batterydata/paper-abstracts huggingface dataset:
0.5Li2MnO3·0.5LiMn1/3Ni1/3Co1/3O2 microspheres are prepared by a slurry spray-drying process (SD-LLO) with subsequent heat treatment. SEM images show that the SD-LLO microspheres are composed of nano-size primary particles. These particles are quite different from conventional LLO microspheres, which are composed of micron-scale plate-like primary particles prepared by a co-precipitation method (CP-LLO). The SD-LLO material experiences a smaller voltage drop during cycling than CP-LLO when used as cathode material in lithium-ion batteries. High-resolution transmission electron microscopy (HR-TEM) and energy dispersive spectroscopy (EDS) indicate that the smaller voltage drop of SD-LLO can be attributed to a more homogeneous distribution of transition metals.
Control of discharge products with respect to composition, size and morphology is of importance to reduce charge potential, suppress side reactions and improve reversibility of Li-O2 batteries, but faces significant challenge due to complicated electrochemical reactions. Here, we report a cathode architecture composed of ZnO nanoparticles anchored on vertically aligned carbon nanotubes (ZnO/VACNTs) that significantly suppresses LiO2 disproportionation, forming the composites of LiO2, Li3O4 and Li2O2 in nanometer size as the final discharge products. The exposed surface of VACNTs provides the electrochemical reaction sites for reducing O2 to O2 −. Transmission electron microscopy measurements in combination with first-principles calculations reveal that the Li2−xO2 compounds nucleated at the interfaces between the ZnO and the VACNTs are stabilized by the nanosize effect (in the scale of 6nm), which is related to the semiconductive behavior of ZnO. This discharge chemistry leads to the reduced charge overpotential and extended cycle life. The results here demonstrate that the electrochemical reaction tuned by the cathode architecture is a powerful tool to improve Li-O2 cell performance.
A new procedure for the electrosynthesis of polyaniline (PANI), based on the electropolymerization of aniline on a PANI-modified electrode, is proposed. The procedure is controlled by the chemical reaction between the aniline and the highest oxidized form of PANI. A spectroelectrochemical flow cell has been used to study the influence of the flow rate on this process, which has enabled direct observation of the autocatalytic mechanism. Unexpectedly, the hydrodynamic conditions do not seem to have an effect on the resulting polymer film. Similar results were obtained by carrying out the electropolymerization in nitric and perchloric acid.
Potential applications of sodium-ion batteries (SIBs) have motivated significant research interest in grid-scale energy storage. However, large radius of Na ions results in different electrochemical behaves. Therefore, synergistic understanding of the differences is greatly interested for future development of SIBs. Surface availability for ions with poor affinity to electrode materials is critical to rate performance in SIBs, but yet has rarely been reported. Here, to overcome the obstacles of material platform, amorphous TiO2 inverse opal is employed as a proof-of-concept prototype to illuminate the effects of surface ion availability and its relationship between solvent wettability and rate capability. Within expectation, superior rate capabilities are achieved in return for enhanced solvent wettability, regardless of the type of electrolyte and the ion concentration in electrolyte. Even when the anode is cycled at a current density as high as 5000mAg−1, the reversible capacity could still retain a high value of ~113mAhg−1. Our concept opens up a promising avenue to realize full potential of designing electrode materials for SIBs by adjusting the surface kinetics. This understanding shall extend the design principle to electrode materials for highly effective energy storage using other transport ions and other storage mechanisms.
The use of medicinal plants is an increasing phenomenon among the majority of people in many developing countries. Some of the harvested medicinal plants are often stored for shorter or longer periods prior to usage. Evidence from recent studies has demonstrated the pharmacological efficacy of short and long-term stored plant materials when compared to freshly-harvested ones. In an attempt to evaluate the effect of long-term storage on the safety of some commonly used medicinal plants, the Ames test which involved the use of three Salmonella typhimurium tester strains (TA98, TA100 and TA1535) were conducted. Current findings indicate the absence of any mutagenic effects resulting from the storage of medicinal plant materials for as long as 16years. Although freshly collected Acokanthera oppositifolia extract demonstrated a mutagenic effect against TA1535 strain at the highest concentration tested, no such effect was observed in the stored material. Further studies involving metabolic activation systems and in vivo conditions may further elucidate the effect of long-term storage on the safety of medicinal plants.
This paper is devoted to the development of a new lead acid battery electrolyte formulation for cycling applications, especially for renewable energy markets in developing countries. These emerging markets, such as solar home systems, require lead acid batteries at very low prices and improved performances compared to automotive batteries produced locally. The new acid formulation developed is a mixture of sulphuric acid, liquid colloidal silica and other additives including phosphoric acid. The colloidal silica is used at a low concentration in order to decrease the acid stratification process during cycling at high depth of discharge. Phosphoric acid is used for the improvement of the textural evolution of the positive active material during cycling. After a description of the markets and of the additives used in the new acid formulation, this paper presents the results obtained with normalised photovoltaic cycle testing on low cost automotive batteries modified by the new electrolyte formulation. It is shown that the cycling life of such batteries is much increased in the presence of the new formulation. These results are explained by the improved evolution of positive active mass softening parameters (specific surface and β-PbO2 crystallite size) and also by a more homogeneous sulphating process on both plates.
