batterydata/paper-abstracts huggingface dataset:
The detailed isothermal electrochemical model for a lithium ion cell has ten coupled partial differential equations to describe the cell behavior. In an earlier publication [Journal of Power Sources, 222, 426 (2013)], a reduced order model (ROM) was developed by reducing the detailed model to a set of five linear ordinary differential equations and nonlinear algebraic expressions, using uniform reaction rate, volume averaging and profile based approximations. An arbitrary current profile, involving charge, rest and discharge, is broken down into constant current and linearly varying current periods. The linearly varying current period results are generic, since it includes the constant current period results as well. Hence, the linear ordinary differential equations in ROM are solved for a linearly varying current period and an explicit algebraic algorithm is developed for lithium ion cell voltage prediction. While the existing battery management system (BMS) algorithms are equivalent circuit based and ordinary differential equations, the proposed algorithm is an explicit algebraic algorithm. These results are useful to develop a BMS algorithm for on-board applications in electric or hybrid vehicles, smart phones etc. This algorithm is simple enough for a spread-sheet implementation and is useful for rapid analysis of laboratory data.
Layered Ni-rich Li[Ni0.6Mn0.2Co0.2-x M x ]O2 cathode materials (x = 0, 0.05; M = Al, Fe, Sn) are synthesized via a co-precipitation synthesis route and the effect of dopants on the structure and electrochemical performance is investigated. All synthesized materials show a well-defined layered structure of the hexagonal α-NaFeO2 phase investigated by X-ray diffraction (XRD). Undoped LiNi0.6Mn0.2Co0.2O2 exhibits a discharge capacity of 170 mAh g−1 in Li-metal 2032 coin-type cells. Doped materials reach lower capacities between 145 mAh g−1 for Al and 160 mAh g−1 for Sn. However, all doped materials prolong the cycle life by up to 20%. Changes of the lattice parameter before and after delithiation yield information about structural stability. A smaller repulsion of the transition metal layer during delithiation in the Sn-doped material leads to a smaller expansion of the unit cell, which results in enhanced structural stability of the material. The improved structural stability of Sn-doped NMC cathode active material is proven by thermal investigations with the help of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).
Four series of solution and corresponding polymer gel electrolyte systems were studied. The systems were composed of a solvent (γ-butyrolactone (GBL) or propylene carbonate (PC)), (three different concentrations of) a lithium salt (LiBF4 or lithium bis(trifluromethanesulfonyl)-imide (LiTFSI, LiN(SO2CF3)2)), and poly(ethylene glycol diacrylate) of molecular weight 4000 (PEO), which was cross-linked to form the polymer gels. The self-diffusion coefficients of the lithium, the anions, the solvents and the polymer were obtained independently using 7Li, 19F and 1H pulsed-gradient spin-echo NMR measurements. From the individual diffusion coefficients of each component of the GBL–LiBF4, GBL–LiTFSI, PC–LiBF4, and PC–LiTFSI solutions and the corresponding polymer gel electrolytes, the solvation and the solvent-dependent behaviour of the lithium and the anions are clearly shown. Especially in the gels, the lithium binding with the PEO matrix were found to be quite different depending on whether the solvent was PC or GBL.
In current study, nanoparticles of NiS were synthesized by applying microwave radiation. The effect of concentration of sulfur source, reaction time, and power of microwave irradiation on the treatment process was investigated. The morphology, structure, and composition of the as-synthesized nanostructures have been confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties of as-prepared sample were investigated by photoluminescence spectroscopy; the emission peak is at 555.04nm and shows the blue shift.
The electrochemical performance of LiCoPO4-based electrodes was studied in dependence on synthetic conditions. The role of particle size distribution is illustrated. Structural changes occurring at lithium extraction–insertion were explored by ex situ and in situ synchrotron XRD measurements. For the samples annealed at temperature lower than 600°C the amorphisation of the cathode material was identified. For a high-temperature sample the two-phase character of electrochemical reaction was confirmed. The character of structural changes observed at charge and discharge is different: the two-phase reaction LiCoPO4–“CoPO4” occurs during charging, while discharge induces a strong increase of the cell volume for the Li-poor phase.
