batterydata/paper-abstracts huggingface dataset:
A series of nano-sized tin-doped metal oxides of titanium(IV), niobium(V) and vanadium(IV), were directly synthesized using a continuous hydrothermal process and used for further testing without any post-treatments. Each of the as-prepared powders was characterized via a range of analytical techniques including powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and Brunauer-Emmett-Teller surface area measurements, as well as being investigated as an electrode material in a lithium-ion coin cell (vs lithium metal). All the tin-doped nanomaterials showed higher specific capacities compared to their undoped metal oxide counterparts. The increased charge storage was discussed to originate from the electrochemical activation of the tin dopant as an alloying material. Overall, this work presents a reliable method of combining stable insertion materials with high capacity tin alloying materials under scaled-up conditions.
Nanostructured silicon is a promising candidate material for practical use in energy storage devices. However, high temperature operation remains a significant challenge because of severe electrochemical side reactions. Here, we show the design of ultra-durable silicon made by introducing dual coating layers on the silicon surface, allowing stable operation at high temperature. The double layers, which consist of amorphous metal titanate and carbon, provide several advantages including: (i) suppression of volume expansion during Li+ insertion; (ii) creation of a stable solid-electrolyte−interface layer; and (iii) preservation of original Si morphology over 600 cycles at high temperature. The resulting silicon-based anode exhibits a reversible capacity of 990mAhg−1 after 500 cycles at 25°C and 1300mAhg−1 after 600 cycles at 60°C with a rate of 1C.
Carbon-coated spinel Li4Ti5O12 anode material was prepared by heat-treating the mixture of TiO2 (anatase), Li2CO3 and sugar. The products were characterized by X-ray diffraction, scanning electronic microscope and transmission electron microscope. A nanolayer of amorphous carbon was homogeneously coated on the surface of Li4Ti5O12 particles. Electrochemical results show that the carbon-coated Li4Ti5O12 displays larger diffusion coefficient of lithum ions, higher rate capability and excellent reversibility. Its reversible capacity is approximately 160mAhg−1 at the rate 0.1C and good cycling behavior at different current density is achieved.
Energy storage systems (ESS) have a wide spectrum of functions. They must provide power quality, shaving of load change, coordination of distributed power systems, bulk energy storage, and end-user reliability, e.g., uninterrupted power supply. In present paper the configuration and design of experimental ESS based on both Li-ion batteries and supercapacitors have been proposed. Such a hybrid energy storage system (HESS) includes three main components: Li-ion batteries, supercapacitors, and grid interconnection consisting of two invertors and control and monitoring system. Energy storage capacity of developed HESS prototype is 100 kWh, nominal power—100 kW, peak power—200 kW. HESS was created and tested within the experimental facility also including 1.5 MW gas turbine power plant, 200 kW controllable active and reactive loads, and control and measurement system. Experimental results showed that HESS successfully provides the following advantages: (i) suppression of voltage, current, and frequency disturbances in the grid; (ii) compensation of reactive power in the circuit; and (iii) uninterrupted power supply. Cost analysis of proposed hybrid system has also been carried out. In comparison with battery ESS without supercapacitors, HESS showed longer life time, lower cost, and higher peak power.
Poverty reduction strategy papers represent both a primary policy device of international development institutions, and an instance of a wider international convergence of public policy around global integration and social inclusion. Charting the emergence of these approaches, this paper argues that this convergence has a number of structural predilections which favor the technical and juridical over the political economic, and a disciplinary framework over a practical contest. Drawing extensively on decentralized governance and poverty reduction programs in Uganda, this paper shows how these predilections obscure power relations and restrict practical and political options, while exacting heavy establishment and compliance costs.
Defence R&D Canada (DRDC) is investigating lithium-ion polymer cells for possible future use in army communications and soldier systems, because of their high specific energy. Military operation requires good performance at −20°C but the standard commercial lithium-ion polymer cells yield only approximately 30% of their room temperature capacity at this temperature. The standard electrolyte is known to be poorly conducting at −20°C, so DRDC has been working with a Canadian company to produce a cell containing an electrolyte that gives good low temperature performance. Prototype cells have been built and cycled under various conditions. The performance of these cells and the standard cells is discussed.
