batterydata/paper-abstracts huggingface dataset:
The fluorine gradient-doped LiNi0.5Mn1.5O4 spinels are synthesized by a facile one-step method and the effect of heat treatment on their structure, morphology, and electrochemical performance are investigated. The results show that introduction of fluorine leads to a larger lattice parameter and particle size, and the formation of F-enriched surface. Whereas at 400°C, the fluorine gradient-doped LiNi0.5Mn1.5O4 sample exhibits an improved long-term cycling stability and high rate performance, due to the suppression of the reaction between electrolyte and cathode, resulting in a decrease in the total resistance and the formation of a thin, uniform and smooth film on the surface. As a result of in situ XRD with charged pristine and the fluorine gradient-doped samples, the similar thermal-decomposition pathways from the charged spinel to the final NiMn2O4-type spinel structure with a small amount of NiMnO3 and α-Mn2O3 are observed. In addition, the disappearance temperature of the charged spinel structures is at about 280°C for the fluorine gradient-doped sample, exhibiting an improved thermal stability of high voltage cathode material. These results show that fluorine gradient-doped LiNi0.5Mn1.5O4 sample is a promising positive electrode material for high performance lithium ion batteries.
Traumatic spinal cord injury ( SCI) leads to serious neurological and functional deficits through a chain of pathophysiological events. At the molecular level, progressive damage is initially revealed by collapse of plasma membrane organization and integrity produced by breaches. Consequently, the loss of its role as a semi-permeable barrier that generally mediates the regulation and transport of ions and molecules eventually results in cell death. In previous studies, we have demonstrated the functional recovery of compromised plasma membranes can be induced by the application of the hydrophilic polymer polyethylene glycol (PEG) after both spinal and brain trauma in adult rats and guinea pigs. Additionally, efforts have been directed towards a nanoparticle-based PEG application.
A series of nanocomposite polymer electrolytes (NCPEs) comprising nanoparticles of BaTiO3, Al2O3 or SiO2 were prepared by electrospinning technique. The nano-sized ceramic fillers were incorporated into poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HEP)] membranes during the electrospinning process. The resultant porous membranes are good absorbent of the liquid electrolyte and exhibit high electrolyte retention capacity. The presence of the ceramic nanoparticles has positive effect on the mechanical properties of the membranes. The ionic conductivity and the electrochemical stability window of the electrospun P(VdF-HFP)-based polymer are enhanced by the presence of the fillers. The cell Li/LiFePO4 based on the NCPE containing BaTiO3 delivers a discharge capacity of 164mAh/g, which corresponds to 96.5% utilization of the active material. In comparison, the performance of Li/LiFePO4 cells with NCPEs containing Al2O3 and SiO2 was observed to be lower with respective discharge capacities of 153 and 156mAh/g. The enhanced performance of the BaTiO3-based-NCPE is attributed mainly to its better interaction with the host polymer and compatibility with lithium metal.
The effect of different ambient temperatures on the electrochemical properties of La4MgNi17.5Co1.5 hydrogen storage alloy was investigated. The X-ray diffraction pattern shows that the alloy consists of LaNi5-type phase and A5B19-type (Ce5Co19 + Pr5Co19) phase. With the increase of the ambient temperature, the maximum discharge capacity of the alloy electrodes increases from 353.33 (283 K) to 379.25 mAh/g (308 K), and the cyclic stability (S100) of the electrodes decreases from 80.19 (283 K) to 52.04% (308 K) due to the acceleration of pulverization, corrosion and oxidation at higher ambient temperature. Moreover, it is found that the increase of the temperature can accelerate the diffusion rate of hydrogen in the alloy (D) and increase the exchange current density (I0), which are beneficial for improving the activation performance and the high-rate dischargeability (HRD) of the alloy electrodes. The activation cycles of the electrodes decrease from 4 (283 K) to 1 (308 K), and the HRD900 of the electrodes sharply increases from 66.36 (283 K) to 95.64% (308 K).
