batterydata/paper-abstracts huggingface dataset:
A novel micro-channel heat pipe array incorporated with crystalline silicon (c-Si) solar photovoltaic/thermal system (MHP-PV/T) was designed and constructed by the authors. The proposed design configuration combined c-Si solar cells and wide micro-channel heat pipes (MHP) that were filled with prescribed amount of acetone as refrigerant under a vacuum condition in the same insulated frame to simultaneously provide electrical and thermal energy. Heat and mass transfer characteristics of the MHP-PV/T were preliminary investigated using both numerical and experimental methods. The transient behavior and parametric heat transfer limitations of the heat pipe were also examined using MATLAB. A linear relation between the thermal instantaneous efficiency η th and the reduced temperature parameter ( T out - T in ) G T - 1 was established. The maximum instantaneous efficiency was found to be 54.0% with an electrical power output of 70W. The results indicated that the daily thermal and electrical efficiencies were 50.7% and 7.6%, respectively. The transient behavior of the MHP shows a faster thermal response to heat input within the temperature range of 48.8–49.2°C and slower response when the thermal diffusivity was reduced to 0.05cm2/s. The results also reveal good agreements between model simulation and experimental measurement with sufficient confidence.
We examine whether and how the inflow of female immigrants who specialize in household production affects the labour supply of Italian women. To identify the causal effect, we exploit the family reunification motives and network effects (i.e., the tendency of newly arriving female immigrants to settle in places where males of the same country already live) which is used as an instrument for the geographical distribution of female foreign workers. We find that when the number of immigrants who provide household services is higher, native Italian women spend more time at work (intensive margin) without affecting their labour force participation (extensive margin). This impact is concentrated on highly skilled women whose time has a higher opportunity cost. These results also hold after a battery of robustness checks. We present some further evidence that is also consistent with the idea that the impact works through substitution in household work rather than complementarities in the production sector. Finally, we show that immigration arises as a substitute to publicly provided welfare services, although this phenomenon raises concerns regarding the fairness and sustainability of this private and informal welfare model.
Spirally wound 12-V valve-regulated lead-acid batteries were subjected to conventional-charge and rapid-charge cycling tests. The cycle life was 250 cycles for the conventional-charge regime and 1000 cycles for the rapid-charge regime. In conventional-charge cycling, the positive active material quickly expanded and developed a coralloid structure in association with lowered utilisation and integrity. In rapid-charge cycling, no coralloid structure developed and the expansion was smaller and much slower. Correspondingly, the particle size of the negative active material grew in both cycling tests, but at a much slower rate in rapid-charge cycling. With the expansion of the positive active material, the negative active material was compressed. In the failed batteries, about one-third of the negative active material in the centre of the electrode was compressed almost into a solid non-porous mass. This densification process also occurred at a much slower rate in rapid-charge cycling. At the point of failure, the discharge capacity of all test batteries was limited by the negative electrode, although it was limited by the positive electrode at the beginning of the cycling tests. The cause of failure for most of the batteries, regardless of the charging regime, was the occurrence of “soak-through” shorts caused by numerous minute lead dendrites formed in the separator. This might have been encouraged by the formation of shorter distances between the two electrodes, created by the compression of the separator as a result of the expansion of the positive active material.
In the present study, Li2B4O7/LiBO2/Li3BO3 (LBO) nanocomposites were synthesized by a modified Pechini sol-gel route utilizing the mixture of different polybasic acids and gelling agents. This work demonstrated that by controlling the reaction variables including kind of polybasic acids and gelling agents, pH and mole ratio of polybasic acid to total metals, the LBO nanostructures with various morphologies and particle sizes were prepared. Furthermore, the LBO nanocomposites showed excellent TOC removal (70%) and photocatalytic efficiency (91%) in order to photodegradation of acid violet 7 azo dye as water pollutant under UV light irradiation. Moreover, compared to commercial P25 photocatalyst, the LBO heterostructures exhibited higher photodegradation activity for removal of acid violet 7 dye in 90 min under UV light irradiation, even after four times cycles. The excellent photocatalytic degradation of LBO photocatalyst can be ascribed to the strong photon absorption, high-efficiency charge carrier separation, uniform particle size and appropriate band gap energy of the nanocomposite. Also, radical trapping capability test exhibited that the photoinduced superoxide radicals (•O2 −) and holes (h+) were the prevailing active species in the photocatalytic performance.
