batterydata/paper-abstracts huggingface dataset:
To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO2 (PMMA-ZrO2) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5 wt % PMMA-ZrO2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10−3 S cm−1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5 wt % PMMA-ZrO2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery.
In order to improve the energy density and power density of supercapacitors, the main concepts of this study are to exploit advantages of three different materials: high energy density of ruthenium oxides (RuO2), high power density of mesoporous carbon CMK-3, and high conductivity of carbon nanotubes (CNTs) to form a composite electrode. The crystallization and dispersion of RuO2, the effects of RuO2 mass fraction, and CMK-3/CNTs on energy/power densities are discussed. Microstructures of all the specimens are characterized by scanning electron microscopy (SEM), inductively coupled plasma-mass spectrometry (ICP-MS), transmission electron microscopy (TEM), N2 adsorption/desorption isotherm and X-ray diffraction (XRD) measurements. Furthermore, the specific capacitance and the ideal density of energy and power are derived from cyclic voltammetry (CV) method. In short, the combination of RuO2, CNT, and CMK-3 lead to enhanced the specific capacitance of 1102F/g, energy density of 0.15Wh/g and power density of 237W/g, which are 4 times and 3 times greater than those of CMK-3, respectively. The results provide effective routes to enhance the capacitance.
In this work the thermoanalytical methods used for the characterization of nanomaterials and nanocomposites are presented. They include thermogravimetry coupled with infrared spectroscopy (TG-FTIR), mass spectrometry (TG-MS) and gas chromathography (TG-GC/MS) which are used to ascertain the influence of nanoparticles on the thermal stability and degradation mechanism of polymer nanocomposites. Other hyphenated techniques - pyrolysis coupled with gas chromatography and/or mass spectrometry (Py-GC, Py-GC/MS), as well as a relatively new technique based on a combination of scanning thermal microscopy and localized thermal analysis known as micro-thermal analysis, can provide valuable data concerning preparation, characterization and decomposition behavior of a wide range of nanomaterials and nanocomposites. Thermoanalytical methods help to determine the thermal properties of nanoparticles and to understand the influence of nanomaterials on polymer phase transitions, thermally induced chemical reactions, as well as thermal transport properties in advanced polymer composites.
Operational and financial optimization of a renewable energy-based stand-alone electricity micro-grid is described. Due to the large problem size in time-series models, we construct the model using mixed integer linear programming (MILP). As the constraints required in this model generally have modest complexity, we were able to perform piece-wise linearization on any non-linear variable relationship. Additionally, controls have also be applied on the demand side. Here, a two stage MILP model has been developed to minimize the overall levelized electricity cost for a micro-grid containing a photovoltaic power source, wind turbine, diesel generator, and an energy storage system. The model aimed to converge on a balance of decision accuracy and computational efficiency. Model outputs were capable of defining both the optimal system sizing and scheduling for each system component, with additional demand management control levers on the loss of power supply probability and load deferring allowance. We believe that this model is one of the first to explore the possibilities of the influences of potential demand management strategies in overall system cost reduction, while presenting a relatively efficient first-pass component sizing for stand-alone micro-grids.
Ti2Nb10O29 is an advanced anode material for lithium-ion batteries due to its large specific capacity and high safety. However, its poor electronic/ionic conductivity significantly limits its rate capability. To tackle this issue, a Cr3+–Nb5+ co-doping is employed, and a series of Cr x Ti2–2x Nb10+x O29 compounds are prepared. The co-doping does not change the Wadsley–Roth shear structure but increases the unit-cell volume and decreases the particle size. Due to the increased unit-cell volumes, the co-doped samples show increased Li+-ion diffusion coefficients. Experimental data and first-principle calculations reveal significantly increased electronic conductivities arising from the formation of impurity bands after the co-doping. The improvements of the electronic/ionic conductivities and the smaller particle sizes in the co-doped samples significantly contribute to improving their electrochemical properties. During the first cycle at 0.1 C, the optimized Cr0.6Ti0.8Nb10.6O29 sample delivers a large reversible capacity of 322 mAh g−1 with a large first-cycle Coulombic efficiency of 94.7%. At 10 C, it retains a large capacity of 206 mAh g−1, while that of Ti2Nb10O29 is only 80 mAh g−1. Furthermore, Cr0.6Ti0.8Nb10.6O29 shows high cyclic stability as demonstrated in over 500 cycles at 10 C with tiny capacity loss of only 0.01% per cycle.
