batterydata/paper-abstracts huggingface dataset:
Transition metal carbides as promising anode materials for lithium ion batteries (LIBs) have attracted wide attention due to their high conductivity and high capacity. In this work, we have developed MoC/C nanowires as anode materials with high capacity and excellent cyclic stability. These nanowires are featured by a mesoporous structure resulting from stacking of carbon coated MoC nanocrystals. This structure provides shortened paths for Li+ diffusion and freeways for electron transfer, moreover, it effectively relieves the volume change of MoC nanocrystallites during the discharge/charge cycles. Therefore, the MoC/C nanowires exhibit excellent cyclic stability even at high current densities. At 0.2 A g−1, they perform reversible capacity of 650.3 mAh g−1 after 350 cycles, with capacity retention of 93.4%. Even at a high current density of 2 A g−1, they maintain 455.4 mAh g−1 after 2000 cycles, with average capacity loss rate of only 0.004% per cycle. The high capacity and outstanding stability indicate the potential of the MoC/C nanowires as anode materials for high performance LIBs.
Volcanoes constitute an important source of aerosol. Here we report the size-resolved compositions of major water-soluble ions in particles collected in near-source emissions from three contrasting volcanoes (Solfatara, Vulcano and Stromboli, in Italy). Concentrations of soluble SO4 2−, Cl−, F−, NO3 −, H+, K+, Na+, NH4 +, Ca2+ and Mg2+ were determined in 11 particle size bins from 0.069 to >25.5μm in diameter. Soluble ions were most concentrated in the emissions from Solfatara and Stromboli. At Solfatara the major ions were NH4 + and Cl−, tightly correlated in ∼0.8–1.5μm diameter particles, strongly suggesting speciation as NH4Cl. At Stromboli enhanced levels of SO4 2−, H+, Na+, K+ and NH4 + were present in ∼0.5–1.5μm diameter particles. Near-source soluble sulphate was observed in the plumes from Stromboli and Vulcano, with that from Stromboli in much higher concentration (0.94–2.14 compared with 0.07–0.13μmolm−3). Comparing SO4 2− measurements from Vulcano to those from other volcanic systems suggests that near-source sulphate aerosol emissions scale with SO2 and contribute ∼0.03–0.05Tgyr−1 of sulphur to the atmosphere. Simple calculations suggest that all the particles containing these soluble ions will act as cloud condensation nuclei at typical atmospheric supersaturations.
A numerical prediction model is developed for the safety analysis of molten sodium–sulfur battery. Under the assumption that a crack occurred in a solid electrolyte of a cell, a rapid increase in the temperature and pressure from a direct reaction between sulfur and sodium can be predicted by solving equations for flow, energy and the chemical reaction. The crack, the powder-type in-filler and the carbon felt in the sulfur electrode are modeled by porous media approximations. The results are compared to experimental results with extreme value probability statistics for the data assessment. The effects of the size of the cell and wick tube, the depth of discharge, and the filler material are summarized quantitatively.
Rechargeable batteries and supercapacitors are widely investigated as the most important electrochemical energy storage devices nowadays due to the booming energy demand for electric vehicles and hand-held electronics. The large surface-area-to-volume ratio and internal surface areas endow two-dimensional (2D) materials with high mobility and high energy density; therefore, 2D materials are very promising candidates for Li ion batteries and supercapacitors with comprehensive investigations. In 2011, a new kind of 2D transition metal carbides, nitrides and carbonitrides, MXene, were successfully obtained from MAX phases. Since then about 20 different kinds of MXene have been prepared. Other precursors besides MAX phases and even other methods such as chemical vapor deposition (CVD) were also applied to prepare MXene, opening new doors for the preparation of new MXene. Their 2D nature and good electronic properties ensure the inherent advantages as electrode materials for electrochemical energy storage. In this review, we summarize the recent progress in the development of MXene with emphasis on the applications to electrochemical energy storage. Also, future perspective and challenges of MXene-based materials are briefly discussed regrading electrochemical energy storage.
Recent experiments have suggested that there is a critical size for patterned silicon (Si) thin film electrodes for delamination from a current collector during lithiation and delithiation cycling. However, no existing theories can explain this phenomenon, in spite of its potential importance in designing reliable electrodes for high-capacity lithium-ion batteries. In this study, we show that the observed delamination size effect can be rationalized by modeling thin film delamination in the presence of large scale interfacial sliding. A method is proposed to deduce the critical size for delamination based on the critical conditions for the nucleation and growth of edge or center cracks at the film-substrate interface under plane strain or axisymmetric conditions. Applications to lithiation of thin-film Si islands give results in excellent agreement with experimental observations.
