batterydata/paper-abstracts huggingface dataset:
High performance of lithium ion batteries (LIBs) relies largely on scrupulous design of bespoke active materials. Herein, we report a facile controllable electrospinning method for preparation of Co3O4 nanotubes with diameters of 200–300nm. The obtained Co3O4 nanotubes are composed of interconnected nanoparticles of 20–40nm and show polycrystalline feature. As anode materials for LIBs, the resultant Co3O4 nanotubes show higher specific capacity and better cycle stability (856.4mAhg−1 at 0.25 C and 677.2mAhg−1 at 1 C up to 60 cycles), as well as enhanced rate capability as compared to Co3O4 nanowire counterparts (805.1mAhg−1 at 0.25C and 587.9mAhg−1 at 1 C). The performance enhancement mainly comes from the multiple advantages of nanotube configuration, such as higher surface areas, faster transportation path for ion/electron. It is expected that the as-prepared Co3O4 nanotubes are also promising active material for supercapacitors, chemical sensors and electrocatalysis.
A new type of asymmetric supercapacitor containing a MnFe2O4 negative electrode and a LiMn2O4 positive electrode in aqueous LiNO3 electrolyte has been synthesized and characterized. The nanocrystalline MnFe2O4 anode material has a specific capacitance of 99Fg−1 and the LiMn2O4 cathode a specific capacity of 130–100mAhg−1 under 10–100C rate. The cell has a maximum operating voltage window of ca. 1.3V, limited by irreversible reaction of MnFe2O4 toward reducing potential. The specific power and specific energy of the full-cell increase with increasing anode-to-cathode mass ratio (A/C) and saturate at A/C ∼4.0, which gives specific cell energies, based on total mass of the two electrodes, of 10 and 5.5Whkg−1 at 0.3 and 1.8kWkg−1, respectively. The cell shows good cycling stability and exhibits significantly slower self-discharge rate than either the MnFe2O4 symmetric cell or the other asymmetric cells having the same cathode but different anode materials, including activated carbon fiber and MnO2.
Cities contribute around 80% of global greenhouse gas emissions. There is currently a massive growth in urban areas internationally, especially in developing countries. Urban centers and cities should offer an effective answer to new problems arising from planning and expansion, according to criteria of sustainability. Decisions for sustainable cities planning and management should be taken on an evaluation of their consequences. Correspondingly, each strategy should be designed and undertaken with the right tools of study, analysis and prediction. This paper aims to offer an analysis of the aspects involved in designing sustainable cities. It involves an overview of published papers focusing on urban transport, building energy consumption, green areas planning, waste management and water supply on a city-wide scale. In order to give a broader concept of sustainability in cities, an analysis of other variables from a social point of view is also given. The discussion of this research reflects that the adoption of mechanisms to promote sustainable development is a matter not only of decision makers and designers, but also of users and citizens.
New class of hydrophobic ionic liquids based on bis(2,2,2-trifluoroethoxysulfonyl)imide ([(CF3CH2OSO2)2N]−, TFESI−) anion with various oniums, including N,N-dialkylimidazolium, tetraalkyl (ether-containing alkyl) ammonium, N-alkyl-N-methyl-pyrrolidinium, and -piperidinium, are prepared and characterized. Their physicochemical and electrochemical properties, including phase transitions, thermal stability, viscosity, density, ionic conductivity and electrochemical windows, have been determined. The influences of the structural variations in both the cation and anion on the above properties are extensively discussed. The key features of these new TFESI−-based ionic liquids are their low melting points (ranging from 9 to 44°C) and/or low glass transition (between −74 and −61°C), relatively low viscosities (44–426cP at 25°C), good thermal stability (T d >270°C), and wide electrochemical windows (ranging from 5.7 to 6.4V).
