batterydata/paper-abstracts huggingface dataset:
During discharge in aprotic Li-O2 batteries, lithium peroxide (Li2O2) can be formed by a surface- or solution-mediated route. In the surface-mediated process, a Li2O2 film is formed electrochemically on the cathode surface, leading to low capacity and rate capability. In contrast, in high donor or acceptor number electrolyte systems, Li2O2 toroids are formed by solution-mediated growth through a disproportionation reaction, resulting in high capacity and rate capability. However, during charging, high donor or acceptor number solvents cause poor rechargeability because of the high crystallinity of Li2O2 toroids and byproduct formation. Therefore, controlling the size of Li2O2 in a solution-mediated discharge process is the key to the development of Li-O2 batteries with high capacity and good rechargeability. We demonstrate the application of Pd3Co nanoparticles to enhance the rechargeability of a Li-O2 cell in a solution-mediated process. Scanning electron microscopy and X-ray diffraction studies indicate that the Li2O2 particles formed during discharge are small and the decomposition of the reaction products is reversible. A cell fabricated with Pd3Co nanoparticles exhibits a lower overpotential than the one without the nanoparticles. The additive may provide nucleation sites for Li2O2 particles, leading to enhanced rechargeability and appropriate capacity in a solution-mediated process for Li-O2 batteries.
Due to limited flexibility of engine operation, it is uneasy to improve the fuel economy of parallel hybrid electric vehicles (HEVs) with a single electric machine (SEM) from control perspective only. However, from design perspective, it is likely to devise multiple operating modes on a powertrain system to achieve better fuel economy. Therefore, in this paper, a velocity coupling HEV system with a SEM has been proposed, which has eleven modes, including an electric vehicle (EV) mode, three regenerative braking modes, an engine-start mode, an electrically variable transmission (EVT) mode, a parallel HEV mode, an engine-only mode, and three charging modes. Dynamic Programming (DP), as a global optimization algorithm, is leveraged to minimize the fuel consumption of this system. For comparison purposes, the P1 and P2 HEV systems are also examined by DP using the same vehicular parameters. Comparative results indicate that the P2 HEV saves about 6.68% fuel consumption over the P1 HEV, while more improvement can be observed from the proposed velocity coupling HEV, with 13.82% fuel consumption reduction over the P1 HEV.
The chemical composition of waste of small electrical and electronic equipment (s-WEEE), a rapidly growing waste stream, was determined for selected metals (Cu, Sb, Hg etc.) and non-metals (Cl, Br, P) and PCBs. During a 3-day experiment, all output products and the s-WEEE input mass flows in a WEEE recycling plant were measured. Only output products were sampled and analyzed. Material balances were established, applying substance flow analysis (SFA). Transfer coefficients for the selected substances were also determined. The results demonstrate the capability of SFA to determine the composition of the highly heterogeneous WEEE for most substances with rather low uncertainty (2σ ⩽±30%). The results confirm the growing importance of s-WEEE regarding secondary resource metals and potential toxic substances. Nowadays, the thirty times smaller s-WEEE turns over larger flows for many substances, compared to municipal solid waste. Transfer coefficient results serve to evaluate the separation efficiency of the recycling process and confirm – with the exception of PCB and Hg – the limitation of hand-sorting and mechanical processing to separate pollutants (Cd, Pb, etc.) out of reusable fractions. Regularly applied SFA would serve to assess the efficacy of legislative, organizational and technical measures on the WEEE.
The behavior under irradiation of neat propylene carbonate (PC), a co-solvent usually used in Li-ion batteries (LIB), and also of Li salt solutions is investigated. The decomposition of neat PC is studied using radiolysis in the pulse and steady state regime and is assigned to the ultrafast formation, in the reducing channel, of the radical anion PC − by electron attachment, followed by the ring cleavage, leading to CO. In the oxidative channel, the PC(H) radical is formed, generating CO2. The CO2 and CO yields are both close to the ionization yield of PC. The CO2 and CO productions in LiClO4, LiBF4 and LiN(CF3)2(SO2)2 solutions are similar as in neat PC. In contrast, in LiPF6/PC a strong impact on PC degradation is measured with a doubling of the CO2 yield due to the high reactivity of the electron towards PF6 − observed in the picosecond range. A small number of oxide phosphine molecules are detected among the various products of the irradiated solutions, suggesting that most of them, observed in carbonate mixtures used in LIBs, arise from linear rather than from cyclical molecules. The similarity between the degradation by radiolysis or electrolysis highlights the interest of radiolysis as an accelerated aging method.
