batterydata/paper-abstracts huggingface dataset:
A one-pot sol-gel method was modified through delaying gel curing by compositing Li3V2(PO4)3 with carbon. As a result, mesoporous carbon film inlaid with Li3V2(PO4)3 nanoclusters (named as LVP-C) was prepared to serve as cathode for the “non-consumable electrolyte type” and “internal serial hybrid type” Lithium-ion hybrid supercapacitor (LIHS). The LVP-C17 composite exhibited a considerably high initial discharge capacity of 128 mAh g−1 at 0.2C-rate, which was extremely close to the theoretical specific capacity. The BET specific surface area of the LVP-C17 composite is as high as 53.65 m2 g−1 and the Barret-Joyner-Halenda (BJH) pore-size-distribution curve displays that the pore sizes of the composite are mainly below 10 nm. The Raman test of the LVP-C17 composite mainly exhibits the graphitized carbon (SP2 hybridization) and a smaller R value (0.86), from which it can be inferred that the electronic conductivity of the composite is improved. The LIHS was designed by using LVP-C17 as cathode and active carbon (AC) as anode (LVP-C17//AC LIHS), which exhibited a higher energy density of 24 Wh kg−1 at a power density 405 W kg−1, with 77% specific capacitance retention after 1000 cycles in a wider voltage range of 0–2.7 V. Furthermore, even at higher power density of 2.03 kW kg−1, the energy density provided by the device can still retain 12.4 Wh kg−1. The device combines the electrochemical performance advantages of lithium-ion batteries (LIBs) with supercapacitors (SCs) and is comparable to the energy density and power density of currently commercially available Ni/MH batteries.
In order to utilize silicon wafer as electrode and substrate for integrated lithium-ion batteries, a composite film with in-situ formed porosity (lithium phosphorous oxynitride/tin oxide, LiPON/SnO2) is fabricated and directly exploited as the artificial solid electrolyte interphase film. Without the compromise of Coulombic efficiency, the capacity and cycle performance of silicon wafer are both developed, resulting from the reduced resistance and the dynamically stable coating. This work provides guidance to enhance the lithiation of bulk silicon, and the strategy of surface modification can be applied to other advanced materials or fields.
Lithium–sulfur (Li–S) batteries have attracted much attention in the field of electrochemical energy storage and conversion. As a vital part of the cathode electrode, the host materials of sulfur usually have a strong impact on the capacity, energy density, cycle life and Coulombic efficiency of Li–S batteries. With their unique physical and chemical properties, the rationally designed hollow nanostructures show conspicuous advantages as sulfur hosts, and have significantly improved the overall performance of Li–S cells. The scope of this review considers the unique structural advantages of hollow host materials for high-performance Li–S batteries, together with a summary of recent advances in the design and synthesis of various hollow micro-/nanostructures with controlled shapes, tailored shell structures and designed chemical compositions. Finally, we propose some emerging requirements of sulfur hosts which we hope will shed some light on the future development trend of hollow structures for advanced Li–S batteries.
Combination of a solvent–salt complex [acetonitrile(ACN)2–LiTFSI] with a hydrofluoroether (HFE) co-solvent unveil a new class of Li–S battery electrolytes. They possess stability against Li metal and viscosities which approach that of conventional ethers, but they have the benefit of low volatility and minimal solubility for lithium polysulphides while exhibiting an uncharacteristic sloping voltage profile. In the optimal system, cells can be discharged to full theoretical capacity under quasi-equilibrium conditions while sustaining high reversible capacities (1300–1400 mA h g−1) at moderate rates, and capacities of 1000 mA h g−1 with almost no capacity fade at fast discharge rates under selected cycling protocols. A combination of operando X-ray absorption spectroscopy at the S K-edge, and electrochemical studies demonstrate that lithium polysulphides are indeed formed in these ACN-complexed systems. Their limited dissolution and mobility in the electrolyte strongly affect the speciation and polysulphide equilibria, leading to controlled precipitation of Li2S.
