batterydata/paper-abstracts huggingface dataset:
The aim of this study is to examine the status of rare earth elements (REE) contained in the chemical compounds that make up the powder of spent fluorescent lamps, with a view of their recovery. The status of REE in the as-received powder, as well as in a few size-class fractions of it, has been established. This way, only those size-class fractions containing high REE concentrations can be considered in a recovery process. The investigation has been carried out using particle-size, chemical, TGA/DTA, XRPD, SEM-EDS and EMPA analyses. The last technique enabled to establish the status of REE within the lattice of the chemical compounds present in the powder. The fineness of the as-received powder and the higher REE concentration in the finest size-classes suggest that physical methods of separation should not be used to separate the REE-containing chemical compounds from each other. Leaching methods seem more suitable with a material of such size.
This study has examined the effect of water on the electrodeposition of copper from a deep eutectic solvent (DES). Initial physiochemical measurements showed that the viscosity and resistivity of the DES decreased with added water in the range 1–15 wt%. This reduction in viscosity resulted in an increase in the mass transfer limiting current, without narrowing the electrochemical window or altering the speciation of the copper chloro-complexes. This shows that metal deposition rates can be increased by water additions. The effect of water on the electrochemical kinetics of the Cu(I) and Cu(II) chloro-complexes was also studied. It was found that the kinetics of the Cu(I)/Cu(0) reaction is largely irreversible, while the Cu(II)/Cu(I) couple was quasi-reversible. The rate constants for Cu(II)/Cu(I) and Cu(I)/Cu(0) reactions were accelerated by water additions, although the transfer coefficients remained unchanged. The effect of increased deposition rates, electrolyte conductivity and reaction kinetics on deposit uniformity was estimated and subsequently verified by experiments. It was found that, although higher deposition rates could be achieved, the thickness of the deposit was non-uniform since the Wagner numbers remained relatively low.
Whether or not a current account deficit sustainable has important implications for policy. If the current account deficits of a nation is sustainable, then it implies that the government should have no incentive to default on its international debt. In this article we examine whether or not the current account deficits for the OECD countries can be characterized by a unit root process with regime switching. The econometric methodology allows us to distinguish periods that are associated with unsustainable outcomes from those in which the intertemporal national long-run budget constraint (LRBC) holds. Among the main results, it is found that it is very likely that the LRBC will not hold for the Australia, the Czech Republic, Finland, Hungary, New Zealand, Portugal or Spain, thus signifying a red signal that the current account deficits observed during the period were probably not on a sustainable path.
The synergistic effects of carboxymethyl cellulose (CMC) and zinc oxide (ZnO) have been investigated as alkaline electrolyte additives for the AA5052 aluminium alloy anode in aluminium-air battery by the hydrogen evolution test, the electrochemical measurements and the surface analysis method. The combination of CMC and ZnO effectively retards the self-corrosion of AA5052 alloy in 4 M NaOH solution. A complex film is formed via the interaction between CMC and Zn2+ ions on the alloy surface. The carboxyl groups adsorbed on the surface of aluminium make the protective film more stable. The cathodic reaction process is mainly suppressed significantly. AA5052 alloy electrode has a good discharge performance in the applied electrolyte containing the composite CMC/ZnO additives.
Co3O4 & LiCoO2 complex cladding layer with nutty-cake structure effectively improves high rate and storage properties of high nickel material LiNi0.8Co0.15Al0.05O2 (NCA), using a simple one-step wet-coating process, and the degradation of NCA is successfully restrained. The structure and morphology of samples are demonstrated by X-ray diffraction (XRD), scanning electron microscope (SEM), and field-emission high resolution transmission electron microscope (FEHRTEM). The elemental composition and distribution are determinate by energy dispersive spectrometer (EDS). In comparison with pristine NCA, 0.25wt.% Co3O4-modified NCA has a better electrochemical performance with more capacity of approximate 30mAhg−1 at 1C after 150 cycles. At 5C and 10C, it also exhibits better capacity retentions and higher capacities. After exposed to the air for 100 days, 0.25wt. % Co3O4-modified NCA still shows better electrochemical performance than pristine NCA stored at the same condition. The improved comprehensive performance of Co3O4 & LiCoO2 coated NCA is related with the facile coating method in which Co3O4 is formed and the lithium impurity on NCA surface is consumed to produce LiCoO2 concurrently during calcining process. The reaction mechanism of Co3O4 & LiCoO2 composite layer is analyzed using the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS).