A sustainable solid-state strategy of SPEX milling is developed to coat metal oxide (e.g., Fe3O4) with tunable layers of graphene, and a new hierarchical core-shell structured Fe3O4@graphene composite is constructed. The presented green process can preserve the physicochemical properties of metal (oxide) nanocrystals well while conveniently modifying them with graphene carbon, which is unique from the conventional approaches carried out in the solution followed by high temperature calcinations/carbonization. This strategy is environmental-friendly, cost-effective and feasible to extend for preparing more metal (oxide)-graphene materials readily with controllable layers of graphene. In energy storage applications, as-prepared Fe3O4@graphene only modified with 10 wt% of graphene can show greater capacity of 283 mAh g−1 at 100 mA g−1 with capacity retention of 84% over 100 cycles in sodium battery (vs. 17% of pristine Fe3O4). As an appealing nonflammable anode, a completely new full battery of Fe3O4@graphite/Na2.4Fe1.8(SO4)3 is assembled, and an impressive energy density beyond 300 Wh kgcathode −1 with a high working voltage of 3.2 V is attained. Such kind of green battery comprising from the earth-abundant elements (i.e., Na, Fe, S and O) can demonstrate extremely long cycle ability over 500 cycles and robust rate capability even to 10 C (where 1 C define as 108 mA gcathode −1) which are rarely reported before.
Aqueous zinc-ion batteries (ZIBs) have been considered as one of the most promising electrochemical devices for large-scale energy storage system owing to their low cost and high safety. Herein, Na2V6O16·2.14H2O nanobelts are synthesized and applied as cathode material for ZIBs. The sample displays a high capacity of 466 mAh g−1 at 100 mA g−1 and stable cycling performance with a capacity retention of 90% over 2000 cycles at the 20 A g−1. Moreover, Na2V6O16·2.14H2O presents a capable rate ability and a high energy density of 312 Wh kg−1 at a specific power of 70 W kg−1. The superior electrochemical performance is attributed to the large interlayer spacing and outstanding structure stability, which promise the highly reversible intercalation and extraction of zinc ion. The electrochemical kinetics and zinc ion storage mechanism are also investigated. This work demonstrates that nanoscale electrode materials with large interlayer spacing can effectively enhance the electrochemical performance of aqueous ZIBs, which can be extended to other metal ion batteries, such as magnesium ion batteries and aluminum ion batteries.
Porous Si/C/reduced graphene oxide (Si/C/rGO) microspheres have been prepared by the spray drying and subsequent carbonization process using the polyvinyl alcohol (PVA) as cross-linking agent. PVA plays an important role in the spray drying process. The designed micrometer-size reduced graphene oxide wrapped Si/C ball structure offers a buffer space for the volume change of Si during the charge-discharge process. Double carbon layers can effectively protect the Si core and improve the cycling stability of the electrode. The fabricated Si/C/rGO microspheres as anode for lithium ion batteries exhibit a high reversible capacity of 928mAhg−1 after 70cycles at a current density of 100mAg−1, good rate capability and cycling stability.
In recent times, synthesis, development and fabrication of anode component of solid oxide fuel cell (SOFC) have gained a significant importance, especially after the advent of anode supported SOFC. The function of the anode electrode involves the facilitation of fuel gas diffusion, oxidation of the fuel, transport of electrons and transport of by-product of the electrochemical reaction. Although impressive progress has been made in the development of alternative anode materials with mixed conducting properties and few of the other composite cermets, Ni/YSZ continues to be the most sought after anode for high temperature SOFC applications. Despite of its poor carburization and sulfidation capabilities during the operation of SOFC directly on hydrocarbons, Ni/YSZ continues to be the most opted anode electrode material due to its high catalytic activity for hydrogen oxidation, methane reforming, high electronic and ionic conductivity and stability. Present review focuses on the various aspects pertaining to Ni/YSZ as an anode in SOFC. Various factors that influence the ohmic, activation and the concentration polarization contribution of anode while using Ni/YSZ are discussed. Importance of optimizing the composition, microstructure and porosity to minimize the above mentioned polarizations are discussed extensively. Various synthesis methods that are used in the preparation of optimized NiO/YSZ composite powder and the methods that are adopted to fabricate anode component are provided in detail in the article. Information on Ni/YSZ anode failure and strategies to improve the long term stability are also discussed exhaustively. Parameters that influence the carburization and sulfidation of Ni/YSZ while using hydrocarbons as fuel are elaborated in this article and means to minimize the same are also discussed.
