batterydata/paper-abstracts huggingface dataset:
We report a controllable, low-cost and large-scale synthesis protocol for foam-like, 3-dimension mesopore N-doped carbon assembling TiO2 nanoparticles (P25). The process uses common P25 as raw material, PVP as dispersing agent and binder as well as carbon precursor, boiling bubbles as template, solidifying the boiling foam by PVP-coating-and-connecting TiO2 nanoparticles. The carbonization transforms PVP-assembling to carbon-assembling, and the obtained carbon is doped by a little N, which endows the carbon with higher conductivity. It is found that the synthesized material possesses abundant mesopores, individual nanoparticles-assembled structure and high conductive N-doped carbon matrix; shows large specific surface area and pore volume. As anode material for lithium-ion batteries (LIBs), foam-like P25 exhibits superior lithium storage properties with high discharge capacity, stable cycling performance and excellent rate capability. At 1C, foam-like P25 delivers discharge capacity of 223.1 mAh g−1 at the 200th cycle, and average discharge capacity over 200 cycles reaches 227 mAh g−1. These excellent electrochemical properties should be attributed to the unique foam-like mesoporous structure that greatly improves lithium storage properties of common P25, especially enhances pseudocapacitive interfacial storage of P25. The synthetic method has great potential for large scale production of foam-like P25 for practical application in high-performance LIBs.
Motivated by the potential of using room temperature ionic liquids (RTILs) as electrolytes to replace traditional aqueous electrolytes for Zn-anode secondary batteries, Zn/Zn(II) redox reactions have been studied in four aprotic RTILs based on pyrrolidinium ([Pyrr]+) and imidazolium ([Im]+) cations, and bis(trifluoromethanesulfonyl)imide ([TFSI]−) and dicyanamide ([DCA]−) anions. Cyclic voltammetry results suggest a smaller overpotential for Zn redox in [Im]+ cation based and [DCA]− anion based RTILs than in [Pyrr]+ and [TFSI]− based RTILs. Potentiodynamic polarization experiments indicate a strong dependence of the electrode reaction mechanism for the Zn species on the RTIL anions. In [TFSI]− based RTILs, Zn2+ ions are the electroactive species, with the electrode reaction being a single-step, two-electron transfer process. In [DCA]− based RTILs, two-step, single-electron reactions account for the electrode mechanism. The exchange current densities derived from Tafel analysis for the Zn species in the four RTILs are greater than 10−3 mA/cm2, with the [Im]+ cation based RTIL possessing the highest value of 9.9×10−3 mA/cm2. The results obtained will assist in obtaining a better understanding of the electrochemical behavior of Zn in RTILs, shedding light on the development of RTILs for Zn-anode secondary batteries.
Porous polybenzimidazole membranes with ultra-high selectivity and stability were designed and fabricated for vanadium flow batteries. The combination of the facile fabrication procedure, high performance, the low cost of the starting materials and easy up-scaling makes the PBI porous membrane currently by far the most promising candidate for vanadium flow batteries.
Objectives Our recent pilot study demonstrated mindfulness-based cognitive therapy (MBCT) is a potentially efficacious headache pain treatment; however, it was not universally effective for all participants. This study sought to explore patient characteristics associated with MBCT treatment response and the potential processes of change that allowed treatment responders to improve and that were potentially lacking in the non-responders. Design We implemented a mixed-methods analysis of quantitative and qualitative data. The sample consisted of 21 participants, 14 of whom were classified as treatment responders (≥50% improvement in pain intensity and/or pain interference) and seven as non-responders (<50% improvement). Setting The study was conducted at the Kilgo Headache Clinic and the University of Alabama Psychology Clinic. Intervention Participants completed an 8-week MBCT treatment for headache pain management. Measures Standardized measures of pain, psychosocial outcomes, and non-specific therapy factors were obtained; all participants completed a post-treatment semi-structured interview. Results Quantitative data indicated a large effect size difference between responders and non-responders for pre- to post-treatment change in standardized measures of pain acceptance and catastrophizing, and a small to medium effect size differences on treatment dose indicators. Both groups showed improved psychosocial outcomes. Qualitatively, change in cognitive processes was a more salient qualitative theme within treatment responders; both groups commented on the importance of non-specific therapeutic factors. Barriers to mindfulness meditation were also commented on by participants across groups. Conclusions Results indicated that change in pain related cognitions during an MBCT intervention for headache pain is a key factor underlying treatment response.
