batterydata/paper-abstracts huggingface dataset:
Lithium-sulfur (Li-S) is one of the most promising next-generation lithium-ion battery systems due to its high theoretical specific capacity. However, Li-S batteries suffer from a short cycling life, poor mechanical stability and low coulombic efficiency. Developing a robust solid electrolyte interphase (SEI) plays a critical role in alleviating these issues. Current approaches for a robust SEI are mostly based on using additives, which negatively impact the energy density. Herein, newly developed electrochemical conditioning techniques were applied to study their effects on the formation of the SEI in Li-S batteries. The dynamic mechanisms in the battery associated with each conditioning technique were investigated using city and highway models based on real world driving conditions. City and highway models incorporated various electrochemical characterization techniques while introducing varying levels of cycling stress. As an additive free approach, the novel plateau targeted conditioning method improves Li-S SEI formation that increases battery capacity and cycling stability. This work will pave the way for the realization of additive free approaches to improving the performance of Li-S batteries.
This paper presents the design and control of a sustainable standalone photovoltaic (PV)-battery hybrid power system (HPS). The research aims to develop an approach that contributes to increased level of reliability and scalability for an HPS. To achieve such objectives, a PV-battery HPS with a passively connected battery was studied. A quantitative hardware reliability analysis was performed to assess the effect of energy storage configuration to the overall system reliability. Instead of requiring the feedback control information of load power through a centralized supervisory controller, the power flow in the proposed HPS is managed by a decentralized control approach that takes advantage of the system architecture. Reliable system operation of an HPS is achieved through the proposed control approach by not requiring a separate supervisory controller. Furthermore, performance degradation of energy storage can be prevented by selecting the controller gains such that the charge rate does not exceed operational requirements. The performance of the proposed system architecture with the control strategy was verified by simulation results using realistic irradiance data and a battery model in which its temperature effect was considered. With an objective to support scalable operation, details on how the proposed design could be applied were also studied so that the HPS could satisfy potential system growth requirements. Such scalability was verified by simulating various cases that involve connection and disconnection of sources and loads. The quantitative reliability analysis and verification results show that the proposed architecture with power control strategy provides a straightforward approach for designing a reliable and scalable PV-Battery HPS. Although PVs and batteries have been used in this paper, the design and control approach can be applied to other hybrid power systems (HPSs) that involve the connection of various power sources.
The irreversible capacity of disordered carbons, used as anodes of lithium-ion batteries, is known to result from their generally large surface area (leading to large volume of passivating layer) and from the presence of surface functional groups and of heteroatoms left from the precursor, which can react irreversibly with lithium. In this paper, we show that the irreversible capacity of disordered carbons can result from an additional mechanism: lithium trapping in the internal porosity. A series of carbon samples with low specific surface area and low heteroatom content has been investigated by X-ray diffraction, helium pycnometry, complex impedance spectroscopy and galvanostatic cycling. A clear correlation has been found between the irreversible capacity and the internal pore volume.
Recent evidence suggests the existence of progenitor cells in adult tissues that are capable of differentiating into vascular structures as well as into all hematopoietic cell lineages. Here we describe an efficient and reproducible method for generating large numbers of these bipotential progenitors—known as hemangioblasts—from human embryonic stem (hES) cells using an in vitro differentiation system. Blast cells expressed gene signatures characteristic of hemangioblasts, and could be expanded, cryopreserved and differentiated into multiple hematopoietic lineages as well as into endothelial cells. When we injected these cells into rats with diabetes or into mice with ischemia-reperfusion injury of the retina, they localized to the site of injury in the damaged vasculature and appeared to participate in repair. Injection of the cells also reduced the mortality rate after myocardial infarction and restored blood flow in hind limb ischemia in mouse models. Our data suggest that hES-derived blast cells (hES-BCs) could be important in vascular repair.