The multilayer films consisting of active (Si) and inactive (Fe) metal elements were investigated as anodes for lithium rechargeable batteries. It has been revealed that the electrochemical performance of as-deposited Fe/Si multilayer films could be improved and optimized by controlling the multilayer structure like the thickness and number of stacked layers as well as post-annealing treatment. It appears that the adhesion between Si film and current collecting substrate is critical for attaining a prolonged cycling stability, which can be effectively achieved by insertion of an adhesion-promoting layer selected based on the chemical affinity between the constituent elements at a given interface. Fe/Si multilayer film electrodes have shown acceptable electrochemical properties as an anode material.
A new fire retardant-dimethyl methyl phosphate (DMMP) was tested as a nonflammable electrolyte solvent for Li-ion batteries. It is found that in the addition of chloro-ethylene carbonate (Cl-EC) as an electrolyte additive, the electrochemical reduction of DMMP molecules can be completely suppressed and the graphite anode can be cycled very well with high initial columbic efficiency (∼84%) and excellent cycling stability in the DMMP electrolyte. The prismatic C/LiCoO2 batteries using 1.0molL−1 LiClO4 +10% Cl-EC+DMMP electrolyte exhibited almost the same charge and discharge performances as those using conventional carbonate electrolytes, suggesting a feasible use of this new electrolyte for constructing nonflammable Li+-ion batteries.
Aim The purpose of the study was to explore the test–retest reliability and minimal detectable change of selected functional fitness test items in adults with Down syndrome. Methods Forty-three adults with Down syndrome (24 men and 19 women) aged 18–50 years completed a battery of tests twice in a two-week period. The battery of tests consisted of two balance items, two flexibility items, five muscular strength and endurance items, two aerobic items, and one functional task. All items were considered valid and reliable tests in a general elderly or intellectually disabled population. The test–retest relative reliability for all repeated tests was assessed with intraclass correlation coefficient performing one-way analysis of variance. The test–retest absolute variability was measured by using the standard error of measurement (SEM) to calculate the minimal detectable change at the 90% confidence interval (MDC90). Reliability data was visualised with a Bland–Altman plot. Results All tests showed excellent intraclass correlation coefficients (ICC's>0.9). All SEM values demonstrated acceptable measurement precision (SEM<SD/2). Values for MDC90 are provided for all 12 tests. The analyses indicated that there was no major systematic bias in the plots. The scatter around the Bland–Altman was distributed randomly. Conclusion All twelve functional fitness tests demonstrated adequate feasibility and relative and absolute test–retest reliability in adults with Down syndrome in South Africa. Information of this nature will help to monitor performance alterations over time and success of training interventions.
Superlattice arrays, an important type of nanomaterials, have wide applications in catalysis, optic/electronics and energy storage for the synergetic effects determined by both individual metals and collective interactions. Herein, a simple one-pot solvothermal coreduction approach is developed for facile preparation of bimetallic PtAu alloyed superlattice arrays (PtAu SLAs) in oleylamine, with the assistance of urea via hydrogen bonding induced self-assembly. Urea is essential in morphology-controlled process and prevents PtAu nanoparticles from the disordered aggregation. The characterization and formation mechanism of PtAu SLAs are investigated in details. The as-synthesized hybrid nanocrystals exhibit enhanced electrocatalytic performances for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in alkaline electrolyte in comparison with commercial Pt-C (50%, wt.%) and Pt black catalysts.
This study utilizes computational topology optimization methods for the systematic design of optimal multifunctional silicon anode structures for lithium-ion batteries. In order to develop next generation high performance lithium-ion batteries, key design challenges relating to the silicon anode structure must be addressed, namely the lithiation-induced mechanical degradation and the low intrinsic electrical conductivity of silicon. As such this work considers two design objectives, the first being minimum compliance under design dependent volume expansion, and the second maximum electrical conduction through the structure, both of which are subject to a constraint on material volume. Density-based topology optimization methods are employed in conjunction with regularization techniques, a continuation scheme, and mathematical programming methods. The objectives are first considered individually, during which the influence of the minimum structural feature size and prescribed volume fraction are investigated. The methodology is subsequently extended to a bi-objective formulation to simultaneously address both the structural and conduction design criteria. The weighted sum method is used to derive the Pareto fronts, which demonstrate a clear trade-off between the competing design objectives. A rigid frame structure was found to be an excellent compromise between the structural and conduction design criteria, providing both the required structural rigidity and direct conduction pathways. The developments and results presented in this work provide a foundation for the informed design and development of silicon anode structures for high performance lithium-ion batteries.