Several studies suggest that highly emotional information could facilitate long-term memory encoding and consolidation processes via an amygdala-hippocampal network. Our aim was to assess emotional perception and episodic memory for emotionally arousing material in patients with temporal lobe epilepsy (TLE) who are candidates for surgical treatment. We did this by using an audiovisual paradigm. Forty-six patients with medically resistant TLE (26 with left TLE and 20 with right TLE) and 19 healthy controls were assessed with a standard narrative test of emotional memory. The experimental task consisted of sequential picture slides with an accompanying narrative depicting a story that has an emotional central section. Subjects were asked to rate their emotional arousal reaction to each stimulus after the story was shown, while emotional memory (EM) was assessed a week later with a multiple choice questionnaire and a visual recognition task. Our results showed that ratings for emotional stimuli for the patients with TLE were significantly higher than for neutral stimuli (p=0.000). It was also observed that patients with TLE recalled significantly less information from each slide compared with controls, with a trend to lower scores on the questionnaire task for the group with LTLE, as well as poorer performance on the visual recognition task for the group with RLTE. Emotional memory was preserved in patients with RTLE despite having generally poorer memory performance compared with controls, while it was found to be impaired in patients with LTLE.
Nowadays, the importance of electrical generation based on renewable energies is increasing, due to its low emissions of greenhouse gases. At the same time, Distributed Generation and Microgrids (MG) are becoming an important research line because of their peculiar characteristics. MGs are composed of small power sources which can be renewable, placed near customer sites. Moreover, they have the inherent property of islanding: the disconnection of either the MG from the main grid or a portion of a MG from the rest of the MG. There are two kinds of islanding: intentional or planned (for maintenance purposes), and unintentional or unplanned. The latter is mainly due to disturbances and it is used to avoid damages in sources and loads. It is the most critical case because it must be detected as soon as possible to activate all the control systems which allow continuing the energy production and distribution despite the disconnection. In islanding, it is crucial to ensure the power and the electrical signal quality. In grid-connected mode, the inverters use the electrical signal of the main grid as reference. Once in islanding, the main grid reference is lost and new control techniques for the inverters are needed in order to obtain the correct values of voltage magnitude and frequency in the MG. The main objective of this paper is to make a survey on MGs focussed on two important features: unplanned islanding and control of inverters in that scenario. The idea is to present the basic architectures and regulation techniques of MGs and to study the islanding behaviour, mainly the different detection techniques and the inverters’ control once islanded.
Vertically oriented arrays of high surface area TiO2 nanotubes (NTs) are fabricated by the fast and facile anodic oxidation of a titanium foil. The formation of well-defined one-dimensional nanotubular carpets is assessed by means of morphological Field Emission Scanning Electron Microscopy characterisation, while X-ray diffraction analysis and Transmission Electron Microscopy imaging confirm the amorphous nature of the samples. The electrochemical response evaluated in lab-scale lithium cells is highly satisfying with near-theoretical initial specific capacity and remarkable rate capability, noteworthy in the absence of binders and conductive agents, which would affect the overall energy density. A specific capacity exceeding 200 mAh g−1 is observed at very high 24C and approx. 80 mAh g−1 are retained even at very high 96C rate, thus accounting for the promising prospects in storage devices conceived for high power applications. Moreover, the NTs can perform with good cycling stability and capacity retention approaching 50% of the initial value after very long-term operation along with improved durability (> 2000 cycles).
Metal sulfides have gradually gained attention as preferable anode materials in sodium-ion batteries (SIBs) due to their high theoretical capacities. In this work, we report for the first time the synthesis of carbon coated ZnSnS3 nanocubes (ZnSnS3@C NCs) as high-performance anode material for SIBs. The outer carbon coating surrounding the ZnSnS3 active material not only enhances the electronic conductivity of the anode but also increases the electrode reaction active sites. Thus, it can greatly improve the reversible capacity as well as homogenize the repeated volume changes of the active material and decrease the mechanical stress caused during the prolonged charge/discharge process, which could finally enable an enhanced electrode stability. Electrochemical test results demonstrated that the introduced ZnSnS3@C NC anode is capable of delivering a high reversible capacity of 661.4 mAh g−1 at a current density of 100 mA g−1 after 250 cycles (with capacity retention of 97.1%) and demonstrating a stable Coulombic efficiency of over 99%. To the best of our knowledge, both the reversible capacity and cycling stability performance introduced in this work are so far the best among metallic sulfur-based anodes and are even superior to some recently reported SnS2-based anodes.