This work reports a room-temperature, solution-phase and one-pot method for macro-assembly of a three-dimensional (3D) reduced-graphene-oxide/copper hybrid hydrogel. The hydrogel is subsequently transformed into a highly conductive aerogel via freeze-drying. The aerogel, featuring reduced graphene oxide (rGO) networks decorated with Cu and CuxO nanoparticles (Cu/CuxO@rGO), exhibits a specific surface area of 48 m2/g and an apparent electrical conductivity of ∼33 and ∼430 S/m prior to and after mechanical compression, respectively. The compressed Cu/CuxO@rGO aerogel delivers a specific capacity of ∼453 mAh g−1 at a current density of 1 A/g and ∼184 mAh g−1 at 50 A/g in a 3 M KOH aqueous electrolyte evidenced by electrochemical measurements. Galvanostatic cycling tests at 5 A/g demonstrates that the Cu/CuxO@rGO aerogel retains 38% (∼129 mAh g−1) of the initial capacity (∼339 mAh g−1) after 500 cycles. The straightforward manufacturing process and the promising electrochemical performances make the Cu/CuxO@rGO aerogel an attractive electrode candidate in energy storage applications.
Introduction: Transcranial application of weak random noise may appear to be a promising tool for clinical neuroplasticity research, for it allows a painless, selective, focal, non-invasive and reversible excitability modulation of the cortex without an adaptation effect. The “random noise” signal contains all frequencies up to half of the sampling rate, i.e. a maximum of 640Hz. This random level of current is generated for every sample (sampling rate 1280 sps) and is normally distributed; the probability density function follows a bell-shaped curve. Methods: Stimulation was delivered by a battery-driven electrical stimulator (NeuroConn GmbH, Ilmenau, Germany) through conductive-rubber electrodes placed in two saline-soaked sponges. To detect these current-driven changes of excitability we used single-pulse TMS, frequently employed in these kind of studies. The intensity of the TMS pulse is calibrated before the experiment to induce a motor-evoked potential (MEP) amplitude of about 1mV in the resting first dorsal interosseous muscle. MEP size increases or decreases after an external stimulation of the brain reflecting excitability enhancement or reduction of the motor cortex. Following stimulation, 40 single test-pulse MEPs were recorded at a time constant of 4±0.04s eight times, i.e. approximately 0min, 5min, 10min post-stimulation and then every 10min up to 60min. Results: Applying 10-min random noise stimulation over the primary motor cortex induces excitability changes of up to 20–50%, as revealed by TMS, which lasts for 60min post-stimulation. However, RNS over the premotor cortex did not induce any significant excitability changes. The observed increase in MEP post- stimulation indicates that tRNS application has the ability to modulate levels of cortical excitability.
The effect of oxygen stoichiometry on the transition metal ordering and electrochemical activity of LiMn2−x Ni x O4 solid solutions was investigated. Temperature–oxygen-partial-pressure–composition (pO2–T–x) diagrams of ordered and disordered phases of LiMn2−x Ni x O4 (0.50≥ x ≥0.36) in the vicinity of order–disorder transition temperature (T c) was constructed by means of infrared spectroscopy, thermogravimetric analysis and galvanostatic measurements. Despite their simplicity and limitations over traditional diffraction techniques, all three techniques offered near excellent capability to distinguish ordered and disordered phases. The effect of oxygen-partial-pressure (pO2) in the annealing atmosphere and nickel content of the spinel on T c was studied. The transition temperature increased with pO2 and nickel content, except in oxygen-rich (pO2 =1) atmosphere for the maximum nickel content spinel of LiMn1.5Ni0.5O4. An explanation for the dependence of the transition temperature on the two variables and changes induced by the post-fabrication heat treatments is provided.
Due to cell-to-cell variations in battery pack, it is hard to model the behavior of the battery pack accurately; as a result, accurate State of Charge (SoC) estimation of battery pack remains very challenging and problematic. This paper tries to put effort on estimating the SoC of cells series lithium-ion battery pack for electric vehicles with adaptive data-driven based SoC estimator. First, a lumped parameter equivalent circuit model is developed. Second, to avoid the drawbacks of cell-to-cell variations in battery pack, a filtering approach for ensuring the performance of capacity/resistance conformity in battery pack has been proposed. The multi-cells “pack model” can be simplified by the unit model. Third, the adaptive extended Kalman filter algorithm has been used to achieve accurate SoC estimates for battery packs. Last, to analyze the robustness and the reliability of the proposed approach for cells and battery pack, the federal urban driving schedule and dynamic stress test have been conducted respectively. The results indicate that the proposed approach not only ensures higher voltage and SoC estimation accuracy for cells, but also achieves desirable prediction precision for battery pack, both the pack's voltage and SoC estimation error are less than 2%.
