batterydata/paper-abstracts huggingface dataset:
The electrochemical characteristics of 1M NaPF6, NaClO4 and NaN(SO2F)2 (i.e., NaFSI) solutions in a quaternary solvent mixture of ethylene carbonate, dimethyl carbonate, propylene carbonate and ethyl acetate, in a 1:1:1:0.5 ratio by volume, were studied for application as electrolytes of supercapacitors working in a wide temperature range (from –40 to 60°C). Mainly microporous carbide derived carbon powder (synthesized from Mo2C by chlorination at 800°C) based electrodes exhibited nearly ideal capacitive behaviour at cell potentials up to 3.4V in the NaPF6 electrolyte, where also the limiting capacitance of 120 F g−1 was practically retained down to –30°C. The slower electrolyte ions diffusion processes at low temperature caused smaller capacitance and inferior power performance for the NaClO4 electrolyte based systems even at room-temperature. Cycle life measurements under floating potential conditions showed that the NaPF6 electrolyte has much better electrochemical stability at 3.0V floating compared to NaClO4. Electrochemical stability problems observed with the NaFSI electrolyte due to oxidation of aluminium current collectors were not overcome by the addition of small concentration of aluminium-stabilizing NaPF6 salt.
Partially fluorinated lithium manganese spinel oxides (LiMn1.8Li0.1Ni0.1O4−x F x ) were prepared by solid-state reaction. Relationship between the electronic structures of LiMn1.8Li0.1Ni0.1O4−x F x and their electrochemical properties were investigated. X-ray absorption near-edge structure (XANES) of Mn K-edge showed that the absorption edge shifted to lower energy with increasing F− content, which indicated decrease of the Mn average oxidation state. Discharge capacity at first cycle was increased by decrease of the Mn average oxidation state with increasing F− content.
Rechargeable magnesium batteries provide the potential for lower cost and improved safety compared with lithium-ion batteries, however obtaining cathode materials with highly reversible Mg-ion capacities is hindered by the high polarizability of divalent Mg-ions and slow solid-state Mg-ion diffusion. We report that incorporating poly(ethylene oxide) (PEO) between the layers of hydrated vanadium pentoxide (V2O5) xerogels results in significantly improved reversible Mg-ion capacities. X-ray diffraction and high resolution transmission electron microscopy show that the interlayer spacing between V2O5 layers was increased by PEO incorporation. Vibrational spectroscopy supports that the polymer interacts with the V2O5 lattice. The V2O5-PEO nanocomposite exhibited a 5-fold enhancement in Mg-ion capacity, improved stability, and improved rate capabilities compared with V2O5 xerogels. The Mg-ion diffusion coefficient of the nanocomposite was increased compared with that of V2O5 xerogels which is attributed to enhanced Mg-ion mobility due to the shielding interaction of PEO with the V2O5 lattice. This study shows that beyond only interlayer spacing, the nature of interlayer interactions of Mg-ions with V2O5, PEO, and H2O are key factors that affect Mg-ion charge transport and storage in layered materials. The design of layered materials with controlled interlayer interactions provides a new approach to develop improved cathodes for magnesium batteries.
The cathode of spent Zn-MnO2 primary batteries is made up of mainly Mn3O4 and α-MnO2. Energy dispersive X-ray analysis of the cathode surface also shows the presence of zinc from the anode and chloride from the electrolyte. Manganese was recovered by precipitation, electrodeposition and anodization. X-ray diffraction measurements confirmed that the Mn3O4 material was recycled by chemical precipitation. The charge efficiency by electrodeposition was 85% at 25.0mAcm−2. In the current density range studied, the potential/current density plots follow a Tafel-like relation. In the anodic process, the material oxidizes at the electrode/solution interface and precipitates to the bottom of the cell. Only a fraction corresponding to 20% of the charge density is deposited onto the electrode. This happens because Mn2+ oxidizes to Mn3+, which then suffers disproportionation.
