batterydata/paper-abstracts huggingface dataset:
In the recent times, pseudocapacitive electrode materials have received great attention due to their considerable capability in storing ions at relatively fast charging rates. Among various candidates, niobium (V) pentoxide (Nb2O5) has gained much attraction for lithium-ion batteries (LIBs) due to its insertion/extraction reaction with Li, safe redox potential, and considerably good capacity (about 200 mAhg−1). Nevertheless, low conductivity of Nb2O5 has so far prevented its use as a viable electrode material for LIBs. In this study, we have successfully coated silver (Ag) nanoparticles (NPs) on the surface of one-dimensional orthorhombic Nb2O5 fiber (1D T-Nb2O5) using simple electrospinning processing. Ag NPs coated Nb2O5 fibers (Ag-1D T-Nb2O5) provided faster electron pathways, resulting in much improved capacity at a given current density with superior rate capabilities compared with pristine 1D T-Nb2O5. In addition, 1D T-Nb2O5 was more suitable for coating Ag NPs compared with T-Nb2O5 NPs, where its structural integrity was maintained even after cycling. As a result, effective coating of conductive Ag NPs on the 1D T-Nb2O5 resulted in excellent cycle retention characteristics (179.7 mAhg−1 after 500 cycles at 500 mA g−1) as well as superior rate capabilities (103.6 mAhg−1 at a current density of 5000 mA g−1).
The effect of Bi surface treatment on LiNi0.5Mn1.5−x Ti x O4 was examined. As a result, Bi surface film around 20nm thick was confirmed to be fabricated on the surface of 5V spinel LiNi0.5Mn1.5−x Ti x O4 by transmission electron microscopy (TEM) and energy dispersion X-ray spectrometer (EDX) analysis. The Bi compound was confirmed to be Bi2O3 by X-ray diffraction analysis. Cycle behavior was also found to be improved by Bi treatment. A retention capacity of up to around 85% was achieved after 500 cycles at 20°C, while a retention capacity as high as 70% was obtained after 500 cycles, even at 45°C. Storage performance was also improved with Bi treatment. Recovery capacity of more than 90% was obtained with Bi treatment after storage for 1 week at 60°C. The increased resistance in storage was also suppressed with Bi treatment, which would be due to the suppression of electrolyte decomposition by the Bi coating film. It was found that Bi treatment had the effect of decreasing the dissolution of Mn, Ni and Ti of the elements of the cathode active material, due to inductively coupled plasma (ICP) analysis. Based on these results, the Bi surface coating was found to have a remarkable effect on the improvement of the cells with 5V spinel.
The body of the new Porsche 911 is 7 % lighter than its predecessor. This is thanks to a further refined hybrid design using aluminum, steel, and composite materials. Despite the drop in weight, there is no loss of stability, rigidity and safety, which have even been strengthened in some areas compared to before. The company is using hybrid construction for an A-pillar for the very first time. The reinforcement with organic sheet, injection- molded ribs, and structural foam replaces the previous  reinforcement using high- tensile steel tubing. The A-pillar itself comprises higher- and maximum-strength sheet metal components made from e.g. boron steel. Except for the front apron and rear trim, the car's outer shell is all-aluminum. The sidewall of the coupé alone reduces the overall weight by around 12 kg. Besides high- tensile steel, greater use has been made of extruded aluminum profiles for the body shell, for example in the front and rear side members, inner and outer rocker panels and floor pan reinforcers. For the new 911, Porsche is also making increased use of die-cast aluminum components, for example in the front shock absorber mountings, rear tunnel casing and rear side members. One of the new joining techniques the company is using is friction welding with countersunk bolt heads to join together aluminum and steel. © Porsche
Silicon anode suffers from poor intrinsic conductivity and dramatic volume change during discharge/charge process, which hinders its commercialization for high energy density lithium-ion batteries. To address these challenges, silicon-sodium alginate-polyaniline composites are rationally designed and synthesized via in-situ polymerization. A hydrogen bond self-healing process occurs during lithiation and delithiation to accommodate the strong volumetric modification, so that the composites perform excellent electrochemical performance, with a capacity of 1099.5 mAh·g−1 after 200 cycles at the current density of 1.0 A·g−1. In view of the density functional theory calculations, the synergy effect of sodium alginate and polyaniline enhances the hydrogen bonding of the silicon and polymers, increases the electron transport capability, and results in excellent electrical, mechanical integrity and conductivity of the electrodes. Our work not only provides a facile procedure to prepare unique conducting three dimensional network structured composites as a commercial anode but also reveals the mechanism that the silicon nanoparticles avoids electrode pulverization via hydrogen bonding self-healing process.
