batterydata/paper-abstracts huggingface dataset:
In the present paper, the hierarchical three-dimensional Fe3O4@porous carbon matrix (PCM) and Fe3O4@PCM/graphene are synthesized by a facile annealing of Mil-53(Fe) templates. Their electrochemical performances are evaluated as anode materials for lithium ion batteries. In comparison with Fe3O4@PCM, the Fe3O4@PCM/graphene electrode exhibits a much better cycling performance with the reversible capacity high up to 1000 mAh g−1 after 500 cycles at 1 C. The improved performance can be ascribed to the high conductivity and structure stability provided by the unique graphene based hierarchical three-dimensional nanostructure.
Whereas a vast amount of research has demonstrated the association between core self-evaluations (CSE) and well-being indicators, few studies have specifically focused on the ways in which CSE might facilitate an increased well-being. This study assesses whether perceived stress might either be a potential mediator and/or moderator in the relationship between CSE and life satisfaction in two independent samples: middle-aged adults (N = 320) and young adults (N = 473). In both samples, participants completed a battery of questionnaires composed of a CSE scale, perceived stress scale and life satisfaction scale. Bootstrap analyses showed that perceived stress partially mediated the relationship between CSE and life satisfaction in both samples. However, moderation analyses failed to support that perceived stress moderated the influence of CSE on life satisfaction either in middle-aged adults or young adults samples. The implications of these findings for research and practice are discussed.
Co3O4 has been investigated intensively for its high specific capacity which makes it a promising candidate anode for high-performance lithium ion batteries (LIBs). However, rational design of Co3O4 electrode that is beneficial for its electrochemical performance is still a great challenge. Herein, we designed and fabricated porous Co3O4 nanotubes (P-Co3O4-NTs) by coaxial electrospinning method followed by a fine annealing treatment, which display one dimensional tubular structure with porous wall and hollow interior. The uniqueness of this strategy is that the morphologies of the P-Co3O4-NTs could be tuned by adjusting the mass ratio of reactants. The resultant P-Co3O4-NTs exhibit excellent lithium storage performance in terms of specific capacity, rate capability, and cycling stability, when used as an anode material for rechargeable LIBs. This unique structure endows a high reversible specific capacity of 1826.2mAg−1 at a current density of 0.3Ag−1 after 100 cycles. Even at high current densities of 2 and 5Ag−1, the P-Co3O4-NTs electrode still could deliver remarkable discharge capacities of 1506.2 and 1145.1mAhg−1, respectively. The excellent electrochemical performance can be attributed to the unique tubular and porous structure of P-Co3O4-NTs, which not only can accommodate the large volume change but also can provide an excellent ion diffusion and electronic conduction pathway. Therefore, the P-Co3O4-NTs have the potential for use as a high performance anode material in LIBs.
Rather than depend on highly acidic or basic electrolytes, ionic liquids are used to create new types of solid state cells which mimic standard alkaline cells, but without the need for caustic electrolytes. Presented here is a non-aqueous approach to primary and secondary power sources, where the pure ionic liquid not only acts as the electrolyte/separator in both liquid and solid state batteries, but as a reactive species in the cell's electrochemical makeup. In this work, batteries are designed using standard cathode and anode materials such as MnO2/Carbon, PbO2, NiO, AgO and Zn. However, by using a solid polymer electrolyte composed of an ionic liquid and polyvinyl alcohol, novel types of solid state batteries are demonstrated with discharge voltages ranging up to 1.8V, dependent upon the type of cathode and anode used. These batteries are characterized by ionic conductivity, initial voltage measurements, and discharge profiles.
