batterydata/paper-abstracts huggingface dataset:
The influence the composition of the cathode has on its structure and electrochemical performance was investigated for a Nafion content spanning from 10 to 70wt.%. The cathodes were formed on a Nafion membrane by the spray method and using 20wt.% Pt on Vulcan (E-TEK). Materials characterisation (SEM, STEM, gas and mercury porosimetry, electron conductivity) and electrochemical characterisation (steady-state polarisation curve, impedance spectroscopy in O2 and current-pulse measurements in N2) were performed. The impedance spectra were analysed using our dynamic agglomerate model. The results indicate that the agglomerate model is valid until a Nafion content of about 45wt.%. Pt/C and Nafion are homogeneously mixed for any composition and no Nafion film was observed. The cathodes containing 36–43wt.% Nafion display a single or double Tafel slope behaviour ascribed to diffusion limitations in the agglomerates. At larger Nafion content, the agglomerate model can describe the curves only by assuming a diffusion coefficient 3–4 decades smaller than that of gases. At such compositions, the porosity was only 10%. These results were interpreted as a blocking of the pores and a non-percolating pore system for too large Nafion contents.
Publisher Summary The development of the concept of model-based systems was an answer to the limitations of rule-based expert systems, which base problem solving (e.g., diagnosis) on a representation of experiential knowledge in a domain. These limitations are not due to the syntactic form of representing knowledge (rules), but they result from the nature of the represented knowledge termed “empirical associations” in the pioneering paper or “shallow knowledge” in others. This chapter discusses the key ideas of selected solutions with some formalization and, perhaps, some hints on a possible implementation. In discusses solutions that address the important requirements of the application context in a principled and general way over approaches that are heavily influenced by specific features of a particular application domain or that fail to reflect essential conditions of a real-world task. Diagnosis is only a step toward the real goal, which is restoring the functionality of a disturbed system. To be effective in the framework of consistency-based problem solving, completeness matters—that is, its ability to detect all existing (or relevant) inconsistencies.
This paper reviews existing vehicle environmental rating methodologies worldwide and focuses on how these methodologies deal with alternative vehicle technologies (plug-in vehicles, hybrid vehicles, and fuel cell vehicles) and emissions of greenhouse gases (CO2, N2O, and CH4) and pollutants (NO x , VOC, CO, SO x , PM10 and PM2.5) derived from embodied materials life cycle. United States, Mexico, Europe and Australia have public access data and websites with top 10 rankings. The ways the scores are calculated for each vehicle have differences in what regards the considered boundaries for the emissions analysis. In Europe, there is still not a unique rating methodology or ranking system, e.g., Belgium, Germany and United Kingdom have their specific scoring schemes. Multilinear regression models were developed as an attempt to estimate the vehicle embodied emissions as a function of vehicle lifecycle mileage, electricity mix, vehicle mass, battery mass and fuel cell power to cope with different production regions and different alternative vehicle technologies. The regression models were validated against Volkswagen life cycle assessments (LCAs), and compared against American Council for an Energy Efficient Economy (ACEEE) – Green Book linear functions for material assessment and UK 12 material dataset for materials assessment. The developed models proved to be useful in applications related to rating methodologies using life-cycle concepts, with good reliability for comparisons considering the complexity of processes involved in vehicle materials life-cycle assessment.
Population response to anthropogenic activities will be influenced by prior adaptation to environmental conditions. We tested how parasite-resistant and -susceptible strains of the freshwater snail, Biomphalaria glabrata, responded to cadmium and elevated temperature challenges after having been exposed to low-level cadmium continuously for multiple generations. Snails exposed to cadmium for three generations were removed for the fourth generation, and challenged in the fifth generation with (1) chronic cadmium exposure over the entire life cycle; (2) lethal cadmium exposure of adults; and (3) elevated temperature challenge of adults. The parasite susceptible NMRI strain is more cadmium tolerant than the parasite resistant BS90 strain and remained more tolerant than BS90 throughout this study. Additionally, NMRI exhibited greater adaptive capacity for cadmium than BS90 and became more tolerant of both chronic and lethal cadmium challenges, while BS90 became more tolerant of lethal cadmium challenge only. Fitness costs, reflected in population growth rate, were not apparent in fifth generation snails maintained in control conditions. However, costs were latent and expressed as decreased tolerance to a secondarily imposed temperature stress. Adaptation to prior selection pressures can influence subsequent adaptation to anthropogenic stresses and may have associated costs that reduce fitness in novel environments.
