batterydata/paper-abstracts huggingface dataset:
In this study, graphene was added to LiFePO4 via a hydrothermal method to improve the lithium-ion-diffusion ability of LiFePO4. The influence of graphene addition on LiFePO4 was studied by X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, cycling test, and AC impedance analysis. The addition of graphene to LiFePO4 resulted in the formation of a LiFePO4–graphene composite; XRD observations revealed the composite to have a single phase with an olivine-type structure. Furthermore, LiFePO4 particles in the composite were stacked on the graphene sheet surface, thereby enabling the composite to form an effective conducting network and facilitate the penetration of the surface of active materials by an electrolyte. The lithium-ion-diffusion ability of the LiFePO4–graphene composite was greater than that of pure LiFePO4. Of a number of materials studied [namely, pure LiFePO4, LiFePO4–graphene (1 %), LiFePO4–graphene (5 %), and LiFePO4–graphene (8 %)], LiFePO4–graphene (5 %) delivered the best electrochemical performance with a lithium-ion-diffusion coefficient of 8.18 × 10−12 cm2 s−1 and the highest specific discharge capacity of 149 mAh g−1 at 0.17 C; in contrast, the corresponding values for pure LiFePO4 were 3.01 × 10−12 cm2 s−1 and 109 mAh g−1, respectively. Further, LiFePO4–graphene (5 %) showed a very high specific discharge capacity of 170 mAh g−1 at 0.1 C, which is equal to the theoretical capacity of LiFePO4.
Analogical reasoning is the cognitive skill of drawing relationships between representations, often between prior knowledge and new representations, that allows for bootstrapping cognitive and language development. Analogical reasoning proficiency develops substantially during childhood, although the mechanisms underlying this development have been debated, with developing cognitive resources as one proposed mechanism. We explored the role of executive function (EF) in supporting children’s analogical reasoning development, with the goal of determining whether predicted aspects of EF were related to analogical development at the level of individual differences. We assessed 5- to 11-year-old children’s working memory, inhibitory control, and cognitive flexibility using measures from the National Institutes of Health Toolbox Cognition battery. Individual differences in children’s working memory best predicted performance on an analogical mapping task, even when controlling for age, suggesting a fundamental interrelationship between analogical reasoning and working memory development. These findings underscore the need to consider cognitive capacities in comprehensive theories of children’s reasoning development.
A multistep sintering schedule is developed to synthesize Li7La3Zr2O12 (LLZO) doped with 0.2 mol% Al3+. The effect of sintering steps on phase, relative density and ionic conductivity of Al-doped LLZO has been evaluated using powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), 27Al magic spinning nuclear magnetic resonance (NMR) spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that by holding the sample at 900 °C for 6 h, the mixture of tetragonal and cubic garnet phases are obtained; by continuously holding at 1100 °C for 6 h, the tetragonal phase completely transforms into cubic phase; by holding at 1200 °C, the relative density increases without decomposition of the cubic phase. The Al-LLZO pellets after multistep sintering exhibit cubic phase, relative density of 94.25% and ionic conductivity of 4.5 × 10−4 S cm−1 at room temperature. Based on the observation, a sintering model is proposed and discussed.
Spherical porous LiFePO4/C (LFP/C) composite materials were prepared by employing a solid-state (SS) method and a spray dry (SP) method. The surface modification was conducted on the spherical LFP/C composite using 1–5wt.%Li4Ti5O12 (LTO) to improve the rate capability and the cycle stability properties at low temperature (0°C) and elevated temperature (55°C). The characteristic properties were examined through X-ray diffraction, micro-Raman spectroscopy, scanning electron microscopy, an AC impedance method, and galvanostatic charge–discharge method. The characteristic properties of the SS-LFP/C, SP-LFP/C, and LTO-coated SP-LPF/C composites were studied and compared. The 3wt.%LTO-coated SP-LFP/C composite exhibited the most favorable performance among the samples. It exhibited discharge capacities of 150, 141, 131, 110, 103, and 84mAhg− 1, at rates of 0.2C, 0.5C, 1C, 3C, 5C, and 10C, respectively. It was also found that the 3wt.%LTO-coated SP-LFP/C composite shows the best cycling stability performance at elevated temperature of 55°C. The LTO-coated SP-LFP/C composite was demonstrated to be suitable for high-temperature and high-power application in lithium-ion batteries.