NiO films were prepared by chemical bath deposition and electrodeposition method, respectively, using nickel foam as the substrate. The films were characterized by scanning electron microscopy (SEM) and the images showed that their morphologies were distinct. The NiO film prepared by chemical bath deposition was highly porous, while the film prepared by electrodeposition was dense, and both of their thickness was about 1μm. As anode materials for lithium ion batteries, the porous NiO film prepared by chemical bath deposition exhibited higher coulombic efficiency and weaker polarization and its specific capacity after 50 cycles was 490mAhg−1 at the discharge–charge current density of 0.5Ag−1, and 350mAhg−1 at 1.5Ag−1, higher than the electrodeposited film (230mAhg−1 at 0.5Ag−1, and 170mAhg−1 at 1.5Ag−1). The better electrochemical performances of the film prepared by chemical bath deposition are attributed to its highly porous morphology, which shorted diffusion length of lithium ions, and relaxed the volume change caused by the reaction between NiO and Li+.
Oxygen reduction to hydroperoxide ion in a 0.5 mm-thick porous uncatalyzed carbon-polytetrafluoroethylene electrode has been studied by electrochemical impedance spectroscopy using different experimental conditions such as KOH concentrations from 1.0 to 6.0 M, constant applied potentials with steady cathodic current densities in the range 5–100 mA cm−2, O2 partial pressures of 0.21–1.0 atm and temperatures from 5.0 to 55.0°C. The Nyquist diagrams show a main semicircle, assigned to dominating charge transfer and weak adsorption, together with a low-frequency semicircle, assigned to diffusion. The parameters of the equivalent circuit have been related to structural aspects of the electrode. The fitting results indicate increasing an electroactive area towards the electrolyte side when the overpotential increases. The low-frequency behaviour, interpreted using the finite-length diffusion model, is ascribed to the diffusion of electrogenerated hydroperoxide ion through the electrode pores. The gas diffusion cathode apparently has higher electroactive area approaching the electrolyte side and also, some tortuous electrolyte channels penetrating some tens of microns into its porous structure. The increase in its double layer capacity with increasing KOH concentration, cathodic current density and temperature, is explained by a higher electroactive area due to an increase in the electrode wetting.
New thin lithium-ion batteries (LIBs) using a laminated film bag, an organic liquid electrolyte, and a mesophase-pitch-based carbon fiber (MCF) anode exhibited high discharge performance, a very low swelling under a high-temperature storage, and excellent safety performance. A 1.5M solution of LiBF4 in an ethylene carbonate (EC)/γ-butyrolactone (GBL) mixed solvent was found to be a promising liquid electrolyte for the thin LIBs because the electrolyte has a high flame point of 129°C, a high boiling point of 216°C, a low vapor pressure, and a high conductivity of 2.1mS/cm at −20°C. It was demonstrated that the thin LIB using B-doped MCF anode has a high energy density of 172Wh/kg, high rate capability, high capacity at −20°C, and a long cycle life of 500 cycles. The safety of thin LIBs under overcharging tests and oven tests was superior to that of conventional prismatic LIBs and PLBs. The very low swelling and the excellent safety performance were attributable to the stability of LiBF4–EC/GBL electrolyte against LiCoO2 cathode material.
We have applied the concept of heterogeneous doping [1] to prepare and examine composite electrolytes, consisting of silica particles, low molecular weight polyethylene glycol solvents and lithium perchlorate salt. These “soggy sand” electrolytes combine high ionic conductivities (on the order of mScm−1) and high Li transference numbers (typically 60–80%) with improved mechanical properties. They were characterized using differential scanning calorimetry, dc-polarization and ac-impedance spectroscopy, zeta potential measurements and viscosimetry. Oxide, size and concentration as well as solvent molecular weight were varied to better understand the influence of ceramic oxide fillers on the ion conduction in these systems. As regarding the filler content, we observe that both conductivity and transference number of Li+ start increasing already at low volume fractions of oxide particles, reach a maximum and subsequently decrease to low values. The percolating network is – after initial partial coarsening – found to be stable within the time periods of the measurements.