DNA barcoding is a technique in which species identification is performed using DNA sequences from a small fragment of the genome, with the aim of contributing to a wide range of ecological and conservation studies in which traditional taxonomic identification is not practical. DNA barcoding is well established in animals using the cox1 gene (COI), but there is not yet any proposed universal barcode for plants that has received a broad consensus. We undertook intensive field collections in the renowned Kruger National Park (South Africa), which has its most southern part included in the Maputaland Biodiversity hotspot. Using a selection of trees and shrubs, we compared height potential barcodes: six advised by the plant working group and two from Kress et al. (2007). We applied a battery of metrics to measure intra- and inter-specific genetic divergences, statistical tests, phylogenetic and coalescence analyses. Compared to previous plant studies, we assessed to which extend a ‘DNA barcoding gap’ is present between intra- and inter-specific variations using multiple accessions per species. We identified a portion of the plastid matK gene as a universal DNA barcodes for flowering plants, which can be used singly or in combination with the trnH-psbA inter-gene for a slight increase in performance. Furthermore, we assessed the accuracy of combining to the previous barcode one of the two newly proposed loci by Ki-Joong Kim (University of Seoul). We further discuss the role that DNA barcoding can play in biodiversity inventories for conservation.
F-doped LiFePO4/C nanoparticles were synthesized via a low-temperature hydrothermal reaction followed by high-temperature treatment. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometer, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). To investigate their electrochemical properties, the cyclic voltammetry, electrochemical impedance spectroscopy curves, charge–discharge curves and cycle life test were carried out. The results show that F-doping can modify the microstructure and further improve the electrochemical performance of these cathode materials. These F-doped LiFePO4/C nanoparticles show obviously better high rate performance and stable cycle ability.
We derive and implement analytic solutions for the description of batteries subject to cyclic voltage and current sources of varying amplitudes, consistent with vehicle drive events. An equivalent circuit comprising a resistor in series with a parallel resistor–capacitor combination is employed. The method we develop is applied to a high-power lithium ion cell, thereby allowing us to obtain parameters and overall characteristics useful for (1) representing the battery in system (e.g., vehicle) models and (2) providing a quantitative means of comparing and classifying battery systems. Closed-form analytic solutions derived using Fourier series are compared with experimental data.
Energy storage technologies can provide services to the electricity grid that are necessary for its usability, stability, and reliability. The services, such as power factor correction and renewable energy arbitrage, are defined by duration, cycling occurrence, power, and market price. Storage technologies suitable to these applications, such as pumped hydro and batteries, are defined by their usable energy, power, efficiency, operating range, availability, lifetime, and cost. In this article, grid services and storage technologies are examined using a range of metrics. Through a series of figures and discussions, the reader is provided with a method for comparing universal characteristics with regional/technology specific values. This provides a guiding strategy to help identify overlap between service needs and storage technology capabilities, so as to aid in the specification and selection of systems for present and future grid storage opportunities.
Phosphorus and oxygen co-doped carbon spheres with formaldehyde and resorcinol as precursor were successfully prepared by using phosphoric acid solution as phosphorus source and catalyst. When the pH value of applied phosphoric acid solution is set at 1.38, the spherical carbon materials can be obtained. The corresponding specific surface area can reach 739.48 m2 g−1, and the phosphorus amount can be 0.44 at.%. By contrast, bulk carbon materials were produced when the pH value increased to 3.72. The corresponding specific surface area decreased to 444.3 m2 g−1, and the phosphorus amount declined to 0.10 at.%. It is demonstrated that spherical carbon materials exhibit superior electrochemical performance. The specific capacitance can reach 297.5 F g−1 at the scan rate of 1 mV s−1. Symmetric supercapacitors were constructed with KOH and Na2SO4 as electrolytes, respectively. The specific capacitance can reach 186.8 F g−1 at the current density of 0.1 A g−1 when KOH is used as electrolyte and its energy density can reach up to 50.86 Wh kg−1. However, the stability of the device is relatively poor. In contrast, when sodium sulfate is used as the electrolyte, after 5000 cycles of constant current charge and discharge, the capacity is still 84.09% remaining, exhibiting excellent cycle stability. In addition, the energy density of the device can reach 39.4 Wh kg−1. Even when the power density is 4000 W kg−1, the energy density can still reach 10 Wh kg−1. The obtained materials show great potential for practical application.
