batterydata/paper-abstracts huggingface dataset:
Quantitative data on the thermal behavior of lithium ion batteries under charging and discharging conditions are essential for designing thermal management systems and improving battery safety. In this work, commercial 40 Ah lithium ion pouch cells with Li(Ni1/3Mn1/3Co1/3)O2 cathodes were tested under isoperibolic and adiabatic conditions in an Accelerating Rate Calorimeter at different charging/discharging currents from 5 A to 40 A. Adiabatic tests simulate the worst-case scenario of a battery pack without cooling. For charging and discharging an overall exothermic behavior was found and a total temperature increase for one half cycle between 3 and 11 K. Isoperibolic tests simulate a single cell under constant environmental temperature. Here an exothermic behavior for discharging and an endothermic behavior for charging were observed. To transfer the measured temperature changes into heat data, the effective specific heat capacity and the heat transfer coefficient were determined. For the first time the heat generation data for a large format pouch cell have been determined using both isoperibolic and adiabatic conditions. These data were compared with the total heat data calculated as the sum of reversible and irreversible heat that were measured by potentiometric and current interruption techniques respectively. A good agreement was found between all three heat generation determination methods.
Castor bean (Ricinus communis L.) plantlets were exposed to lead to study the detoxification mechanism. The results showed that castor bean could survive in soils spiked with 800 mg/kg dry weight Pb for 30 days and grew normally without suffering phytotoxicity. Lead is accumulated mostly in the roots while a small quantity is translocated to the leaves. Changes were detected in both pattern and intensity of Ascorbate peroxidase isoenzyme, while, in case of Guiacol peroxidase, Superoxide dismutase and Glutathione reductase isoenzyme changes were detected only in the intensity. The band intensity of all the isoenzymes increased with the increase of extraneous lead. Increased amount of Malondialdehyde was indicative of lipid peroxidation and free radical generation under lead stress while increased level of proline pointed to the occurrence of mechanism of scavenging free radicals. A decline in chlorophyll content was observed under lead stress. In contrast, carotenoid content was increased in the treated plants. Semi-quantitative reverse transcriptase-PCR was performed to study the expression of an ATP binding casette transporter under lead stress. The expression of the ATP binding casette transporter was recorded only in roots and not in the leaves. The expression was maximum in 800 mg/kg dry weight lead treated plants. These results show that R. communis has a high tolerance and low avoidance to lead.
Minute Li2MnSiO4 nanorods embedded in carbon nanofibers (LMS/CNFs) are prepared via an ethanol-based solvothermal process, and then by electrospinning and subsequent carbonization processes. The LMS nanorods (NRs) have lengths and widths of 15–20nm and 5nm, respectively, and grow lengthwise, i.e., along the [010] direction, which facilitates Li-ion transport in the LMS during charging/discharging. In addition, these LMS NRs are well incorporated in the electrospun LMS/CNFs after carbonization. The LMS/CNFs exhibit an excellent cycling stability with a capacity retention of 96% for up to 150 cycles at voltages of 1.5–4.75V vs. Li/Li+ and a current rate of 33.3mAg−1. The cycling stability of the LMS/CNFs results from the nano-architecture formed between the LMS NRs and the CNFs.
Publisher Summary This chapter reviews the findings of functional imaging of brain aging using two main approaches: studies of “resting” brain perfusion and metabolism; and activation studies. Aging affects the activation pattern underlying the process of encoding of faces; aged subjects do not show the right hippocampus and left prefrontal activation observed in young subjects. Also, the activation patterns do not differ significantly during the face recognition task, and there are no age differences in reaction time, but significant differences are found in recognition performances. Instead of the activation in the anterior prefrontal region observed in young subjects, elderly people show posterior frontal activation, in the vicinity of Broca's area. The statistical parametric mapping method has been used in aging studies to map the significant linear correlations between a given study variable and the age of the subjects. This method is highly suited for the investigation of the effects of aging on brain perfusion and metabolism because it allows a systematic, voxel-by-voxel analysis of the entire brain volume; a pictorial, visually straightforward representation of the findings; and a precise anatomical localization of the significant changes referenced to Talairach's system, permitting objective comparison between studies.
