batterydata/paper-abstracts huggingface dataset:
Isothermal, physics-based cell sandwich model has been validated with experimental galvanostatic discharge data at various current densities for advanced lithium-ion cells. The overpotential is higher at higher current densities and mostly increases with discharge at any given rate. The various contributions to cell overpotential during galvanostatic discharge at 5C and 3C constant-current densities are quantified in detail and analyzed. This work will aid in research and development efforts to mitigate these limitations for better cell performance in potential advanced electric vehicle applications.
Electrochemically formed solid electrolyte interfaces (SEIs) are the crucial link between electrolytes and electrodes because they enable several functions in lithium ion batteries, including ionic diffusion, electric conduction, and the safety provided by thermal stability. However, fabricating the electrochemical formed in SEI entails accuracy regarding its architecture to create the specific electrolyte composition that is mutually compatible with the electrode materials. This process, however, is difficult and hinders the industrial application and development of lithium ion batteries. In this study, the atomic layer deposition (ALD) technique is used in artificial SEI fabrication to deposit a metal oxide on the graphite anode's surface. In addition, the effects of the artificial SEI-applied Al2O3 and TiO2 on the charge–discharge performance and cycling behavior at 55 °C were investigated. Electrochemical performance was analyzed by an impedance and cyclic voltammogram to show that an ALD coating of TiO2 provides crucial functions for graphite. The results indicated that the TiO2 coating increased the graphite capacity by 5% and limited the formation of electrochemically formed SEIs. In addition, the TiO2-coating graphite with ALD improved thermal stability and greatly enhanced long-term cycle ability at 55 °C.
Publisher Summary Modern ceramics are a very diverse group of materials with widely varying physical properties that can be adapted to many technological needs. The basic science of advanced ceramics is approached in three steps. First, the major classes of ceramic materials are introduced and their crystal structures and crystal chemistry described. Then, the various models for chemical bonding in ceramic compounds are briefly outlined. The third step is to relate physical properties to crystal chemistry and crystal structure. The properties depend on crystal structure, on the electronic structure of the individual ions that make up the structure, and on the chemical bonding within the structure. Structures are determined in large part by ratios of the atomic constituents and by ionic radii. Bonding is a function of the collective interaction (or lack of interaction) of the outer-shell electrons with each other. There are three main models that can be applied to chemical bonds in ceramics and each has its own theoretical structure. These are the classical electrostatic model, augmented by crystal field theory, for ionic compounds; the molecular orbital model for covalent compounds; and the band model for semiconductors and metals.
We have examined the evolution of the oxidation state and atomic structure of vanadium(V) in discharged and charged nanophase vanadium pentoxide (V2O5) aerogel cathodes under in situ conditions using X-ray absorption spectroscopy (XAS). We show that the oxidation state of V in V2O5 aerogel cathode heated under vacuum (100 μTorr) at 220°C for 20.5 h is similar to that of V in a commercially obtained sample of orthorhombic V2O5. In addition, lithium (Li) insertion during the first cycle of discharging leads to the reduction of V(V) to V(IV) and V(IV) to V(III) in a manner consistent with the stoichiometry of the sample (i.e. Li x V2O5). Li extraction during charging leads to oxidation of V(III) to V(IV) and then V(IV) to V(V). Furthermore, the oxidation state of V in fully charged cathodes remains unchanged with cycling (upto at least the 16th cycle) from that of V in the control V2O5 aerogel cathode. However, the average oxidation state of V in discharged V2O5 cathodes increased with cycling. Moreover, the local structure of V in the discharged state has a higher degree of symmetry than that of the fully charged state. A significant change in the structure of the VV correlation of discharged cathodes is observed with cycling indicating the formation of electrochemically irreversible phases.
Nano-sized SiO x /C composite with core–shell structure is prepared by a modified Stöber method. After heat-treatment, the O/Si ratio in SiO x /C composite is near 1 and the core of SiO x presents a structure composing of amorphous Si clusters and ordered SiO2 domains. SiO x /C composite anode shows high specific capacity (ca. 800mAhg−1), excellent cycling stability, good rate-capability but low initial coulombic efficiency. Li2O and Li4SiO4 may generate in the initial lithiation process, which, combining with the carbon shell, can buffer the volume change caused by the alloying of Si with Li, and thereby improving the cycling stability of electrode. The nano feature of SiO x /C particle and the electronic conductive nature of carbon coating layer ensure the good rate-capability of SiO x /C electrode.