Lithium-ion batteries have demonstrated excellent energy density, reliability, and life in commercial applications. Several new Navy and undersea applications are emerging that need the high energy density and high power capabilities that the lithium-ion technology offers. Such applications have historically utilized silver–zinc technology for their power source. However, life cycle costs, maintenance and logistics issues, and wet-life limitations are true detriments in these applications. Lithium-ion technology has demonstrated the energy and power density of silver–zinc, but with much improved cycle life, shelf life, and low maintenance properties. For these reasons, and others, many under water applications are looking to lithium-ion to provide the performance of the silver–zinc system, but at a greatly reduced life-cycle cost.
The well-crystallized LiFePO4 cathode material was synthesized by liquid deposition method using mesoporous Ketjen Black (KB) as template. The LiFePO4/KB nanocomposite was characterized by X-ray diffraction (XRD), TG, SEM, HR-TEM, nitrogen sorption, galvanostatic charge/discharge test and EIS. The results indicate that the LiFePO4 particles about 10nm were embedded in the mesoporous of Ketjen Black. The composite has an uniform particle size and 3D network structure, which delivers a discharge capacity of 120.2mAh/g, 100.1mAh/g, 85.5mAh/g and 64.5mAh/g at 1C, 5C, 10C and 20C under −20°C respectively. Moreover, the composite also exhibit relatively high cycling performance and the capacity maintains 93.6% at 5C and 91.2% at 10C under −20°C after 200 cycles. The stable high rate performance possibly fulfills the requirements of rechargeable lithium batteries for high power applications especially at low temperature.
We report a facile strategy to synthesize polyaniline/molybdenum disulfide (PANI/MoS2) nanocomposite by in situ polymerization to achieve excellent electrochemical properties for application as supercapacitor electrodes. MoS2 nanocomposite with graphene-like subunits structure is prepared by a hydrothermal method and serves as an excellent 2D conductive skeleton that supports a highly electrolytic accessible surface area of redox-active PANI and provides a direct path for electrons. The layered nanostructure of PANI/MoS2 composites provides a larger contact surface area for the intercalation/deintercalation of protons into/out of active materials and shortens the path length for electrolyte ion transport. The structure of the composite is characterized by scanning electron microscope, transmission electron microscope, X-ray powder diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis, and the electrochemical performances of the composites are evaluated by cyclic voltammogram and galvanostatic charge–discharge. The maximum specific capacitance of 575Fg−1 at 1Ag−1 is observed at the PANI/MoS2 electrodes. The energy density of 265Whkg−1 is obtained at a power density of 18.0kWkg−1. In addition, the PANI/MoS2 composite electrode shows excellent long-term cyclic stability (less than 2% decrease in specific capacitance after 500 cycles at a current density of 1Ag−1), indicating a positive synergistic effect of MoS2 and PANI for the improvement of electrochemical performance.
Background Increasing evidence indicates impairments of empathic abilities in schizophrenia that may impact outcome and course of the disease. While there is consensus on the presence of deficits in ‘theory of mind’ in this disorder, i.e. cognitive aspects of mental state attribution, the ability to infer emotional experiences of others, i.e. affective empathy, has not been investigated so far. Methods We assessed multiple dimensions of empathy in 45 schizophrenic patients and 45 healthy controls, matched for age and gender, with a self-rating instrument, the Interpersonal Reactivity Index (IRI). To control for modulating effects of cognitive deficits, a neuropsychological test battery was employed. Results Schizophrenic patients showed significantly lower scores in cognitive empathy (‘perspective taking’: F =12.176, df =1, p =0.001) but more self-related aversive feelings in response to the distress of others (‘personal distress: F =16.477, df =1, p <0.001). Self-ratings of affective empathy, i.e. concern for others, did not differ between groups. Results in the domains of empathy were not explained by symptoms or neurocognition as revealed by regression analysis. However, lower scores in ‘perspective taking’ were found with advancing duration of illness (r =−0.453, p =0.002). Conclusions Results indicate reductions of cognitive empathy but relatively preserved emotional empathic abilities in schizophrenia. Although previous studies observed deficits in emotion perception and expression, our findings support the concept of differentially disturbed abilities in cognitive and emotional empathy in schizophrenia.
