batterydata/paper-abstracts huggingface dataset:
Lithium transport through vanadium pentoxide xerogel film electrode has been investigated in a 1M solution of LiClO4 in propylene carbonate by employing potentiostatic current transient technique and ac-impedance spectroscopy. From the comparison of the initial current experimentally measured with those initial currents theoretically calculated from the Ohm’s law and the Cottrell equation, it was confirmed that the cell-impedance-controlled constraint at the electrode surface is changed to the real potentiostatic boundary condition (diffusion-controlled constraint) when the potential step exceeds a critical value over the whole range of the lithium content. It was also found that the slope of the logarithmic current transient obtained at the lithium contents above 0.4 positively deviates in absolute value from 0.5 even under the real potentiostatic boundary condition, but the phase angle of the diffusion impedance under the semi-infinite diffusion condition negatively deviates in absolute value from 45° with increasing lithium content. With the aid of the X-ray diffractometry, the anomalous behaviours of the current transient and the diffusion impedance were discussed in terms of lithium transport through the interlayers with widely distributed spacings across the quasi-ordered xerogel film electrode. Furthermore, the current transient theoretically determined by employing the concept of interlayer spacing distribution coincided fairly well in form with that current transient experimentally measured.
The Tongue Display Unit (TDU) is a 144-channel programmable pulse generator that delivers dc-balanced voltage pulses suitable for electrotactile (electrocutaneous) stimulation of the anterior-dorsal tongue, through a matrix of surface electrodes. This article reviews the theory of operation and a design overview of the TDU, as well as selected applications. These include sensory substitution, tactile information display and neurorehabilitation via induced neuroplasticity.
A novel flame retardant, Resorcinol bis(diphenyl phosphate) (RDP), is successfully synthesized and investigated as electrolyte additive for lithium ion batteries. It is found that RDP can be electro-polymerized at 4.4 V (vs. Li/Li+), which will protect the batteries from voltage runaway by consuming the overcharge current. Moreover, RDP addition could lower the self-extinguishing time (SET) of the electrolyte. The influence of proper RDP addition on the cycling performance and capacity is negligible. Thus, RDP could be used as a novel electrolyte additive for lithium ion batteries functioned as both overcharge protection and flame retardant. The results may also be helpful for the further design of advanced lithium ion battery electrolytes.
The electrochemical response of different components such as carbon black (CB), binder, current collector and lithium salt have been examined in a general Li-ion battery context. The influence of these various components, alone and in different combinations, on composite graphite anodes and LiMn2O4 cathodes was addressed. CB electrodes were found to cycle with a reversible capacity of 180mAh/g between 0.01 and 1.5V, but with an irreversible capacity of 70%. The effect of adding CB to graphite electrodes was quantified in terms of first-cycle irreversible capacity and reversible capacity. Cyclic voltammetry measurements on CB electrodes were made in the same voltage region using different binders and electrolyte salts. A clear difference could be discerned between using EPDM or PVdF binder; extra reduction reactions were observed for the PVdF binder at 0.35V. The thermal behaviour of these binders in CB electrodes was also examined in the temperature range 30–300°C. The role of the anion in terms of thermal stability was also quantified from DSC measurements on both CB and graphite electrodes; the starting temperature for exothermal reactions involving SEI-layer reactions is clearly lower (∼60°C) for LiBF4 than LiPF6 (∼110°C) for both CB and graphite electrodes. Cyclic voltammetry in the cathodic region (3.0–5.5V) showed oxidation reactions between non-fluorinated binders, CB and LiPF6. These reactions could be avoided by changing to LiBF4. The electrochemical response on using fluorinated and non-fluorinated binders in this voltage region showed clear differences.
Three-dimensional (3D) TiO2 nanotube arrays grown on Ti mesh were prepared via the anodization process. The diameters of the Ti and TiO2/Ti wires and the length of the TiO2 nanotubes have linear relationships with the anodization processing time. When the anodization processing time is 600min, the TiO2/Ti mesh anode materials showed good capacity retention and high specific area capacity, without the need for a current collector or binder, due to their high surface area, high substrate utilization, and large active material loading rate per unit area. At the current density of 50μAcm−2, TiO2/Ti mesh with 600min anodization processing time has a stable discharge platform at 1.78V, and the specific area capacity is 1745.5μAhcm−2 over 100 cycles. By tuning the geometric parameters of the TiO2/Ti mesh and the anodization processing time, we can pave the way to finding TiO2/Ti mesh electrodes for lithium-ion batteries with high capacity per unit area and outstanding mechanical behaviour.