The purpose of this study was to compare the prevalence of overweight and obesity in typically developing (TD) children, children with developmental coordination disorder (DCD) and balance problems (DCD-BP), and children with DCD without balance problems (DCD-NBP). Two thousand and fifty-seven children (1095 boys, 962 girls) ages 9–12 years were recruited from 18 elementary schools in Taiwan. The Movement Assessment Battery for Children was used to assess motor coordination ability. International cut-off points for body mass index were used to classify participants into the following groups: normal-weight, overweight or obese. Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR=2.28; 95% CI=1.41–3.68). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR=1.79; 95% CI=1.02–3.16). Boys in the DCD-BP group were more likely to be obese when compared to DCD-BP girls (OR=3.12; 95% CI=1.28–7.57). Similarly, DCD-NBP boys were more likely to be obese when compared to DCD-NBP girls (OR=2.67; 95% CI=1.21–5.89). Children with both DCD and BP were significantly more likely to be obese when compared to TD and DCD-NBP children. From an intervention perspective, the inclusion of regular physical activity, including activities that encourage development of both balance and energy expenditure, may be required to prevent obesity in this population.
Cognition, memory, and attention and arousal have been linked to nicotinic acetylcholine receptors (nAChRs). Thus it is not surprising that nAChRs have been strongly implicated as therapeutic targets for treating cognitive deficits in disorders such as schizophrenia and Alzheimer's disease (AD). In particular the alpha7 (α7) nAChR has been closely linked with normalization of P50 auditory evoked potential (AEP) gating deficits, and to a lesser extent improvements in pre-pulse inhibition (PPI) of the acoustic startle response. These two brain phenomena can be considered as pre-attentive, occurring while sensory information is being processed, and are important endophenotypes in schizophrenia with deficits likely contributing to the cognitive fragmentation associated with the disease. In addition α7 nAChRs have been implicated in attention, in particular under high attentional demand, and in more demanding working memory tasks such as long delays in delayed matching tasks. Efficacy of α7 nAChR agonists across a range of cognitive processes ranging from pre-attentive to attentive states and working and recognition memory provides a solid basis for their pro-cognitive effects. This review will focus on the recent work highlighting the role of α7 in cognition and cognitive processes.
Sodium-ion batteries are a cost-effective alternative to lithium-ion for large-scale energy storage. Here Bao et al. develop a cathode based on biomass-derived ionic crystals that enables a four-sodium ion storage mechanism leading to exceptionally high specific capacity and energy density.
Owing to their solution processability, unique two-dimensional structure, and functionalization-induced tunable electronic structures, graphene oxide (GO) and its derivatives have been used as a new class of efficient hole- and electron-extraction materials in polymer solar cells (PSCs). Highly efficient and stable PSCs have been fabricated with GO and its derivatives as hole- and/or electron-extraction layers. In this review, we summarize recent progress in this emerging research field. We also present some rational concepts for the design and development of the GO-based hole- or electron-extraction layers for high-performance PSCs, along with challenges and perspectives.
Multiple epidemiological data showed a significant higher prevalence of hypovitaminosis D in patients with Parkinson’s disease (PD).
This work aims to evaluate the average turn-over frequency of O2 electro-reduction for the catalytic sites resulting from the heat-treatment of iron- or cobalt-acetate and carbon black in ammonia at high temperature. This task is complex because at least three factors may control the activity of such catalysts: their metal content, nitrogen content and micropore specific area. In this work, the activity was measured for metal contents from 0.005 to 5wt.%. The time of heat-treatment was tuned to keep the micropore specific area constant. At Fe content ≤0.2wt.% the activity increases linearly with Fe content, thus enabling the average turn-over frequency of the Fe/N/C site to be determined. At Co content ≤1.0wt.% the activity increases approximately as the square root of the Co content. Because no linear relation was found, the turn-over frequency of the Co/N/C site could not be determined. For both Fe and Co catalysts, the activity drops dramatically at contents >1wt.%. This is concurrent with a drop in the micropore specific area of the catalysts.