Understanding mass transport mechanisms in VRFB electrodes is critical to improving performance, efficiency, and depth-of-discharge. In this study, diffusion and convection are experimentally investigated in a VRFB test bed using a strip cell architecture, having only one straight channel and 1 cm2 active area. To study diffusion and convection-dominated mass transport regimes, various channel depths (0.25, 0.5, 1, 2.5 mm) are employed. The diffusion-dominated condition is imposed with deeper channel depths while convection-dominated condition is achieved with shallower channel depths. It is found that diffusion-dominated cells have large current gradients; convection-dominated cells have relatively uniform current distribution from inlet to outlet under a mass transport limited condition. Although increasing flow rate is frequently found to improve electrochemical performance, it is observed that there is no discernible change in current distribution when increasing flow rate in diffusion-dominated VRFB cells. Pressure drop tests also show that superior electrochemical performance can be achieved with reduced relative pressure drop in convection-dominated cells. In light of such findings, an optimization point is proposed for the strip cell architecture; such a point will vary with any other architecture and system, but this approach can be applied to any flowing system.
Using a novel electrodeposition/thermal process, V6O13+y , 0<y<2, bronzes were directly fabricated into a coin cell without the use of binders or electronic conductors. Transport properties of lithium insertion and removal from V2O5 and nonstoichiometric (ns) V6O13+y bronzes, were examined by electrochemical methods in asymmetrical Li/Li x V6O13+y cells. Diffusion coefficients in the range 0.2–5.0×10−8 cm2 s−1 were found for insertion and removal steps in the range, x=0–1.0. The transport of lithium ions from the vanadium oxides is similar to the insertion process. These bronze cathodes have similar transport properties to composite cathodes, making them potentially useful for electrochromic displays and microbatteries.
Carbon nanotube (CNT) wired and oxygen-deficient MoO3−x /CNT structures are fabricated via a facile hydrothermal reaction followed by controlled reduction in Ar/H2. The MoO3−x /CNT, which consists of 63 mol% MoO3 and 37 mol% MoO2, exhibits a much improved Li-storage property compared with the original MoO3/CNT structure when evaluated as an anode in the 0.05–3.0 V region. It is able to retain a capacity of 421 mAh g−1 towards Li after 100 cycles at 200 mA g−1, and deliver 293 and 202 mAh g−1 at current densities of 2 and 4 A g−1, respectively. It is suggested that the formation and recovery of a metallic MoO2 phase over the conversion reaction may account for the enhanced performance.
Efficient energy storage in the form of batteries contributes to building sustainable society. As advanced batteries need positive electrode materials capable of larger capacity, higher voltage, and lower cost, it is important to search for novel electrode materials. Among various inorganic/organic materials, cyanido-bridged coordination compounds are promising candidates for battery electrodes due to their ability to undergo solid-state redox reaction associated with ion (de)intercalation. In this review, recent results about the thermodynamic and kinetic aspects of the solid-state electrochemistry of cyanido-bridged coordination compounds are summarized, providing a fundamental basis toward developing cyanide electrodes for advanced batteries.
In this work, Co(OH)2 and Co3O4 films have been obtained using a solution to leach the cathodes of spent Li-ion batteries. The Co(OH)2 is electrodeposited onto conductive glass by the application of −0.85 V, with a charge density of 20 C cm−2, and its efficiency is found to be 66.67%. The Co3O4 film is obtained by heat treatment of the Co(OH)2 film at 450 °C for 3 h, in an air atmosphere, with a conversion efficiency of 64.29%. The cyclic voltammetry of Co(OH)2, in KOH 1.0 mol L−1 shows: three anodic peaks in the first cycle associated with the oxidation of Co(OH)2 to Co3O4, the conversion of Co3O4 into CoOOH, and the formation of CoOOH to CoO2 and the oxidation of water. The absence of cathodic peaks shows that oxidation from Co(OH)2 to CoO2 is an irreversible process. For the Co3O4 electrode, this verifies the existence of a redox pair associated with reversible oxidation of the Co3O4 to CoO2. The Co3O4 obtains a charge efficiency of 77% for the first 10 cycles (1.0 mV s−1) and a specific capacitance of 31.2 F g−1 (1.0 mV s−1) and 10.5 F g−1 (10 mV s−1). Co3O4 films have promising applications as pseudocapacitors.