For conventional preparation methods of Li7La3Zr2O12 (LLZO) solid state electrolytes, there is a stereotype that higher density always comes from higher pressure enforced upon the LLZO pellets. In this paper, a different way with an auto-consolidation mechanism is provided and discussed. No pressing operations are employed during the whole preparation process. Due to the surface tension of liquid melted Li2O at sintering temperature, LLZO particles could aggregate together freely and automatically. The preparation process for dense LLZO is greatly simplified. A dense tetragonal LLZO with high relative density about 93% has been prepared successfully by this auto-consolidation method. And there are no voids observed in the SEM images. At 30 °C, the total conductivity is about 5.67 × 10−5 S cm−1, which is the highest one for tetragonal LLZO in the reported issues, even two times higher than that prepared by hot-pressing method. The activation energy for total conductivity is ∼0.35 eV atom−1 at 30–120 °C, slightly lower than the previous reported values. This work sheds light on the understanding of the consolidation mechanism for solid electrolytes and suggests a reliable route to syhthesize cemanic solid electrolytes.
The electrochemical performance and safety of high capacity free-standing anodes for lithium ion batteries have been enhanced by the addition of silicon to Ge-nanoparticle-single wall carbon nanotube (Ge-NP:SWCNT) hybrid electrodes. Materials characterization of electrodes indicated amorphous silicon was deposited through a low-pressure chemical vapor deposition (LPCVD) process resulting in a reduction in surface area from over 900m2/g to 113m2/g after 70%w/w addition of Si. Electrochemical performance of the electrodes showed extraction capacities over 1200mAh/g for Si–Ge-NP:SWCNT free-standing anodes with coulombic efficiencies of >85% on the first cycle; this demonstrates a >40% improvement over previous free-standing Ge-NP:SWCNT electrode capacities. The thermal safety of the Si–Ge-NP:SWCNT electrodes, as measured by differential scanning calorimetry (DSC), was also improved over pure SWCNT and Ge-NP:SWCNT electrodes, evidenced by a reduced exothermic energy release. These high capacity free-standing anodes show for the first time the use of nanostructured-tailoring to balance improvements in electrochemical performance and safety.
The phase transition of chromium substituted lithium manganese spinel oxide, LiCr y Mn2−y O4 was investigated by low-temperature powder X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and electrical resistivity measurements. The sample prepared at 820°C resulted in lowering the transition temperature T t with Cr composition y, whereas T t of the sample prepared at 750°C remained constant for 0≤y≤0.17 in LiCr y Mn2−y O4. This would be caused by a difference in distribution of the substituted Cr3+ ion in octahedral site depending on the preparation temperature. The phase transition was suppressed with increasing the amount of Cr content.
In the current work, graphite electrodes comprising PVDF binder and carbon black are subjected to characterization. An energy selective backscatter detector is used to localize carbon black and fluorine of PVDF. Therefore, it is necessary to distinguish between graphite, amorphous carbon and fluorine rich regions. Typically, an angular selective backscatter detector is employed to obtain an image providing the material contrast of the sample. Suitable materials for that detector are e.g. alloys to observe intermetallic phases, semiconductor for “channeling contrast”, or imaging SiO2 and Au nanoparticles in biological cells. However, this detector cannot be used to distinguish between light elements with low atomic numbers, such as C to P. In addition, the contrast of fluorine rich regions and graphite is poor in normal in-lens images due to the low difference of the atomic mass between C and F. The aim of this study is to enhance the contrast of fluorine rich regions to graphite to carbon black. Therefore, the energy selective backscatter detector is used and its advantages and setup is described. Finally this technique is applied to investigate 400 μm thick cross-sections of graphite electrodes dried at different temperatures and obtain the carbon black distribution.
Electric-powered transportation requires an efficient, low-cost, and safe energy storage system with high energy density and power capability. Despite its high specific capacity, the current commercially available cathode material for today's state-of-art Li-ion batteries, lithium nickel–manganese–cobalt oxide Li[Ni1/3 Mn1/3Co1/3]O2 (NMC), suffers from poor cycle life for high temperature operation and marginal rate capability resulting from irreversible degradation of the cathode material upon cycling. Using an atomic-scale surface engineering, the performance of Li[Ni1/3Mn1/3Co1/3]O2 in terms of rate capability and high temperature cycle-life is significantly improved. The Al2O3 coating deposited by atomic layer deposition (ALD) dramatically reduces the degradation in cell conductivity and reaction kinetics. This durable ultra-thin Al2O3-ALD coating layer also improves stability for the NMC at an elevated temperature (55 °C). The experimental results suggest that a highly durable and safe cathode material enabled by atomic-scale surface modification could meet the demanding performance and safety requirements of next-generation electric vehicles.