CRISPR-Display is a modular and flexible platform that targets natural or synthetic noncoding RNA domains to specific genomic loci for functional studies and synthetic biology.
For certain prosumer cameras, like the 30D, Canon offers two options for creative controls. Dubbed the Basic Zone and the Creative Zone, they are meant to be utilized by photographers of varying skill levels to produce great photographs. The Basic Zone, for example, uses icons to indicate automated imaging modes while the Creative Zone requires a deeper knowledge of how things work in a camera.
LiMn1−1.5xCexPO4/C (x=0, 0.01, 0.03, 0.05) are synthesized by an efficient solvothermal synthesis in water/diethylene glycol system. The structures and morphologies of all samples are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) results suggest that trivalent Ce3+ doping has no influence on the valence state of Mn2+ in LiMnPO4/C. The Ce-doped LiMn1−1.5xCexPO4/C (x≠0) materials show better cycling stability and high rate capability than the pristine LiMnPO4/C (LCe0). The Ce3+ doping content has an obvious influence on the electrochemical performances of LiMn1−1.5xCexPO4/C. After 50 cycles at 0.1C, the LiMn0.955Ce0.03PO4/C (LCe3) exhibits the highest discharge capacity of 132.3mAhg−1 (95.4 % of its initial discharge capacity), while LCe0 delivers only 115.1mAhg−1 (85.5 % capacity retention). And LCe3 also has the best high rate capability, which can still deliver 78.2mAhg−1 at 10C in comparison with 49.6mAhg−1 of LCe0. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements suggest that Ce3+ doping not only improves the electronic conductivity of LiMnPO4/C, but also facilitates the diffusion of lithium ion in bulk materials.
Electrodes of bismuth were prepared and tested as anodes for lithium ion batteries, with different particle sizes and binders, while varying the amount of active material in the mixture. Bismuth has been chosen as a “model” metal to investigate the influence of particle size on the electrochemical performance of the bismuth electrode since the potential window of Li–Bi alloys formation is relatively “high” (0.8–0.6V) and prevents other components within the electrode from being electrochemically active versus lithium in this potential window. It appears that the use of nanosized particles with large amount of binder improves the electrode cyclability but that other problems are highlighted while using such electrodes.
The purpose of this study was to monitor the dynamics of gases such as CO2 and CH4 in a soil profile with sufficient temporal resolution to observe possible diurnal variations. A computer-controlled device called a membrane probes array (MPA) was developed that consisted of 9–12 individual membrane probes installed at various soil depths. Each probe was made of a stainless steel pipe with a 1mm orifice covered with a silicone membrane. Soil gases diffuse through the membrane at a rate proportional to the ambient soil gas concentration. To measure diffusion rates, the probes are flushed with N2 one-by-one at regular time intervals and accumulated gas is detected as a spike with IR and FID analyzers. The longer the period between flushings the higher the gas accumulation and the lower the detection limit for a particular soil gas. The developed MPA agreed well with conventional manual gas sampling in West-Siberian mesotrophic fen. In peat cores with intact Carex-Sphagnum vegetation incubated under constant temperature, water level and artificial light:dark (14:10) cycles, regular diurnal oscillations of soil CO2 and CH4 occurred in the upper part of the peat core down to 19cm. Gas content in the top layer (3cm) grew during the light phase, and returned back during the dark phase. In layers further down in the soil, the same events were observed but with progressively increased time delay and lower amplitude. The obtained data agreed with the hypothesis that diurnal variations in soil CO2 and CH4 content are caused by periodic changes in intensity of root exudation that provide a major C- and energy source for soil microorganisms including methanogens. At a soil depth of 23cm, where the peak of gas bubbles occurred, the signal for both gases became chaotic and not related to the light:dark cycle.
