batterydata/paper-abstracts huggingface dataset:
In terms of understanding and tuning the optoelectronic behavior of 3rd generation solar cells, such as quantum dot (QD)-sensitized solar cells, QD-based heterostructures represent an excellent and relevant model system and opportunity for analyzing exciton dissociation and charge separation across a well-defined nanoscale interface. In particular, because QDs possess a tunable bandgap and the capability of initiating multi-electron exciton generation, QD-based components tend to be incorporated within optical-related devices, including photovoltaics, light emitting diodes, photoelectrochemical devices, photosensors, and phototransistors. The community has collectively expended significant effort in terms of creating, formulating, and optimizing novel forms of heterostructures comprised of QDs, immobilized by predominantly chemical means onto one-dimensional (1D) motifs, such as but not limited to carbon nanotubes (CNTs) and carbon nanofibers (CNFs). In so doing, it has been noted that key physical variables such as but not limited to (a) QD size, (b) QD loading and coverage, as well as (c) ligand identity can impact upon optoelectronic behavior of CNT-based heterostructures. In recent years, work has extended towards analyzing the optoelectronic ‘cross-communication’ between QDs with related, adjoining 1D semiconducting metal oxides, metal chalcogenides, and metal fluorides. In these examples, other important factors that also are relevant for determining the optical properties of these more generalized classes of heterostructures include parameters, such as (i) morphology, (ii) surface coverage, (iii) chemical composition of the underlying platform, (iv) QD identity, (v) luminescence properties of activating species, as well as (vi) the identity and concentration of dopant ions. In other words, to alter, manage, and manipulate the charge versus energy transfer channels within these materials in a deterministic manner requires basic insights into the close correlation and interplay between physical structure, chemical bonding, and observed performance.
Recent work found that renewable energy could supply 80% of electricity demand in the contiguous United States in 2050 at the hourly level. This paper explores some of the implications of achieving such high levels of renewable electricity for supply chains and the environment in scenarios with renewable supply up to such levels. Expanding the renewable electricity supply at this scale by 2050 implies annual capacity additions of roughly 20gigawatts per year (GW/year) over the next decade, rising to roughly 40GW/year from 2040 to 2050. Given total 2012 renewable electricity capacity additions of slightly more than 16 GW, this suggests moderate growth of the related supply chains, averaging overall roughly 4% annual growth to 2040. Transitioning to high renewable electricity supply would lead to significant reductions in greenhouse gas emissions and water use, with only modest land-use implications. While renewable energy expansion implies moderate growth of the renewable electricity supply chains, no insurmountable long-term constraints to renewable electricity technology manufacturing capacity or materials supply areidentified.
Low conductivity and stability of anion exchange membranes limited the durability and performance of corresponding fuel cells despite their unique advantages in compared to the proton exchange membrane fuel cells. In this work, we present a simple and efficient method to fabricate highly durable anion exchange membranes from commercial porous hydrocarbon substrates. Polyethylene/polypropylene (PE/PP) microfibers is employed as a substrate and radiation induced emulsion grafting is utilized to introduce poly(vinylbenzyl chloride) side chains. The grafted substrates with flexible content of side chains are converted to anion exchange membranes by converting into dense membranes and introducing quaternary amine groups. The dense membranes are characterized and employed in vanadium redox flow battery (VRFB) application. Developed membranes demonstrate high anion conductivity, low vanadium permeability and good chemical and mechanical stability. In compare to Nafion 117, superior performance is achieved for the developed membranes as the undesired vanadium ion permeability is reduced by 16 times and the energy efficiency significantly enhanced by 9% at current density of 80 mA cm−2. Such enhanced performance of the developed membrane is attributed to the presence of positive charged ionic groups in the membrane structure.
Off-grid electrification is gaining importance in the developing countries where the access to electricity is often limited. The purpose of this paper is to review alternative methodologies that are used for off-grid electrification projects to identify the features of each methodological approach and to present their strengths and weaknesses. The paper reviews a large volume of relevant literature covering techno-economic feasibility studies, analytical works highlighting methodological applications and practice-oriented literature. The review identifies five methodological options, namely the worksheet-based tools, optimisation tools, multi-criteria decision-making (MCDM) tools, system-based participatory tools and hybrid approaches. The paper recommends a hybrid approach that combines two or more options to take advantage of strengths and weaknesses of different options.