The expression analysis of 21BpNACgenes in stem, xylem from different growth season, and tension wood indicated that they might participate in xylem and tension wood development in birch.
Speech deficits, notably those involved in psychomotor retardation, blunted affect, alogia and poverty of content of speech, are pronounced in a wide range of serious mental illnesses (e.g., schizophrenia, unipolar depression, bipolar disorders). The present project evaluated the degree to which these deficits manifest as a function of cognitive resource limitations. We examined natural speech from 52 patients meeting criteria for serious mental illnesses (i.e., severe functional deficits with a concomitant diagnosis of schizophrenia, unipolar and/or bipolar affective disorders) and 30 non-psychiatric controls using a range of objective, computer-based measures tapping speech production (“alogia”), variability (“blunted vocal affect”) and content (“poverty of content of speech”). Subjects produced natural speech during a baseline condition and while engaging in an experimentally-manipulated cognitively-effortful task. For correlational analysis, cognitive ability was measured using a standardized battery. Generally speaking, speech deficits did not differ as a function of SMI diagnosis. However, every speech production and content measure was significantly abnormal in SMI versus control groups. Speech variability measures generally did not differ between groups. For both patients and controls as a group, speech during the cognitively-effortful task was sparser and less rich in content. Relative to controls, patients were abnormal under cognitive load with respect only to average pause length. Correlations between the speech variables and cognitive ability were only significant for this same variable: average pause length. Results suggest that certain speech deficits, notably involving pause length, may manifest as a function of cognitive resource limitations. Implications for treatment, research and assessment are discussed.
Dedicated neuronal circuits enable animals to engage in specific behavioral responses to environmental stimuli. We found that hypoxic stress enhanced gustatory sensory perception via previously unknown circuitry in Caenorhabditis elegans. The hypoxia-inducible transcription factor HIF-1 upregulated serotonin (5-HT) expression in specific sensory neurons that are not normally required for chemosensation. 5-HT subsequently promoted hypoxia-enhanced sensory perception by signaling through the metabotropic G protein–coupled receptor SER-7 in an unusual peripheral neuron, the M4 motor neuron. M4 relayed this information back into the CNS via the FMRFamide-related neuropeptide FLP-21 and its cognate receptor, NPR-1. Thus, physiological detection of hypoxia results in the activation of an additional, previously unrecognized circuit for processing sensory information that is not required for sensory processing under normoxic conditions.
The kinetics of lithium electrochemical systems is governed by the transport processes in the solid electrolyte interphase (SEI) coating the lithium anode. The present work studies the temperature effect on the electrochemical kinetics of a metallic lithium electrode immersed into a LiClO4 solution in propylene carbonate in a wide polarization range. A series of polarization curves of the Li electrode within a temperature range of −35 to +70°C were recorded using the pulse voltammetry method. Any of these symmetrical anodic and cathodic polarization curves looks as a segment of a straight line (the Ohmic current j Ω caused by the intrinsic ionic conductivity of SEI) shading, as the overpotential η rises, into a power curve j inj∝η n (j inj being the injection current) with a temperature-dependent exponent n≥2. Similar polarization curves were recorded for the Li electrode in LiClO4 and LiBF4 solutions in γ-butyrolactone as well. The cause of such a j(η, T) dependence is assumed to be structural disordering of the SEI material resulting in the appearance of a distribution of jump distances and energy barrier height for charge carriers. The stochastic transport of carriers in a disordered solid with a wide distribution of site-to-site jump times leads, by calculation of the current-voltage dependence, to the above power function j inj∝η n with an exponent depending on the absolute temperature T as n=1+(a 1−b 1/T)−2 . Our experimental data are in good agreement with this model. Comparing the experimental j−η curves with the theoretical equations, one could estimate a set of the microscopic parameters of transfer, including the mean jump distance, the effective radius of charge localization, the jumping attempt frequency, and the mean height of energy barriers.