The effect of platinum co-sputtering on the characteristics of amorphous V2O5 films, grown by dc reactive sputtering, is investigated. The co-sputtering process influences the growth mechanism as well as the characteristics of the V2O5 films. Glancing-angle X-ray diffraction (GXRD), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) results indicate that the microstructure of the V2O5 films is affected by the rf power of the co-sputtered platinum. In addition, it is found that the platinum co-sputtered V2O5 cathode film exhibits better cycleability than an undoped V2O5 cathode film. This is due to the absence of short-range order, which is generally present in undoped V2O5 cathode films. Possible explanations are given to describe the dependence of the cycleability V2O5 films on the platinum rf power and the growth mechanism of the V2O5 film.
The growing production of high-tech devices is strongly associated to a great waste of natural resources and to environmental contamination caused either by the production process of such devices as the quick disposal of them. Cell phones have stood out from the most commercialized electronic devices, which have increased the demand for rechargeable batteries which are afterward discarded before the end of its useful life. The main objective of this paper is to improve a methodology for classify the amount of NiMH and Li-Ion batteries discarded still in operating condition through concepts given to the cells. Tests with 3 NiMH and 3 Li-Ion different battery models were done. This paper also aimed to promote the efficient use of batteries cells through their reuse in academic activities related to the manufacturing of prototypes. It presents the construction of an illuminator and of a portable power supply. The results obtained showed that approximately 40% of NiMH cells and 45% of Li-Ion cells assessed were in operational condition, with charge capacity between 62% and 90%, when compared to a new cell. Such results warn about the waste of natural resources and the proposal to test the same before the final disposal.
Existing anode technologies are approaching their limits, and silicon is recognized as a potential alternative due to its high specific capacity and abundance. However, to date the commercial use of silicon has not satisfied electrode calendering with limited binder content comparable to commercial graphite anodes for high energy density. Here we demonstrate the feasibility of a next-generation hybrid anode using silicon-nanolayer-embedded graphite/carbon. This architecture allows compatibility between silicon and natural graphite and addresses the issues of severe side reactions caused by structural failure of crumbled graphite dust and uncombined residue of silicon particles by conventional mechanical milling. This structure shows a high first-cycle Coulombic efficiency (92%) and a rapid increase of the Coulombic efficiency to 99.5% after only 6 cycles with a capacity retention of 96% after 100 cycles, with an industrial electrode density of >1.6 g cm−3, areal capacity loading of >3.3 mAh cm−2, and <4 wt% binding materials in a slurry. As a result, a full cell using LiCoO2 has demonstrated a higher energy density (1,043 Wh l−1) than with standard commercial graphite electrodes.
Understanding the polarization behavior of the battery electrodes is critical to the development of high-performance lithium batteries. However, for lithium | solid polymer electrolyte (SPE) interfaces no kinetic data have been reported beyond the linear regime, which is why it has not been possible to assess the influence of this interface on the overall battery performance at higher current densities. In this work, a technique based on millisecond current pulses is presented, which enables the deconvolution of the interface and bulk effects, allowing the determination of the lithium | polystyrene-block-polyethyleneoxide (PS-b-PEO) interface kinetics over both linear and non/-linear regimes. Our results indicate that the kinetics roughly follow a hyperbolic sine law rather than a Butler-Volmer behavior. The data are described to a high degree of accuracy by a multistep model based on ion transport through a solid electrolyte interphase (SEI) and two charge-transfer steps described by the Butler-Volmer equation. Hence, it is suggested that the kinetics of the lithium | PS-b-PEO interface are controlled by three distinct processes occurring in series.
