Recycling of Primary Lithium Batteries Production Residues

Production waste of primary lithium batteries constitutes a considerable secondary lithium feedstock. Although the recycling of lithium batteries is a widely studied field of research, the metallic residues of non-rechargeable lithium battery production are disposed of as waste without further recycling. The risks of handling metallic Li on a large scale typically prevent the metal from being recycled. A way out of this situation is to handle Li in an aqueous solution, from where it can be isolated as Li₂CO₃. However, the challenge in hydrometallurgical treatment lies in the high energy release during dissolution and generation of H₂. To reduce these process-related risks, the Li sheet metal punching residues underwent oxidative thermal treatment from 300 to 400 °C prior to dissolution in water. Converting Li metal to Li₂O in this initial process step results in an energy release reduction of ∼70 %. The optimal oxidation conditions have been determined by experimental design varying three factors: temperature, Li metal sheet thickness, and residence time. With 96.9±2.6 % almost the entire Li amount is converted to Li₂O, after 2.5 h treatment at 400 °C for a Li sheet thickness of 1.99 mm. Final precipitation with CO₂ yields 85.5±3.0 % Li₂CO₃. Using pure Li sheets, the product Li₂CO₃ is obtained in battery-grade quality (>99.5 %). Non-precipitated Li is recirculated into the process on the stage of dissolving Li₂O, thus avoiding loss of material.     

Charge‐Induced Unzipping of Isolated Proteins to a Defined Secondary Structure

Here we present a combined experimental and theoretical study on the secondary structure of isolated proteins as a function of charge state. In infrared spectra of the proteins ubiquitin and cytochrome c, amide I (C=O stretch) and amide II (N–H bend) bands can be found at positions that are typical for condensed‐phase proteins. For high charge states a new band appears, substantially red‐shifted from the amide II band observed at lower charge states. The observations are interpreted in terms of Coulomb‐driven transitions in secondary structures from mostly helical to extended C₅‐type hydrogen‐bonded structures. Support for this interpretation comes from simple energy considerations as well as from quantum chemical calculations on model peptides. This transition in secondary structure is most likely universal for isolated proteins that occur in mass spectrometric experiments.     

Equilibrium and kinetic studies for the adsorption of benzene and toluene by graphene nanosheets: a comparison with carbon nanotubes

In this study, graphene nanosheets (GNSs) were adopted as an adsorbent to investigate their characterizations and performance for adsorbing benzene and toluene in aqueous solutions. In order to determine the best fit model for each considered system, nonlinear regressions were used. Experimental data of adsorption were corroborated by the combined Langmuir–Freundlich (Sips) models for the isotherms and pseudo‐first‐order model for the kinetics. As a result, GNSs displayed high affinity to the aromatic hydrocarbons such as benzene and toluene. The high affinity was dominated by π–π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS's surfaces. Hydrophobic properties and molecular sizes of benzene and toluene affected the adsorption of GNS. In addition, the favorable adsorption of toluene possibly was due to the increase in the molecular weight, decrease in the solubility, and the increase in the boiling point. A comparative study on the benzene and toluene adsorption revealed that favorable adsorption of GNSs compared with that of carbon nanotubes was consistent with the order of physical properties such as specific surface area and pore's volume. Copyright © 2016 John Wiley & Sons, Ltd.     

3D-structured carbon-coated MnO/graphene nanocomposites with exceptional electrochemical performance for Li-ion battery anodes

MnO has a high theoretical capacity, moderate discharge plateau, and low polarization when it is used as the anode material in lithium battery. However, the issues that limit its application are its poor conductivity and large volume changes, which can easily result in the collapse of electrode structure during long-term cycling. In the present work, a carbon-coated MnO/graphene 3D-network anode material is synthesized by an electrostatic adsorption of dispersed precipitates precipitation method. The MnO nanoparticles coated by carbon are uniformly distributed on the surface of graphene nanosheets and form a 3D sandwich-like nanostructure. A carbon layer is coated on the surface of MnO nanoparticles, which slows down the volume expansion in the process of lithium intercalation. The graphene nanosheets are cross-linked through carbons in this 3D nanostructure, which provides mechanical support and effective electron conduction pathways during the charge-discharge. The electrochemical tests indicate that the prepared 3D carbon-coated MnO/graphene electrode exhibits an excellent rate capacity of 1247.3 and 713.2 mAh g^?1 at 100 and 1000 mA g^?1, respectively. The capacity is 792.2 mAh g^?1 after long cycle at a current density of 1000 mA g^?1. The specific capacity is higher than that of MnO-based composite lithium anode materials currently reported. The superior rate and cycling performances are attributed to the unique 3D-network structure, which provides an effectively conductive network, buffers volume expansion, and prevents falling and aggregation of MnO in the charge and discharge process of the electrode materials. The 3D-structured carbon-coated MnO/graphene anode material will have an excellent application prospect.