LiFePO4 samples with preferred facets on the ac plane were prepared by the solvothermal method with or without well-dispersed amphiphilic carbonaceous material (ACM). The effects of ACM on the particle morphology, crystal orientation and electrochemical reactivity of the prepared LiFePO4 nanoparticles were investigated in detail. ACM serves a dual purpose. One purpose is facilitating the plate-like morphologies of LiFePO4 nanoparticles parallel to the b Pnma axis by decreasing the surface energy of (010) facets of newly created LiFePO4 nuclei. The other purpose is suppressing crystal growth along the [010] direction by adhering onto the (010) surface of LiFePO4 nanoplates. Furthermore, ACM coating was performed and optimized using a carbon coating precursor. The electrochemical properties of the prepared LiFePO4 particles were characterized by cyclic voltammetry (CV) and galvanostatic charge–discharge cycling tests. After the optimized coating of ACM, the ACM-intervened LiFePO4 composite was observed to deliver discharge capacities of 151.3 mAh g−1 at 1C and 132.2 mAh g−1 at 10C. Even after 1000 cycles at a high rate of 10C, the LiFePO4 cathode could maintain 80% of its initial capacity.
This paper presents a comprehensive review and assessment of the latest research and advancement of electric vehicles (EVs) interaction with smart grid portraying the future electric power system model. The concept goal of the smart grid along with the future deployment of the EVs puts forward various challenges in terms of electric grid infrastructure, communication and control. Following an intensive review on advanced smart metering and communication infrastructures, the strategy for integrating the EVs into the electric grid is presented. Various EV smart charging technologies are also extensively examined with the perspective of their potential, impacts and limitations under the vehicle-to-grid (V2G) phenomenon. Moreover, the high penetration of renewable energy sources (wind and photovoltaic solar) is soaring up into the power system. However, their intermittent power output poses different challenges on the planning, operation and control of the power system networks. On the other hand, the deployment of EVs in the energy market can compensate for the fluctuations of the electric grid. In this context, a literature review on the integration of the renewable energy and the latest feasible solution using EVs with the insight of the promising research gap to be covered up are investigated. Furthermore, the feasibility of the smart V2G system is thoroughly discussed. In this paper, the EVs interactions with the smart grid as the future energy system model are extensively discussed and research gap is revealed for the possible solutions.
Lithium–sulfur batteries (LSBs) are promising alternative energy storage devices to the commercial lithium-ion batteries. However, the LSBs have several limitations including the low electronic conductivity of sulfur (5 × 10−30 S cm−1), associated lithium polysulfides (PSs), and their migration from the cathode to the anode. In this study, a separator coated with a Ketjen black (KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm−2 to mitigate the PS migration. A minimum specific capacity (C s) loss of 0.06% was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm−2. Furthermore, an initial areal capacity up to 6.70 mA h cm−2 was obtained at a sulfur loading of 7.88 mg cm−2. The low C s loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group (SO3 −) of Nafion, respectively, which could physically and chemically trap the PSs.
This review critically examines the literature from 1985 to 1999 on applicant perceptions of selection procedures. We organize our review around several key questions: What perceptions have been studied? What are determinants of perceptions? What are the consequences or outcomes associated with perceptions applicants hold? What theoretical frameworks are most useful in examining these perceptions? For each of these questions, we provide suggestions for key research directions. We conclude with a discussion of the practical implications of this line of research for those who design and administer selection processes.
This report describes the preparation, characterization, and coin cell prototype testing of new Li[Fe1/3Ni1/3Co1/3]PO4 high voltage olivine cathodes for lithium secondary batteries (LFNCPs) obtained by treating the precursors with Cu and Cu+C sources. The morphology, structure, interactions, and electrochemical properties of the obtained materials are extensively studied in order to elucidate the interplay in LFNCPs between graphite (C) and copper(II) carbonate (Cu) addition to the precursors and structural flexibility, relaxations, and electrochemical performance of obtained materials. In particular, the investigated LFNCPs cathodes are obtained by treating the reaction precursors with graphite nanoparticles and/or copper(II) carbonate. It is found that copper does not behave like a vicariant metal ion within the olivine structure of the cathodes, instead it forms segregated CuO nanoparticles which improve the charge-transfer kinetics during the charge/discharge processes of the cathode material. The graphite additive in precursors is found to decompose during the synthesis, resulting in an improved elasticity of the 3D structure of the olivine backbone. This increased structural flexibility facilitates the percolation of lithium ions along the 1D channels of the materials during the charge/discharge processes. Coin cell prototypes assembled with the proposed cathode materials show good specific capacities (>100mAhg−1), good specific energies (455mWhg−1), and a high working potential (>4.0V).