A comprehensive review of the state-of-the-art macroscopic modeling studies on lithium oxygen (Li O2) and lithium air (Li–air) batteries has been presented. The Li O2 battery is a promising device for energy storage in portable electronics and electric vehicles due to its high specific energy. A number of technical challenges need to be addressed in order to bring this technology from laboratory concept to real products. The multi-scale, multi-physics phenomena in a Li O2 battery encompasses a wide range of scientific disciplines, including electrochemistry, heat and mass transfer, and material science. Modeling study provides a powerful tool to understand the charge-species transport phenomena inside a battery that cannot be captured by experimentation. It offers insight to optimize battery design and fabrication. Macroscopic models that treat battery components as continuous media will be the focus of this review while pore-scale sub-models that are integrated with macroscopic models to describe structural changes of battery components (mainly electrodes) will be presented and compared as well. Recent developments and opportunities for future improvement and advancement are also discussed. Finally, a detailed summary of property data relevant to Li O2 batteries is provided because of their critical role in modeling studies.
In sensor networks, a compromised node can either generate fabricated reports with false votes or inject false votes into real reports, which causes severe damage such as false alarms, energy drain and information loss. An interleaved hop-by-hop authentication (IHA) scheme addresses the former attack by detecting and filtering false reports in a deterministic and hop-by-hop fashion. Unfortunately, in IHA, all en-route nodes must join to verify reports while only a few are necessary to the authentication procedure. In this paper, we propose a fuzzy-based interleaved multi-hop authentication scheme based on IHA. In our scheme, the fuzzy logic system only selects some nodes for verification based on the network characteristics. Moreover, we apply a voting method and a hash-based key assignment mechanism to improve network security. Through performance evaluation, the proposed scheme is found to save up to 13% of the energy consumption and to provide more network protection compared to IHA.
X-ray diffraction experiments and accelerating rate calorimetry on the reaction of fully charged Li[Co1−z Al z ]O2 (0≤ z ≤0.15) in PC (propylene carbonate) solvents have been performed. The XRD results show the Li[Co1−z Al z ]O2 samples are in single phase and lie in the range of 0≤ z ≤0.15. The lattice constants vary smoothly with z for these samples, this suggests that the co-precipitation method can produce materials with a uniform cation distribution when the aluminum content is between 0 and 0.15. The impact of Al substitution on the thermal stability of LiCoO2 samples was studied by comparing accelerating rate calorimetry with non substituted sample. The ARC results show the substitution of Al improves the thermal stability of the samples. According to thermal kinetics research, the improved thermal stability is caused by a dramatic reduction in the frequency factor or a change in the reaction model for the reaction.
Rational design and fabrication of nonprecious metallic multifunctional catalysts with superior performance are crucial for energy-related electrochemical devices. Herein, we report the synthesis and electrochemical properties of a sandwich-like Co@Co3O4 embedded into Fe, N, S co-doped reduced graphene oxide (Co@Co3O4/FeNS-RGO) nanocomposite catalyst. The designed Co@Co3O4/FeNS-RGO catalyst is synthesized by pyrolysis of one-pot solvothermal method-induced nano-zeolitic imidazolate framework (ZIF)/graphene oxide nanocomposite using dimethylsulfoxide as both the solvent and sulfur source. The synthesized catalyst exhibits the outstanding electrocatalytic activity in basic media for oxygen reduction reaction and oxygen evolution reactions, which outperforms the commercial Pt/C and IrO2 catalysts, respectively. In addition, the synthesized catalyst also shows a promising electrocatalytic activity towards hydrogen evolution reaction. The performance of the thus-assembled zinc-battery and the overall water-splitting device reveals that the synthesized Co@Co3O4/FeNS-RGO can be practically applied in energy-related electrochemical devices with great activity and stability.
