batterydata/paper-abstracts huggingface dataset:
Physics-based battery models can be very complex and require careful experimental validation, but yield greater insights into the internal processes and their interactions than other cell modelling approaches. The complexity is associated with the large number of input parameters that (a) have varying degrees of identifiability, (b) can be constant or varying, and (c) appear in complex combinations with the model variables and each other. The current work studies this complexity by proposing a unique stepwise approach and purposefully addresses the computational cost associated with estimating these parameters. An initial set of 50 input parameters is reduced to only 8 highly influential parameters that can be subjected to parameter optimization. Elementary effects analysis using the Morris method is applied and demonstrates that the electrode kinetic parameters dominate the cell’s voltage response as simulated by the model. These influential parameters are subjected to variance-based sensitivity analysis using Monte Carlo experiments and Jansen’s formulae for variance decomposition. The first-order and total sensitivities during various modes of operation indicate that the charge transfer coefficients and effective exchange current densities have the most influence on the model error and should be subjected to further optimization. The model error’s sensitivity also reveals high parameter identifiability within subsets of the experimental data and indicates that some parameter values might be valid for longer timescales rather than shorter timescales. The proposed stepwise approach can be applied to any complex physics-based cell model regardless of the cell’s chemistry, format or form factor.
Carbon powder has been predominately used to form cathode electrodes for non-aqueous lithium-air batteries, mainly due to their large specific surface area. An issue, however, with carbon-powder based cathodes is the large oxygen transport resistance due to limited pore spaces resulting from the packing with nanosized spherical particles, leading to a practical discharge capacity much lower than the theoretical value. The present work addresses this issue by proposing a composite cathode made of carbon powder and nanotubes for non-aqueous lithium-air batteries. The discharge performance characterizations show that the discharge capacity of the cathode with mixed carbon materials increases with an increase in the ratio of carbon nanotubes to powder. At the ratio of 1:1, the highest volumetric and the gravimetric capacity are achieved, which are respectively 67.2% and 36.3% higher than those with the cathode made of pure carbon powder. It is further demonstrated that the battery with the composite cathode at a fixed capacity of 1.0mAh/cm2 exhibits a cycle life of up to 50 cycles, which is nearly twice the cycle number of the battery with its cathode made of pure carbon powder. The mechanism leading to the improved performance can be mainly attributed to the improved oxygen transport as the result of enlarged pore spaces with an appropriate composition of spherical carbon powder and cylindrical carbon nanotubes.
The effect of 2-butyne-1, 4-diol (BD) on the deposition behavior of the Co-Ni alloy was investigated by linear sweep voltammetry. The results showed that BD could prevent the deposition of the Co-Ni alloy. The effect of BD concentration in the sulfate plating bath, on the structure of the Co-Ni deposit was studied by energy dispersive x-ray spectroscopy, scanning electron microscope, and X-ray diffraction, respectively. As a result, BD could smoothen the deposit surface and decrease the diameter of the grain, but too much of BD was not good for the size of the grain. In general, a hexagonal close-packed (hep) phase of the Co-Ni alloy, with a preferentially oriented (110) plane, was prepared by electrodeposition in the presence of BD. The Co-Ni alloy as a catalyst for the electro-oxidation of ethanol in alkaline medium was investigated by cyclic voltammetry. The deposit plated from the bath containing BD possessed better electro-oxidation of ethanol performance compared with that of the deposit plated from only the sulfate plating bath, but too much of BD was not beneficial for catalytic activity. The Co-Ni film was suitable as a magnetic recording material.
Lithium-ion batteries are commonly used in hybrid electric and full electric vehicles (HEV and EV). In HEV, thermal management is a strict requirement to control the batteries temperature within an optimal range in order to enhance performance, safety, reduce cost, and prolong the batteries lifetime. The optimum design of a thermal management system depends on the thermo-electrochemical behavior of the batteries, operating conditions, and weight and volume constraints. The aim of this study is to investigate the effects of various operating and design parameters on the thermal performance of a battery module consisted of six building block cells. An electrochemical-thermal model coupled to conjugate heat transfer and fluid dynamics simulations is used to assess the effectiveness of two indirect liquid thermal management approaches under the FUDC driving cycle. In this study, a novel pseudo 3D electrochemical-thermal model of the battery is used. It is found that the cooling plate thickness has a significant effect on the maximum and gradient of temperature in the module. Increasing the Reynolds number decreases the average temperature but at the expense of temperature uniformity. The results show that double channel cooling system has a lower maximum temperature and more uniform temperature distribution compared to a single channel cooling system.
