batterydata/paper-abstracts huggingface dataset:
MnO microspheres with and without carbon coating are prepared as anode materials for lithium ion batteries. The MnO microsphere material shows a reversible capacity of 800mAhg−1 and an initial efficiency of 71%. It can deliver 600mAhg−1 at a rate of 400mAg−1. Results of Mn K-edge X-ray absorption near-edge structure (XANES) spectra and extended X-ray absorption fine structure (EXAFS) confirm further the conversion reaction mechanism, indicate that pristine MnO is reduced to Mn0 after discharging to 0V and part of reduced Mn0 is not oxidized to Mn2+ after charging to 3V. This explains the origin of the initial irreversible capacity loss partially. The quasi open circuit voltage and the relationship between the current density and the overpotential are investigated. Both indicate that there is a significant voltage difference between the charging and discharging profiles even when the current density decreases to zero.
A flexible, free-standing, thermostable gel polymer electrolyte based on plastic crystalline succinonitrile (SN) and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF4) entrapped in copolymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) is prepared and optimized for application in solvent-free solid-state supercapacitors. The synthesized gel polymer electrolyte exhibits a high ionic conductivity over a wide temperature range (from ∼5 × 10−4 S cm−1 at −30 °C up to ∼1.5 × 10−2 S cm−1 at 80 °C) with good electrochemical stability window (−2.9 to 2.5 V). Thermal studies confirm that the SN containing gel polymer electrolyte remains stable in the same gel phase over a wide temperature range from −30 to 90 °C. The electric double layer capacitors (EDLCs) have been fabricated using activated carbon as active materials and new gel polymer electrolytes. Electrochemical performance of the EDLCs is assessed through cyclic voltammetry, galvanostatic charge-discharge cycling and impedance spectroscopy. The EDLC cells with the proper SN-containing gel polymer electrolyte has been found to give high specific capacitance 176 F g−1 at 0.18 A g−1 and 138 F g−1 at 8 A g−1. These solid-state EDLC cells show good cycling stability and the capability to retain ∼80% of the initial capacitance after 10,000 cycles.
The path towards energy sustainability is commonly referred to the incremental adoption of available technologies, practices and policies that may help to decrease the environmental impact of energy sector, while providing an adequate standard of energy services. The evaluation of trade-offs among technologies, practices and policies for the mitigation of environmental problems related to energy resources depletion requires a deep knowledge of the local and global effects of the proposed solutions. While attempting to calculate such effects for a large complex system like a city, an advanced multidisciplinary approach is needed to overcome difficulties in modeling correctly real phenomena while maintaining computational transparency, reliability, interoperability and efficiency across different levels of analysis. Further, a methodology that rationally integrates different computational models and techniques is necessary to enable collaborative research in the field of optimization of energy efficiency strategies and integration of renewable energy systems in urban areas. For these reasons, a selection of currently available models for distributed generation planning and design is presented and analyzed in the perspective of gathering their capabilities in an optimization framework to support a paradigm shift in urban energy systems. This framework embodies the main concepts of a local energy management system and adopts a multicriteria perspective to determine optimal solutions for providing energy services through distributed generation.
In this work we report the investigation of the structural and the electrical properties of orthorhombic LiMnO2 in a wide temperature range in air and in high purity argon (N5). Also we present a correlation between the electrical and the electrochemical properties of the material upon lithium deintercalation. Moreover, its chemical stability against LiPF6 based liquid electrolyte at elevated temperatures was measured and compared with other cathode materials. High temperature investigations revealed occurrence of phase transitions. During heating in oxidizing and in inert atmosphere orthorhombic phase decomposes into LiMn2O4 and LiMn2O3. The conducted experiments also pointed to the instability of orthorhombic LiMnO2 during electrochemical lithium deintercalation. Both electrical conductivity and thermoelectric power of deintercalated samples altered substantially. DSC measurements proved high thermal stability of LiMnO2 based cathode material in contact with commercial liquid electrolyte.
