batterydata/paper-abstracts huggingface dataset:
Lithium-ion capacitor is a hybrid electrochemical energy storage device which combines the merits of lithium-ion battery and electric double-layer capacitor. The precise state of charge estimation is essential to utilize lithium-ion capacitor efficiently. In this paper, the electrical characteristics of lithium-ion capacitor have been studied and the corresponding equivalent circuit model is established. Then, an adaptive square root cubature Kalman filter with variable forgetting factor recursive least square has been proposed to achieve state of charge estimation at each sampling step. The proposed method identifies the model parameters and noise statistics in real time, leading to obtain accurate SOC estimation even if the method is initialized with inaccurate parameters. Estimations under four working conditions are quantitatively studied, the experimental results show that the proposed method has better performance and the corresponding maximum root mean square error is controlled within 1%. Furthermore, the verification of robustness illustrates that the proposed method remains stability and acceptable accuracy when external interference and inaccurate initial SOC are included.
Carbon-coated LiCoPO4 particles are synthesized by one-pot hydrothermal process using three different organic additives (carboxymethylcellulose sodium salt (CMC), glucose, and ascorbic acid). The effect of the organic additives on particle size, morphology, nature of carbon coating, and electrochemical property of the resulting LiCoPO4 is investigated. CMC plays important roles to decrease the particle size and form well-covered carbon coating on the surface. Carbon-coated LiCoPO4 prepared using CMC delivers higher initial discharge capacity of 135 mA h g−1 at 0.1 C, and shows superior rate capability and cyclic performance than the other samples. The improved electrochemical characteristics are attributed to not only the fine particle which allows facile electronic and ionic transport, but also the high coverage of carbon coating which improves the electrical conductivity and prevents the irreversible reactions of the charged LiCoPO4 with electrolyte.
The performance of modern lithium-sulfur (Li/S) battery systems critically depends on the electrolyte and solvent compositions. For fundamental molecular insights and rational guidance of experimental developments, efficient and sufficiently accurate molecular simulations are thus in urgent need. Here, we construct a molecular dynamics (MD) computer simulation model of representative state-of-the art electrolyte–solvent systems for Li/S batteries constituted by lithium-bis(trifluoromethane)sulfonimide ( LiTFSI ) and LiNO 3 electrolytes in mixtures of the organic solvents 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL). We benchmark and verify our simulations by comparing structural and dynamic features with various available experimental reference systems and demonstrate their applicability for a wide range of electrolyte–solvent compositions. For the state-of-the-art battery solvent, we finally calculate and discuss the detailed composition of the first lithium solvation shell, the temperature dependence of lithium diffusion, as well as the electrolyte conductivities and lithium transference numbers. Our model will serve as a basis for efficient future predictions of electrolyte structure and transport in complex electrode confinements for the optimization of modern Li/S batteries (and related devices).
In order to improve the power performance of the lithium ion battery based on lithium iron phosphate (LiFePO4), a new methodology using a three-dimensional micro-porous current collector was described. The three-dimensional current collector was manufactured based on foamed polyurethane and nickel–chromium alloy. The cell using the three-dimensional current collector exhibited a superior high-rate discharge capability as compared to a conventional-type cell using the aluminum foil current collector. Furthermore, impedance analysis revealed the size reduction of a semicircle for the charge-transfer resistance by applying the three-dimensional current collector, which indicates a superior current collecting ability for the developed substrate.
There is a growing interest in direct thermal-to-electric energy conversion using solid state devices such as thermophotovoltaic (TPV) generators. TPV devices convert thermal radiation from heat sources into electricity without involving any moving parts. TPV opens up possibility for efficient and stand-alone power generation in boilers and furnaces. In this paper, a TPV integrated boiler was designed, built and investigated for micro combined heat and power (micro-CHP) application in residential buildings. A full size gas fired residential boiler was used as a precursor for integration with TPV devices. Experiments were conducted with the prototype TPV boiler so as to evaluate various issues related to this new technology. The electric output of TPV modules installed in the boiler was characterized under different operating conditions. The TPV cell modules generated 246.4W at an emitter temperature of 1265°C, which would be enough to power the electrical components of the whole heating system. Moreover, such a TPV integrated boiler could be employed to form a micro-CHP system in residential homes, providing an effective means for primary energy savings, on-site power and energy security.