Well-defined mesoporous MnO2 nanosheet arrays have been directly grown on Ni foam current collectors using one-step electrodeposition, followed by a low-temperature thermal annealing process. The as-deposited MnO2 nanosheets are 20–25 nm thick on average and are mesoporous with a pore size ranging from 2 to 8 nm. The potential for using these MnO2 nanosheet arrays as supercapacitor electrodes has been explored by cyclic voltammetry and galvanostatic charge/discharge tests within a potential window of 0–1.0 V versus saturated calomel electrode. The cyclic voltammograms of the MnO2 nanosheet electrode show a typical pseudocapacitive behavior. The nanosheets exhibit specific capacitance of 201, 150, 122, 105 and 96 F g−1 at current densities of 1, 5, 10, 15 and 20 A g−1, respectively. Furthermore, it is found that upon cycling at 5 A g−1, the specific capacitance loses 35% of its initial value in the beginning 1800 cycles and then remains constant up to 3000 cycles, showing reasonably good cycling performance. The electrochemical impedance spectroscopy demonstrates that the equivalent series resistance and charge transfer resistance of the electrode are very low, suggesting that the nickel foam supported MnO2 nanosheet array is a promising binder-free electrode for use in pseudocapacitors.
Singapore is one of the most industrialised and urbanised economies in South-East Asia. Power supply is an important sub-system in its economy and heavily reliant on imported oil and natural gas. Due to its geographical area, clean/renewable energy sources for power generation are limited. At the same time, in its deregulated electricity market, the adoption of clean/renewable based power generation technology may be hindered by a market pricing mechanism that does not reflect externality costs. For a sustainable power supply, there is a need to change the conventional appraisal techniques. Life cycle assessment (LCA) and life cycle cost analysis (LCCA) are good tools to quantify environmental impacts and economic implications. LCA and LCCA are performed for centralised and distributed power generation technologies in Singapore, namely, oil and Orimulsion-fired steam turbines, natural gas-fired combined cycle plant, solar PV and fuel cell systems. A life cycle energy, emission and cost inventory is established. The results are discussed from the perspectives of fuel security, environmental protection and cost effectiveness of future power generation strategies for Singapore.
A polysiloxane-based gel electrolyte (PBGE) was prepared and used as a novel gel electrolyte in valve-regulated lead-acid (VRLA) batteries with tubular positive plates. Cyclic voltammetry (CV) and scanning electron microscopy (SEM) indicated that PBGE is more stable than fumed-silica gel electrolyte (FSGE). The properties of AGM (absorptive glass mat)-PBGE and PVC-FSGE tubular batteries were investigated by electrochemical techniques. The results showed that the AGM-PBGE tubular batteries have higher initial discharge capacity and better high-low temperature performance than PVC-FSGE. The improved electrochemical performance of the AGM-PBGE batteries may result from the high charge efficiency and the open three-dimensional network structure of PBGE. SEM and X-ray diffraction (XRD) spectroscopy showed that PBGE facilitates the conversion of the active-mass to lead dioxide, presenting a high formation efficiency. The addition of PBGE instead of FSGE not only simplifies the manufacturing process of tubular gel batteries, but also improves the utilization efficiency of positive active material (PAM), thus enhancing the battery performance and reducing the manufacturing cost.
An appropriate model is a prerequisite for accurate state-of-charge (SOC) estimation. The widely used equivalent circuit models (ECMs) employ a variety of forms; thus, to find the optimum ECM is a primary task for SOC estimation. In this work, we examined eleven ECMs to fulfill the following goals: (1) to compare the typical ECMs for accuracy, stability, and robustness of model and SOC estimation; (2) to compare and evaluate the robustness of the ECMs considering model and sensor errors. The results indicate that the model accuracy does not always improve by increasing the order of the RC network. Conversely, over-fitting problems appear with a certain probability. The first- and second-order RC models are the best choice owing to their balance of accuracy and reliability for LiNMC batteries. The higher-order RC model has better robustness considering the variation in model parameters and sensor errors. Independently of the ECM adopted, an accurate OCV-SOC curve and high precision sensors are essential.
