batterydata/paper-abstracts huggingface dataset:
Well-defined LiNi0.5Mn1.5O4 powder has been synthesized by ethylene glycol (EG)-assisted oxalic acid co-precipitation method. The structure and physicochemical properties of this as-prepared powder were investigated by powder X-ray diffraction (XRD), Raman spectra (RS), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge test in detail. XRD shows impurity phase of LiyNi1-yO due to the oxygen loss reaction at high temperatures. SEM indicates that LiNi0.5Mn1.5O4 synthesized by EG-assisted method has a uniform and narrow size distribution under 1μm. RS confirms that both samples have Fd-3m space group. EIS and CV test exhibit that LiNi0.5Mn1.5O4 electrode synthesized by EG-assisted method has lower potential polarization, smaller charge transfer resistance, higher reversibility and larger lithium ion diffusion coefficient than the one obtained by ammonium hydroxide co-precipitation method. Galvanostatic charge–discharge test reveals that LiNi0.5Mn1.5O4 synthesized by EG-assisted method shows higher discharge capacity than that the one synthesized by ammonium hydroxide co-precipitation method at each rate.
In this paper we report a solid state lithium ion battery based on nanostructured titanium oxide (TiO2) anode, olivine lithium iron phosphate (LiFePO4) cathode and polyethylene oxide (PEO)-based electrolyte. The battery evidences average working voltage of 1.8 V and specific capacity of 150 mA h g−1. The solid cell configuration is characterized by enhanced electrochemical properties, high safety level and remarkable environmental compatibility. The preliminary results here reported suggest that the system may be suitable to be used as alternative energy storage system for powering safe and environmental friendly hybrid and electric vehicles.
In areas where grid connection is difficult and costly, the use of renewable energy is both economically and environmentally advantageous. Due to typically low system efficiency (∼10%) and intermittency of photovoltaic (PV) electricity generation, a new design of multi-level H-bridge inverter technology is considered. This multi-level technology increases DC to AC conversion efficiency and the design includes battery energy storage to enable 24/7 operation. The proposed multi-level inverter is compared and contrasted with other existing designs. The proposed cascaded inverter provides lower switching losses, simple switching techniques, modularity, and simpler charge-balancing approaches than conventional technology. A switching technique was designed for the proposed multi-level inverter to ensure balancing of state of charge of each battery. The effectiveness of the switching was demonstrated via simulations. The simulations also show that the total harmonic voltage distortion of the proposed inverter is less than 6% without any filtering requirements.
K2S and FeS were employed as additives for electrolyte and electrode, respectively, to suppress hydrogen evolution and improve the cycleability of the Fe/C composite air battery anode. The effects of these additives on the electrochemical properties of Fe/C composite electrodes were investigated using cyclic voltammetry (CV). The results showed that both K2S and FeS significantly suppressed hydrogen evolution on the Fe/C electrode characteristics. Among the carbons used, nano-carbons such as tubular carbon nanofibers (CNF), platelet CNF, vapor-grown carbon fibers (VGCF) and acetylene black (AB) improved the discharge capacity of the Fe/C electrode with additive to electrolyte or electrode. The FeS additive showed a larger beneficial effect for the Fe/C composite electrode than K2S in term of cycleability and capacity.
This paper presents a scaling methodology based on dimensional analysis and applicable to systems’ mathematical models. The main goal of this research is to propose time-accelerated and size-scaled HIL (Hardware In the Loop) experiments, while keeping similarity with respect to the dynamics of the original system. The scaling process is presented using a simple wind turbine model. The scaling method is validated through simulations in which a wind turbine model and an electrochemical battery model are connected together. Finally, an experimental real-time validation is performed using physical emulators.
C-LiFePO4 and C-Li4Ti5O12 electrodes were studied for their electrochemical performance at sub-zero temperatures with two different electrolytes, conventional and low temperature electrolytes. 18,650-size cylindrical cell using the conventional electrolyte 1 mol L−1 LiPF6 in EC + DEC displayed a discharge capacity of 1.01 Ah, when cycled between 1.0 and 2.8 V, during low 0.1 C charge-discharge rates at 25 °C with 98%. Same cell with LiPF6 in EC/DEC electrolyte showed a discharge capacity of 0.97 Ah at 10 °C during low 0.1 C charge-discharge rates and retained more than 75% of rated capacity at 5 C-rate. However, the cell failed at 8 C-rate due to poor ionic conductivity of the electrolyte. The 18,650 cell using the low temperature electrolyte 1 mol L−1 LiPF6 and 0.2 mol L−1 LiFSI in quaternary blend of aliphatic solvents such as PC + MP + EMC + 5% FEC displayed a similar electrochemical performance at 25 °C as that of the cell with conventional electrolyte, but in contrast showed improved electrochemical performance down to −10 °C due to improvement in ionic conductivity of the electrolyte. HPPC test performed on the C-LiFePO4//C-Li4Ti5O12 18,650 cell with low temperature electrolyte indicated the cells remain functional between 0 °C and −10 °C.