Lithium-ion capacitors (LICs) were investigated for high power, moderate energy density applications for operation in extreme environments with prolonged cycle-life performance. The LICs were assembled as three-layered pouch cells in an asymmetric configuration employing Faradaic pre-lithiated hard carbon anodes and non-Faradaic ion adsorption-desorption activated carbon (AC) cathodes. The capacity retention was measured under high stress conditions, while the design factor explored was electrolyte formulation using a set of carbonates and electrolyte additives, with a focus on their stability. The LIC cells were evaluated using critical performance tests under the following high stress conditions: long-term voltage floating-cycling stability at room temperature (2.2–3.8 V), high temperature storage at 3.8 V, and charge voltages up to 4.4 V. The rate performance of different electrolytes and additives was measured after the initial LIC cell formation for a 1C–10C rate. The presence of vinylene carbonate (VC) and tris (trimethylsilyl) phosphate (TMSP) were found to be essential to the improved electrochemical performance of the LIC cells under all testing conditions.
Electrochemically deposited poly(N-methylaniline) (PNMA) is evaluated as a cathode active material together with a Zn anode in the fabrication of rechargeable cells in 1M ZnSO4 electrolyte at pH ∼5. The cell shows an open-circuit voltage (OCV) of 1.35V and a specific capacity of 25.8Ahkg−1. In a second set of experiments, the anion-exchanging PNMA is converted to a cation-exchanging electrode by sulfonation and evaluated in cells. Such an approach enhances the specific capacity of the cell by a factor of 4. The coulombic efficiency of the cell is also increased considerably. A few related experiments are performed on the parent polymer, polyaniline, to facilitate direct comparison of the results.
Over the past decades, two-dimensional (2D) nanomaterials possessing planar layered architecture and unique electronic structures have been being quickly developed, due to their wide potential application in the fields of chemistry, physics, and materials science. As a new family of 2D nanomaterials, 2D polymer-based nanosheets, featuring excellent characters, such as tunable framework structures, light weight, flexibility, high specific surface, and good semiconducting properties, have been emerging as one kind of promising functional materials for optoelectronics, gas separation, catalysis and sensing, etc. In this review, the recent progress in synthetic approach and characterization of 2D polymer-based nanosheets were summarized, and their current advances in electrochemical energy storage and conversion including second batteries, supercapacitors, oxygen reduction and hydrogen evolution were discussed systematically.
In this study, flake-like sheets (S-MVO) and flowers-like MnV2O6 (F-MVO) anode materials are synthesized by a facile hydrothermal technique for the first time applied to Na-ion storage. In order to better understand the behavior of Na atoms in the structure of MnV2O6, ab-initio methods predict for convenient migration paths. Additionally, first-principle calculations are used to determine the electronic and optical properties. The steady reversible discharge capacity exhibits 348 mAh g−1 for S-MVO electrode and 231 mAh g−1 for F-MVO electrode at a current density of 100 mA/g over the 50 cycles. The stable reversible capacity ascribed from conversion with combination of intercalation/deintercalation reaction. The S-MVO sample demonstrates significant electrochemical performance without any hybridizing of carbonaceous materials. The mesoporous thin morphology provides enhanced kinetics activity, which suggests facilitating the electronic/ionic transfer. Thus, the simple manner of Na+ migration path prediction, cost-effective route of bi-metal mixed novel materials may open a way for the design of potential electrodes for commercial and future large-scale high-performance Na-ion energy storage devices.
Faced with the challenge of distributing digital product in the digital realm, the American film industry is acutely aware of its increasing vulnerability to piracy and is currently considering two solutions to protect its copyrights—a legislative solution (e.g., the Digital Millennium Copyright Act of 1998) and a technical solution (e.g., digital watermarking). We suggest that a better way of dealing with piracy is an economic solution, such as neutralizing piracy by reengineering the supply chain across all three sectors of the motion picture industry: distribution, exhibition, production. In distribution, the industry can make legitimate downloading of high-quality movie files easier and cheaper (than pirating) by strategically locating “e-Blockbusters” (i.e., digital movie libraries) at or near Internet service provider (ISP) sites and making them attractive through feasible pricing schemes. In exhibition, innovative digital theaters could offer virtual reality viewing experiences and flexible windowing systems that maximize revenue for each feature film. In production, work would be done primarily or entirely in the digital domain. Digital film reservoirs would provide universal naming and indexing functions for easy access, reuse, and extension, and the industry would achieve a new diversity of quality and quantity. In addition, dynamic cross-media convergence can be expected as a function of the complementarities created by content digitization. To prosper in the new digital economy, the motion picture industry must closely collaborate with the information industry to achieve a new supply chain rather than competing with it to the detriment of both.
