batterydata/paper-abstracts huggingface dataset:
A screen-printing process is used to prepare thick Zr-incorporated LiCoO2 (Zr–LiCoO2) films up to 20μm. The sol slurry used for the screen-printing consists of a Zr–LiCoO2 sol and the Zr–LiCoO2 powder. The microstructure and morphology of the films are investigated. After a thermal treatment, crack-free crystalline films are obtained. The electrochemical properties of the thick films are investigated in a half-cell with a Li-metal anode and in a full-cell with a Fe/Si multilayer film anode. Excellent cycleability is observed. Incorporation of 5wt.% Ag powder into the sol slurry for screen-printing improves the electrochemical performance such as the charge–discharge coulombic efficiency. This is attributed to enhanced electrical conductance. It is found, however, that the degree of utilization of the electrode material decreases with increasing film thickness.
The γH2AX focus assay, based on phosphorylation of the variant histone protein H2AX, was evaluated as a genotoxicity test in immortalised wild-type mouse embryonic fibroblasts (MEFs) treated for 4h with a panel of reference compounds routinely used in genotoxicity testing. The topoisomerase II poison etoposide (0.006–60μg/ml), the alkylating agent methyl methanesulfonate (1.3–65μg/ml) and the direct DNA-damaging agent bleomycin (0.1–10μg/ml) all produced a positive concentration–response relationship. The non-genotoxic compounds ampicillin (0.035–3500μg/ml) and sodium chloride (0.058–580μg/ml) showed no such response with increased concentrations. The H2AX phosphorylation results were compared with the outcome of two standard in vitro genotoxicity tests, namely the micronucleus and comet assays. Compounds that produced measurable DNA damage in the focus assay generated micronuclei at comparable concentrations. In this study, the focus assay identified genotoxic agents with the same specificity as the comet assay. These results were substantiated when H2AX phosphorylation was analysed using flow cytometry in the murine cell line L5178Y, growing in suspension. The data were in concordance with the manual scoring focus assay. To further this investigation, the γH2AX flow cytometry was compared to the in vitro micronucleus flow cytometry and mouse lymphoma assay using the same cell population after MMS treatment. The median γH2AX value increased significantly above the control at all four MMS concentrations tested. The percentage of micronucleus events in the in vitro micronucleus flow test and the mutation frequency in the mouse lymphoma assay were also significantly increased at each MMS concentration. The current data indicate that H2AX phosphorylation could be used as a biomarker of genotoxicity, which could predict the outcome of in vitro mammalian cell genotoxicity assays.
This paper presents a comparative study on electrosorptive behavior of commercial single walled and double walled carbon nanotubes (CNTs) and as-prepared graphene as potential electrode materials for capacitive deionization (CDI). Their electrosorptive behaviors are evaluated under the same experimental conditions and described by various adsorption isotherms and kinetics models. It was found that the electrosorptive capacity of CNTs (single walled or double walled)-based CDI is higher than that of graphene-based CDI, which is related to their specific surface area, pore structure and hydrophilic functional groups. Electrosorptive kinetics analysis further confirms that CNTs are more suitable as electrode materials than graphene.
On the basis of the crystal phase evolution from β-Ni(OH)2 to α-Ni(OH)2, α-Ni(OH)2, β-Ni(OH)2, and their mixed-phase structures were selectively crystallized at different stages during the hydrolysis of Ni(Ac)2 at hydrothermal conditions. We used both XRD characterization and SEM observation to clearly identify such a transformation process. Electrochemical tests indicate that the mixed-phase Ni(OH)2 obtained at 3h possesses the best capacitive performance among all as-obtained samples such as initially formed β-Ni(OH)2 nanosheet aggregates, mixed-phase Ni(OH)2 obtained at other reaction stages, and the ultimately formed α-Ni(OH)2 nanobelts. This phase selective route provides us an effective way to investigate the correlation between crystal phase composition of electrode materials and their capacitive performance.
