batterydata/paper-abstracts huggingface dataset:
Fluorinated graphene hydrogels (FGHs) are synthesized through a one-step hydrothermal process and applied as the binder/additive-free electrode materials for supercapacitors. Along with the reduction of graphene oxide (GO), fluorine atoms incorporate into the graphene framework through the substitution process with the residual phenol, ether or carbonyl groups, forming different fluorine species subsequently. The fluorine content and the CF bond configuration are easily adjusted by the hydrothermal temperature. X-ray photo electron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectra indicate the mainly existent of semi-ionic CF bonds in the prepared FGHs. The semi-ionic CF bonds in FGHs facilitate the ion transport, enhance the electrical conductivity and provide active sites for the faradic reaction. Therefore, the electrochemical performances of FGHs are better than the fluorine-free graphene hydrogel prepared by the same hydrothermal process. FGH prepared at the hydrothermal temperature of 150 °C exhibit the highest specific capacitance (227 F g−1) and the best rate capability. The corresponding symmetric supercapacitor delivers the power density as high as 50.05 kW kg−1 at the current density of 50 A g−1. These results indicate the FGHs are the ideal electrode materials with the great potential in the field of high-power supercapacitors.
During battery discharge, the heat generated is the sum of the Joule (resistive) and enthalpic (chemical) heating effects. Conversely, during battery charging, the heat generated is the Joule minus the enthalpic heating. If the conditions are carefully selected, one can observe a net battery cooling during charging. However, an interesting phenomenon takes place during overcharge. Those cells designed as sealed recombinant systems develop significant heating. Flooded designs do not exhibit this effect. The applied electric power generates energetic reaction products as a consequence of the electrochemical reactions. This is an energy absorbing process. The gasses are then vented into the environment. Since the sealed cells undergo a closed recombination cycle, i.e., no material is exchanged with the environment, the rate of heat generated is proportional to the power input to the cell. Essentially, the cell is behaving in the manner of a resistor. In this connection, the thermal runaway phenomenon that has been often observed in starved electrolyte cell designs raises a potential problem in battery applications. It is not efficient to design around the worst case scenario, i.e., anticipating the thermal runaway effect. It is wiser to detect its onset and shut down the charging process. An alternative approach is to develop an understanding of the thermal runaway process and, perhaps, develop a method for eliminating or effectively controlling it. A study was performed in an attempt to model the thermal runaway effect. In short, the effect appears to be related to the electrolyte distribution in the separator. This suggests that modification of the AGM separator properties could provide a means for better controlling the thermal runaway failure mode.
This study was an effort to extend the evaluation of orientation technology for promoting independent indoor traveling in persons with multiple disabilities. Two participants (adults) were included, who were to travel to activity destinations within occupational settings. The orientation system involved (a) cueing sources only at the destinations (i.e., a single sound source per destination), (b) a newly developed electronic control device that allowed the participants to easily manage the activation of the sources at the destinations, and (c) the provision of approval or encouragement messages. Both participants were successful in using the system and performed their travels to the destinations fairly correctly and in relatively short amounts of time within (a) the occupational setting used for the intervention and (b) a similar occupational setting used for checking generalization effects. The findings are discussed in relation to the importance of independent indoor traveling and the impact of the new technology.
It is shown that, in a sustainable energy future, energy for the electricity grid will probably be derived largely from the renewable sources of wind and solar radiation. Because both are intermittent, any infinite busbar grid supplying a metropolitan area must necessarily be buffered from these intermittencies by massive energy storage on the gigawatt-day level. It is then demonstrated that, under presently foreseeable scientific capabilities, only underground pumped hydro and advanced adiabatic compressed air energy storage appear capable of meeting anticipated technological and economic constraints. Neither has ever been constructed and tested; but even so it is predicted that underground pumped hydro ultimately will prove to be superior.