Mesoporous LiFePO4 (LFP) microspheres embedded homogeneously with three-dimensional (3D) carbon nanotube (CNT) conductive networks were successfully prepared via an effective and controllable hydrothermal approach with the assistance of polyethylene glycol (PEG). Scanning electron microscopy (SEM) and N2 adsorption–desorption characterization demonstrated that porous structure of these microspheres could be well modulated by varying the molecular weight of PEG. The LFP/CNTs composite prepared using PEG400, which possessed the best mesoporous structure with the pore size centered at 40nm, and 3D CNT conductive network embedded in the microspheres homogeneously, exhibited the best electrochemical performance with high capacity retention of 95.7% even at 5C after 100 cycles. Essentially, in comparison with those samples without mesoporous structure or CNT networks, this hybrid microstructure could not only greatly enhance the electrical conductivity, but also facilitate the electrolyte penetration into the microspheres, thus markedly improving the electrochemical performance.
The present communication reports on the first electrodeposition of Ni(OH)2 on ZnO array supported on Ni foam. When applied as a binder-free electrode material for pseudocapacitive energy storage, the resulting ZnO@Ni(OH)2 array exhibits a high specific capacitance of 2028Fg−1 at a current density of 10Ag−1 with good cycling stability. Meanwhile, the array exhibits a superb rate capability. Even at an extremely high current density of 100Ag−1, the array still shows a very high specific capacitance of 1059Fg−1.
The effect of Ti-substitution on the electrochemical properties of LiNi0.5Mn1.5−x Ti x O4 was investigated by using half-cells paired with lithium metal, and full-cells paired with either graphite or Li4Ti5O12 (LTO) negative electrodes. In half-cells, Ti-substitution increased the operation voltage, but reduced the specific capacity. While some improvements in performance, such as higher operation voltage and less self-discharge, could be measured in the half-cells, the critical advantages of the Ti-substitution were readily observed in full-cell cycling. Compared with Ti-free LiNi0.5Mn1.5O4, the LiNi0.5Mn1.5−x Ti x O4 electrodes delivered improved full-cell performance whether paired with graphite or LTO negative electrodes; greater cycle life, higher cell operating voltage, and lower voltage polarization on charging/discharging. Based on relatively low self-discharge and high Coulombic efficiency, it is suggested that the Ti-substitution in LiNi0.5Mn1.5−x Ti x O4 retards electrolyte oxidation. In addition, scanning electron microscopy (SEM) images revealed that cycle-aged LiNi0.5Mn1.2Ti0.3O4 particle surfaces remained relatively clean compared with those of LiNi0.5Mn1.5O4 particles. These results are consistent with the hypothesis that Ti-substitution reduces electrolyte oxidation and retards or prevents some of the degradative parasitic reactions at the electrode/electrolyte interfaces during battery cell operation.
A novel and simple in-situ solid-state reaction route is developed to synthesize a three-dimensional (3D) porous carbon fiber film-supported Li3V2(PO4)3 membrane electrode. The carbon film is obtained via the carbonization of a bioproduct rice paper (RP). The carbon film can function as both a current collector and a 3D electronic conduction network for the loaded Li3V2(PO4)3 particles. The structure and electrochemical properties of the Li3V2(PO4)3 membrane electrode are characterized. As a free-standing membrane electrode, it exhibits good rate performance at room temperature with a specific capacity of 108 and 142mAhg−1 at 10C rate in the voltage range of 3.0–4.3V and 3.0–4.8V, respectively. It also shows good cycling performance with a specific capacity of 123mAhg−1 after 500 cycles at 1C rate in the voltage range of 3.0–4.8V.
A spinel LiMn2O4/C composite was synthesized by hydrothermally treating a precursor of manganese oxide/carbon (MO/C) composite in 0.1M LiOH solution at 180°C for 24h, where the precursor was prepared by reducing potassium permanganate with acetylene black (AB). The AB in the precursor serves as the reducing agent to synthesize the LiMn2O4 during the hydrothermal process; the excess of AB remains in the hydrothermal product, forming the LiMn2O4/C composite, where the remaining AB helps to improve the electronic conductivity of the composite. The contact between LiMn2O4 and C in our composite is better than that in the physically mixed LiMn2O4/C material. The electrochemical performance of the LiMn2O4/C composite was investigated; the material delivered a high capacity of 83mAhg−1 and remained 92% of its initial capacity after 200 cycles at a current density of 2Ag−1, indicating its excellent rate capability as well as good cyclic performance.
