batterydata/paper-abstracts huggingface dataset:
Electrochemical reaction of Ag+ in the interlayer of various layered oxides was investigated in this study. Intercalation of Ag+ into the interlayer of layered oxides was carried out with layer-by-layer self assembly (LBL) method. Film deposition with LBL method was monitored by UV–vis spectra. Ag+ intercalated layered oxide films showed very unique characteristics when compared to other similar Ag+ exchanged zeolite and clay electrodes. First of all, the peaks are very sharp and clear, which shows that the redox reaction in the interlayer is fast. In addition, there is an energy gap between the onset potentials of redox reactions, which is different from the behavior of other electrodes. The formation of the energy gap was assigned to the energy barrier in the host layer. Furthermore, pH and scan rate controlled experiments showed that the reaction has diffusion controlled mechanism and diffusion of H+ or K+ into interlayer is believed to be contributing to the redox reaction indirectly. The slope of I p versus ν 1/2 curves shows that redox reaction is reversible. The unique electrochemical behavior of the Ag+ intercalated layered oxide thin films may lead into the design of new nanocells using the potential energy difference between two different redox couple.
A 40-μm-thick, self-supporting, transparent film was obtained upon slowly evaporating an aqueous mixture of synthetic hectorite, Pt(NH3)2Cl2, and polyethylene oxide (PEO). The resulting film containing 2.4 wt.% platinum was then reduced under H2 at 150 °C for 2–4 h, turning black upon reduction. XRD shows development of Pt(0) by the appearance of crystalline peaks upon reduction. A lineshape analysis using the Scherrer equation of the (220) peak shows Pt(0) particles from 3.8 nm to 7.5 nm depending upon processing conditions. These values are confirmed by TEM, and a high dispersion of the metal throughout the matrix is evident. XRD and TGA confirm that PEO is stable to the processing conditions. In situ small-angle X-ray scattering measurements of the reduction process were also performed. Under an inert, non-reducing atmosphere, the shape of the scattering curve does not change as the temperature is raised from 30 °C to 150 °C. Analysis of the scattering curves using the general unified fit (GUF) equation yields one Rg value of 80 Å from 30 to 150 °C under He, which is assumed to arise from the overall film morphology. Under H2, however, the shape of the scattering curves visually changes between 100 and 120 °C. Two structural levels are needed to fit these curves at moderate temperatures in the GUF equation, with two subsequent Rg values. One of these Rg values corresponds to the film morphology (Rg=80–90 Å), while the other has an Rg=18–19 Å with a corresponding diameter of 4.8–5.1 nm. This latter Rg is assumed to arise from the reduced Pt(0) nanoparticles that form in situ during reduction.
The cathode active materials Li[Ni0.6Co0.2Mn0.2]O2 are synthesized using different inorganic salts, sulfate [NiSO4·6H2O, CoSO4·7H2O, MnSO4·H2O], nitrate [M(NO3)2·6H2O (M = Ni, Co, Mn)] and acetate [M(CH3COO)2·4H2O (M = Ni, Co, Mn)]. The X-ray diffraction (XRD) patterns indicate that sulfate and nitrate starting materials formed a well-ordered hexagonal α-NaFeO2 layered structure (space group: 166, R 3 ¯ m ) . However, acetate starting material is led to a poorly layered structure compared to the other materials. Field emission scanning electron microscope (FE-SEM) images show that sulfate and acetate starting materials formed nano-sized primary particles with a size of about 200–500 nm and 300 nm, and void channels. However, the primary particles with a size of 300 nm from nitrate starting material agglomerate together to form micro-sized secondary particles. The initial discharge capacities of the sulfate, nitrate, and acetate starting materials are 138.3, 142.4, and 135.9 mAh g−1 at 1 C-rate in the voltage range 3.0–4.3 V vs. Li/Li+, respectively. The discharge capacity retentions of sulfate, nitrate, and acetate starting materials are 92.5%, 63.9%, and 78.1% at 1 C-rate after 50 cycles, and 83.2%, 48.0%, and 71.7% at 6 C-rate after 100 cycles, respectively.