Multivalent-ion batteries (MVIBs) provide economical and energy-dense alternatives to Li-ion batteries. In the academic pursuit to finding high-performance beyond Li-ion batteries, identifying a suitable cathode is a primary issue. More specifically, a cathode that supports high energy density, competitive charge/discharge rates, diffusion kinetics, and cyclability is desireable. In this regard, we computationally investigate layered TiSe 2 as a cathode for beyond Li-ion batteries. We find voltages as high as 2.0, 2.0, 1.1, and 1.8 V for Li, Na, Mg, and Ca respectively. We compute voltage profiles, diffusion energy barriers, and formation energies, as well as consider the impact of swelling and electronic properties. While we consider several intercalants, we are especially interested in Ca, which we find to experience an energy barrier of approximately 0.4 eV, similar to the energy barrier experienced by Li, and lower than that of Mg. While Mg is the popular choice for multivalent-ion battery materials, we find that TiSe 2 is able to accept more Ca per formula unit than Mg, and exhibits higher voltages than Mg, while experiencing improved diffusion kinetics. We advocate for the exploitation of TiSe 2 layered cathodes for beyond Li-ion batteries, and especially for Ca-ion batteries.
Graphite/LNMO cells show severe capacity fade after being stored for one week at 55 °C in the fully discharged state. The failure mechanism of the cell has been investigated by electrochemical methods and physical analysis techniques (XRD, SEM, FTIR and ICP-OES). Independent electrochemical analysis of anode and cathode extracted from the ET-stored cell suggests that both electrodes have significant capacity loss. It was observed that capacity loss of the aged cathode can be recovered by charging at a constant high potential (4.9 V vs. Li/Li+), while that of the aged anode cannot be recovered with a constant potential charge (10 mV vs. Li/Li+). Capacity fade for the LNMO cathode is attributed to sluggish kinetics of Li+ intercalation/deintercalation during cycling. Ex-situ surface analysis of the electrode reveals that the sluggish electrochemical kinetics is related to the formation of inactive surface layer on the cathode. Failure of the graphite electrode may result from Mn deposition and subsequent dissolution of the SEI layer on the anode.
In this study, a novel metal oxide–reduced graphene oxide (RGO) composite structure, denoted as a “nanobubble-decorated RGO sphere,” was fabricated and characterized for potential use in Li+-ion batteries. The nanobubble-decorated RGO sphere consists of an RGO sphere uniformly decorated with hollow metal oxide nanopowder. Reduction of the composite powder prepared by spray pyrolysis under H2/Ar gas mixture formed RGO spheres decorated with metal nanopowders. The metal nanopowders were transformed into hollow metal oxide nanopowders, or nanobubbles, by the nanoscale Kirkendall diffusion process. Cobalt oxide nanobubble-decorated RGO spheres, prepared as the first target material, showed excellent Li-storage properties. The cobalt oxide–RGO composite powders, tested at the current density of 2Ag−1 for 200 cycles before and after the nanoscale Kirkendall diffusion, showed discharge capacities of 932 and 1156mAhg−1, respectively; their capacity retentions measured from the second cycle onward were 89% and 99%, respectively.
Dynamic charge acceptance (DCA) is a key requirement for batteries in micro-hybrid vehicles. In automotive applications, DCA reaches a stable level during several weeks or months in service. A conditioning method that accelerates stabilizing DCA is presented. Various test methods for evaluation of DCA are compared. This is necessary for comparing new technologies (e.g. negative electrodes with carbon additives) and cell concepts (e.g. bi-polar batteries).
In this paper we propose the exploitation of TiO2 nanotube arrays as biocompatible electrodes for implantable supercapacitors. TiO2 nanotubes are obtained by anodic oxidation of titanium foil and the assembly of the whole energy storage device is conducted using only biocompatible materials: PDMS is selected as packaging material both for its biocompatibility and easy fabrication process, glass-fiber filter acts as separator and the Dulbecco’s Phosphate Buffered Saline solution as physiological electrolyte. Electrochemical characterizations of the proposed flexible device reveal promising performances of TiO2 nanotubes array for future implantable supercapacitors.
