batterydata/paper-abstracts huggingface dataset:
A flexible graphene/multiwalled carbon nanotube (GN/MWCNT) film has been fabricated by flow-directed assembly from a complex dispersion of graphite oxide (GO) and pristine MWCNTs followed by the use of gas-based hydrazine to reduce the GO into GN sheets. The GN/MWCNT (16wt.% MWCNTs) film characterized by Fourier transformation infrared spectra, X-ray diffraction and scanning electron microscope has a layered structure with MWCNTs uniformly sandwiched between the GN sheets. The MWCNTs in the obtained composite film not only efficiently increase the basal spacing but also bridge the defects for electron transfer between GN sheets, increasing electrolyte/electrode contact area and facilitating transportation of electrolyte ion and electron into the inner region of electrode. Electrochemical data demonstrate that the GN/MWCNT film possesses a specific capacitance of 265Fg−1 at 0.1Ag−1 and a good rate capability (49% capacity retention at 50Ag−1), and displays an excellent specific capacitance retention of 97% after 2000 continuous charge/discharge cycles. The results of electrochemical measurements indicate that the freestanding GN/MWCNT film has a potential application in flexible energy storage devices.
Redox electrolytes have proven to be extremely important in determining the performance of dye-sensitized solar cells (DSCs). The design and understanding of the redox couple, especially iodide free systems, has become a recent focus of DSC electrolyte research. In this perspective article, advances in the conception and performance of various redox shuttles including molecular hole transport materials are reviewed with respect to their structure and the charge transfer dynamics at the counter electrode. In particular the discussion will focus on the trends that enable iodide-free redox couples to be the most effective and their feasibility to be used in DSCs in combination with new and innovative sensitizers and counter electrode materials.
3, 3’-sulfonyldipropionitrile (SDPN) is structurally different from previously reported compounds and was studied as a film-forming additive for the LiMn2O4 cathode at elevated temperature. The retention capacity of the LiMn2O4/Li cell with the electrolyte (1.0M LiPF6–EC/DMC/EMC) containing 0.5wt% SDPN cycled at 55°C and increased significantly from 56.7% to 70.3% after 200 cycles. The SDPN is more easily oxidized than the solvents, and may take part in the formation of the interface layeon the cathode surface. The results of electrochemical impedance spectroscopy (EIS) and nuclear magnetic resonance spectroscopy (NMR) show that the solid electrolyte interphase (SEI) is gradually formed during cycling. The X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) data demonstrate that a thinner SEI with less inorganic degradation products can be formed on the surface of the LiMn2O4 cathode due to SDPN.
α-Fe2O3/reduced graphene oxide (rGO) nanocomposites were successfully synthesized within 15 min through a facile, environmentally friendly microwave hydrothermal method. From field emission scanning electron microscopy and transmission electron microscopy, it can be determined that the α-Fe2O3 nanoparticles, around 50 nm in diameter, are uniformly anchored on the graphene nanosheets. The as-obtained α-Fe2O3/rGO nanocomposites were applied as anode materials in sodium-ion batteries, which could deliver capacity of ∼310 mAh g−1 after 150 cycles at 100 mA g−1.
Layered-layered oxides of the type xLi2MnO3·(1− x)LiMO2 (M=Mn, Ni, Co) have been postulated to contain Li2MnO3 domains which, upon electrochemical activation, give rise to a characteristic potential plateau at 4.5V vs. Li+/Li. To improve our understanding of the complex reaction mechanisms at play, we applied in situ Raman microscopy to investigate the constituent Li2MnO3. Li2MnO3 synthesised via a two-step solid-state reaction was characterised by scanning electron microscopy and X-ray diffraction. Preliminary electrochemical tests and ex situ Raman microscopy showed the need for elevated temperatures to achieve activation. For the first time, in situ Raman microscopy (at 50°C) confirmed the activation of Li2MnO3. The main signal at 615cm−1 shifted to higher wavenumbers upon charging. After reaching 4.4V vs. Li+/Li, this shift grew significantly, which is in good agreement with the onset of the potential plateau in both Li2MnO3 and xLi2MnO3·(1− x)LiMO2, and is assigned to the partial formation of a spinel-like phase.