With the aim to enhance the performance of pseudo-capacitor electrode materials, a novel free-standing hybrid electrode through integrating vertically aligned sodium dodecyl benzene sulfonate (SDBS) intercalated NiCo LDH nanosheets and carbon fiber cloth (CFC) was synthesized via a one-step hydrothermal method. The SDBS could serve as NiCo LDH growth regulator and interlayer distance expander. Upon SDBS intercalation the LDH interlayer space increase from 0.79 nm to 1.52 nm, the enlarged interspace could significantly facilitate the ion transportation and boost the specific electrochemical performance. Moreover, the as-prepared NiCo-SDBS-LDH@CFC hybrid material delivers an excellent specific capacity of 748.2 C g−1 at 0.5 A g−1 and outstanding rate capacity of 78.9% at 10 A g−1. Contributed by the delicately engineered electrodes, a high performance of asymmetric supercapacitor (ASC) is constructed, which exhibited a high energy density of 70.94 Wh kg−1 at a power density of 400 W kg−1, the energy density can still remain as high as 59.11 Wh kg−1 at a high power density of 8000 W kg−1. Furthermore, the ACS cell manifests a long lifespan of 89.96% capacitance retention at 10 A g−1 even after 10000 cycles. This work not only demonstrates an attractive strategy for rational design and modification of LDH-based electrodes, but also provides superior nanostructured free-standing electrodes for high energy density supercapacitors.
Near space airships have gained widespread attention owing to the unique characteristics of long endurance at high altitudes; because of this characteristic, such airships have great potential for use in the fields of communication relay, early warning, earth observation etc. Near space airships can substitute near-earth geostationary satellites owing to the advantages of high load and long endurance at altitude exceeding 20 km. Buoyancy against gravity is generated by the airship hull, which is completely filled with helium, while the near space airship is equipped with an electrical propulsion system powered by solar energy. Unlike conventional aircraft, nearspace airships are a new type of vehicles with less design experience; coupled multi-disciplinary problems related to aerodynamics, structure, energy, control, etc. exist. With the aim of finding a solution for optimal near-space airship design, this study proposed a design using a multidisciplinary design optimization method.
While increasing worldwide energy consumption demands for better storage devices, the environmental impact of these is often neglected. More sustainable energy storage in terms of greener battery materials would be desirable. In this regard, bioderived quinone containing molecules may serve as active battery material. Here, dopamine, among others an important neurotransmitter or active in mussel adhesion, is copolymerized with pyrrole to form a rod-like mixed copolymer. n-type charge storage in the quinone functionalities is combined with p-type charge storage in the conjugated doped polymer backbone from pyrrole and dopamine units with decreased polaron delocalization length compared to neat polypyrrole. The resulting sustainable polymer can be used as a cathode material due to a favorable redox potential of approx. 3.0–3.5 V vs. Li+/Li. It can reversibly store 160 mA h g−1 at a discharging rate of 100 mA g−1 and hence achieve similar capacities than inorganic, unsustainable, cathode materials and significantly higher capacities than other sustainable cathodes. Capacity is stable for more than 50 cycles, and even at high discharging rate of 800 mA g−1, approximately 90 mA h g−1 are reversibly stored with coulombic efficiency of almost 100%.
Examples of the effect of changes in separator saturation on the discharge performance and recharge effectiveness of valve-regulated lead-acid cells are given. Low-rate discharge performance decreases linearly with saturation. With the change in conductivity being distinctly non-linear, however, the high-rate capacity decreases substantially at low saturation. Cells become increasingly difficult to recharge effectively below critical saturation levels. These changes are influenced by the distribution of electrolyte within the separator. Using a simple model, the influence of the separator structure is examined. Low-rate capacity is independent of separator structure, consistent with it being able to wick electrolyte to the full height of the cell without significant variation of saturation. The preferred structure for a stable high-rate performance is low tortuosity, high anisotropy, and a low bulk density. Conversely, the recharge efficiency is best maintained as cells dry out with a structure having high tortuosity, minimum anisotropy, and small and uniform pore size. It is concluded that fibrous separators of this type should be designed according to the requirements of the application.