Previous studies have noted the importance of electricity storage and hydrogen technologies for enabling large-scale variable renewable energy (VRE) deployment in long-term climate change mitigation scenarios. However, global studies, which typically use integrated assessment models, assume a fixed cost trajectory for storage and hydrogen technologies; thereby ignoring the sensitivity of VRE deployment and/or mitigation costs to uncertainties in future storage and hydrogen technology costs. Yet there is vast uncertainty in the future costs of these technologies, as reflected in the range of projected costs in the literature. This study uses the integrated assessment model, MESSAGE, to explore the implications of future storage and hydrogen technology costs for low-carbon energy transitions across the reported range of projected technology costs. Techno-economic representations of electricity storage and hydrogen technologies, including utility-scale batteries, pumped hydro storage (PHS), compressed air energy storage (CAES), and hydrogen electrolysis, are introduced to MESSAGE and scenarios are used to assess the sensitivity of long-term VRE deployment and mitigation costs across the range of projected technology costs. The results demonstrate that large-scale deployment of electricity storage technologies only occurs when techno-economic assumptions are optimistic. Although pessimistic storage and hydrogen costs reduce the deployment of these technologies, large VRE shares are supported in carbon-constrained futures by the deployment of other low-carbon flexible technologies, such as hydrogen combustion turbines and concentrating solar power with thermal storage. However, the cost of the required energy transition is larger. In the absence of carbon policy, pessimistic hydrogen and storage costs significantly decrease VRE deployment while increasing coal-based electricity generation. Thus, R&D investments that lower the costs of storage and hydrogen technologies are important for reducing emissions in the absence of climate policy and for reducing mitigation costs in the presence of climate policy.
High-energy rechargeable lithium metal batteries have attracted soaring attention because of high specific capacity and low electrochemical potential of lithium metal. Unfortunately, the lithium dendrite growth upon Li plating severely hinders its practical application. Herein, we report the preparation of ionic liquid (IL) immobilized polymer gel electrolytes with strong ion-dipole interactions between imidazolium-based IL and fluorinated copolymer gel for stable and dendrite-free Li+ plating/stripping. The adoption of IL leads to the formation of a tightly cross-linked gel framework with tethered anions, providing greatly-improved mechanical strength, good heat resistance, favorable self-healing capability, high ionic conductivity, and a stable electrochemical window up to 4.5 V vs. Li+/Li that can satisfy the demand of high-voltage cathodes. The membrane of IL-immobilized polymer gel electrolyte enabled dendrite-free Li deposition, showing stable cycling durability for 1000 h at 0.5 mA cm−2, and the functional mechanism was carefully investigated. By coupling with this gel electrolyte membrane, the LiFePO4/Li cell exhibit much superior cycling stability and rate performance. Moreover, the lithium-sulfur batteries assembled with the IL-immobilized polymer gel electrolyte also show efficient suppression of polysulfide shuttling and self-discharge, bringing high specific capacity and long cycling life.
Degradation due to capacity fade is a major cause of concern involved in the design and implementation of lithium-ion battery. In particular, the formation and growth of Solid Electrolyte Interface (SEI) have been considered as one of the primary degradation mechanisms affecting the cycle life of the battery. Over the past decade, several models have been reported towards simulation of SEI growth-induced degradation and prediction of cycle life. In this work, an efficient reduced-order electrochemical model was developed for a lithium cobalt oxide/graphite battery. A reaction–diffusion based SEI model was integrated with the electrochemical model to predict the cyclic capacity loss due to electrolyte deposition on the anode. The algorithm developed for this battery module was designed to reduce the computational time for capacity fade calculation with any (dis)charging protocol. The model was also applied for a lithium ferrous phosphate/graphite cell and in both cases, the fade predictions were within ±1% deviation from the experimental results. A comparison of two charging protocols was undertaken to identify approaches that improve capacity fade characteristics of battery. The electrochemical benefit of a reduced fading rate for aged (or used) lithium battery was investigated. A concept of “aged-battery” was proposed to be used as an advantage for better cycle-life in battery for biomedical devices and recycling of electric vehicle battery for solar panels applications. An economic analysis was performed to justify the benefits from lower fade that was weighed against the additional cost involved in aging the battery.