Cross-linkable hyperbranched polymer capped with acryloyl groups (poly-1b) was prepared, and the ionic conductivities and mechanical properties of the composite polymer electrolytes composed of PEO, poly-1b, BaTiO3, and LiN(CF3SO2)2 were investigated in comparison with those of the corresponding composite polymer electrolyte of the non cross-linkable hyperbranched polymer (poly-1a). The cross-linked composite polymer electrolytes of poly-1b showed lower ionic conductivities, but higher tensile strength than the non cross-linked composite polymer electrolyte of poly-1a. This indicates that the cross-linking might improve significantly mechanical property of the composite polymer electrolytes. Addition of tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]boroxine (Bx(3)) to the cross-linked composite polymer electrolyte of poly-1b improved ionic conductivity, transport number, and also interfacial stability between a lithium metal electrode and the composite polymer electrolyte.
In human and animal anesthesia, epidural and spinal administration of drugs is used to provide surgical anesthesia and/or postoperative analgesia. Several local anesthetic drugs are used to produce epidural anesthesia, such as lidocaine, bupivacaine, ropivacaine, and mepivacaine. Epidural analgesia is obtained with opioid agonists, alpha2-adrenergic agonists, and ketamine. In horses, caudal epidural anesthesia is used to desensitize the anus, rectum, perineum, vulva, vagina, urethra, and bladder. The goal is to produce surgical regional anesthesia without losing motor function of the hind limbs. A combination of a local anesthetic drug with an alpha2-adrenergic agonist or an opioid is the most popular option as this combination extends the period of action of the epidural anesthesia or analgesia in horses, humans, and small animals. Spinal analgesia and anesthesia has not been used in horses as an adjunct to general anesthesia as much as it has in small animals and human beings. The epidural administration of opioids with or without local anesthetics is commonly performed in dogs and cats before surgery to reduce general anesthetic requirements as well as to provide intraoperative and postoperative pain control. The perioperative use of epidural and spinal analgesia in horses is likely to increase in the future as recent studies have shown that administration of epidural or subarachnoid alpha2-adrenergic agonists, phencyclidines, opioids, and low-dose local anesthetic produce intense antinociceptive effects.
Disturbances in the default mode network (DMN) have been described in many neurological and psychiatric disorders including Parkinson’s disease (PD). The DMN is characterized by basal activity that increases during rest or passive visual fixation and decreases (“deactivates”) during cognitive tasks. The network is believed to be involved in cognitive processes. We examined the DMN in PD patients on dopaminergic medication with normal cognitive performance compared to age- and gender-matched healthy controls (HC) using fMRI and three methodological procedures: independent component analysis of resting-state data, analysis of deactivation during a complex visual scene-encoding task, and seed-based functional connectivity analysis. In the PD group, we also studied the effect of dopaminergic medication on the DMN integrity. We did not find any difference between the PD and HC groups in the DMN, but using the daily levodopa equivalent dose as a covariate, we observed an enhanced functional connectivity of the DMN in the posterior cingulate cortex and decreased activation in the left parahippocampal gyrus during the cognitive task. We conclude that dopaminergic therapy has a specific effect on both the DMN integrity and task-related brain activations in cognitively unimpaired PD patients, and these effects seem to be dose-dependent.
Surface structural engineering has been widely applied to improve the electrochemical performances of LiCoO2 cathodes, especially for applications at high operation voltages (>4.4 V vs. Li) and elevated working temperature (≥50 °C). In this report, Al2O3 layer with an average thickness of 8 nm was firstly obtained on the LiCoO2 surface, and then was transformed into LiAlO2/LiCo1-xAlxO2 double-layers by a facile heating treatment. This novel double-layers structure was clearly presented by high resolution transmission electron microscopy (HRTEM) and depth profile of X-ray photoelectron spectroscopy (XPS). Due to the chemical/electrochemical stability of the LiAlO2 layer and high Li+ conductivity of the LiCo1-xAlxO2 layer, this cathode with hierarchical structure achieved higher capacity and better cycling stability than the Al2O3 coated LiCoO2 cathode at both 25 and 55 °C. In addition, this LiAlO2/LiCo1-xAlxO2/LiCoO2 cathode maintained the capacity of 178.1 mA h g−1 (73% capacity retention) after 500 cycles (3.0–4.5 V, 1C), which is very promising to be used in severe operation conditions such as high temperature and voltage.