The decreased participation in physical activity by children with probable developmental coordination disorder (pDCD) has raised concerns about their aerobic fitness and lung function levels. The purpose of the present study was to examine assessment of cardiorespiratory and neuromotor fitness, using laboratory-based tests during an incremental treadmill protocol in healthy children with and without pDCD. Twenty sex children ages 6–9 years took part in this study. Motor coordination was assessed using the Movement Assessment Battery for Children (MABC). All participants performed a cardiopulmonary exercise test (CPET) on a cycle ergometer. Pulmonary function was assessed by spirometric measurements (forced vital capacity: FVC, forced expiratory volume in 1s: FEV1) and walking distance (6MWD) was assessed using the 6-min walking test. The children with pDCD had lower VO2max than children without pDCD (p <0.01). Moreover, FVC and FEV1 were significantly higher in children without pDCD than in children with the disorder (p <0.05, p <0.01 respectively). Likewise, children with pDCD had poorer performance on the 6MWD than children without pDCD (p <0.01). A significant correlation between the absolute value for FEV1 and 6MWD (r =0.637, p <0.05) in pDCD group was observed. We found a significant correlation between VO2max and MABC score (r =−0.612, p <.001) and between VO2max and 6MWD (r =0.502, p <.001) for all children. Moreover, a significant correlation between VO2max and FEV1 (r =0.668, p <.05) was found in children with pDCD. Overall, the reduced aerobic capacity of DCD was associated with decreased of lung function, as well as an alteration of peripheral muscle responses.
Nitrogen-containing microporous carbon nanotubes were prepared via the carbonization of polyaniline/silica nanotube composites in order to obtain a new type of carbon electrode material. As a carbon precursor, polyaniline was coated onto a silica nanotube and subsequent carbonization was performed at 850°C. After carbonization and silica etching, the nitrogen-doped carbon nanotubes (N-CNTs) show a 1D hollow structure with a high specific surface area; then, the N-CNTs are chemically activated using a KOH solution. It was found that the specific surface area of the activated N-CNTs (AC-N-CNTs) significantly increased to 1958m2/g with chemical activation compared with N-CNTs (217m2/g). In addition, the specific capacitance (254.6F/g) of the AC-N-CNTs was higher than that of the N-CNTs (218.6F/g). This superior performance is attributed to the synergistic effect between the high specific surface area and nitrogen group of the AC-N-CNTs, indicating the combination effect of both the electric double layer capacitance and pseudocapacitive reaction.
Electrochemical properties and working mechanisms of benzyl isocyanate compounds as polymerizable electrolyte additives for overcharge protection of lithium ion batteries have been studied by cyclic voltammetry, charge–discharge cycling, overcharge tests, accelerating rate calorimetry (ARC) and in situ Fourier transform infrared spectroscopy (FTIRS). The overcharge and FTIRS data clearly reveal that 4-bromobenzyl isocyanate (Br-BIC) can electrochemically polymerize at 5.5V (versus Li/Li+) to form an overcharge-inhibiting (probably insulating) film on the cathode surface. In addition, is found the Br-BIC does slightly improve the charge/discharge performance of a lithium ion battery. Furthermore, Br-BIC and benzyl isocyanate show beneficial solid electrolyte interphase (SEI) formation behaviour on graphite in propylene carbonate based electrolyte solutions.
