batterydata/paper-abstracts huggingface dataset:
A set of experiments were carried out at reduced and elevated temperatures (−10, −5, 0, 20, 50, 60 and 70 °C) to investigate the homogeneity of lithium-ion batteries under abusive temperature environment in combination with different cycle rates (1C, 2C, 3C and 4C). Based on the experimental results, we found that the surface temperature of battery increased gradually along the axial direction from anode to cathode indicating the position closer to cathode possessed larger internal resistance, therefore had larger heat generation. The homogeneity of battery deteriorated under large cycle rate exhibited as severer temperature rise and temperature difference. In addition, it was also found that the homogeneity of battery would be worse under abusive temperature environment by aggravating temperature rise, temperature difference and voltage difference. Compared to high temperature environment, low temperature environment would cause severer homogeneity. Moreover, the severity was exacerbated with the aggravation of abusive environment.
Objective The present study evaluates the potential relationship between hippocampal atrophy and EEG brain rhythmicity, as assessed by relative band power and alpha frequency indices in a cohort of subjects with mild cognitive impairment (MCI). Methods Eighty-eight subjects falling within the definition of MCI patients were enrolled. All subjects underwent EEG recording and magnetic resonance imaging (MRI). Volumetric morphometry estimates of the hippocampal region were computed. Individual EEG frequencies were indexed by the theta/alpha transition frequency (TF) and the individual alpha frequency (IAF). The relative power was separately computed for delta, theta, alpha1, alpha2 and alpha3 frequency bands. The MCI cohort was classified into four subgroups, based on the mean and standard deviations of the hippocampal volume of a normal elderly control sample. Results The group with moderate hippocampal atrophy showed the highest increase in the theta power on frontal regions, and of the alpha2 and alpha3 powers on frontal and temporo-parietal areas. The analysis of the individual alpha frequency markers showed that the values for the alpha markers were highest in the group with the smallest hippocampal volume, whereas in the group with moderate hippocampal atrophy, these values were lower than in the group with severe atrophy. Conclusions The relationship between hippocampal atrophy and EEG activity changes in MCI subjects is not proportional to the hippocampal atrophy. Therefore, EEG markers could represent a new tool for differential diagnosis. Significance The hippocampal atrophy induces different brain synchronization/desynchronization patterns. EEG changes model the brain activity induced by a discrete change of the hippocampal volume. The changes in the EEG rhythmicity differ greatly from those in MCI patients with subcortical vascular damage.
Semi-interpenetrated network Solid Polymer Electrolytes (SPEs) were fabricated by UV-induced cross-linking of poly(ethyleneglycol) diacrylate (PEGDA) and divinylbenzene (DVB) within a poly(ethyleneoxide) (PEO) matrix (Mv =5×106 gmol−1), comprising lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI), at a molar ratio of EO:Li ∼30:1. The influence of the DVB content on the final SPE properties was investigated in detail. An increase of DVB concentration resulted in self-standing polymer electrolytes. The DVB cross-linker incorporation was found to decrease the crystallinity of the PEO matrix from 34% to 23%, with a decrease in the melting temperature (Tm) of the membrane from 50°C to 34°C. Moreover, the influence of the DVB concentration on the ionic conductivity was determined for polymer electrolytes with 0, 10, 20 and 45% DVB from room temperature (RT) to 80°C. The resulting SPEs showed a high electrochemical stability of 4.3V as well as practical conductivity values exceeding 10−4 Scm−1 at 70°C. Cycling performance of these semi-interpenetrated SPE’s have been shown with a Li metal polymer battery and all solid -state Li sulphur battery.
Microscale C-Li4Ti5O12 particles with high tap density were synthesized by a simple solid-state reaction using TiO2, Li2CO3, and pitch. The effect of the carbon content on the physicochemical and electrochemical properties of this material was extensively studied. On calcination of the particles at high temperature in an inert atmosphere, the uniformly coated carbon layer from pitch inhibited the growth of primary particles, maintaining the spherical morphology, similar to the TiO2 precursor in size and shape, and also enabling partial reduction of the starting Ti4+ to Ti3+. Excellent electronic conductivity of the C-coated Li4Ti5O12 resulted from the presence of the highly conducting carbon coating layer and the mixed valence state of Ti3+ and Ti4+. Both the nanoporous morphology and highly conducting carbon coating layer in Li4Ti5O12 particles gave rise to ultra high rate capability.