Si/Ni3Si-encapulated carbon nanofiber composites are synthesized by a facile one-pot electrospinning method and employed as three-dimensional network structured anode materials for lithium ion batteries. It is demonstrated that the composite exhibited increased cycling performance with a reversible capacity of 1132.4mAhg−1 after 200 cycles, which is 45% higher compared to the bare Si. The improved battery performance is attributed to the alloying of Si with Ni, which could effectively alleviate the volume expansion during lithium insertion/extraction. In addition, the formation of one dimensional nanofiber in which Si/Ni3Si nanoparticles are well distributed not only increases the electronic conductivity, but also enhances the mechanical strength of the electrodes, resulting in increased cycle stability.
Understanding the reactivity of lithium toward new materials proposed for electrodes in lithium ion batteries is an important step to improve material performances. In this work, the reactivity with Li of a new negative electrode material with atomic composition Ni0.14Sn0.17Si0.32Al0.037C0.346 is carried out. Powerful characterization methods (Operando XRD, Transmission Mössbauer Spectroscopy TMS and Cyclic Voltammetry CV) have been used to investigate electrochemical and structural transformations along cycling. The excellent behavior of this new composite is achieved thanks to the reversible reactions of all components with lithium, namely Si, Ni3,4Sn4 and C phases. Formation of Li–Sn and Li–Si alloys is identified and discussed.
Asymmetric supercapacitors (ASCs) as a promising candidate to complement batteries, have been studied for decades due to the relatively high power density. The energy storage of ASCs is significantly affected by the well-designed electrode material and delicate charge balance of electrodes. With the hope to design better supercapacitor devices, we firstly synthesize C-NiO/NiCo2O4 nanocomposites with the modified nanowire structure and a small amount of carbon, effectively boosting the specific capacitance and cyclic-stability. In addition, a multi-electrode system is developed to investigate match degrees of C-NiO/NiCo2O4//AC ACSs, and the inter-restricted behavior of positive and negative electrodes. By this real-time electrochemical method, the potential contributions of electrodes in ASCs are further revealed during charge/discharge process. Therefore, ASC device with optimal match degree delivers areal capacitance up to 3482 mF cm−2, and the maximum energy and power density of 42.69 mWh cm−3 and 1.66 W cm−3. Importantly, this work throws light on the fundamental study for supercapacitors in terms of materials design and charge match degrees.
Low energy density is the key issue that needs to be addressed for sodium ion batteries. Antimony sulfide (Sb2S3) with high theoretical capacity is considered as an ideal anode, but it suffers from poor electrochemical activity and consequently, low energy density. Simple hollow Sb2S3 structures with high electrochemical activity offer high gravimetric energy density, while large internal voids significantly decrease the volumetric energy density. Here, multi-shell Sb2S3 was synthesized as an anode for sodium ion batteries, exhibiting much higher reversible capacity and gravimetric energy density than the pristine Sb2S3. Moreover, the multi-shell structure presents higher volumetric energy density with enhanced durability than its single-shell counterpart due to the optimized utilization of the inner void. Operando synchrotron-based X-ray powder diffraction (XRPD) was used to verify the enhanced electrochemical activity originated from more complete conversion electrochemical reactions. The multi-shell Sb2S3 design may provide a guide for the development of high-performance hollow structured anodes with preserved high energy density.