There are many guidelines available concerning the treatment of Parkinson’s disease. Most of these advocate treating young-onset patients with a dopamine agonist and older patients with levodopa. The rationale behind this recommendation has its origins in the side effects associated with each of these drug classes: whilst levodopa leads to dyskinesia, which may not be relevant for patients with a limited life-expectancy, dopamine agonists have a much longer plasma half life which probably leads to more continuous dopamine receptor stimulation and thus decreases the occurrence and severity of dyskinesia. However, the side effects associated with the use of dopamine agonists, such as sleepiness, orthostatic problems, hallucinations and impulse control disorders are a drawback. In this overview, the hypothesis will be put forward that perhaps such a strict distinction is no longer needed. A new idea may be the early combination of levodopa with a dopamine agonist which would provide good clinical efficacy and, because of the relatively low doses involved, would reduce the side effects associated with both substances. MAO-B inhibitors may be a good option for early treatment and especially for patients who experience first motor fluctuations. Similarly, and particularly if a wearing-off symptom is present, COMT inhibitors smoothen and prolong the action of levodopa. More invasive escalation therapy comes into play when patients reach the advanced stages with problems of insufficient motor control, such as bradykinesia, rigidity and resting tremor, combined with on-time dyskinesia. The use of all oral and invasive treatment has to be individualized to gain a good motor and non-motor control and especially a good quality of life.
In recent years, much effort has been dedicated to achieve lightweight, stretchable and flexible energy-storage devices for wearable electronics. Here we report an everyday cotton fabric coated with poly(pyrrole) as flexible electrodes. Poly(pyrrole) nanoparticles are synthesized on the fabrics via a simple chemical polymerization process with the mixed surfactants of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl benzene sulfonate (SDBS) as soft template. A highly conductive fabric with surface resistance of 14Ω/□ can be produced by changing surfactant concentration. Such a conductive textile shows outstanding flexibility and stretchability, and demonstrates strong adhesion between the PPy and the cellulose fiber. The fabric electrode exhibits a discharge capacity of 51.7mAhg−1 with high cycling stability (negligible decay after 100 cycles).
Currently, renewable and low-cost electrode materials are being intensively pursued to meet the development of sustainable electrochemical energy-storage systems. Chitin, which is the second most abundant biopolymer throughout the natural world and can be sourced cheaply from the exoskeletons of arthropods and shells of cephalopods, has many attractive properties such as renewability, nontoxicity, intrinsically fibrous structure and high nitrogen content. In this study, nitrogen-doped amorphous carbon nanofibers (NACF) fabricated by direct pyrolysis of chitin, were used as the anode material in sodium-ion batteries (SIBs) for the first time. The NACF electrode delivered a high reversible capacity of 320.6mAhg−1 with excellent rate capability and long cyclability. The superior electrochemical performance can mainly be attributed to synergistic effects of the unique one-dimensional mesoporous nanofibers facilitating the transmission of electrons/electrolyte, and the N-doped amorphous nanostructure increasing electrical conductivity and number of active sites. Furthermore, a sodium-ion full cell was constructed by coupling the NACF electrode with a Prussian blue cathode, and it delivered 115mAhg−1 while retaining 90% of the capacity after 200 cycles. Our work will hopefully inspire the research community to explore other advanced materials with value-added attributes that can be generated by appropriate treatment of renewable bio-waste.
The work of John Milne, the centenary of whose death is marked in 2013, has had a large impact in the development in global seismology. On his return from Japan to England in 1895, he established for the first time a global earthquake recording network, centred on his observatory at Shide, Isle of Wight. His composite bulletins, the “Shide Circulars” developed, in the twentieth century, into the world earthquake bulletins of the International Seismological Summary and eventually the International Seismological Centre, which continues to publish the definitive earthquake parameters of world earthquakes on a monthly basis. In fact, seismology has a long tradition in Britain, stretching back to early investigations by members of the Royal Society after 1660. Investigations in Scotland in the early 1840s led to a number of firsts, including the first network of instruments, the first seismic bulletin, and indeed, the first use of the word “seismometer”, from which words like “seismology” are a back-formation. This paper will present a chronological survey of the development of seismology in the British Isles, from the first written observations of local earthquakes in the seventh century, and the first theoretical writing on earthquakes in the twelfth century, up to the monitoring of earthquakes in Britain in the present day.
In the past several years, there have been many developments in the materials for lead–acid batteries. Silver in grid alloys for high temperature climates in SLI batteries has increased the silver content of the recycled lead stream. Concern about silver and other contaminants in lead for the active material for VRLA batteries led to the initiation of a study by ALABC at CSIRO. The study evaluated the effects of many different impurities on the hydrogen and oxygen evolution currents in float service for flooded and VRLA batteries at different temperatures and potentials. The study results increased the understanding about the effects of various impurities in lead for use in active material, as well as possible performance and life improvements in VRLA batteries. Some elements thought to be detrimental have been found to be beneficial. Studies have now uncovered the effects of the beneficial elements as well as additives to both the positive and negative active material in increasing battery capacity, extending life and improving recharge. Glass separator materials have also been re-examined in light of the impurities study. Old glass compositions may be revived to give improved battery performance via compositional changes to the glass chemistry. This paper reviews these new developments and outline suggestions for improved battery performance based on unique impurities and additives.