Nitrogen-doped carbon nanotubes (N-CNTs) derived from ethylenediamine precursor have been used as air cathode catalyst for zinc-air batteries (ZABs) in half cell and single cell. Investigation of N-CNTs employed a rotating disc electrode system revealed excellent catalytic activity towards oxygen reduction reaction (ORR) in alkaline electrolyte. The influence of alkaline electrolyte concentration on single cell performance of ZABs has also been explored. The highest cell performance was achieved at an electrolyte concentration of 6M KOH, which resulted in a maximum cell power density of 69.5mWcm−2.
Li-ion battery technology has become very important in recent years as these batteries show great promise as power sources that can lead us to the electric vehicle (EV) revolution. The development of new materials for Li-ion batteries is the focus of research in prominent groups in the field of materials science throughout the world. Li-ion batteries can be considered to be the most impressive success story of modern electrochemistry in the last two decades. They power most of today's portable devices, and seem to overcome the psychological barriers against the use of such high energy density devices on a larger scale for more demanding applications, such as EV. Since this field is advancing rapidly and attracting an increasing number of researchers, it is important to provide current and timely updates of this constantly changing technology. In this review, we describe the key aspects of Li-ion batteries: the basic science behind their operation, the most relevant components, anodes, cathodes, electrolyte solutions, as well as important future directions for R&D of advanced Li-ion batteries for demanding use, such as EV and load-leveling applications.
Using Ag, Pb and Al as dopants, Ba0.95M0.05Li2Ti6O14 is fabricated as advanced anode candidate for repeated lithium storage. Owing to smaller ionic radius, Ag+, Pb2+ and Al3+ are successfully introduced into the lattice of BaLi2Ti6O14, which results in the formation of high purity Ba-site doped Ba0.95M0.05Li2Ti6O14 (M=Ag, Pb, Al). Compared with the pristine sample, M-doped BaLi2Ti6O14 exhibits higher reversible capacity, better rate capability and superior cyclability. Especially for Ba0.95Ag0.05Li2Ti6O14, it presents the best electrochemical property among all the as-prepared samples. It can deliver a high reversible charge capacity of 149.1mAhg−1 after 100 cycles at the current density of 100mAg−1 with capacity retention of 92.27%. In contrast, BaLi2Ti6O14 only provides a lithium storage capacity of 126.9mAhg−1 with capacity retention of 80.83%. In addition, its high structural stability and electrochemical reversibility are also demonstrated by in-situ X-ray diffraction observation. All these evidences show that metal doping may be an effective method to enhance the lithium storage capability of BaLi2Ti6O14. Especially for Ba0.95Ag0.05Li2Ti6O14, it can be used as possible anode candidate for rechargeable batteries.
General model for the description of electrochemical behavior of lithium ion intercalating materials is formulated on the basis of fundamental physicochemical principles. Kinetic and transport parameters for selected well-known electrode materials (LiMn2O4 and LiCoO2) are evaluated from numerical modeling and fitting of cyclic voltammetry responses. Good agreement between calculated and experimental voltammograms in the wide range of potential scan rates proved the self-consistency of the proposed model. The applied formalism allows for the correct choice of model assumptions and accurate determination of kinetic and transport parameters of intercalating materials.
To improve structural and electrochemical properties of LiMn2O4 thin films, cobalt ions were substituted for manganese ions by a co-sputtering method. The annealed films had the spinel-phase, which had a preferred orientation of (111). Compositions of the films were nearly the stoichiometric LiMn2O4 and LiCo0.26Mn1.74O4, respectively. In the electrochemical test, the discharge capacity of the LiCo0.26Mn1.74O4 film was lower than that of the LiMn2O4 film. However, cyclability of the LiCo0.26Mn1.74O4 film was better than that of the LiMn2O4 film. The cobalt ions effectively improved the structural and electrochemical properties of the spinel-phase LiMn2O4 thin films.