Using TG–FT-IR coupling method, direct evidences of the decomposition process of lithium hexafluorophosphate had been obtained. Studies showed that LiPF6 is stable under normal temperature when the content of water is very low. When heated, LiPF6 would react with the trace water in the air. HF and OPF3 would be released in the same time which could be detected from the FT-IR spectra collected in situ. The peak temperature of the decomposition of LiPF6 varied from 192.93°C (average heating rate 2.0°Cmin−1) to 223.83°C (average heating rate 20.0°Cmin−1). Based on the on-line FT-IR spectra, the characteristic absorption bands of PF6 − in the decomposed substances were detected for the first time which might come from the reaction of trace HF with PF5.
Based on a porous carbon electrode, capacitive deionization (CDI) is a promising desalination technology in which ions are harvested and stored in an electrical double layer. However, the ion removal capacity of CDI systems is not sufficient for desalting high-concentration saline water. Here, we report a novel desalination technique referred to as “hybrid capacitive deionization (HCDI)”, which combines CDI with a battery system. HCDI consists of a sodium manganese oxide (Na4Mn9O18) electrode, an anion exchange membrane, and a porous carbon electrode. In this system, sodium ions are captured by the chemical reaction in the Na4Mn9O18 electrode, whereas chloride ions are adsorbed on the surface of the activated carbon electrode during the desalination process. HCDI exhibited more than double the ion removal sorption capacity (31.2 mg g−1) than a typical CDI system (13.5 mg g−1). Moreover, it was found that the system has a rapid ion removal rate and excellent stability in an aqueous sodium chloride solution. These results thus suggest that the HCDI system could be a feasible method for desalting a highly concentrated sodium chloride solution in capacitive techniques.
Organic-inorganic hybrid solid electrolytes composed of Li+-conducting lithium aluminum germanium phosphate (LAGP), poly(ethylene oxide) (PEO), lithium perchlorate and succinonitrile (SN) were prepared in the form of flexible thin film, and their electrochemical properties were investigated. The hybrid solid electrolytes showed high ionic conductivities ranging from 3.0×10−5 to 1.1×10−4 Scm−1 at room temperature and exhibited good electrochemical stability. A solid-state Li/LiFePO4 cell assembled with hybrid solid electrolyte composed of 70wt.% LAGP, 21wt.% PEO-LiClO4 and 9wt.% SN delivered a high discharge capacity and exhibited good capacity retention at ambient temperature. Good cycling performance of the cell resulted from the high ionic conductivity of the solid electrolyte and its good interfacial contacts with electrodes.
The first stage in the implant of a total knee arthroplasty with computer-assisted surgery is to fasten the emitters to the femur and the tibia. These trackers must be hard-fixed to the bone. The objectives of our study are to evaluate the technical problems and complications of these tracker-pins, the necessary time to fix them to the bone and the possible advantages of a new femoral-fixed tracker-pin.
Synthesis of the spinel lithium titanate Li4Ti5O12 by an alkoxide-free sol–gel method is described. This method yields highly pure and crystalline Li4Ti5O12 samples at relatively low temperature (850°C) and via short thermal treatment (2h). 6Li magic angle spinning nuclear magnetic resonance (MAS NMR) measurements on these samples were carried out at high magnetic field (21.1T) and over a wide temperature range (295–680K). The temperature dependence of the chemical shifts and integral intensities of the three 6Li resonances demonstrates the migration of lithium ions from the tetrahedral 8a to the octahedral 16c sites and the progressive phase transition from a spinel to a defective NaCl-type structure. This defective structure has an increased number of vacancies at the 8a site, which facilitate lithium diffusion through 16c →8a →16c pathways, hence providing an explanation for the reported increase in conductivity at high temperatures. Molecular dynamics simulations of the spinel oxides Li4+x Ti5O12, with 0≤ x ≤3, were also performed with a potential shell model in the temperature range 300–700K. The simulations support the conclusions drawn from the NMR measurements and show a significant timescale separation between lithium diffusion through 8a and 16c sites and that out of the 16d sites.