Nickel hydroxide has shown extraordinary promise for hybrid supercapacitors because of the high theoretical capacity and low cost, but is usually limited by its low power density and complex synthetic process. Here, we report the design of a self-assembly three-dimensional (3D) porous Ni(OH)2 for high-performance energy storage through a simple, cost-effective, and environmentally friendly solvothermal-precipitation method. The 3D structure with interconnected network provides superior electron transportation properties, and the hierarchical porous architecture facilitates quick ion diffusion. The Ni(OH)2 obtained at 250 °C delivers a high capacitance of 2110 F g−1 at 1.0 A g−1 and a moderate cycling stability with 53% of the maximum specific capacitance over 2000 cycles at 5.0 A g−1. Additionally, on integration of the prepared Ni(OH)2 with hierarchically porous carbons as negative electrode material, the hybrid supercapacitor device delivers a high capacitance of 115 F g−1 and a high energy density of 40.9 W h kg−1 at a power density of 405 W kg−1. This study not only provides a simply controllable growth method of the unique self-assembly 3D porous Ni(OH)2 with high performance but also opens up a new approach to prepare various metallic oxides/hydroxides with excellent performance for highly promising practical energy-storage systems.
The purpose of the present study was to examine primary school teachers’ epistemological beliefs and teaching efficacy beliefs about mathematics and the relationship between these two constructs. Two paper and pencil questionnaires were administered to 184 in-service and pre-service teachers. Exploratory factor analysis yielded five epistemological factors that were labelled: simplicity of knowledge, certainty of knowledge, innate ability, source of knowledge, and speed of learning. Participants in general stated quite efficacious to teach mathematics. The regression analysis showed that epistemological beliefs predict teaching efficacy beliefs and vice versa. Implications of these findings concerning the teaching and learning process are discussed.
With the ever-growing need for lithium-ion batteries, particularly from the electric transportation industry, a large amount of lithium-ion batteries is bound to retire in the near future, thereby leading to serious disposal problems and detrimental impacts on environment and energy conservation. Currently, commercial lithium-ion batteries are composed of transition metal oxides or phosphates, aluminum, copper, graphite, organic electrolytes with harmful lithium salts, polymer separators, and plastic or metallic cases. The lack of proper disposal of spent lithium-ion batteries probably results in grave consequences, such as environmental pollution and waste of resources. Thus, recycling of spent lithium-ion batteries starts to receive attentions in recent years. However, owing to the pursuit of lithium-ion batteries with higher energy density, higher safety and more affordable price, the materials used in lithium-ion batteries are of a wide diversity and ever-evolving, consequently bringing difficulties to the recycling of spent lithium-ion batteries. To address this issue, both technological innovations and the participation of governments are required. This article provides a review of recent advances in recycling technologies of spent lithium-ion batteries, including the development of recycling processes, the products obtained from recycling, and the effects of recycling on environmental burdens. In addition, the remaining challenges and future perspectives are also highlighted.
Publisher Summary This chapter discusses that significant advances in our understanding of the photochromic properties of naphthopyrans that have been made in the past decade Such is the structural diversity of naphthopyrans now available that it is possible to achieve almost any shade of any color. Furthermore, control of the fade rate with half-lives of less than a second to many hours is possible, thereby supplementing the fast and strong coloration and increasing the potential applications of these long-lived materials. Their facile synthesis from readily available precursors has allowed the commercial development of naphthopyrans to proceed at a good pace through the efforts of a small number of research groups linked to international manufacturers. The major end user is the ophthalmic industry. Brown or grey sun lenses can now be based on a single photochromic naphthopyran, whereas less than 20 years ago, multicomponent lenses were the norm. Naphthopyrans are used in security inks and as identity markers in a variety of products. Future uses in cosmetic applications and as devices are under development.
Mesoporous carbon microspheres (MCMs) with tunable pore sizes have been prepared via a high-throughput spray drying-assisted hard template method and used as the hosts to load selenium (Se) for lithium-selenium (Li-Se) batteries. The pore size control of the MCMs (3.8, 5, 6.5, 9.5nm) was achieved by in-situ polymerized colloid silica templates with different sizes, thus prompting us to focus on tracing the effects of mesopore size on electrochemical performance of MCMs/Se cathodes. The results reveal that relative higher capacity and better cycling performance are presented in MCMs with smaller pores size due to the more effective confinement effect. At an optimal pore size of 3.8nm, the MCMs/Se with 50% Se loading delivers an initial capacity of 513mAhg−1 and capacity retention of 300mAhg−1 after 100 cycles at 0.5C. Furthermore, it is concluded that nitrogen doping could assist MCMs to retard the diffusion of polyselenide species possibly via an enhanced surface adsorption. The composites thus increase the reversible capacity by 30% after 100 cycles compared with the nitrogen-free composite. These results indicate that controlling pore structure and surface chemistry are good strategies to optimize the electrochemical performance of C/Se based cathodes for Li–Se batteries.