The economic, health, and environmental costs of kerosene, candles, and other fuel-based lighting are well-documented. As a result of efforts by the World Bank and other organizations, numerous lighting products incorporating solar photovoltaic and light-emitting diodes (LEDs) have been introduced in Sub-Saharan Africa. The category of solar portable lights is increasingly popular, in part because the lower retail price of these lights can make them more affordable to lower-income households. The UC Davis Lighting the Way Zambia project sought to explore the minimum costs and performance requirements for a solar portable light targeting candle and kerosene users in Zambia. This paper discusses the product design process, including the establishment of performance requirements and metrics, as well as a cost-optimization exercise used to evaluate key electronic components. The cost structure of the final design is presented with end-user costs and actual manufacturing costs. The results suggest that an 18-lumen solar portable light with a 4-h run time would meet many users’ needs and can be manufactured for less than US$9 per unit, with a cost of $0.34 per 1000 lm-h and a payback period of around 6 months.
A hollow spherical La0.8Sr0.2MnO3 (HS-LSM) perovskite oxide has been prepared using a new carbonate-template route, and characterized by XRD, SEM and TEM. SEM and TEM results show that the pre-prepared oxides consist of porous microspheres composed of submicrometer-sized subunits with a secondary particle diameter of ∼20–50 nm. The catalytic activity of the oxide for the oxygen reduction reaction (ORR) in 0.1 M KOH solution has been studied using a rotating ring-disk electrode (RRDE). In the ORR tests, a maximum cathodic current density of 6.4 mA cm−2 at −0.9 V (vs. Ag/AgCl) with 2500 rpm has been obtained, and the ORR mainly favors a direct four-electron pathway. The chronoamperometric test shows that the HS-LSM exhibits excellent stability for the ORR.
Lithium metal is an ideal anode material for lithium battery thanks to its ultra-high specific capacity and lowest redox potential. However, uncontrollable growth of lithium dendrites hinders its application due to local aggregation of lithium ions and anisotropic growth of lithium metal driven by uneven electric field distribution. Here a strategy is proposed to address this issue via utilizing porous equipotential body decorated with heterogeneous nucleation sites as advanced three-dimensional current collector. The conductive network of carbon nanofibers is recognized as a porous equipotential body, where the interior electric filed is zero due to the well-defined electric field shielding effect. In addition, copper nanoparticles as heterogeneous nucleation sites are uniformly anchored on carbon nanofibers, which guide lithium deposition evenly. As a result, lower impedance and higher Coulombic efficiency (∼97%) are achieved in modified lithium-copper cell. In particular, the cycling lifetime of modified symmetric lithium-lithium cell is expanded up to 500 cycles at extremely large current density of 50 mA cm−2.
Ion adsorption onto high surface area microporous Carbide Derived Carbons (CDCs) with pore sizes in the sub-nanometer range was studied by means of the Electrochemical Impedance Spectroscopy (EIS) technique in two electrolytes, Tetraethylammonium Tetrafluoroborate (NEt4BF4) in Acetonitrile (AN) and in Propylene Carbonate (PC). Polarization at two bias voltages (0.5V/Ref and −1V/Ref) for EIS measurements enabled comparing the capacitive behaviors resulting from anions and cations adsorption, respectively, it was confirmed that the effective size of NEt4 + is bigger than the one of BF4 −. Higher transport limitation was then observed for cations and was exalted in PC-based electrolyte. Although slow ion transport kinetics, it was found that the low frequency vertical line observed on the Nyquist plots was preserved meaning that carbon electrodes were fully charged. This study confirmed the importance of choosing an electrode carbon pore size adapted to the effective ion size. Finally, the best performances would be got in 1.5M NEt4BF4 AN-based electrolyte with a 0.76nm pore size negative electrode and a 0.68nm pore size positive electrode.