Purpose Most school vision screenings test only visual acuity. There is a need for a valid, easily administered test that screens for a wider variety of learning-related vision problems. Visual Efficiency RAting (VERA) is a software program designed for schools to detect both routine vision problems and visual skill problems. The purpose of this study was to compare the VERA visual skills screening with the optometric assessment of binocular, accommodative, and ocular motor skills. Methods One hundred fifty-four children from grades 3 through 5 were evaluated using the VERA visual skills screening, a clinical battery of visual skills testing, the Convergence Insufficiency Symptom Survey, and 2 reading tests. Results The sensitivity of VERA in detecting visual skills problems was 45%, and the specificity was 83%. Sensitivity increased to 64% and specificity to 100% in smaller groups of children when overlays of symptoms, classroom behaviors, and reading skills were included. Conclusions VERA has fairly good sensitivity and very good specificity in detecting visual skills problems. Given that the majority of visual skill deficits currently go undetected, VERA can be considered a reasonably effective method of in-school visual skills screening.
A series of Al-substituted spinel powders LiNi0.5−x Al2x Mn1.5−x O4 (0 ≤ 2x ≤ 1.0) have been prepared and the effects of Al concentration on the structural, electrochemical and thermal properties are investigated. The XRD patterns show that impurity arises when 2x ≥ 0.6. The FTIR and Raman spectra indicate that the introduction of Al in the LiNi0.5Mn1.5O4 increases the disordering degree of Ni/Mn ions, changing the spinel structure from P4332 to F d 3 ¯ m . Cyclic voltammetry tests show that the voltage step between Ni2+/Ni3+ and Ni3+/Ni4+ have a sudden leap at 2x = 0.075, responding to the structural difference of the spinels. The Al concentration is optimized in the range of 0.05 ≤ 2x ≤ 0.1, in which the cyclic stability and rate capability of the LiNi0.5−x Al2x Mn1.5−x O4 spinels are significantly improved. At room temperature the LiNi0.45Al0.10Mn1.45O4 presents the best cycle performance with the capacity retention of 95.4% after 500 cycles at 1C rate, and the best rate capability with the discharge capacity of 119 mAh g−1 at 10C rate, which is about 93.7% of its capacity at 0.5C. The thermal properties of the spinels have been tested by C80 calorimeter and the results show that introduction of Al in LiNi0.5Mn1.5O4 can effectively suppress the exothermic reaction below 225 °C, thus improve the safety of the high voltage cathode material.
It is extremely challenging to reclaim materials from spent lithium ion batteries that have more complicated chemistries than lead-acid batteries. In this work, a new approach is proposed to reclaim the graphitic anode materials from spent lithium ion batteries in electric vehicles, which involves a facile water treatment. With compositional and structural characterizations, it is found that the spent graphite anode still retains integrated graphitic structure with an inclusion of electrolyte decomposition products that are mainly responsible for the failure of a battery. Water treatment removes most of these impurities, opens Li+ transport channel and restores the graphite to be electrochemically active. After 100 cycles, the reclaimed graphite retains a capacity of 345 mAh g−1, which is comparable to the 347 mAh g−1 for commercial graphite. The approach we proposed requires neither harmful chemicals nor high temperature operation, providing a green and viable solution to the ever increasing threat caused by the vast mass of spent lithium ion batteries generated by electric vehicle industry.
Safety is a major issue in the development of lithium-ion batteries. Now, a thermoresponsive polymer composite embedded into electrodes is shown to rapidly shut down batteries at overheating but quickly resume function at normal conditions.
