batterydata/paper-abstracts huggingface dataset:
Wearable displays are considered as a bilateral communication tool in the hyperconnected era. Although several electronic clothing display was demonstrated, high power consumption issue still remained. Here, we present wireless powered wearable μLEDs (WμLEDs) with excellent stability. A custom-designed wireless power supply system operated a 30 × 30 WμLED array on a fabric. The WμLED stability was intensively investigated under bending, stretching, 85 °C/85% relative humidity and artificial sunlight conditions, showing the suitability of WμLED outdoor usage. Finally, a passive-matrix WμLED display successfully emitted a brilliant red glow on a fabric.
Fluorine doping of a compositionally graded cathode, with an average concentration of Li[Ni0.80Co0.05Mn0.15]O2, yields a high discharge capacity of 216 mA h g−1 with unprecedented cycling stability by retaining 78% of its initial capacity after 8000 cycles. The cathode is cycled at 100% depth of discharge (DOD), unlike the currently deployed layered cathode whose DOD is limited to 60–80% to compensate for capacity fading and guarantee the required battery life. Additionally, the capacity and cycling stability of the cathode easily surpass those of the existing state-of-the-art batteries, while achieving the energy density goal of 800 W h kg−1cathode for electric vehicles (EV) with ultra-long cycle life. The structural and chemical stabilities of the cathode were provided by the compositional partitioning and unique microstructure of the compositionally graded cathode combined with the ordered site-intermixing of Li and transition metal (TM) ions discovered via transmission electron microscopy. F doping induced the formation of a 2ahex × 2ahex × chex superlattice from ordered Li occupation in TM slabs and vice versa, which has been proven to be essential for suppressing microcrack formation in deeply charged states, while maintaining the structural stability of the cathode during extended cycling. Furthermore, the proposed cathode allows for the recycling of used EV batteries in energy storage systems, thereby alleviating the negative environmental impact by reducing the CO2 emissions and cost associated with disposing of dead batteries.
Composite positive electrodes for all-solid-state In/LiCoO2 cells with Li2S-P2S5 glass–ceramic electrolytes were designed in order to improve the high rate performances of the cells. The composite electrodes consisted of the active material, the solid electrolyte and carbon conductive additive powders. The cell with vapor grown carbon fiber (VGCF) as a conductive additive was charged and discharged at current densities of over 1mAcm−2, while the cell with acetylene black (AB) did not work as a rechargeable battery. The difference in the cell performances was explained from viewpoints of the morphology of the carbon additives. VGCF formed a more continuous electron conducting path in the composite positive electrode than AB. The cells without conductive additives were charged and discharged by increasing LiCoO2 content in the composite positive electrode. Using a suitable morphology and amount of component powders for composite electrodes is a key to improve rate performances of all-solid-state secondary batteries.
A concentrated nitric acid solution was used as an oxidant to modify the electrochemical performance of natural graphite as anode material for lithium ion batteries. Results of X-ray photoelectron spectroscopy, electron paramagnetic resonance, thermogravimmetry, differential thermal analysis, high resolution electron microscopy, and measurement of the reversible capacity suggest that the surface structure of natural graphite was changed, a fresh dense layer of oxides was formed. Some structural imperfections were removed, and the stability of the graphite structure increased. These changes impede decomposition of electrolyte solvent molecules, co-intercalation of solvated lithium ions and movement of graphene planes along the a-axis direction. Concomitantly, more micropores were introduced, and thus, lithium intercalation and deintercalation were favored and more sites were provided for lithium storage. Consequently, the reversible capacity and the cycling behavior of the modified natural graphite were much improved by the oxidation. Obviously, the liquid–solid oxidation is advantageous in controlling the uniformity of the products.