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Graphical abstract Cyclic performance at 1 A g^?1 and SEM images (inset) of the 3D-structured carbon-coated MnO/graphene nanocomposite.

     

Synthesis,Crystal Structure and Fluorescent Study of Bis(2-(2-hydroxyphenyl)benzimidazolate)zinc with Ethanol Solvate

Abstract  The zinc(II) complex with 2-(2-hydroxyphenyl)benzimidazole, namely [Zn(2-(2-hydroxyphenyl)benzimidazolate)₂]·C₂H₅OH (1 · C₂H₅OH) has been synthesized and characterized by X-ray crystallography and photoluminescent analysis. The complex crystallizes in monoclinic space group P2₁/c with cell parameters a = 10.156(1) ?, b = 25.771(3) ?, c = 9.674(1) ?, α = 90°, β = 103.641(2)°, γ = 90°, Z = 4, V = 2460.4(4) ?³. The central Zn(II) is four-coordinate and has a tetrahedral geometry. The steady-state and time-resolved photoluminescent spectra for the title compound have also been studied. The emission property can be ascribed to ligand-centered charge-transfer transition (LCCT) with π → π* property. Index Abstract   A new co-crystal of Zn(II) complex of 2-(2-hydroxylphenyl)benzimidazole with ethanol solvate has been prepared, characterized by X-ray crystallography and fluorescent studies.      

On damping coefficient due to phase transformation

The damping coefficient of capillary waves due to the evaporation-condensation process at the interface of the two phases of a fluid is evaluated. To highlight the mechanism of the effect of heat and mass transfer across the interface between regions of liquid and vapor, potential flow of incompressible fluids are assumed. Thus other mechanisms of damping are neglected. To fascilitate the analysis, the method of multiple-scale is employed in the analysis, even though the problem is linear.     

Safety margin criterion of nonlinear unbalance elastic axle system

IntroductionAtpresentanewanddevelopingsubject—chaoticdynamicsstartsabroadprospectforanalysisofnonlinearsystem[1～ 5 ].Largerotatingmachineryisatypicalnonlinearnon_autonomoussystem .Thesaferunofrotorsystemisofgreatsignificancetosociallifeandeconomicdevelopment.Thestabilityisthekeytosafeoperation .Thesafestabilityanalysisandcontrolforlargesystemisnotonlyamajorbasicresearchbutalsoisveryimportanttosolvethesafeproblemsinlifeandproduction[6 ,7].Soar,althoughmanymathematicians,mechanistsandengineer…     

Flow properties of a dusty-gas point source in a supersonic free stream

By using Lagrangian method, the flow properties of a dusty-gas point source in a supersonic free stream were studied and the particle parameters in the near-symmetry-axis region were obtained . It is demonstrated that fairly inertial particles travel along oscillating and intersecting trajectories between the bow and termination shock waves . In this region, formation of " mufti- layer structure" in panicle distribution with alternating low- and high density layers is revealed. Moreover, sharp accumulation of particles occurs near the envelopes of particle trajectories .     

Dynamic modeling and simulation of deploying process for space solar power satellite receiver

To reveal some dynamic properties of the deploying process for the solar power satellite via an arbitrarily large phased array (SPS-ALPHA) solar receiver, the symplectic Runge-Kuttamethod is used to simulate the simplified model with the consideration of the Rayleigh damping effect. The system containing the Rayleigh damping can be separated and transformed into the equivalent nondamping system formally to insure the application condition of the symplectic Runge-Kutta method©First, the Lagrange equation with the Rayleigh damping governing the motion of the system is derived via the variational principle. Then, with some reasonable assumptions on the relations among the damping, mass, and stiffness matrices, the Rayleigh damping system is equivalently converted into the nondamping system formally, so that the symplectic Runge-Kutta method can be used to simulate the deploying process for the solar receiver. Finally, some numerical results of the symplectic Runge-Kutta method for the dynamic properties of the solar receiver are reported. The numerical results show that the proposed simplified model is valid for the deploying process for the SPS-ALPHA solar receiver, and the symplectic Runge-Kutta method can preserve the displacement constraints of the system well with excellent long-time numerical stability.     

Chronology and origin of VMS deposits in Xinjiang,NW China

VMS deposits in Xinjiang, NW China are widespread in the Altay, Tianshan and West Kunlun orogenic belt, mainly formed during the Proterozoic rifting and Phanerozoic post-orogenic extension and are related to the bimodal volcanism. The VMS deposits are middle and small in scale. According to assemblages of metallogenetic elements, they can be divided into four types (Cu-Zn, Cu-S, Pb-Zn-Cu and Pb-Zn types) with the Cu-Zn and Pb-Zn types being the most important ones. Research of isotopic chronology shows that the VMS deposits in Xinjiang were formed during the Proterozoic, Ordovician, Deovonian, Carboniferous and Permian periods and usually underwent multi-stage mineralization, especially the large-sized deposits usually have post-volcanic superimposed mineralization by tectonomagmatic or metamorphic hydrothermal metal-logenic fluids.