by HRTEM. FTIR analysis showed that the chemical species of the SEI film mainly contained some organic compounds such as ROCO2Li, RCO2Li, and aliphatic, as well as some inorganic compounds such as Li2CO3, Li x PF y or Li x PO y F z . The SEI film tended to be stabilized in the initial several cycles, which led to excellent electrochemical performance during long term cycling.
The lithium metal–Li+ interface was investigated in N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulphonyl)imide room temperature ionic liquid, using impedance simulation, experimental electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The electrolyte contained vinylene carbonate as the solid electrolyte interphase (SEI) forming additive. The Warburg coefficient value obtained from impedance plot deconvolution (A W >10Ωs−1/2) and SEM lithium surface image suggest the SEI layer formation. Therefore, the charge transfer process on lithium reduction and oxidation takes place at the solid Li|SEI interface. Simulation studies show that the typical shape of impedance plots for the Li|Li+ system (reported in the literature) suggests the exchange current density below 10−2 Acm−2. The exchange current density of Li|SEI|Li+ in the ionic liquid electrolyte, obtained from impedance spectra and Tafel plot is between 4.5×10−4 Acm−2 and 3.0×10−4 Acm−2 (Li+ concentration of 0.7moldm−3).
Two dimensional (2D) transition metal oxides and chalcogenides demonstrate a promising performance in sodium-ion batteries (SIBs) application. In this study, we investigated the use of a composite of freeze dried V2O5·nH2O nanosheets and multi-walled carbon nanotube (MWCNT) as a negative electrode material for SIBs. Cyclic voltammetry (CV) results indicated that a reversible sodium-ion insertion/deinsertion into the composite electrode can be obtained in the potential window of 0.1–2.5 V vs. Na+/Na. The composite electrodes delivered sodium storage capacities of 140 and 45 mAh g−1 under applied current densities of 20 and 100 mA g−1, respectively. The pause test during constant current measurement showed a raise in the open circuit potential (OCP) of about 0.46 V, and a charge capacity loss of ∼10%. These values are comparable with those reported for hard carbon electrodes. For comparison, electrodes of freeze dried V2O5·nH2O nanosheets were prepared and tested for SIBs application. The results showed that the MWCNT plays a significant role in the electrochemical performance of the composite material.
Hydrothermal decomposition of permanganate, conducted in a range of pH-controlled solutions (from strongly acidic to strongly basic), is used to prepare manganese dioxides that are well-suited for use as supercapacitor electrode materials. While permanganate is thermodynamically unstable, the kinetics of its decomposition in an aqueous environment are very slow, until the temperature is raised to ∼200°C. Although the resultant materials are relatively crystalline and have low total pore volume, their prominent meso-porosity leads to good electrochemical performance. Best behaviour is obtained for material from permanganate decomposition in 0.01M H2SO4 solution, for which composite electrodes (150μm thick) yield ∼150Fg−1 at 5mVs−1 in a 9M KOH electrolyte.
In contrast to industrial markets based on mass-production of material goods, postindustrial markets hinge on images, experiences, and emotions produced and exchanged on screens and in real life. Because postindustrial markets tend to be highly concentrated and technology-driven, they pose a threat to small businesses and low-skill workers in both advanced industrial economies and the Global South, where a large share of the population makes a living in the informal economy. Using the 2014 World Cup as a case of postindustrial economic activity hinged on spectacle, emotional experience, and intellectual property, I analyze the income-making strategies used by street vendors in São Paulo, Brazil. I show that organizers’ control of fan markets was limited by local conceptions of ownership over national symbols as well as informal workers’ flexible relation to legal norms and enforcement-dodging practices. Circumventing market barriers required risky and sophisticated strategies, however, which were more readily available to the more marginal section of the street vending population.
Polymer nanocomposite gel electrolytes consisting of high molecular weight poly(methyl methacrylate) PMMA–clay nanocomposite, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer, and LiClO4 electrolyte are reported. Montmorillonite clay was ion exchanged with a zwitterionic surfactant (octadecyl dimethyl betaine) and dispersed in methyl methacrylate, which was then polymerized to synthesize PMMA–clay nanocomposites. The nanocomposite was dissolved in a mixture of EC/PC with LiClO4, heated and pressed to obtain polymer gel electrolyte. X-ray diffraction (XRD) of the gels indicated intercalated clay structure with d-spacings of 2.85 and 1.40nm. In the gel containing plasticizer, the clay galleries shrink suggesting intercalation rather than partial exfoliation observed in the PMMA–clay nanocomposite. Ionic conductivity varied slightly and exhibited a maximum value of 8 × 10−4 S/cm at clay content of 1.5wt.%. The activation energy was determined by modeling the conductivity with a Vogel–Tamman–Fulcher expression. The clay layers are primarily trapped inside the polymer matrix. Consequently, the polymer does not interact significantly with LiClO4 electrolyte as shown by FTIR. The presence of the clay increased the glass transition temperature (Tg) of the gel as determined by differential scanning calorimetry. The PMMA nanocomposite gel electrolyte shows a stable lithium interfacial resistance over time, which is a key factor for use in electrochemical applications.