Li x Ni1/3Mn2/3O2 (x > 2/3) compounds have been synthesized from P3 type Na2/3Ni1/3Mn2/3O2 precursor through a new reduction-ion exchange method. The XRD patterns of Li x Ni1/3Mn2/3O2 show superlattice peak around 2θ = 20°, which is similar to that of the lithium-excess manganese based cathode materials. In contrast to sample obtained from traditional ion exchange method, the Li x Ni1/3Mn2/3O2 compound delivers LiNi1/2Mn1/2O2–Li2MnO3 solid solution type potential profiles and higher capacity than that of Li2/3Ni1/3Mn2/3O2, especially for the capacity delivered in high potential region. Moreover, it exhibits extremely small irreversible capacity at the initial cycle and small capacity loss during cycling in the voltage range 4.7–2.5 V. The structure and electrochemical properties of metallic elements substituted Li x Ni2/9M1/9Mn2/3O2 (M = Al, Co, Fe, Mg) were also studied. XRD and Raman spectra results suggest that small amount substitution of Ni with other metal ions does not affect the main structure of Li x Ni2/9M1/9Mn2/3O2 compounds. For Mg substituted compound, Li x Ni2/9Mg1/9Mn2/3O2, it exhibits improved cycleability compared with the other samples.
A latent measure of white matter microstructure (gWM) provides a neural basis for information processing speed and intelligence in adults, but the temporal emergence of gWM during human development is unknown. We provide evidence that substantial variance in white matter microstructure is shared across a range of major tracts in the newborn brain. Based on diffusion MRI scans from 145 neonates [gestational age (GA) at birth range 23+2–41+5 weeks], the microstructural properties of eight major white matter tracts were calculated using probabilistic neighborhood tractography. Principal component analyses (PCAs) were carried out on the correlations between the eight tracts, separately for four tract-averaged water diffusion parameters: fractional anisotropy, and mean, radial and axial diffusivities. For all four parameters, PCAs revealed a single latent variable that explained around half of the variance across all eight tracts, and all tracts showed positive loadings. We considered the impact of early environment on general microstructural properties, by comparing term-born infants with preterm infants at term equivalent age. We found significant associations between GA at birth and the latent measure for each water diffusion measure; this effect was most apparent in projection and commissural fibers. These data show that a latent measure of white matter microstructure is present in very early life, well before myelination is widespread. Early exposure to extra-uterine life is associated with altered general properties of white matter microstructure, which could explain the high prevalence of cognitive impairment experienced by children born preterm.
LiNi x Co y Mn z O2 cathode materials play a vital role in next-generation lithium-ion batteries because of their high energy density, but they suffer capacity decay at elevated temperatures. Improving the cycling stability of LiNi x Co y Mn z O2 requires a basic comprehension of its capacity fade mechanisms. Here, we investigate the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 at 55 °C under various cutoff voltages and examine the corresponding degradation mechanisms. The discharge capacity of LiNi0.6Co0.2Mn0.2O2 increases from 176.0 mAh g−1 to 218.1 mAh g−1 at 1 C as the cutoff voltage increases from 4.3 V to 4.7 V, whereas the capacity retention decreases from 96.3% to 78.9% after 50 cycles, respectively. Ex situ analyses via high-resolution transmission electron microscopy illuminate structural transformations of cathode materials after electrochemical cycling. This accounts for the increase in charge transfer resistance and capacity loss. In addition, X-ray photoelectron spectroscopy analyses highlight the correlations between the electrochemical performance and interfacial compositions of the cathode/electrolyte interface. These data provide another explanation for the capacity degradation. Our results underscore the value of improving the surface structural stability of cathode materials and reducing the charge transfer resistance of the electrode/electrolyte interface.