Three different types of automotive lithium-ion pouch cells are analyzed with electrochemical impedance spectroscopy over a wide range of operating points in SOC (10–90%) and temperature (−10 to +40°C) with the goal of establishing parameters for an accurate linear equivalent circuit model. The impedance vs frequency is analyzed and attributed to physical behaviors from current collectors, electrode and electrolyte, charge transfer and diffusion. The change in resistance is statistically analyzed as a function of SOC and temperature in an effort to quantify if there are any monotonic patterns. Results show that the charge transfer resistance versus temperature represent the largest relative change of resistance, followed by diffusion resistance versus temperature and the electrolyte resistance over temperature. Only weak correlations with resistance versus SOC are found irregardless of frequency range. Frequency-domain fitted equivalent circuit model parameters are evaluated by comparison of physical measurements in long dynamic load cycles using root-mean-squared of the voltage error between model and physical measurements as performance index. A simple R+2RC model capturing diffusion dynamics performs best at RMSE 15.46mV, better than most similar studies and better than the more complex R +6RC also evaluated.
Carbon dynamics in vegetated ecosystems are influenced by plants, belowground bacteria, and their interactions. Consequently, quantifying the fate of new plant production, identifying bacterial carbon sources, and evaluating plant–microbe interactions can provide insight to carbon cycling and storage. To follow short-term carbon transformations in a Spartinaalterniflora—soil system, we applied 13C-labeled CO2 to aboveground leaves and chased it belowground into roots and bacterial lipids. Plant mesocosms were exposed to 13CO2 for 0, 1, 3, or 6 h. Incorporation of 13CO2 by plants and soil microbes was measured immediately after the incubation (Day 0) and 24 h later (Day 1). During a 24 h period, 41–64 % of the 13CO2 fixed by S. alterniflora was retained in leaves, 2.7–6.4 % was transferred to roots, and 30–55 % was lost via respiration. Small fractions of 13C assimilated by aboveground leaves were detected belowground in bacterial lipids on Day 1. Enrichment of lipids specific to sulfate reducing bacteria (10-methyl C16:0, cy-C17:0) indicated tight coupling between aboveground plant production and belowground anaerobic metabolisms. Overall, we found that a substantial fraction of new production was returned to the atmosphere within 24 h and that belowground bacteria were tightly coupled to plant dynamics.
The waste electrical and electronic equipment (WEEE or e-waste) are the globally recognized hazardous material, though containing a full spectrum of valuable and critical metals. India, being the fifth largest generator of WEEE, is facing a great challenge in the sustainable management of such waste. Therefore since the past few years, Government of India has been trying to establish a proper institutional and legislative framework to implement the sustainable management of WEEE in the country. Accordingly, the global issues related to WEEE and how it is being tackled by other countries/regions with implemented regulations has been reviewed in this paper. Furthermore, the status-quo of WEEE generation, management policies and recycling practices in India has been systematically assessed while emphasizing the key issues of future initiatives, environmental and health hazards. The mathematical model of WEEE generation in India along with identifying the influences of recycling in sustainable management of WEEE has also been established.
The MATRICS Consensus Cognitive Battery (MCCB) was administered to 293 schizophrenia outpatients and 210 community residents in Spain. Our first objective was to identify the age- and gender-corrected MCCB cognitive profile of patients with schizophrenia. The profile of schizophrenia patients showed deficits when compared to controls across the seven MCCB domains. Reasoning and Problem Solving and Social Cognition were the least impaired, while Visual Learning and Verbal Learning showed the greatest deficits. Our second objective was to study the effects on cognitive functioning of age and gender, in addition to diagnosis. Diagnosis was found to have the greatest effect on cognition (Cohen's d>0.8 for all MCCB domains); age and gender also had effects on cognitive functioning, although to a lesser degree (with age usually having slightly larger effects than gender). The effects of age were apparent in all domains (with better performance in younger subjects), except for Social Cognition. Gender had effects on Attention/Vigilance, Working Memory, Reasoning and Problem Solving (better performance in males), and Social Cognition (better performance in females). No interaction effects were found between diagnosis and age, or between diagnosis and gender. This lack of interactions suggests that age and gender effects are not different in patients and controls.