The battery industry sees a need to improve the adhesion strength between porous nickel plaques and substrates in sintered nickel electrodes in order to reduce the use of nickel and to achieve higher battery capacity. In this paper we report on the use of a thin buffer layer to enhance plaque/substrate adhesion. In particular, we have attempted to improve adhesion performance of conventional sintered plaques produced from filamentary Ni powders (INCO-255, particle size 2.2–2.8μm) through the introduction of a thin, intermediate layer made of finer Ni powders (INCO Type 110 and INCO Type 210, particle size 0.8–1.5μm and 0.5–1.0μm, respectively). The process consists of two steps. First, a buffer layer was applied from a slurry containing the finer Ni powders. After drying, the substrate was coated again with a slurry containing standard Type 255 powder. A vertical coating apparatus with periodically contacting blades was designed to produce thin, uniform buffer layers with low surface density (1–10mgcm−2). For adhesion testing, a tensile strength test specimen holder was modified to ensure planar loading of the interface. Significantly enhanced bonding between the plaque and substrate was observed due to the introduction of the buffer layer.
A low temperature molten salt process is developed to prepare crystalline Si nanoparticles through the reduction of micro-sized high silicon zeolite by metallic Al (or Mg) in molten AlCl3. The reaction can be initiated at 200 °C, and the yield is about 40%. As the reaction temperature increases to 250 °C, the yield can reach about 75%. When the prepared Si was used as an anode for Li-ion batteries, reversible capacities of 2663 mA h g−1 at 0.5 A g−1 after 50 cycles and 870 mA h g−1 at 3 A g−1 after 1000 cycles can be obtained. Similarly, this synthetic strategy is employed to synthesize Si nanoparticles starting from various abundant raw materials including SiO2 powder, kieselguhr, fiberglass, and even the natural mineral of albite.
While homoleptic magnesium dialkoxides (MgR2, R = alkoxide) have shown promise as precursors for magnesium-ion electrolytes, the effect of ligand steric bulk on the performance of electrolytes based on these compounds is not fully understood. Increasing steric hindrance, studied via R groups with additional phenyl moieties, produces electrolytes with sequentially lower deposition overpotentials (less than −90 mV), higher purity Mg deposits (ca. 100% Mg), and lower overall cell impedances. The two largest alkoxide ligands show consistent cycling behavior and low stripping and plating overpotentials over 200 constant-current plating/stripping cycles. A deep-red visual change and the presence of large solubilized magnesium particulates above 450 nm in size is observed in an electrolyte containing magnesium bis(triphenylmethoxide) and aluminum chloride in contact with an abraded magnesium anode. Further morphological and impedance characterization show that this electrolyte system rapidly activates the magnesium metal anode surface to produce low overpotentials and, as such, is a candidate for further investigation.
Ultrafine manganese oxide-decorated carbon nanofibers (MnOn-CNF, 1.3<n<2.0) as a new type of electrode materials are facilely fabricated by direct conversion of Mn, Zn-trimesic acid (H3BTC) metal organic framework fibers (Mn-ZnBTC). The construction and evolution of Mn-ZnBTC fibers are investigated by SEM and in situ high-energy XRD. The manganese oxides are highly dispersed onto the porous carbon nanofibers formed simultaneously, verified by TEM, X-ray absorption fine structure (XAFS), Raman, ICP-AES and N2 adsorption techniques. As expected, the resulting MnOn-CNF composites are highly stable, and can be cycled up to 5000 times with a high capacitance retention ratio of 98% in electrochemical capacitor measurements. They show a high capacitance of up to 179Fg−1 per mass of the composite electrode, and a remarkable capacitance of up to 18290Fg−1 per active mass of the manganese(IV) oxide, significantly exceeding the theoretical specific capacitance of manganese(IV) oxide (1370Fg−1). The maximum energy density is up to 19.7Whkg−1 at the current density of 0.25Ag−1, even orders higher than those of reported electric double-layer capacitors and pseudocapacitors. The excellent capacitive performance can be ascribed to the joint effect of easy accessibility, high porosity, tight contact and superior conductivity integrated in final MnOn-CNF composites.