Stable hybrid silica decorated carbon composite is realized for improving oxygen reduction kinetics, performance and stability of polymer electrolyte fuel cell. Synthesis of platinum on an optimum level of silica decorated into carbon via single-step polyol method with minimum loading of platinum (0.15 mg cm−2) shows superior power density of 1.45 W cm−2 in relation to platinum on carbon. The optimum composition of silica decorated carbon preserves 70% of the electrochemical active surface area of platinum even after 6000 cycles from 1 to 1.5 V. The water retention ability for silica is responsible for maintaining the humidity within the triple phase boundary of the membrane electrode assembly, which in turn increases the fuel cell performance and stability even up to 100 h under low humidity. Besides, air-cooled prototype 15 cell stack is assembled comprising the above electrocatalyst which exhibits the power output of 100 W at 10 V under 40% relative humidity.
Utilization of plug-in electric vehicles (PEVs) in residential feeders is gaining popularity in recent years due to the societal awareness about greenhouse gas emission and the increasing of petrol price. The potential for network stress and congestion due to uncoordinated charging of PEVs is significant as they represent sizeable unbalanced loads with unpredictable locations, plug-in times, charging rates and durations. This paper aims to mitigate the detrimental impacts of electric vehicle charging on smart grid by implementing a decentralized coordinated PEV charging algorithm that will also improve the power quality of smart grid. The idea for the individual PEV chargers is to acquire distribution transformer loading through the smart meters to dynamically coordinate their charging times, rates and durations in order to improve the overall system voltage profile, reduce transformer stress and control current imbalance. Simulation results will be generated and analysed for an unbalanced three-phase 62 node residential network populated with PEV chargers using the Simulink-Matlab software.
Design and constructing hierarchical architecture nanostructure is very effective to achieve good electrochemical performance for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, uniform hierarchical Fe7S8 nanostructures coated by thin carbon layer (Fe7S8/C) have been prepared by a facile Polyvinylpyrrolidone (PVP) assisting hydrothermal method and heat treatment. PVP is acting dual function as both a surfactant for self-assembly of the secondary structure, and also providing porous carbon layers equably coating on Fe7S8 nanostructures after annealing process. Benefiting from the well-designed structure, a high reversible capacity of 751mAhg−1 over 100 cycles at 100mAg−1 is delivered for LIBs, and it also manifests superior sodium ion storage properties with a capacity of 497mAhg−1 after 100 cycles at 100mAg−1. The remarkable electrochemical performance of the Fe7S8/C composite implies the great potential as high capacity anode for next generation energy storage.
Precious metals are efficient oxygen electrocatalysts but suffer from poor stability and high cost. Now, nitrogen-doped carbon nanotubes derived from metal–organic frameworks are shown to have activity and durability comparable to that of Pt/C catalysts.
We report an aqueous lithium–sulfur battery based on aqueous dissolved Li2S4/Li2S redox couple as the cathode, metallic lithium as the anode and Li1.35Ti1.75Al0.25P2.7Si0.3O12 (LATP) as the separator. A reversible specific capacity of up to 1030 mA h g−1 is attained. Moreover, aqueous lithium–polysulfide batteries have a discharge potential of 2.53 V versus Li+/Li.
Lithium-ion cells for satellite applications operate under a special condition, and are expected to behave differently from those for commercial purposes. To understand the performance-degradation mechanism of lithium-ion cells experienced cycle-life testing in a simulated low-Earth-orbit (LEO) satellite operation, we conducted the structure analysis and surface characterization of the aged LiCoO2 cathode and graphite anode obtained from a lithium-ion cell with 4350-cycle LEO simulation experience. The analysis results were compared with a fresh cell which served as control. This paper provides a review of testing results on electrochemical and structure analysis. The capacity-verification and impedance measure results indicated that the LiCoO2 cathode, rather than graphite anode, was responsible for the performance degradation of the aged cell. This conclusion was confirmed by the structure analysis. The qualitative analysis of the XRD spectra disclosed that the aged cathode exhibited a much larger structure change than the aged anode. We also detected the lithium ions that were irreversibly reserved in graphite anode in XRD and 7Li nuclear magnetic resonance (NMR) analysis of aged graphite anode. These results lead us to deduce that the serious structure change in LiCoO2 cathode was primarily responsible for the performance degradation of the aged cell.