The effect of cobalt and manganese content on the dehydrogenation properties of air-exposed MmB5+x -type (Mm=mischmetal; B=Ni, Al, Co and Mn) alloys was investigated both in solid gas and electrochemical reactions. The cobalt and manganese content were varied separately while keeping constant the plateau pressure of the hydrides. The increase of the cobalt content leads to a decrease of the hydrogen capacity whereas the manganese content has no much effect. In solid gas reactions, the kinetics were found to be limited by the hydrogen diffusion through the surface oxidation layer. As for the electrochemistry, the kinetics are limited by a corrosion layer formed in alkaline medium. The desorption rates for both processes increase as the cobalt or manganese content decreases. This is thought to be due to an enhancement of the hydrogen diffusivity through the oxidation layer. As a result, a low cobalt or manganese content in MmB5+x alloys is found to be beneficial for the hydrogen desorption kinetics in both processes.
Unilateral spatial neglect is a disabling condition, frequently observed after right-hemisphere damage (RHD), and associated with poor functional recovery. Clinical and experimental evidence indicates that attentional impairments are prominent in neglect. Recent brain imaging and behavioral studies in neglect patients and healthy individuals have provided insights into the mechanisms of attention and have revealed interactions between putative attentional networks. We recruited 16 RHD patients and 16 neurologically intact observers to perform a lateralized version of the Attention Network Test devised by Posner and co-workers (Fan et al., 2002). The results showed evidence of interaction between attentional networks during conflict resolution. Phasic alertness improved the orienting deficit to left-sided targets, reducing the interference of distracters in the neglected visual field, thus facilitating conflict resolution in the majority of patients. Modulating alertness may be an important way of improving basic deficits associated with neglect, such as those affecting spatial orienting.
Cell-to-cell variations can drastically affect the performance and the reliability of battery packs. This study provides a model-based systematic analysis of the impact of intrinsic cell-to-cell variations induced by differences in initial state of charge, state of health, capacity ration, resistance and rate capability. The impact of these cell-to-cell variations was evaluated on the performance of battery packs of different topologies, from series to parallel, and chemistries. For each chemistry and topology, simulations were performed with different levels for each type of intrinsic variation as well as all variations together in order to investigate the combined effects. The most salient changes were observed for cells connected in series. The calculated incremental capacity response for the pack and the single cells was used to select different features of interest that changed depending on the type of variation. From this methodology, the automatic quantification of the variations was attempted at the pack and single cell level. Cell-to-cell variations make each battery pack unique; their quantitation is essential for accurate monitoring.
Practical open-loop capacity estimation models, such as the Arrhenius aging model, require parameter updating for the real-world capacity estimation in order to guarantee the estimation accuracy. In this paper, a novel capacity estimation method for lithium-ion batteries, based on the fusion estimation of charging curve sections and the discrete Arrhenius aging model using sequential extended Kalman filters, is proposed. The estimation method based on fractional charging curves is developed to estimate the battery capacity during vehicle charging, and the estimation results serve as the feedback using the first Kalman filter to update the model parameters of the discrete Arrhenius aging model. Then, the second Kalman filter makes a fusion capacity estimation based on the results of charging curve sections and the discrete Arrhenius aging model with the modified parameters. The results of the cycle life tests show that the proposed algorithm can modify the parameters of the discrete Arrhenius aging model online. And the fusion capacity estimation error is less than 1% when the model parameters reach a steady state.
A passive thermal management system (TMS) for LiFePO4 battery modules using phase change material (PCM) as the heat dissipation source to control battery temperature rise is developed. Expanded graphite matrix and graphite sheets are applied to compensate low thermal conductivity of PCM and improve temperature uniformity of the batteries. Constant current discharge and mixed charge–discharge duties were applied on battery modules with and without PCM on a battery thermal characteristics test platform. Experimental results show that PCM cooling significantly reduces the battery temperature rise during short-time intense use. It is also found that temperature uniformity across the module deteriorates with the increasing of both discharge time and current rates. The maximum temperature differences at the end of 1C and 2C-rate discharges are both less than 5 °C, indicating a good performance in battery thermal uniformity of the passive TMS. Experiments on warm-keeping performance show that the passive TMS can effectively keep the battery within its optimum operating temperature for a long time during cold weather uses. A three dimensional numerical model of the battery pack with the passive TMS was conducted using ANSYS Fluent. Temperature profiles with respect to discharging time reveal that simulation shows good agreement with experiment at 1C-discharge rate.
Single crystal Sb2S3 nanowires are synthesized successfully through a simple one-step hydrothermal method. The morphological and structural characterizations reveal the uniform nanowire morphology of single crystal Sb2S3 with orthorhombic structure. The Sb2S3 nanowires exhibit a relatively high reversible capacity of 579 mAh g−1 at a current density of 100 mA g−1 and good cycling stability with 80.5% capacity retention after 50 cycles. The good rate capability of the Sb2S3 nanowires is also demonstrated by discharge/charge tests. The comparative study of electrochemical performance is made for two kinds of electrodes with different conductive additive contents. Sb2S3 nanowires electrodes with 20% acetylene black deliver a higher reversible capacity of 742 mAh g−1 at a current rate of 50 mA g−1. The good electrochemical performance of single crystal Sb2S3 nanowires can be ascribed to the one dimensional nanostructure of Sb2S3.