This paper presents a hybrid power system suitable for powering electric cars, trains and aircraft especially under high fluctuated load demand. The hybrid system includes fuel cells (FC), batteries and supercapacitors (SCs). The energy management strategy (EMS) is a key factor to reduce the total hydrogen consumption and slow down the FC performance degradation. A new EMS based on a recent optimization technique named Salp Swarm Algorithm (SSA) is proposed taking into consideration that the load demand is fully satisfied within the constraints of each energy source. The main objective of the proposed strategy is to minimize the total hydrogen consumption of the system. To minimize the energy obtained from the FC, the energy supplied by the batteries and supercapacitors is maximized. The SSA is an efficient and simple optimizer that needs few numbers of control parameters to be adjusted compared to other optimization algorithms. In order to show the validity of the proposed approach, a comparative study with other conventional approaches such as classical proportional-integral control strategy, frequency decoupling, and state machine (FDSM) control approach, equivalent consumption minimization strategy (ECMS), external energy maximization strategy (EEMS), and genetic algorithm (GA) is presented. In this study, the capstones of the comparison are the total H2 consumption of the FC and the efficiency of the algorithm. The obtained results confirmed that the proposed SSA approach is superior and efficient than the other strategies.
We report the case of patient MN, diagnosed with frontotemporal dementia, who exhibited a severe impairment in writing letters and words in upper-case print in the face of accurate production of the same stimuli in lower-case cursive. In contrast to her written production difficulties, MN was unimpaired in recognizing visually presented letters and words in upper-case print. We find a modest benefit of visual form cueing in the written production of upper-case letters, despite an inability to describe or report visual features of letters in any case or font. This case increases our understanding of the allographic level of letter-shape representation in written language production. It provides strong support for previous reports indicating the neural independence of different types of case and font-specific letter-shape information; it provides evidence that letter-shape production does not require explicit access to information about the visual attributes of letter shapes and, finally, it reveals the possibility of interaction between processes involved in letter-shape production and perception.
The high capacity and optimal cycle characteristics of silicon render it essential in lithium-ion batteries. The authors have attempted to realize a composite material by coating individual silicon (Si) particles of a few micrometers in diameter with a silicon oxide film to serve as an active material in the anode and so optimize the charge–discharge characteristics of the lithium-ion battery. Particle coating was achieved using an inductively coupled plasma-chemical vapor deposition (ICP-CVD) process that realized a homogenous coating of silicon oxide film on each Si particle. The film was synthesized based on tetraethyl orthosilicate (TEOS), with hydrogen (H2) gas used as a reducing agent to deoxidize the silicon dioxide. This enabled the control of the silicon oxidation number in the layers produced by adjusting the H2 flow during the silicon oxidization deposition with ICP-CVD. The silicon oxide covering the Si particles included both silicon monoxide and suboxide, which served to optimize the charge–discharge characteristics. The authors have succeeded in realizing a favorable active material using Si which is abundant in nature in the anode of a lithium-ion battery with highly charged, optimized cycle properties.
Battery storage technologies have developed to the point that some are mature enough to serve as a generation resource. However, whether a battery can generate profits by interacting solely in energy markets is unclear. Meanwhile, FERC order 784 requires electricity exchange markets in the U.S. to install the necessary technical equipment for batteries to supply ancillary services [12]. We suggest that current economic studies on the battery energy storage system (ESS) are limited because they do not explore possibilities to use battery storage in ancillary (reserve) markets. Applying battery ESS to ancillary service could be profitable enough to cover investment costs. In this study, we consider a battery storage operator’s best strategy each day, using backwards induction. We analyze the storage device as an exhaustible resource with a limited number of charging cycles and operating years. Based on this approach, we build a revenue model to maximized the net present value of the battery energy storage system revenues by applying the three-staged-method employed by Shcherbakova et al. [14]. We found that the battery in unable to cover its costs, and it does not use all the cycles available in its lifetime. This result, however, may be a function of the limits of our analytical approach.