Vanadium phosphates have attracted considerable attention in Li-ion battery research because they feature the chemical activity of vanadium and the structural stability of phosphate. Novel LiVP2O7–Li3V2(PO4)3–LiVPO4F systems were synthesized through solid-state reaction, and the chemical reaction, phase formation, and phase structure change of LiVP2O7, Li3V2(PO4)3, LiVPO4F were investigated using TG–DTA, XRD, and TEM tests. Results indicate that Li3V2(PO4)3, LiVP2O7, and LiVPO4F coexist in samples sintered at 575°C, and the three phases transform into one other by changing the sintering temperature. Electrochemical tests show that different electrochemical performances can be obtained by regulating the contents of each phase (LiVP2O7, Li3V2(PO4)3, or LiVPO4F). The LiVP2O7–Li3V2(PO4)3 sample synthesized at 625°C shows much better electrochemical performance because of the synergistic effects between Li3V2(PO4)3 and LiVP2O7.
One-dimensional porous anhydrous cobalt oxalate nanorods are prepared via a facile water-controlled coprecipitate method followed by thermal annealing treatment under N2 at 300°C. The nanorods are characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. When evaluated as an anode material for lithium ion batteries, the nanorods exhibit high reversible specific capacity and excellent cycling stability (924mAhg−1 at 50mAg−1 after 100 cycles and 709mAhg−1 at 200mAg−1 after 220 cycles). This remarkable electrochemical performance is attributed to the one-dimensional porous nanostructure that can provide large electrode/electrolyte contact area and short lithium-ion diffusion pathway, meanwhile reduce the volume expansion during the repeated discharge/charge process.
Assessing quality of life (QOL) and health-related quality of life (HRQOL) in older adults is important. Yet, limited research is available on the stability of these constructs and the psychometric properties of QOL [e.g., Satisfaction with Life Scale (SWLS)] and HRQOL [e.g., Short-Form 12 Health Survey (SF-12)] measures in this population. Such knowledge is important for designing and interpreting interventions. We examined stability of QOL (SWLS) and HRQOL (SF-12) and their test–retest reliability, measurement error, and interpretability over 1 year in older Black and White women (n = 230). Stability and reliability were ascertained through paired sample t tests and intraclass correlation coefficients (ICCs). Standard error of measurement and coefficient of variation assessed measurement error. Smallest detectable change estimated score interpretability. QOL and HRQOL remained stable; ICC values indicated moderate reliability for the SWLS and SF-12 (SWLS = 0.73, SF-12 Physical Composite Summary = 0.69, SF-12 Mental Composite Summary = 0.58). Measurement error and interpretability estimates were similar for both the SWLS and SF-12. Interpretability estimates indicated a change in score of around 33 % may represent an important change. We provide novel data for selecting and interpreting QOL and HRQOL measures contributing to a better understanding of intervention efficacy.
The ionic conductivity of 78Li2S·22P2S5 glass-ceramics is investigated as a function of the phase and the amount of precipitated crystal produces by two-step heat treatment comprising controlled nucleation and growth stages. Crystallization kinetics of amorphous 78Li2S·22P2S5 is analyzed by differential thermal analysis, and the obtained results show that the maximum nucleation rate and crystal growth rate is achieved at 170 °C and 230 °C, respectively. The heat treatment process is optimized based on classical phase transformation theory, using the maximum nucleation rate and crystal growth rate. The optimized heat treatment consists of nucleation at 170 °C for 30 min followed by crystal growth at 230 °C for 3 h. Lithium ion conductivity is improved by 89% by using this treatment to control the crystallization kinetics.
Energy storage systems (ESS) have the potential to make a significant contribution to planning and operation practises in power systems. While ESS can be used to provide multiple benefits in the power sector, widespread use has been restricted by high technology costs, lack of deployment experience, and the barriers and uncertainties caused by the present electricity market and regulatory structures that were designed for conventional electricity systems. This paper reviews countries with high renewable targets and with significant current or planned ESS deployments to ascertain the common problems affecting the use of ESS on the grid, and to establish where changes have been made or proposed to the electricity market and regulatory frameworks. Three major problems were identified as the undetermined asset class for ESS and unbundled electricity system limiting stakeholders from determining and realising multiple ESS benefits; low electricity market liquidity and changing market conditions; and a lack of common standards and procedures for evaluating, connecting, operating and maintaining ESS. Based on the established barriers, recommendations to update or create policies, regulation and market arrangements to increase the viability and wider use of grid level ESS are discussed. The three key regulatory and policy recommendations were identified as an alignment of renewable policies to that of ESS; creating a separate asset class for ESS and associated rules for regulated and competitive operations; and standardising assessment frameworks, connection and operational procedures for the use of ESS. Finally, three main electricity market recommendations include updating rules to support simultaneous ESS operation across wholesale, ancillary services and capacity markets; updating market rules to allow compensation for flexible and highly accurate responsive demand and generation technologies, such as ESS; and updating market ancillary services energy requirements.
