batterydata/paper-abstracts huggingface dataset:
A semi-liquid polysulfide cathode renders a higher sulfur loading for Li-S batteries. However, the aggravated polysulfide shuttle effect and the poor interaction between polysulfide and carbonaceous electrode lower the battery’s cycling stability and performance. Here we report a freestanding N-TiO2 nanowire (NW) decorated carbon cloth electrode for a Li-polysulfide battery, where the nitrogen doping in the formed nanowires allows for a higher electrical conductivity and stronger polysulfide binding ability. Meanwhile, with the facile adsorption of S 4 2 − and more active sites provided by the nanowire structure, Li2S precipitation can be improved as well. With the rationally engineered nanostructured polysulfide binding electrode, the battery achieves a remarkably enhanced cycling stability and prolonged discharge capacity (1210mAhg−1, 0.2C and 600mAhg−1, 1C), in comparison with the pristine carbon cloth (890mAhg−1, 0.2C and 210mAhg−1, 1C). The facile strategy of fabricating conductive and polysulfide binding nanostructure in this work is thus expected to facilitate the design of high-energy sulfur cathode.
Analogous to the well-known Li–S battery, an electrochemical reaction of two Li + ion with one Se atom (2Li+ + Se + 2e− = Li2Se) gives rise to a large specific theoretical capacity of 678 Ah kg−1 at around ∼2.4 V, resulting in 1627 Wh kg−1 of specific energy. Given this much larger energy density than present cathode materials show, selenium nanofiber and its composites with the conducting polymer polypyrrole as well as with graphene have been prepared and electrochemically tested as cathode materials for Li-batteries. At a low current rate of C/120, pure t-Se electrode delivers the theoretical specific capacity, which subsequently drops to 100 Ah kg−1 at C/20. As expected, composite formation with polypyrrole and graphene improves the electrochemical performance compared to trigonal selenium (t-Se) fibers. While polypyrrole coating minimizes the polarization between charging and discharging, graphene wrapping enhances the obtainable capacity at moderate cycling rates. Ex-situ X-ray diffraction of the electrode reveals solid solution behavior in the initial stages of lithiation, finally leading to an electrochemical conversion of selenium to Li2Se.
The low-heating solid-state method has been adopted to synthesize LiNi1/3Co1/3Mn1/3O2 materials. The final product, with homogeneous phase and smooth crystals indicated by XRD and SEM results, can be synthesized at 700°C, much lower than the synthesis temperatures of co-precipitation method. The reaction process and microstructure of precursor has been investigated by IR spectrum. By comparative studies with the mixture of CH3COOLi and (Ni, Co, Mn)(C2O4), it is testified that the precursor is homogeneous, rather than a mixture. The decomposition process and the reaction energy have been studied to investigate the reaction mechanism of the precursor when heated at high temperature. The as-synthesized LiNi1/3Co1/3Mn1/3O2 exhibits excellent electrochemical properties, exhibiting initial specific capacity of 167mAhg−1 with stable cyclic performance.
Benefiting from lower operational costs and energy requirements than do hydrometallurgical and pyrometallurgical processes in metal recovery, the bioleaching of LiCoO2 through the use of sulfur-oxidizing and iron-oxidizing bacteria has drawn increasing attention. However, the bioleaching mechanism of LiCoO2 has not been clearly elaborated. In the present study, the effects of the energy source of bacteria, such as Fe2+, pyrite and S0, and the products of bacterial oxidation, such as Fe3+ and sulfuric acid, on the chemical leaching of LiCoO2 were studied. The results indicated that lithium was dissolved by acid, and cobalt was released by the reduction of Fe2+ and acid dissolution. The recovery of Li+ and Co2+ could be significantly improved by pH adjustment. Finally, optimal recoveries of Li+ and Co2+ were observed in the pyrite group, reaching 91.4% and 94.2%, respectively. By using pyrite as the energy source, the role of bacteria in bioleaching of LiCoO2 was investigated. The results showed that bacteria could produce sulfuric acid by oxidizing pyrite to promote the mobilization of Li+ and Co2+. The recovery of lithium and cobalt could be increased to 100.0% and 99.3% by bacteria. Moreover, extracellular polymeric substances secreted by bacteria were found to be a factor for the improvement of Li+ and Co2+ recovery.