The versatility of anaerobic digestion (AD) as an effective technology for solving central challenges met in applied biotechnological industry and society has been documented in numerous publications over the past many decades. Reduction of sludge volume generated from wastewater treatment processes, sanitation of industrial organic waste, and benefits from degassing of manure are a few of the most important applications. Especially, renewable energy production, integrated biorefining concepts, and advanced waste handling are delineated as the major market players for AD that likely will expand rapidly in the near future. The complex, biologically mediated AD events are far from being understood in detail however. Despite decade-long serious academic and industrial research efforts, only a few general rules have been formulated with respect to assessing the state of the process from chemical measurements. Conservative reactor designs have dampened the motivation for employing new technologies, which also constitutes one of the main barriers for successful upgrade of the AD sector with modern process monitoring instrumentation. Recent advances in Process Analytical Technologies (PAT) allow complex bioconversion processes to be monitored and deciphered using e.g. spectroscopic and electrochemical measurement principles. In combination with chemometric multivariate data analysis these emerging process monitoring modalities carry the potential to bring AD process monitoring and control to a new level of reliability and effectiveness. It is shown, how proper involvement of process sampling understanding, Theory of Sampling (TOS), constitutes a critical success factor. We survey the more recent trends within the field of AD monitoring and the powerful PAT/TOS/chemometrics application potential is highlighted. The Danish co-digestion concept, which integrates utilisation of agricultural manure, biomass and industrial organic waste, is used as a case study. We present a first foray for the next research and development perspectives and directions for the AD bioconversion sector.
Strong demand for higher energy batteries for extended range electric vehicles has driven battery technology development toward Li metal batteries. One limitation of Li metal batteries is cycle life. At odds are the amount of electrolyte to fulfill high energy and the amount needed to achieve long cycle life. Here we employ an electrochemical model and design of experiment to understand impacts on cycle life and failure as electrolyte content is reduced to levels needed to achieve reasonably high specific energy. With lean electrolyte, a gap exists in achieving long cycle life with a reduction by a factor of 6.5 when electrolyte amount is reduced from 37.0 g Ah−1 to 6.0 g Ah−1. Two primary failure routes are identified with differences between lean and high electrolyte quantities. The results suggest that reporting and performing experiments for high energy cell designs requires that amount of electrolyte be considered a critical parameter.
With their high catalytic activity, stability, selectivity, and 100% atom utilization, single atomic non-noble metal based materials are valuable alternatives to efficient but expensive Pt based catalysts. For efficient catalysis, single-atom catalysts must expose abundant single atomic metal active centers. Here, we report the rational design and synthesis of a Cu single-atom catalyst with high Cu content of over 20.9 wt%, made of single atomic Cu anchored into an ultrathin nitrogenated two-dimensional carbon matrix (Cu–N–C). The high Cu content was achieved by the introduction of additional N species, which can securely trap and protect the Cu atoms. During oxygen reduction, the single atomic Cu exhibited over 54 times higher mass activity than metallic Cu nanoparticles at a potential of 0.85 V versus a reversible hydrogen electrode (RHE). Furthermore, the Cu–N–C exhibited 3.2 times higher kinetic current at 0.85 V (vs. RHE), and a much lower Tafel slope (37 mV dec−1), as well as better methanol/carbon monoxide tolerance and long-term stability than commercial Pt/C. Density functional theory (DFT) calculations reveal that the Cu active sites exhibit improved O–O bond stretching and favorable adsorption energies of O2 and OOH for four-electron oxygen reduction.
Abstract This chapter presents a clear survey of graphene preparation methods. The three main routes of mechanical exfoliation, oxidation-reduction, and intercalation-exfoliation are used in the top-down method. Although the mechanical exfoliation method is easier, graphene nanolayers prepared from the intercalation-exfoliation method provide high purity and yield. Against the high hydrophobicity of graphene, graphene oxide produced from oxidation-reduction methods possesses hydrophilic functional oxidized groups. Although pyrolysis and vapor deposition are reported for the bottom-up method, less progress has been reported. The application of graphene as a component material of supercapacitors, a type of energy storage device, attracts great attention. Graphene provides high power density and stability in electric double layer capacitors, but hybridization with pseudecapacitor materials is required for supplying efficient energy density.
