batterydata/paper-abstracts huggingface dataset:
A serials of micro-sized Li3−x Na x V2(PO4)3/C composite has been synthesized by sol-gel method, comprised of numerous primary nanocrystals. This structure can efficiently facilitate lithium-ion transport in secondary aggregated individual particles due to the short diffusion distance among primary nanocrystals, along with a high tap density. With the increasing of Na doping content, the structure evolution occurs in Li3-x Na x V2(PO4)3 from a single-phase structure to a two-phase structure. The appearance of rhombohedral phase can provide a larger free volume of the interstitial space, fastening ionic movement to offer an excellent high rate capability. Furthermore, Na doping can stabilize the rhombohedral structure of the V2(PO4)3 framework, leading to the remarkable cycling stability. Among all the composites, Li2.6Na0.4V2(PO4)3/C presents the best electrochemical performance with a high energy density of 478.8 Wh kg−1, delivering high initial discharge capacities of 121.6, 113.8 and 109.7 mAh g−1 at the rate of 5 C, 10 C and 20 C in a voltage range of 3.0 – 4.3 V, respectively. It also exhibit an excellent high rate cycling performance, with capacity retention of 85.9 %, 81.7 % and 76.5 % after 1000 cycles at the rate of 5 C, 10 C and 20 C in a voltage range of 3.0 – 4.3 V.
Abstract Improving the sensing sensitivity and lowering the working temperature are the critical issues for the practical application of gas sensors. For a gas sensor, the sensing materials play important roles in determining the sensing properties. In the present work, γ-Fe2O3 microspheres composed of nanoparticles were successfully fabricated by a typical facile hydrothermal process and a following annealing treatment. Interestingly, the as-synthesized γ-Fe2O3 microspheres showed excellent sensing properties for the detection of ethanol gas with high sensitivity, and especially working temperature as low as room temperature. The gas sensing results showed that at the optimal operating temperature (200 °C), the response intensity of γ-Fe2O3 microspheres for 1000 ppm ethanol gas could reach 74.6 and the limit of detection (LOD) was about 0.026 ppm. At room temperature, the γ-Fe2O3 microspheres still demonstrated a good response to different concentrations of ethanol gas from 1 to 1000 ppm, with a very good selectivity over other gas species and a good stability. This study indicated that the γ-Fe2O3 phase could be a type of promising room-temperature gas sensing material for ethanol gas detection.
The role of different mass loadings on the corresponding areal capacities, capacity retention, and rate performance in high-capacity Ge electrodes was studied. Micro-sized porous Ge powders were synthesized by a facile single-step reduction of GeO2 with hydrogen gas. The porous Ge electrode exhibited a high capacity retention over 1800 cycles at 8 A/g (∼73% retention) at the low loading of 0.56 mg/cm2. Even with the high loading of 4.45 mg/cm2, high areal capacity (>3 mAh/cm2) for over 100 cycles were observed. Excellent electrochemical stability for a full cell was also observed for about 180 cycles with a LiCoO2 cathode. Post cycling analysis reveals that the stability of the porous electrode stems from the ability of the grains to maintain their electrical contacts with each other even after undergoing transformation in the morphology and crystallinity.
X-ray photoelectron spectroscopy (XPS) has been used to study the depth profile of the solid–electrolyte interphase (SEI) formed on a graphite powder electrode in a Li-ion battery. The morphology of the SEI-layer, formed in a 1M LiBF4 EC/DMC 2:1 solution, consists of a 900Å porous layer of polymers (polyethylene oxide) and a 15–20Å thin layer of Li2CO3 and LiBF4 reduction–decomposition products. Embedded LiF crystals as large as 0.2μm were found in the polymer matrix. LiOH and Li2O are not major components on the surface but rather found as a consequence of sputter-related reactions. Monochromatised Al Kα XPS-analysis based on the calibration of Ar+ ion sputtering of model compounds combined with a depth profile analysis based on energy tuning of synchrotron XPS can describe the highly complex composition and morphology of the SEI-layer.
Trace elements contamination in the aquatic ecosystem is a current and major environmental concern due to their non-degradable nature and toxic effects on human health. Concentrations of arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb) in fish were estimated to evaluate contamination levels and health risks for Bangladeshi adults. A total of six demersal fish species namely Mystus vittatus, Polynemus paradiseus, Sillaginopsis panijus, Lates calcarifer, Cynoglossus arel and Pseudapocryptes elongates were collected in summer and winter season from the coastal Karnaphuli River, Bangladesh. The analyzed trace elements varied between different species of fish. The concentration of studied trace elements exceed Food and Agriculture Organization/World Health Organization maximum tolerable intake indicating risk to human body. The mean concentration of As, Cr, Cd and Pb were found 2.18, 9.1, 7.2 and 4.38 times higher than the recommended value. Health risks associated with these trace element intakes were evaluated in terms of dietary intake and target hazard quotients (THQs). The THQs value for individual fish species was more than one which was responsible for non-carcinogenic health hazard due to fish consumption. Target Carcinogenic Risk (TR) value for arsenic and lead was also higher than USEPA standard (10−4) indicated chronic cancer risk to human. From the health point of view, this study showed that the inhabitants who consume these fishes are exposed chronically to trace elements pollution with carcinogenic and non-carcinogenic consequences.
Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed.
Accumulated evidence suggests that neuropeptide Y (NPY) is involved in emotional disorders by acting on Y1 and Y2 receptors. This hypothesis is based on animal studies carried out in naïve normal animals but not in animal models of depression, including the olfactory bulbectomized (OBX) rat. The OBX rat produces a wide array of symptoms that mimic several aspects of human depression and anxiety disorders. In the present study, we aimed to investigate the effects of sustained (2 weeks) intracerebroventricular administration of NPY Y1 and Y2 agonists and antagonists in a battery of behavioral tests including the open field, forced swim test (FST) and social interaction (SI) tests in OBX rats. The levels of Y1 and Y2 receptors in the hippocampus and basolateral amygdala (BLA) were also evaluated. Treatment with the Y1-like receptor agonist, [Leu31Pro34]PYY, decreased both depressive- and anxiogenic-like behaviors. The Y2 receptor antagonist, BIIE0246, decreased the immobility time in the FST in OBX animals and increased active contacts in the SI test in sham rats. The Y2 agonist, PYY3-36, increased the immobility time in the FST in OBX rats. Additionally, increased levels of Y2 receptor binding were quantified in the dorsal hippocampus and BLA in OBX rats. Taken together, the autoradiographic results add further evidence that the NPYergic system is altered in disturbed emotional states. Moreover, we demonstrate a differential role for NPY Y1 and Y2 receptors in emotional processes under control and challenged conditions. This article is part of a Special Issue entitled ‘Anxiety and Depression’.
The polysulfide ions formed during the first reduction wave of sulfur in Li–S battery were determined through both in-situ and ex-situ derivatization of polysulfides. By comparing the cyclic voltammetric results with and without the derivatization reagent (methyl triflate) as well as the in-situ and ex-situ derivatization results under potentiostatic condition, in-situ derivatization was found to be more appropriate than its ex-situ counterpart, since subsequent fast chemical reactions between the polysulfides and sulfur may occur during the timeframe of ex-situ procedures. It was found that the major polysulfide ions formed at the first reduction wave of elemental sulfur were the S 4 2 − and S 5 2 − species, while the widely accepted reduction products of S 8 2 − and S 6 2 − for the first reduction wave were in low abundance.
Supercapacitors have attracted intense attention due to their great potential to meet the demand of both high energy density and power density in many advanced technologies. Various carbon-based nanocomposites are currently pursued as supercapacitor electrodes because of the synergistic effect between carbon (high power density) and pseudo-capacitive nanomaterials (high energy density). This feature article aims to review most recent progress on 3D (3D) carbon based nanostructures for advanced supercapacitor applications in view of their structural intertwinement which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The carbon nanostructures comprise of CNTs-based networks, graphene-based architectures, hierarchical porous carbon-based nanostructures and other even more complex carbon-based 3D configurations. Their advantages and disadvantages are compared and summarized based on the results published in the literature. In addition, we also discuss and view the ongoing trends in materials development for advanced supercapacitors.
It is the wish of both people with cognitive impairment and their informal caregivers for the impaired person to live at home for as long as possible. This is also in line with economic arguments about health. The existing structure of day-care services for the elderly can be used to achieve this. Due to the current lack of empirical evidence in this field, most day-care centres do not offer a scientifically evaluated, structured intervention, but instead offer a mixture of individual activities whose efficacy has not yet been established. Informal caregivers of people with dementia use day-care centres primarily to relieve themselves of their care tasks and as a support service.
Global climate change caused by the accumulation of greenhouse gases (GHGs) has caused concerns regarding the continued reliance on fossil fuels as our primary energy source. Hydrocarbons produced from biomass using microbial fermentation processes can serve as high-quality liquid transportation fuels and may contribute to a reduction in GHG emissions. Here, we discuss the barriers and opportunities for bio-based production of hydrocarbons to be used as diesel and jet fuels and review recent advances in engineering microbes for production of these chemicals. There are two main challenges associated with establishing bio-based hydrocarbon production from cheap feedstocks; lowering the cost of developing efficient and robust microbial cell factories and establishing more efficient routes for biomass hydrolysis to sugars for fermentation. We discuss how to develop novel systems and synthetic biology tools that can enable faster and cheaper construction of microbial cell factories and thereby address the first challenge, as well as recent advances in biomass processing that will likely lead to overcoming the second challenge in the near future.