Aiming at a more comprehensive understanding of the solid electrolyte interphase (SEI) in sodium ion batteries (NIBs), a detailed X-ray photoelectron spectroscopy (XPS) investigation of the few-nanometer thick passivation film formed on hard carbon (HC) in contact with various Na+-ion conducting electrolytes is reported. The electrolytes investigated include 1 M solutions of NaPF6, NaClO4, NaTFSI, NaFSI, and NaFTFSI, all dissolved in a common mixture of ethylene carbonate (EC) and diethylene carbonate (DEC) (EC/DEC = 1/1 wt. ratio). For comparison, the study of analogous Li-based electrolytes containing LiPF6 and LiFSI as representative electrolyte salts is also reported. The anion and cation of the electrolyte salt appear to play a key role in determining the overall SEI layer composition, including its depth evolution and thickness. The SEI building species formed on hard carbon by solvent reduction upon sodiation are found to decrease with the various salts in the order: NaPF6 > NaClO4 ≈ NaTFSI > NaFTFSI > NaFSI. The comparison of lithiated and sodiated HC electrodes shows that the SEI layer is more homogeneous and richer in organic species upon the use of Na-based electrolytes. Surface and depth-profiling XPS analysis on HC electrodes charged in the various electrolyte formulations provides in-depth insights on the differences and similarities of the SEI (composition, thickness, depth evolution, etc.) evolving from the variation in the chemical structure of the cations and anions of the respective salts.
New gel polymer electrolytes containing 1-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide (BMPyTFSI) ionic liquid are prepared by solution casting method. Thermal and electrochemical properties have been determined for these gel polymer electrolytes. The addition of BMPyTFSI to the P(EO)20LiTFSI electrolyte results in an increase of the ionic conductivity, and at high BMPyTFSI concentration (BMPy+/Li+ =1.0), the ionic conductivity reaches the value of 6.9×10−4 S/cm at 40°C. The lithium ion transference numbers obtained from polarization measurements at 40°C were found to decrease as the amount of BMPyTFSI increased. However, the lithium ionic conductivity increased with the content of BMPyTFSI. The electrochemical stability and interfacial stability for these gel polymer electrolytes were significantly improved due to the incorporation of BMPyTFSI.
Sm2O3-modified Li[Li0.2Mn0.56Ni0.16Co0.08]O2 was synthesized via a simple wet chemical process followed by a solid state reaction. A thin Sm2O3 layer with a thickness of about 2.5nm was uniformly coated on the surface of the Li-rich layered oxide particles. After Sm2O3 surface modification, high discharge capacity of 214.6mAhg−1 with a retention of 91.5% is obtained at a current density of 200mAg−1 between 2.0V and 4.8V after 80 cycles. Electrochemical impedance spectroscopy (EIS) shows that the thin Sm2O3 layer mainly reduces the charge transfer resistance and stabilizes the surface structure of the active material during cycling. Sm2O3 modification will be a promising approach to improve the cyclic stability of Li-rich layered oxides.
Cubic CuFe2O4 (c-CuFe2O4) and tetragonal CuFe2O4 (t-CuFe2O4) nanoparticles were selectively prepared using a facile one-step solid state reaction route by ferrous oxalate and copper acetate as the reactants. As an anode material for Li-ion batteries, compared with c-CuFe2O4 and t-CuFe2O4 synthesized at 800°C, c-CuFe2O4 synthesized at 400°C with smaller particle size and larger surface area exhibited superior discharge capacities and better cycling performance (950mAhg−1at 100mAg−1 after 60 cycles), and higher rate capability. The influence of the two crystal phases on the electrochemical performance were only exhibited at the Li+ insertion process during the first discharge. The average particle size and the surface areas play an important role in effecting the lithium-ion storage capability and cycling ability. Through ex situ HRTEM analysis, we observed the existence of metastable Fe x Cu1−x alloy in the discharged nanocomposition for the first time, which exhibits the interaction of metallic Cu particles with the adjacent iron ions.
The psychomotor challenges inherent in laparoscopic surgery are evident by the steep procedural “learning curves” documented throughout the literature. Few methods have been described to evaluate learning curves. The cumulative summation (CUSUM) method is a criterion-based evaluation of the learning process. The purpose of this study is to describe the CUSUM learning curves for a simple task for individuals and for a group of novice laparoscopists.
