batterydata/paper-abstracts huggingface dataset:
The LiNi0.8Co0.15Al0.05O2 (NCA) cathode material is modified by electronically conductive antimony-doped tin oxide (ATO) nanoparticles via a facile wet chemical process. As observed by scanning and transmission electron microscopy, the ATO nanoparticles are homogeneously coated on the surface of NCA material. Thus-obtained ATO-coated NCA (ATO-NCA) material delivers a high discharge capacity of 145mAhg−1 at the current rate of 5C, which is significantly higher than that of pristine NCA material (135mAhg−1). Moreover, the capacity retention of ATO-NCA material is 91.70% after 200 cycles at the current rate of 1C and 60°C. In contrast, the pristine NCA only maintains 70.89% of its initial capacity after the same cycles. The substantially improved cyclability and rate capability are mainly attributed to the ATO coating layer, which can not only enhance the electron transport but also effectively restrain the side reactions between the NCA material and the electrolyte. More specifically, X-ray diffraction and photoelectron spectroscopy reveal that the ATO coating layer can restrain the Li+/Ni2+ disordering and the growth of SEI layer of NCA material, which are responsible for the improved cycling stability, especially at elevated temperatures.
An electric double-layer capacitor (EDLC) was tested using load tests involving charging/discharging at 60°C for 17h using an electrolyte consisting of a solution of 1moll−1 of tetraethylammonium tetrafluoroborate (TEA·BF4) in sulfolane (SL) in order to examine the deterioration of the properties of the EDLC, including its capacitance. The interactions between the molecules of the electrolyte and the surface of the activated-carbon electrode were investigated by solid-state 13C-MAS-NMR spectroscopy. The molecules (ions) adsorbed on the surfaces of the positive and negative electrodes and the free molecules (ions) in liquid phase were clearly detectable by solid-sate 13C-MAS-NMR. In the blank spectrum, corresponding to the electrode prior to the load test, four pairs of sharp and broad peaks could be observed. Two sharp peaks from the liquid-phase SL appeared at about 24ppm and 52ppm, respectively, and those for the adsorbed molecules on the electrode surface appeared at about 17ppm and 45ppm, respectively, both being shifted to a higher magnetic field by about 7ppm. The peak shapes of the latter two adsorbed molecules were much broader than those in liquid phase, suggesting stronger interaction with the electrode surface and restriction of molecular movement. Two pairs of such sharp and broad peaks could also be observed for the TEA molecule, which contained two types of carbon atoms. The chemical shifts of the peaks of the adsorbed molecules gradually shifted to a lower magnetic field after the load test at higher voltages ranging from 0.7V to 1.3V. Such changes in the chemical shift of adsorbed molecules were intimately related to the weaker adsorption forces acting on the adsorbed molecules, indicating that the electrode surface had been deteriorated by the load test at higher voltages. On the basis of these solid-state 13C-MAS-NMR spectra, the deterioration mechanism of the EDLC electrode at higher temperatures was discussed.
The publisher regrets that in the original printing of the above article Table 1 was printed incorrectly. The correct Table 1 is as follows. The publisher would like to apologise for any inconvenience this may have caused to the authors of this article/(and) readers of the journal.
Li3VO4-decorated Li4Ti5O12 (denoted as V-LTO) composites were synthesized via a facile one-pot cellulose-assisted combustion route. Homogeneous distribution of the Li3VO4 phase to introduce additional lithium ion transport paths in the composites and slight doping of vanadium into the lattice of Li4Ti5O12 phase were realized simultaneously through the one-pot synthesis, resulting in enhanced apparent ionic and electronic conductivity of the electrode materials. The product with optimal V content, i.e., V-LTO (1:8), showed much improved rate capacities compared with the pristine Li4Ti5O12. The effect of vanadium incorporation on the over-discharge capability of anode materials at a lower voltage was also studied, and the V-LTO (1:8) electrode demonstrated a capacity of 193.6mAhg−1 at a current density of 2000mAg−1 in the potential window of 0.2-3.0V, much higher than that of pristine Li4Ti5O12 (141.0mAhg−1). A fairly good cycling stability was also achieved with a capacity retention ratio of 90.0% after working at 1000mAg−1 between 0.2 and 3.0V for 200 times for the V-LTO (1:8) electrode, which is much higher compared with the capacity retention ratio of 73% for electrodes prepared with pristine Li4Ti5O12 under the same condition.