Autism spectrum disorders (ASD) are known to be associated with an inflammatory process related to immune system dysfunction. This study’s aim was to investigate the role of cell-free DNA in chronic inflammatory process in ASD patients.
Many inactive materials have been found to be helpful for improving the electrochemical performance of Co electrode in alkaline rechargeable batteries, including B, P, Si, S, Si3N4, and BN. In this paper we find for the first time that selenium has a similar effect with them. Selenium incorporation is realized through a liquid-reduction method. The obtained Co–Se sample is investigated as the negative electrode material of alkaline rechargeable battery. Experimental results demonstrate that the Co–Se sample electrode shows excellent electrochemical reversibility and considerably high charge–discharge capacity, showing a great potential to enhance the electrochemical performance of Co-based alkaline rechargeable batteries. The electrochemical reaction mechanism and function mechanism of Se are also investigated.
Oxygen reduction has been studied on glassy carbon rotating disc substrates modified by platinum- and gold-coated copper particles. The deposits have been formed by a two-step process, whereby controlled amounts of Cu were electrodeposited onto the substrate and were subsequently coated with a thin Pt or Au layer upon immersion of the Cu/GC electrode into chloroplatinic or chlorolauric acid solutions. The spontaneous surface replacement of Cu by Pt or Au resulted in Pt(Cu)/GC or Au(Cu)/GC electrodes which consisted of dispersed Pt(Cu) or Au(Cu) particles and displayed typical Pt and Au surface electrochemistry. Based on mass transfer-corrected Tafel plots, the oxygen reduction catalytic activity in acid of platinum- and gold-coated copper deposits has been compared to that of bulk Pt and Au respectively.
Speed indicator devices (SIDs) are vehicle activated signs displaying the real-time speeds of passing vehicles. They are part of the array of road safety measures for managing speeds on local authority roads in the United Kingdom. This paper documents an evaluation of the effectiveness of SIDs that was carried out in South London in 2008. SIDs were installed at 10 sites in South London for periods of between one and three weeks. The overall effect of the SIDs being installed was a reduction in vehicle speeds of 1.4mph and a significant reduction in the proportion of vehicles exceeding the speed limit. The research also investigated the distance over which the SIDs are effective and the effect on vehicle speeds once the SID is removed. The results showed that a speed reduction occurred over a distance of up to 400m and that once the SID is removed then, in general, the mean vehicle speeds returned to pre-SID levels by the end of the first week.
Glassy precursors in the Li1+x Ga x Ge2-x P3O12 system are prepared by melting and casting. The glasses are annealed at the crystallization peak temperatures to obtain glass ceramics with Na-superionic conducting structure. The ionic conductivity can be significantly increased by substituting Ge with Ga and Li. The highest ionic conductivity of the glass ceramics is 9.74 × 10−5 S cm−1 at 20 °C. Multiple magic angle spinning nuclear magnetic resonance (MAS NMR) techniques are used to characterize the structural transitions from glasses to their glass ceramic counterparts. 71Ga and 31P MAS NMR spectra have shown that the local structures of the glasses are distinctly modified after crystallization. The second coordinated shells of Ga3+ ions are consisted of phosphorus in both glasses and glass ceramics although their coordination numbers change. The glassy precursors show homonuclear segregations such as P-O-P and Ge-O-Ge linkages. However, the glass ceramics are homogeneous, in which per phosphorus tetrahedron connects with total four Ga and Ge, forming four different phosphorus species (Q0 (4-n)Ge, nGa (n = 0, 1, 2, and 3)). A random distribution model can be used to quantitatively predict the population of every Q0 (4-n)Ge, nGa species, if the compositions are known. A correlation between local structure and ionic conductivity is proposed.
Effect of the AC (alternating current) pulse heating method on battery SoH (state of health) for large laminated power lithium-ion batteries at low temperature is investigated experimentally. Firstly, excitation current frequencies, amplitudes, and voltage limitations on cell temperature evolution are studied. High current amplitudes facilitate the heat accumulation and temperature rise. Low frequency region serves as a good innovation to heat the battery because of the large impedance. Wide voltage limitations also enjoy better temperature evolution owing to the less current modulation, but the temperature difference originated from various voltage limitations attenuates due to the decrement of impedance resulting from the temperature rise. Experiments with the thermocouple-embedded cell manifest good temperature homogeneity between the battery surface and interior during the AC heating process. Secondly, the cell capacity, Direct Current resistance and Electrochemical Impedance Spectroscopy are all calibrated to assess the battery SoH after the hundreds of AC pulse heating cycles. Also, all cells are disassembled to investigate the battery internal morphology with the employment of Scanning Electron Microscope and Energy-Dispersive x-ray Spectroscopy techniques. The results indicate that the AC heating method does not aggravate the cell degradation even in the low frequency range (0.5 Hz) under the normal voltage protection limitation.