New R–Mg–Ni (R: rare earths) superlattice alloys with higher-capacity and higher-durability than the conventional Mm–Ni alloys with CaCu5 structure have been developed. The oxidation resistibility of the superlattice alloys has been improved by optimizing the alloy composition by such as substituting aluminum for nickel and optimizing the magnesium content in order to prolong the battery life. High-capacity nickel-metal hydride batteries for the retail market, the Ni-MH2500/900 series (AA size type 2500mAh, AAA size type 900mAh), have been developed and commercialized by using an improved superlattice alloy for negative electrode material.
With less than 6 mm of rain from November through February every year, the central regions of Nigeria are in acute need of safe and consistent water supplies for drinking and other domestic or agricultural uses. Borehole supplies are capable of meeting a significant proportion of water needs, but ongoing fuel costs to power a generator and pump add a heavy burden to already disadvantaged communities. In this study, a techno-economic analysis is carried out in order to assess the feasibility of renewable energy sources and technologies to substitute for fossil-fuel powered pumping platforms. The results indicate that there is sufficient solar resource throughout these regions to facilitate relatively cost effective water pumping solutions, as well as a potentially effective wind resource depending on the exact location of the pumping station. Although systems based on these resources have high capital costs compared to petrol or diesel-based platforms, over a 20-year project life, the analysis indicates that ongoing fuel costs for a fossil-fuel-based system greatly outweigh the increased up-front costs of renewable alternatives. In conclusion, the results indicate that if the water demand at a particular site exceeds the capabilities of a hand pump, a renewable energy-powered pumping system is an attractive option, both economically and logistically in comparison to fossil-fuel-powered alternatives.
Reducing the manufacturing time is the trend of precision manufacturing, and the precision of a work-piece is very important for manufacturing industry. High-speed cutting is becoming more widely used and the high-speed spindle is a very important element, whose precision may affect the overall performance of high-speed cutting. Most of the studies on high-speed cutting are focused on the cutting force, the vibration of the spindle and the effects of the spindle's thermal expansion; however, the measurement of the high-speed spindle continues to use the conventional spindle measurement method. As with the measurement of the high-speed spindle, more strict demands are set on the dynamic balance of cutting tools and the bandwidth of the measurement systems when compared with common spindles. The capacitance displacement sensor has been employed for the spindle error test. The precision of the measurement system is limited by the reference (such as a master ball or a master cylinder). Also the capacitance sensor and the reference must be grounded together. This paper presents a simple spindle measurement system using a laser diode and a quadrants sensor, with accuracy up to 1μm, within 300,000rpm for various spindles. The system does not need any reference and it is easy to set up. This system can be applied to measure the spindle errors, the spindle speed and the spindle indexing.
We tested the effect of Al concentration on the performance of lithium-ion cells. One set of cells contained a LiNi0.8Co0.15Al0.05O2 cathode and the other, LiNi0.8Co0.10Al0.10O2. The cells were calendar- and cycle-life tested at several temperatures, with periodic interruptions for reference performance tests that were used to gauge capacity and power fade as a function of time. The C 1/25 capacity fade in the cells displayed t 1/2 dependence. The capacity fade of the 10% Al-doped cells tested at 45°C was similar to that of the 5% Al-doped cells at 25°C. The impedance rise and power fade were also sensitive to the Al concentration. For the one common temperature investigated (i.e., 45°C), the 10% Al-doped cells displayed higher impedance rise and power fade than the 5% Al-doped cells. Additionally, the time dependence of the impedance rise displayed two distinct kinetic regimes; the initial portion depended on t 1/2 and the final, on t. On the other hand, the 10% Al-doped cells depended on t 1/2 only.
Screening to identify individuals with elevated brain amyloid (Aβ+) for clinical trials in Preclinical Alzheimer’s Disease (PAD), such as the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s disease (A4) trial, is slow and costly. The Trial-Ready Cohort in Preclinical/Prodromal Alzheimer’s Disease (TRC-PAD) aims to accelerate and reduce costs of AD trial recruitment by maintaining a web-based registry of potential trial participants, and using predictive algorithms to assess their likelihood of suitability for PAD trials.