Surface chemistry of the separator plays an important role in the performance of the lithium ion battery separator, which not only influence the wettability with the electrolyte, but also the lithium ion migration through the separator. Here we developed a simple method to modify the polypropylene separator with tannic acid (TA) and polyethyleneimine (PEI). A thin and uniform TA/PEI layer was formed onto the surfaces of the separator through a simple assembly process without destroyed the microstructure. The modified PP separator showed excellent wettability, high ambient ionic conductivity (0.95 mS cm−1) and lithium-ion transference number (0.44), indicating that the TA/PEI layer played a role in the lithium ions migration. The possible mechanism of the surface promoting lithium ion migration was discussed in this paper. The battery performances of the modified separator were also conducted. As a result, cells with the TA/PEI-coated PP separator displayed superior cycle stability and rate capability.
A composite consisting of Bi2O3 nanoparticles encapsulated by three-dimensional (3D) porous nitrogen-doped graphene is reported. Due to the 3D porous structure, the composite has large specific surface area of 112 m2 g−1, which can increase the contact area between active material and electrolyte. In addition, the 3D porous conductive framework can not only facilitate the fast electron transport and Li+ diffusion but also enhance the electrical conductivity of the composite. As expected, the composite shows an outstanding rate capability of 273 mAh g−1 at 10000 mA g−1 and a capacity of 417 mAh g−1 over 100 cycles at a current density of 200 mA g−1. Therefore, the composite is a promising candidate as an anode material for high-rate lithium ion batteries.
Energy storage plays a crucial role in ensuring reliable power supply in a renewable microgrid. The supply and demand variability is found in different time scales (i.e., instantaneous, diurnal, and seasonal). The nominal discharge duration of multiple storage options can be matched effectively for variability in all relevant time scales. An optimum mix of storage options is important to design a cost-effective system. This paper proposes a generic sizing methodology using pinch analysis and design space for hybrid energy storage in a PV-based isolated power system. Pinch analysis utilises a time series simulation of the system where generation should always exceed the load. The methodology defines the design space as feasible combinations of short, medium, and long-term storage size and PV array rating for the given loads. These design space curves are approximated by quadratic equations and the correlations are used as constraints to determine the optimal mix of supply and storage that minimise the life cycle cost. Four different practical cases in Indian context —a remote village, telecom tower, welding shop, and a standby system for a lift load – are analysed to illustrate the sizing method. As an example, the optimal size for a PV based microgrid supplying a remote telecom tower with an average load of 72 kWh/day is 40 kWp of PV, 5 m3 of hydrogen storage and 58 kWh of battery. The proposed methodology extends the design space approach to obtain an optimal minimum cost solution.
This paper studies the problem of deploying electric bicycle (e-bike) sharing stations and determining their capacities, i.e. the number of shared e-bikes and charging piles, considering travelers’ responses to the charging demands and different deployment schemes. Given a one-way station-based setting, we propose an e-bike sharing network where the generalized trip cost is measured as the sum of the delay cost at stations and the travel time en-route. To estimate the trip costs, we modeled the pick-up and drop-off e-bikes at each sharing station as two different queues affected by e-bikes’ charging demands, and described the traffic flow of shared e-bike on each route based on Greenshield’s model. Further, the e-bike sharing station deployment problem was then formulated as a bi-level programming model, taking into account the government’s and individual travelers’ profits. The uniqueness of solution was proved. For the purpose of solution approach, this bi-level model was then reformulated into a single-level mixed-integer programming model, and a hybrid particle swarm optimization algorithm was proposed to solve the single-level model. Numerical experiments were presented to demonstrate the validity of the proposed model and solution technique. More importantly, through numerical experiments, further insights for designing an e-bike sharing system were examined and discussed: 1) sharing stations are bottlenecks in the e-bike sharing network, since the charging activities cause travelers large delay costs; 2) a well-designed quick-charging technology and reservation policy could be incorporated into e-bike sharing systems to reduce system costs; 3) the proposed hybrid particle swarm optimization algorithm shows good solution quality and convergence performance.