Background Fever in the postoperative period frequently results in a battery of diagnostic tests in search of an etiology. We sought to evaluate the incidence and utility of extensive postoperative fever evaluations in a teaching hospital setting. Materials and Methods Prospective observational study of all adult patients undergoing in-patient general surgical procedures during a 13-mo period. Patients experiencing an early postoperative fever (>100.4° F in the first 72 h) had data collected on their evaluation, the yield of the diagnostic studies, and whether an infectious diagnosis was made. Results Of 1032 surgical procedures, 245 (23.7%) patients experienced an early postoperative fever. One hundred patients (9.7%) underwent documented fever evaluation. Thirty-five (35%) had blood cultures with no positive results among elective surgery patients. Forty-six patients (46%) had urine cultures sent, of which four infections were diagnosed (8.9%). Fifty chest radiographs were performed, but the diagnosis of pneumonia was made by only three (6.0%). Ultimately, 18 febrile patients (18%) were diagnosed with an infectious source, in nine of these patients the physical exam and clinical picture accurately diagnosed the infection without need for further testing. Conclusion Early postoperative fever is a common event and rarely caused by an infection. A brief bedside evaluation has the highest yield for determining the fever etiology, and extensive evaluations with cultures and chest imaging have little to no benefit in patients admitted for elective surgery.
Layer-structured Zr doped Li[Ni1/3Co1/3Mn1−x/3Zr x/3]O2 (0≤ x ≤0.05) were synthesized via slurry spray drying method. The powders were characterized by XRD, SEM and galvanostatic charge/discharge tests. The products remained single-phase within the range of 0≤ x ≤0.03. The charge and discharge cycling of the cells showed that Zr doping enhanced cycle life compared to the bare one, while did not cause the reduction of the discharge capacity of Li[Ni1/3Co1/3Mn1/3]O2. The unchanged peak shape in the differential capacity versus voltage curve suggested that the Zr had the effect to stabilize the structure during cycling. More interestingly, the rate capability was greatly improved. The sample with x =0.01 presented a capacity of 160.2mAhg−1 at current density of 640mAg−1(4C), corresponding to 92.4% of its capacity at 32mAg−1(0.2C). The favorable performance of the doped sample could be attributed to its increased lattice parameter.
For future vehicles, the 42-V power system offers a variety of new applications, from the capability to sustain increased comfort loads up to mild hybridization. To meet these requirements, considerable progress is needed for the lead–acid system to achieve reasonable lifetime and reliability in service. In addition to cycle-life improvement at partial state-of-charge, both a state-of-health indication and a battery management system with sophisticated algorithms to achieve sufficient cycle-life are required. Due to the inherently lower cost of lead–acid, only a slow migration towards more advanced battery systems is anticipated. Some applications for nickel–metal-hydride and Li-ion batteries are discussed.
Active-emphatic listening is active listening that focuses on empathy. The Active-Empathic Listening Scale (AELS) is a self-report scale comprising three dimensions: sensing, processing, and responding. However, translated versions are not available for languages used in Asian countries, such as Japanese. The aim of the present study was to demonstrate and report on the reliability and validity of the Japanese version of the AELS.
Surface exothermic chemical reaction was amplified by the carbon nanotube film on a polymer substrate. Heat was transferred along the nanotubes with high thermal conductivity/low heat capacity and fed back to the reactants, leading to the amplification of reaction rate, while suppressing perpendicular heat transfer to the thermally insulating substrate.