The concept of a self-powered water desalination device with the capability of simultaneous electricity generation is introduced. The as-fabricated metal-air desalination battery takes the advantage of integration of ion selective membranes with an aluminum-air battery in a three-chamber cell. The maximum power density of 2.83 W m−2 at 6.58 A.m−2 current density and 0.43 V output voltage is obtained using natural saltwater as the electrolyte. The as-fabricated device decreases the salinity of Caspian saltwater by 37.8% with 10 mW h energy generation in 14-h operation. The obtained results are promising to present considerable room for improvement of the as-fabricated device.
The design and development of durable and high efficient supercapacitors is highly desired in electronic and energy storage devices. Traditional carbon based capacitors suffer from low specific capacitance and energy density. Recently transition metal sulfides are attractive alternatives for crystal electrode materials. Herein we demonstrate a facial design and synthetic method to grow novel metal sulfide double-shelled polyhedral nanocages consisting of mesoporous amorphous Ni x S y @CoS via a metal-organic-framework engaged strategy for use in supercapacitors. The Ni x S y @CoS polyhedrons with the inner and outer-shells respectively consisting of CoS and Ni x S y are obtained at mild room temperature without further thermal-treatment. The outer-shell is easily adjustable to suit various combinations according to the requirement. The morphological and structural evolution of the Ni x S y @CoS nanocages was studied systematically. Further electrochemical performance shows that the Ni x S y @CoS exhibits remarkably high capacitance of 2291Fg−1 at 1.0Ag−1 in 6M KOH aqueous solution.
A series of M-doped polypyrrole (PPy)-modified BP2000 catalysts (M=Mn, Fe, Co, Ni, and Cu) are synthesized using the hydrothermal method. The synergy among a transition element, nitrogen, and carbon for oxygen reduction reaction (ORR) in alkaline medium is discussed based on the physical characterization and electrochemical analyses of the Co-doped PPy-modified BP2000. PPy is found to adhere carbon black particles together to form a porous 3D network during the PPy modification on BP2000. PPy reconfiguration occurs during the hydrothermal treatment process. The individual interactions between BP and PPy, BP and Co, and Co and PPy exhibit insignificant effects on the enhancement of ORR. The cooperative interaction among Co, N, and C plays a very important role in the enhancement of ORR. The doping effect of transition-metal salt on ORR enhancement depends on the nature of the transition element and the corresponding anion.
The development of sodium ion batteries as alternative technology to the lithium ion depends on the design of electrode based on cheap and high abundant elements. Iron oxides are potentially good candidates as negative electrode thanks to their high specific capacity, but they suffer from poor electronic transport properties and large volume change during sodiation/de-sodiation cycles. Stable performance in hematite or magnetite based electrodes requires the use of Fe/C composites made by expensive carbon precursors such as graphene oxides or carbon nanotubes. However, the limits of iron (III) oxide can also be tackled using a different approach by combining the advantages of the nanostructuring and the doping with an aliovalent element. In this work, we present for the first time the use of Si-doped Fe2O3 nanofibres obtained by an easy scalable process based on the electrospinning method. The silicon doping does not just improve the transport properties but induces also changes in the structure and morphology. The electrochemical results show that the Si-doped Fe2O3 fibres deliver an anodic capacity of 350 mAh·g−1 at the average potential of 1.5 V vs. Na+/Na after 70 cycles, a result never achieved for iron oxide based electrode standard formulation.
In our work, a series of Li1-xMxCoO2 (M = Na, x = 0–0.05) samples are synthesized by the solid-state calcination route. Electrochemical measurements show that high-rate capacities and high-voltage performances receive obvious improvements with an appropriate content of Na-doping. Specially, the capacity retentions of Li0.97Na0.03CoO2 and LiCoO2 are 65.6% and 62.7% after the 100th cycle at 3.0–4.5 V, respectively. The discharge capacity of Li0.97Na0.03CoO2 compared with the pristine electrode LiCoO2 is greatly enhanced from 125 to 135 mAh·g−1 at the rate of 5 C and 98 to 120 mAh·g−1 at the rate of 10 C (1C = 140 mA g−1) respectively. With the larger radius of Na+ substituted for the smaller radius of Li+, it is found that the bond length of LiO is reduced from 2.0801 Å to 2.0781 Å, which is helpful for stabilizing the structure of LiCoO2 and improving the cycle capability at high voltages. At the same time, the inter-planar distance of Li slabs is expanded from 2.5904 Å to 2.59511 Å which can accelerate the diffusion of Li+ and improve the rate capacity. Therefore, Na-doped LiCoO2 shows outstanding high-voltage and high-rate performances, and the strategy can also be popularized and applied to other layered cathodes.