A multi-stack module consisting of a number of stacks connected in series and parallel serves as a basis for installation of MW-scale vanadium flow battery system in grid storage applications. Due to the existence of stack-to-stack variation in resistance, the module performance can be notably limited by an inappropriate module layout that magnifies the impact of stack resistance variation through series and parallel connections. To understand the layout effect on performance, an in-depth investigation is conducted for an eight-stack 250 kW module in this study. Based on experimental measurements, the correlation of module layout to performance is firstly revealed on both the 250 kW module and a laboratory mini-module. Subsequently, 35 different layouts are specified for the 250 kW module and their performance is fully evaluated by means of development of dynamic models for the module. Simulation results prove that the module charging capacity can be effectively improved by grouping stacks with similar resistances into the same branch and be further promoted by optimizing the flow rate for the stack with the largest resistance. The present study offers not only mechanistic insights into the importance of module layout but a cost-effective way to evaluate the module performance as well.
As a well-known traditional medicine, Angelica gigas (AG) and its active constituents, including decursin and decursinol, have been shown to possess several health beneficial properties such as anti-bacterial, immunostimulating, anti-tumor, neuroprotective, anti-nociceptive and anti-amnestic activities. However, there is lack of toxicity studies to assess potential toxicological concerns, especially long-term toxicity and genotoxicity, regarding the AG extract. Therefore, the safety of AG extract was assessed in subchronic toxicity and genotoxicity assays in accordance with the test guidelines published by the Organization for Economic Cooperation and Development. In a subchronic toxicity study for 13weeks (125, 250, 500, 1000 and 2000mg/kg body weight, delivered by gavage), data revealed no significant adverse effects of the AG extract in food consumption, body weight, mortality, hematology, biochemistry, necropsy, organ weight and histopathology throughout the study in male and female rats. These results suggest that no observed adverse effect level of the AG extract administered orally was determined to be greater than 2000mg/kg/day, the highest dose tested. In addition, a battery of tests including Ames test, in vitro chromosome aberration assay and in vivo micronucleus assay suggested that the AG extract was not genotoxic. In conclusion, the AG extract appears to be safe as a traditional medicine for oral consumption.
Spherical clusters of Ni(OH)2 nanosheets are directly grown on skeletons of nickel foam via a facile template-free spontaneous growth method. The obtained electrode (β-Ni(OH)2/Ni-foam) is characterized by X-ray diffractometry, scanning and transmission electron microscopy and thermal analysis. Results show that Ni(OH)2 has a β-phase structure and presents on the nickel foam skeleton mostly as spherical clusters with a diameter of ∼10μm. The spheres are composed of nanosheets with thickness of ∼60nm, width of ∼230nm and length up to ∼2μm, and the nanosheets are assembled by nanoparticles with diameter of ∼20nm. The electrochemical performance of the β-Ni(OH)2/Ni-foam electrode is evaluated by cyclic voltammetry and galvanostatic charge–discharge tests. The difference between the oxygen evolution reaction onset potential and the anodic peak potential for this electrode (∼100mV) is larger than that for β-Ni(OH)2 nanosheets and nanotubes powder electrode (∼65–77mV) and much larger than that for commercial spherical β-Ni(OH)2 powder electrode (∼25–47mV), indicating that the β-Ni(OH)2/Ni-foam electrode can be fully charged. The specific discharge capacity of β-Ni(OH)2 in the β-Ni(OH)2/Ni-foam electrode reaches 275mAhg−1, which is close to the theoretical value, lower than that of β-Ni(OH)2 nanotubes (315mAhg−1), but higher than that of nanosheets (219.5mAhg−1), commercial micrometer grade spherical powders (265mAhg−1) and microtubes (232.4mAhg−1).