Two novel methods to estimate the state of charge (SOC) and state of health (SOH) of a lithium-ion battery are presented. Based on a detailed deduction, a dual filter consisting of an interaction of a standard Kalman filter and an Unscented Kalman filter is proposed in order to predict internal battery states. In addition, a support vector machine (SVM) algorithm is implemented and coupled with the dual filter. Both methods are verified and validated by cell measurements in form of cycle profiles as well as storage and cycle ageing tests. A SOC estimation error below 1% and accurate resistance determination are presented.
While egg-bearing (ovigerous) American lobsters are found in estuaries, it is not known if they are present when their eggs hatch. The major goal of this study was to test the hypothesis that a portion of the larvae that serve as new recruits to the Great Bay Estuary lobster population originate from females that are year-around residents. First, a total of nine ovigerous lobsters were fitted with acoustic transmitters and tracked from October through the following spring-to-early summer. We found that all lobsters overwintered in the estuary and were located again within 1 km of their fall positions the following May–June, when their eggs likely hatched. Second, sea sampling surveys carried out in the spring revealed that ovigerous lobsters in the estuary were carrying more developed eggs than their coastal counterparts. Third, through a series of laboratory-based studies, we calculated the putative hatch dates of egg clutches carried by estuarine and coastal lobsters and show that estuarine lobster eggs likely hatch 2–3 weeks earlier than eggs carried by coastal females. Finally, plankton tow surveys in the estuary revealed that stage I larval lobsters (zoeae) were present in the estuary from May to July, which encompasses the predicted hatching period for both estuarine and coastal eggs. Therefore, new recruits to the Great Bay Estuary lobster population likely come from both resident estuarine lobsters and coastal females.
A design for an air-breathing and passive polymer electrolyte fuel cell is presented. Such a type of fuel cell is in general promising for portable electronics. In the present design, the anode current collector is made of a thin copper foil. The foil is provided with an adhesive and conductive coating, which firstly tightens the hydrogen compartment without mask or clamping pressure, and secondly secures a good electronic contact between the anode backing and the current collector. The cathode comprises a backing, a gold-plated stainless steel mesh and a current collector cut out from a printed circuit board. Three geometries for the cathode current collector were evaluated. Single cells with an active area of 2cm2 yielded a peak power of 250–300mWcm−2 with air and pure H2 in a complete passive mode except for the controlled flow of H2. The cells’ response was investigated in steady state and transient modes.
Water desalination is increasingly becoming a competitive solution for providing drinking-water in many countries around the world. The desalination of saline water has been recognized as one of the most sustainable and new water resource alternative. It plays a crucial role in the socio-economic development for many communities and industrial sectors. Currently there are more than 14,000 desalination plants in operation worldwide producing several billion gallons of water per day. Fifty-seven percent are in the Middle East and Gulf region where large scale conventional heat and power plants are installed. However, since they are operated using fossil fuels, they are becoming expensive to operate and the pollution and greenhouse gas emissions they produce are increasingly recognized as harmful to the environment. Moreover, such plants are not economically viable in remote areas, even in coastal regions where seawater is abundant. Many areas often experience a shortage of fossil fuels and inadequate and unreliable electricity supply. The integration of renewable energy resources in desalination and water purification is becoming more viable as costs of conventional systems increase, commitments to reducing greenhouse gas emissions are implemented and targets for exploiting renewable energy are set. Thus, solar energy could provide a sustainable alternative to drive the desalination plants, especially in countries which lie on the solar belt such as Africa, the Middle East, India, and China. This paper explores the challenges and opportunities of solar water desalination worldwide. It presents an extensive review of water desalination and solar desalination technologies that have been developed in recent years and the state-of-the-art for most important efforts in the field of desalination by using solar energy, including the economic and environmental aspects.
In order to significantly enhance the elevated-temperature performance of LiSi0.05Mg0.05Mn1.90O4, the LiAlxSi0.05Mg0.05Mn1.90-xO4 (0≤x≤0.08) samples were firstly prepared via sol-gel technique. All the obtained samples showed the intrinsic spinel structure without any other detectable impurity phases. Among these samples, the LiAl0.05Si0.05Mg0.05Mn1.85O4 sample was found to be optimal possessing regular crystal morphology with clean surfaces and presented much better elevated-temperature cycling stability and rate capability. When carried out at 55°C, the LiAl0.05Si0.05Mg0.05Mn1.85O4 sample exhibited the initial discharge capacity of 123.6mAhg−1 at 0.5C between 3.20 and 4.35V. After 100 cycles, the discharge capacity could still reach up to 115.9mAhg−1 with capacity retention of 93.8%, which was much higher than that of LiSi0.05Mg0.05Mn1.90O4. At the higher discharge rate of 10C, a high discharge capacity of 82.5mAhg−1 could be obtained with capacity retention of 95.6% after 50 cycles at 55°C. By contrast, the LiSi0.05Mg0.05Mn1.90O4 sample only exhibited 43.7mAhg−1 with lower capacity retention of 61.8%. These results indicate that the introduction of appropriate amount of aluminium ions in the magnesium and silicon co-doped spinel can make up for the shortage of co-doping with magnesium and silicon ions in term of the elevated-temperature performance.