Dendritic growth of the metallic lithium anode cannot be fully avoided for prolonged cycling due to the inherent thermodynamic and kinetic tendency, which causes serious safety issues. Here, we strategically control the lithium metal growth direction by designing a three-dimensional porous host with lithiophilic-lithiophobic characterized ligaments. Therefore, lithium metal can only nucleate on the lithiophilic back surface and grow toward the direction away from the separator. Such ‘backside-growth’ can ensure safe battery operation even when lithium dendrites exist. For a proof-of-concept study, highly lithiophilic gold layer is sputtered on backside surface of each copper foam ligament. During lithium plating, lithium nucleates on the lithiophilic backside and keeps growing conformably from the existing nuclei towards the opposite direction to the separator, and eventually forms a lithium-metal layer with highly compacted self-aligned columnar structure. The novel approach controls lithium deposition in two aspects simultaneously: growth direction and morphology. Notably, the featured surface dendrite-free anode exhibits ultra-long-term stable cycling with a high Coulombic efficiency (e.g., 95.0% after 300 cycles, 0.5 mA cm−2, 1 mA h cm−2). This work may not only pave ways for building ultimate safe lithium batteries but also conceptually provides new opportunities for other metal anodes.
Conventional production of hydrogen requires large industrial plants to minimize energy losses and capital costs associated with steam reforming, water–gas shift, product separation and compression. Here we present a protonic membrane reformer (PMR) that produces high-purity hydrogen from steam methane reforming in a single-stage process with near-zero energy loss. We use a BaZrO3-based proton-conducting electrolyte deposited as a dense film on a porous Ni composite electrode with dual function as a reforming catalyst. At 800 °C, we achieve full methane conversion by removing 99% of the formed hydrogen, which is simultaneously compressed electrochemically up to 50 bar. A thermally balanced operation regime is achieved by coupling several thermo-chemical processes. Modelling of a small-scale (10 kg H2 day−1) hydrogen plant reveals an overall energy efficiency of >87%. The results suggest that future declining electricity prices could make PMRs a competitive alternative for industrial-scale hydrogen plants integrating CO2 capture.
We address the control of a residential energy storage system under dynamic pricing, for scenarios with and without local electricity generation, by combining a dynamic programming approach with real-time correction of predictions of load and generated power. We performed simulations using energy generation and consumption data for 64 residences in the Pecan Street Project, and a range of seasonal dynamic price tables. Our algorithm was more effective than other approaches in reducing electricity costs under most tariffs, especially when the amount of electricity generated locally is small.
The microporous layer (MPL) in polymer electrolyte fuel cells is known to enhance performance and durability of the membrane electrode assembly. However, its key structural parameters and transport properties are difficult to determine due to the lack of MPL-specific measurement techniques. The present work aims to establish a specialized framework for 3-D image based morphological characterization of MPLs. The proposed framework features a tuned focused ion beam-scanning electron microscope (FIB-SEM) imaging technique and an in-house developed procedure for image processing and reconstruction of the true 3-D structure which is validated with measured porosimetry data for a pure MPL sample. The effects of FIB milling parameters are evaluated and tuned to prevent image bias and damage to the delicate MPL structure. The pore size distribution of the reconstructed MPL structure is determined using a novel algorithm based on 3-D Euclidian distance transform and the results are found to be in good agreement with the measured data. Three reconstructed domains containing the structural information are generated to account for directional and spatial heterogeneity of the material and utilized as numerical domains for calculation of key MPL material properties, namely effective diffusivity, tortuosity, and effective thermal conductivity. By comparing the obtained material properties in the through-plane and in-plane directions, the MPL material is determined to be isotropic.