Abstract In this heuristic article, we show the usefulness of arguments at the level of scaling laws through examples taken from classic and practical problems. In the textbooks of elasticity and hydrodynamics, exactly solvable problems are very limited, and even for such problems, derivations of solutions require lengthy calculations. However, if we give up deriving numerical coefficients for the solutions, most of them can be obtained by simple dimensional analysis, i.e., arguments at the level of scaling laws. This is a powerful tool to cope with practical problems. We start our discussion from classic problems and proceed to two examples relevant to biomedical applications: microfluidic devices and elasticity tuning of sheet materials.
Lithium-ion capacitors, as a hybrid electrochemical energy storage device, realize high specific energy and power density within one device, thus attracting extensive attention. Here, hierarchically porous Li3VO4/C nanocomposite is prepared by a solvo-thermal reaction, followed with a post-annealing process. This composite has macropores at the center and mesopores in the wall, thus effectively promoting electrolyte penetration and structure stability upon cycling simultaneously. Compared to mesoporous Li3VO4, the enhanced rate capability and specific capacity of hierarchically porous Li3VO4/C indicate the synergistic effect of mesopores and macropores. Inspired by these results, this composite is coupled with mesoporous carbon (CMK-3) for lithium-ion capacitors, generating a specific energy density of 105 Wh kg−1 at a power density of 188 W kg−1. Even if the power density increases to 9.3 kW kg−1, the energy density still remains 62 Wh kg−1. All these results demonstrate the promising potential of hierarchically porous Li3VO4 in lithium ion capacitors.
Layered double hydroxides (LDHs), a class of anionic clays consisting of brucite-like host layers and interlayer anions, have been widely investigated in the last decade due to their promising applications in many areas such as catalysis, ion separation and adsorption. Owing to the highly tunable composition and uniform distribution of metal cations in the brucite-like layers, as well as the facile exchangeability of intercalated anions, LDHs can be modified and functionalized to form various nanostructures/composites through versatile processes such as anion intercalation and exfoliation, decoration of nanoparticles, self-assembly with other two-dimensional (2D) materials, and controlled growth on conductive supports (e.g., nanowire arrays, nanotubes, 3D foams). In this article, we briefly review the recent advances on both the LDH nanostructures and functionalized composites toward the applications in energy conversion, especially for water oxidation.
A three-dimensional (3D) hierarchical porous graphene macrostructure coupled with uniformly distributed α-Fe2O3 nano-particles (denoted Fe-PGM) was designed as a sulfur host in a lithium-sulfur battery, and was prepared by a hydrothermal method. In this hybrid structure, the α-Fe2O3 nano-particles are proved to not only strongly interact with the polysulfides, but more importantly, chemically promote their transformation to insoluble species during the charge/discharge process, working as chemical barriers for the shuttling of the lithium polysulfides (LiPSs). Therefore, together with 3D hierarchical porous structure facilitating fast electron/ion transfer, Fe-PGM as a sulfur host in a cathode contributes to a high rate performance (565 mAh g−1 at a high rate of 5C relative to 1571 mAh g−1 at 0.3C) as well as long cyclic stability (an ultralow capacity fading rate of 0.049% per cycle over 1000 cycles at the high current rate of 5C).
In this study, fast ionic conductor Li0.33La0.557TiO3 (LLTO) nanowires with high ionic conductivity were prepared through electrospinning and subsequent high temperature calcination. It was filled in the poly(ethylene oxide) (PEO) matrix as a filler and the novel solid PEO/LiTFSI/LLTO-nanowires polymer composite electrolytes were prepared via solution casting method with low cost. The results showed that the addition of LLTO nanowires could effectively improve the ionic conductivity, electrochemical stability window, transference number, and compatibility with lithium metal of polymer composite electrolytes. The maximum ionic conductivities of composite electrolytes filled with 5 wt% LLTO nanowires at room temperature and 60 °C were 5.53 × 10−5 S cm−1 and 3.63 × 10−4 S cm−1, respectively. Its electrochemical stability window was up to 4.75 V. The LiFePO4/Li solid-state lithium-ion battery assembled with the novel polymer composite electrolytes had good cycling stability. At current rate of 0.5 C, the discharge specific capacity remained about 123 mAh g−1 after 100 cycles at 60 °C.