Continuous monitoring of aberrant electrical rhythms during heart injury and repair requires prolonged data acquisition. We hereby developed a wearable microelectrode membrane that could be adherent to the chest of neonatal mice for in situ wireless recording of electrocardiogram (ECG) signals. The novel dry-contact membrane with a meshed parylene-C pad adjacent to the microelectrodes and the expandable meandrous strips allowed for varying size of the neonates. The performance was evaluated at the system level; specifically, the ECG signals (μV) acquired from the microelectrodes underwent two-stage amplification, band-pass filtering, and optical data transmission by an infrared Light Emitting Diode (LED) to the data-receiving unit. The circuitry was prototyped on a printed circuit board (PCB), consuming less than 300 μW, and was completely powered by an inductive coupling link. Distinct P waves, QRS complexes, and T waves of ECG signals were demonstrated from the non-pharmacologically sedated neonates at ~600 beats per minutes. Thus, we demonstrate the feasibility of both real-time and wireless monitoring cardiac rhythms in a neonatal mouse (17–20 mm and <1 g) via dry-contact microelectrode membrane; thus, providing a basis for diagnosing aberrant electrical conduction in animal models of cardiac injury and repair.
A 17-day pilot study investigating potential PM exposures of an elderly population was conducted near Baltimore, Maryland. Collection of residential indoor, residential outdoor, and ambient monitoring data associated with the subjects living at a common retirement facility was integrated with results from a paired epidemiological pilot study. This integration was used to investigate the potential pathophysiological health effects resulting from daily changes in estimated PM exposures with results reported elsewhere. Objectives of the exposure study were to determine the feasibility of performing PM exposure assessment upon an elderly population and establishing relationships between the various exposure measures including personal monitoring. PM2.5 was determined to be the dominant outdoor size fraction (0.83PM2.5/PM10 mass ratio by dichot monitoring). Individual 24-h PM1.5 personal exposures ranged from 12 to 58μgm−3. Comparison of data from matched sampling dates resulted in mean daily PM1.5 personal, PM2.5 outdoor, and PM1.5 indoor concentrations of 34, 17, and 17μgm−3, respectively. Activity patterns of the study population indicated a generally sedentary population spending a mean of 96% of each day indoors. Future studies would benefit from the use of a consistent sampling methodology across a larger number of PM measurement sites relevant to the elderly subjects, as well as a larger personal PM exposure study population to more successfully collect data needed in matched epidemiological-exposure studies.
To determine whether systemic medical factors, such as vascular risk factors, metabolic and inflammatory markers contribute to cognitive decline in Parkinson’s disease (PD); if confirmed to determine whether a clinically applicable risk factor model can predict the conversion from normal cognition (NC) to mild cognitive impairment (MCI). 58 patients who met the UK Brain Bank Criteria for PD underwent clinical and laboratory assessment at study entry; 47 patients were re-assessed after 2 years. Medical history, vascular risk (QRISK2), blood metabolic and inflammatory factors, brain vessel examinations, activity of daily living, and neuropsychological testing were performed. Forty patients had NC and 18 patients had MCI at baseline. Patients with MCI had higher level of interleukin 6, folic acid below normal range and higher
Three-dimensional (3-D) composite electrodes are prepared by one-step sintering of the laminated LiCoO2 and 0.44LiBO2·0.56LiF pellets, in which the amorphous 0.44LiBO2·0.56LiF solid electrolyte melts during the sintering process and fills the interspaces in the underlying highly conductive 3-D frame formed by LiCoO2. The one-step sintering process yields a compact electrode structure of ∼92% in relative density, which contains no electronic conductive additives or polymer binder. For better characterization of the composite electrode, liquid electrolyte is used in the battery test, but the vast majority of the active material is in the all-solid-state environment. The specific capacity of the 3-D composite electrode is dependent on the thickness of the composite electrodes. The 100-μm-thick 3-D composite electrode possesses high specific discharge capacity of 131 mAh g−1 at C/20 rate (96% utilization of the active material), excellent cycling performance for the measured 20 cycles and good rate capability at various discharge rates. The 200-μm-thick 3-D composite electrode delivers 88% of the theoretical capacity, i.e., 120 mAh g−1, and a significantly enhanced surface capacity of ∼9 mAh cm−2, which is much higher than that of the electrode used in the conventional all-solid-state lithium battery.