Deficits in confrontation naming ability can occur after epilepsy surgery in the left temporal lobe. This study addresses the functional relationship between postoperative object naming and semantic and phonological speech processing in patients with epilepsy. Fifty-eight consecutive patients with temporal lobe epilepsy from our epilepsy surgery program (24 patients with left temporal lobe epilepsy, 34 patients with right temporal lobe epilepsy) were investigated using the Boston Naming Test and comprehensive semantic and phonological speech testing. Language dominance was evaluated in all patients with the preoperative intracarotid sodium amytal test. Naming decline was observed exclusively in patients with left temporal lobe epilepsy. Regression analysis with semantic processing and phonological input/output processing as independent variables, and naming change in the Boston Naming Test (preoperative–postoperative score) as a dependent variable, revealed a significant association between postoperative naming decline and impaired semantic functions. Accordingly, patients exhibited deficits in the category-related differentiation of objects. It is hypothesized that naming deficits arise from the functional specialization of the left temporal lobe for semantic interpretation of visual input.
Novel high performance active electrode materials for green energy-storage systems attract great interest in the past decades. Here, for the first time, 3D mesoporous flower-like CuCo2S4/CuCo2O4 heterostructure with compatible nanoscale interfaces and tunable chemical composition is designed and prepared. Because of the unique architecture and components, the electrode exhibits large electrochemical surface area, enhanced conductivity, short ion diffusion path, and rapid electron and ion transport rate, resulting in its outstanding electrochemical properties of specific capacity (599.9C g−1), excellent cycling stability and high rate capability. An asymmetric supercapacitor device based on these unique nanoflowers as cathode and graphene aerogel as anode delivers substantial energy density (33.2 W h kg−1), power density (13.3 kW kg−1), and high long-term stability (73% capacitance retention after 10000 cycles). These results imply great potential application in high-performance supercapacitors.
In the USA, gun deaths occur at a rate that is 25 times higher than that of other developed countries (Grinshteyn and Hemenway in Am J Med 129(3):266–273, 2016. https://doi.org/10.1016/j.amjmed.2015.10.025). However, legislation targeted toward regulating firearms often fails to pass into law. While surprising to many observers, this policy response follows an established pattern in American politics: despite public support for tighter gun laws, the gun rights lobby often successfully suppresses gun reform due to their greater monetary resources, political savvy, and access to grassroots support than advocates of gun control (Bruce-Briggs in The Public interes 45:37, 1976; Goss in Disarmed: the missing movement for gun control in America, Princeton University Press, Princeton, 2006). However, laws that restrict domestic abusers from owning firearms have diverged from this pattern. This study identifies an element of advocates’ political strategy that increased the likelihood of policy change: the prominence of domestic violence prevention advocates and “strategic absence” of larger gun control groups in the policy debate. The insights generated by this study shed light on broader questions about advocacy strategy, the policy-making process, and the modern politics of firearms.
A photoinduced electron transfer system involving the tris(2,2′-bipyridyl)ruthenium complex, methylviologen and trithiocyanuric acid was constructed and used to induce a disulfide polymer on the electrode photochemically. Since the resulting polymer on the electrode can be depolymerized electrochemically, this system can be used for rewritable image formation. Furthermore, it was found that positively charged molecules were immobilized on the electrode by electrostatic bonding with the deprotonated mercapto groups on the disulfide polymer. These results indicate that a marked patterning of positively charged functional molecules on the disulfide polymer is possible using this photopolymerization system.
Polymeric gel containing alkylphosphate has been examined as nonflammable gel electrolyte for LiMn2O4 positive electrode of lithium-ion battery (LIB). The gel was composed of a polymer matrix of poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) and a liquid component consisting of ternary solvent of trimethyl phosphate (TMP) mixed with ethylene carbonate (EC) and diethyl carbonate (DEC) that dissolves lithium salt (LiPF6 or LiBF4). The gel composition of 0.8M (moldm−3) LiX (X=PF6 and BF4) dissolved in EC+DEC+TMP (55:25:20) with PVdF-HFP showed excellent nonflammable characteristics and high ionic conductivity of ca. 3.1mScm−1 at room temperature (20°C). The charge–discharge cycling test of LiMn2O4 positive electrode gave good reversibility with high capacitance in the gel electrolyte. With respect to the electrolyte salt, LiBF4 was better than LiPF6 due to its thermal stability during the gel preparation.