γ-LiAlO2, Al2O3 and MgO were used as fillers in a PVdF-HFP polymer matrix to form self-standing, intrinsically porous separators for lithium-ion batteries. These separators can be hot-laminated onto the electrodes without losing their ability to adsorb liquid electrolyte. The electrochemical stability of the separators was tested by constructing half-cells with the configuration: Li/fibre-glass/filler-based separator/electrode. MgO-based separators were found to work well with both positive and negative electrodes. An ionic conductivity of about 4×10−4 S cm−1 was calculated for the MgO-based separator containing 40% 1 M solution of LiPF6 in an EC/DMC 1:1 solvent. Self-standing, lithium-ion cells were constructed using the MgO-based separator and the resulting battery performance evaluated in terms of cyclability, power and energy density.
The power system requires an additional amount of flexibility to process the large-scale integration of renewable energy sources. Community Energy Storage (CES) is one of the solutions to offer flexibility. In this paper two scenarios of CES ownership are proposed. Firstly, an Energy Arbitrage (EA) scenario is studied where an aggregator aims to minimize costs and CO 2 -emissions of an energy portfolio. Secondly, an Energy Arbitrage - Peak Shaving (EA-PS) scenario is assessed, which is based on a shared ownership between a Distribution System Operator (DSO) and an aggregator. A multi-objective Mixed Integer Linear Programming (MILP) optimization model is developed to minimize the operation costs and CO 2 -emissions of a community situated in Cernier (Switzerland), using different battery technologies in the CES system. The results demonstrate a profitable system design for all Lithium-ion-Batteries (LiBs) and the Vanadium Redox Flow Battery (VRFB), for both the EA and EA-PS scenarios. The economic and environmental performance of the EA-PS scenario is slightly worse compared to the EA scenario, due to power boundaries on grid absorption and injection to achieve peak shaving. Overall, the differences between the EA and EA-PS scenarios, in economic and environmental performance, are small. Therefore, the EA-PS is recommended to prevent problematic loads on the distribution transformer. In addition, the Pareto frontiers demonstrate that LiBs perform best on both economic and environmental performance, with the best economic and environmental performance for the Lithium-Nickel-Manganese-Cobalt (NMC-C) battery.
Aqueous Li-air batteries have attracted a great deal of attention due to their high theoretical energy capacities. However, while still in the early stages of research, the reported energy capacities of Li-air batteries are far from what has been theoretically predicted. In this research, we have designed a Li-air battery that has a Li ǀ organic liquid electrolyte ǀ Li+-conducting glass ceramic plate (LiGC plate) ǀ aqueous electrolyte ǀ Pt air electrode structure and studied the impacts of the compositions of the aqueous electrolyte on the battery performance. With lower concentrations of alkali aqueous electrolytes (≤0.05M LiOH), a discharge voltage of approximately 3.5V (at 0.05mAcm−2) and a voltage efficiency up to 84% were observed. The addition of LiClO4 into the aqueous solution slightly lowered the discharge voltage to 3.3V but dramatically decreased the internal resistance of the battery to 35.4Ωcm−2. With a charge voltage plateau observed at 3.90V at a current of 0.05mAcm−2, the Li ǀ organic liquid electrolyte ǀ LiGC ǀ 1M LiClO4 ǀ Pt air battery showed an 85% voltage efficiency at room temperature. Adding LiClO4 into the aqueous electrolytes resulted in an impedance reduction and slowed the pH increase of the alkaline-based electrolyte due to the fast or long-term discharge of the air electrode in the Li-air battery. The discharge and charge voltage behaviors of the battery and the changes to the pH values of the aqueous electrolyte at different current rates were also recorded and are presented in this paper.
The effects of anode orientation (whether an anode is located above or under a cathode) and flow channel design (parallel or serpentine flow channel) on the performance of refuelable zinc-air fuel cells (RZAFC) continuously fed with KOH electrolyte were investigated. The performance test was conducted at different electrolyte flow rates of 2, 4, and 6 ml h−1. A polarization test of the cell was conducted at the initial stage of operation, followed by a long-term current discharge test in potentiostatic mode. The spent zinc powders were characterized by a scanning electron microscope and X-ray diffraction. The experimental results revealed that the anode-bottom orientation in the cell performed much better than the anode-top orientation with 11.4 times higher zinc utilization. The performance reduction of the anode-top orientation cell was caused by the cathode overpotential, due to the flooding of the cathode by water crossover from the anode, which was induced by the gravity force. For the flow channel design effects, there was an optimum electrolyte flow rate, to yield a maximum current discharge capacity, of 4 ml h−1 in this study. At this optimum flow rate, the total charge per gram of zinc delivered from the anode serpentine cell was 1.75 times higher than that from the anode-parallel one.