We fabricated a highly conductive pyrolytic carbon layer that penetrates into nanoporous alumina channels and that strongly adheres to an aluminum (Al) current collector in order to reduce the contact resistance at the interface between a carbon active material and an Al current collector. The fabrication method includes the following processes: (i) Al anodization, (ii) alumina etching, (iii) nickel seed layer deposition on the alumina surface, and (iv) chemical vapor deposition of pyrolytic carbon grown by the catalytic nickel layer. From SEM and EDX analyses, we confirmed that the pyrolytic carbon could be uniformly placed into an alumina nanoporous template on the Al substrate. Based on measurements of the transverse resistance and electrochemical capacitor tests, the fabricated composite layer of pyrolytic carbon and nanoporous alumina significantly reduced contact resistance of Al/carbon interface due to the highly conductive pyrolytic carbon formed through the nanoporous alumina on the Al surface.
The zinc regenerative fuel cell (ZRFC) developed by the former Metallic Power Inc. over the period from 1998 to 2004 is described. The component technologies and engineering solutions for various technical issues are discussed in relation to their functionality in the system. The system was designed to serve as a source of backup emergency power for remote or difficult to access cell phone towers during periods when the main power was interrupted. It contained a 12 cell stack providing 1.8kW, a separate fuel tank containing zinc pellet fuel and electrolyte, and a zinc electrolyzer to regenerate the zinc pellets during standby periods. Offsite commissioning and testing of the system was successfully performed. The intellectual property of the ZRFC technology is now owned by Teck Cominco Metals Ltd.
is Development Engineer for Fibre-reinforced Polymers and Advanced Development of BEVs at Audi AG in Ingolstadt (Germany).
Commercially available low cost exfoliated graphite (EG, nominal diameter 130μm) was used as a conductive substrate for electrochemical capacitor of hydrated Mn(IV) oxide, MnO2·nH2O. The MnO2·nH2O–EG composites were prepared by addition of EG to potassium permanganate solution, followed by 1h stirring and then slow addition of manganese(II) acetate solution. By this procedure submicrometer or smaller sized MnO2·nH2O particles having mesopores of 6–12nm in diameter were formed on the graphite sheets of EG. Although EG alone showed only about 2Fg−1, the composites showed good rectangular cyclic voltammograms at 2–20mVs−1 in 1molL−1 Na2SO4. The capacitance per net amount of MnO2 increased proportionally with EG content, that is, utilization ratio of MnO2 increased with EG content. The composites of MnO2·nH2O and smaller diameter of EG (nominal diameter 45μm) or artificial graphite powder (average diameter 3.7μm) showed fairly good performance at 2mVs−1, but with increasing potential scan rate the rectangular shape was distorted and capacitance decreased drastically. The results implies that sheet-like structure is more effective than small particles as conductive materials, when the formation procedure of composite is the same. Large sized EG may be a promising conductive material for electrochemical capacitors.
Substantive advances in clinical epileptology may be realized through the judicious use of real-time automated seizure detection, quantification, warning, and delivery of therapy in subjects with pharmacoresistant seizures. Materialization of these objectives is likely to elevate epileptology to the level of a mature clinical science.
This study aims to investigate the power potential of Li-ion batteries using a hydrothermal process to synthesize nanoscale Nb–TiO2 with high surface area. By substituting Nb into anatase TiO2, the rate capability of Li-ion batteries is improved with the formation of nanoplate Nb–TiO2 containing (001) facets and NbOx species. In addition, the high solubility of Nb promotes the transformation of TiO2 from hollow-like to plate-like morphology, accelerating the Li-ion surface transportation over a large contact area. With respect to rate capability, Nb–TiO2 displays a high capacity of 220 mAh g−1 at 0.5C and retains 127 mAh g−1 at 10C. Additionally, the cyclability test exhibits less degradation after 10,000 cycles. In order to investigate the mechanisms of capability improvement, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) are applied to measure the Li-ion diffusivity and surface charge-transfer resistance. The results demonstrate that both Li-ion diffusivity and surface charge-transfer ability are enhanced, leading to pseudocapacitance. Thus, it can be concluded that nanoplate Nb–TiO2 exhibits superior rate capability by the improvement of pseudocapacitance. This study derives a novel process to synthesize nanoplate TiO2 and should provide a potential approach for industrial fabrication of high power Li-ion batteries.