The photogalvanic effect of photosensitizer – reductant pair, Toluidine Blue–Arabinose and Malachite Green–Arabinose have been studied in presence of anionic surfactant NaLS (sodium lauryl sulphate) and a tentative mechanism has been proposed for the cell reaction. The photopotential (ΔV) and photocurrent (i sc) were obtained 813.0mV and 60.0μA in Toluidine Blue system and 348.0mV and 36.0μA in Malachite Green system. The conversion efficiency and storage capacity of the developed cells were found to be 0.1448% and 123.0min, respectively with Toluidine Blue system and 0.0590% and 32.0min, respectively with Malachite Green system.
Accumulating evidence indicates that disruption of galanin signaling is associated with neuropsychiatric disease, but the precise functions of this neuropeptide remain largely unresolved due to lack of tools for experimentally disrupting its transmission in a cell type-specific manner. To examine the function of galanin in the noradrenergic system, we generated and crossed two novel knock-in mouse lines to create animals lacking galanin specifically in noradrenergic neurons (GalcKO–Dbh). We observed reduced levels of galanin peptide in pons, hippocampus, and prefrontal cortex of GalcKO–Dbh mice, indicating that noradrenergic neurons are a significant source of galanin to those brain regions, while midbrain and hypothalamic galanin levels were comparable to littermate controls. In these same brain regions, we observed no change in levels of norepinephrine or its major metabolite at baseline or after an acute stressor, suggesting that loss of galanin does not affect noradrenergic synthesis or turnover. GalcKO–Dbh mice had normal performance in tests of depression, learning, and motor-related behavior, but had an altered response in some anxiety-related tasks. Specifically, GalcKO–Dbh mice showed increased marble and shock probe burying and had a reduced latency to eat in a novel environment, indicative of a more proactive coping strategy. Together, these findings indicate that noradrenergic neurons provide a significant source of galanin to discrete brain areas, and noradrenergic-specific galanin opposes adaptive coping responses.
Alarming carbon dioxide emissions and its detrimental environmental impacts (e.g. climate change and global warming) are the major consequences of the undue reliance of the modern civilization on fossil fuels. Long-term solutions to address these issues are based on developing sustainable alternatives for the human energy thirst. However, the versatilities offered by the carbonaceous fuels have still preserved their popularity as the main source of energy for a wide variety of applications. After decades of practicing conventional carbon capture and storage, researchers believe the ultimate solution of realistically facing with CO2 sequestration problem is the chemical conversion of carbon dioxide to valuable products. However, substantial development of state-of-the-art materials remains the major bottleneck of such technologies. Graphene, as the rising star of the materials world in 21st century, offers game-changing prospects towards a more sustainable future for fossil-fuel-based economies. This two-dimensional planar sheet of sp2-bonded carbon atoms is the most widely studied nanomaterial since its discovery in 2004. Here we aim to highlight various aspects of graphene research in carbon dioxide capture and conversion from materials viewpoint. After presenting an overview of the most common and effective synthesis and doping/functionalization methods, the application of graphene and its derivatives in CO2 capture and conversion is discussed in detail. Catalytic, electrocatalytic and photoelectrocatalytic use of graphene-based compounds could potentially revolutionize some of the current techniques for CO2 transformation to valuable chemical commodities. CO2 to graphene conversion pathways are also covered extensively in this review paper as another intriguing relation of graphene with CO2.
We assessed the impact of unilateral epileptic foci in benign idiopathic partial epilepsy of childhood with rolandic discharges (BECT) on performance and hemispheric specialization in lateralized cognitive functions. Six children with BECT with a left-sided focus (BECT-L), 6 children with BECT with a right-sided focus (BECT-R), and 12 control children were tested in verbal, visual–spatial, and visual-attention tasks, with visual hemifield presentation. Children with BECT-R were impaired in the visual–spatial task relative to those with BECT-L, and the typical left-hemisphere (LH) advantage was not reported in the verbal task in children with BECT-L. Additionally, the classic global superiority effect was lacking in children with BECT-R, which may be due to impaired performance of the right hemisphere specialized in global (vs local)-level processing. These data argue for the deleterious effect of epileptic discharges per se on cognitive functions in the developing brain, and the decisive role of epileptic focus lateralization in specific cognitive impairments and hemispheric specialization.
The deployment of wireless sensor networks in many application areas requires self-organization of the network nodes into clusters. Clustering is a network management technique, since it creates a hierarchical structure over a flat network. Quite a lot of node clustering techniques have appeared in the literature, and roughly fall into two families: those based on the construction of a dominating set and those which are based solely on energy considerations. The former family suffers from the fact that only a small subset of the network nodes are responsible for relaying the messages, and thus cause rapid consumption of the energy of these nodes. The latter family uses the residual energy of each node in order to decide about whether it will elect itself as a leader of a cluster or not. This family’s methods ignore topological features of the nodes and are used in combination with the methods of the former family. We propose an energy-efficient distributed clustering protocol for wireless sensor networks, based on a metric for characterizing the significance of a node, w.r.t. its contribution in relaying messages. The protocol achieves small communication complexity and linear computation complexity. Experimental results attest that the protocol improves network longevity.