We investigated the electrochemical behaviors of nonstoichiometric silicon suboxides (SiO x , for x = 0.17–1.34) as the anode material for lithium rechargeable batteries. The amorphous SiO x (a-SiO x ) films were synthesized by reactive evaporation of Si with oxygen gas. The initial charge (lithiation) and discharge (delithiation) capacities were strongly related to the value of x in SiO x . We proposed an electrochemical reaction model of SiO x with lithium (Li) to describe the relationships quantitatively by assuming SiO x was composed of a reversible Si and an irreversible SiO2 component. Lithiated products were identified by XPS as a fully lithiated Si, Li2O, Li silicates (Li4SiO4, Li2SiO3), and SiO2. After discharge, a portion of the Li in Li–Si was found to remain undischargeable as Li z Si (z; the function of x). This was an additional factor of the irreversible capacity. Peak positions assigned to Li z Si in XPS Si2p spectra suggest that the value of z depends on the value of x. The a-SiO x (for x = 1.02, 1.34) films demonstrated excellent cyclability at a range of 0.005–1.5 V vs. Li/Li+. Absence of peaks at 0.45 V in differential capacity vs. voltage (dQ/dV) profiles indicates the suppression of crystallization of lithiated a-Si, even under deep cycle conditions.
Using the pressure-pulsed chemical vapor infiltration technique, thin pyrocarbon films were coated on the surface of the hard-carbon particles. The crystallinity of pyrocarbon shell was higher than that of the core carbon. The BET surface area and the pores with the diameter of 1.5–5nm were extremely decreased after coating with 7wt.% pyrocarbon. These changes in the nano-scaled structure of carbon surface could lead to the reduction of irreversible capacity. The cycleability was improved by pyrocarbon-coating, which would be attributed to the increase of the surface roughness on sub-micron scale by coating with the pebble-like pyrocarbon film to increase the adhesion among the particles by the organic binders.
Extreme temperatures pose several limitations to electric vehicle (EV) performance and charging. To investigate these effects, we combine a hybrid artificial neural network-empirical Li-ion battery model with a lumped capacitance EV thermal model to study how temperature will affect the performance of an EV fleet. We find that at −10 °C, the self-weighted mean battery charging power (SWMCP) decreases by 15% compared to standard 20 °C temperature. Active battery thermal management (BTM) during parking can improve SWMCP for individual vehicles, especially if vehicles are charged both at home and at workplace; the median SWMCP is increased by over 30%. Efficiency (km/kWh) of the vehicle fleet is maximized when ambient temperature is close to 20 °C. At low (−10 °C) and high (+40 °C) ambient temperatures, cabin preconditioning and BTM during parking can improve the median efficiency by 8% and 9%, respectively. At −10 °C, preconditioning and BTM during parking can also improve the fleet SOC by 3–6%-units, but this also introduces a “base” load of around 140 W per vehicle. Finally, we observe that the utility of the fleet can be increased by 5%-units by adding 3.6 kW chargers to workplaces, but further improved charging infrastructure would bring little additional benefit.
An echelon internal heating method based on alternating current has exhibited many advantages of high heat generation rate and thermal uniformity for fast battery heating at low temperatures. However, inappropriate parameter settings for the echelon internal heating method are prone to risk battery health due to side reactions. To address this problem, a three-electrode cell is fabricated to investigate the effect of the echelon internal heating method on cell health at low temperatures. A fractional order circuit model is used to determine the optimal current amplitude and frequency of alternating current at different temperatures for preheating the cell. After many cycles of preheating the cell, capacity calibration results and incremental capacity curves show no apparent detrimental effect of the proposed heating method on cell health.
One of the most important considerations in the product life-cycle of an embedded project is to understand and optimize the power consumption of the device. Power consumption is highly visible for hand-held devices which require battery power to be able to guarantee certain minimum usage/idle times between recharging. Other main embedded applications, such as medical equipment, test, measurement, media, and wireless base stations, are very sensitive to power as well – due to the need to manage the heat dissipation of increasingly powerful processors, power supply cost, and energy consumption cost – so the fact is that power consumption cannot be overlooked. The responsibility for setting and keeping power requirements often falls on the shoulders of hardware designers, but the software programmer has the ability to provide a large contribution to power optimization. Often, the impact that the software engineer has on the power consumption of a device is overlooked or underestimated. The goal of this chapter is to discuss how software can be used to optimize power consumption, starting with the basics of what power consumption consists of, how to properly measure power consumption, and then moving on to techniques for minimizing power consumption in software at the algorithmic level, hardware level, and data-flow level. This will include demonstrations of the various techniques and explanations of both how and why certain methods are effective at reducing power so the reader can take and apply this work to their application immediately.