The aggregation of multiple metrics of corporate social performance (CSP) poses one of the major problems in CSP research. In this paper we propose a new method to compute a composite indicator of CSP from an efficiency perspective using data envelopment analysis. The new approach makes it possible to appropriately account for both positive and negative aspects of CSP, and also to measure CSP for firms for which some of the metrics are exhibiting zero values. Within the new method, we propose measuring global (metafrontier) CSP inefficiency with regard to all firms in the sample and decomposing it into within-industry CSP inefficiency measured with regard to own industry group and industry gap CSP inefficiency. In this way, we measure inefficiencies due to shortcomings in managerial practices and due to the differences between industries in relation to CSP. Using a sample of United States firms in a variety of economic sectors from 2004 to 2015, as covered by the Kinder, Lydenberg and Domini database, we find considerable potential for improvement in CSP practices, with the most CSP-efficient firms representing mining and manufacturing sectors, and the most inefficient belonging to the construction sector. We also find that CSP inefficiency dropped in the period related to the recent financial crisis.
In this work, three dimensional Co9S8 nanorod@Ni(OH)2 nanosheet core-shell structure is directly fabricated on flexible carbon cloth by a simple low temperature hydrothermal method. This structure with good electrochemical performance could be applied for supercapacitor electrode material. Firstly, this three dimensional structure possesses high specific capacitance of 1620 F g−1, which is 1.7 times of the specific capacitance of the pure Ni(OH)2 electrode and 2.5 times of that of the pure Co9S8 electrode. Secondly, this hybrid electrode exhibits a very high energy density of 70.0 Wh Kg−1 at the power density of 305.7 W kg−1. In addition, the hybrid electrode displays good cycling stability with 104.5% of the initial capacitance after 2000 continuous cycles. Furthermore, the hybrid electrode with three dimensional structure possesses excellent flexibility and has almost the same cyclic voltammetry curve under different bending angles. Thus, the designed electrode holds great promises for light weight, flexible, high energy density supercapacitor applications.
Solid electrolyte Li7La3Zr2-x Ti x O12 (x =0, 0.1, 0.2, 0.3, 0.4 and 0.5) ceramics have been prepared via a conventional solid-state reaction. X-ray diffraction (XRD) analysis confirms that all samples formed a single phase with cubic garnet structure within the limit of instrument measurement, and with increasing Ti content from x =0 to 0.5, the intensity of diffraction peaks exhibits a tendency of weakening. It is found that Ti doping in Li7La3Zr2O12 (LLZ) can lead to the increase of the densification, which is favorable to improve the ionic conductivity. Finally, optimized conductivity has been obtained for the sample with x =0.3 for lithium ion battery: the total ionic conductivity reaches a maximum of about 4.16×10−4 Scm−1 at 30°C with an activation energy of about 0.48eV. XRD analysis and cyclic voltammetry experiments on cells indicate the Li7La3Zr2-x Ti x O12 pellet is stable with lithium metal.
Bismuth is considered to be a detrimental element to lead–acid batteries because it has lower hydrogen evolution overpotential than lead. On the other hand, bismuth can improve the performances of negative or positive active-materials. It is necessary to understand the performance of bismuth in sulfuric acid solution in order to reduce its detrimental effect on lead–acid batteries and make good use of its beneficial aspects. In this paper, the electrochemical behaviour of bismuth in sulfuric acid solution is studied by cyclic voltammetry (CV), chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), scanning electronic spectroscopy (SEM), and X-ray diffraction (XRD). At potentials near close to the open-circuit value bismuth dissolves actively when it is anodized. As the potential increases, two oxidation peaks are observed. The first peak corresponds to the formation of bismuth sulfate, that follows a dissolution–precipitation mechanism and suppresses the dissolution of bismuth. The second peak due to secondary oxidation of bismuth under the bismuth sulfate film. There is a large current plateau at higher potentials this involves the dissolution of bismuth sulfate into solution, the formation of bismuth sulfate from bismuth oxide, and the formation of bismuth oxide from matrix bismuth. Hydrogen evolution takes place on bismuth just after the potential where the reduction of lead sulfate is completed. Oxygen evolution cannot occur on bismuth covered with bismuth sulfate.