Multilayer Mo2CTx MXene is used as a precursor to produce molybdenum oxide (MoO2)-disordered carbon hybrid materials using a one-step CO2 oxidation. The composites show clear, short plateaus in the charge/discharge curves as well as reversible phase transition peaks in cyclic voltammetry for the resulting MoO2. The electrochemical measurements support the generation of the metal oxide in the resulting composite materials. The generation of molybdenum oxide from Mo2CTx is verified from the plateau in Li+ charge-discharge profile as wells as various characterizations of XRD, XPS, etc. The resulting MoO2 active material coated on a copper foil shows a Li-ion capacity of 323 mAh/g at 50 mA/g (0.1 C) and 180 mAh/g at 1 A/g (4.0 C) with 85% retention for approximately 300 cycles.
Objectives The United States Army sought to create a legally defensible, scientifically validated physical pre-employment screening test. The purpose of this study was to identify a single combination of predictor tests that would predict physical performance on all of the criterion measure task simulations relevant to the Combat Arms military occupational specialties. Design Concurrent validation. Methods Data from 838 (608 males, 230 females) soldiers who completed both the criterion measure task simulations of a military occupational specialty and up to 14 predictor tests were used in the development of the test batteries. Stepwise regressions were used to identify test batteries that significantly predicted performance on the criterion measure task simulations of the military occupational specialties. Results Three test batteries were developed based on different subsets of the predictor tests: Test Battery 1 consisted of the medicine ball put, squat lift, beep test, standing long jump, and arm ergometer (adjusted R2 =0.80–0.85, p< 0.01); Test Battery 2 consisted of the medicine ball put, squat lift, beep test, and standing long jump (adjusted R2 =0.79–0.80, p< 0.01); and Test Battery 3 consisted of the standing long jump, 1-minute push-ups, 1-minute sit-ups, 300m sprint, and Illinois agility test (adjusted R2 =0.55–0.71, p< 0.01). Conclusions Test Battery 2 was selected as the Army’s Occupational Physical Assessment Test. It was highly predictive of performance of the Combat Arms military occupational specialties, required no complex equipment, and covered a range of physical fitness domains.
The separation of rare earth elements, cobalt and nickel from NiMH battery residues is evaluated in this paper. Analysis of the internal content of the NiMH batteries shows that nickel is the main metal present in the residue (around 50% in weight), as well as potassium (2.2–10.9%), cobalt (5.1–5.5%), rare earth elements (15.3–29.0%) and cadmium (2.8%). The presence of cadmium reveals that some Ni–Cd batteries are possibly labeled as NiMH ones. The leaching of nickel and cobalt from the NiMH battery powder with sulfuric acid is efficient; operating variables temperature and concentration of H2O2 has no significant effect for the conditions studied. A mixture of rare earth elements is separated by precipitation with NaOH. Finally, solvent extraction with D2EHPA (di-2-ethylhexyl phosphoric acid) followed by Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) can separate cadmium, cobalt and nickel from the leach liquor. The effect of the main operating variables of both leaching and solvent extraction steps are discussed aiming to maximize metal separation for recycling purposes.