The graphite plate is easily suffered from corosion because of CO2 evolution when it acts as the positive electrode for vanadium redox flow battery. The aim is to obtain the initial potential for gas evolution on a positive graphite electrode in 2moldm−3 H2SO4 +2moldm−3 VOSO4 solution. The effects of polarization potential, operating temperature and polarization time on extent of graphite corrosion are investigated by potentiodynamic and potentiostatic techniques. The surface characteristics of graphite electrode before and after corrosion are examined by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The results show that the gas begins to evolve on the graphite electrode when the anodic polarization potential is higher than 1.60V vs saturated calomel electrode at 20°C. The CO2 evolution on the graphite electrode can lead to intergranular corrosion of the graphite when the polarization potential reaches 1.75V. In addition, the functional groups of COOH and CO introduced on the surface of graphite electrode during corrosion can catalyze the formation of CO2, therefore, accelerates the corrosion rate of graphite electrode.
To enhance the structural stability and improve the poor electrochemical reaction kinetics of anodes for sodium ion batteries (SIBs), we develop a novel strategy to couple NiCoP bimetallic phosphide nanoparticles with alkali-induced 3D interconnected crinkled porous Ti3C2 MXenes as anodes for high-performance SIBs. The interconnected 3D Ti3C2 crinkled architectures can establish a 3D conductive network, abundant open pores and large surface area, which provides a 3D conductive highway and unblocked channels for a rapid charge transfer process and for electrolyte storage, and makes fully close contact between the electrode and electrolyte. The unique MXene structure can effectively tolerate volume expansion and prevent aggregation and pulverization of NiCoP nanoparticles during Na+ insertion/extraction processes. The NiCoP bimetallic phosphide possesses richer redox reaction sites, higher electrical conductivity and low charge transfer impedance. The synergistic effect between the components of NiCoP and MXene Ti3C2 with high structural stability and electrochemical activity leads to excellent electrochemical performance, retaining a specific capacity of 261.7 mA h g−1 at a current density of 1 A g−1 for 2000 cycles. The present strategy of an in situ phosphization route and coupling phosphides with crinkled 3D Ti3C2 can be extended to other novel electrodes for high-performance energy storage devices.
The electrochemical behaviour and electrical performance are investigated for a series of lithium-sulfur (Li-S) cells in which the electrolyte solutions are organic solvent-ionic liquid mixtures that are based on the 1-butyl-1-methylpyrrolidinium (C4mpyr) cation with a range of anions. In each case, performance is compared with cells that are based on a standard mixed-ether organic electrolyte. The capacity of cells assembled with electrolytes containing 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate (C4mpyr-FAP), 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (C4mpyr-OTf), or 1-butyl-1-methylpyrrolidinium tricyanomethanide (C4mpyr-TCM) decline rapidly due to low conductivity, high polysulfide solubility and side reaction of electrolyte with electrodes, respectively. Our results confirm that polysulfide solubility is strongly controlled by the anion of the ionic liquid and verify that not all ionic liquids decrease polysulfide solubility. In agreement with previous reports, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (C4mpyr-TFSI) shows the best compatibility in Li-S batteries and has a higher coulombic efficiency of greater than 99% over 100 cycles. Furthermore, impedance spectroscopy confirms that electrolyte composition influences the SEI layer formed on the lithium anode and its subsequent impedance.
To improve the charge/discharge properties of a rechargeable Li-O2 battery (LAB), we synthesized a new air-electrode catalyst composed of MnO2 nanosheets (Mn-NSs) and Ketjen Black (KB), i.e., a KB-comp. Mn-NS catalyst. The composite catalyst was synthesized by electrostatically restacking the nanomaterials in a colloidal solution with Li+ and its electro-catalytic activity as an air-electrode for a LAB test cell was evaluated. The KB-comp. Mn-NS catalyst exhibited excellent performance, especially for oxidation of Li2O2 deposited on the surface of the air-electrode during the charging process, which led to enhanced reversibility of the Li2O2 deposition/decomposition reaction during the discharging/charge cycles. Evidence of these reactions was investigated and confirmed by X-ray diffraction analysis and scanning electron microscopy-energy dispersive X-ray spectroscopy. The Li2O2 was deposited and decomposed more homogeneously at the air-electrode with the KB-comp. Mn-NS catalyst than that with only KB. Consequently, the composite catalyst significantly reduced the overpotential and improved the cycleability up to the 27th cycle, even at 0.40mA.