Owing to its low cost and high volumetric capacity, Mg is a promising anode material for energy storage applications. Previous research has identified the cathode chemistry as a major challenge that must be addressed for further development of Mg-based batteries. In response to this challenge, here we show Br2-based conversion chemistry is a potential route toward rechargeable Mg-batteries. Compared with Mg-ion or Mg-air chemistries, the Mg-Br2 system features fast kinetics and good cyclability. To solve the issues of poor electrolyte stability, a non-aqueous, dual-electrolyte scheme was employed for this proof-of-concept demonstration. The anolyte consisted of Mg(TFSI)2 dissolved in a monoglyme and diglyme mixture. The catholyte was composed of Mg(TFSI)2 in PYR14TFSI ionic liquid mixed with active bromine species. When Mg was used as the anode, an open circuit voltage of 3.0V (vs. Mg2+/Mg) was measured. The prototypical cell was successfully discharged and charged for over 20 cycles with consistently high coulombic efficiencies (ca. 96%).
A previous study is focused on high temperature cycling of industrially manufactured Li-ion pouch cells (NMC-111/Graphite) with different electrolytes at 80 °C [JPS 373 (2018) 172–183]. Within this article the same test set-up is used, with cells stored for 30 days at different open circuit potentials and various electrolytes instead of electrochemical cycling. The most pronounced cell degradation (capacity fade and resistance increase) happens at high potentials. However appropriate electrolyte formulations are able to suppress ageing conditions by forming passivating surface films on both electrodes. Compared with electrochemical cycling at 80 °C, cells with enhanced electrolytes only show a slight resistance increase during storage and the capacity fade is much lower. Additionally it is shown for the first time, that the resistance is decreasing and capacity is regained once these cells are cycled again at room temperature. This is not the case for electrolytes without additives or just vinylene carbonate (VC) as an additive. It is further shown that the resistance increase of cells with the other electrolytes is accompanied by a reduction of the cell volume during further cycling. This behaviour is likely related to the reduction of CO2 at the anode to form additional SEI layer components.
Apatites are a very important class of functional materials that exhibit a range of stoichiometries and crystal structures. The oxygen diffusion mechanisms and activation energies in these materials are highly influenced by the composition and crystal structure. We review recent investigations on apatites with a focus on their self-diffusion properties as these are important for their potential application as electrolytes in solid oxide fuel cells.
Three-dimensional C@CoO@graphene composite with hollow carbon core and graphene outer layer is fabricated. Benefiting from the coverage of graphene oxide structure, the porous CoO layer can be stabilized and formed between carbon layer and graphene structure. The special nanocomposite exhibits high reversible capacity, good rate capability at high current densities and long-life performance, and retains a high capacity of 861 mAh g−1 at 500 mA g−1 over 700 cycles, making it a promising anode material for Li-ion batteries (LIBs).
Sn–Ni alloy films were prepared by annealing tin-coated nickel foils at 463K for 0–25h, and their charge–discharge characteristics as negative electrodes for sodium secondary batteries were studied in an intermediate temperature ionic liquid Na[FSA]–K[FSA] (FSA=bis(fluorosulfonyl)amide) at 363K. As a result, a Sn–Ni film without annealing retained a reversible capacity of 343mAh (g-Sn)−1 after 100 charge–discharge cycles. In contrast, the annealed films had lower capacities and poorer cycleability. Possible mechanisms to understand the cycling performance were identified by X-ray diffraction and field-emission scanning electron microscopy studies.
In recent years, silicon (Si) and germanium (Ge) materials have been considered as promising high-performance anode materials for lithium-ion batteries due to their high theoretical capacities. It is of great importance to design and synthesize micro/nanostructured Si and Ge materials. In this work, we demonstrated that Si, Ge and SiGe micro/nanowires can be continuously synthesized from their oxides precursors through molten salt electrodeposition. The electrochemical synthesis processes have been investigated systematically, and the deposited Si, Ge and SiGe micro/nanowires have been characterized and compared. The results show that the micro/nanostructured Si and Ge materials with tunable morphology can be facilely and continuously produced via molten salt electrodeposition. The electrodeposition process generally includes calcium oxide-assisted dissolution and electrodeposition processes, and the morphologies of the deposited Si and Ge products can be controlled by varying conditions. Si micro/nanowires, Si films, Ge micro/nanowires, and Ge particles can be continuously synthesized in a controlled manner.