Doping heteroatoms into carbon nanomaterials will greatly enhance their physiochemical properties, however, it is still challenging to prepare doped nanocarbons in large-scale by economical ways for industrial applications. Here, we report the macroscopic-scale synthesis of a new class of nitrogen-doped carbonaceous nanofibers (N-CNFs) aerogels with diameter from tens to hundreds nanometers by a template-directed hydrothermal carbonization (HTC) process, where ultrathin tellurium nanowires (TeNWs) as templates and nitrogen-containing carbohydrates as carbon sources. High-temperature treatment and CO2 activation of the N-CNFs endow them with high conductivity and porosity, resulting in outstanding performances as electrode materials for electrocatalysts and supercapacitors.
Due to the incorrect or unknown noise statistics of a battery system and its cell-to-cell variations, state of charge (SOC) estimation of a lithium-ion series-connected battery system is usually inaccurate or even divergent using model-based methods, such as extended Kalman filter (EKF) and unscented Kalman filter (UKF). To resolve this problem, an adaptive unscented Kalman filter (AUKF) based on a noise statistics estimator and a model parameter regulator is developed to accurately estimate the SOC of a series-connected battery system. An equivalent circuit model is first built based on the model parameter regulator that illustrates the influence of cell-to-cell variation on the battery system. A noise statistics estimator is then used to attain adaptively the estimated noise statistics for the AUKF when its prior noise statistics are not accurate or exactly Gaussian. The accuracy and effectiveness of the SOC estimation method is validated by comparing the developed AUKF and UKF when model and measurement statistics noises are inaccurate, respectively. Compared with the UKF and EKF, the developed method shows the highest SOC estimation accuracy.
Nowadays renewable sources are being used as clean sources to generate electricity and to reduce the dependency on fossil fuels. The uses of renewable sources are being increased in electricity generation and contributed to reduce the greenhouse gas emission. The function of any electrical power system is to connect everyone sufficiently, clean electric power anywhere and anytime of the country. This can be achieved through a modern power system by integrating electrical energy from clean renewable sources into the nation's electric grid to enhance reliability, efficiency and security of the power system. The paper on the status of review the driving force of the generation of renewable energy and proposing electrical energy generation from renewable sources to be ensured at least 20% of total energy of Australia. This paper has been studied the existing electricity generation capacity of Australia from renewable and non-renewable sources. Optimal electricity generation from renewable sources has been examined. The environmental impact of electricity generation from renewable sources has been considered. Under this paper the yearly average wind data of past 20 years and above for some meteorological stations of Australia have been used. The prospective electricity generation from wind turbines and solar photovoltaic panels has been proposed in the paper that will increase electrical energy of the power grid of Australia. It was estimated the capital cost of prospective electricity generation farms from wind and solar PV sources.
Si doped-poly(ethylene glycol) (Si-PEG) hybrid polymer electrolyte with SiOC bonds in the main chain obtains high ionic conductivity even at room temperature because of the more flexible molecule chains. In this work, poly(ethylene glycol)-borate ester (B-PEG) is further covalent bonded into the crosslinked Si-PEG network to form the hybrid solid polymer electrolyte (HSPE). Comparing to previous works in which B-PEG is just added as a plasticizer, the Lewis acidity of boron (B) in the network of polymer chains is less shielded by the connected PEG chains, which is more effective to improve lithium ion transference number ( t L i + ) and reduce the interfacial polarization of LiFePO4/HSPE/Li cells by attracting the anions of lithium salt. The t L i + increases monotonously along with the increase of B-PEG contents in HSPE, while the ion conductivity has a peak value. When B-PEG content is 23.1 wt%, the highest ionic conductivity of the hybrid polymer electrolyte reaches up to 1.6 × 10−4S/cm and t L i + is 0.68 at 25 °C. And the initial capacity of LiFePO4/HSPE/Li cells are 120 mAh/g and 90 mAh/g at 0.5C and 1C at 25 °C. After 100 cycles under 1C at 25 °C, the capacity retention of the LiFePO4/HSPE/Li cell is 84%, which is higher than that of 65% for LiFePO4/PSPE/Li cell. (PSPE indicates the Si-PEG polymer electrolytes with B-PEG just as plasticizer).