Spinel LiMn2O4 has been prepared by a facile hydrothermal procedure and the prepared LiMn2O4 exhibits superior electrochemical performance, such as high specific capacitance (409Fg−1 at 2mVs−1) and excellent rate capability (85% retention at 100mVs−1). In order to achieve high energy and power densities, a high-voltage asymmetric supercapacitor (ASC) is successfully assembled using the as-prepared LiMn2O4 as the positive electrode and nitrogen-doped graphene/porous carbon composite as the negative electrode in a Li2SO4 aqueous electrolyte. The optimized ASC delivers a high specific energy of up to 44.3Whkg−1 at a specific power of 595Wkg−1 with an output voltage of 1.8V based on the total weight of the active electrode materials. This novel strategy provides a promising route to design high-performance supercapacitors with high energy density for next-generation storage systems.
A series of graphene-enveloped sulfur (G/S) composites with different sulfur particle sizes and high sulfur contents of 82wt% are synthesized using a double solvent approach for lithium–sulfur batteries. This double solvent approach is facile, low cost, and effective in preparing graphene–sulfur composites for large-scale production. Scanning electron microscopy and energy dispersive X-ray spectroscopy mapping were used to verify the structure and composition of the G/S composites. The graphene-coating layers not only provide a conductive carbon matrix surrounding the sulfur particles but also prevent the soluble polysulfide intermediates dissolving into the electrolyte. The sizes of sulfur particles can be controlled by adjusting the ratios of double solvent (CS2/alcohol) and may further affect the electrochemical behavior. When used as cathode materials for lithium–sulfur batteries, the G/S-200 composite with the smallest sulfur particle size shows an initial discharge capacity of 1068.5mAhg−1 and retains 729.5mAhg−1 after 100 cycles at 0.1C. This novel double solvent method is a promising approach to obtain other carbon sulfur composites.
Predicting measurable thermodynamic and kinetic properties of solids from first-principles requires the use of statistical mechanics. A major challenge for materials of technological importance arises from the fact that first-principles electronic structure calculations of elementary excited states are computationally very demanding. Hence statistical mechanical averaging over the spectrum of excited states must rely on the use of effective Hamiltonians that are parameterized by a limited number of first-principles electronic structure calculations, but nevertheless predict energies of excited states with a high level accuracy. Here we review important effective Hamiltonians that account for vibrational and configurational degrees of freedom in multi-component crystalline solids and show how they can be used to predict phase stability as a function of composition and temperature as well as kinetic transport constants such as diffusion coefficients in non-dilute crystalline solids.
Enhancing anode performance is a critical step to improving the power output and energy storage of microbial fuel cells (MFCs). In this study, MFCs containing pseudocapacitive anode materials, such as polypyrrole-carboxymethyl cellulose (PPy-CMC) composite films, were used to coat the nitrogen-doped carbon nanotube (N-CNT)/sponge (S) for use in MFCs. The capacitive anode could function as a bioanode, store electrons generated from the microbial oxidation of a substrate, and release the accumulated charge as needed. Scanning electron microscopy results indicated that the composite anode had a three-dimensional macroporous structure with a large specific surface area, providing more sites for microbial attachment and growth. Experimental results showed that MFCs equipped with PPy-CMC/N-CNT/S capacitive bioanodes had a maximum power density of 4.88 W m−3, which was 1.34 and 1.71 times as much as those of PPy/N-CNT/S and N-CNT/S bioanodes (3.65 and 2.85 W m−3), respectively. Moreover, the charge–discharge time of 60–90 min, the total charge Qm of the MFC equipped with the PPy-CMC/N-CNT/S anode was the largest (5154.08 mC cm−2)—5.7 times higher than that of the N-CNT/S anode. The excellent performance of the MFC equipped with the PPy-CMC/N-CNT/S anode was attributable to the composite materials, which exhibited a large-pore structure, good biocompatibility, large capacitance, and high specific surface area. Therefore, this synthesized composite exhibited potential as a capacitive and biocompatible anode material in MFCs.