The anion influence on the volume changes of polyaniline (PANI) thick films (∼200μm) during redox switching was studied using voltammetric experiments with simultaneous microscopical observation. The area occupied by the polymer film in the microscope images was measured and used to compute the film volume and its variations. It is found that the electrolyte anion has a definite influence on the film volume changes. When a film equilibrated with perchloric acid is transferred to sulphuric acid, fully reduced and relaxed and afterwards subject to voltammetric cycling, a net volume increase is observed, spanning several potential cycles until a stationary profile is reached. This change is not reversed when the film is transferred back to perchloric medium, and in this electrolyte the response shows a faster evolution. Exchanges with hydrochloric acid show behaviour more similar to HClO4. IR measurements show that anion exchange is complete before the voltammetric cycling is started, indicating that anion ingress/exchange alone is not the only cause for PANI volume changes. The results are interpreted in terms of polymer backbone conformational changes and polymer/anion interactions.
The aim of the present study is to evaluate whether the effects of a short, six session version of an evidence-based parent training programme (The Incredible Years), delivered in a non-clinical community sample in the northern Norway, are maintained 4 years following the initial intervention.
A new compound Li–Ni–Ti oxide-based material (LiNi0.5Ti0.5O2) with cubic structure was prepared by solid state reaction at 900°C. Powder X-ray diffraction (XRD) was used to determine the phase purity and structure of the material. The Bragg peaks of LiNi0.5Ti0.5O2 can be indexed based on a cubic unit with dimension a =4.142Å, belonging to space group Fd3m (SG number 225). X-ray photoelectron spectroscopy (XPS) study showed that the chemical valences of Ni and Ti were +2 and +4, respectively. The electrochemical testing indicated that the Li+ ions in LiNi0.5Ti0.5O2 cannot be extracted until 4.8V. However, two initial Li ions per LiNi0.5Ti0.5O2 can be intercalated into LiNi0.5Ti0.5O2 and one Li+ ion can be extracted reversibly.
The aim of this study was to predict the wind energy content over the campus area of Izmir Institute of Technology. The wind data were collected at 10 and 30m mast heights for a period of 16 months. Mean wind speeds were 7.03 and 8.14m/s at 10 and 30m mast heights, respectively. The ‘WAsP’ and ‘WindPRO’ softwares were used for the wind statistics and energy calculations. Suitable sites were selected according to the created wind power and energy maps. Wind turbines with nominal powers between 600 and 1500kW were established for annual energy production calculations and best fitted ones were used for the micrositting.
Introduction The use of virtual simulators together with hospital practicals during undergraduate training can improve basic surgical skills, and may even be an important motivating focal point. The aim of this work is to determine the endoscopy skill level and its learning curve in three stages within the Medical degree (second, fourth, and sixth year) using a virtual simulator. Material and methods The Lapsim® simulator with 7 basic modular exercises was used. Twenty-four students (8 second, 8 fourth, and 8 sixth year) were subjected to a training program (basic test plus 3 sessions), and an examination at 30 days. A control group (n=24) from each year was subjected to 2 examinations with an interval of 30 days. Results All the groups improved significantly after training, and this was maintained in all the exercises after a “wash out” period of 30 days. All the groups achieved lower baseline scores in the “Cutting” and “Lifting and grasping” exercises, considered of intermediate level than any of the others. However, after the training process, they were the only exercises that the sixth year students demonstrated that they were clearly superior to the rest of the years: “Cutting” (94.5%±11% vs 81%±7%) (P<.05), “Lifting and grasping” (88.1%±13% vs 68%±11%) (P<.001). Conclusions The virtual simulator appears to be of greater use for those students in higher years with more clinical experience, there already being a discrimination process during this period. Surgical skills during this phase should be reinforced by means of new teaching challenges, such as simulation programs in the framework of skills laboratories.