Reduced graphene oxide was firstly introduced to synthesize MnO/rGO nanocomposite by a facile pyrolysis method. MnO nanoparticles with an average size of about 30nm were uniformly decorated on the rGO matrix. Note that the mass content of rGO in the composite is only ∼6%. The MnO/rGO composite exhibited superior rate capability and improved cycling stability due to the high conductivity and two dimension (2D) structure of the reduced graphene oxide. It could deliver reversible capacities of 952.2, 727.9, 608.7 and 422.4 mAh g−1 at current densities of 0.1 A g−1, 1 A g−1, 2 A g−1 and 5 A g−1, respectively and without obvious capacity fading during 150 cycles at the current density of 0.5 A g−1.
Two types of fuel cell systems using NaBH4 aqueous solution as a fuel are possible: the hydrogen/air proton exchange membrane fuel cell (PEMFC) which uses onsite H2 generated via the NaBH4 hydrolysis reaction (B-PEMFC) at the anode and the direct borohydride fuel cell (DBFC) system which directly uses NaBH4 aqueous solution at the anode and air at the cathode. Recently, research on these two types of fuel cells has begun to attract interest due to the various benefits of this liquid fuel for fuel cell systems for portable applications. It might therefore be relevant at this stage to evaluate the relative competitiveness of the two fuel cells. Considering their current technologies and the high price of NaBH4, this paper evaluated and analyzed the factors influencing the relative favorability of each type of fuel cell. Their relative competitiveness was strongly dependent on the extent of the NaBH4 crossover. When considering the crossover in DBFC systems, the total costs of the B-PEMFC system were the most competitive among the fuel cell systems. On the other hand, if the crossover problem were to be completely overcome, the total cost of the DBFC system generating six electrons (6e-DBFC) would be very similar to that of the B-PEMFC system. The DBFC system generating eight electrons (8e-DBFC) became even more competitive if the problem of crossover can be overcome. However, in this case, the volume of NaBH4 aqueous solution consumed by the DBFC was larger than that consumed by the B-PEMFC.
FePO4 nanoparticles, acted directly as cathode materials in lithium ion rechargeable batteries, were synthesized by a microemulsion technique. The various grain-sized and crystal-structured FePO4 samples were obtained by sintering at different temperatures (380°C, 460°C, 550°C, 650°C) for 3h in air. The structure and morphology were investigated by means of X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM); the electrochemical properties were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge and discharge tests. Results show that FePO4 sintered at 380°C and 460°C for 3h are amorphous, and with fine sizes in the range of 10–20nm. Increasing the sintering temperature leads to an increase in grain size and makes the structure change from amorphous to trigonal. The EIS results show that the R ct value of FePO4 sintered at 460°C is smaller than that sintered at 650°C. The diffusion coefficients of lithium ion (D Li) of FePO4 sintered at 380°C, 460°C, 550°C and 650°C measured by EIS are 8.09×10−14, 1.06×10−13, 4.88×10−14 and 2.59×10−14 cm2 s−1, respectively. The difference in diffusivity is also confirmed by CV and the D Li values are 6.71×10−14, 8.28×10−14, 4.89×10−14 and 1.60×10−14 cm2 s−1, respectively. The correlations between the electrochemical performances of FePO4 and lithium ion diffusion are acquired. The charge and discharge tests show that the initial discharge specific capacity of FePO4 sintered at 460°C for 3h reaches 142.3mAhg−1 at 0.1°C. These results suggest that nanoparticles and amorphous FePO4 facilitates lithium ion diffusion during the charge/discharge cycles.
The future power system is characterized by more renewable and uncontrollable capacity at the supply side and an electrification of energy at the demand side. Both evolutions increase the need for flexibility in the power system. Although this flexibility can be triggered at the supply and demand side, the latter is often overlooked. In this perspective, this paper assesses the impact of the use of flexibility at the demand side, also referred to as demand response, on power system operation. A two-stage modeling approach is used which combines a day-ahead deterministic unit commitment model and an hourly simulation in real-time. This approach is tested for two alternative Belgian generation technology mix scenarios including a detailed representation of residential demand response. Hereby, realistic cycling patterns of white goods and mobility patterns of battery electric vehicles serve as an input. This approach allows to quantify operational benefits of demand response and to assess a potential introduction of demand response in power system operation. Results show that in general demand response contributes to a lower cost, higher reliability, and lower emission level of power system operation. Moreover, a higher amount of uncontrollable capacity increases these benefits and therefore the societal value of demand response.