Silicon carbide (SiC) family is generally regarded as electrochemical inactive in lithium ion batteries (LIBs) and only a few literatures focused on its cycling property. In this work, bead-curtain shaped SiC@SiO2core-shellnanowires(SiC@SiO2 -CSNWs) on graphite paper (GP) were fabricated by employing modified chemical vapor deposition method (CVD). After further hydrofluoric acid treatment, bare SiC nanowires (SiCNWs) on GP were also obtained for comparison. The as-prepared SiC@SiO2 -CSNWs and SiCNWs were directly used as working electrodes without addition of binder or electron conductive material, which exhibited high specific capacities and good cycling stabilities. This could be ascribed to the unique nanowire structure, effectively buffering volume changes upon repeated alloying and de-alloying. Comparatively, SiC@SiO2-CSNWs presented much better electrochemical properties. Intensive transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectra analysis revealed that the SiO2 shell effectively separate the direct contact between active SiC and electrolyte, thus suppressed the fast growth of solid electrolyte interface (SEI) film in repeated cycling and stabilized the structure of active material.
The Swallowing Quality-of-Life Questionnaire (SWAL-QoL) is considered the gold standard for assessing health-related QoL in oropharyngeal dysphagia. The Dutch translation (DSWAL-QoL) and its adjusted version (aDSWAL-QoL) have been validated using classical test theory (CTT). However, these scales have not been tested against the Rasch measurement model, which is required to establish the structural validity and objectivity of the total scale and subscale scores. Thus, the purpose of this study was to examine the psychometric properties of these scales using item analysis according to the Rasch model.
Conductive carbon materials have been widely used as framework materials for electrodes. Spiral carbon nanotubes (SCNTs) with excellent physical and chemical properties can be used in lithium–sulfur (LiS) batteries. Here, a novel type of planar double-layer structure cathode was designed by introducing SCNTs. Sulfur, activated carbon (AC), and SCNTs were used to fabricate the S/AC/SCNT and S/AC/SCNT–AC planar double-layer structure cathodes. The initial discharge capacity of the batteries with the S/AC/SCNT and S/AC/SCNT–AC cathodes reached 1016 mAh g−1 and 946 mAh g−1 at 0.2 C, respectively. This result indicates that SCNTs play a major role given their excellent conductivity and insertion throughout the cathodes, which can provide an efficient charge transfer path for active materials. Moreover, the S/AC/SCNT–AC cathode exhibits long cycle stability with a capacity decay rate of only 0.11% per cycle at 0.5 C. Therefore, the introduction of SCNTs to a planar double-layer cathode is an efficient method for increasing the conductivity and bound polysulfide amount of LiS batteries.
The performance of an electrochemical double layer capacitor composed of activated carbon electrodes and 1-ethyl-3-methylimidazolium thiocyanate ([EMIm]SCN) as the electrolyte possessing extremely high conductivity and low viscosity, was investigated by cyclic voltammetry and galvanostatic charging/discharging. The effect of various factors governing the extraordinary performance of this capacitor in terms of its specific capacitance, current density, voltage and cycle-life, was examined in detail.
Nanostructured materials play an important role in advancing the electrochemical energy storage and conversion technologies such as lithium ion batteries and fuel cells, offering great promise to address the rapidly growing environmental concerns and the increasing global demand for energy. In this review, we summarize some of the recent progress and advances in our laboratory on nanostructured electrode materials for lithium ion batteries and platinum-based and platinum-free nanoalloy electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC). Materials design, novel chemical synthesis and processing, advanced materials characterization, and electrochemical evaluation data are presented.
Nanostructured metal oxides have received increasingly more attention due to their high specific surface area that may increase the active region of the material and hence enhance the performance of many electrochemical devices such as gas sensors or solid oxide fuel cells. However, it is still a major issue to keep these nanostructures stable at the high fabrication and operating temperatures of the electrochemical devices (e.g., solid oxide cells), typically over 1000°C and 700°C, respectively. In this work, thermally stable Ce0.8Sm0.2O1.9 mesoporous scaffolds were infiltrated with a Sm0.5Sr0.5CoO3-δ catalyst, which were then used as electrodes for solid oxide cells. The electrochemical properties of these nanocomposite electrodes in a symmetrical cell at 500–750°C were evaluated using electrochemical impedance spectroscopy. When tested at 700 °C for a long period of time, the cells showed no performance degradation but a 50 % reduction in the area specific resistance (ASR=0.08 Ω·cm2) after more than 200h of operation, suggesting that the mesoporous composites are promising electrodes for high-temperature electrochemical devices.