The authors report that neddylation is required for dendritic spine development and stability, and loss of neddylation in excitatory forebrain neurons leads to synaptic loss, impaired neurotransmission, and learning and memory deficits. The roles of neddylation in spine maturation and synaptic transmission could be attributed to neddylation of PSD-95.
High-performance ZnO microspheres doped and coated with carbon has been successfully fabricated by a facile three-step process using trisodium citrate as doping carbon source and glucose as coating carbon source. Compared with carbon free ZnO precursor, the resulting ZnO-N2@Cmicrospheresexhibitsuperiorrateperformanceandenhancedcyclingstability.(*) At a rate of 10C (5000mAg−1), the ZnO-N2@C exhibits specific discharge capacity and volumetric capacities of 283.4mAhg−1 and 858.7mAhcm−3, respectively, while the values for the carbon free ZnO precursor are only 140.2mAhg−1 and 423.4mAhcm−3. After cycling 200 times at 500mAg−1, the obtained ZnO-N2@C can maintain a satisfying capacity of 508.2mAhg−1, corresponding to a superior capacity retention (94.7%). In contrast, carbon free ZnO can only deliver the capacity of 109.4mAhg−1 and a capacity retention of 24.7% after 200 cycles. This outstanding improvement is attributed to the synergistic effect of the combined in-situ doping and coating carbon, including reduced charge-transfer resistance, enhanced electrochemical reversibility, and better anti-corrosion capabilities. As a result, it is believed that ZnO-N2@C should be an attractive and promising anode material for high power Zinc-Nickel batteries.
A novel composite nonwoven separator exhibiting high heat resistance, high ionic conductivity and high lithium ion transference number is fabricated by a simple dip-coating and heat treatment method. The thermal stable polyimide (PI) nonwoven matrix is chosen as a mechanical support and contributes to improving the thermal shrinkage of the composite nonwoven separator (abbreviated as IACS). The cross-linked poly(2-acrylamido-2-methylpropanesulfonic acid) PAMPS(Li+) gel polymer electrolyte (GPE), lithium ion sources of a single ion conductor, is introduced into the PI nonwoven matrix and acts as a functional filler. This PAMPS (Li+) GPE is proved to be able to provide internal short circuit protection, to alleviate liquid electrolyte leakage effectively, to supply more lithium ions dissociating from PAMPS (Li+) by liquid electrolyte solvent, to contribute a more stable interfacial resistance, and thus resulting in an excellent cyclability. More notably, the migration and mobility rate of anions could be hindered by the −SO3 − group in the PAMPS (Li+) polymer based on electrostatic interaction, giving rise to a very high lithium ion transference number. These fascinating characteristics endow the IACS a great promise for the application in the high power and high safety lithium ion batteries.
Graphenothermal Reduction process is used to obtain exfoliated graphene oxide (EG)/iron (II) oxide (FeO) composite prepared at 650 °C for 5 h in argon. Structural and compositional analyses of the sample confirm the formation of EG/FeO composite. This composite shows a reversible capacity of 857 mAh g−1 at a current rate of 50 mA g−1 in the voltage range 0.005–3.0 V versus Li. An excellent capacity retention up to 60 cycles and high coulombic efficiency of 98% are also observed. Characteristic Fe2+/0 redox peaks observed in Cyclic Voltammetry measurement are explained in correlation with lithium storage mechanism. Thermal, electrical and impedance spectroscopy studies of EG/FeO composite are discussed in detail. Comparative electrochemical cycling studies of EG/FeO composite with Fe2O3 and Fe3O4 materials prepared under controlled conditions are also discussed.
The separation of variables method is extended to obtain concentration profiles in a particle electrode under galvanostatic boundary conditions. The method is also used to find exact analytical solutions for composite slab and spherical electrodes. Finally, the method is used to obtain a solution for a lithium/polymer cell model that was presented previously by Doyle and Newman.