Supercritical CO2 (SCCO2) fluid, which has gas-like diffusivity, extremely low viscosity, and near-zero surface tension, is used to synthesize SnO2 nanoparticles (a 1-nm diameter is achievable), which are uniformly dispersed and tightly anchored on graphene nanosheets (GNSs) and carbon nanotubes (CNTs). The discharge capacity, rate capability, and cyclic stability of the synthesized SnO2/GNS and SnO2/CNT nanocomposites are compared. This study also tunes the SCCO2 temperature (and thus its fluid density) and finds that this factor crucially affects the SnO2 size and distribution, determining the resulting electrochemical properties. The sodiation/desodiation mechanism of the SnO2/GNS electrode is examined using synchrotron ex situ X-ray absorption and X-ray diffraction techniques, together with transmission electron microscopy. We confirm that while the oxide conversion reaction is reversible, the sluggish Sn–Na alloying/dealloying reaction is responsible for the lower measured capacity as compared to the theoretical value. The first-cycle efficiency loss is mainly attributed to the trapping of Na in the electrode surface solid electrolyte interphase layer.
Hierarchical structure SnO2 with two-dimensional (2D) nanosheets building blocks was employed as support material for Pt nanoparticles (NPs). The SnO2 supported Pt catalyst was synthesized through a facile aqueous phase process using sodium borohydride as the reducing agent. The as-prepared Pt–SnO2 catalyst exhibited remarkably improved electrocatalytic activity and stability toward methanol oxidation, in comparison with that of the commercial Pt/C catalyst and the commercial SnO2 nanopowder supported Pt catalyst. The superior catalytic performance may arise from the unique multiscale structure and morphology of the SnO2 support, which process extraordinary promotional effect on Pt catalyst.
Dimethylacetamide (DMAc) and triethyl(2-methoxyethyl)phosphonium bis(trifluoromethylsulfonyl)imide (TEMEP-TFSI) are investigated as protective additives for high voltage LiNi0.5Mn1.5O4 cathode materials. The capacity retention of Li/LiNi0.5Mn1.5O4 cells is improved by adding these additives to the base liquid electrolyte. The self-extinguishing time and DSC results demonstrate that the addition of TEMEP-TFSI to the base electrolyte is effective in reducing the flammability of the electrolyte solution and improving the thermal stability of the LiNi0.5Mn1.5O4 electrode. TEM and XPS analyses of the LiNi0.5Mn1.5O4 electrode reveal that DMAc and TEMEP-TFSI participate in the formation of a stable solid electrolyte interphase (SEI) on the LiNi0.5Mn1.5O4 electrode, and the resulting SEI layer effectively suppresses electrolyte decomposition.
Membranes are of interest for a wide variety of applications such as gas separation, water desalination, fuel cells and batteries. Because the flux across a membrane scales inversely with the membrane thickness, a thick membrane is required to achieve high selectivity, at the expense of permeability. New ultrathin membranes which promise to offer high selectivity and high permeability are highly desirable. Elemental sulfur can provide five times higher capacity than existing Li-ion cathode materials based on transition metal oxides or phosphates. Various problems have hindered the practical use of this highly attractive cathode including the insulating nature of sulfur which retards its reduction and poor electrode stability resulting in an irreversible capacity loss due to polysulfide migration from the cathode to the anode. Here we show the proof of concept for a 5 nm multilayer membrane self-assembled from commercial polyelectrolytes to encapsulate a carbon/sulfur composite and maintain the performance even at discharge rates five times more rapid than its non-encapsulated counterpart.
One of the challenges for improving the performance of lithium ion batteries to meet increasingly demanding requirements for energy storage is the development of suitable cathode materials. Cathode materials must be able to accept and release lithium ions repeatedly (for recharging) and quickly (for high current). Transition metal oxides based on the α-NaFeO2, spinel and olivine structures have shown promise, but improvements are needed to reduce cost and extend effective lifetime. In this paper, recent developments in cathode materials for lithium ion batteries are reviewed. This includes comparison of the performance characteristics of the promising cathode materials and approaches for improving their performances.