A wind energy producer participating in deregulated markets needs to make contracts on the energy it will supply in the next day. Deviations from the contracts, which could occur due to wind uncertainties, are compensated in real-time balancing markets at a considerable cost. Therefore, developing advanced day-ahead bidding and real-time operation strategies minimizing such imbalance costs constitutes an important problem. There are several works on finding optimal day-ahead bids but the real-time operation problem is not studied well. Motivated by this fact, we propose a new strategy in which the day-ahead bids are computed by solving a risk-averse stochastic program, and real-time operation is performed by a stochastic model predictive control-based algorithm with a risk control capability. The algorithm is applied to a realistic system composed of wind farms and a pumped hydro storage plant. Its performance is compared to a number of approaches appearing in the literature. Because the problem considered has two conflicting objectives of profit maximization and risk minimization, a Pareto optimality analysis is also conducted. Finally, the validity of a common practice followed in the literature, which is estimating the economic performance by bidding optimization, is investigated by comparing the estimate with the actual performance achieved by real-time operation methods.
Few studies have examined the effectiveness of cognitive behavior therapy to manage seizures and improve psychosocial functioning in older adults with epilepsy. This study evaluated the efficacy of a 6 week group CBT program in community dwelling adults with epilepsy who were aged over 60 years. A total of 37 participants were randomly assigned to either a CBT group or a control group. Measures of depression, dysthymia, psychosocial functioning and seizure frequency were completed at pre and post intervention. Seizure frequency was significantly reduced in the CBT group compared to the control group (Cohen’s d 0.63). The results suggest that the relationship between seizure frequency and psychological and psychosocial well being in older adults requires further investigation. Although there were no significant between group differences on measures of depression and psychosocial functioning, both the CBT and control groups improved significantly from baseline.
To improve the electrochemical performance of Si thin film, we have investigated the effect of the addition of Al in the film. The Si–Al thin film were prepared by co-deposition from Si target embedded with Al rods on Cu foil. The atomic ratio of Al in the film is 18.69% estimated by energy-dispersive spectroscopy. The XRD and TEM analysis revealed that the Si–Al thin film was a complete amorphous structure. The electrochemical performance of the Si–Al thin film as anode material for lithium ion battery was investigated by the cyclic voltammetry and charge/discharge tests. The Si–Al thin film delivered a high reversible capacity of 2257.8mAhg−1 and an initial Coulombic efficiency of 85.9% at 0.05C rates. Compared with pure Si thin film with the same thickness, Si–Al thin film showed superior rate capability and cycle performance. And the Li+ diffusion coefficient of Si–Al thin film is much higher than that of Si thin film.
Graphene nanosheets (GNs) with large specific surface area, high conductivity, and excellent flexibility were integrated with negative active materials (NAM) as backbones to construct a continuous conductive network to suppress the sulfation of negative plates and improve the cycle-life of lead–acid batteries (LABs) under high-rate partial state-of-charge (HRPSoC) condition. The microstructure of GNs was characterized by scanning electron microscopy (SEM), nitrogen adsorption–desorption techniques, fourier transform infrared (FTIR), and Raman spectroscopy. The effect of GNs at different contents in the electrochemical performances of negative plates and LABs is investigated. The electrochemical tests show that the cycle-life of LABs under HRPSoC conditions has improved by more than 370% and the utilization ratio of NAM has been raised to 63.7%, when 0.9 wt% additions of GNs was added to NAM. It is found that the GNs will be a promising carbonaceous additive for long cycle-life of LABs under HRPSoC conditions.
Metallic lithium, with super high theoretical specific capacity, enjoys great potential as an anode for rechargeable batteries. However, safety issues caused by lithium dendrite growth as well as limited cycling life restrict its practical application. Herein we validate that the application of a new dual-salt electrolyte composed of Lithium difluorophosphate (LiPO2F2) and lithium bis(fluorosulfony)imide (LiFSI) in the same proportion enables the improved long-term cycling performance along with high coulombic efficiency for lithium metal batteries. With 1 M LiPO2F2 and 1 M LiFSI in 1,2-dimethoxyethane as the electrolyte, a Li/Cu cell can be cycled at 1 mA for more than 300 cycles with a deposited capacity of 1.0 mAh. It also displays that a homogeneous and dendrite free solid electrolyte interphase layer is generated on the Cu electrode, which can be ascribed to the favorable stability of LiPO2F2 and high ionic conductivity of LiFSI. These results deliver perceptions for the advancement of high-performance lithium metal anode.
Air-cooled, self-humidifying hydrogen fuel cells are often used for backup and portable power sources, with a metal hydride used as the hydrogen storage material. To provide a stable hydrogen flow to the fuel cell stack, heat must be provided to the metal hydride. Conventionally, the heat released from the exothermic reaction of hydrogen and oxygen in the fuel cell stack to the exhaust air is used to heat a separate metal hydride container. In this case, the heat is only partially used instead of being more closely coupled because of the heat transfer resistances in the system. To achieve better heat integration, a novel scheme is proposed whereby hydrogen storage and single fuel cells are more closely coupled. Based on this idea, metal hydride containers in the form of cooling plates were assembled between each pair of cells in the stack so that the heat could be directly transferred to a metal hydride container of much larger surface-to-volume ratio than conventional separate containers. A heat coupled fuel cell portable power source with 10 cells and 11 metal hydride containers was constructed and the experimental results show that this scheme is beneficial for the heat management of fuel cell stack.