As the waste industry continues to move from a disposal-based system to one based on a combination of recovery options, the need for information on the composition of waste increases and this is reflected by the amount of information on the physical composition of municipal solid wastes that is now available. However, there is far less information on the chemical composition of municipal solid waste. The results from a number of chemical surveys from Europe are compared and show a reasonable degree of agreement, but several problems were identified with the data. Chemical and physical compositional data are combined in a case study example to investigate the flow of key potential pollutants in an integrated solid waste management system that uses materials recycling, composting, incineration and landfilling. This case study has shown that an integrated waste management strategy diverts lead and cadmium away from composting and recycling to incineration, which effectively isolates these elements from the environment through efficient capture of the pollutants followed by secure landfilling or recycling of the residues. However, further work is needed to determine the distribution of mercury in incineration residues and its fate when the residues are landfilled.
Ordered mesoporous NiCo2O4 (OM NiCo2O4) materials have been synthesized via KIT-6 template and used as bifunctional electrocatalyst for rechargeable Li-O2 batteries. Characterization of the catalyst by X-ray diffractometry and transmission electron microscopy confirms the formation of a single-phase, 3-dimensional, ordered mesoporous NiCo2O4 structure. The as-prepared OM NiCo2O4 exhibits a specific surface area of 95.5 m2 g−1 with mesoporous peaks between 3 and 5nm. Linear scanning voltammetric measurements reveal that OM NiCo2O4 exhibits slightly higher catalytic activity for the oxygen reduction reaction but much higher activity for the oxygen evolution reaction than Ketjen black (KB) carbon. The Li-O2 battery utilizing OM NiCo2O4 shows a slightly higher discharge voltage plateau and a higher specific capacity of 4120 mAh g−1 than that with pure KB, and the subsequent charge voltage is much lower than that with KB. Moreover, an enhanced cyclability of Li-O2 battery with OM NiCo2O4 cathode is observed with a capacity retention ratio of 65.4% after 5 cycles. When restricting the discharge capacity at 1000 mAh g−1, Li-O2 battery with OM NiCo2O4 cathode shows an improved cyclability and the cut-off voltage is as high as 2.4V after 20 cycles, suggesting that OM NiCo2O4 could be as a promising catalyst for Li-O2 batteries.
The electrochemistry-based battery model can provide physics-meaningful knowledge about the lithium-ion battery system with extensive computation burdens. To motivate the development of reduced order battery model, three major contributions have been made throughout this paper: (1) the transfer function type of simplified electrochemical model is proposed to address the current-voltage relationship with Padé approximation method and modified boundary conditions for electrolyte diffusion equations. The model performance has been verified under pulse charge/discharge and dynamic stress test (DST) profiles with the standard derivation less than 0.021 V and the runtime 50 times faster. (2) the parametric relationship between the equivalent circuit model and simplified electrochemical model has been established, which will enhance the comprehension level of two models with more in-depth physical significance and provide new methods for electrochemical model parameter estimation. (3) four simplified electrochemical model parameters: equivalent resistance R eq, effective diffusion coefficient in electrolyte phase D e eff , electrolyte phase volume fraction ε and open circuit voltage (OCV), have been identified by the recursive least square (RLS) algorithm with the modified DST profiles under 45, 25 and 0 °C. The simulation results indicate that the proposed model coupled with RLS algorithm can achieve high accuracy for electrochemical parameter identification in dynamic scenarios.
A mathematical model MICroclimate of GREENhouse (MICGREEN), consisting of set of algebraic equations, was developed. The equations were written for four components of the greenhouse viz. cover, inside air, canopy surface and bare soil surface. It was assumed that the greenhouse air is well mixed, thermal properties of materials of construction do not change with time and solar radiations pass through cover without absorption. The values of dimensions and material properties of the greenhouse constructed at the Research Farm of Department of Soil and Water Engineering, Punjab Agricultural University, Ludhiana were put in these equations. The inputs to the model are ambient air temperature, solar radiations on normal surface, solar radiations on earth's surface, temperature of the soil under canopy and temperature of the soil at a depth of 6cm. A computer program was written in C++ language. The equations were solved using Gauss–Seidal Iteration method. The outputs of the model are greenhouse cover temperature, inside air temperature, canopy temperature and bare soil temperature. The relative humidity of the inside air is predicted from the predicted inside air temperature with the help of psychrometric chart. To validate this model, experiments were conducted on greenhouse to obtain data during winter as tomato crop was being grown. The results of computer model were compared with the experimental results and agreement was found between the measured and predicted values.