With increasing the applications of lead-acid batteries, the demand for efficient, low resistant and inexpensive batteries has increased drastically. As discharge rates increase, ohmic voltage losses in current collecting system become more important. In this study, numerical methods are employed to investigate the effect of grid configuration, lug position, diagonal wire angles and tapering wires towards the plate’s lug on the performance of positive electrode of lead-acid batteries via modeling the current and potential distribution through gird wires, active material and adjacent electrolyte to the surface of each grid. 18 distinct grid designs with same weights are designed to achieve this task. The results indicate that double-diagonal configuration offers up to 43% increased current distribution uniformity. It is also shown that locating the lug near the midpoint of the frame, increasing the degree of parallel diagonal wires and tapering the wires towards the lug increases the uniformity of the current distribution up to 14%, 1.6% and 5.6%, respectively. It is noteworthy that manufacturing and practical limitations has been taken into account in this work as well.
A N-methylpyrrolidone (NMP) assisted electrochemical deposition route has been developed to realize the synthesis of a dense α-Co(OH)2 layered structure, which is composed of nanosheets, each with a thickness of 10nm. The capacitive characteristics of the as-obtained α-Co(OH)2 are investigated by means of cyclic voltammetry (CV), charge/discharge characterization, and electrochemical impedance spectroscopy (EIS), in 1M KOH electrolyte. The results indicate that α-Co(OH)2 prepared in the presence of 20vol.% NMP has denser and thin layered structure which promotes an increased surface area and a shortened ion diffusion path. The as-prepared α-Co(OH)2 shows better electrochemical performance with specific capacitance of 651Fg−1 in a potential range of −0.1 to 0.45V. These findings suggest that the surfactant-assisted electrochemical deposition is a promising process for building densely packed material systems with enhanced properties, for application in supercapacitors.
Battery management systems (BMS) are responsible for the reliable and safe operation of lithium-ion battery packs in electric vehicles (EVs). State-of-Charge (SoC), State-of-Health (SoH) and State-of-Available-Power (SoAP) are the major battery states that must be determined by means of so-called monitoring algorithms. In this study, a comparative study of a wide range of impedance-based equivalent circuit models (ECMs) for on-board SoAP prediction is carried out. In total, seven dynamic ECMs including ohmic resistance, RC-elements, ZARC-elements connected in series with a voltage source are implemented. The investigated ECMs are verified under varying conditions (different temperatures and wide SoC range) in a model-in-the-loop (MiL) environment using real vehicle data obtained in an EV prototype and current pulse tests. In this context, LIBs at different aging states using various active materials (NMC/C, NMC/LTO, LFP/C) are investigated. Furthermore, the current dependence of the charge transfer resistance is considered by applying the Butler-Volmer equation. The dependence of voltage estimation and SoAP prediction accuracy for different prediction time horizons on SoC, temperature and applied current rate is examined comprehensively.
With a new cell design, simultaneous electrochemical–ESR–conductivity measurements were realized for the first time. A detailed picture of the potential dependences of the ESR signal and conductance of polyaniline was thus obtained, suggesting that the conduction mechanism could be well interpreted in the framework of the polaron lattice model. Besides, the ESR saturation data obtained in this work provided new experimental evidence for the transformation between Curie and Pauli spins with potential change.