We examined script representation in 26 patients with Alzheimer's disease (AD) compared to 31 healthy elderly subjects (HE). Participants were asked to sort cards describing actions belonging to eight scripts according to the script to which they belonged and according to their order of execution. Each script included actions which were low in centrality and distinctiveness (non-central actions and non-distinctive actions – NCA & NDA), and which were high in centrality (central actions – CA), distinctiveness (distinctive actions – DA), centrality and distinctiveness (central actions and distinctive action – CA & DA). These actions were presented in three conditions. In the first condition (scripts with headers – SH), the 43 actions belonging to three different scripts were given with each script header written on separate cards. The second condition (scripts without headers – SwH) used 46 actions belonging to three other scripts, but no script header was provided. In the third condition (scripts with distractor header – SDH), the 28 actions belonging to two other scripts were given with each script header and a distractor header written on separate cards. The results showed that performance of subjects with AD was significantly lower in all conditions. Overall, AD patients made significantly more sequencing errors than HE subjects. AD patients also committed significantly more sorting errors than HE subjects for all types of actions (NCA & NDA, CA, DA, CA & DA). These data are consistent with the view that AD produces impairment of both the syntactic and semantic dimensions of script representation.
This paper presents the photovoltaic technology, the world’s market trends in the past few years and its future map till 2050. The paper shows the PV market development in the world in terms of cumulative installed PV capacity from 2000 to 2013 as actual PV installation in all the world in terms of total installed PV capacity (135GW), annual installed PV capacity (37GW) and PV electricity energy generated in each year. According to the forecast of global PV generation, China is expected to be the largest producer of PV electricity soon after 2020. By contrast, the United States’ share is expected to remain at about 15% starting 2020 onwards, while Europe’s share is expected to decrease constantly from 2015 to 2045. The paper also shows that almost all of the energy consumption in Egypt was met by oil and natural gas at 41% and 46% respectively. The remainder was supplied by coal and renewable energy sources. The current demand forecast expects a six percent demand growth per year over the next seven years. Egyptian Electric Holding Company is currently implementing new generation projects to produce 7000MW over the next few years. For the purpose of designing and sizing PV systems the paper presents the five relevant economic methods of financial analysis that are often used for making building investment decisions. These methods are payback analysis, net benefit analysis, saving-to-investment ratio, adjusted internal rate of return and life-cycle cost. In the same manner, the paper presents two case studies of the financial assessment analyzing PV systems in Egypt. The first case is relates to the on-grid PV 10MW power plant for different sites, while the second paper describes the finance analysis of a standalone off-grid PV system generating electricity to feed a residential house in rural area of Egypt.
Four kinds of anthracites from different regions were investigated as anodic materials of Li ion secondary battery by varying their calcination temperatures. Hon-gye anthracite calcined at 1000–1150°C showed a high reversible capacity at low potential region of 0–0.12V, which is typical with hard carbon. The highest capacity of 370mAh/g was obtained with the Hon-gye among anthracites calcined at 1100°C. The graphitization started with the anthracite above 1600°C to provide capacity at ca. 0.2V which reflects the intercalation of graphitic carbon. The anthracite calcined at 1000–1150°C was indicated to carry the largest d 002 and smallest Lc(002). And TEM observation showed micropores among the graphite clusters. The large capacity of the anthracite as hard carbon is ascribed to its many micropores among the smallest graphite units which can accommodate highly reduced lithium ions.
Background Characterizing neuropsychological (NP) functioning of individuals at clinical high risk (CHR) for psychosis may be useful for prediction of psychosis and understanding functional outcome. The degree to which NP impairments are associated with general cognitive ability and/or later emergence of full psychosis in CHR samples requires study with well-matched controls. Methods We assessed NP functioning across eight cognitive domains in a sample of 73 CHR youth, 13 of whom developed psychotic-level symptoms after baseline assessment, and 34 healthy comparison (HC) subjects. Groups were matched on age, sex, ethnicity, handedness, subject and parent grade attainment, and median family income, and were comparable on WRAT-3 Reading, an estimate of premorbid IQ. Profile analysis was used to examine group differences and the role of IQ in profile shape. Results The CHR sample demonstrated a significant difference in overall magnitude of NP impairment but only a small and nearly significant difference in profile shape, primarily due to a large impairment in olfactory identification. Individuals who subsequently developed psychotic-level symptoms demonstrated large impairments in verbal IQ, verbal memory and olfactory identification comparable in magnitude to first episode samples. Conclusions CHR status may be associated with moderate generalized cognitive impairments marked by some degree of selective impairment in olfaction and verbal memory. Impairments were greatest in those who later developed psychotic symptoms. Future study of olfaction in CHR samples may enhance early detection and specification of neurodevelopmental mechanisms of risk.