Stokes radii of V(IV) and V(V) species in concentrated sulfuric acid solutions were determined from their diffusion limited current densities on a rotating platinum disk electrode and the solution viscosity. In addition, V(IV) and V(V) species were estimated based on their solubility, UV-Vis spectra, and cyclic voltammetric data. The possible ion-pair formation of V(IV) cation with SO4 2− and/or HSO4 − and the spontaneous polymerization of V(V) at a low H2SO4 concentration were discussed.
An in situ electrochemical atomic force microscopy (EC-AFM) cell was developed to study surface and dimensional changes of individual Li x CoO2 crystals during lithium de-intercalation. Discrete Li2CO3 particles having 50–250nm in diameter and 5–15nm in height were observed on the surface of stoichiometric LiCoO2 crystals and they were shown to gradually dissolve into the LiPF6-containing electrolyte. The dimensional change of individual Li x CoO2 crystals along the c hex. axis was monitored in situ during lithium de-intercalation. Evidence of surface instability or structural instability was not found in Li x CoO2 single crystals upon de-intercalation to 4.2V versus Li.
This paper compares two theoretical positions regarding the mental representation of homophones: first, that homophones have one phonological word form but two grammatical representations (lemmas, e.g., Levelt et al., 1999; Dell, 1990), or second, that they have two separate phonological word forms (e.g., Caramazza et al., 2001). The adequacy of these two theoretical accounts for explaining the pattern of generalisation obtained in the treatment of homophone naming in aphasia is investigated. Two single cases are presented, where phonological treatment techniques are used to improve word retrieval. Treatment comprised picture naming of one member of a homophone pair using a phonological cueing hierarchy. A significant improvement in word retrieval was found for both the treated and the untreated homophones, while there was no improvement for phonologically and semantically related controls. It is argued that the data support a shared representation for homophones at the word form level. However, current theories cannot explain the pattern of generalisation found without the addition of a mechanism for repetition priming (e.g., suggested by Wheeldon and Monsell, 1992) and feedback between word form and lemmas to explain the results.
Despite many animals being positive in one or both of the immunological tests, indicative of a heavily infected herd, none of the animals showed clinical signs and only one cow was shown to be shedding bacteria. A cross-reaction with other mycobacteria might have caused some of the immunoreactions in these animals. It is also possible that the Norwegian red cattle breed is resistant to clinical infection with M. a. paratuberculosis.
Rechargeable lithium cells can be made with two different intercalation compounds as the positive and negative electrodes, which are safer than the battery technology using pure Li metal. In this paper, we present our study of the Li ion type battery that uses LiTi2O4 as the negative electrode, which is coupled with a strongly oxidizing intercalation compound, spinel LiMn2O4, as the positive electrode has been found to solve problems associated with the use of metallic lithium at the expense of lowering the overall cell voltage. Preliminary electrochemical data revealed that this Li ion type battery “LiMn2O4/LiTi2O4” exhibits a low performance in terms of capacity. Li cycling efficiency is examined with mixed solvents as electrolyte. With improvements in capacity, materials such as these could improve the over all performance of secondary lithium intercalation cells.
Objective: Repetitive transcranial magnetic stimulation (rTMS) is being investigated as a potential treatment for depression. Few studies have addressed the neurocognitive effects of a course of rTMS in severely depressed patients. We evaluated neurocognitive effects of a 1–4 week course (mean 3 weeks) of rTMS using an aggressive set of parameters, in 15 severely depressed subjects. Methods: A battery of neurocognitive tests relevant to attention, working memory-executive function, objective memory and motor speed were administered to 15 subjects with treatment-resistant major depression (unipolar and bipolar), before and after a course of rTMS. Mean z scores were computed for each of 4 cognitive domains and analyzed using repeated measures multivariate analysis of covariance. Significant interactions were further clarified using univariate analysis of variance. Results: There was no worsening of performance on any of the cognitive domains over the baseline-post rTMS period. On the contrary, evidence of modest but statistically significant improvement in performance was noted in working memory-executive function, objective memory and fine motor speed domains over the rTMS treatment period. Conclusions: There was no evidence of adverse neurocognitive changes over the baseline-post rTMS period in 15 treatment-resistant depressed subjects undergoing a 3 week (mean) trial of rTMS. Significant improvements in several domains observed over the rTMS treatment period could not be explained by improved mood. Practice effects as well as other factors potentially contributing to these findings are discussed. Significance: rTMS is being increasingly studied as a neurophysiological probe as well as for its potential antidepressive effects. The effects on neuronal function raise appropriate questions of safety of its use at varying stimulus parameters and durations. This study contributes to the small body of evidence of the cognitive effects of rTMS in severely depressed patients.