Neurotoxic effects are a non-cancer endpoint for health risk, and neurobehavioral screening tests can serve as a first tier investigation of neurotoxicity [US EPA, Federal Register 63 (1998) 26926]. Analysis of neurobehavioral screening data such as those of the functional observational battery (FOB) traditionally relies on analysis of variance (ANOVA). ANOVA is designed to detect whether there are dose-effects, but does not model the underlying dose–response relationship and subsequent risk assessment fails to utilize the shape of the underlying dose–response. In contrast, dose–response modeling interpolates toxic effects between experimental points, and permits prediction of toxic effects within the experimental range. Additionally it is also a prerequisite for estimating a benchmark dose. This paper discusses dose–time–response modeling of longitudinal neurotoxicity data and illustrates the methods using three continuous FOB outcomes from an EPA study involving acute exposure to triethyltin (TET). Several mathematical functions are presented as candidate dose–time–response models. The use of random effects is discussed to characterize inter-subject variation. The results indicate that it is feasible to use simple mathematical functions to model empirical dose–time–response observed in existing longitudinal neurotoxicological data. Further research is needed on the types of design and data required to reliably approximate the true underlying dose–time–response.
Competence with fractions predicts later mathematics achievement, but the codevelopmental pattern between fractions knowledge and mathematics achievement is not well understood. We assessed this codevelopment through examination of the cross-lagged relation between a measure of conceptual knowledge of fractions and mathematics achievement in sixth and seventh grades (N =212). The cross-lagged effects indicated that performance on the sixth grade fractions concepts measure predicted 1-year gains in mathematics achievement (ß =.14, p <.01), controlling for the central executive component of working memory and intelligence, but sixth grade mathematics achievement did not predict gains on the fractions concepts measure (ß =.03, p >.50). In a follow-up assessment, we demonstrated that measures of fluency with computational fractions significantly predicted seventh grade mathematics achievement above and beyond the influence of fluency in computational whole number arithmetic, performance on number fluency and number line tasks, central executive span, and intelligence. Results provide empirical support for the hypothesis that competence with fractions underlies, in part, subsequent gains in mathematics achievement.
Lithium metal is known as a very promising anode material for lithium-based batteries possessing a quite high theoretical capacity. But it has been kept away from practical applications due to its extreme reactivity and potential safety hazards led by serious dendrite growth. The origins of dendrite formation may be associated with the mechanisms of Li plating and with the mode of charge transfer during Li reduction or oxidation at the anode-electrolyte interface. Here, density functional theory (DFT) calculations are conducted to analyze the electron transfer between Li (100) and Li cations located in the proximity of the surface in several simulation models. The study includes two common used solvents: ethylene carbonate and dimethoxyethane (EC and DME), and a LiPF6 salt, that surround the Li cation over perfect, defect-containing, and Li2CO3-passivated Li (100) surfaces. Our calculations demonstrate that the Li cation is easily reduced when bonding to DME rather than EC and its preferred deposition site is the hollow site on both perfect and defective Li (100). Additionally, a compact Li2CO3 layer inhibits the charge transfer from Li metal to Li cations, thus modifying Li plating. It is concluded that the extreme reactivity of the Li metal surface induces a strongly inhomogeneous electron distribution upon deposition of a cation on the surface. This strong charge inhomogeneity may promote uneven Li nucleation and growth, eventually resulting in dendritic behavior.
Energy is one of the essential inputs for economic development and industrialization. A reliable supply of energy is essential to maintain and to improve human being’s living conditions. The management of energy sources, rational utilization of energy, and renewable energy source usages are vital. Among the renewable energy sources wind energy is currently viewed as one of the most significant, fastest growing, and commercially attractive source to generate electrical energy because of the mature and cost effective energy conversation technology. Developing a utility-scale wind project is a complicated and time-consuming process which involves developers, landowners, utilities, the public and various local authorities. This article discusses the past, the present and the future of wind energy use in Pakistan. The efforts for the utilization of wind energy in the country are presented as well, along with barriers in its development. It is concluded that the potential exists, but significant efforts are needed to effectively make use of this cheap renewable energy source.
Al-substituted α-type nickel hydroxides (α-Ni(OH)2) containing different interlayer anions ( NO 3 − , SO 4 2 − , Cl−, CO 3 2 − , OH−) are synthesized via a polyacrylamide (PAM) assisted two-step drying method. The effects of interlayer anions on the microstructure, morphology and electrochemical performance of Al-substituted α-Ni(OH)2 are investigated by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. The results demonstrate that the intercalated anions have a critical effect on the basal plane spacing, degree of crystallinity, and electrochemical properties of the end products. Especially, the intercalated anions have a marked impact on the activation process of the nickel electrodes. The Cl− intercalated α-Ni(OH)2 sample exhibits better high-rate discharge ability and cycle stability than samples with other interlayer anions. This is attributed to the higher crystallinity, better exchange ability and smaller anion size of Cl−. The anion exchange ability and the size of anions also play an important role in the proton diffusion rate, which directly affects the electrochemical properties of α-Ni(OH)2. The relationships between the specific capacity and basal spacing are also discussed in details for the five samples.