Publisher Summary This chapter discusses several design aspects that will help hardware and firmware work more efficiently to increase performance and reduce unnecessary waiting. In an embedded system, hardware and firmware each have their respective jobs to do but must work together as a system. Coordination must occur between hardware and firmware, especially to keep both working optimally. However, if the system is not balanced, performance could be impacted if firmware is waiting and vice versa. This chapter covers several aspects of hardware design. In the first section, the importance of ensuring that firmware was notified of any pertinent event that occurred in the block is presented. Also discussed are various ways of how firmware could know the task in the block was done. In the second section, it is discussed that how designs can impact the performance of the hardware/firmware interaction. It is then emphasized that how aspects of power-on and how firmware is not alive yet so the blocks must be designed to be self-sufficient until firmware can take over. The last section gives several ways of making more efficient the ability for firmware to communicate with and control the block.
In this paper, numerical and experimental studies are presented to determine the operating performance and power output from a vertical axis wind turbine (VAWT). A k-ɛ turbulence model is used to perform the transient simulations. The 3-D numerical predictions are based on the time averaged Spalart-Allmaras equations. A case study is performed for varying VAWT stator vane (tab) geometries of a Zephyr vertical axis wind turbine. The mean velocity is used to predict the time averaged variations of the power coefficient and power output. Power coefficients predicted by the numerical models are compared for different turbine geometries. The predictive capabilities of the numerical model are verified by past experimental data, as well as wind tunnel experiments in the current paper, to compare two particular geometric designs. The numerical results examine the turbine's performance at constant and variable rotor velocities. The effects of stator vanes on the turbine's power output are presented and discussed.
We analyzed spontaneous conversational humor production and response among 11 right hemisphere-damaged (RHD) patients, 10 left hemisphere-damaged (LHD) patients, 7 normal controls (NC), and their spouses. RHD patients and their spouses reported a statistically significant decline in the patients’ orientation to humor post-stroke. Also, we found a significant positive association between a RHD patient’s ability to decode prosody and their self-reported orientation to humor post-stroke.
In this paper, we propose a facile strategy to synthesize the porous structure TiO2@C composites through a two-step method, in which the precursor of MIL-125(Ti) was firstly prepared by solvent thermal method and then calcined under inert atmosphere. When employed as anodes for Na ion batteries, TiO2@C composites can exhibit a superior cyclability with a reversible sodium storage capacity of 148 mAh g−1 at the current density 0.5 A g−1 after 500 cycles and an excellent rate performance with a capacity of 88.9 mAh g−1 even the current reached to 2.5 A g−1 due to the dispersion of anatase TiO2 throughout amorphous carbon matrix and the synergistic effect between the anatase TiO2 nanocrystals and carbon matrix, which can availably enhance the electric conductivity and alleviate the volumetric variation of TiO2 during the insertion/extraction process of Na+.
Hydraulic cylinder is an indispensable linear actuator in high power applications like construction machinery. In order to reduce the energy consumption, the noise and the waste oil disposal pollution of the hydraulic cylinder control system, the most direct method is adopting the direct pump control technology which eliminates the throttle losses in the main power line. In such system, by changing the speed or the displacement of the pump, the pressure and volume flow will be matched with the need of loads. To date, research works in this field have been reported in many articles, but they are scattered and written in different languages. An overview which can summarize the latest development of this technology appears to be necessary. This paper provides a comprehensive review on this technology, aiming at clarifying recent advances and outlining potential challenges in the research and application of this technology. The review mainly covers three parts: system structure, control, and derived energy recovery system. Also the evolvement of the electro-hydraulic cylinder control system is introduced. The review indicates that attentions should be paid to the control and energy recovery plan of the direct pump controlled cylinder system, and to the newly proposed asymmetric pump controlled differential cylinder technology. It is envisaged that the information gathered in this paper will be a valuable one-stop source of information for researchers, as well as providing a direction for future research in this area.
WO3 thin film electrodes were successfully prepared by magnetron sputtering (MS) deposition under an oblique angle configuration (OAD). Intercalation of Na ions in the tungsten oxide layers has been studied using electrochemical techniques. Sample characterization before and after sodium intercalation has been carried out by Raman, XPS and XRD measurements. ToF-SIMS analysis has been also performed in order to analyze the element depth profiles along the electrode thickness. Electron microscopy evaluation of the cross section confirms the porous structure of the coatings. Batteries integrating these WO3 electrodes have a discharge capacity of 120 mA h g−1 at the initial cycles and show an adequate capacity retention upon 300 cycles. The WO3-OAD thin-films are proposed as promising electrodes for Na-ion batteries.