Organic compounds can be used as electrode materials for Li-ion batteries, but problems such as facile dissolution and low electrical conductivity hinder their application. Here the authors report π-conjugated quinoxaline-based heteroaromatic molecules with multiple redox sites to tackle the problems.
The transcription factor Nrf2 regulates the basal and inducible expression of a battery of cytoprotective genes. Whereas numerous Nrf2-inducing small molecules have been reported, very few chemical inhibitors of Nrf2 have been identified to date. The quassinoid brusatol has recently been shown to inhibit Nrf2 and ameliorate chemoresistance in vitro and in vivo. Here, we show that brusatol provokes a rapid and transient depletion of Nrf2 protein, through a posttranscriptional mechanism, in mouse Hepa-1c1c7 hepatoma cells. Importantly, brusatol also inhibits Nrf2 in freshly isolated primary human hepatocytes. In keeping with its ability to inhibit Nrf2 signaling, brusatol sensitizes Hepa-1c1c7 cells to chemical stress provoked by 2,4-dinitrochlorobenzene, iodoacetamide, and N-acetyl-p-benzoquinone imine, the hepatotoxic metabolite of acetaminophen. The inhibitory effect of brusatol toward Nrf2 is shown to be independent of its repressor Keap1, the proteasomal and autophagic protein degradation systems, and protein kinase signaling pathways that are known to modulate Nrf2 activity, implying the involvement of a novel means of Nrf2 regulation. These findings substantiate brusatol as a useful experimental tool for the inhibition of Nrf2 signaling and highlight the potential for therapeutic inhibition of Nrf2 to alter the risk of adverse events by reducing the capacity of nontarget cells to buffer against chemical and oxidative insults. These data will inform a rational assessment of the risk:benefit ratio of inhibiting Nrf2 in relevant therapeutic contexts, which is essential if compounds such as brusatol are to be developed into efficacious and safe drugs.
Iron hydroxyl phosphate hydrate Fe1.19(PO4)(OH)0.57(H2O)0.43 (FPHH) was obtained by hydrothermal synthesis at 220°C for 6hours. Addition of carbon black to the solution before hydrothermal treatment led to a reduction of the FPHH particle size from ∼10μm in the carbon-free compound to ∼300–500nm in the FPHH-10%C and FPHH-20%C composite with a good dispersion of conducting carbon black. X-ray diffraction, 57Fe Mossbauer spectroscopy and a thermal decomposition study showed that the addition of carbon black did not interfere with the formation of the FPHH phase. Thanks to its favorable microstructural characteristics, the FPHH-10%C and FPHH-20%C material exhibited good performance as positive electrode for Li-ion battery, with high initial discharge capacities of 150, 128 and 112mAhg−1 at 0.25C, 0.5C and 1C rates respectively and 99% capacity retention after 150 cycles at 2C. These results show that addition of solid carbon directly into the solution prior to hydrothermal treatment is a simple and effective way to reduce particle size and also to improve electronic conductivity by dispersing conductive carbon around the active material. This approach is easily transferable to other compounds prepared by hydrothermal synthesis, in order to control particle size while retaining the advantage of crystallization at low temperature.
Sluggish reaction rate of [VO]2+/[VO2]+ redox couple is an obstacle to be addressed in vanadium redox flow battery (VRFB). To improve the slow reaction rate, Pt/C catalyst synthesized by polyol method is suggested. Its catalytic activity, reaction reversibility and charge–discharge performance are evaluated by half cell and single cell tests, while its crystal structure, particle size and particle distribution are measured by XRD and TEM. The XRD and TEM measurements show the polyol Pt/C catalyst has larger electrochemically active surface (EAS) area and smaller particle size than commercial Pt/C catalyst. When catalytic activities of all the catalysts are estimated, the Pt-included catalysts demonstrate high peak current ratio, small peak potential difference and high electron transfer rate constant, confirming that their catalytic activity and reaction reversibility are excellent. In charge–discharge performance tests, the catalysts indicate high efficiencies as well as low overpotential and internal resistance. Excellent performances of the Pt-included catalysts are attributed to positively charged Pts that serve as active sites for activating [VO]2+/[VO2]+ reaction. Indeed, adoption of the Pt-included catalysts, especially, use of the polyol Pt/C consisting of uniform and small particles helps improve performance of VRFB.