Abstract Based on thermodynamic calculations a potential/pH diagram for the Pb/H2SO4/H2O system is plotted. It defines the pH ranges of formation of the different phases and electrode systems, but the system Pb/H2SO4/H2O is kinetically controlled as well. During the anodic polarization of a lead plate immersed in sulfuric acid solution, the following electrode systems form: 1. Lead sulfate electrode (Pb/PbSO4) in the potential region from −0.97 to −0.40V versus Hg/HgSO4 reference electrode; 2. Lead oxide/lead sulfate electrode (Pb/PbO/PbSO4) at potentials from −0.40 to +0.95V; 3. Lead dioxide electrode (Pb/PbO2) at potentials above +0.95V. Pb/PbO/PbSO 4 electrode: In the lead oxide/lead sulfate potential region, a PbSO4 crystal layer forms first. It acts as a semipermeable membrane, which causes alkalization of the solution at the boundary between Pb and PbSO4 and the solution in the pores of PbSO4 layer. The Pb/PbO/PbSO4 electrode has photoelectrochemical properties, and when exposed to electrochemical oxidation above +0.95V, PbO is oxidized to α-PbO2 and PbSO4 to β-PbO2. Pb/PbO 2 electrode: Electrochemically obtained PbO2 contains crystal (PbO2) and hydrated (PbO(OH)2) (gel) zones. During discharge of the battery, the reduction of PbO2 proceeds in the gel zones by a proton–electron mechanism. On anodic polarization of the Pb/PbO2 electrode, oxygen is evolved. It penetrates through the PbO2 layer and oxidizes the lead, i.e., a corrosion layer of PbO and PbOn (1<n>2) forms. The lead alloy composition (i.e., Sb, Sn, Bi, Ag, As, and other additives) affects the rate of oxidation of PbO to PbO2 and the electrochemical properties of the corrosion layer. At high overvoltage of the Pb or PbO2 electrodes, hydrogen and oxygen evolve, and hydrogen (H+/H2) and oxygen (H2O/O2) electrode systems form. This chapter presents also general notes on lead–acid cell/battery design and on the technological schemes for battery manufacture.
Two-dimensional (2D) layered vanadium disulfide (VS2) is a promising anode material for lithium ion batteries (LIBs) due to the high theoretical capacity. However, it remains a challenge to synthesize monodispersed ultrathin VS2 nanosheets to realize the full potential. Herein, a novel solvothermal method has been developed to prepare the monodispersed bowl-shaped NH3-inserted VS2 nanosheets (VS2). The formation of such a unique structure is caused by the blocked growth of (001) or (002) crystal planes in combination with a ripening process driven by the thermodynamics. The annealing treatment in Ar/H2 creates porous monodispersed VS2 (H-VS2), which is subsequently integrated with graphene oxide to form porous monodispersed H-VS2/rGO composite coupled with a reduction process. As an anode material for LIBs, H-VS2/rGO delivers superior rate performance and longer cycle stability: a high average capacity of 868/525 mAh g−1 at a current density of 1/10 A g−1; a reversible capacity of 1177/889 mAh g−1 after 150/500 cycles at 0.2/1 A g−1. Such excellent electrochemical performance may be attributed to the increased active sites available for lithium storage, the alleviated volume variations and the shortened Li-ion diffusion induced from the porous structure with large specific surface area, as well as the protective effect from graphene nanosheets.