To mark the fifth anniversary of Nature Energy, past and present editors share their take on some favourite papers.
The electronic cigarette (e-cigarette), for many considered as a safe alternative to conventional cigarettes, has revolutionised the tobacco industry in the last decades. In e-cigarettes, tobacco combustion is replaced by e-liquid heating, leading some manufacturers to propose that e-cigarettes have less harmful respiratory effects than tobacco consumption. Other innovative features such as the adjustment of nicotine content and the choice of pleasant flavours have won over many users. Nevertheless, the safety of e-cigarette consumption and its potential as a smoking cessation method remain controversial due to limited evidence. Moreover, it has been reported that the heating process itself can lead to the formation of new decomposition compounds of questionable toxicity. Numerous in vivo and in vitro studies have been performed to better understand the impact of these new inhalable compounds on human health. Results of toxicological analyses suggest that e-cigarettes can be safer than conventional cigarettes, although harmful effects from short-term e-cigarette use have been described. Worryingly, the potential long-term effects of e-cigarette consumption have been scarcely investigated. In this review, we take stock of the main findings in this field and their consequences for human health including coronavirus disease 2019 (COVID-19).
Spinel LiMn2O4 powder has been prepared by an auto-ignited combustion of poly(acrylic acid) (PAA)-metal nitrate precursor. The formation route to spinel LiMn2O4 phase from the precursor strongly depends on the mole ratio (MR) of PAA to metal nitrate. The precursors with MR=1.0 and 6.0 directly produced crystalline LiMn2O4 powders by the auto-ignited combustion at very low temperature (200°C), whereas the precursor with MR=3.0 produced Mn3O4, MnO, and carbonate at the auto-ignited combustion stage and formed spinel LiMn2O4 phase after further calcinations at higher temperatures. The obtained LiMn2O4 powders are composed of very fine primary particles (<100nm) but highly agglomerates and have surface area of 14–29m2 g−1.
The goal of this pilot study was to evaluate the effectiveness of a multi-component consultation package in improving teachers’ classroom management skills, particularly among teachers with lower baseline levels of knowledge, skills, and intervention-supportive beliefs. Participants were 58 elementary school teachers (93% female; 50% non-Hispanic White) who received up to eight biweekly consultation sessions focused on general classroom management strategies and implementation of a daily report card intervention with one target student with or at risk of ADHD. Teachers were randomly assigned to either a comparison consultation condition designed to mirror current best practices (Frank & Kratochwill, in: Erchul, Sheridan (eds) Handbook of research in school consultation, Routledge, New York, 2014; Noell & Gansle, in: Erchul, Sheridan (eds) Handbook of research in school consultation, Routledge, New York, 2014) or a multi-component condition designed to simultaneously address teacher knowledge, skills, and beliefs as possible barriers to implementation of classroom interventions. Teachers in both conditions showed significant improvements in labeled praise, appropriate response to student rule violations, and general competence in classroom management. In support of the hypotheses, teachers with lower baseline levels of knowledge, skills, and intervention-supportive beliefs demonstrated more improvement in key outcomes in response to multi-component consultation, as compared to the comparison consultation (Cohen’s d ranged from 0.33 to 1.12). Implications for research and practice in school consultation are discussed.
In this study, nanoarchitectured polyimide (PI) gel polymer electrolyte (GPE)-coated lithium cobalt oxide (LiCoO2) cathode materials are fabricated and their application to high-voltage lithium-ion batteries is explored. Distinctive features of the PI coating layer are the highly-continuous surface coverage with nanometer thickness (∼5nm) and also the facile ion transport via the nanoscale layer. Based on the physicochemical characterization of the PI coating layer, its influence on the cell performance and thermal stability of high-voltage charged LiCoO2 is investigated as a function of charge cut-off voltage (herein, 4.4, 4.5, and 4.6V). The anomalous nanoarchitectured PI coating layer, which behaves as an ion-conductive protection barrier to mitigate the undesired side reactions predominantly occurring onto the charged LiCoO2 surface, plays a viable role in improving the cell performance and alleviating the interfacial exothermic reaction between the delithiated LiCoO2 and liquid electrolyte. Notably, these advantageous effects of the PI-coated LiCoO2 become more pronounced as the charge cut-off voltage is increased, where liquid electrolyte is highly vulnerable to electrochemical decomposition.