Lithium vanadate, LiVO3, has been successfully synthesized by a soft chemistry route with subsequent calcinations. The influence of synthesis temperature on the structure properties including lattice parameters and crystallite size were investigated by X-ray powder diffraction. The LiVO3 compound fabricated at 350 °C has the smallest particles with diameters ranging from 500 nm to 1 μm, and possesses the best performance including high discharge capacity, good rate capability and cyclic stability as cathode materials for lithium ion batteries. Highly stable specific capacities of 257, 233, 203.8, 173.7 and 141.9 mA h g−1 can be achieved at current densities of 100, 200, 400, 800 and 1500 mA g−1, respectively. The phase transition of the discharged electrode has been evaluated by the ex-situ XRD techniques. Electrochemical impedance spectra (EIS) measurements were carried out to determine the influence of phase transition on the lithium diffusion coefficients.
This chapter provides a review of studies assessing the changes that occur in different memory systems and processes from young adulthood to old age. The evidence reviewed indicates interesting differential patterns of development in adulthood and old age that depend on different factors, including the task and the memory type involved. Several theoretical accounts at different levels of generality that have been suggested to explain the age-related patterns of memory development, and especially of episodic memory deficits, are discussed. Finally, a unified approach is suggested that may serve as a departure point to further advance our knowledge of age-related changes in memory.
Energy is a vital input for social and economic development. As a result of the generalization of agricultural, industrial and domestic activities the demand for energy has increased remarkably, especially in emergent countries. This has meant rapid grower in the level of greenhouse gas emissions and the increase in fuel prices, which are the main driving forces behind efforts to utilize renewable energy sources more effectively, i.e. energy which comes from natural resources and is also naturally replenished. Despite the obvious advantages of renewable energy, it presents important drawbacks, such as the discontinuity of generation, as most renewable energy resources depend on the climate, which is why their use requires complex design, planning and control optimization methods. Fortunately, the continuous advances in computer hardware and software are allowing researchers to deal with these optimization problems using computational resources, as can be seen in the large number of optimization methods that have been applied to the renewable and sustainable energy field. This paper presents a review of the current state of the art in computational optimization methods applied to renewable and sustainable energy, offering a clear vision of the latest research advances in this field.
As described in NIST Tech Beat, The National Institute of Standards and Technology (NIST) has submitted to Congress the annual report of activities under the National Construction Safety Team (NCST) Act, which authorizes the agency to conduct technical investigations of major building failures in the U.S. Although NIST did not conduct any new investigations of structural failures during the past year, the 2007 NCST report details significant progress in both the private and public sectors acting on NIST’s previous investigation-driven recommendations for improvement in building and fire standards, codes, and practices. Those recommendations stem from NIST’s investigations into the failure of the two World Trade Center (WTC) towers following the terrorist attacks of Sept. 11, 2001, and The Station nightclub fire in Rhode Island on Feb. 20, 2003, that killed 100 people.
Hydrogen production from electrochemical water splitting represents a highly promising technology for sustainable energy storage, but its widespread implementation heavily relies on the development of high-performance and cost-effective hydrogen evolution reaction (HER) electrocatalysts. Metal oxides, an important family of functional materials with diverse compositions and structures, were traditionally believed inactive towards HER. Encouragingly, the continuous breakthroughs and significant progress in recent years (mainly from 2015 onwards) make engineered metal oxides emerge as promising candidates for HER electrocatalysis. In this article, we present a comprehensive review of recent advances in metal oxide-based electrocatalysts for HER. We start with a brief description of some key fundamental concepts of HER, such as mechanisms, computational activity descriptors, and experimental parameters used to evaluate catalytic performance. This is followed by a overview of various types of metal oxide-based HER electrocatalysts reported so far, including single transition metal oxides, spinel oxides, perovskite oxides, metal (oxy)hydroxides, specially-structured metal oxides and oxide-containing hybrids, with special emphasis on designed strategies for promoting performance and property–activity correlation. Finally, some concluding remarks and perspectives about future opportunities of this exciting field are provided.