Environment enrichment (EE) has been demonstrated to improve the cognitive impairment that is induced by chronic cerebral hypoperfusion (CCH), but the underlying mechanism has not yet been elucidated. This study aimed to investigate the role of endogenous neuroprotection in EE-induced cognitive improvement in rats with CCH. Permanent bilateral common carotid artery occlusions (2-vessel occlusions (2VOs)) were performed to induce CCH in male adult Wistar rats. Four weeks after the surgeries, the rats were exposed to enriched environments for 4 weeks (6 h/day). Subsequently, we assessed the effects of EE on cognitive function, brain histone acetylation levels, neuroprotection-related transcription factors (i.e., cAMP response element-binding protein (CREB), phospho-CREB (p-CREB), hypoxia-inducible factor 1 (HIF-1) α, and nuclear regulatory factor 2 (Nrf2)), and oxidative stress and histological changes in the brain. After 2VO, the rats exposed to the EE treatment exhibited increased acetylation of histone 4 and increased p-CREB and Nrf2 protein levels in the brain. HIF-1α levels were increased after 2VO and reduced after EE treatment. The oxidative damage, histopathological changes in the brain, and spatial learning and memory impairments induced by 2VO were subsequently restored after EE treatment. These data indicate that EE promotes the acetylation of histone 4, regulates some neuroprotection-related transcription factors, attenuates oxidative damage, and protects against the histopathological damage to the brain induced by CCH. Together, the effects of EE in CCH rats might contribute to the recovery of spatial learning and memory.
Reversible thin film Fe(VI/III) cathodic charge/discharge storage in alkaline batteries is presented. Whereas ultra-thin (e.g., 3nm) Fe(VI/III) films exhibit a high degree of reversibility, thicker films are increasingly passive toward the Fe(VI) charge transfer. An extended conductive matrix facilitates a 100-fold enhancement in charge storage for reversible Fe(VI/III) super-iron thin films. The thicker (100s of nanometers) films deposited on extended conductive matrixes composed of high-surface-area Pt, Ti, and Au can sustain high reversibility, which provides the possibility of using Fe(VI) salts as the cathode materials for rechargeable Fe(VI)/metal hydride batteries. Super-iron cathodes can also be discharged in conjunction with a Li anode in nonaqueous media. Optimization of the nonaqueous primary super-iron/Li batteries is summarized. Fe(VI) cathodes are also reversible in nonaqueous electrolyte systems. The charge/discharge process of super-iron cathodes in nonaqueous media involves both the lithiation/delithiation of the active mass and the reduction/oxidation of the Fe(VI/III), while only the thin film Fe(VI/III) electrodes can sustain high reversibility involving the full theoretical capacity in the nonaqueous batteries.
Ultrafine powders of nanocrystalline CuFe2O4 and CuFe2O4/10wt.% SnO2 nanocomposites are prepared by a urea–nitrate combustion method. Phase pure and highly crystalline CuFe2O4 (tetragonal structure) and CuFe2O4/SnO2 (cubic structure) are obtained after sintering at 1100°C. The average particle size is 10–20 and 20–30nm, respectively. Both the nanoferrite anodes have an excellent specific capacity of greater than 800mAhg−1 versus Li metal. It is concluded that SnO2 doping improves the coulombic efficiency of copper ferrite anodes from 65 to 99.5% via an enhanced structural stability.
This paper proposed a novel centralized hardware fault detection approach for a structured Wireless Sensor Network (WSN) based on Naïve Bayes framework. For most WSNs, power supply is the main constraint of the network because most applications are in severe situation and the sensors are equipped with battery only. In other words, the battery’s life is the network’s life. To maximize the network’s life, the proposed method, Centralized Naïve Bayes Detector (CNBD) analyzes the end-to-end transmission time collected at the sink. Thus all the computation will not be performed in individual sensor node that poses no additional power burden to the battery of each sensor node. We have conducted thorough performance evaluation. The obtained results showed better performance can be obtained under a network size of 100-node WSN simulations at various network traffic conditions and different number of faulty nodes.