Odors, via the olfactory AWC neurons, trigger food searching in C. elegans. This study shows that the peptide NLP-1, co-released with glutamate from AWC neurons, acts to limit searching locomotion through a feedback loop that involves activation of the receptor NPR-11 on AIA interneurons and release of another peptide, INS-1, from the AIA neurons.
SnO2 nanoparticles (NPs)@carbon nanofibers as anode materials for lithium-ion battery are synthesized by a novel facile route using the commercial filter paper and tin dichloride dehydrate (SnCl2·2H2O). The weight ratio between carbon nanofibers and SnO2 NPs, which seriously affects the battery performance, has been demonstrated to be easily tuned by adjusting the sintering temperature. The electrochemical investigations show that the SnO2 NPs@carbon nanofibers with 9 wt% carbon have the best performance with the highest capacity of 383 mAh g−1 after 30 cycles at a current density of 100 mA g−1. The method introduced in this study provides an easy strategy for the controlled introduction of carbon to optimize the performance of lithium-ion battery using SnO2 NPs@carbon nanofibers as anode materials.
Lithium−sulfur (Li−S) batteries are promising to replace current commercial Li−ion batteries due to the high energy density. Despite this, the poor cyclic stability induced by the shuttle effect of electrolyte-soluble intermediate polysulfides is one of the great obstacles for the application of Li−S batteries. To overcome this issue, here we report a self-template synthesis of metallic and polar Co9S8 nanocrystals inlaid carbon (Co9S8/C) hollow nanopolyhedra as an efficient sulfur host material. The Co9S8/C hollow nanopolyhedra with large inner space can ensure the loading mass of sulfur and buffer the volume expansion of Li2Sx species during cycling; while the metallic and polar Co9S8/C shell offers synergetic spatial confinement and chemical binding to immobilize polysulfides and prevent the shutting effect. The Co9S8/C-S composite cathode exhibits high capacity and long cycle life with a low capacity decay of 0.041% per cycle over 1000 cycles at 2.0C. When the areal sulfur content is as high as 3.0mgcm–2, the Co9S8/C-S cathode still maintains high cycling stability.
The use of multivariate statistical methods in battery research is developed with examples drawn from the literature and unpublished work by the authors. The techniques discussed may be described in general as, data reduction, cluster analysis and regression methods for prediction. Individually or collectively these represent the three main areas of interest to battery researchers. Data reduction permits the visualization of the relationship between samples which are characterized by multiple measured variables. Cluster analysis extends this process to examine any natural groupings existing in the samples, based on the variables measured, and multivariate prediction is a calibration technique permitting the modelling of complex non-linear systems.
Ti3SiC2-modified LiFePO4/C cathode materials are prepared via a suspension mixing method followed by heat-treatment at 400 °C. The galvanostatic electrochemical measurements indicate that 4 wt% Ti3SiC2-modified LiFePO4/C exhibits the best electrochemical performances in the voltage range of 2.0–4.2 V. The sample shows the highest initial discharge capacity of 116.0 mAh g−1 at the rate of 0.1 C at −20 °C. And it keeps a capacity retention of 97.0% at 1 C at −10 °C after 100 cycles, higher than 81.2% for LiFePO4/C at the same conditions. Furthermore, Ti3SiC2-modified LiFePO4/C samples deliver lower charge-transfer resistance and higher diffusion coefficient of Li+ compared with the pristine LiFePO4/C, especially the 4 wt% Ti3SiC2-modified LiFePO4/C sample exhibits the lowest charge-transfer resistance and highest diffusion coefficient of Li+ among all the four samples. The improved electrochemical performances can be attributed to the lower charge transfer resistance and higher diffusion coefficient of lithium ions resulted from the modification of appropriate amount of Ti3SiC2. Besides, a series of electrochemical results show that the performances of the electrodes with 10 wt% super-P are superior to those of the electrodes with 5 wt% super-P.