Colloidal synthesis method such as oleylamine (OAm)-stabilized process is of great interest for obtaining uniform and highly dispersed platinum nanoparticle catalysts, yet the ligand may unavoidably inhibit their electro-catalytic performance. Thus, fully removing these ligands is critical to activate catalyst surface. Previous research of OAm removal process pointed that thermal annealing was the most effective way in comparison with other methods such as chemical washing, UV–Ozone irradiation and cyclic voltammetry sweeping, but generally resulting in undesired growth of platinum nanoparticle. Few studies concerning a more efficient ligand removal process have been published yet. In this work we proposed a platinum in-situ catalytic OAm combustion strategy to elucidate the removal mechanism of OAm ligands in thermal process and the key experimental parameters were also optimized. In addition, heat flow signal based on differential scanning calorimetry (DSC) measurement as a sensitive indicator, is suggested to reveal the ligand removal efficiency, which is much more reliable than the traditional spectroscopy. In comparison with commercial Pt/C sample, such a surface clean Pt/C electrocatalyst has shown an enhanced specific activity for oxygen reduction reaction. Our removal strategy and the evaluation method are highly instructive to efficient removal of different organic ligands.
In the past 10–15 years, the microbial fuel cell (MFC) technology has captured the attention of the scientific community for the possibility of transforming organic waste directly into electricity through microbially catalyzed anodic, and microbial/enzymatic/abiotic cathodic electrochemical reactions. In this review, several aspects of the technology are considered. Firstly, a brief history of abiotic to biological fuel cells and subsequently, microbial fuel cells is presented. Secondly, the development of the concept of microbial fuel cell into a wider range of derivative technologies, called bioelectrochemical systems, is described introducing briefly microbial electrolysis cells, microbial desalination cells and microbial electrosynthesis cells. The focus is then shifted to electroactive biofilms and electron transfer mechanisms involved with solid electrodes. Carbonaceous and metallic anode materials are then introduced, followed by an explanation of the electro catalysis of the oxygen reduction reaction and its behavior in neutral media, from recent studies. Cathode catalysts based on carbonaceous, platinum-group metal and platinum-group-metal-free materials are presented, along with membrane materials with a view to future directions. Finally, microbial fuel cell practical implementation, through the utilization of energy output for practical applications, is described.
Publisher Summary This chapter focuses on the main techniques that have been developed to date for use in low power network systems. It presents the main techniques for low power lookup engines and low power network processors. Power consumption constitutes a significant issue in the emerging green computing environment. Network systems are special-purpose embedded computing systems. The power consumption of most network systems is constrained by their deployment environments. Many network systems are installed in densely utilized equipment racks. Limits on cooling of this equipment put a bound on how much energy can be consumed (and dissipated as heat). Some network systems are used in handheld, battery-operated systems or in application areas that require battery-operated, and thus power-limited, systems. The current state of the art of low power embedded system design does not enable the development of systematic approaches for power efficient systems overall; importantly, several results are developed for embedded subsystems, such as processors and sensors. For network systems, the major effort to date has been on the most power-consuming system components.
A novel C/Pb composite has been successfully prepared by electroless plating to reduce the hydrogen evolution and achieve the high reversibility of the anode of lead-carbon battery (LCB). The deposited lead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Because lead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogen evolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead. Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge–-discharge reversibility, which is attributed to the good connection between carbon additives and lead that has been stuck on the surface of C/Pb composite during the preparation process. The addition of C/Pb composite maintains a solid anode structure with high specific surface area and power volume, and thereby, it plays a significant role in the highly reversible lead-carbon anode.
The thermogravimetric (TG) and differential thermal analysis (DTA) were used to investigate the thermal stability of fully charged and discharged LiCoO2 cathode and graphite anode in nitrogen and air atmospheres. The results showed that the weight of charged and discharged LiCoO2 cathode samples exhibited an obvious decrease between 100 and 120°C in two atmospheres. The exothermic decomposition reaction of fully charged LiCoO2 cathode occurred at 250°C in two atmospheres. A small decomposition reaction of the discharged LiCoO2 cathode occurred at 300°C. When the temperature of samples was elevated to 600°C, the weight of fully charged and discharged LiCoO2 cathode in air atmosphere did not change; while the weight of samples in nitrogen atmosphere decreased. This was because the Co3O4 as the decomposition product of the cathodes could be reduced to CoO by the carbon black above 600°C in N2 atmosphere. The solid electrolyte interphase (SEI) film of fully charged and discharged graphite anode was decomposed at 100–120°C in two atmospheres, and the weight loss of fully charged graphite anode at 100–120°C was obviously less than that of the fully discharged graphite anode. When the samples were heated to 300°C, there was no fierce exothermic reaction for the lithiated graphite anode in N2 atmosphere, whereas an exothermic reaction in air atmosphere occurred rapidly.