The effect of two different etching procedures with inorganic acids (HSE and CSE)—one using additionally strongly oxidising conditions due to the presence of CrO3 (CSE)—and consecutive storage conditions (dry methanol and air) for previous corundum blasted titanium surfaces is compared with respect to their wettability behaviour and the potential of the etching processes for removing remaining blasting material. The etching procedures result in distinct different surface morphologies. Whereas the HSE surface shows sub-mm to sub-μm structures but neither porosity nor undercuts, the CSE surface is extremely rugged and porous with structures protruding the more homogeneously attacked areas by several micrometers. By EDX analysis both remaining blasting material and chromium and sulphur from the etching treatment has been detected on the CSE surfaces only. Both surfaces states show super-hydrophilic behaviour immediately after etching and storage up to 28 days in dry methanol. Whereas contact with air does not change super-hydrophilicity for the CSE samples, wettings angles of the HSE samples increase within minutes and reach about angles of about 60° and 90° after one and 2 days exposure to air, respectively. The increasing hydrophobicity is discussed with respect to the formation of a surface coverage from hydrocarbons originating from aromatic compounds present in traces in air.
Rapid capacity fading of a graphite electrode was obtained with LiPF6/MFA electrolyte due to poor properties of solid electrolyte interphase (SEI). Vinylene carbonate (VC) was therefore applied to the MFA-based electrolyte as an SEI modification additive. The effects of VC concentration on the electrochemical properties of the graphite/Li half-cell were investigated at 25 and 60 °C. At 25 °C, the graphite electrode in MFA + 1% VC-based electrolyte showed good capacity retention of 300 mA h g−1 after 50 cycles, which was comparable with that in EC–DMC-based electrolyte; at 60 °C, the electrode in MFA + 3% VC-based electrolyte showed capacity retention of 240 mA h g−1 after 50 cycles, which was much better than that in EC–DMC-based electrolyte. Overabundant VC additives showed negative effects because of the formation of too-thick and/or too-dense SEI. DSC measurements were carried out to study the thermal behavior of MFA-based electrolyte coexisting with lithiated graphite. VC-containing MFA-based electrolyte still showed much better thermal stability than EC–DMC-based electrolyte. TG–MS analysis was performed on delithiated graphite cycled in MFA-based electrolyte containing different VC concentrations to analyze VC's effect on SEI formation. In summary, VC-added MFA-based electrolyte was a promising electrolyte for the development of safer Li-ion batteries, especially at elevated temperature.
Previous evidence suggests consumption of flavonoids, a sub-class of polyphenols, is associated with improved cognitive function across the lifespan. In particular, acute intervention of a flavonoid-rich wild blueberry (WBB) drink has been shown to boost executive function (EF), short-term memory and mood 2–6 h post-consumption in 7–10-year-old children. However, confirmation of the aspects of EF and memory susceptible to WBB ingestion is required, particularly during childhood, a critical period of neurological development. In addition, the child literature on berry flavonoid supplementation and cognition highlights the potential for such interventions to elicit positive benefits to real-world educational scenarios, such as reading, a complex ability which relies upon aspects of cognition already known to improve following WBB.
Thermochemical materials K2CO3, MgCl2 and Na2S have been investigated in depth on energy density, power output and chemical stability in view of domestic heat storage application, presenting a critical assessment of potential chemical side reactions in an open and closed reactor concept. These materials were selected based on a recent review on all possible salt hydrates, within the frame of a thermochemical heat battery and considering recent advances in heat storage application. Judged by gravimetric and calorimetric experiments in operating conditions and worst-case-scenario conditions, K2CO3 is recommended for both an open and closed system heat battery. The compound is chemically robust with a material level energy density of 1.28 GJ/m3 in an open system and 0.95 GJ/m3 in a closed system, yielding a power output of 283–675 kW/m3. Na2S and MgCl2 on the other hand are chemically not robust in heat storage application, although having a higher energy density, output power and temperature in one cycle.
Initial irreversible capacity loss in graphite electrodes was suppressed by 1,3,2-dioxathiolane-2,2-dioxide and its derivatives (cyclic sulfates) in propylene carbonate (PC) containing electrolyte. Cyclic voltammetry (CV) showed that cyclic sulfates were decomposed at higher potentials than that for electrolyte solvents. In galvanostatic charge and discharge measurement, first cycle efficiency was increased from 58.2% to 90.5% by the addition of 1,3,2-dioxathiolane-2,2-dioxide. Passivation films formed by cyclic sulfates were observed by X-ray photoelectron spectroscopy (XPS), FT-IR, and pyrolysis/GC/MS (pyro/GC/MS). These results indicate that the surface was covered by a PEO like polymer with the inner layer comprised of Li2S like compounds.