Direct investigations of carbon exchange by grassland vegetation along elevation gradients from 620m a.s.l. to 1960m in the Alps were undertaken in the Berchtesgaden National Park, Germany and in Stubai Valley, Austria during 2002 and 2003, focusing on vegetation development in response to seasonal change in climate, where vegetation is not immediately influenced by grazing activity. The data were analyzed via model inversions with an empirical hyperbolic light response model and a physiological carboxylase-based process model. Differences were found in ‘high’ versus ‘low’ elevation sites in photosynthetic and respiratory capacity as well as their relationship to temperature environment and vegetation structure. Differentiation of the grassland types, which has a parallel in observations of grassland gas exchange worldwide as illustrated for the network projects CarboEurope and AmeriFlux, apparently depends on land use management, climate stress, nitrogen availability and plant community composition and dynamics. The importance of developing a better understanding of the observed differences or shifts in grassland ecosystem behavior in the context of assessing landscape, regional and continental scale water and carbon balances is discussed. The utility and need for simultaneous study of grasslands via eddy covariance and chamber methodologies, for parallel analysis of data with different models, and for supplementing field gas exchange observations with ancillary measurements of leaf structural and chemical composition in order to achieve new insight is emphasized.
Sulfur-graphene (S-GNS) composites have been synthesized by heating a mixture of graphene nanosheets and elemental sulfur. According to field emission electron microscopy, scanning electron microscopy with energy dispersive X-ray mapping, Raman spectroscopy, and thermogravimetric analysis, sulfur particles were uniformly coated onto the surface of the graphene nanosheets. The electrochemical results show that the sulfur-graphene nanosheet composite significantly improved the electrical conductivity, the capacity, and the cycle stability in a lithium cell compared with the bare sulfur electrode.
A key challenge for hydroxide exchange membrane fuel cells is the development of membranes with both high ionic conductivity and mechanical strength. Here the authors report a high-performance family of poly(aryl piperidinium) membranes enabling promising durability and power density.
Biotelemetry has become a key tool for studying marine animals in the last decade, and a wide range of electronic tags are now available for answering a range of research questions. However, comparatively, less attention has been given to attachment methods for these tags and the implications of tag retention on study design, especially when designing a comparative study looking at multiple species. Here, we reported our findings on acoustic tag retention rates for juveniles of two species of marine turtle: the green sea turtle (Chelonia mydas) and the hawksbill sea turtle (Eretmochelys imbricata). We captured both species twice annually (spring and fall) from 2012 through 2017, as part of a capture–mark–recapture study at Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands. We assessed tag retention rates using physical recaptures of turtles previously outfitted with an acoustic tag.
Battery packs of multi-batteries supply high voltage when batteries are connected in series and high capacity when connected in parallel, which provides a new substitution of power supply for portable electronic device. A simulation method is, therefore, proposed to simulate the discharge behaviors of battery system with parallel and/or series connection. Using the simulation proposed, voltage, discharging capacity and residual capacity of the pack and individual battery at every time unit may be calculated at a given discharge current. When one of the batteries in the series-connection has a distinctly lower capacity, this battery reaches its fully discharged state sooner than the others during discharge. The simulated current distribution of a battery pack of two different-capacity batteries in parallel shows that although the pack is discharged at constant current, current through each battery is neither a constant nor proportional to its capacity. A battery of higher capacity carries a larger current. A pronounced change in current is observed near the end of the discharge process where voltage is near the cut-off value. We believe the proposed simulation method may be extended to a battery pack of multiple batteries of any capacity in any number and connections.
Highly uniform lithium vanadium oxide nanoribbons were successfully prepared in large quantities using a facile hydrothermal approach without employing any surfactants or templates. The as-prepared products were up to hundreds of micrometers in length, about 200nm in width, and 20nm in thickness. These nanoribbons and nafion composite were employed to modify glassy carbon electrode, which displayed excellent electrochemical sensitivity and rapid response in detecting dopamine in phosphate buffer solution. Lithium ions can greatly increase the electron transfer between the electrode and biological materials, and significantly increase the reversibility of electrochemical process. A linear relationship between the concentrations of dopamine and its oxidation peak currents was obtained. The linear range for the detection of dopamine was 2.0×10−6 to 1.0×10−4 M with a detection limit of 1.0×10−7 M. In addition, the good reproducibility and long-term stability of the sensor make it valuable for further application.