This paper presents the results from a comparative study between two types of valve-regulated lead-acid battery cells, with uncoated and polymer composite coated absorptive glass mat (AGM) separators. The volt-ampere characteristics of the studied cells, recorded at different ambient temperatures, show that the cells with polymer coated separators have significantly lower overcharge (recombinant) current than the cells with conventional untreated AGM separator. During overcharge, the higher recombinant current in the cells with plain separator leads to higher cell temperature than that of the cells with polymer coated AGM separator. The possibility to avoid thermal runaway (TR) is also illustrated during polarization of the cells at 2.65 V. After 320 h, a conventional cell has C/4 current (trend to TR), while the cells with composite coating sustain low (C/26) constant current for long period of time (at least 650 h). The cycle life test indicates stable operation of the cells with coated separator, while the conventional cell reaches high recombinant current and thus, it is susceptible to thermal runaway phenomena.
In a previous behavioral study, we showed that parents of children with SLI had a subclinical deficit in phonological short-term memory. Here, we tested the hypothesis that they also have a deficit in nonverbal auditory sensory memory. We measured auditory sensory memory using a paradigm involving an electrophysiological component called the mismatch negativity (MMN). The MMN is a measure of the brain’s ability to detect a difference between a frequent standard stimulus (1000Hz tone) and a rare deviant one (1200Hz tone). Memory effects were assessed by varying the inter-stimulus interval (ISI) between the standard and deviant. We predicted that parents of children with SLI would have a smaller MMN than parents of typically developing children at a long ISI (3000ms), but not at a short one (800ms). This was broadly confirmed. However, individual differences in MMN amplitude did not correlate with measures of phonological short-term memory. Attenuation of MMN amplitude at the longer ISI thus did not provide unambiguous support for the hypothesis of a reduced auditory sensory memory in parents of affected children. We conclude by reviewing possible explanations for the observed group effects.
Cross-linked, self-supporting, membranes for lithium ion battery gel electrolytes were obtained by cross-linking a mixture of polyfluorosilicone (PFSi) and polysilicone containing ethylene oxide (EO) units [P(Si-EO)]. The membranes were also reinforced with nanosized silica. The two polymer precursors were synthesized with functional groups capable to form inter-molecular cross-linking, thus obtaining three-dimensional, polymer matrices. The precursors were dissolved in a common solvent and cross-linked to obtain free-standing PFSi/P(Si-EO):SiO2 composite films. The latter were undergone to swelling processes in (non-aqueous, aprotic, lithium salt containing) electrolytic solutions to obtain gel-type polymer electrolytes. The properties of the swelled PFSi/P(Si-EO):SiO2 samples were evaluated as a function of the electrolytic solutions and the dipping time. The PFSi/P(Si-EO):SiO2 membranes exhibited large swelling properties, high ionic conductivity and good electrochemical stability.
Genotoxicity assessment is important for predicting the carcinogenicity of chemical substances. p53R2 is a p53-regulated gene that is induced by various genotoxic stresses. We previously developed a p53R2-dependent luciferase reporter gene assay in the MCF-7 human breast adenocarcinoma cell line, and demonstrated its ability to detect genotoxic agents. In this paper, we investigate the applicability of the p53R2-based genotoxicity test in the human lymphoblastoid cell line TK6. TK6 cells that express wild-type p53 have been widely used for genetic toxicology studies. To evaluate the performance of the test system in TK6 cells, we referred to 61 of the chemicals on the list of 20 genotoxic and 42 non-genotoxic chemicals recommended for the evaluation of modified or new mammalian cell genotoxicity tests by the European Centre for the Validation of Alternative Methods. The overall accordance, sensitivity, and specificity of our results with the ECVAM list were 90% (55/61), 85% (17/20), and 93% (38/41), respectively. These results indicate that the p53R2-based genotoxicity test can detect various types of genotoxic chemicals without compromising its specificity. This test will be a valuable tool for rapid screen for identifying chemicals that may be genotoxic to humans.
The results of experimental research concerning the assessment of the permeability of porous materials with respect to gas flow are presented in this paper. The conducted research applied to, among others, chars (acquired from the UCG thermal process) with an anisotropic gap-porous structure and - for comparative purposes - model materials such as pumice and polyamide agglomerates. The research was conducted with the use of a special test stand that enables the measuring of gas permeability with respect to three flow orientations compared with symmetric cubic-shaped samples. The research results show the explicit impact of the flow direction on the permeability of chars, which results from their anisotropic internal structures. The suitability of calculation methods employed to calculate the hydrodynamics of the gas flow through porous materials was also evaluated.