An electrochemical cell using an electrode of expanded metal (EXMET®) is demonstrated. The sheet of EXMET® contains voids with open volume and geometric arrangement that are capable of locally absorbing any lateral expansion. Consequently, all cumulative changes in the plane of the EXMET®, when an Li–Al alloy is initially formed, are avoided. Three configurations of electrochemical generators utilizing cathodes of V2O5, FePO4 and LiCoO2 are described. Studies of alloy and dense anode sheets with local stress relaxation were demonstrated by in situ optical microscopy (OM) and scanning electron microscopy (SEM) using expanded metal. These studies indicate that a dense anode offers advantages for application in SPE-cells, including safety, long life and reliability.
Structural change of Cr-doped LiFePO4/C during cycling is investigated using conventional and synchrotron-based in situ X-ray diffraction techniques. The carbon-coated and Cr-doped LiFePO4 particles are synthesized by a mechanochemical process followed by a one-step heat treatment. The LiFe0.97Cr0.03PO4/C has shown excellent rate performance, delivering the discharge capacity up to 120mAh/g at 10C rate. The results suggest that the improvement of the rate performance is attributed to the chromium doping, which facilitates the phase transformation between triphylite and heterosite during cycling, and conductivity improvement by carbon coating. Structural analysis using the synchrotron source also indicates that the doped Cr replaces Fe and/or Li sites in LiFePO4.
The influence of the rare earth metal, samarium, as an alloying additive on the electrochemical behaviour of pure lead is studied by means of X-ray diffraction, self-depassivation, linear sweep voltammetry and a.c. impedance spectroscopy in 4.87M H2SO4 at 25°C. Studies on Pb–Sm alloys (Sm=0.02, 0.04, and 0.12wt.%) indicate that the oxide film formed on the alloy surface at 0.9V is thicker than that on pure lead when the alloy contained less than 0.1wt.% Sm. In addition, samarium exercises little influence on the conversion of PbSO4 to PbO2 in the oxide film during charging. The electrochemical impedance of the oxide film is much larger than that of the oxide formed on pure lead. With the addition of more than 0.1% Sm, however, the oxide film on the alloy surface is thinner and samarium obviously promotes the conversion of passive PbSO4 in oxide film to conductive PbO2. The a.c. impedance data show that a high content of samarium greatly inhibits the growth of the passivation layer and decreases the electrochemical impedance of the film.
Morphology-controlled graphene nanosheets can be easily synthesized as anode material for application in high-capacity lithium-ion batteries. A modified version of an improved method for higher degree of oxidation of graphite oxide (GO) has been developed and characterized. X-ray diffraction analysis shows that GO prepared using this method has a higher degree of oxidation than that of using the improved method. The interlayer d-spacing increases from 0.87nm (using the improved method) to 0.92nm (using the modified-improved method). Also, it is confirmed by XPS analysis that the O/C ratio in GO increases from 2.51 (improved method) to 8.27 (modified-improved method). It is hypothesized that GO, which has a higher degree of oxidation, is more reducible to graphene. The more reduced graphene has a larger amount of free π-bonds and fewer layers, and it can be easily altered to morphology-controlled graphene. Graphene nanosheets prepared using the modified-improved method exhibits discharge capacities of 1079 mAh g−1 (at a constant current of 40mAg−1) and 1002 mAh g−1 after 50 cycles. The capacity retention of the synthesized graphene nanosheets is 1070 mAh g−1 at a current of 40mAg−1 after the rate capability test, and their rate capability is 463 mAh g−1 at a current of 400mAg−1. The morphology-controlled graphene nanosheets prepared by the modified-improved method shows better discharge performance compared to graphene prepared by the improved method.
Composites based on polyoxometalates (POMs) and nanostructured carbon such as carbon nanotubes (CNTs) or graphene have attracted widespread attention as they combine the unique chemical reactivity of POMs with the unparalleled electronic properties of nanocarbons. The exceptional properties of these composites have been employed in catalysis, energy conversion and storage, molecular sensors and electronics. Herein, we summarize the latest progress in POM/CNT and POM/graphene nanocomposites with a focus on energy materials for water splitting and fuel cells, composite electrode materials for batteries and supercapacitors as well as composites for environmental pollutant sensing. Current applications are critically assessed and promising future target systems are discussed.