The influence of carbon black content and carbon black distribution on performance of oxide-based cathodes, such as LiCoO2 and LiMn2O4, is investigated. The electronic conductivity of oxide material/carbon black composites is compared with electrochemical characteristics of the same composites. Uniformity of carbon black distribution in cathode composites is achieved using novel coating technology in cathode preparation. In this technology, the active particles are first pretreated in a gelatin solution. The adsorbed gelatin then controls the deposition of carbon black so that carbon black particles are uniformly distributed in the final composite. The influence of various parameters, such as pH of gelatin, amount of gelatin and concentration of carbon black on the uniformity of carbon black distribution is investigated. It is shown that the conventional technology of cathode preparation yields quite non-uniform distribution of carbon black in cathode material. At the end, we demonstrate that uniformity of carbon black distribution has a crucial impact on reversible capacity, especially at high current densities.
As reported in the last issue of Membrane Technology, the Fuel Cell Seminar – held in San Antonio, Texas in early November – provided California-based PolyFuel Inc with an opportunity to demonstrate the capabilities of its direct methanol fuel cell membranes. Here we provide details of a contest that was run in real time by the company, to compare its hydrocarbon-based fuel-cell materials with DuPont's widely used, fluorocarbon-based Nafion 117 membranes.
In this work, novel core-shell structured Fe3O4@NiS nanocomposites with different NiS: Fe3O4 mass ratios, namely x wt.% Fe3O4@NiS, have been successfully synthesized by a modified sedimentation-oxygenation method, in which the NiS outer layer (∼4nm) in-situ grown on the surface of Fe3O4 nanoparticles (∼30nm). For comparison propose, pure Fe3O4 as well as NiS ex-situ modified Fe3O4 composites (x wt.% Fe3O4/NiS) are also prepared and studied. When evaluated the electrochemical properties as anode material, all of the Fe3O4@NiS nanocomposites exhibit much better performance than pristine Fe3O4 material, due to the inhibition effect of NiS layer for retarding the generation of Fe(OH)2 passivation layer, which inevitably generates in the discharge process of the electrode and will hinder the OH− getting deeper into the active particles for further electrochemical reactions. Contrast to Fe3O4/NiS, Fe3O4@NiS nanocomposites also display better electrochemical properties owing to their relatively completer and more uniform NiS coating layer. In view of the advantages of the designed in-situ nano core-shell structure as the facile controlled synthesis process and low cost of the raw materials, it is believed the environment-friendly and high-performance Fe3O4@NiS nanocomposite is a promising type of anode candidate material for iron-based alkaline rechargeable batteries.
Casein from bovine milk is evaluated in this work as binding agent for electrochemical double layer capacitors (EDLCs) electrodes. It is demonstrated that casein provides excellent adhesion strength to the current collector (1187 kPa compared to 51 kPa achieved with PVdF), thus leading to mechanically stable electrodes. At the same time, it offers high thermal stability (above 200 °C) and electrochemical stability in organic electrolytes. Apparently though, the casein-based electrodes offer lower electronic conductivity than those based on other state-of-the-art binders, which can limit the rate performance of the resulting EDLC. In the attempt of improving the electrochemical performance, it is found that the application of a pressing step can solve this issue, leading to excellent rate capability (up to 84% capacitance retention at 50 mA cm−2) and cycling stability (96.8% after 10,000 cycles at 10 mA cm−2) in both PC- and ACN-based electrolytes. Although the adhesive power casein is known since ancient times, this report presents the first proof of concept of its employment in electrochemical power sources.
The performances of electrodialysis (ED) and reverse electrodialysis (RED) processes depend on several factors, including the nature of the electrode material and of the redox couple adopted to make possible the conversion between electric power and chemical potential. In this paper, the possible utilization of iron-based redox couples (FeCl3/FeCl2, hexacyanoferrate(III)/hexacyanoferrate(II) and Fe(III)-EDTA/Fe(II)-EDTA) on graphite and DSA electrodes for RED processes was studied by a detailed experimental investigation. The hexacyanoferrate(III)/hexacyanoferrate(II) system was stable for long time (more than 12days) in the absence of light and oxygen at high redox couple concentrations and low current densities both at compact graphite and DSA electrodes. Perfluorinated Nafion cationic membranes were found to be impermeable to the components of the redox couple. Fe(II)-EDTA exhibited a limited electrochemical stability in long term electrolyses at all adopted operative conditions, which discourages the use of the Fe(III)-EDTA/Fe(II)-EDTA for RED applications. The FeCl3/FeCl2 system was, on the other hand, stable for long times (more than 12days) at acidic pH at compact graphite electrodes. Selemion anionic membranes allowed to confine the redox couple in the electrode compartments with very slow passage of protons to the side compartment (“dilute or concentrated compartment”).