Recent progress in genomics has contributed to the identification of a large number of autism spectrum disorder (ASD) risk genes, many of which encode synaptic proteins. Our understanding of ASDs has advanced rapidly, partly owing to the development of numerous animal models. Extensive characterizations using a variety of behavioral batteries that analyze social behaviors have shown that a subset of engineered mice that model mutations in genes encoding Shanks, a family of excitatory postsynaptic scaffolding proteins, exhibit autism-like behaviors. Although these behavioral assays have been useful in identifying deficits in simple social behaviors, alterations in complex social behaviors remain largely untested.
Eggs are an important source of food due to its favorable effects on human health derived from the protein, fats, minerals, vitamins and bioactive components. We studied the effects of source of eggs in the retail market on fatty acids, lipid profiles and antioxidant status in eggs.
Jones KJ, Cochran TM, Jensen LE, Roehrs TG, Volkman KG, Goldman AJ. A cross-sectional assessment of stroke rehabilitation in Nebraska hospitals. Objective To assess the structure and process of stroke rehabilitation in Nebraska hospitals. Design Cross-sectional mail survey using the Dillman tailored-design method of administration. Setting Hospitals in Nebraska. Participants Approximately 77% of the 84 Nebraska hospitals that provide stroke rehabilitation are critical access hospitals (CAHs) that are limited to 25 beds. Our study sample of hospitals (N=53) included the 19 hospitals licensed for 47 to 689 beds (non-CAHs) and a stratified random sample of 34 of the 65 CAHs. Interventions Not applicable. Main Outcome Measures Self-reported stroke rehabilitation team structure and processes, purposes of and barriers to the use of evidence-based standardized assessments, specific assessments used, and access to specialized stroke rehabilitation services and community resources. Results Thirty-six (68%) of the 53 hospitals responded to the survey. Approximately 61% of the hospitals used an organized team to provide stroke rehabilitation; 8% of the hospitals—all non-CAHs—had a team dedicated to stroke rehabilitation. After adjusting for hospital size, having an organized team was significantly associated with the use of standardized assessments to improve communication, measure progress and outcomes, evaluate effectiveness of practice, and compare patient outcomes across conditions. Access to specialized stroke rehabilitation professionals and services was significantly greater in non-CAHs. Conclusions Hospital size and the presence of a team are determinants of the structure and process of stroke rehabilitation in Nebraska hospitals. Further research is needed to determine (1) whether team structure is a determinant of stroke rehabilitation outcomes across the continuum of care settings, (2) the needs of rural stroke survivors, and (3) whether technology can facilitate the use of stroke rehabilitation standardized assessments by rural health care professionals.
Waste consumer batteries are recycled using different routes based on hydrometallurgical and pyrometallurgical processes. Two hydrometallurgical and two pyrometallurgical treatment scenarios are compared starting from an average composition of Belgian waste batteries. The environmental performance is compared using life cycle analysis (LCA). The recycling rate is studied through mass balance calculation. Each treatment scenario results in a specific recycling rate. The environmental impact and benefits also vary between the treatment options. There is no such thing as a typical hydrometallurgical or pyrometallurgical treatment. When applying a hydrometallurgical treatment scenario, the focus lies on zinc and iron recycling. When allowing manganese recycling, the energy demand of the hydrometallurgical process increases considerably. Both pyrometallurgical options recycle zinc, iron and manganese. According to the LCA, none of the treatment scenarios performs generally better or worse than the others. Each option has specific advantages and disadvantages. The Batteries Directive 2006/66/EC sets out a recycling rate of 50% for consumer waste batteries. Based on metal recycling alone, the mass balances show that the target is difficult to obtain.