The standard enthalpy of formation of perspective solid electrolyte Li7La3Zr2O12 is determined using thermodynamic cycles based on the measurement of its enthalpy of dissolution. The standard molar enthalpies of dissolution in aqueous solution of 1moldm−3 HCl, formation from binary oxides and formation from elements for tetragonal form of Li7La3Zr2O12 are found to be −1547.6, −168.0 and −7152.6kJmol−1, respectively.
To establish a reliable, reproducible and accurate release of the drug in the gastrointestinal tract, a novel release mechanism for a controllable drug-delivery system has been investigated. The release mechanism, consisting of a one-way valve for drug release, a drug chamber, two axially magnetized cylindrical permanent magnets and a multi-layer solenoid coil, is hosted in the capsule-shaped shell with diameter 11 mm and length 30 mm. To actuate the coil piston, the two static magnetic fields produced by the two magnets are aligned along the same axis, having the same magnitude, but opposite directions. Based on the principle of the electromagnetic force and the Bernoulli equation, the actuating force can be expressed as a function of the coil stroke and the excitation current, which was modeled and experimentally verified. Thus the actuating force can be controlled by adjusting the activated period and intensity of the coil, resulting in the reproducible release with different doses and mean rates. Then, a prototype of the drug-delivery system has been developed, which consists of a drug-delivery capsule, a radio frequency transmission module, an interface circuit, and an instruction setting and triggering platform. All the drug release parameters, including the release mode, times, dose and mean flow rate, can be set by the platform. The experiment verifies that the drug-delivery capsule can deliver a predetermined dose with different flow rates and dip angles of the capsule. The relative error of the releasing dose becomes larger with increasing releasing rate and decreasing releasing dose.
Hospital waste management is an imperative environmental and public safety issue, due to the waste’s infectious and hazardous character. This paper examines the existing waste strategy of a typical hospital in Greece with a bed capacity of 400–600. The segregation, collection, packaging, storage, transportation and disposal of waste were monitored and the observed problematic areas documented. The concentrations of BOD, COD and heavy metals were measured in the wastewater the hospital generated. The wastewater’s toxicity was also investigated. During the study, omissions and negligence were observed at every stage of the waste management system, particularly with regard to the treatment of infectious waste. Inappropriate collection and transportation procedures for infectious waste, which jeopardized the safety of staff and patients, were recorded. However, inappropriate segregation practices were the dominant problem, which led to increased quantities of generated infectious waste and hence higher costs for their disposal. Infectious waste production was estimated using two different methods: one by weighing the incinerated waste (880kgday−1) and the other by estimating the number of waste bags produced each day (650kgday−1). Furthermore, measurements of the EC50 parameter in wastewater samples revealed an increased toxicity in all samples. In addition, hazardous organic compounds were detected in wastewater samples using a gas chromatograph/mass spectrograph. Proposals recommending the application of a comprehensive hospital waste management system are presented that will ensure that any potential risks hospital wastes pose to public health and to the environment are minimized.
A simple, novel method for improving the electrochemical response of Sn in lithium cells is proposed that involves preparing Sn by a reduction procedure in the presence of Mo powders. Four different Mo x Sn1− x mixtures (0< x <0.26) were electrochemically tested and their structural and textural properties determined by using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of the resulting composites in lithium cells were studied by galvanostatic, step potential electrochemical spectroscopy (SPES) and electrochemical impedance spectroscopy (EIS) measurements. The mixtures were found to consist of crystalline Sn and Mo; however, the presence of the latter element modified the Sn habit in two ways, namely, by significantly decreasing particle size and increasing the reactivity towards oxygen. Although Mo is inert towards lithium, it increased both the discharge capacity and the capacity retention of the electrode in relation to pure Sn. The improved interparticle connectivity, reduced electrolyte decomposition and decreased charge-transfer resistance observed in the Mo-containing samples appear to be beneficial effects of the addition of Mo.