The emerging and exponential growth of telecommunication networks have developed a variety of smart and powerful devices to handle a wide range of multimedia applications such as Voice over IP (VoIP), video streaming, etc. 3GPP introduced Long Term Evolution (LTE) in release 8 and LTE-Advanced (A) in release 10 to support multimedia traffic as these technologies offers high data rate, high bandwidth, and low latency. It also created new challenges to handle resource allocation and power optimization of User Equipment (UE). The paper explores radio resource allocation and power consumption problem of UE in LTE environment. An intelligent scheduling scheme developed is based on Cooperative Game Theory (CGT) method and AHP-TOPSIS method. It distributes resources in a fair way among a number of applications and UE are prioritized based on certain criteria like delay, throughput history, UE buffer space and channel conditions and preferences. In LTE, Discontinuous Reception (DRX) has been adopted to conserve the battery life of UE. DRX periodically switches off the radio interfaces to conserve the battery life but it may breach Quality of Service (QoS). Therefore, the DRX parameters need to be further optimized to satisfy QoS and minimize power consumption of UE. DRX parameters are dynamically adjusted on the basis of current load and channel condition of the network. Power saving operations are numerically analyzed. Simulation results show that the expert and an intelligent system can distribute resources in a fair way among UE, improves the battery consumption of UE up to 85% and packets transmission delay by 10% as compared to existing scheme for real-time applications.
Ever since wireless sensor networks (WSNs) have emerged, different optimizations have been proposed to overcome their constraints. Furthermore, the proposal of new applications for WSNs have also created new challenges to be addressed. Cross-layer approaches have proven to be the most efficient optimization techniques for these problems, since they are able to take the behavior of the protocols at each layer into consideration. Thus, this survey proposes to identify the key problems of WSNs and gather available cross-layer solutions for them that have been proposed so far, in order to provide insights on the identification of open issues and provide guidelines for future proposals.
The redox properties of polyphenosafranin were investigated at its different oxidation and protonation levels by potential scan voltammetry and electrochemical impedance spectroscopy. The polymer comprised phenosafranin units linked via a secondary amino nitrogen. A two-electron, two-proton process is proposed as its main redox reaction; its reduction yields the corresponding 5-hydro-phenazine form. In an isolated electroactive site, the polymer resembled redox polymers rather than conducting polymers. Low-frequency capacitance versus potential curves showed their maxima near the formal potential. Since the low-frequency capacitance increased linearly with the film thickness, it was identified with the redox capacitance. The width of the Warburg region showed a minimum at the half-reduced state of the polymer. This relationship indicated that electron transport was a key factor controlling the rate of charge transport in the polymer. The potential of the minimum Warburg width shifted to more negative values as the solution pH increased, with the minimum increasing exponentially with the pH. These observations lead to a conclusion that electron transport occurs via a process of sequential electron self-exchange between neighboring redox sites. This electron hopping is accompanied by proton transfer via intermolecular acid/base reactions.
This paper presents comparative review of experimental and thermodynamic assessment of ternary Ag–Sb–Zn system. Isothermal section of the Ag–Sb–Zn system at 300 °C has been calculated by CALPHAD method using thermodynamic parameters from literature. Microstructural analysis of a number of alloys was carried out by scanning electron microscopy and optical microscopy, whereas chemical composition of observed phases was analyzed using energy-dispersive X-ray spectroscopy. Hardness of selected alloys from four vertical sections was determined using Brinell hardness test and additionally by micro Vickers hardness test. Electrical conductivity of a number of alloys in the ternary Ag–Sb–Zn system was experimentally determined. Good overall agreement between experimental and calculated values was obtained.