Executive functions (EF) are generally described as showing greater sensitivity to ageing compared to other cognitive domains. Numerous pitfalls exist in the measurement of EF due to loose definitions and lack of agreement on these concepts and uncertainty about the constructs being measured. To this date, the validity of EF constructs has not been examined in the old-old population. Performance of 122 randomly selected community dwellers aged between 81 and 97 years on nine EF tasks (seven of which commonly used in clinical practice) was examined. Factor analytic procedures using structural equation modelling (SEM) failed to satisfactorily explain the data according to four a priori models, the first two models reflecting two major constructs commonly found in current models of EF (“set” and “switch”), the last two reflecting task requirements. The best measure for each task was extracted using statistically driven analyses and further SEM revealed an orthogonal two-factor model which provided a good fit of the data, explaining between 8% and 25% of the total variance. This model can be interpreted in terms of reactive and spontaneous flexibility as proposed by Eslinger and Grattan (1993), with the first factor reflecting internally driven strategies and the second environment dependent strategies. Furthermore, these findings also suggest that: (a) unique tasks of EF may not be applicable to all age groups due to individual experience and changes in strategies; and (b) current clinical instruments may be inadequate to measure very specific aspects of the complex construct of EF.
Highly fluorinated graphite was prepared at room temperature using high oxidation state transition metal complex fluoride (K2PdF6, K2MnF6, K2NiF6 or KAgF4) and elemental fluorine under pressure ((5.9–11.8) ×105 Pa) in anhydrous liquid HF (aHF). The composition of the fluorinated graphite samples ranged from C1.1F to C1.9F containing small amounts of HF. IR absorption spectra revealed that stage 1 phase of C x F contained several different phases with planar (sp2) and puckered (sp3) graphene layers. Electrochemical discharge of the fluorinated graphite showed that profile of discharge potential and discharge capacity varied depending on the amount of cointercalated HF. The C x F samples with less amounts of HF and HF2 δ− had relatively flat discharge potentials and large discharge capacities. The discharge capacity reached 500–600mAh/g in 1mol/dm3 LiClO4–propylene carbonate solution at 25°C. Chemical diffusion coefficients of Li+ ion in the intermediate discharge products were (4.4–13) ×10−12 cm2/s from impedance measurement.
Electrification is seen as the future of automotive industry, and deployment of electric vehicles largely depends on the development of rechargeable batteries. Here, the authors survey the state-of-the-art advances in active materials, electrolytes and cell chemistries for automotive batteries.
An environmental-friendly and low-cost polymer, polytetrafluoroethylene (PTFE) has been applied as an aqueous-based binder for the fabrication of LiFePO4/C electrode. The electrode with PTFE has been compared to the electrode with the conventional binder, polyvinylidene fluoride (PVDF) via Rheology test, X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and electrochemical tests. The Rheology test indicates that the viscosity of the slurry prepared with PTFE as a binder is better than that prepared with PVDF. The electrochemical measurements demonstrate that the electrode with PTFE binder displays a higher discharge capacity of 161.1 mAh g−1 compared to the electrode with PVDF binder, which shows a discharge capacity of 150.7 mAh g−1. The EIS analysis indicates the LiFePO4/C electrode with PTFE binder shows a higher ionic conductivity and a smaller increasing in charge transfer rate compared to the LiFePO4/C electrode with PVDF binder. In addition, the electrodes applying the aqueous-based binder have been optimized by controlling the moisture content in the electrodes. The electrochemical enhancement of these electrodes can be achieved by controlling the vacuum drying temperature and time during the preparation of the electrodes.
Today’s lithium (Li)-ion batteries have been widely adopted as the power of choice for small electronic devices through to large power systems such as hybrid electric vehicles (HEVs) or electric vehicles (EVs). However, it falls short of meeting the demands of new markets in these areas of EVs or HEVs due to insufficient energy density. Therefore, new battery systems such as Li–air batteries with high theoretical specific energy are being intensively investigated, as this technology could potentially make long-range EVs widely affordable. So far, Li–air battery technology is still in its infancy and will require significant research efforts. This review provides a comprehensive overview of the fundamentals of Li–air batteries, with an emphasis on the recent progress of various elements, such as lithium metal anode, cathode, electrolytes, and catalysts. Firstly, it covers the various types of air cathode used, such as the air cathode based on carbon, the carbon nanotube-based cathode, and the graphene-based cathode. Secondly, different types of catalysts such as metal oxide- and composite-based catalysts, carbon- and graphene-based catalysts, and precious metal alloy-based catalysts are elaborated. The challenges and recent developments on electrolytes and lithium metal anode are then summarized. Finally, a summary of future research directions in the field of lithium air batteries is provided.
Sulfur encapsulation with nanoporous carbon is a widely adopted approach for Li–S batteries, but this often results in low sulfur utilization and low volumetric energy density. Here the authors report a non-encapsulation approach for the growth of S-containing species with low-surface-area carbon and high energy.