The ever-increasing number of connected objects requires novel ways to power them and make them fully autonomous. In this context, photovoltaic, piezoelectric or thermoelectric energy-harvesting technologies show great promises as they make possible the conversion of solar radiation, motion or thermal energy into useful electricity for charging micro-batteries for instance. Thermoelectric micro-generators (μ-TEGs) exhibit several key benefits, making them prime candidates for harvesting any temperature difference between their two exchange surfaces. However, their output power critically depends on the design of the μ-TEG, the minimization of the detrimental influence of the contact resistances and on the coupling of the μ-TEG with the heat source and heat sink. Here, we theoretically and experimentally demonstrate how these inherent difficulties can be mitigated using an innovative flexible μ-TEG design based on bismuth telluride thin films. Our experimental results show that an output power of 5.5 μW per thermocouple can be generated under a temperature difference of only 5 K, in excellent agreement with predictions based on three-dimensional finite element analyses. These remarkable results rank our μ-TEG among the best micro-generators currently available.
Cathode Li[Li0.2Ni0.17Co0.16Mn0.47]O2 was prepared by solid-state reaction on various sintering process. It is shown that all the samples are homogeneous with smooth crystals from XRD patterns and SEM images. The particle size of the materials grows bigger with the increase of the sintering temperature. The charge–discharge tests demonstrated that the initial capacity of the compound increases with increasing in calcining temperature and decreasing in calcining time. The sample synthesized by a secondary sintering process has good crystallity, and excellent electrochemical performance. It delivered the largest initial discharge capacity (195.1mAhg−1) and reached the highest value of 214mAhg−1 at the 8th cycle, and still retain 179.5mAhg−1 after 40 cycles.
The first run of continuous hydrothermal leaching of lithium-ion battery cathode materials, LiCoO2, was performed using citric acid as the leachant at 200 °C. The flow system was specially designed and customized. Prior to the hydrothermal leaching experiments, a three-layer model was used to predict the flow state in this flow system, and a cold flow test using two kinds of flow lines was performed to determine the conditions in the preliminary experiments. Finally, the pulp density of the slurry and the flow rate were set to 10 g L−1 and 30 ml min−1, respectively, for the continuous hydrothermal leaching experiments. At 60 min after the start of slurry feeding, the leaching efficiency of Li and Co reached 81.3% and 92.7%, respectively, and can continue to increase with the extension of time. The successful run indicated that the process of hydrothermal leaching is feasible and promising to be applied in practice. Meanwhile, a problem of acid corrosion caused by the use of citric acid during this process was revealed and is expected to be resolved using inner coating materials with high acid corrosion resistance or organic acids with low or no acid corrosion as the leachant.
A simple one step hydrothermal route to Li1+xMn2−yO4 spinel compounds (x = 0.01–0.06, y = 0.02–0.09) via reduction of commercially available potassium permanganate with common organic reductants (alcohols, acetone, hex-1-ene, and isobutyraldehyde) in lithium hydroxide aqueous solutions is developed. The cubic spinel phase with no other impurities can be isolated after short reaction times (∼5 h) at the relatively low temperature of 180 °C. Scanning electron microscopy imaging reveals that the crystalline products have a distribution of sizes; the majority of the sample is composed of smaller particles between 10 and 30 nm. However, there are noticeably larger 100–300 nm interspersed particles—more prevalent in reactions with acetone and isobutyraldehyde. In corresponding benchtop test reactions, UV-Vis spectroscopy shows that the disappearance of MnO4− occurs more rapidly when acetone and isobutyraldehyde are used as reducing agents. Cyclic voltammetry performed on our spinels prepared via hydrothermal synthesis shows three reversible redox processes: a wave with E1/2 of ∼2.9 V (vs. Li/Li+) and two close waves between 4.05 and 4.15 V. Galvanostatic cycling of a cell composed of Li1.02Mn1.96O4 prepared from the oxidation of acetone between 3.5 and 4.4 V demonstrates a specific capacity of 104 mA h g−1 on first discharge, with ∼87% capacity retention (90 mA h g−1) after 100 cycles. The specific capacity of all samples correlates with the rate of disappearance of MnO4− observed in our benchtop reactions, providing a facile way to control particle size and electrochemical behavior.