We report here an interesting observation on the electrochemical performance of hematite nanoparticles derived from cubic maghemite nanoparticles and hexagonal goethite rods prepared by a sonochemical process. We prepared hematite (α-Fe2O3) particles by annealing the as-prepared spherical cubic maghemite (γ-Fe2O3) nanoparticles and rod shaped hexagonal goethite (α-FeOOH) particles at 600 °C in air and investigated their performance as a Li-ion battery anode. Interestingly, annealing of spherical maghemite particles resulted in the formation of plate like interconnected hematite particles exhibiting unimodal pore distribution whereas rod shaped goethite has resulted in the formation of irregularly shaped porous hematite particles having a wide and multimodal pore distribution. The plate like α-Fe2O3 cells delivered a reversible capacity of ∼1160 and the porous α-Fe2O3 nanoparticles exhibited a slightly lower capacity of ∼1100 mAh g–1. The test cells rendered a reversible capacity of ∼926 and ∼841 mAh g–1 for nanoparticles derived from maghemite and goethite, respectively, after 40 galvanostatic cycles and a capacity of 611 and 522 mAh g−1 at 0.1C rate after 100 cycles. In other words, the investigated α-Fe2O3 nanomaterials retained a reversible capacity of ∼80 and 75%, respectively after 40 galvanostatic cycles. The basic difference in the electrochemical performance of the studied hematite particles have been attributed to the difference in the porosity of the samples. Moreover, the adopted synthesis technique is very simple and easily up scalable compared to most of the methods available in the literature for the synthesis of hematite nanoparticles.
In comparison to pure electric vehicles (EV) the opportunities for hybrid electric vehicles (HEV) are much better, since range restrictions no longer apply and the interaction of the internal combustion engine and electrical drive bring increased energy efficiency and environmental friendliness. The batteries used in such applications must meet very high standards in terms of performance and service life. Although the battery capacity is smaller than for a purely EV, it needs to be able to generate far higher levels of power. The technical challenges of hybrid applications have led to the development of high-performance batteries. At the forefront of these is the nickel-metal hydride system (NiMH). With specific power and energy data in the range from 300 to 900W/kg, 55 to 37Wh/kg, respectively (based on cell weight), excellent charge efficiency and energy throughput levels of more than 10,000 times the nominal energy, the NiMH system comes very close to satisfying the needs of the HEV. Parallel developments with the lithium-ion system based on manganese spinel as cathode material show that, with specific power and energy levels above 1000W/kg, 50Wh/kg, respectively, this technology will also be able to play an important role in the future. Service life figures in terms of calendar life have been improved tremendously to about three years, but there is still a need for further improvement in order to meet the specifications of car manufacturers. For this reason, an increase of life span is the subject of intensive development work.
Nano-scaled SnO2–V2O5 mixed oxide is synthesized by a hydrothermal method in an autoclave. For comparative evaluation, V2O5 single oxide is prepared by a conventional process from ammonium vanadate. The capacitive behaviour of the following electrodes is studied by cyclic voltammetry in 0.1M KCl solutions: carbon nano-tubes (CNT), V2O5, V2O5–CNT, and SnO2–V2O5–CNT. At a scan rate of 100mVs−1, the SnO2–V2O5–CNT electrode provides the best performance, viz., 121.4Fg−1. The nano-scaled mixed oxide is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Raman spectra.