In randomly deployed visual wireless sensor networks for surveillance applications, the scheduling of sensor nodes can be seen from the risk perspective: different parts of the area of interest may have different risk levels according to the pattern of observed events such as the number of detected intrusions. In this paper, we propose a multiple-level activity model that uses behavior functions to define application classes and allows for adaptive scheduling based on the application criticality and on the availability of multiple cover sets per sensor node. The paper then describes how an adaptive scheduling model can be defined in order to dynamically schedule nodes by varying the capture speed according to nodes’ environment. Simulation results are presented to validate the performance of the proposed approach in terms of percentage of active nodes, percentage of coverage and stealth time under intrusion scenarios.
The cell performance of lithium–oxygen batteries using nitrogen doped graphene as a catalytic cathode has been validated in recent research, but the cathode reaction mechanism of lithium and oxygen still remains unclear. Since the oxygen reduction reaction (ORR) mechanism by ionic lithium and catalytic surface is predicted to be distinct for different defective sites such as graphitic, pyridinic, and pyrrolic, it is necessary to observe the behavior of ionic lithium and oxygen gas at each defective site in nitrogen doped graphene. In this study, density functional theory (DFT) calculations are adopted to analyze at an atomic scale how effectively each defective site acts as a catalytic cathode. Interestingly, unlike pyridinic or pyrrolic N is known to be the most effective catalytic site for ORR in fuel cells. Among the other defective sites, it is found that the graphitic N site is the most effective catalytic media activating ORR by ionic lithium in lithium–oxygen batteries due to the electron accepting the reaction of Li–O formation by the graphitic N site.
Novel fabrication techniques have enabled increasingly controlled microstructural geometries in electrochemical energy devices, including dye-sensitized solar cells. An analytical tool, based on an electrochemical analogy to thermal fin analysis, has been developed to support the design of such microstructures. An adapted version of this tool is presented for analyzing the performance of microstructural geometry in dye-sensitized solar cells. This electrochemical fin model is capable of describing experimentally observed performance gains associated with specific microstructural geometries. The assessment of structures based on nanorod and nanoparticle architectures is addressed, and insights into trade-offs between surface charge transfer reactions and diffusive transport in solid photoelectrode phases are discussed.
Membranes of sodium bis(trifluoromethanesulfonate) imide (NaTFSI) complexed with poly(ethylene oxide) (PEO) salt have been prepared by a solvent-free hot-pressing technique with different EO:Na molar ratio. All membranes show good ionic conductivities in the range of 10−3 S cm−1 above 70 °C. However, the more NaTFSI-concentrated samples are sticky gums due to the plasticizing nature of the anion. The PEO20:NaTFSI sample exhibits the compromise of conductivity, thermal and mechanical properties. The addition of nanometric SiO2 to the PEO20:NaTFSI membranes further enhances their mechanical properties. Moreover, the PEO20:NaTFSI + 5 wt.% SiO2 membranes show similar ionic conductivity and similar anodic electrochemical stability in comparison to the ceramic free PEO20:NaTFSI sample. In a Na(s)/polymer electrolyte/Na(s) symmetrical cell followed up to 30 days, the presence of the ceramic filler slightly increased the interface resistance in comparison to the ceramic-free membrane. Nuclear magnetic resonance determinations of anion diffusion coefficients and Na+ mobility suggest that presence of filler may have a positive affect on the cation transference number that is in accordance with the t Na + transference number measurement.
This work reports a simple preparation method for spherical hard carbons and graphites. The phenolic resin and methylnaphthalene-derived mesophase pitch (MNMP) powders are employed as the precursor for hard carbon and graphite, respectively. The irregular-shaped precursor powders are converted to spherical carbons by first coating with fine-grained fumed silica powder and carbonizing/graphitizing under an argon atmosphere. Two characteristic features are observed in this preparation. First, among the used silica powders, only those having a hydrophobic surface group are effective for the irregular to sphere conversion. Second, the conversion takes place near the glass transition temperature of the resin and the softening point of the pitch, respectively. Based on these observations, an irregular to sphere conversion mechanism has been proposed. The spherical carbon powders exhibit a higher tap density and smaller surface area than those of the irregular-shaped ones, which is an advantageous feature for practical lithium batteries.