Around 20% of world population lives without electricity access, most of them are concentrated in Sub-Saharan rural areas. Traditional approaches to electrify rural areas imply capital intensive infrastructures and large investments, while DC microgrids, based on renewable sources and storage systems, can be easily implementable and lead to cost effective solutions. The use of super efficient appliances can dramatically reduce the households electricity consumption, leading to smaller and cheaper systems. In this study an analysis of the use of efficient DC appliances is performed starting by essential energy services. Solar home system design optimization can be achieved by the evaluation of irradiation variation and the load requirements, finding the most cost-effective solution. Rural electrification can have a major impact to drastically improve the quality of life of millions of people through the sustainable use of solar energy.
Growing evidence suggests that decreased functional connectivity in cortical networks precedes clinical stages of Alzheimer’s disease (AD), although our knowledge about cerebral and biological correlates of this phenomenon is limited. To shed light on this issue, we have investigated whether resting-state oscillatory connectivity patterns in healthy older (HO) and amnestic mild cognitive impairment (aMCI) subjects are related to anatomical grey matter (GM) and functional (2-[18F]fluoro-2-deoxy-
Nowadays, due to the increased price of fossil fuels and their decreasing resources on the one hand, and the importance of environmental pollution on the other, use of electric vehicles (EVs) has been increased. Charging of EVs has imposed new loads on power systems. These new and major loads along with the deregulation of power systems, which introduces new uncertainties to grid, have caused new challenges for the frequency control and stability of power systems. Use of EVs as moving batteries in deregulated power systems is one of the ways for dealing with this problem. In this method, charging EVs is controlled and, when necessary, EV battery is discharged in grid. This concept is called vehicle to grid (V2G), which was employed in this study for the control of the frequency of a smart deregulated grid. For this purpose, an optimized fuzzy controller was used to control EVs. Using the proposed method, charging or discharging of batteries was carried out with respect to grid frequency and battery state of charge. To investigate the proposed approach, a 35-bus system as a deregulated system was assumed. Then, this system was converted into a three area system in order for the frequency analysis. Simulations were performed in MATLAB/SIMULINK environment and the results illustrated the good performance of the proposed method in terms of frequency control of deregulated system. Moreover effect of proposed method on under frequency load shedding was verified. It was illustrated that by using of proposed method under frequency load shedding is postponed.
The thermal degradation of α and β PbO2 and its relationship to capacity loss was studied using galvanostatic discharge and voltamperometry. The results clearly demonstrate the dramatic effect of the thermal treatment on the capacity of the PAM. The variation of proton diffusion with temperature was determined for both α- and β-PbO2. The two forms of PbO2 exhibit different behaviour with regard to water loss.
Economic and environmental concerns over fossil fuels encourage the development of photovoltaic (PV) energy systems. Due to the intermittent nature of solar energy, energy storage is needed in a stand-alone PV system for the purpose of ensuring continuous power flow. Three stand-alone photovoltaic power systems using different energy storage technologies are studied in this paper. Key components including PV modules, fuel cells, electrolyzers, compressors, hydrogen tanks and batteries are modeled in a clear way so as to facilitate the evaluation of the power systems. Based on energy storage technology, a method of ascertaining minimal system configuration is designed to perform the sizing optimization and reveal the correlations between the system cost and the system efficiency. The three hybrid power systems, i.e., photovoltaic/battery (PV/Battery) system, photovoltaic/fuel cell (PV/FC) system, and photovoltaic/fuel cell/battery (PV/FC/Battery) system, are optimized, analyzed and compared. The obtained results indicate that maximizing the system efficiency while minimizing system cost is a multi-objective optimization problem. As a trade-off solution to the problem, the proposed PV/FC/Battery hybrid system is found to be the configuration with lower cost, higher efficiency and less PV modules as compared with either single storage system.
Electrodeposition of metals from non-aqueous solutions is reviewed. Attention is paid mainly to surface morphology of deposits and their adhesion. The major reasons for carrying out electrodeposition in non-aqueous electrolytes (such as conventional organic solvents, ionic liquids and molten salts) are the water and air stability and the wide electrochemical window of these media. The following metals have been electrodeposited and investigated for the last 15 years: aluminum, zinc, silver, palladium, tantalum, zirconium, gadolinium, plutonium, nickel, cobalt, and other alloys.