At room temperature, crystalline Mg-based alloys, including Mg2Ni, MgNi, REMg12 and La2Mg17, have been proved with weak electrochemical hydrogen storage performances. For improving their electrochemical property, the Mg is partially substituted by Ce in Mg–Ni-based alloys and the surface modification treatment is performed by mechanical coating Ni. Mechanical milling is utilized to synthesize the amorphous and nanocrystalline Mg1−xCexNi0.9Al0.1 (x = 0, 0.02, 0.04, 0.06, 0.08) + 50 wt%Ni hydrogen storage alloys. The effects made by Ce substitution and mechanical milling on the electrochemical hydrogen storage property and structure have been analyzed. It shows that the as-milled alloys electrochemically absorb and desorb hydrogen well at room temperature. The as-milled alloys, without any activation, can reach their maximal discharge capacities during first cycling. The maximal value of the 30-h-milled alloy depending on Ce content is 578.4 mAh/g, while that of the x = 0.08 alloy always grows when prolonging milling duration. The maximal discharge capacity augments from 337.4 to 521.2 mAh/g when milling duration grows from 5 to 30 h. The cycle stability grows with increasing Ce content and milling duration. Concretely, the S100 value augments from 55 to 82% for the alloy milled for 30 h with Ce content rising from 0 to 0.08 and from 66 to 82% when milling the x = 0.08 alloy mechanically from 5 to 30 h. The alloys’ electrochemical dynamics parameters were measured as well which have maximum values depending on Ce content and keep growing up with milling duration extending.
The identification and development of conductive electrolytes with high concentrations of redox active species is key to realizing energy-dense nonaqueous flow batteries. Herein, we explore the use of ether solvents (1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), diethylene glycol dimethyl ether (DEGDME), and tetraethylene glycol dimethyl ether (TEGDME)) as the basis for redox electrolytes containing a lithium ion supporting salt (LiBF4 or LiTFSI) and 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB) as an active material. An automated high-throughput platform is employed to screen various electrolyte compositions by measuring solution conductivity and solute solubility as a function of solvent and salt type, component concentration, and temperature. Subsequently, the electrochemical and transport properties of select redox electrolytes are characterized by cyclic voltammetry using glassy carbon disk electrodes and by linear sweep voltammetry using carbon fiber ultramicroelectrodes. In general, improvements in electrolyte conductivity and solute solubility are observed with ether-based formulations as compared to previously reported propylene carbonate (PC)-based formulations. In particular, the addition of DOL to a DME-based electrolyte increases the conductivity and decreases the temperature for solubilization at high LiTFSI and DBBB concentrations. The redox behavior of DBBB remains consistent across the range of concentrations tested while the diffusion coefficient scales with changes in solution viscosity.
Self-supported core/shell nanowire arrays are highly desirable for designing high-performance electrochemical energy storage devices. Herein, we report self-supported ternary core/shell nanowire arrays of Co3O4/NiO/C on the nickel foam with the help of hydrothermal synthesis, chemical bath deposition and annealing carbonation methods. As an anode material for lithium ion batteries, the Co3O4/NiO/C core/shell nanowire arrays exhibit excellent electrochemical performances with lower polarization, higher capacity, improved cycle life and better high-rate capability than the pure Co3O4 nanowire arrays and single NiO nanoflake arrays. The enhanced electrochemical properties are mainly ascribed to the core/shell nanowire architecture with potential synergistic contribution such as improved mechanical stability and enhanced conductivity as well as faster ion/electron transfer.