ABSTRACT A micro-nano structure based on polydopamine-grafted hollow carbon nanofiber–sulfur composite (HCNF@PDA–S) is designed as a cathode material for effective trapping of sulfur and polysulfides for lithium–sulfur batteries. Hollow carbon nanofiber@polydopamine (HCNF@PDA) micro-nano structure hybrid is first prepared by an in-situ polymerization dopamine monomer decorating on the surface of HCNFs and then elemental sulfur is infiltrated into the HCNF@PDA hybrid nanostructure by thermal treatment. The obtained HCNF@PDA–S composite shows the micro-nano structure based on the micron-sized hollow carbon nanofiber in length and nano-sized polydopamine grafted on the outer surfaces of the HCNFs with homogeneously distribution of sulfur. Compared with the HCNF–S composite, HCNF@PDA–S composite with a high sulfur content of approximately 80 wt% exhibits better electrochemical performance, which delivers initial discharge capacity of 800 mAh g−1 and maintains 530 mAh g−1 after 200 cycles at 0.5C rate. The enhancements of electrochemical performances may be attributed to the unique micro-nano hybrid structure based on HCNFs and PDA coating layer, in which the micro-sized HCNFs offer the electronic conductivity and provide a firm porous network of the cathode tolerating the volume expansion of sulfur cathode, and nano-sized PDA layers effectively prevent the dissolution of the polysulfides into the electrolyte.
Understanding the fundamental processes at the electrode/electrolyte interface during charge and discharge will aid the development of high-capacity Li-ion batteries (LIBs) with long lifetimes. Finite Element Methodology studies are here used to investigate the interplay between morphological changes and electrochemical performance in Si negative electrodes. A one-dimensional battery model including Solid Electrolyte Interphase (SEI) layer growth is constructed for porous Si electrodes in half-cells and used for simulating electrochemical impedance response during charge and discharge cycles. The computational results are then compared with experimental investigations. The SEI layer from the electrolyte decomposition products, different depending on the presence or absence of the fluoroethylene carbonate (FEC) additive, covers the electrode surface porous structure and is leading to an increasing polarization observed in the Nyquist plots during cycling. A continuous reformation of the SEI layer after each cycle can be observed, leading to consumption of Li+. The electrolyte composition also results in a variation of electrode porosity, which affects the performance of the cell. A more stable porous network is formed when using the FEC additive, rendering a reduction in polarization due to improved Li diffusion inside the electrode composite.
A small scale vertical axis wind turbine (VAWT) with axial flux permanent magnet (AFPM) generator is designed and the magnetic levitation method is used to increase the efficiency of this type of wind turbine. Magnetic levitation is inserted by using rare earth permanent magnets, the repelling force of magnets are used to suspend the rotating part of both the turbine and generator. Moreover, this design of simple generator which can easily drive without a geared mechanism, lessen cost and the complexity of the system by reducing the quantity of driving components. Three phase output is obtained from the designed generator which is converted into direct current through a three-phase rectifier to charge the batteries. The performance of proposed prototype is also tested experimentally. From the results it is found that the designed wind turbine performs optimally and efficiently as predicted by the developed design process.
A set of quinoline, cholesterol, and monopyranoside tagged ferrocene-chalcone-1,2,3-triazole triads was prepared via simple CuAAC. Physico and photoelectric consideration of these conjugates disclosed the advantage of the quinoline derivative for UV photodetector applications rather than being a photosensitizer for photovoltaic cells. In vitro antimicrobial assaying revealed interesting antimicrobial potency of the ferrocene-monopyranosyl conjugates.
Natural Killer (NK) cells are important in the first response against viruses and tumours. Compounds that modulate human NK cell activity offer interesting prophylactic and therapeutic options, however, a systematic screening tool is lacking. Development of suitable NK cell lines or receptor-based assays is hindered by the highly complicated regulation of the different NK cell subsets by multiple receptors. Here, we describe a cell-based flowcytometric activity assay adapted to identify NK cell modulating compounds. Fresh human peripheral blood mononuclear cells (PBMC) were incubated with NK-sensitive K562 target cells labelled with 5-(6)-carboxyfluorescein succinimidyl ester, followed by DNA-labelling with propidium iodide to identify dead cells. The assay demonstrated a good performance with an average Z′-factor of 0.6 and over 95% of the assays fulfilled the quality criteria, suggesting that it is possible to use a complex system with two different cell types to screen compounds. A large number of (natural) compounds and extracts were tested and normalized to the positive control, Interleukin-2. Promising and less promising compounds were distinguished. Effectiveness of compounds was based on the augmentation of NK cell activity as well as the number of responding subjects. To conclude the assay is robust, reliable and can be used for functional screening of natural compounds modulating NK cell activity.
Microgrids are an increasingly common component of the evolving electricity grids with the potential to improve local reliability, reduce costs, and increase penetration rates for distributed renewable generation. The additional complexity of microgrids often leads to increased investment costs, creating a barrier for widespread adoption. These costs may result directly from specific needs for islanding detection, protection systems and power quality assurance that would otherwise be avoided in simpler system configurations. However, microgrids also facilitate additional value streams that may make up for their increased costs and improve the economic viability of microgrid deployment. This paper analyses the literature currently available on research relevant to value streams occurring in microgrids that may contribute to offset the increased investment costs. A review on research related to specific microgrid requirements is also presented.