The commercial Li4Ti5O12 is co-modified using Mg2+ and F⿿ via a co-precipitation method with the purpose of understanding the reaction mechanism of the fluoride modification process. For comparison, the commercial Li4Ti5O12 is also modified using Mg2+ and F⿿, respectively. After the co-modification process, F⿿ reacts with Li4Ti5O12 chemically to generate new impurity phase such as anatase TiO2, rutile TiO2 and LiF, while Mg2+ forms MgO coating layer on the Li4Ti5O12 particles. The capacity and rate capability of the Li4Ti5O12 have been improved after the 1wt% Mg2+ and F⿿ co-modification. The charge capacity of the Mg2+ and F⿿ co-modified Li4Ti5O12 at 0.5C, 1C, 3C, 5C and 10C rate in the range of 0 ⿼3V is 234.1, 218.6, 200.8, 182 and 148mAh g⿿1, respectively. Meanwhile, the electrolyte reduction decomposition on the Li4Ti5O12 was suppressed after the co-modification process, thereby enhancing the cycling performance of the Mg2+ and F⿿ co-modified Li4Ti5O12. In particular, the 3 wt% Mg2+ and F⿿ co-modified Li4Ti5O12 keeps 74.5% charge capacity after 200 cycle charge-discharged test at a high rate of 5C, which is higher than the commercial Li4Ti5O12 (58.7%).
Electrochemical energy storage technology is based on devices capable of exhibiting high energy density (batteries) or high power density (electrochemical capacitors). There is a growing need, for current and near-future applications, where both high energy and high power densities are required in the same material. Pseudocapacitance, a faradaic process involving surface or near surface redox reactions, offers a means of achieving high energy density at high charge–discharge rates. Here, we focus on the pseudocapacitive properties of transition metal oxides. First, we introduce pseudocapacitance and describe its electrochemical features. Then, we review the most relevant pseudocapacitive materials in aqueous and non-aqueous electrolytes. The major challenges for pseudocapacitive materials along with a future outlook are detailed at the end.
This work demonstrates the effect of atomic layer deposited (ALD) Al2O3 on the reactivation of dissolved polysulfides in Li–S batteries. A 0.5nm thick layer of Al2O3 is conformally coated onto highly porous carbon cloth by ALD, and then assembled in a Li–S battery between the sulfur cathode and the anode side (separator and Li anode) to function as a reactivation component. Compared to half cells with no ALD treatment, the ultrathin Al2O3 coating increases the specific discharge capacity by 25% from 907 to 1136mAh/g at the 1st cycle, and by 114% from 358 to 766mAh/g at the 40th cycle. Thus the ALD-Al2O3 improves the initial specific capacity and stabilizes the cycle life remarkably. Scanning electron microscopy and energy-dispersive X-ray spectroscopy results indicate that the ALD-Al2O3 coated carbon cloth sorbs (adsorbs/absorbs) more dissolved sulfur species from the electrolyte. Potential mechanisms for the improved sorption properties are proposed. The combination of an ultrathin ALD-oxide coating with highly porous carbons presents a new strategy to improve the performance of Li–S batteries.
Lithium ion batteries experience diffusion-induced stresses during charge and discharge processes which can cause electrode failure in the form of fracture. Previous diffusion-induced stress models and simulations are mainly based on simple active material particle structures, such as spheres and ellipsoids. However, the simple structure model cannot reveal the stress development in a real complex lithium ion battery electrode. In this paper, we studied the diffusion-induced stresses numerically based on a realistic morphology of reconstructed particles during the lithium ion intercalation process. The morphology of negative and positive active materials of a lithium ion battery was determined using X-ray micro/nano computed tomography technology. Diffusion-induced stresses were simulated at different C rates under galvonostatic conditions and compared with spherical particles. The simulation results show that the intercalation stresses of particles depend on their geometric characteristics. The highest von Mises stress and Tresca stress in a real particle are several times higher than the stresses in a spherical particle with the same volume.
A Li-ion capacitor (LIC), typically composed of a pre-lithiated negative electrode and an activated-carbon positive electrode, can provide high energy and power density. In this work, we compare the electrochemical performances of pre-lithiated graphene nanosheets and conventional graphite as negative electrode materials for LICs. The LICs employing pre-lithiated graphene nanosheets show a specific capacitance of 168.5 F g−1 with 74% capacitance retention at 400 mA g−1 after 300 cycles. Moreover, the capacitors deliver a maximum power density of 222.2 W kg−1 at an energy density of 61.7 Wh kg−1, operated in the voltage range of 2.0–4.0 V. Therefore, pre-lithiated graphene nanosheets are promising negative electrode materials for high power LICs.