Background Comorbid developmental coordination disorder (DCD) in the patients with attention-deficit hyperactivity disorder (ADHD) often complicated the treatment strategy. Methylphenidate (MPH) improves the coordination problem in patients with ADHD. Aim The study intended to investigate the pathophysiology and the mechanisms of MPH in comorbid DCD of the adolescents with ADHD. Methods Brain images using technetium-99m ethyl cysteinate dimmer (99mTc-ECD) single photon emission computed tomography (SPECT) were done in 10 drug-naïve adolescents with ADHD without DCD and 5 adolescents with ADHD comorbid DCD. The baseline rCBF and changes of rCBF after 10 mg MPH challenge between two groups were compared using statistical parametric mapping (SPM99) analysis. Results Lower rCBF of bilateral frontal lobe, inferior parental lobe, and increased rCBF of right posterior cingulate gyrus, anterior lobe of cerebellum were found in ADHD comorbid DCD group compared to ADHD without DCD group. Decreased rCBF in the right occipital, inferior temporal lobe was found in ADHD comorbid DCD group after MPH while ADHD alone group revealed increased rCBF in bilateral occipital lobe. Conclusions The results help us understand the pathophysiology of DCD in ADHD adolescents. The different rCBF response to MPH provides a clue for future intervention of DCD in ADHD adolescents.
The objective of this study was to provide information on the liver of Salaria basilisca biomarkers variability due to spatial and seasonal factors. For this purpose, fishes were collected during the four seasons between November 2007 and August 2008 from polluted (S1) and unpolluted (S2) areas in the Gulf of Gabes. A set of biomarkers were measured in the hepatic tissue such us metallothioneins (MT) with their reduced and oxidized forms, labile zinc (Zn), 7-ethoxyresorufin-O-deethylase (EROD), DNA strand breaks (DNA) and lipid peroxidation (LPO). Results showed that captured specimens from S1 site, presented in summer and autumn a significant increase (p <0.0001) in the specific biomarkers of heavy metals contamination such as MT and labile Zn. It showed, also, in autumn a significant increase (p <0.0001) in tissue damage biomarkers such as LPO and DNA strand breaks. The utility of each biomarker is assessed in the context of the roles and advantages of selecting a battery of biomarkers and seasons for detecting contamination problems.
The aim of this study is to investigate changes in regional cerebral blood flow (rCBF) in awake people with untreated severe obstructive sleep apnoea (OSAs) compared with good sleepers (GSs).
The effect of partial substitution of Co for Ni on the structure and electrochemical properties of the thus formed La2Mg(Ni1− x Co x )9 (x = 0.1–0.5) quaternary alloys was investigated. All alloys are consisted of a main phase with hexagonal PuNi3-type structure and a few impurity phases (mainly La2Ni7 and LaNi). The increase of Co content in the alloys leads to an increase in both the cell volume and the hydride stability, and leads to a noticeable decrease in cell volume expansion rate (ΔV/V) on hydriding. The discharge capacity of the alloys at 50mA/g increases slightly with the increase of Co content and passes though a maximum of 404.5mAh/g at x = 0.2. As the Co content increases, the high-rate dischargeability of the alloy electrodes at 800mA/g (HRD800) decreases sharply from 72.8 (x = 0) to 24.5% (x = 0.5), yet the decrease of HRD800 of the alloy electrodes with lower Co substitution (with x ≤ 0.2) is much milder. The slower decrease of HRD800 (from 72.8 to 64.2%) of the alloys with x from 0 to 0.2 is mainly attributed to the decrease of eletrocatalytic activity for charge-transfer reaction, the more rapid decrease of the alloys with x > 0.2 is mainly attributed to the lowering of the hydrogen diffusion rate in the bulk of alloy. The cycling capacity retention rate (S 100) of the alloys increase greatly with increasing of Co content, increasing from 60.2% for the alloy with x = 0 to a much higher value of 87.9% for the alloy with x = 0.5. The improvement in cycling stability is attributed to the lower cell volume expansion on hydriding.