We report on electrochemical properties of NiO-blended spinel Li1.1Mn1.9O4 at elevated temperature (60°C). Thus, we employed two kinds of NiO powders, those are, larger particle size (>10μm) and submicron-sized NiO powders obtained by a ball-milling. These NiO powders were blended to the spinel Li1.1Mn1.9O4 as an additive for fabrication of cathode. The resulting discharge capacity for the larger NiO particle-blended Li1.1Mn1.9O4 had similar electrochemical properties to the bare Li1.1Mn1.9O4. On the other hand, submicron-sized NiO-blended Li1.1Mn1.9O4 brought about slightly increased capacity and excellent capacity retention, maintaining its initial capacity of 99.2% at 25°C and 94% at 60°C when Li metal was employed as the anode. In Li-ion cell using graphite as the anode, the capacity retention was of about 80% during cycling at 60°C, whereas C/Li1.1Mn1.9O4 cell retained around 68% of its initial capacity. Such improved properties would be ascribed to the HF scavenging into the electrolyte by presence of the submicron-sized NiO particles in Li1.1Mn1.9O4 cathode.
Polymer electrolytes based on poly(ethylene oxide), (PEO), can be prepared as either a crystalline or an amorphous phase. A previous study of the 6:1 PEO:LiSbF6 electrolyte by Gadjourova et al. [Nature, 412 (2001) 520] reported that the crystalline phase has a higher ionic conductivity than the amorphous phase. Because this behavior is opposite to what is observed in other polymer electrolytes, it is important to understand the phases and phase transitions of this system. To this end, a detailed temperature-dependent infrared spectroscopic study was performed on P(EO)6LiSbF6 crystalline material. The spectroscopic data are complemented by thermal analysis and X-ray diffraction measurements. These studies show that the published P(EO)6LiSbF6 crystal structure with 2000 molecular weight PEO is stable from −100 to 90°C. The onset of a thermal transition is observed at about 110°C, corresponding to a crystal structure change. The new crystalline phase melts at about 130°C. The crystal structure of P(EO)6LiSbF6 made from 100 000 molecular weight PEO is stable with no intermediate structure from −100°C to the melting transition at 130°C, where severe decomposition is also observed.
Supercapacitors (SCs) are playing a key role for the development of self-powered and self-sustaining integrated systems for different fields ranging from remote sensing, robotics and medical devices. SC miniaturization and integration into more complex systems that include energy harvesters and functional devices are valuable strategies that address system autonomy. Here, we discuss about novel SC fabrication and integration approaches. Specifically, we report about the results of interdisciplinary activities on the development of thin, flexible SCs by an additive technology based on Supersonic Cluster Beam Deposition (SCBD) to be implemented into supercapacitive electrolyte gated transistors and supercapacitive microbial fuel cells. Such systems integrate at materials level the specific functions of devices, like electric switch or energy harvesting with the reversible energy storage capability. These studies might open new frontiers for the development and application of new multifunction-energy storage elements.
Patients with acute ischemic stroke are at a higher risk of developing cognitive impairment which could be often attributed to cytokine activation.
Li-rich layered oxide is one of the most promising cathode materials for high-energy-density Li-ion batteries (LIBs). The composition, structure and morphology of precursors have significant influence on the electrochemical performance of the final cathode material. The capacity and initial coulombic efficiency of Li1.2Mn0.54Ni0.13Co0.13O2 can be simultaneously improved by sintering a nanoplate precursor with Li2CO3 in our previous work. Herein, the morphology and the formation mechanism of such nanoplate are investigated through a designed orthogonal tests. The optimal concentration of transition metal ions, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) and polyvinyl pyrrolidone (PVP) are 0.1, 0.031 and 0.004gmL−1, respectively. The as-prepared Li1.2Mn0.54Ni0.13Co0.13O2 from optimal nanoplate demonstrate an improved discharge capacity (323.8mAhg−1 at 20mAg−1), initial coulombic efficiency (81.3%), and rate capability (195.8mAhg−1 at 3C). This new precursor architecture opens a promising avenue for the development of high-performances cathode materials of LIBs.