The inherent uncertainty of the wind is a major impediment for successful implementation of wind based power generation technology. A methodology has been proposed in this paper to incorporate wind speed uncertainty in sizing wind-battery system for isolated applications. The uncertainty associated with the wind speed is incorporated using chance constraint programming approach. For a pre-specified reliability requirement, a deterministic equivalent energy balance equation may be derived from the chance constraint that allows time series simulation of the entire system. This results in a generation of the entire set of feasible design options, satisfying different system level constraints, on a battery capacity vs. generator rating diagram, also known as the design space. The proposed methodology highlights the trade-offs between the wind turbine rating, rotor diameter and the battery size for a given reliability of power supply. The optimum configuration is chosen on the basis of the minimum cost of energy (US$/kWh). It is shown with the help of illustrative examples that the proposed methodology is generic and flexible to incorporate alternate sub-component models.
Nanoporous carbon nanofibers (CNFs) are produced by incorporating tetraethyl orthosilicate (TEOS) into polyacrylonitrile (PAN) via electrospinning, and their electrochemical properties are investigated as an electrode in supercapacitors. TEOS is used as a pore generator in the PAN-based precursor for the CNFs with stabilized Si-related functional structures. The microstructures (e.g., nanometer-size diameters, high specific surface areas, narrow pore size distributions, and tunable porosities) and some of the surface functionalities of the CNFs are affected by the TEOS concentration. The electrode with these characteristics demonstrates better supercapacitor performance in terms of capacitance, energy, and power efficiency, which is attributed to the synergistic effect between the double-layer capacitance and the pseudo-capacitive effect.
The aim of this study is to design a controller, based on model predictive control (MPC), to smooth the wind power output, which is generated from a wind farm, and subject to a variety of constraints on the system model. In order to employ the model predictive controller, we propose a wind power prediction system, which is used by the controller within its predictive optimization. The proposed controller is capable of smoothing wind power by utilizing inputs from our prediction system, and optimizes the maximum ramp rate requirement and also the state of the charge of the battery under practical constraints. The proposed prediction model is capable of predicting the wind power several steps ahead which is used in the optimization part of the controller. We illustrate the effectiveness of the proposed controller with a simulation example, employing real wind farm data under a variety of hard constraints.
The effect of propylene carbonate (PC)-Li+ solvation structures on graphite exfoliation was investigated over a range of concentrations of PC-based electrolytes. At low concentrations of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) in PC (1.3M and 2.1M), the graphite anode was exfoliated. However, the graphite exfoliation could be effectively suppressed when the concentrations of dissolved LiTFSI were increased to 2.5M and 3.3M. The results of spectroscopic analyses and density functional theory (DFT) calculations revealed that electrochemical exfoliation of the graphite anode is closely associated with a special spatial configuration of Li+-(PC)n (1≤n≤4) solvation structures at various Li-salt concentrations and corresponding solid electrolyte interface (SEI) film formation mechanisms. When the concentration of LiTFSI increased from 1.3 to 3.3M, the spatial configuration of Li+-(PC)n (1≤n≤4) solvation gradually changed from a tetrahedron (occupied space of 10.19Å) to planar (occupied space of 3.05Å), which reduced the structure change for co-intercalation into the graphite interlayers of Li+-(PC)n (1≤n≤4) solvates. Meanwhile, the affinity between Li+-(PC)n (1≤n≤4) solvation cations and TFSI− anions was increased, leading to the significant contribution of TFSI− anions to SEI formation on the surface of graphite. Additionally, Al corrosion was not of concern in concentrated LiTFSI electrolyte. The 3.3M LiTFSI/PC concentrated electrolyte exhibits promising electrochemical performance in graphite||LiNi1/3Co1/3Mn1/3O2 full cells.