A natural field experiment found that real-time feedback on energy consumption while showering led to an 11.4% reduction in energy use in a random sample of hotel guests, demonstrating the potential for activity-specific feedback as a cost-effective and scalable conservation strategy.
Electrochemically active species in aluminum (Al) electrodeposition baths using AlCl3 and less volatile solvents i.e. glymes were investigated. Raman spectroscopy revealed that all the glyme baths contained AlCl4 − anions and Al-Cl-glyme cations as ionic species. Room temperature conductivities were as high as the order of 10−3 Scm−1 for the diglyme (G2), triglyme (G3) and tetraglyme (G4) baths, whereas that for the butyl diglyme (butylG2) bath was only 10−4 Scm−1 due to a lower concentration of ionic species. Surprisingly, electrochemical measurements showed that, among the glyme baths, only the G2 bath enabled electrodeposition of Al. Consequently, despite the similar structures of Al-Cl-glyme complex cations, only the G2 complex cations are electrochemically active. This suggests that the desolvation of glymes from Al-Cl-glyme cations and their subsequent reduction is exceptionally easy for the G2 complexes.
The effects of methylene methanedisulfonate (MMDS) on the high-temperature (~50 °C) cycle performance of LiMn2O4/graphite cells are investigated. By addition of 2 wt% MMDS into a routine electrolyte, the high-temperature cycling performance of LiMn2O4/graphite cells can be significantly improved. The analysis of differential capacity curves and energy-dispersive X-ray spectrometry (EDX) indicates that MMDS decomposed on both cathode and anode. The three-electrode system of pouch cell is used to reveal the capacity loss mechanism in the cells. It is shown that the capacity fading of cells without MMDS in the electrolytes is due to irreversible lithium consumption during cycling and irreversible damage of LiMn2O4 material, while the capacity fading of cell with 2 wt% MMDS in electrolytes mainly originated from irreversible lithium consumption during cycling.
Amorphous sodium-containing titanium phosphate (sample TiP), obtained by heating a disordered precursor at 300°C under air, electrochemically reacts with lithium by means of non-aqueous lithium cells. Discharge curves of EC/DEC cells in the 3.5–1.5V region, were different to that observed for NASICON titanium phosphates but the related capacity can be associated to the reduction of Ti4+ to Ti3+. Another sample, C-TiP, obtained by using nitrogen atmosphere during the thermal treatment, was able to provide 75% more capacity in this region. This sample contained carbon because of the incomplete pyrolysis of the surfactant present in the precursor. Carbon is supposed to stay occluded inside the pores considering the values of pores surface area, total conductivity and HRTEM measurements. These titanium phosphates were also tested as negative electrodes. Electrochemical impedance spectroscopy measurements suggest that both titanium phosphates are reduced to yield titanium, lithia and phosphorus at 0.0V. In our opinion, the presence of carbon in C-TiP is the key factor for the enhanced reactivity in the 3.2–1.5V region but is not enough to obtain a good electrochemical performance, in terms of cycling efficiency.
Tariff structures and network constraints might incentivize storing solar energy in the home to reduce reliance on utilities. This study shows that storing solar energy rather than exporting it to the utility grid could increase electricity consumption as well as CO2, SO2 and NOx emissions.