Lithium metal free sulfur battery paired by lithium sulfide (Li2S) is a hot point in recent years because of its potential for relatively high capacity and its safety advantage. Due to the insulating nature and high sensitivity to moisture of Li2S, it calls for new way to introduce Li ion into S cathode besides the method of directly using the Li2S powder for the battery pre-lithiation. Herein, we proposed a pre-lithiation method to lithiate the polypyrrole (PPy)/S/Ketjenblack (KB) electrode into PPy/Li2S/KB cathode at room temperature. By this process, the fully lithiated PPy/Li2S/KB cathode showed facilitated charge transfer than the original PPy/S/KB cathode, leading to better cycling performance at high C-rates and disappearance of over potential phenomenon. In this work, the ion-selective PPy layer has been introduced on the cathode surface by an electrodeposition method, which can suppress the polysulfide dissolution from the cathode source. The lithium metal free full battery coupled by the prepared Li2S/KB cathode and graphite anode exhibited excellent cycling performance. Hence, we believe this comprehensive fabrication approach of Li2S cathode will pave a way for the application of new type lithium metal free secondary battery.
Verb inflection errors, often seen in agrammatic aphasic speech, have been attributed to either impaired encoding of diacritical features that specify tense and aspect, or to impaired affixation during phonological encoding. In this study we examined the effect of semantic markedness, word form frequency and affix frequency, as well as accuracy and error patterns, in an attempt to evaluate whether diacritical or affixation operations are impaired. Verb inflections (V+ing, V+ed, V+s, and V stem in present progressive, past, present 3rd person singular, and future tense contexts, respectively) were elicited in eight mild-moderate agrammatic aphasic individuals in a sentence context using a picture description task. Results revealed that the majority of verbs produced were affixed (75%) although accuracy was low (36%). Word form frequency was found to be a significant predictor of the accuracy with which verb inflections were produced; while affix frequency and semantic markedness were not found to influence accuracy. These results suggest that a diacritical deficit is more likely to undermine the production of verb inflections than a affixation deficit, and indicate that when diacritical processes are compromised, word form frequency is likely to influence production of verb inflections in agrammatic aphasia.
Simulated Annealing and Genetic Algorithms are important methods to solve discrete optimization problems and are often used to find approximate solutions for diverse NP-complete problems. They depend on randomness to change their current configuration and transition to a new state. In Simulated Annealing, the random choice influences the construction of the new state as well as the acceptance of that new state. In Genetic Algorithms, selection, mutation and crossover depend on random choices. We experimentally investigate the robustness of the two generic search heuristics when using pseudorandom numbers of limited quality. To this end, we conducted experiments with linear congruential generators of various period lengths, a Mersenne Twister with artificially reduced period lengths as well as quasi-random numbers as the source of randomness. Both heuristics were used to solve several instances of the Traveling Salesman Problem in order to compare optimization results. Our experiments show that both Simulated Annealing and the Genetic Algorithm produce inferior solutions when using random numbers with small period lengths or quasi-random numbers of inappropriate dimension. The influence on Simulated Annealing, however, is more severe than on Genetic Algorithms. Interestingly, we found that when using diverse quasi-random sequences, the Genetic Algorithm outperforms its own results using quantum random numbers.
Battery electric vehicles (BEVs) offer the potential to reduce both oil imports and greenhouse gas emissions, but have a limited utility due to factors including driver range anxiety and access to charging infrastructure. In this paper we apply NREL's Battery Lifetime Analysis and Simulation Tool for Vehicles (BLAST-V) to examine the sensitivity of BEV utility to range anxiety and different charging infrastructure scenarios, including variable time schedules, power levels, and locations (home, work, and public installations). We find that the effects of range anxiety can be significant, but are reduced with access to additional charging infrastructure. We also find that (1) increasing home charging power above that provided by a common 15 A, 120 V circuit offers little added utility, (2) workplace charging offers significant utility benefits to select high mileage commuters, and (3) broadly available public charging can bring many lower mileage drivers to near-100% utility while strongly increasing the achieved miles of high mileage drivers.