Mixed-phase iron oxide nanocomposites (abbreviated as m-Fe2O3) of hematite (α-Fe2O3) and magnetite (γ-Fe2O3), using potassium ferricyanide (K3[Fe(CN)6]) as the precursor, are successfully synthesized via a simple two-step approach incorporating a hydrothermal reaction and the subsequent thermal annealing. The crystalline structures, specific surface areas and surface morphologies of the as-prepared m-Fe2O3 are characterized in detail by X-ray diffraction (XRD), nitrogen sorption analysis and scanning electron microscopy (SEM), respectively. The electrochemical performances of m-Fe2O3 are examined by galvanostatic cycling and cyclic voltammetry (CV). Transmission electron microscope (TEM), High resolution TEM (HRTEM), selected area electron diffraction (SAED) and Raman are used to investigate the nanocrystalline and composition of the materials. Compared to α-Fe2O3, m-Fe2O3 exhibits a much more excellent cycling stability with a typical discharge specific capacity of 982 mAh g−1 after 50 cycles at a current density of 100 mA g−1, which is attributed to α-Fe2O3 converted to γ-Fe2O3 during charge–discharge cycling. The superior performance of m-Fe2O3 to α-Fe2O3 would provide a new perspective about the effect of mixed-phase on improving the electrochemical properties of lithium-ion batteries.
Silicon negative electrode for lithium ion battery was designed in the form of self-organized 1D core-shell nanotubes to overcome shortcomings linked to silicon volume expansion upon lithiation/delithiation typically occurring with Si nanoparticles. The negative electrode was formed on TiO2 nanotubes in two step electrochemical synthesis by means of anodizing of titanium and electrodeposition of silicon using ionic liquid electrolytes. Remarkably, it was found that the silicon grows perpendicularly to the z-axis of nanotube and therefore its thickness can be precisely controlled by the charge passed in the electrochemical protocol. Deposited silicon creates a continuous Si network on TiO2 nanotubes without grain boundaries and particle-particle interfaces, defining its electrochemical characteristics under battery testing. In the core-shell system the titania nanotube play a role of volume expansion stabilizer framework holding the nanostructured silicon upon lithiation/delithiation. The nature of Si shell and presence of titania core determine stable performance as negative electrode tested in half cell of CR2032 coin cell battery.
Amyotrophic lateral sclerosis (ALS) is an incurable progressive paralytic motor neuron disease with limited therapeutic options. Since their creation by Gurney et al. (1994) [Science 264:1772–1775], transgenic superoxide dismutase-1 with glycine to alanine switch at codon 93 (SOD1G93A) mice have become the benchmark pre-clinical model for screening ALS therapies. Surprisingly, despite physiological, anatomical, ultrastructural and biochemical evidence of early motor system dysfunction, it has proven difficult to detect motor performance deficits in pre-symptomatic SOD1G93A mice. As an alternative to conventional forced motor tests, we investigated the progression of motor performance deficits in freely behaving pre-symptomatic congenic B6.SOD1G93A mice. We found that motor performance deficits began several weeks prior to the onset of overt clinical symptoms (postnatal day 45). More importantly, once motor performance deficits manifested, they persisted in parallel with disease progression. In addition, two physical measures of muscle girth revealed progressive hindlimb muscle atrophy that predicted genotype in individual pre-symptomatic mice with 80% accuracy. Together, these data suggest that muscle girth is a reliable and indirect measure of hindlimb muscle denervation and an early, objective marker for disease onset in congenic B6.SOD1G93A ALS mice. Moreover, we present regression equations based on hindlimb muscle girth for predicting genotype in future studies using B6.SOD1G93A mice. These findings support new objective criteria for clinical disease onset and provide objective measures that require little expertise. These studies demonstrate a cost-effective approach for more thorough evaluation of neuroprotective strategies that seek to disrupt disease mechanisms early in the disease process. To our knowledge, these findings are the first to report early chronic motor performance and physical deficits that are coincident with the earliest known motor dysfunction in any ALS mouse model.