This paper presents nitrogen and boron co-doped KOH-activated bamboo-derived carbon as a porous biomass carbon with utility as a supercapacitor electrode material. Owing to the high electrochemical activity promoted by the hierarchical porous structure and further endowed by boron and nitrogen co-doping, electrodes based on the as-obtained material exhibit significantly enhanced specific capacitance and energy density relative to those based on most similar materials. An asymmetric supercapacitor based on this novel carbon material demonstrated satisfactory energy density and electrochemical cycling stability.
Access to electrification in rural areas of East Timor is extremely limited with as few as 5% of rural households connected to electricity. The government of East Timor intends to increase rural access to electricity significantly in the coming decade. The introduction of small PV systems is envisaged for many households in the most remote areas. Several agencies have piloted the introduction of small solar home systems (SHS) and solar lanterns. In the Railaco sub-district of East Timor, some 1000 households have experience of using either SHS and/or solar lanterns and are in a unique position to indicate a preference regarding these forms of PV lighting technology. This paper reports on a survey of 76 households in Railaco investigating experience with PV lighting systems. Results of the survey indicate a strong preference by users for SHS rather than lanterns. The preference for SHS arose from a range of factors including: a perception of better light quality; ability to illuminate the whole house; reduced risk of damage to the PV equipment; and longer duration of nightly operation. The research indicates that where a single PV lighting system is provided, users are likely to prefer SHS to solar lanterns.
Constant miniaturization of electronic devices opens the way to the development of thin film microbatteries (TFB). For this type of devices, the use of an all-solid-state thin film technology has many advantages over conventional lithium cells. These microbatteries are thin, bendable and can be produced with a customizable shape for integration in microelectronic devices. Moreover, without liquid electrolyte, they are safer. With the aim to support the industrial production of these TFBs, adequate tools for understanding the electrochemical behavior of the complete microbattery and the identification of their possible failures that can occur have to be developed. In this context, the Electrochemical Impedance Spectroscopy seems to be a good compromise for cells characterization. Widely used for the characterization of liquid electrolyte-based batteries, this technique has been less applied to all solid state batteries, mainly because of the difficulty to work with a two-electrode system. There has been no comprehensive study deeply explaining the impedance evolution during the entire life of a microbattery. In this paper, physical characterizations of individual active materials and aging experiments have been performed in order to undoubtedly assign each EIS contributions, and to propose a more comprehensive electrical model for this family of commercial all-solid-state microbatteries.
In this paper, a porous silicon (Psi) surface modification process, including the incorporating of pure and CuO mixed SnO2 within a Psi layer, was investigated. A Psi layer with a pore-like structure prepared via laser-assisted etching process with a laser illumination intensity of (40) mW/cm2 was employed as a substrate for materialization SnO2/CuO/Psi nanocomposites for gas sensing application. Pure SnO2 and SnO2:CuO nanoparticles were synthesized via a chemical spray pyrolysis process on the Psi surface at 350 °C. The materialization of SnO2:CuO/Psi nanocomposites were recognized through Field-Emission Scanning Electron Microscopy, X-ray Diffraction, Atomic Force Microscopy, and Energy-dispersive X-ray Analysis. The results displayed that the morphological properties of SnO2:CuO nanoparticles were definitely controlled by varying the CuO contents. Different shapes (nearly cubic shape and spherical shape) with various sizes of SnO2 and SnO2:CuO within the Psi surface were achieved by increasing the CuO content. SnO2:CuO/Psi nanocomposites, plans, grain size, average surface roughness, homogeneity and specific surface area of SnO2:CuO nanoparticles were considerably influenced by CuO content. The lower grain size and higher average surface roughness and specific surface area were attained when the percentage of CuO was about 30% within the structure of 70% SnO2:30% CuO, and the performance of the NH3 gas sensor revealed a short response time with a high sensitivity of (88%).