Energy is an essential ingredient of socio-economic development and economic growth. Many countries frequently held meetings and discussions has energy agenda. These countries are working to balance energy demand and supply. Renewable energy technology is one of the solutions, which produces energy by transforming natural phenomena into useful energy forms. Wind energy is a reliable and promising renewable energy. Wind energy becomes more and more attractive as one of the clean renewable energy resources. The installed capacity of electricity generation from wind energy is rapidly increasing in many countries and these countries are implementing variety incentive policies. Therefore, the importance of wind energy is expected to increase much more in the coming decades. The presented study comprehensively reviews wind energy in terms of three aspects, namely status, potential and policies analyses and assessments, for the first time to the best of the author's knowledge. This review paper covers the status, potential and policies of the wind energy, the issues faced, and the latest research. Also, the current situation, potential and development of the increasing are discussed. This study is presented recommendations for increasing the installed capacity of wind power.
Non-graphitizable carbon (NGC) has been obtained by carbonizing tubular polypyrrole (T-PPy) synthesized through a self-degraded template method. K-NGC/S composite has been prepared by mixing S with K-NGC via melt-diffusion method where NGC has been activated by potassium hydroxide (denoted as K-NGC) and is used as a conductive additive. The as-prepared K-NGC/S composite shows good specific discharge capacity and rate capability with an initial specific discharge capacity of 1121.9mAhg−1 and a specific discharge capacity of 729.7mAhg−1 after 50cycles at a current density of 335mAg−1, which is better than pure S. This improvement in the specific discharge capacity and the rate capability of the cell with K-NGC/S composite as a cathode material is realized by the existence of K-NGC, which can offers a superb conductive environment for S, effectively encapsulate S, restrain the outward diffusion of polysulfides, buffer volume change upon cycling and reduce the dissolution of lithium polysulfides into the electrolyte. The good electrochemical performance of K-NGC/S composite would make it become a promising cathode material for lithium-sulfur batteries.
Deeply fluorinated multi-wall carbon nanotubes (F-MWCNTs) with different diameters are prepared using the mixture of fluorine/nitrogen gas, and the molar ratio of fluorine to carbon is controlled to be approximate to 1. The electrochemical performances of F-MWCNTs are tested as the cathode material in primary lithium battery. The discharge rate of 4C can be applied for these F-MWCNTs and F-MWCNTs with average diameter larger than 50nm can support the high discharge rate up to 5C delivering a maximum power density of 7114.1Wkg−1, associated with a high 1923Whkg−1 energy density. The conductive networks of intimately contacting MWCNTs in nano-scale and the intrinsic fast rate capability of one-dimensional nanostructures account for the high power density of F-MWCNTs. Moreover, F-MWCNTs with larger diameter exhibits better electrochemical performances. Based on the pore size distribution and impedance results, it is proposed that the F-MWCNTs with larger diameters can effectively avoid the surface and networks of F-MWCNTs being blocked by the enlarged LiF crystals, and hence display the better electrochemical performances.
The electrodeposition of zinc films from zinc triflate (Zn(TfO)2) in two air and water stable ionic liquids namely, 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO, and 1-ethyl-3-methylimidazolium trifluoromethylsulfonate, [EMIm]TfO, was studied. The influence of water on the deposition process was also investigated. The morphology of the obtained deposit is different in the two liquids. Dense and uniform silvery zinc deposits with good adherence were obtained from [EMIm]TfO while less adhering and dark gray zinc deposits were obtained from [Py1,4]TfO. The SEM results of the deposit obtained from [EMIm]TfO revealed a hexagonal zinc structure while a flower-like structure was observed for the deposits obtained from [Py1,4]TfO under the same conditions. Water added to the electrolyte has a distinct effect on the deposits obtained in [EMIm]TfO and [Py1,4]TfO, respectively. The difference in the structure might be attributed to the different interaction of the ions with the substrate. Furthermore, the addition of water to the solution decreases the electrochemical window of both ionic liquids and shifts the reduction of zinc(II) to less negative values. The XRD phase analysis showed that not only Zn was deposited in the dried ionic liquids also Zn-Au alloys were obtained. However, in ionic liquid/water mixtures only Zn was obtained, surprisingly. Furthermore, Zn deposits obtained at 50°C showed a preferential orientation compared with those ones obtained at room temperature. Both the water concentration and the temperature affect the deposition process.