The domain of ‘robotics’ is undergoing a major transformation in dimension as well as scope. Recent advances in various disciplines of technology have revolutionized this domain at an incredible pace far beyond the contemporary state of the art. Highlighting the forecasted population of robots in future and the resulting demand of massive energy consumption, this review addresses the application of renewable energy sources in uninterruptible supply for robots. The study analyzes the extensive field of renewable energy technology and discovers that comparing with traditional sources; green energies like solar, wind and biological have significant potential to drive robots. Listing the world-wide achievements attained by the applications of renewable energy technology for robots, the review finally presents the subject matter in context of Pakistan. It is shown that being rich in renewable energy resources, broad possibilities for robot technologies exist here. With a discussion on challenges to exploit this potential, suggestions are outlined. It is anticipated that wider dissemination of research developments in the integration of these streams will stimulate more exchanges and collaborations among the research community and contribute to further advancements.
Ceria-based composites are developed and considered as potential electrolytes for intermediate temperature hybrid fuel cell applications (IT-HFC). The structural properties of composite materials based on mixtures of gadolinia-doped ceria (GDC) and alkali chloride (LiCl-KCl) are analysed. The microstructure of the electrolyte is observed by scanning electron microscopy (SEM). High temperature and room-temperature X-ray diffraction allowed determining the precise structure of the composite and its regular and reversible evolution with the temperature. Finally, the electrical conductivity is determined by impedance spectroscopy and presented as a function of the electrolyte composition. The ageing behaviour after thermal cycling and at a constant temperature of 400°C shows that this material is very promising. After such conditions, conductivity of GDC/Li-K-Cl composite electrolyte is still close to 0.12 S.cm−1 at 400°C, which is more than the Li-K carbonate/GDC composite conductivity at 600°C under the same conditions.
Dielectric Elastomer Generators (DEGs) are promising devices able to convert mechanical to electrical energy by exploiting the variations in the capacitance of a deformable dielectric membrane. In this work the optimal performance of DEGs in-plane equibiaxial loading configuration is investigated. We analyze a four-stroke cycle which is chosen due to its simplicity and availability. Four failure modes of the DEG are accounted for: electric breakdown, electromechanical instability, ultimate stretch, and loss of the in-plane tensile state. Explicit expressions for the electromechanical fields in the membrane and the harvested energy are derived, and a constraint optimization procedure is employed to determine the optimal cycles. We find that if the electric breakdown strength is larger than a certain universal threshold value, the optimal cycle is independent of this parameter. This threshold value depends on the membrane ultimate stretch, and this dependence is different for low, moderate or high ultimate stretches. Analyses of DEGs with membranes belonging to the three regimes demonstrate that the DEG failure depends on the electric breakdown strength and the ultimate stretch. Accordingly, a diagram with six subregions corresponding to the type of failure is introduced as a design tool. DEGs with multi-layered membranes of two commercially available materials, an acrylic elastomer and a natural rubber, are considered. The number of layers is set according to a predefined load capacity parameter. We find that membranes with a moderate ultimate stretch ensure a cycle more efficient than those with high ultimate stretch, since a larger portion of the invested energy is converted.
Hollow nanostructured mixed metal oxides have recently been intensively investigated as electrode materials for energy storage and conversion due to their remarkable electrochemical properties. Although great efforts have been made, the synthesis of hollow nanostructured vanadium-based mixed metal oxides especially those with one dimensional structure is rarely reported. Vanadium-based mixed metal oxides are promising electrode materials for lithium-ion batteries with high capacity and good rate capability. Here, we develop a facile and general method for the synthesis of one dimensional MxV2O8 (M = Co, Ni, Fe) tubular structure through a simple single-spinneret electrospinning technique followed by a calcination process. As a demonstration, Co3V2O8 hollow nanofibers are evaluated as anode materials for lithium-ion batteries. As expected, benefiting from their unique one dimensional tubular structure, the as-synthesized Co3V2O8 exhibits excellent electrochemical properties for lithium storage. To be specific, it can deliver a high specific capacity of 900 mAh g−1 at 5 A g−1, and long cycling stability up to 2000 cycles. The present work makes a significant contribution to the design and synthesis of mixed metal oxides with one dimensional tubular structure, as well as their potential applications in electrochemical energy storage.