The effects of thermal annealing on the performance of hydrogenated silicon nitride anode (prepared by plasma enhanced chemical vapor deposition, PECVD) are investigated by varying annealing temperatures. The relationship between the annealing temperatures, microstructures and electrochemical behaviors of the anodes is revealed. The capacity of the anodes with low-temperature annealing (≤400°C) is quite low firstly but increases abruptly after several charge/discharge activation processes. Due to weak strength of hydrogen-containing bonds in the PECVD silicon nitride, dehydrogenation occurs with cycling, which is effective to activate the anodes and thus result in the abrupt increase in the anode capacity. With increasing the annealing temperature to 450°C, the thermal treatment can break the hydrogen-containing bonds (induce dehydrogenation) and activate the anodes; therefore, the anodes with relatively high-temperature annealing (≥450°C) exhibit a high capacity even with no electrochemical activation processes needed. The mechanical properties of the anodes also depend on the thermal treatment and the anode elastic modulus and hardness increase with increasing the annealing temperature, which results in a poor mechanical stability and thus poor cycling performance of the anode with high-temperature annealing (~600°C). Compared with the anode with lower- or higher-temperature annealing, the anode with an appropriate annealing (~450°C) shows higher and more stable reversible capacity (~1001mAhg−1 at 0.6C over 200cycles) and better rate performance (~327mAhg−1 at 6.0Ag−1).
We report a novel composite of sulfur loaded in micropore-rich carbon aerogel (CA-S), as cathode of lithium-sulfur battery. Carbon aerogel (CA) is synthesized through phenol-formaldehyde reaction with a low catalyst concentration and carbonization under high temperature, and loaded with sulfur via chemical deposition and heat treatment. The physical properties of the resulting CA and the electrochemical performances of the resulting CA-S are investigated by scanning electron microscopy, thermal gravimetric analysis, Brunauer-Emmett-Teller characterization, electrochemical impedance spectroscopy, and galvanostatic discharge/charge test, with a comparison of a common carbon material, acetylene black (AB), and sulfur loaded in AB (AB-S). It is found that the CA is micropore-rich with micropore volume over 66% of total pore volume, and the CA-S exhibits significantly improved cyclic stability compared with AB-S. The improved performance of CA-S is attributed to the confinement of the micropores in CA to small sulfur allotropes and corresponding lithium sulfides.
Aging of brain structure and function is a complex process characterized by high inter- and intra-individual variability. Such variability may arise from the interaction of multiple factors, including exposure to stressful experience and mood variation, across the lifespan. Using a multimodal neuroimaging and neurocognitive approach, we investigated the association of stress, mood and their interaction, in the structure and function of the default mode network (DMN), both during rest and task-induced deactivation, throughout the adult lifespan. Data confirmed a decreased functional connectivity (FC) and task-induced deactivation of the DMN during the aging process and in subjects with lower mood; on the contrary, an increased FC was observed in subjects with higher perceived stress. Surprisingly, the association of aging with DMN was altered by stress and mood in specific regions. An increased difficulty to deactivate the DMN was noted in older participants with lower mood, contrasting with an increased deactivation in individuals presenting high stress, independently of their mood levels, with aging. Interestingly, this constant interaction across aging was globally most significant in the combination of high stress levels with a more depressed mood state, both during resting state and task-induced deactivations. The present results contribute to characterize the spectrum of FC and deactivation patterns of the DMN, highlighting the crucial association of stress and mood levels, during the adult aging process. These combinatorial approaches may help to understand the heterogeneity of the aging process in brain structure and function and several states that may lead to neuropsychiatric disorders.
We propose an intelligent decision support system based on sensor and computer networks that incorporates various component techniques for sensor deployment, data routing, distributed computing, and information fusion. The integrated system is deployed in a distributed environment composed of both wireless sensor networks for data collection and wired computer networks for data processing in support of homeland security defense. We present the system framework and formulate the analytical problems and develop approximate or exact solutions for the subtasks: (i) sensor deployment strategy based on a two-dimensional genetic algorithm to achieve maximum coverage with cost constraints; (ii) data routing scheme to achieve maximum signal strength with minimum path loss, high energy efficiency, and effective fault tolerance; (iii) network mapping method to assign computing modules to network nodes for high-performance distributed data processing; and (iv) binary decision fusion rule that derive threshold bounds to improve system hit rate and false alarm rate. These component solutions are implemented and evaluated through either experiments or simulations in various application scenarios. The extensive results demonstrate that these component solutions imbue the integrated system with the desirable and useful quality of intelligence in decision making.