LiFePO4 thin films have been prepared by pulsed laser deposition method on titanium substrates. The influence of the deposition parameters, e.g. substrate temperature, ambient argon pressure, and post-annealing on the crystallinity and morphology of as-deposited thin films are investigated. Well-crystallized pure olivine-phase is obtained under optimized deposition condition (20–30Pa, 500°C). It shows a high electrochemical activity (83% theoretical capacity) at low current density (0.33μAcm−2, 1/20C) and elevated testing temperature (45°C). Moderate post-annealing treatment can enhance the utilization of the films further. The deposition of the film at a too high temperature or post-annealing for too long time could introduce Fe3+ impurities, i.e., Li3Fe2(PO4)3 and Fe4(P2O7)3, which can be easily detected by extending the electrochemical test voltage down to 2.5V.
Cubic spinel Li2ZnTi3O8 is a promising lithium ion battery electrode anode material with high specific lithium-intercalation capacity and low discharge voltage platform. Herein, Li2ZnTi3O8 anode materials are synthesized through solid state reaction, molten salt route, and sol–gel method, respectively. Sol–gel formed Li2ZnTi3O8 exhibits good crystallinity from XRD and agglomeration is alleviated with uniform particle size and more stack holes from SEM images compared with other methods. Cyclic voltammograms (CV) results show that the sol–gel formed Li2ZnTi3O8 electrode has the lowest polarization, indicating better kinetic process. Electrochemical impedance spectroscopy (EIS) reveals that the sol–gel formed Li2ZnTi3O8 sample exhibits highest electronic conductivity and faster lithium ion diffusivity in all three samples. The sol–gel formed Li2ZnTi3O8 electrode has excellent long-term cycling performance and high discharge capacities of 71.2, 90.9, and 150.0mAhg−1 after 1000 charge–discharge cycles with low capacity fadings of only 0.058%, 0.051%, and 0.028% per cycle, at 3000, 2000, and 1000mAg−1, respectively. These results show that sol–gel formed Li2ZnTi3O8 is a promising anode electrode material for high performance lithium ion batteries.
Ion doping strategy is employed to improve the rate performance of insulated Na3V2(PO4)2F3 (NVPF) as cathode of sodium ion batteries. The concepts of VSU-doping (the valence state of the doping ion keeps unchanged during the synthesis) and VSC-doping (the valence state changes during the synthesis) have been introduced in this research. Titanium with different valence states (Ti2+, Ti3+, Ti4+) is selected as the doping element to investigate the VSU-doping and VSC-doping effects on NVPF for the first time. Based on a series of characterizations, it is verified that a moderate Ti doping is able to effectively improve the rate performance of NVPF through the enhancing of electron conduction and sodium ion diffusion, and the advantage is more obvious for the VSC-doping samples. Among all the NVPF - Ti 0.1 x + (x = 2, 3, 4) samples, the NVPF - Ti 0.1 2 + treated with a VSC-doping (Ti source: TiO) possesses the minimum particle size distribution (~40 nm), exhibits the highest initial specific capacity of 125 mA h g-1 at 0.2 C, and a very high rate capability (104 mA h g-1 at 40 C, 81 mA h g-1 at 80 C, 41 mA h g-1 at 200 C) as well, which has surpassed most of the reported results. When coupling with Na3V2(PO4)3 (NVP) as the anode, the NVPF - Ti 0.1 2 + -NVP pseudo-symmetric full cell shows a high initial specific capacity of 99.6 mA h g-1 at 0.2 C and an outstanding rate capability (60% of initial specific capacity at 40 C). Subsequently, a detailed investigation on the effects of the VSU-doping and VSC-doping processes on the battery performance, in combination with DFT calculations and analysis of kinetic properties, has been conducted, especially from the perspective of electron conduction and sodium ion diffusion.
A methodology is presented to quantify acid stratification in flooded lead acid batteries and compare different types of batteries regardless of their design features and size by means of the proposed “stratifiability index”. This index describes to what degree acid stratification develops in flooded lead acid batteries. Different test procedures are proposed which induce severe acid stratification within 48 h and lead to significantly different degrees of acid stratification. The test procedures are intended to assist in the development and selection of batteries which are less prone to develop severe acid stratification.