In this study, composite electrodes with hybrid formulation of graphene nanoplatelets and manganese oxide were fabricated. Graphene nanoplatelets modified with MnO2 particles under sonication in an organic solvent. The produced solution was utilized to form film electrodes on aluminum substrate and also to wet carbon fiber cloth in order to form multifunctional structural composite with energy storage ability. The morphology of the graphene nanoplatelet/manganese oxide electrodes was characterized by Scanning Electron Microscopy and Raman spectroscopy. Quasi solid-state electrolytes, consisted of different % wt. loadings of succinonitrile (SN), ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF4) and copolymer poly vinylidenefluoride-hexafluoropropylene (PVDF-HFP), were prepared to be utilized as ionic conductors for the formation of supercapacitors. Differential scanning calorimetry (DSC) was used to characterize the thermal stability of the electrolytes. DSC studies confirmed that polymer electrolytes remain stable in the same phase over a wide temperature range of -40 to 140 °C. Also, mixture of epoxy and the quasi-solid polymer electrolyte was prepared to form a solid polymer electrolyte with higher stiffness. The electrochemical performance of the supercapacitor electrodes was evaluated by cyclic voltammetry, charge/discharge and impedance spectroscopy. The maximum value of specific capacitance achieved for the film electrodes was ˜450 F/g and for semi-solid and solid polymer electrolyte was ˜165 F/g and ˜15 F/g respectively. Finally, tensile tests performed at ambient conditions to determine the mechanical behavior of the supercapacitors. The results of this study are very promising for the development of materials with high combined performance in the field multifunctional composite structural materials with energy storage capabilities and can applied in a variety of industries such automotive, aerospace and wearable electronics.
Well-defined TiO2 nanotube size gradient thin films, manufactured using a bipolar electrochemistry approach, can be used as versatile monolithic hybrid electrodes for energy storage devices. The nanotube size distribution within the gradients can readily be controlled by altering the bipolar current and/or the length of the bipolar titanium sheet. As the electrochemical properties of the gradient electrodes can be carefully tailored by modifying the nanotube size gradient, this approach provides new possibilities for the manufacturing of hybrid electrodes with integrated energy and power density gradients. The free-standing anatase TiO2 nanotube size gradient electrodes provide unprecedented capacities at cycling rates from C/5 (i.e. 162μAhcm−2 or 169mAhg−1) to 50C (i.e. 40μAhcm−2 or 42mAhg−1). It is likewise shown that the size gradient electrodes facilitate fundamental studies of the charge/discharge process of TiO2 based electrodes. The results demonstrate that the different shapes of charge and discharge curves of TiO2 nanotube electrode can be explained by inherent differences between the lithiation and delithiation processes.
ac impedance and electrochemical quartz crystal microbalance (EQCM) techniques have been applied to analyze the structure of electric double-layer formed at carbon/organic electrolyte solution interface using a sputtered carbon electrode. The mass changes caused by electrochemical adsorption (accumulation) of ions have been estimated in the solutions of propylene carbonate (PC) dissolving tetrafluoroborate (BF4 −) salts of lithium (Li+), tetraethylammonium (TEA+) and tetra-n-butylammonium (TBA+) cations. The observed mass changes during the cathodic polarization in the solutions containing TEA+ and TBA+ were well consistent with those expected by the calculation based on mono-layer adsorption of the cations with giving the consideration to the surface roughness. On the other hand, the mass change observed in the solution containing Li+ salt showed that the solvation of Li+ with three or four molecules of PC would be the charge compensation species at the interface. Comparison of the quantity of the electricity passed during the EQCM measurements with that from theoretical calculation with simple Helmholtz-layer model revealed that the major part of the double-layer capacitance would be based on the electrostatic polarization of the solvent molecule directly adsorbed at the carbon surface.
With large scale battery systems being more and more used in demanding applications regarding lifetime, performance and safety, it is of great importance to utilize not only cells with a high cyclic and calendric lifetime but also to optimize the whole system architecture. The aim of this work is therefore, to highlight the benefits of a modular system architecture allowing the use of hybrid battery systems combining high power and high energy cells in a multi-technology system. To achieve an optimized performance, efficiency and lifetime for an electric vehicle the complete drive train topology has to be taken into account instead of optimizing one of the components individually. Consequently, the topic will be analyzed from the system’s point of view, addressing in particular the modularization of the battery as well as the power electronics needed to do so. It will be shown that a highly flexible battery system can be realized by dc-to-dc converters between a modular, hybrid battery system and the drive inverter. By the dc-to-dc converters the battery output voltages and the inverter input voltages are decoupled. Hence, the battery’s topology can be chosen unrestrictedly within a wide range and easily be interconnected to a common dc-link of a different voltage. The benefits of this flexibility will be analyzed in detail showing especially how the lifetime of the battery system can be improved and the impact on system weight.