Integration of solar photovoltaics of 25 kWp capacity has been achieved in an existing building of the cafeteria on the campus of the Indian Institute of Technology, Delhi by creating a solar roof covering an area of about 250 m2. The photovoltaic array is inclined at an angle of 15° from the horizontal and faces due south. The architectural challenge of the project lies in achieving integration of the system with the existing habitat, to be aesthetically appealing, structurally sound and enclosing a space which is proposed for commercial usage and exhibition purposes. The interior space of the solar photovoltaic roof has to be protected from the summer heat and for the same a composite system of natural and mechanised ventilation and cooling systems is proposed. The design of the solar photovoltaic roof has been conceived, the architectural and interior designs finalised. A model has been prepared for a perspective view and clarity of form.
As a member of the liquid electrolyte family, ionic liquids (ILs) possess distinctive chemical and electrochemical stability, offering a pathway to realize supercapacitors (SCs) with both outstanding energy density and high safety. Nevertheless, the rapid development of IL based SCs is largely limited due to the high viscosity and poor ionic conductivity of ILs. One feasible solution, albeit challenging, is implementing ion regulation for IL electrolytes because of the highly adjustable nature of anions and cations. This paper provides an overview of the recent progress in ion regulation for IL-based SCs. We describe the energy storage mechanisms and ion regulation methods of IL electrolytes in electrical double-layer capacitors, with special emphasis on the effects of ion regulation to the electrochemical performance of electrode materials and devices. Moreover, we also discuss challenges in regulating IL-based electrolytes for SCs from personal perspectives, and give future possible directions for constructing superior IL-based electrolytes for the next generation of SCs.
Activated carbon (AC) with high surface area (1901 m2 g−1) is synthesized from low cost bio-waste orange (Citrus sinensis) peel for vanadium redox flow battery (VRB). The composition, structure and electrochemical properties of orange peel derived AC (OP-AC) are characterized by elemental analyzer, field emission-scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy. CV results show that OP-AC coated bipolar plate demonstrates improved electro-catalytic activity in both positive and negative side redox couples than the pristine bipolar plate electrode and this is ascribed to the high surface area of OP-AC which provides effective electrode area and better contact between the porous electrode and bipolar plate. Consequently, the performance of VRB in a static cell shows higher energy efficiency for OP-AC electrode than the pristine electrode at all current densities tested. The results suggest the OP-AC to be a promising electrode for VRB applications and can be incorporated into making conducting plastics electrode to lower the VRB cell stack weight and cost.
This study assessed neurocognitive and neurologic outcomes of children with neonatal and childhood strokes. Twenty-one children with neonatal (mean age, 6.86 years) and 10 children with childhood (mean age, 8.21 years) strokes, identified via the Estonian Pediatric Stroke Database (1995-2006), participated. A developmental neuropsychologic assessment was used for neurocognitive outcomes, and the Paediatric Stroke Outcome Measure for neurologic outcomes. Neuromotor impairment was evident in 62% of children with neonatal strokes, and in 70% of children with childhood strokes. Compared with control subjects, children with strokes exhibited worse attention, language, memory, and sensorimotor functions. The sensorimotor domain comprised the most impaired neurocognitive area, whereas executive functions remained intact in both stroke groups. A well-preserved executive function may account for the normal range of intelligence in children with strokes. More severe impairment in neurocognitive skills was evident after neonatal strokes, and the visuospatial domain was more impaired than in children from the childhood group. Prognoses were worse after left hemisphere strokes associated with epilepsy. Our results on emerging neurocognitive deficits in several areas underline the importance of neuropsychologic testing and the follow-up of children with pediatric strokes.
Two conductive polymers were evaluated to be the active materials in a sensor device for the detection of beta radiation. This was accomplished by characterizing the changes in conductivity of electrically conducting polymer films caused by exposure to tritium gas for varying lengths of time. The behavior of these materials when exposed to gamma radiation was also studied to gain further insight into the mechanism of conductivity degradation by ionizing radiation. Two types of conductive polymer, polyaniline (PANi) and poly(3,4-ethylenedioxythiophene) (PEDOT), were chosen as candidate materials for their widespread commercial use. The change of surface resistance (conductivity) of PANi and PEDOT films when exposed to gamma radiation in both air and deuterium environments was evaluated as well as tritium exposures in 104 and 105 Pa gas. Raman and absorbance spectra of gamma irradiated samples were obtained to determine the mechanism of conductivity degradation in both polymers. Post-irradiation gas analysis of the samples contained in deuterium revealed very little (or no) hydrogen in the containment vessel, indicating that hydrogen–deuterium isotopic exchange was not responsible for the decrease in surface conductivity due to gamma exposure. The effects of irradiation-induced oxidation were also studied for both conductive polymers during gamma irradiation. It was concluded that chain scission via free radical formation and chain cross-linking are most likely the two dominant mechanisms for conductivity change and not de-protonation of the polymer.