Advanced batteries require careful control over the interfacial properties of their constituent materials. This study designs hierarchically structured cathode materials that are resistant to surface reconstruction, leading to improved cycling performance.
LiFePO4 and Li0.99Nb0.01FePO4 with olivine structure were synthesized by an in situ synthesis technique. Their electrochemical behaviors in Li2SO4 aqueous electrolytes were investigated by cyclic voltammetry (CV). It shows that both compounds undergo lithium ion extraction and intercalation upon oxidation and reverse reduction at the safe potential window without causing the kinetic electrolysis of water. For LiFePO4, only one pair of symmetrical redox peaks, which are associated with the Li+ ion extraction/insertion upon the oxidation/reduction of Fe2+/Fe3+ redox couple, appears on its CV curves at both low (0.10–1.0mVs−1) and medium (5.0–50mVs−1) scan rate ranges. For Li0.99Nb0.01FePO4, various electrochemical behaviors were observed at different scan rate ranges. Two pairs of redox peaks, which are broad and sharp, respectively, appeared at the low scan rate range, but the broad peak pair disappeared at the medium scan rate range. Further study found that the reactions happening at the sharp peak pair are independent of the reactions occurring at the broad one. Various scan rate experiments revealed a linear relationship between the peak current and the square root of scan rate for all peak pairs, indicating that the Li+ deintercalation/intercalation processes occurred in both compounds are diffusion-controlled. The corresponding diffusion coefficients were calculated in the range of 10−11–10−12 cm2 s−1.
Reduced graphene oxide (rGO) supported NiCo2O4 nanobelts with surface pores (NSP-NiCo2O4/rGO) are successfully constructed by means of a combination of a low-temperature hydrothermal method and subsequent calcination. It is found that in the NSP-NiCo2O4/rGO hybrid, the NiCo2O4 nanobelt shows a preferred orientation active (311) plane, which is dotted with abundant pores with an average diameter of ∼4.7 nm. The hybrid is used as a promising anode material for lithium-ion batteries and exhibits a high specific capacity (1324 mAh g−1 at a current density of 0.1 A g−1), excellent rate capabilities (1132, 1066, 993 and 869 mAh g−1 at 200, 300, 500 and 1000 mA g−1, respectively), and a superior cycling stability (only a 4% capacity decay after 80 cycles). The significant Li storage performance of the NSP-NiCo2O4/rGO hybrid is mainly attributed to the unique nanostructure of the NiCo2O4 nanobelt with surface pore and preferred orientation active (311) plane, and the synergistic effect between the NiCo2O4 nanobelts and rGO.
Ag nanoparticles were uniformly deposited on vertically-aligned CuO nanowire arrays (Ag/CuO NWAs) grown on Cu foam. These composite arrays were used as battery-type electrode materials for highly stable hybrid supercapacitors with excellent energy storage performance. Metallic Ag nanoparticles on the surface of CuO NWAs and Ag atoms diffused into the CuO lattice could improve electrical conductivity of the battery-type electrodes by forming a good ohmic contact and by providing positive and stable pathways for the rapid electron/ion transport. Moreover, surface area of Ag/CuO NWAs electrode was also enhanced with additional active sites formed after Ag deposition. Ag/CuO NWAs demonstrated high stored charge of 1481.3 mC cm−2, which is two times higher than pristine CuO NWAs. Our binder-free Ag/CuO NWAs electrode displays excellent stored charge retention of 103% after 10000 cycles at 30 mA cm−2 current density. High-performance hybrid supercapacitor, with Ag/CuO NWAs as the positive electrode and activated carbon as the negative electrode, delivered 0.265 mWh cm−2 energy density, 48 mW cm−2 power density and long lifetime stability. We demonstrated that these hybrid supercapacitors could be randomly interconnected and could power various light-emitting diodes.