The structural integrity of the separator is crucial to the abuse tolerance of a battery. To estimate its stress level in a battery, the mechanical property of the separator in situ in the battery environment must be known. This work investigated the tensile behavior of a single layer polypropylene (PP) separator in electrolyte solutions for Li-ion batteries using a dynamic mechanical analyzer (DMA). The measurements were carried out in both dry (ambient) and wet conditions for both the machine direction (MD) and the transverse direction (TD). In the wet condition, samples were submerged either in a DMC solvent or in a electrolyte solution of 1.1M LiPF6 in EC/DMC (1/1 by volume). The DMA experiments were performed under uniaxial tension, creep, and frequency sweep modes. The results in all three modes demonstrated that the mechanical properties of the separator were significantly lower in wet conditions. For instance, in the MD, relative to the dry condition, the ratio of the Young's modulus was about 0.49 and 0.52 for DMC and 1.1M LiPF6 in EC/DMC, respectively. The results indicate that the mechanical properties measured in dry condition using samples that had been preconditioned in solutions are not sufficient to represent the in situ material behavior.
A datacenter, which is a highly distributed multiprocessing system, needs to keep accurate track of time across a large number of machines. Precise time synchronization has become a critical component due to stringent requirements of several time critical applications such as real-time big data analytics, high-performance computing, and financial trading. Our study starts with a survey on the most relevant time synchronization techniques for datacenter networks. Then, we propose a zero-overhead microsecond-accuracy solution to synchronize a packet-switched optical network for datacenters. To achieve the desired time accuracy, we consider precision time protocol to synchronize the server clocks with a central controller clock. Zero-overhead is maintained by using data traffic to carry the time messages instead of a separate control channel. Through simulation, we show that microsecond level of time accuracy can be achieved. We also discuss the dependency of the accuracy on different traffic loads, traffic distributions, and packet lengths.
Summary The authors wished to obtain a ‘snapshot’ of the range of practice in the management of split skin graft donor sites in the British Isles. Material/Methods Questionnaires were sent to all British consultants and locum consultant plastic surgeons on 1 July 2006. Of the 357 questionnaires, 279 were returned (a response rate of 78%). Results Alginates were the most popular dressings, especially in adult donor sites – first choice for 167 respondents (60%). Adhesive fabrics were less popular – first choice for small adult donor areas for 46 respondents (16%). Plastic film dressings and Biobrane were even less popular – being the first choice for small and large donor areas, respectively, in children (for approximately 5% of respondents). Ten percent of respondents said they avoid paraffin gauze and another 10% avoid plastic film dressings in all cases. Five percent avoid hydrocolloid and another 5% avoid adhesive fabric in all cases. Conclusion On the basis of these results, we feel that any future study of donor-site dressings should incorporate the most commonly used dressing (alginate) as a control.
A novel spinel cathode material with an average composition of LiMn1.912Ni0.072Co0.016O4, in which the LiMn2O4 core material is completely encapsulated by a stable spinel structure concentration-gradient shell (CGS), is successfully synthesized via co-precipitation process. The spherical LiMn2O4 core is encapsulated by CGS that increased continuously Ni and Co contents, and the composition of the outmost layer of the spherical LiMn1.912Ni0.072Co0.016O4 is LiNi0.45Mn1.45Co0.1O4. The electrochemical properties of the LiMn1.912Ni0.072Co0.016O4 compared to the LiMn2O4 are carefully investigated by galvanostatic charge–discharge, cyclic voltammetric and electrochemical impedance spectroscopy. It has been found that the electrochemical properties of the LiMn1.912Ni0.072Co0.016O4 material are far superior to those of the alone LiMn2O4 core material. Besides, the LiMn1.912Ni0.072Co0.016O4 sample exhibits excellent cycling stability at elevated temperature. It delivers a discharge capacity of 118 mAh g−1 between 3.0 and 4.4 V vs. Li/Li+ with a retention of 96% over 200 cycles at a rate of 1 C (148 mA g−1) at 55 °C. In the same time, the LiMn1.912Ni0.072Co0.016O4 shows also a good rate capability. It can still deliver a high discharge capacity of over 110 mAh g−1 even at a rate of 5 C. Therefore, the core–shell structure spinel cathode material with CGS will be a promising cathode material for advanced lithium ion batteries.