ABSTRACT Lithium-ion capacitors (LICs) are assembled with activated carbon (AC) cathode and pre-lithiated mesocarbon microbeads (MCMB) anode. The effect of AC cathode capacity design on the electrochemical performance of LIC is investigated by the galvanostatic charging-discharging and electrochemical impedance tests. As the designed capacity of AC positive electrode is lower than 50mAhg−1, the working potential of negative electrode is always in the low and stable plateau, which is conductive to the sufficient utilization and the working potential stability of positive electrode. When the designed capacity of positive electrode is higher than 50mAhg−1, the instability of negative electrode directly causes the reduced utilization and shortened working potential range of the positive electrode, which is responsible for the capacity attenuation and cycle performance deterioration of LIC. The positive electrode capacity design can realize the optimization of electrochemical performance of LIC. LIC50 exhibits the optimal electrochemical performance, high energy density up to 92.3Whkg−1 and power density as high as 5.5kWkg−1 (based on active material mass of two electrodes), excellent capacity retention of 97.0% after 1000 cycles. The power density and cycle performance of LIC can be further improved by reducing the AC positive electrode designed capacity.
Among the various energy storage systems, the rechargeable Zn–air battery is one of the most promising candidates for the consumer electronic market and portable energy sources. In a Zn–air battery, surface/interface chemistry plays a key role in their performance optimization of power density, stability and rechargeable efficiency. A Zn–air battery requires gas-involved ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) reactions, always leading to complex reactions and sluggish kinetic processes at the three-phase interface, in which rational surface/interface nanoengineering at the micro and meso-level play a decisive role. In this review, we cover the influence of surface/interface properties of electrocatalysts and air electrodes on the performance of rechargeable Zn–air batteries, and the latest surface/interface nanoengineering progress from the micro to meso-level is surveyed. Moreover, the surface/interface characteristics of electrocatalysts and air electrodes at the triple-phase interface, which are closely related to the four key parameters of electrical conductivity, reaction energy barrier, reaction surface area and mass transfer behavior, are also described in detail. Based on the discussion of the latest achievements of surface/interface nanoengineering, some personal perspectives on future advanced development of rechargeable Zn–air batteries are presented as well.
Battery electric buses (BEBs) are considered a promising alternative for bus fleets to alleviate the growing environmental problems in urban areas, and fast-charging technology has been introduced to BEB systems to help electric buses provide uninterrupted service without the need to carry a large onboard battery. The general consensus is that fast-charging may lead to high electricity demand charges, thus compromising the competitiveness of electric bus systems. However, a majority of current electric bus fast-charging station deployment models ignore these charges. The present study addresses this gap by explicitly considering the electricity demand charges in the optimal deployment problem of fast-charging stations for battery electric bus systems. The problem is formulated as a mixed integer linear programming model with the objective of minimizing the total cost of vehicle batteries, fast-charging stations, energy storage systems, and electricity demand charges. Numerical studies based on a real-world bus network in Salt Lake City, Utah, are conducted to demonstrate the effectiveness of the proposed model. The results show that the proposed model can effectively determine the deployment of fast-charging stations, the design of vehicle battery sizes, as well as the installation of energy storage systems. This study demonstrates that energy storage systems are a potential remedy for high demand charges from fast-charging.
This paper presents for the first time an impedance-based non-linear model for lead-acid batteries that is applicable in all operational modes. An overcharging model describes the accumulation and depletion of the dissolved Pb2+ ions. This physical model has been added to the earlier presented model to expand the model validity. To properly represent the charge acceptance during dynamic operation, a concept of “hardening crystals” has been introduced in the model. Moreover, a detailed gassing and oxygen recombination model has been integrated. A realistic simulation of the overcharging behavior is now possible. The mathematical description is given in the paper. Simplifications are introduced that allow for an efficient implementation and for model parameterization in the time domain. A comparison between experimental data and simulation results demonstrates the achieved accuracy. The model enhancement is of major importance to analyze charging strategies especially in partial-cycling operation with limited charging time, e.g. in electrically assisted or hybrid cars and autonomous power supply systems.
Synthesis, crystal structure and electrochemical reactivity of Li3CuFe3O7 in a lithium (Li) cell are reported as a new material for the first time. The crystal structure is γ-LiFeO2 type, and the chemical formula can be re-written as (Li0.714Cu0.286) (Li0.143Fe0.857)O2. The average charge–discharge voltages versus Li are 1.75/0.9V, which indicates the material may be used as a negative electrode in Li-ion batteries. The material demonstrates a discharge capacity of up to 970mAh/g, but shows also a significant irreversible capacity of >250mAh/g. It decomposes to very small particles of lithium oxide and unidentified species during the first discharge. The reversibility is strongly dependent on C-rate, electrode composition, initial particle sizes and/or crystallinity, implying that a better electrochemical performance may be achieved by adjusting these parameters. The observation of higher than theoretical capacity (694mAh/g) for the reversible reaction of Li3CuFe3O7+11Li↔7Li2O+Cu+3Fe, however, suggests the possibility that the Li–M (Cu, Fe) alloy formation–decomposition process is involved.