Integrating physical objects with the corresponding enterprise applications any time any where is the essential issue for a real-time enterprise. This study proposes a multi-agent system framework called agent-based manufacturing control and coordination (AMCC) system, a agent-based framework using ontology and RFID technology to monitor and control dynamic production flows and also to improve the traceability and visibility of mass customization manufacturing processes. The capabilities offered by multi-agent systems to respond to RFID events in real-time and a broad class of agent design and coordination issue regarding just in time (JIT) and just in sequence (JIS) manufacturing processes are also exploited in this study. To validate the proposed framework, case study of a bicycle manufacturing company is used to demonstrate how the proposed framework can benefit its JIT production. Finally, an example prototype system is implemented to demonstrate the concept of the proposed framework.
MgO-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 was synthesized via melting impregnation method followed by a solid state reaction. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) show that the MgO layer is well coated on the surface of the layered oxide particles. Although the initial discharge capacity of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 with proper MgO modification decreases compared to the bare one, the 2wt.% MgO coated cathode exhibits the excellent cycling stability with capacity retention of 96.4% at a current density of 200mAg−1 after 100 cycles at room temperature and 94.3% after 50 cycles at 60°C. Electrochemical impedance spectroscopy (EIS) shows that the thin MgO layer mainly reduces the charge transfer resistance and stabilizes the surface structure of active material during cycling. Melting impregnation method is promising for MgO coating to improving the cycling stability of Li-rich layered oxide cathode for Li-ion batteries.
Photovoltaic (PV) systems are increasingly deployed on buildings in urban areas, causing additional power flows and frequency fluctuation on the low voltage electricity grid. Control strategies for PV-battery energy storage systems (BESS) assist in reducing power flows to the grid and improve the self-consumption of PV generated electricity. Therefore, these control strategies require accurate forecasts of PV electricity production and electricity consumption. We developed and assessed relatively simple forecasting methods using 5 min resolution data, to predict the PV yield and to forecast electricity consumption for one year. We used these forecasts with a predictive control strategy to increase PV self-consumption, decrease curtailment losses and improve BESS revenues. Electricity demand patterns of 48 residential and 42 commercial Dutch buildings were used. PV yield forecast methods that uses predicted weather data shows the lowest forecast error. The best performing forecast method for predicting energy consumption of residential buildings requires historical energy consumption data of the previous seven days. Commercial systems require historical energy consumption of the previous weekday. Significant reduction in curtailment losses is achieved using predictive control strategies, especially in combination when clear-sky radiation data is used to forecast PV yield. Similar self-consumption rates were found for predictive control as for real-time control. This indicates that reduction of curtailment loss can be combined while maintaining the level of PV self-consumption. Revenues from battery storage are increased by forecast methods and are highly dependable on boundary condition of a PV-battery system, such as the feed-in limit (FIL) and the feed-in tariff. Therefore, we recommend customizing battery control strategies based on these system boundaries conditions to improve energy storage potential.
In the last decade a high amount of photovoltaic and wind power generators have been connected to the electric grid, introducing operational problems for transmission and distribution system operators due to the variability and the non-programmability of solar radiation and wind. The paper concerns an analysis on the benefits in adopting storage systems to reduce the imbalance costs associated to renewable energy sources. An analysis on a photovoltaic system has been performed considering different battery technologies. Discrete-time Markov chains have been used to generate a 20 years' time series of irradiance, that has been used to calculate the PV power production. Markov simulation parameters have been deeply studied in order to optimize them and obtain reliable synthetic data of ground irradiance. This data was then used as input of a hybrid PV and storage model allowing to obtain realistic economic and technical results, improving thus the results respect to the methods based on probabilistic weather simulations. An imbalance tariff has been assumed and its cost has been analysed in relation to the storage system costs. An optimal size for the different battery technology has been investigated considering the reduction of variability of the photovoltaic production and the economic convenience of the hybrid system. The use of Markov chains for the optimization of the battery size can be considered as the major novelty of the proposed approach.
In this work, novel methods based on gas chromatography (GC) for the investigation of common organic carbonate-based electrolyte systems are presented, which are used in lithium ion batteries. The methods were developed for flame ionization detection (FID), mass spectrometric detection (MS). Further, headspace (HS) sampling for the investigation of solid samples like electrodes is reported. Limits of detection are reported for FID. Finally, the developed methods were applied to the electrolyte system of commercially available lithium ion batteries as well as on in-house assembled cells.
Objective In order to compare the cognitive functions in children with newly diagnosed temporal (TLE) versus frontal lobe epilepsy (FLE) and control group which consisted of healthy children the following prospective study was performed. Material and methods 39 children with TLE 24 children with FLE and 24 healthy subject were included in study. Each child had neuropsychology assessment using age-normed and validated instruments. The applied test battery consisted of measures assessing both intelligence as well as executive and motor skills. The children were reassessed one and two years. Results In all epilepsy patients there was no evidence of anatomical brain damage. There were no differences in mean age and gender between the groups. There was no significant difference in global IQ scores between the groups. Children with FLE had significantly lower scores than the other two groups in non-verbal memory tasks, presented higher attention deficit and had slower performance speed. The TLE group performed significantly worse as compared with control group in verbal learning and performance speed with no differences in attention. The correlations between the results of test and the localization of epileptic foci were performed. In long term outcome the “frontal” group performed significantly worse than other groups. detailed analysis of cognitive impairment was performed. Conclusion The children with new onset FLE present with more severe cognitive and attention problems in course of disease compared with TLE group, however the TLE group differ significantly in some measures with control group.