Three-dimensional reduced graphene oxides hydrogel anchored with ultrafine CoO nanoparticles (CoO/RGO nanocomposite) is prepared by a facile hydrothermal strategy and subsequently heat-treatment process. The small-size CoO nanoparticles are encapsulated within graphene-based hydrogel with robust interconnected networks for the CoO/RGO nanocomposite. The electrochemical performances are evaluated by using coin-type cells. It delivers high rate capacities of 890.2, 690.4, 543.8 and 457.0mAhg−1, even at 200, 800, 1600 and 2400mAg−1, respectively. The specific capacity increases to 1025.8mAhg−1 after 82 cycles when the current density is back to 100mAg−1, indicating excellent rate capability and cycle stability. The improved electrochemical performance is ascribed to the fabricated structure with three-dimensional RGO nanosheets. The CoO/RGO nanocomposite will be a promising candidate of anode material for lithium ion batteries.
Microspheres composed of multilayer graphene (MMG) had been prepared by the chemical reduction of graphene oxide at 100°C. The morphology, structure and electrochemical performance of MMG as anode material for lithium-ion batteries were investigated by high-resolution transmission electron microscope, scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical testing techniques. It is found that the specific capacity of MMG (453mAhg−1) is almost twice that of multilayer graphene (MG, 229mAhg−1). Furthermore, MMG exhibits good cycle performance and high-rate charge/discharge properties.
The purpose of this study was to evaluate the overall sensitivity and applicability of a number of bioassays representing multiple trophic levels, for the preliminary ecotoxicological screening (Tier I) of estuarine sediments. Chemical analyses were conducted on sediments from all sampling sites to assist in interpreting results. As sediment is an inherently complex, heterogeneous geological matrix, the toxicity associated with different exposure routes (solid, porewater and elutriate phases) was also assessed. A stimulatory response was detected following exposure of some sediment phases to both the Microtox® and algal bioassays. Of the bioassays and endpoints employed in this study, the algal test was the most responsive to both elutriates and porewaters. Salinity controls, which corresponded to the salinity of the neat porewater samples, were found to have significant effects on the growth of the algae. To our knowledge, this is the first report of the inclusion of a salinity control in algal toxicity tests, the results of which emphasise the importance of incorporating appropriate controls in experimental design. While differential responses were observed, the site characterised as the most polluted on the basis of chemical analysis was consistently ranked the most toxic with all test species and all test phases. In terms of identifying appropriate Tier I screening tests for sediments, this study demonstrated both the Microtox® and algal bioassays to be more sensitive than the bacterial enzyme assays and the invertebrate lethality assay employing Artemia salina. The findings of this study highlight that salinity effects and geophysical properties need to be taken into account when interpreting the results of the bioassays.
Sulfur (S) encapsulated in porous carbon nanofibers (CNFs) was synthesized viaelectrospinning, carbonization and solution-based chemical reaction–deposition method. The chemical reaction–deposition strategy provides intimate contact between the S and the CNFs. This would not necessarily be the case for other reported methods, such as ball milling and thermal treatment. These novel porous carbon nanofiber–sulfur (CNF–S) nanocomposites with various S loadings showed high reversible capacity, good discharge capacity retention and enhanced rate capability when they were used as cathodes in rechargeable Li/S cells. We demonstrated here that an electrode prepared from a porous CNF–S nanocomposite with 42 wt% S maintains a stable discharge capacity of about 1400 mA h g−1 at 0.05 C, 1100 mA h g−1 at 0.1 C and 900 mA h g−1 at 0.2 C. We attribute the good electrochemical performance to the high electrical conductivity and the extremely high surface area of the CNFs that homogeneously disperse and immobilize S on their porous structures, alleviating the polysulfide shuttle phenomenon. SEM measurements showed that the porous CNF structures remained nearly unchanged even after 30 cycles' discharging/charging at 0.05 C.
In this work, a naphthalene tetracarboxylic acid lithium salt (NTCLi) as anode material is designed for lithium-ion batteries, with high theoretical capacity and conjugated system according to the combination principles of multi-carboxyl groups and low molecular weight, which is prepared through a simple one-pot neutralization reaction. The sample is characterized by SEM, TEM, XRD, IR and TGA. The results show that NTCLi exhibits nanorod-like structure, well thermal stability and crystalline structure. The electrochemical measurements results demonstrate the initial discharge capacity of 276mAhg−1 with low discharge platform (~0.9V) at the current density of 0.1C are achieved for NTCLi, and the discharge specific capacity of 190mAhg−1 can be retained after 100 cycles. Also, NTCLi delivers good rate capability with discharge capacity of up to 112mAhg−1, even at a current density as high as 2C, indicating the as-prepared sample could be a promising candidate as anode materials for lithium-ion batteries.