Hectorite (Na0.3Mg2.7Li0.3Si4O10(OH)2) is a trioctahedral clay mineral with peculiar cation exchange capacity, surface reactivity and adsorption, and easy delamination in water into individual nanolayers, which can then re-assemble in various ways. The aqueous dispersion of hectorite exhibits exclusive rheological and thixotropic properties. The paper reviews recent progress in the synthesis, modification, assembly and applications of hectorite. The present methods for synthesizing hectorite are hydrothermal synthesis, melt synthesis and structure-directed synthesis. Modification of hectorite can be made by ion exchange, intercalation, pillaring and grafting. Layer-by-layer assembly, template assembly and hierarchical assembly have been used to formed a variety of hectorite-containing hybrids and nanocomposites such as films, membranes, capsules and Janus nanoparticles. Hectorite and hectorite-derived materials can be used as adsorbents, catalysts, fluorescent reporters, hydrogels, and biomaterials. Literature survey has indicated that hectorite has been successfully used as rheological and thixotropic materials, and are being developed to be used in battery, fluorescent reporters, drug vehicles and tissue engineering.
The presence of polysulfides in Li–S batteries is highly relevant to the battery performance, but their formation and evolution during battery operation are not well understood. Here the authors design an operando X-ray diffraction experiment to reveal their reaction mechanisms.
Objective Temporal lobe epilepsy (TLE) with hippocampal sclerosis has widespread effects on structural and functional connectivity and often entails cognitive dysfunction. EEG is mandatory to disentangle interactions in epileptic and physiological networks which underlie these cognitive comorbidities. Here, we examined how interictal epileptic discharges (IEDs) affect cognitive performance. Methods Thirty-four patients (right TLE=17, left TLE=17) were examined with 24-hour video-EEG and a battery of neuropsychological tests to measure intelligence quotient and separate frontal and temporal lobe functions. Hippocampal segmentation of high-resolution T1-weighted imaging was performed with FreeSurfer. Partial correlations were used to compare the number and distribution of clinical interictal spikes and sharp waves with data from imagery and psychological tests. Results The number of IEDs was negatively correlated with executive functions, including verbal fluency and intelligence quotient (IQ). Interictal epileptic discharge affected cognitive function in patients with left and right TLE differentially, with verbal fluency strongly related to temporofrontal spiking. In contrast, IEDs had no clear effects on memory functions after corrections with partial correlations for age, age at disease onset, disease duration, and hippocampal volume. Conclusion In patients with TLE of long duration, IED occurrence was strongly related to cognitive deficits, most pronounced for frontal lobe function. These data suggest that IEDs reflect dysfunctional brain circuitry and may serve as an independent biomarker for cognitive comorbidity.
Novel graphitic material containing chromium oxide (Cr2O3) nanoribbons is obtained by carbonizing a mixture of polyfurfuryl alcohol and MIL–101(Cr) at 900°C. Morphological, structural, and chemical analysis of the product is carried out with HR–TEM, SEM, XPS, XRD, and BET surface area. The maximum BET surface area recorded for the nanocomposite is 438m2 g−1. The nanocomposite exhibits a specific capacitance as high as 300Fg−1 at 2mVs−1 and 291Fg−1 at 0.25Ag−1, and presents 95.5% long–term cycling stability over 3000 cycles. The pseudo-capacitive role of Cr2O3 nanoribbons is found to be important towards total capacitance of nanocomposite material.