In this paper the preparation, the morphology, the structure and the electrochemical performance of carbon coated TiO2 produced by using Tyzor®-LA as a precursor have been studied by using SEM, XRD and electrochemical methods. The electrochemical methods included low rate cycling, cycling at C-rate and cycling at different rates. At the same time the physical and electrochemical properties of LiFePO4 were investigated by using the same methods. Lithium-ion batteries were prepared by sandwiching a glass fiber between a TiO2 electrode used as the anode and a LiFePO4 electrode used as the cathode and tested to evaluate cell performance.
Cysteine protease (CP) and Cysteine protease inhibitor (CPI) or cystatin constitute a critical point in programmed cell death (PCD), a basic biological phenomenon which takes place in the plants, when they are exposed to varying biotic and abiotic stresses. In the present study we isolated and cloned cDNAs encoding cysteine protease and cystatin from early blight infected tomato plants. Using computational biology tools the sequence-structure-function relationships for the tomato cystatin and cysteine protease were elucidated. Interaction between the cystatin and cysteine protease of host and pathogen is higher as compared to interaction shown by cystatin and cysteine protease within the host. The interaction energy of (a)tomato cystatin—tomato cysteine protease, (b)tomato cystatin—fungal cysteine protease and (c)tomato cysteine protease—fungal cystatin are −319.33 Kcal/mol, −504.71 Kcal/mol and −373.731 Kcal/mol respectively. Comparative protein sequence analysis with different plant cystatins and cysteine protease were also done with the sequences of cystatin and cysteine protease isolated from tomato. Structures for all the cystatin and cysteine protease were modeled along with their interactions with fungal cystatin and cysteine protease in order to explore the structural variability and its manifestation at the functional level. This helped to relate the already known functions of these proteins with their sequences as well as the predicted structures. This also served to better understand the CP-CPI interaction operational in developing this protein family and its implication in plant defense during fungal pathogenesis in tomato plants.
Nitrogen-doped porous carbon derived from polyaspartic acid is utilized as activated carbon (AC) electrode for supercapacitor. The BET surface area and pore volume of the AC as high as 1071m2 g−1 and 0.61cm3 g−1. The AC electrode in 1M H2SO4 electrolyte delivers high specific capacitance of 177Fg−1 at a high current density of 15Ag−1. Surprisingly, by introducing redox-mediated 0.6g Na2MoO4 into 40ml 1M H2SO4 as a mixture electrolyte, the specific capacitance of the supercapacitor improved 841Fg−1, about 375.1% of specific capacitance in 1M H2SO4 electrolyte. The high energy density 378.5Whkg−1 is also obtained. Furthermore, the AC electrode in the redox active Na2MoO4 electrolyte shows the excellent capacitance retention of 88.2% for over 1000 cycles. These improved performance are owed to the redox reaction between Mo(VI)/Mo(V) and Mo(VI)/Mo(IV) redox couples in the mixed H2SO4 and Na2MoO4 electrolyte at the electrode|electrolyte interface, and the concentration of the Na2MoO4 can also influence the electrochemical performance of the supercapacitor. Based on the overall performance, it is believed that the combination of polyaspartic acid derived nitrogen-doped porous carbon and redox active Na2MoO4 electrolyte is more attractive in the near future for high performance energy-storage devices.
Thermal and structural stabilities of the delithiated positive electrode material LixCo2/3Ni1/6Mn1/6O2were studied by X-ray diffraction, magnetic and thermogravimetric analysis. In the opposite to the classical electrode materials LiNiO2 and LiCoO2, the structural symmetry (S.G. R-3m) of the starting material LiCo2/3Ni1/6Mn1/6O2 is preserved during the electrochemical cycling with a small variation of the unit cell parameters. Squid measurements evidenced that practically no Ni2+ ions were present in the lithium slab even after the lithium extraction process. For the thermal stability, the highly oxidized phase Li0.3Co2/3Ni1/6Mn1/6O2 was tested. This delithiated phase undergoes only 5.16% weight loss after heating up to 600°C. This weight loss has no effect on the structure symmetry as the starting α-NaFeO2 type structure was preserved during the thermal treatment. The obtained results coupled to the excellent electrochemical features of LiCo2/3Ni1/6Mn1/6O2clearly showits ability to compete with the commercialized cathode materials
The rheological properties of electrode slurries used in the manufacturing of lithium-ion batteries affect the manufacturing processes as well as the battery quality, such as electrochemical and durability performance. There is thus an urgent need to develop a physics-based model to describe the rheological properties of these electrode slurries to enable further optimization of battery electrode production. In this paper, we present a microrheological model for estimating the viscosity of electrode slurries that incorporates colloidal forces such as van der Waals and polymeric steric repulsion forces. The model shows good agreement with the experimentally determined viscosities of a graphite-based anode slurry and should be extendable to describe the rheological properties of cathode slurries.