The aim of the present study was to investigate the effect of low-normal and high-normal levels of IGF-1 in growth hormone (GH) deficient adults on cognition and wellbeing during GH treatment.
Cross-linked trimethylolpropane trimethylacrylate-based gel polymer electrolytes (GPE) were prepared by in situ thermal polymerization. The ionic conductivity of the GPEs are >10−3 Scm−1 at 25°C, and continuously increased with the increase of liquid electrolyte content. The GPEs have excellent electrochemical stability up to 5.0V versus Li/Li+. The LiCoO2|TMPTMA-based GPE|graphite cells exhibit an initial discharge capacity of 129mAhg−1 at the 0.2C, and good cycling stability with around 83% capacity retention after 100 cycles. Both the simple fabricating process of polymer cell and outstanding electrochemical performance of such new GPE make it potentially one of the most promising electrolyte materials for next generation lithium ion batteries.
The kinetics of the electrochemical lithium insertion reaction in nanosized V2O5 prepared from a fluorination synthesis in solution is investigated by AC impedance spectroscopy. The experimental data are obtained vs. x in nano-LixV2O5 over the wide composition range 0≤x<1.8 and vs. temperature. Kinetic parameters for Li electroinsertion in nanosized V2O5 are achieved here for the first time. The charge transfer kinetics is little affected by Li content. A moderate evolution of the chemical diffusion coefficient is related to the peculiar single-phase behavior induced by the nanosize effect combined with shorter Li diffusion pathways. Comparison with experimental data obtained for microsized analogue vs. temperature reveals a much lower activation energy barrier (0.06 eV) for the lithium diffusion process in nanosized V2O5 that explains the significant improvement in electrochemical performances and especially a better rate capability. This work illustrates how nanosizing promotes the kinetics of Li insertion reaction, in agreement with the new and specific structural response of nanosized vanadium pentoxide.
The effects of combined driving and vehicle-to-grid (V2G) usage on the lifetime performance of relevant commercial Li-ion cells were studied. We derived a nominal realistic driving schedule based on aggregating driving survey data and the Urban Dynamometer Driving Schedule, and used a vehicle physics model to create a daily battery duty cycle. Different degrees of continuous discharge were imposed on the cells to mimic afternoon V2G use to displace grid electricity. The loss of battery capacity was quantified as a function of driving days as well as a function of integrated capacity and energy processed by the cells. The cells tested showed promising capacity fade performance: more than 95% of the original cell capacity remains after thousands of driving days worth of use. Statistical analyses indicate that rapid vehicle motive cycling degraded the cells more than slower, V2G galvanostatic cycling. These data are intended to inform an economic model.
The decrease in the resistance at solid electrolyte and electrode interfaces has become a critical issue in the development of solid-state lithium batteries. To understand the ionic transport properties across solid electrolyte and electrode interfaces, thin-film batteries consisting of flat epitaxial films are of considerable importance. Herein, we report the operation of bottom-current-collector-free thin-film batteries using LiNi0.8Co0.2O2 epitaxial thin films. As the bottom current collector is not inserted between the substrates and LiNi0.8Co0.2O2, the surface of LiNi0.8Co0.2O2 is very flat, with a surface roughness average of approximately 0.44 nm. This study proposes a very flat electrode surface suitable for the investigation of interfacial phenomena at solid electrolyte and electrode interfaces.