Few studies have assessed pre-surgery cognitive impairment or the impact of pre-surgery cognitive impairment on quality of life. The purpose of this study was to assess changes in perceived cognitive function from pre-surgery to 1 month post-surgery and to determine whether cognitive function predicted health-related quality of life in women who awaited adjuvant treatment for breast cancer.
NiFe2O4 (NFO) with different morphologies were successfully synthesized via a facile hydrothermal method of different precipitants. Results showed that the NFO obtained using urea as precipitant (NFO-U) formed a nanosheet shape, while the powders prepared using CH3COONa (NFO-C) exhibited a nanoparticle structure. Both of the two NFO showed a good crystallinity. Conclusion was reached through the results of BET and electrochemical tests that layer structure would improve the properties through a larger specific surface area. Encouragingly, the specific capacitance of NFO-U could arrive 240.9 F/g at the current density of 1 A/g. It was worth noting that the cycle performance of NFO-U was excellent, of which the specific capacitance improved to 128% after 2000 cycles. In addition, an asymmetric supercapacitor (ASC) system was constructed utilizing NFO-U as positive electrode while activated carbon (AC) as negative electrode. The two-electrode system showed a good performance with energy density of 10.15 Wh/kg at a power density of 140 W/kg. Therefore, the construction of sheet-like structures greatly improved the electrochemical performance of NiFe2O4 materials.
The effect of resuspension on sediment–water solute exchange was studied in the archipelago outside the city of Göteborg (Sweden) during the winter months 2001/2002 by a combination of benthic flux (employing both in situ and laboratory incubations), meteorological and hydrodynamic measurements. Resuspension was created in in situ incubation chambers to study the possible resuspension effect on the fluxes of nutrients, oxygen and total carbonate. In most cases, resuspension changed the flux rates. The fluxes of oxygen, total carbonate and phosphate decreased during the resuspension event. The oxygen fluxes before resuspension were between 15 and 23 mmol m−2 day−1 in the four chambers, and decreased during resuspension to between 8 and 18 mmol m−2 day−1. The fluxes of total carbonate in the chambers before resuspension were 12–35 mmol m−2 day−1 and decreased to 4–15 mmol m−2 day−1. The change for each flux during resuspension was statistically significant. The fluxes of nitrate–nitrite and silicic acid increased, whereas the fluxes of ammonium did not change significantly. Hydrodynamic and meteorological data showed that the natural created resuspension at the study site were not due to wind-induced waves, but to strong bottom currents that can be caused when water built-up against land during strong wind events. When the wind abates, the water is flushing back and creates strong currents high enough to cause resuspension of the bottom sediments. A major storm passing the area during the experimental period caused particulate material to suspend to a concentration of about 11 mg/l in the bottom water, which was similar to the suspended material concentration in one set of the incubation chambers.
Variation in energy capacity and resistance of cells connected in parallel can degrade the overall performance of the energy storage system (ESS). Such variations can lead to significant individual differences in battery load current, state of charge (SOC) and heat generation. An experimentally validated 1D electrochemical-thermal model of a large format 53 Ah pouch cell is employed to underpin the performance evaluation of parallel connected cells within the context of a complete ESS. The cell model, developed within COMSOL Multiphysics is coupled with an electrical circuit model of the ESS within Matlab. Results are presented that quantify cell-to-cell differences in load current and heat generation as the length of the parallel connection and value of the cell interconnection resistance is varied. The results highlight that variations in cell depth of discharge and the occurrence of temperature gradients across the parallel connection increases at higher load currents and interconnect resistances. The impact is amplified as the length of the parallel connection increases which will accelerate cell ageing and, if unmanaged, may present safety concerns.
Publisher Summary Flammable gases and volatile liquids are hazardous because of the relative ease with which they produce mixtures with air within the flammable range. An increase in the surface area of any liquid facilitates vaporization. For each substance, there is a minimum concentration of gas or vapor below which flame propagation will not occur (that is, the mixture is too lean). There is also a concentration above which the mixture is too rich to ignite. The limits of flammability are influenced by temperature and pressure (for example, the flammable range expands with increased temperature). Generally, the wider the flammable range, the greater the fire risk.