Uniformly dispersed carbon coated Sn-MnO nanocomposite (Sn-MnO@C) has been fabricated by thermal annealing of MnSn(OH)6 nanoparticles precursor in acetylene/argon gas (1/9; v/v). Benefiting from this unique method, the synchronously formed Sn and MnO nanocrystals both with size about 12nm were uniformly dispersed in the amorphous carbon matrix. Meanwhile, a porous structure appeared which could be attributed to the dehydration of MnSn(OH)6 in the calcination process. As the anode for lithium-ion batteries, the Sn-MnO@C nanocomposite demonstrates a reversible capacity of 684mA h g−1 after 280 cycles at a current of 100mAg−1. The fine electrochemical performance mainly attributes to uniformly dispersed nanoparticles, porous structure as well as amorphous carbon matrix coating.
All properties of mobile wireless sensor networks (MWSNs) are inherited from static wireless sensor networks (WSNs) and meanwhile have their own uniqueness and node mobility. Sensor nodes in these networks monitor different regions of an area of interest and collectively present a global overview of monitored activities. Since failure of a sensor node leads to loss of connectivity, it may cause a partitioning of the network. Adding mobility to WSNs can significantly increase the capability of the WSN by making it resilient to failures, reactive to events, and able to support disparate missions with a common set of sensor nodes. In this paper, we propose a new algorithm based on the divide-and-conquer approach, in which the whole region is divided into sub-regions and in each sub-region the minimum connected sensor cover set is selected through energy-aware selection method. Also, we propose a new technique for mobility assisted minimum connected sensor cover considering the network energy. We provide performance metrics to analyze the performance of our approach and the simulation results clearly indicate the benefits of our new approach in terms of energy consumption, communication complexity, and number of active nodes over existing algorithms.
Lithium-ion batteries are used as the main power source in many electronic and electrical devices. In particular, with the growth in battery-powered electric vehicle development, the lithium-ion battery plays a critical role in the reliability of vehicle systems. In order to provide timely maintenance and replacement of battery systems, it is necessary to develop a reliable and accurate battery health diagnostic that takes a prognostic approach. Therefore, this paper focuses on two main methods to determine a battery's health: (1) Battery State-of-Health (SOH) monitoring and (2) Remaining Useful Life (RUL) prediction. Both of these are calculated by using a filter algorithm known as the Support Vector Regression-Particle Filter (SVR-PF). Models for battery SOH monitoring based on SVR-PF are developed with novel capacity degradation parameters introduced to determine battery health in real time. Moreover, the RUL prediction model is proposed, which is able to provide the RUL value and update the RUL probability distribution to the End-of-Life cycle. Results for both methods are presented, showing that the proposed SOH monitoring and RUL prediction methods have good performance and that the SVR-PF has better monitoring and prediction capability than the standard particle filter (PF).
The commercial use of lithium metal batteries was delayed because of dendrite formation on the surface of the lithium electrode, and the difficulty finding a suitable electrolyte that has both the mechanical strength and ionic conductivity required for solid electrolytes. Recently, strategies have developed to overcome these difficulties, so that these batteries are currently an option for different applications, including electric cars. In this work, we review these strategies, and discuss the different routes that are promising for progress in the near future.
HIV-1 infection remains a major public health concern despite effective combination antiretroviral therapy (cART). The virus enters the central nervous system (CNS) early in infection and continues to cause HIV-associated neurocognitive disorders (HAND). The pathogenic mechanisms of HIV-associated brain injury remain incompletely understood. Since HIV-1 activates the type I interferon system, which signals via interferon-α receptor (IFNAR) 1 and 2, this study investigated the potential role of IFNAR1 in HIV-induced neurotoxicity.