We tested sensitivity to coherent motion (CM) in random dot kinematograms in a group of 5-year-old preschool children genetically at risk for dyslexia, compared to a group of well-matched control children. No significant differences were observed, either in a group analysis or in an individual deviance analysis. Nonetheless, CM-thresholds were significantly related to emerging orthographic skills. In a previous study on the same subjects (Boets, Wouters, van Wieringen, & Ghesquière, in press), we demonstrated that both risk groups already differed on measures of phonological awareness and letter knowledge. Moreover, auditory spectral processing (especially 2Hz FM detection) was significantly related to phonological ability. In sum, the actual visual and previous auditory data combined, seem to suggest an exclusive relation between CM sensitivity and orthographic skills on the one hand, and FM sensitivity and phonological skills on the other.
Three-dimensional (3D) hierarchical heterostructures have been widely studied for energy storage because of their amazing synergistic effect. However, a detailed characterization how the branched structure affects the backbone structure during electrochemical cycling, and the specific relationship between the backbone and the branched heterogeneous structure (namely synergistic effect) have been rarely revealed. In addition, the controllable synthesis of this system still remains a great challenge. Herein, we developed a one-step gradient hydrothermal method to obtain a series of 3D hierarchical heterogeneous nanostructures, including V2O5/NaV6O15, V2O5/ZnV2O6 and V2O5/CoV2O6, through controlling the sequence of nucleation and growth processes of different structural units in the same precursor. On the basis of time-resolved in situ X-ray diffraction (XRD) characterizations, we clearly elucidated the synergistic effect between the branched and backbone structure. During the synergistic effect, the branched NaV6O15 helps to reduce the potential barrier during lithium-ion insertion/extraction, buffers the impact of crystal-system transformations during the charge/discharge process; the backbone V2O5 is beneficial to increase the charge/discharge capacity, inhibits the self-aggregation of branched NaV6O15 and maintains the stability of 3D structure. Consequently, 3D V2O5/NaV6O15 hierarchical heterogeneous microspheres exhibit the best electrochemical performance than pure V2O5 and V2O5/NaV6O15 physical mixture in lithium-ion batteries (LIBs). When tested at a high rate of 5Ag−1, 92% of the initial capacity can be maintained after 1000 cycles. We believe this method will be in favor of the construction of 3D hierarchical heterostructures and this specific synergistic effect investigated by in situ XRD will be significant for the design of better electrodes.
The electrochemical behaviour of nickel and its oxides in molten carbonates is very complex because of the continuous growth of the NiO layer and the material losses during the oxidation and reduction processes. Thus, cyclic voltammograms have been realised in molten Li2CO3+Na2CO3 at 650°C at different electrodes (gold covered by NiO, fresh and aged nickel); they allowed us to identify, at different scan rates, the reactions associated with the peaks observed. In particular, thanks to a planar nickel disc electrode, with a well-defined surface, the principal reduction peak has been attributed to the transformation of NiO into Ni. Other reduction peaks, occurring at lower potentials, are probably due to the same reaction and their presence to phase transitions. Evidence was given for the existence of a Ni/Ni2+ system and the formation of Ni(III), most probably NaNiO2, by the oxidation of NiO at relatively high potentials.
An effective method to estimate the integrated state of charge (SOC) value for the lithium-ion battery (LIB) pack is proposed, because of its capacity state estimation needs in the high-power energy supply applications, which is calculated by using the improved extended Kalman filter (EKF) method together with the one order equivalent circuit model (ECM) to evaluate its remaining available power state. It is realized by the comprehensive estimation together with the discharging and charging maintenance (DCM) process, implying an accurate remaining power estimation with low computational calculation demand. The battery maintenance and test system (BMTS) equipment for the aerial LIB pack is developed, which is based on the proposed SOC estimation method. Experimental results show that, it can estimate SOC value of the LIB pack effectively. The BMTS equipment has the advantages of high detection accuracy and stability and can guarantee its power-supply reliability. The SOC estimation method is realized on it, the results of which are compared with the conventional SOC estimation method. The estimation has been done with an accuracy rate of 95% and has an absolute root mean square error (RMSE) of 1.33% and an absolute maximum error of 4.95%. This novel method can provide reliable technical support for the LIB power supply application, which plays a core role in promoting its power supply applications.