New types of dimensionally stable, flexible gel-type electrolyte membranes with a relatively wide electrochemical stability, high lithium ion conductivity and other desirable properties have been prepared by immobilizing N-n-butyl-N-ethylpyrrolidinium N,N-bis(trifluoromethane)sulfonimide-lithium N,N-bis(trifluoromethane)sulfonimide (Py24TFSI-LiTFSI), ionic liquid, IL, solutions in a poly(vinylidene fluoride)-hexafluoropropylene copolymer (PVdF-HFP) matrix. The addition of a discrete amount of ethylene and propylene carbonate (EC–PC), solvent mixture to the membranes resulted in an improvement of the ionic conductivity and in a stabilization of the interface with the lithium electrode. These IL-based gel type membranes can operate without degradation up to a temperature of 110°C where they reach conductivity values of the order of 10−2 Scm−1. All these properties make these polymer electrolyte membranes of interest for applications as separators in advanced lithium batteries.
This paper describes an application of the Strength Pareto Evolutionary Algorithm to the multi-objective optimization of a stand-alone PV–wind–diesel system with batteries storage. The objectives to be minimized are the levelized cost of energy (LCOE) and the equivalent carbon dioxide (CO2) life cycle emissions (LCE). Each solution of the Pareto front is a possible solution for the PV–wind–diesel-batteries system, which can supply the load, but each one has a different LCOE and LCE. Some solutions have low LCOE values, but high LCE values, and vice versa. Results show that the photovoltaic (PV) generator is the most important source of electrical energy for stand-alone systems in Spain and Southern Europe, not only environmentally, but also economically. In some cases, PV is almost the only source of energy, as some solutions of the best Pareto front do not include wind turbines and diesel generators run only a few hours during the year.
Due to a large variety of properties, passive films and their stability play an important role in recent and future research. At first, the nature of passive films is discussed for the steady state. New techniques allow the detailed determination of film thickness, stoichiometry, microstructure, and electronic properties. The distinction of these properties allows a rough classification of oxide films and their properties. In the second part, various processes, such as growth, reduction, dissolution, and modification are discussed. These overall processes depend on the rate of ion and electron transfer reactions (ITR, ETR) in a complex manner. Examples are given for some special reactions. Applications are discussed for surface protection, micro and nano systems and electrocatalysis.
Almost ten years after their first use in the photovoltaic (PV) field, perovskite solar cells (PSCs) are now hybrid devices that, in addition to having reached silicon performance, can accelerate the energy transition and boost the use of abundant elements for their manufacturing process. However, noble metals (in particular gold) represent the most typically used sources for back electrode fabrication, and this issue has been intensively considered by the research community in the last five years. This review shows how the most promising solution, considering also the need to develop a large-scale production process, is based on the use of carbon-based materials for the preparation of back electrodes. Graphite, carbon black, graphene and carbon nanotubes (CNTs) have been proposed, functionalized and characterized, leading to laboratory-scale solar cells and modules capable of providing excellent efficiencies and ensuring stability greater than those of gold-based devices. Strengthened by these results and its hydrophobizing properties, carbon has also started to be used as an electron transporting material (ETM), with excellent results on both rigid and flexible substrates. This review discusses the major advances and the updated state-of-the-art in the carbon-based PSC scenario, keeping a solid trajectory where the accessibility, low cost, high electrical conductivity, chemical stability and controllable porosity of carbon are highlighted and exploited in the design of upscalable hybrid solar cells.
Objective Major depression is a common concomitant of chronic central nervous system disorders, notably Parkinson’s disease (PD). Repetitive transcranial magnetic stimulation (rTMS) has been investigated as a potential treatment for depression in PD and for the movement disorder of PD, but comprehensive testing in multiple areas of performance has seldom been carried out within a single study. We studied the effect of left dorsolateral prefrontal rTMS on several different functional domains. Methods Fourteen PD patients with treatment-resistant depression entered an open, 10-day inpatient study of 10-Hz rTMS, undergoing extensive psychiatric, neuropsychological, and motor testing from baseline to 6 weeks after treatment. Motor testing included a defined “off” state. Results rTMS was well tolerated. Highly significant improvement in depression scores was seen 3 days and 3–6 weeks after treatment. Improvement was also found in anxiety, movement scores (especially in the off state), and some neuropsychological measures. We found no evidence of increased risk from rTMS in this population. Conclusions Further controlled trials of rTMS in PD appear worthwhile, and should include a defined “off” state. Significance TMS may be beneficial for depressed PD patients in multiple functional domains.