There is a renewal of interest in the use of metals that are capable of alloying with lithium as negative-electrode materials for lithium-ion batteries. These metals can supply larger capacities than graphite but their main disadvantage consists in their very limited cycle life. Indeed, they present considerable volume variations during alloying, which lead to a mechanical degradation of the electrode. The concept of an active phase stabilizing matrix was introduced. We propose in this study to associate a metal able to alloy lithium to graphite by using new preparation methods involving graphite intercalation compounds (GICs) as precursors. In one case, antimony pentachloride SbCl5 was reduced by the stage I KC8 GIC. In another case, C12SbCl5 and C24SbCl5 GICs were reduced either by gaseous caesium or by activated sodium hydride NaH. Actually, these methods led to the attention of antimony-based graphite composites in which antimony particles are deposited on the surface and edges of graphite layers or embedded in an organic matrix. Both morphological and structural characteristics of such composites were studied by transmission electron microscopy. Examination of their electrochemical properties as regards lithium insertion showed that they present interesting performances because the reversible capacity is increased by comparison with that of pure graphite and the stability of the metal is preserved throughout the cycling. The combination of graphite and antimony prevents the metal against cracking and pulverization that occur generally during alloying/dealloying cycles. Antimony-graphite composites prepared via SbCl5 reduction by KC8, via C12SbCl5 reduction by gaseous caesium or via C24SbCl5 reduction by activated NaH display improved reversible capacities of 420, 490 and 440mAhg−1, respectively.
Ionic liquid (IL) modified reduced graphene oxide (rGO–IL) nanosheets anchoring manganese oxide (Mn3O4) are synthesized via a facile solution-based growth mechanism and applied to a Zn–air battery as an effective electrocatalyst for the oxygen reduction reaction (ORR). In this study, the IL moiety in these composites increases not only the conductivity of the system, but also the electrocatalytic activity compared to pristine rGO, together with the synergic effect of facilitating the ORR with the intrinsic catalytic activity of Mn3O4. Based on the Koutecky–Levich plot, we suggest that the ORR pathway of these composites is tunable with the relative amount of Mn3O4 nanoparticles supported onto the graphene sheets; for example, the ORR mechanism of the system with a lower Mn3O4 (19.2%) nanoparticle content is similar to a Pt/C electrode, i.e., a one-step, quasi-4-electron transfer, unlike that with a higher Mn3O4 (52.5%) content, which undergoes a classical two-step, 2-electron pathway. We also demonstrate the potential of these hybrid rGO–IL/Mn3O4 nanoparticles as efficient catalysts for the ORR in the Zn–air battery with a maximum peak power density of 120 mW cm−2; a higher performance than that from commercial cathode catalysts.
Noncoding RNAs play diverse roles throughout biology and exhibit broad functional capacity. To investigate and harness these capabilities, we developed clustered regularly interspaced short palindromic repeats (CRISPR)-Display (CRISP-Disp), a targeted localization method that uses Cas9 to deploy large RNA cargos to DNA loci. We demonstrate that functional RNA domains up to at least 4.8 kb long can be inserted in CRISPR guide RNA at multiple points, allowing the construction of Cas9 complexes with protein-binding cassettes, artificial aptamers, pools of random sequences and natural long noncoding RNAs. A unique feature of CRISP-Disp is the multiplexing of distinct functions at multiple targets, limited only by the availability of functional RNA motifs. We anticipate the use of CRISP-Disp for ectopically targeting functional RNAs and ribonucleoprotein (RNP) complexes to genomic loci.
Electrochemically induced cyclization of bromoamides to β-lactams has been achieved in room-temperature ionic liquids (RTILs). The use of volatile, organic solvents (VOCs) and of supporting electrolytes may be avoided. Proton exchange reaction between amide substrates and suitable electrogenerated bases gives rise to a C4 carbanion which undergoes cyclization to β-lactam via intramolecular nucleophilic substitution (C3–C4 bond formation). β-Lactams have been isolated in good to elevated yields. The “non innocent” nature of the RTILs (imidazolium-based salts) is considered. Proton exchange reaction between N-dialkylimidazolium cation and EGB yielding N-heterocyclic carbene is discussed.