Br-doping Li4Ti5O12 (Li4Ti5O11.7Br0.3) is fabricated by conventional solid state method and shows enhanced cycling performance compared with pristine Li4Ti5O12. After thermal nitridation for 90 min in NH3, the Li4Ti5O11.7Br0.3 electrode exhibits better rate capability and excellent cycling performance. It delivers a reversible capacity of 138 mAh g−1 and 104 mAh g−1 after 100 cycles at 10C and 20C, respectively, which is approximately four and seven times higher than those of pristine Li4Ti5O12 at the same current rates. This work indicates the feasibility of improving cycling performance and rate capabilities of Li4Ti5O12 through controlling both surface termination and bulk doping procedures.
Although growing evidence supports the efficacy of social cognitive training interventions for schizophrenia, nearly all studies to date have been conducted in Westernized countries. In the current study, we translated and adapted an existing social cognitive skills training (SCST) program into Arabic and conducted a preliminary efficacy evaluation in schizophrenia outpatients in Egypt. Twenty-two patients were randomized to 16 sessions of group-based SCST and 20 were randomized to a format- and time-matched illness management training control condition. Pre- and post-intervention assessments included a primary social cognition outcome measure that assessed four branches of emotional intelligence and a battery of neurocognitive tests. The SCST group demonstrated significant treatment effects on total emotional intelligence scores (F =24.31, p<.001), as well as the sub-areas of Identifying Emotions (F =11.77, p<.001) and Managing Emotions (F =23.27, p<.001), compared with those in the control condition. There were no treatment benefits for neurocognition for either condition, and both interventions were well-tolerated by patients. These initial results demonstrate the feasibility of implementing social cognitive interventions in different cultural settings with relatively minor modifications. The findings are encouraging regarding further efforts to maximize the benefits of social cognitive interventions internationally.
The effect of carbonization temperature on the electrical resistivity and physical properties of solid (ash) wood, plywood, and particleboard carbonized in a vacuum furnace under a gas flow of nitrogen (200ml/min) between 400 and 1100°C was investigated. The electrical resistivity, dimension shrinkage and weight loss of the carbonized specimens were extensively investigated. The electrical resistivity of specimens significantly decreased with increasing carbonization temperature. The rates of the volumetric shrinkage and weight loss of the specimens significantly increased with increasing the temperature. At the carbonization temperature of 1100°C, the particleboard had the highest electrical conductivity property, followed by the plywood and solid wood, respectively. The electrical resistivities of wood, plywood, and particleboard carbonized at 1100°C were less than about 1ohm-cm, thereby making them suitable for use as an electrode in a fuel cell, battery or electrolyzer.
CoMn2O4 nanofibers with hollow structures are successfully prepared by the electrospinning technique. These hollow nanofibers are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TG) and Brunauer-Emmett-Teller (BET) analyzer. The temperature-dependent experiments are also carried out to monitor the evolution process of CoMn2O4 hollow nanofibers (HNs), and a possible formation mechanism is introduced reasonably based on the investigations. When evaluated as an electrode material for lithium-ion batteries, the results of electrochemical test show that these unique CoMn2O4 HNs exhibit admirable lithium storage performances with high specific capacity and excellent rate capability. The hollow and continuous one dimensional (1D) nanostructures of the CoMn2O4 HNs make a prominent contribution to the excellent electrochemical performance.