In this study, highly crystalline FeFe(CN)6 with metal-organic framework is synthesized and measured in NaNO3 and LiNO3. Electrochemical kinetics, physical and chemical changes about the insertion and extraction processes of sodium ions and lithium ions in FeFe(CN)6 are compared and discussed. Intriguingly, it exhibits a good electrochemical performance in sodium aqueous batteries, with a capacity of 118 mAh g−1 at 400 mA g−1, but a poor electrochemical behavior in lithium aqueous batteries. This study sheds light on the different insertion processes between sodium ions and lithium ions in FeFe(CN)6, that the outer petaloid-like structure forms on the surface of FeFe(CN)6 after Li ions insertion with little volume expansion, while FeFe(CN)6 after Na ions insertion could still maintain the cubic-like structure with lattice change. Different insertion mechanisms of sodium ions and lithium ions are proposed that hydrated Na ions could insert at interstitial sites, while hydrated Li ions are more likely to occupy large open sites due to the larger radius of hydrated Li ions than hydrated Na ions. Besides, insertion/extraction performance and capacitive preformance dominate in NaNO3 and LiNO3, respectively. These differences may lead to the different electrochemical behaviors between sodium-ion and lithium-ion aqueous batteries.
New poly(ethyl methacrylate) and poly(2-ethoxyethyl methacrylate) gel electrolytes containing immobilised lithium perchlorate solution in propylene carbonate were prepared by UV radical polymerisation. Materials exhibit high ionic conductivity up to 0.23mScm−1 and long-term stability of chemical and mechanical properties. Both materials keep their suitable conductivity above −20°C. The effect of material composition, temperature, cross-linking agent and salt concentration on the electrochemical and mechanical properties were studied using impedance spectroscopy and cyclic voltammetry. The accessible electrochemical window of both polymer electrolytes was estimated from −2.1 to 1.5V versus Cd/Cd2+. Impedance measurements showed almost one-order increase of conductivity when ethylene dimethacrylate was used as a cross-linking agent in comparison with the polymer electrolyte without agent.
Lithium–sulfur (Li–S) batteries have emerged as promising energy storage devices due to their high theoretical specific energy densities; their practical applications, however, have been restricted due to their poor cycling stability arising from the shuttle effect of the S cathode and dangerous Li dendrite growth. S and Li can be encapsulated into porous framework hosts to address these issues. Metal–organic frameworks (MOFs)/covalent-organic frameworks (COFs) have shown great potential due to their tunable frameworks, structural diversity, and functional versatility. In this review, the applications of MOFs/COFs for Li–S batteries in terms of the sulfur hosts, electrolyte containers, separators, and Li dendrite blocking barriers are systematically summarized. A short conclusion and outlook regarding future research opportunities for pristine MOFs/COFs for Li–S batteries are also provided.
Building plays a significant role for energy consumption and carbon dioxide emission in the United States. Extensive researches are conducted to develop effective operation strategy for the building system. However, less study is to investigate the energy sharing among a cluster of multiple buildings (aka building clusters) under uncertainty. In this research, we propose to develop a data-driven feed-forward decision framework for building clusters operation, through the use of noise-tolerant data fusion techniques. Three stages are implemented in the proposed framework which include: (1) decisions generation stage that employs an augmented multi-objective particle swarm optimization based decision framework to obtain operation decisions for the next future L hours; (2) execution stage that implements the first l hours decisions; and (3) calibration stage that employs data fusion techniques to calibrate the building clusters model in a l′ hour scale. The calibrated model is fed back to the decisions generation stage for the next period decisions. Unscented Kalman filter which is demonstrated to outperform other data fusion techniques in terms of accuracy, robustness and computational efficiency based on our experimental results is employed in the calibration stage. To evaluate the performance of the proposed framework, we compare the operation decisions with and without calibration stage. It is demonstrated that the proposed feed-forward framework can obtain operation decisions to achieve more cost savings. The impacts of different time lengths l in the execution stage are investigated which indicate the selection of l depends on the trade-offs between decision solution quality and computational performance.