A facile and reliable method has been developed to synthesize nanohybrids of anatase TiO2 nanoparticles-decorating carbon nanotubes (CNTs@TiO2). The nanohybrid displays a unique feature of having CNTs encapsulated inside and anatase TiO2 nanoparticles coating on the CNT surface. Comprehensive characterizations suggest that CNTs@TiO2 nanohybrids exhibit unique properties of CNTs and TiO2 nanoparticles with one-dimensional structure, excellent electrical conductivity, high surface area, and good biocompatibility. The electrochemical properties of CNTs@TiO2 nanohybrids were systematically investigated, it was revealed that the CNTs@TiO2 nanohybrids showed great promise as anode materials of microbial fuel cells (MFCs). Compared with pure TiO2 nanoparticles and CNTs alone, CNTs@TiO2 nanohybrids exhibited a much higher output current, power density, and Coulombic efficiency when used as anode materials of MFCs. The as-developed synthetic route opens up a new avenue for designing CNTs-based nanohybrid materials for various applications benefiting from the synergetic effect among constituents.
The inherent technical challenges of lithium–sulfur (Li–S) batteries have arisen from the intrinsic redox electrochemistry occurring on the Li and S electrodes, which can significantly deteriorate the S utilization and life cycle. Two-dimensional (2D) nanomaterials composed of atomic or near-atomic thickness with infinite lateral dimensions have been proven to be meritorious as emerging materials for energy storage applications due to their unique structures, remarkable physical properties, and tunable surface chemistry. Herein, we argue that surface functionalization or heteroatom doping of 2D materials, hybridization with other nanostructured materials (0D quantum dots, 1D nanotubes/nanowires, and other 2D nanosheets), and finally architecting into 3D structures along with the advantages of 2D building blocks can open up new opportunities for Li–S batteries. We also focus on the future directions of Li–S batteries in the design of S cathodes and separators utilizing the intrinsic and extrinsic properties of 2D nanomaterials.
The activity of zinc administered intraperitoneally, acutely (in single dose), sub-chronically (in triple doses) or chronically (once daily for 14 days) were assessed in the forced swim test (FST) and olfactory bulbectomy (OB) model of depression in rats. Previously, we have demonstrated that acute administration of zinc sulfate is active in FST in rats and mice. In the present study, zinc hydroaspartate in a dose of 65mg/kg (11.5mgZn/kg), all: acute, sub-chronic and chronic administration, reduced the immobility time in the FST in rats. Removal of olfactory bulbs (OB surgery) in rats is associated with variety of behavioral abnormalities such as deficit in a step-down passive avoidance or hyperactivity in the “open field” test. Both acute and chronic administration of zinc hydroaspartate reduced the number of trials needed to the learning passive avoidance and reduced the OB-induced hyperactivity in rats. At the time schedule following zinc hydroaspartate administration, when behavioral experiments were performed, the serum zinc concentrations were significantly higher than control-physiological values. These results confirm activity of zinc in the FST, show its antidepressant-like activity in the OB rat model of depression, demonstrate the lack of tolerance to these effects and suggest relationship of these antidepressant-like effects with the rise in serum zinc. These animal data further suggest antidepressant activity of zinc in human depression.
Residues reclaimed from a municipal solid waste (MSW) landfill were characterized for the concentrations of a number of heavy metals. The residue fractions analyzed included a fine fraction (<0.425 mm), an intermediate fraction (>0.425 and <6.3 mm) and a fraction consisting of paper products that could ultimately degrade to a smaller size. The intermediate fraction appeared to be organic in nature, while the fine fraction was more soil-like. In general, the metal concentrations were greatest in the intermediate fraction and lowest in the fine fraction. The effect of sample age on the elemental content was also investigated. The concentrations of several elements were greater in older samples (sample ≈8 years in age) when compared to newer samples (sample ≈3 years in age). Limitations associated with the land application of residual soil (composed of the fine and intermediate fractions) were assessed by comparing measured concentrations to regulatory threshold values. In general, most metal concentrations were below regulatory thresholds for use in unrestricted settings. At the concentrations measured, however, several elements might limit reuse options, depending on which regulatory threshold serves as a benchmark. Elevated concentrations of arsenic presented the greatest limitation with respect to common US thresholds while elevated cadmium concentrations presented the greatest limitation when compared to UK thresholds. The source of the arsenic was determined to be the waste, not the cover soil.