Ocean wave energy is one of the most abundant and widely distributed renewable energy resources, but it has not been extensively used so far due to the cost and efficiency issues of typical wave energy converters (WECs) based on electromagnetic generators. In recent years, the rapid development of triboelectric nanogenerator (TENG) technology provides a highly promising solution for cost-effectively harnessing the low-frequency ocean wave energy. In this work, we report a novel WEC design based on the multi-grating triboelectric nanogenerator (MG-TENG) model. It is shown that the designed MG-TENG is able to deliver over 140 V open-circuit voltage and 60 μA rectified short-circuit current, respectively, which is enough to power over 60 commercial LEDs. What's more, its average charging current achieves 12.3 μA, which is better than most reported TENG models. Particularly, instead of sparse pulse signals generated from those TENG models in vertical contact-separation mode, the MG-TENG works in a freestanding triboelectric-layer mode which is able to provide more continuous and smooth power outputs, thus is more suitable for the low-frequency wave energy harvesting. Moreover, the MG-TENG based wave energy converter is designed, fabricated and tested in a wave tank under different wave conditions. It is observed that the instantaneous power output reaches 54 μW and the instantaneous maximum power output density arrives at 4.2 mW/m2 under the 8 cm and 0.5 Hz wave condition, exhibiting strong power output capability. It can be expected that array installation of MG-TENG WECs is a potential solution for the power supply problem in marine environment.
This paper examines the application of electrochemical impedance spectroscopy (EIS) for analysis of the electrochemical properties of industrial lubricants and focuses on establishing a relationship between lubricant chemical composition and EIS data. Presented data demonstrate a need to rely on several EIS output parameters collected over wide frequency, electrochemical dc potential, temperature and electrode geometry ranges in order to assess complex processes and decomposition pathways occurring both at the interface and in the bulk solution. Impedance characteristics for three frequency regions were studied—bulk solution-influenced high frequency response, medium frequency parameters representing adsorption of surface active lubricant additives at the electrode interface, and low frequency characteristics related to diffusion and charge transfer processes. The modeling and analysis of the EIS data as a combination of changes in bulk, adsorption, diffusion and charge transfer resistances, capacitances and constant phase element (CPE) parameters allow studying the conditions of a lubricant. The electrochemical structure of a typical industrial lubricant through the use of an equivalent circuit (EC) model is presented. The model can be used for analysis of the impedance results as a reflection of chemical composition and changes in the system.
Efficient electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is the most critical factor to influence the performance of lithium–air batteries. We present La0.8Sr0.2MnO3 (LSM) perovskite nanorods as high active electrocatalyst fabricated via a soft template method for lithium–air batteries. The as–prepared LSM nanorods are microporous with numerous defects and large surface area (20.6 m2 g−1), beneficial to the ORR and OER in the discharge and charge processes, respectively. Lithium–air batteries based on the microporous LSM nanorods electrocatalysts show enhanced electrochemical performances, including high first discharge specific capacity (6890 mAh g−1 (electrode) at 200 mA g−1), low overpotential, good rate capability (up to 400 mA g−1), and cycle stability (only 1.1% voltage loss after 30 circles of specific capacity limit of 1000 mAh g−1 tested at 200 mA g−1). The improved performance might be due to the synergistic effect of the unique microporous and one–dimensional structure and numerous defects of the prepared LSM catalyst.
We verified the origin of water-infiltration-induced electricity generation by an ionovoltaic effect, specifically, ion–surface interaction induced potential asymmetry in porous structures. When 20 μl of water (NaCl, 0.1 M) infiltrates into a porous CuO nanowire film, electrical power of ∼0.45 V and ∼0.23 μA is produced for 40 minutes. Moreover, a method of proportionally amplifying electricity is presented, and the practicability is shown by turning on an LED with infiltration of eight seawater droplets.
A derivation of the fundamental impedance of a Lithium-Ion battery electrode is given, exemplarily conducted for a solid thin-film electrode. The focus of this derivation is not on developing a model which is able to reproduce the exact behaviour of a given electrode, but rather on deriving its fundamental characteristics from few and intuitive assumptions in a simple and transparent way. It is thus shown, that the fundamental impedance of a solid thin-film electrode consists of an RC-element for charge-transfer, a Finite-Length Warburg element for diffusion in the electrolyte and a Finite-Space Warburg element for diffusion in the solid-state. The use of a Finite-Length Warburg element with a serially connected capacitor for modelling diffusion in the solid-state is thus indicated to be physically questionable. In addition, the theoretically expected behaviour of charge-transfer and solid-state diffusion on the degree of lithiation (State-of-Charge) is derived and discussed.