The objective of this experiment was to determine the factors influencing the transpiration rates of mature, clonal tea (Camellia sinensis L.) and estimate its transpiration efficiency. The heat pulse technique was used to measure transpiration rates of tea plants growing in the field as part of extensive canopies at Talawakelle, Sri Lanka during the period between 1 January and 19 February 1997. Irrigation and shading treatments were used to determine the influence of soil water content (S) and irradiance on transpiration rate. The transpiration rate declined only slightly when S decreased from field capacity (44%) to 33%. However, when S declined below 33%, the transpiration rate showed a rapid decline from 1.6 to 0.7l per plant per day at 15% S. When S was near field capacity, maximum transpiration rates of 0.53–0.93l plant−1 h−1 occurred between 1000 and 1500h. The corresponding maxima when the S was near permanent wilting point (i.e. at −1.5MPa matric potential) were 0.27–0.53l plant−1 h−1. Transpiration decreased linearly with decreasing irradiance throughout the range of radiation levels tested (i.e. from 100 to 15% of full sunlight) at a rate of 0.031l per plant per day per % reduction in solar irradiance. The daily transpiration rates of tea plants (0.42–1.07l per plant per day) under the natural shade of Grevillea robusta were considerably lower than the value of tea plants in the open, 3.511l per plant per day. Spraying of an antitranspirant, Kaolin, decreased canopy temperature by 2–4°C and especially around mid-day. Kaolin also decreased transpiration slightly during the period between 1000 and 1500h. Transpiration efficiency (T E) was 9.637kgha−1 (made tea) mm−1 of water transpired. The relationship between total dry matter yield and the ratio between transpiration and mean saturation vapour pressure deficit also was linear with a proportionality constant of 6.9gkg−1 kPa.
Sodium ion batteries have a huge potential for large-scale energy storage for the low cost and abundance of sodium resources. In this work, a novel structure of ultrafine polycrystalline TiO2 nanofibers is prepared on nickel foam/carbon cloth by a simple vapor deposition method. The as-prepared TiO2 nanofibers show excellent performance when used as anodes for sodium-ion batteries. Specifically, the TiO2 nanofibers@nickel foam electrode delivers a high reversible capacity of 263.2 mAh g−1 at 0.2 C and maintains a considerable capacity of 144.2 mAh g−1 at 10 C. The TiO2 nanofibers@carbon cloth electrode also shows excellent high-rate capability, sustaining a capacity of 148 mAh g−1 after 2000 cycles at 10 C. It is believed that the novel nanofibrous structure increases the contact area with the electrolyte and greatly shortens the sodium ion diffusion distance, and meanwhile, the polycrystalline nature of nanofibers exposes more intercalation sites for sodium storage. Furthermore, the density functional theory calculations exhibit strong ionic interactions between the exposed TiO2 (101) facets and sodium ions, leading to a preferable sodiation/desodiation process. The unique structural features endow the TiO2 nanofibers electrodes great advantages in rapid sodium storage with an outstanding high-rate capability.
A graphene/NiO composite was prepared by simple chemical precipitation followed by thermal annealing. The results of XRD, FT-IR, FE-SEM, FE-TEM, and EDS analyses confirmed the presence of NiO nanoparticles with plate structure on the graphene surface. The discharge capacities of graphene, graphene/NiO (37wt.%), and graphene/NiO (59wt.%) are about 302, 604, and 856mAhg−1 at 5000mAg−1 (5C), respectively. The cells containing 59wt.% NiO show the best performance, and the graphene nanocomposite materials have high rate properties that are comparable to some of the best results reported in the literature using NiO. This graphene/NiO (37 and 59wt.%) nanocomposite displays superior LIB performance with large reversible capacity, high Coulombic efficiency, good cyclic performance, and excellent rate capability, highlighting the importance of the anchoring of nanoplate structure NiO on graphene sheets for maximum utilization of electrochemically active graphene/NiO for energy storage applications in high-performance LIB.
Piezoelectric composites of PU/PZT with 0–3 connectivity were prepared in the film form. Homogeneous dispersion of the ceramic PZT in polyurethane matrix has been obtained and has been verified by SEM analysis. Dielectric properties reveal that under an electrical field of 1000 V the remnant polarization increased from 1.9 to 4 µC/cm−2 when the volume fraction of PZT increased from 50 to 80 %. Modeling and vibratory energy harvesting tests has been realized. At very low frequency and deformation, and without application of any static electric field, 1.15 µW of power has been obtained. The results obtained in this work contribute to demonstrate the ability of the incorporation of PZT particles in the polymer matrix to improve the conversion efficiency of the vibratory energy into electrical energy for the development of µ-generators.