Olivine-structured LiFePO4 has been the focus of research in developing low cost, high performance cathode materials for lithium ion batteries. Various processes have been developed to synthesize LiFePO4 or C/LiFePO4 (carbon coating on LiFePO4), and some of them are being used to mass produce C/LiFePO4 at the commercial or pilot scale. Due to the low intrinsic electronic and ionic conductivities of LiFePO4, the decrease of particle size and the nano-layer of carbon coating on LiFePO4 particle surfaces are necessary to achieve a high electrochemical performance. Significant progress has been made in understanding and controlling phase purity, particle size and carbon coating of the C/LiFePO4 composite material in the past. However, there are still many challenges in achieving a high quality product with high consistency. In this review, we summarize some of the recent progress and advances based on selected reports from peer-reviewed journal publications. Several typical synthesis methods and the effect of carbon coating quality on the properties of C/LiFePO4 composite are reviewed. An insight into the future research and further development of C/LiFePO4 composite is also discussed.
Poly(2,5-di-(2-thienyl)-furan) (PSOS) was synthesized via anodic polymerization of 2,5-di-(2-thienyl)-furan (SOS) in ethanol solution containing 0.2M LiClO4 as supporting electrolyte. The electrochemical and spectroelectrochemical properties were investigated using electroanalytical and UV–vis spectroscopic techniques, respectively. The band gap of the polymer film was found as 2.22eV and the film was successfully switched between black oxidized state and orange neutral state. Fluorescence and electrochemical impedance spectroscopy (EIS) studies were also performed.
A porous Co3O4 nanoflake array film grown on nickel foam is prepared by a hydrothermal synthesis for pseudo-capacitor application. The pseudocapacitive behavior of the Co3O4 nanoflake array is investigated by cyclic voltammograms (CV), galvanostatic charge–discharge tests and electrochemical impedance spectroscopy (EIS) in 2 M KOH at different temperatures. The specific capacity is 210, 289 and 351 F g−1 at 2 A g−1 tested at −5 °C, 25 °C and 60 °C, respectively, corresponding to that of 184, 243 and 242 F g−1 at 20 A g−1. After 4000 cycles at 2 A g−1, the remaining specific capacity is 187, 342 and 124 F g−1 tested at −5 °C, 25 °C and 60 °C. It shows that with increasing the temperature from −5 °C to 60 °C, the specific capacity increases, while the cycling stability becomes worse. The operation temperature has a pronounced influence on the pseudocapacitive performance of Co3O4 nanoflake array.
A controversial issue in the cognitive neuroscience of language is the question whether independent lexical representations need to be included in cognitive models. Recent models claim to account for the available data without including phonological or orthographic lexicons. These models base their lexical decision (“Is it a word or not?”) either on familiarity of the input string or alternatively, on semantic information. These two alternatives were evaluated in a series of experiments with an individual suffering from word-meaning deafness. This is a rare disorder of auditory word comprehension which affects mapping of a word’s phonology to its meaning. The participant, BB, was unaffected by the ‘word-likeness’ of nonwords with comparable accuracy for plausible and abstruse nonwords. She was further able to make lexical decisions despite her severe impairment in comprehending the word’s meaning. Lexical and semantic processing were assessed on an item-specific basis providing a methodological advancement over previous studies. The comprehension tasks involved word-picture matching as well as definition tasks. The results suggest that BB’s lexical decisions are based neither on familiarity of the input string nor on semantic information, which was largely unavailable. The only alternative are lexical representations on which she could base her decisions.