Locomotor activity of rodents is an important readout to assess well-being and physical health, and is pivotal for behavioral phenotyping. Measuring homecage-activity with standard and cost-effective optical methods in mice has become difficult, as modern housing conditions (e.g. individually ventilated cages, cage enrichment) do not allow constant, unobstructed, visual access. Resolving this issue either makes greater investments necessary, especially if several experiments will be run in parallel, or is at the animals’ expense. The purpose of this study is to provide an easy, yet satisfying solution for the behavioral biologist at novice makers level.
Lithium sodium titanate insertion-type anode has been synthesized by classical solid-state (dry) and an alternate solution-assisted (wet) sonochemical synthesis routes. Successful synthesis of the target compound has been realized using simple Na- and Li-hydroxide salts along with titania. In contrast to the previous reports, these energy-savvy synthesis routes can yield the final product by calcination at 650–750 °C for limited duration of 1–10 h. Owing to the restricted calcination duration (dry route for 1–2 h and wet route for 1–5 h), they yield homogeneous nanoscale lithium sodium titanate particles. Sonochemical synthesis reduces the lithium sodium titanate particle size down to 80–100 nm vis-à-vis solid-state method delivering larger (200–500 nm) particles. Independent of the synthetic methods, the end products deliver reversible electrochemical performance with reversible capacity exceeding 80 mAh·g−1 acting as a 1.3 V anode for Li-ion batteries.
Tin (Sn)-based materials are potential alternatives to the commercial graphite anode for next-generation Li-ion batteries (LIBs) due to their high theoretical capacity. However, the poor cyclic stability, originating from the large volumetric changes during charge/discharge process, hinder their practical utilization. Herein, we have successfully prepared a Sn-based metal-organic framework (MOF, Sn-PMA), and explored as potential anode materials in LIBs. Benefiting from its layered structure and efficient electron transport channels, Sn-PMA electrodes deliver a high initial capacity of 1567 mAh g−1, at 100 mA g−1, and maintained a reversible capacity of 707 mAh g−1, at 800 mA g−1, after 400 cycles. Furthermore, the detailed post-electrochemical structural, morphological and compositional analysis is carried out to unveil the structural changes and Li-ion storage mechanism of electrodes. Ex-situ XRD and XPS results revealed that, in Sn-PMA electrode, O atom, coordinated to the Sn atom, exhibited higher electronegativity, served as major Li-ion storage site and rendered excellent cyclic stability due to a stable structure. Kinetic analyses reveal that the excellent performance of the Sn-PMA is typical attributed to the pseudocapacitive contribution induced by the special porous structure.
The transition to renewable energy sources has created need for stationary, low-cost electrical energy storage. A possible technology to address both cost and environmental concerns are batteries based on organic materials. The use of oligoanthraquinones as a replacement for metal hydrides or cadmium in nickel hydroxide rechargeable batteries is investigated in detail regarding polymer composition, electrochemical reversibility and electroactive species cost. Two different oligoanthraquinones are paired with a nickel hydroxide cathode and demonstrate cycling stability dependent on parameters such as supporting electrolyte strength, C-rate, and anode swelling. The energy efficiencies are up to 75 % and the cell potential up to 1.13 V. Simple functionalization of the basic structure increases the cell potential by 100 mV.
Seventy-six plant extracts including methanolic and successive water extracts from 37 Indian medicinal plants were investigated for acetylcholinesterase (AChE) inhibitory activity (in vitro). Results indicated that methanolic extracts to be more active than water extracts. The potent AChE inhibiting methanolic plant extracts included Withania somnifera (root), Semecarpus anacardium (stem bark), Embelia ribes (Root), Tinospora cordifolia (stem), Ficus religiosa (stem bark) and Nardostachys jatamansi (rhizome). The IC50 values obtained for these extracts were 33.38, 16.74, 23.04, 38.36, 73.69 and 47.21μg/ml, respectively. These results partly substantiate the traditional use of these herbs for improvement of cognition.