The multi-element doped alpha nickel hydroxide has been prepared by supersonic co-precipitation method. Three kinds of samples A, B and C are prepared by chemically coprecipitating Ni/Al, Ni/Al/Mn and Ni/Al/Mn/Yb, respectively. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), Particle size distribution (PSD) measurement, X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) are used to characterize the physical properties of the synthesized α-Ni(OH)2 samples, such as chemical composition, morphology, structural stability of the crystal. The results show that all samples are nano-sized materials and the interlayer spacing becomes larger and the structural stability becomes better with the increase of doped elements and doped ratio. The prepared alpha nickel hydroxide samples are added into micro-sized beta nickel hydroxide to form biphase electrode materials for Ni-MH battery. The electrochemical characterization of the biphase electrodes, including cyclic voltammetry (CV) and charge/discharge test, are also performed. The results demonstrate that the biphase electrode with sample C exhibits better electrochemical reversibility and cyclic stability, higher charge efficient and discharge potential, larger proton diffusion coefficient (5.81 × 10−12 cm2 s−1) and discharge capacity (309.0 mAh g−1). Hence, it indicates that all doped elements can produce the synergic effect and further improve the electrochemical properties of the alpha nickel hydroxide.
An extensive set of accelerated aging tests has been carried out employing a Li-ion high energy 18650 system (2.05 Ah), negative electrode: carbon, positive electrode: Li(NiMnCo)O2). It is manufactured by Sanyo, labeled UR18650E, and is a commercial off-the-shelf product. The tests comprise both calendar life tests at different ambient temperatures and constant cell voltages and cycle life tests operating the cells within several voltage ranges and levels using standard test profiles. In total, 73 cells have been tested. The calendar life test matrix especially investigates the influence of SOC on aging in detail, whereas the cycle life matrix focuses on a detailed analysis of the influence of cycle depth. The study shows significant impact of the staging behavior of the carbon electrode on cycle life. Furthermore a strong influence of the carbon potential on calendar aging has been detected. Observed relations between aging and the different influence factors as well as possible degradation mechanisms are discussed. Analysis of C/4 discharge voltage curves suggests that cycle aging results in different aging processes and changes in material properties compared to calendar aging. Cycling, especially with cycles crossing transitions between voltage plateaus of the carbon electrode seems to destroy the carbon structure.
Silicon nanowires grown on a stainless steel current collector were evaluated as Li ion battery anodes in an ionic liquid consisting of butyl-trimethyl ammonium bis(trifluoromethylsulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide. The electrodes showed good performance in the ionic liquid electrolyte with a stable discharge capacity of ∼2000mAhg−1 and coulombic efficiency of 97% after 50 cycles. However, the large internal stresses caused by the volumetric expansion of the Si during lithiation limits the long-term cycle life of the battery in both ionic and organic electrolytes due in-part to the repeated disruption and reformation of the solid electrolyte interface layer on the Si. In contrast, when the same Si nanowire electrode was cycled at relatively shallow discharges, similar to those of carbon anodes, 320mAhg−1, the battery showed better performance with cycle life greater than 650 cycles and coulombic efficiency close to 100% in the ionic liquid electrolyte. Cycling at 1000mAhg−1 showed lifetimes in excess of 200 cycles in an organic electrolyte without cell degradation. The effect of Si doping, and amount of electrolyte in contact with the anode on the battery capacity and cycle life are also presented.
Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is generated when the wind turbines operate at rated capacity. Two representative models of typical remote Canadian communities were created using HOMER, an NREL micro-power simulator to model how a generic energy storage system could help improve the economics of a high-penetration wind–diesel system. Key variables that affect the optimum system are average annual wind speed, cost of diesel fuel, installed cost of storage and a storage systems overall efficiency. At an avoided cost of diesel fuel of 0.30$Cdn/kWh and current installed costs, wind generators are suitable in remote Canadian communities only when an average annual wind speed of at least 6.0m/s is present. Wind energy storage systems become viable to consider when average annual wind speeds approach 7.0m/s, if the installed cost of the storage system is less than 1000$Cdn/kW and it is capable of achieving at least a 75% overall energy conversion efficiency. In such cases, energy storage system can enable an additional 50% of electricity from wind turbines to be delivered.