Electrode materials that combine the high energy density of batteries and the high power density of supercapacitors become an increasing need for current and near-future applications. Ta2O5 delivers a high theoretical capacity but suffers from unsatisfactory rate capabilities. Here we prepare a structurally disordered Ta2O5 nanoparticle aerogel via a nonaqueous sol-gel process followed by CO2 super-critical drying. The resulting aerogels exhibit large surface area, high porosity, fast ion diffusion, and extrinsically pseudocapacitive Li+/Na+ storage behavior (through surface redox reactions). With these merits, when evaluated as anode material for both lithium-ion and sodium-ion half cells (LIBs and NIBs), the Ta2O5 aerogels show excellent rate capabilities (97.0 and 43.7 mA h g−1 at 5000 mA g−1 for LIBs and NIBs, respectively) and highly stable cycling performance (20000 cycles at 5000 mA g−1 and 10000 cycles at 1000 mA g−1 without obvious capacity fading for LIBs and NIBs, respectively). This work introduces Ta2O5, a typical conversion-type metal oxide without intrinsic pseudocapacitance, as a promising anode material with high extrinsic pseudocapacitance for both LIBs and NIBs, which may open the door to achieve high-rate alkali-ion storage with low synthesis cost for durable microbatteries.
Local inhomogeneous electrode utilization in recent lithium-ion batteries tends to increase due to larger sizes and/or higher densification, which poses a challenge for accurate, model-based monitoring. Pseudo-two dimensional (p2D) physicochemical models (PCM) can offer such locality via calculating local potentials and concentrations through the thickness of the electrode stack and are numerically reduced for implementation in a microcontroller in this work. Finite difference method combined with solid-diffusion approximations and orthogonal collocation reformulation are applied to generate three MATLAB- and three microcontroller-suitable C-code p2D-PCMs, which are experimentally validated towards constant current charge/discharge and driving cycle loads on a high-energy NMC-811/SiC-18650 lithium-ion battery. Benchmarking to an equivalent circuit model reveals similar mean cell voltage errors below 20 mV for the driving cycle. Reducing spatial elements reveals errors below 1% for local (i.e. concentrations/potentials) and global states (i.e. cell voltage/temperature) and is applied to speed-up the C-code p2D-PCMs in the microcontroller (max. 168 MHz with 192 kB RAM) to calculate at least 37% faster than real-time. Real-time computability is investigated via varying processor frequencies and using hardware acceleration schemes. The memory allocation to solve and store the p2D-PCMs on the microcontroller require 115 kB and 213 kB at a maximum, respectively.
In this study, a novel facile and rapid method to prepare three-dimensional (3D) flower-like CoS hierarchitectures by microwave assisted heating has been developed. The 3D flower-like CoS architectures are constructed by two-dimensional nanopetals intertwined with each other and the formation mechanism are studied. The pseudo-capacitive properties of the CoS material are evaluated by cyclic voltammetry and galvanostatic charge-discharge tests in 6M KOH solution. A specific capacitance of 586 F g−1 is obtained at a charge-discharge current density of 1 A g−1. The CoS nanostructure exhibits excellent cycling stability and it maintains 91% of its initial specific capacitance after 1000 cycles. It also exhibits excellent rate capability, improved energy density and power density.
Many technically relevant materials are non-homogeneous in structure. Their investigation requires a locally resolved surface analysis. An exact determination of the accessed area and a potentiostatic control in a three-electrode configuration are necessary. This becomes possible by capillary-based microcells which enable local impedance measurements and even impedance mapping of the surface. Different aspects and strategies of this microimpedance spectroscopy are presented and discussed, together with some examples.
This paper addresses the annual energy storage requirements of small islanded electricity systems with wind and photovoltaic (PV) generation, using hourly demand and resource data for a range of locations in New Zealand. Normalised storage capacities with respect to annual demand for six locations with winter-peaking demand profiles were lower for wind generation than for PV generation, with an average PV:wind storage ratio of 1.768:1. For two summer-peaking demand profiles, normalised storage capacities were lower for PV generation, with storage ratios of 0.613:1 and 0.455:1. When the sensitivity of storage was modelled for winter-peaking demand profiles, average storage ratios were reduced. Hybrid wind/PV systems had lower storage capacity requirements than for wind generation alone for two locations. Peak power for storage charging was generally greater with PV generation than with wind generation, and peak charging power increased for the hybrid systems. The results are compared with those for country-scale electricity systems, and measures for minimising storage capacity are discussed. It is proposed that modelling of storage capacity requirements should be included in the design process at the earliest possible stage, and that new policy settings may be required to facilitate a transition to energy storage in fully renewable electricity systems.