Nanostructured, aluminum-stabilized nickel, hydroxides described as Ni1−x Al x (OH)2.(CO3) x/2·nH2O (x=0.05–0.2), which are similar to α-Ni(OH)2·xH2O in crystal structure are examined as cathode materials for Ni–Cd cells. The structure, morphology and electrochemical performance are investigated. The structural changes and stability of nanophase aluminum-stabilized, alpha nickel hydroxides with different x values analyzed during cycling by means of powder X-ray diffraction. Compared with β-Ni(OH)2, the nanophase, aluminum-stabilized α-Ni(OH)2 with x=0.15 is highly stable against overcharge.
The formation process presently used in the manufacture of lithium-ion batteries includes the solid electrolyte interface (SEI) growth process and another process for lithium intercalation into carbon. The latter process is both time and energy consuming. This study proposes a new concepts that can shorten the formation time by narrowing the potential range and bypassing the intercalation step during formation. The optimum cut-off voltage is 3.7V for industrial LiCoO2|C cells, and the formation time is reduced to less than one half of that required in the conventional formation procedure. Cycle performance is not affected significantly because the desired SEI growth is mainly completed in the potential range. These results suggest that the new method is superior to conventional formation.
Thermally regenerative ammonia-based batteries (TRABs) can be used to harvest low-grade waste heat as electrical power. To improve TRAB performance, a series of benzyltrimethyl quaternary ammonium-functionalized poly(phenylene oxide) anion exchange membranes (BTMA-AEMs) were examined for their impact on performance relative to a commercial AEM (Selemion AMV). The synthesized AEMs had different degrees of functionalization (DF; 25% and 40%), and thicknesses (50, 100 and 150 μm). Power and energy densities were shown to be a function of both DF and membrane thickness. The power density of TRAB increased by 31% using a BTMA-AEM (40% DF, 50 μm thick; 106 ± 7 W m−2) compared to the Selemion (81 ± 5 W m−2). Moreover, the energy density increased by 13% when using a BTMA-based membrane (25% DF, 150 μm thick; 350 Wh m−3) compared to the Selemion membrane (311 Wh m−3). The thermal-electric conversion efficiency improved to 0.97% with the new membrane compared to 0.86% for the Selemion. This energy recovery was 7.0% relative to the Carnot efficiency, which was 1.8 times greater than the highest previously reported value of a system used to capture low-grade waste heat as electricity.
A new design of lithium ion batteries with tunable mechanical properties has been developed. Depending on the material design of the battery components, the battery can range from elastic to structurally rigid. Elastic battery electrodes have been fabricated by utilizing elastic polymer binders in the electrode construction. The design of structural batteries capable of carrying load is based on a fiber reinforced polymer composite structure. The first generation structural battery has been fabricated based on a high molecular weight polyvinylidene fluoride (PVDF) matrix achieving a modulus of 3.1GPa and an energy density of 35Whkg−1. Remaining challenges in fully realizing a multifunctional structural battery are outlined.
Gulonolactone oxidase (GLO) is the enzyme responsible for the last step of ascorbic acid biosynthesis. The aim of this study was to investigate the effect of dietary α-tocopherol and ascorbic acid on GLO activity in a lower vertebrate, the white sturgeon (Acipenser transmontanus). Both α-tocopherol and ascorbic acid modulated renal GLO activity. The increase of dietary levels of α-tocopherol and/or ascorbic acid significantly raised the liver concentrations of these two antioxidants and concomitantly lowered kidney’s GLO activity. The results suggest that the enzyme of ascorbic acid synthetic pathway responded to the animal’s antioxidant status and that its activity was downregulated by α-tocopherol. This is the first record of α-tocopherol being involved in the regulation of ascorbic acid synthesis. This new observation may provide a hypothesis for the evolutionary loss of GLO expression in teleost fishes.