Simply Prepared Magnesium Vanadium Oxides as Cathode Materials for Rechargeable Aqueous Magnesium Ion Batteries

Vanadium-oxide-based materials exist with various vanadium oxidation states having rich chemistry and ability to form layered structures. These properties make them suitable for different applications, including energy conversion and storage. Magnesium vanadium oxide materials obtained using simple preparation route were studied as potential cathodes for rechargeable aqueous magnesium ion batteries. Structural characterization of the synthesized materials was performed using XRD and vibrational spectroscopy techniques (FTIR and Raman spectroscopy). Electrochemical behavior of the materials, observed by cyclic voltammetry, was further explained by BVS calculations. Sluggish Mg2+ ion kinetics in MgV2O6 was shown as a result of poor electronic and ionic wiring. Complex redox behavior of the studied materials is dependent on phase composition and metal ion inserted/deinserted into/from the material. Among the studied magnesium vanadium oxides, the multiphase oxide systems exhibited better Mg2+ insertion/deinsertion performances than the single-phase ones. Carbon addition was found to be an effective dual strategy for enhancing the charge storage behavior of MgV2O6. © 2022 by the authors

The Mineralogy of Natural Feldspar Hyalophane

The tectosilicates, including all polymorphic forms of SiO2 , feldspar, feldspatoids, scapolites as well as zeolites, represent one of the most represented groups of minerals in the lithosphere. The feldspars found great application in various fields of industry, especially in the field of aluminosilicate ceramics. In this paper are presented the crystalohemical and mineralogical properties of natural feldspar hyalophane.IX Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 20-21, 2021; Belgrad

Structural and Chemical Properties of Zeolite FAU-Topology

Zeolite FAU is a synthetic product formed by various process of synthesis. The unit cell of zeolite of FAU topology contains 192 (Si, Al) O4 - tetrahedra, it has tesseral symmetry and the unit cell parameter is ~ 25 A Key words: feldspar, hyalophane, crystalochemical properties.The FAU aluminosilicate network consists of a series of β-cages, which are tetrahedrally connected via D6R secondary building units. On this paper are presented the results of structural and crystalochemical analysis zeolite FAU topology. The SEM/EDS methods and X-ray powder diffraction analysis are useful for analysis.IX Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 20-21, 2021; Belgrad

Simply prepared Mg-V-O as potential cathode material for rechargeable aqueous magnesium ion batteries

Although today widely used in electronic devices and electric vehicles, lithium ion batteries encounter problem of future application, resulting from limited Li resources, relatively high costs and operational safety problems. Rechargeable magnesium batteries as a potential alternative to the Li-ion ones stand out because of their high theoretical specific capacity, high abundance of Mg resources, atmospheric stability, safety of handling, eco friendliness and low cost. Layered materials including oxides, sulphides and selenides are promising candidates for host materials for Mg2+ storage in rechargeable magnesium batteries. Slow migration of Mg2+ in the layered oxides, ascribed to the strong interaction between Mg and neighbouring O atoms, inspires researchers to look for the ways of improving their electrochemical performance. In this work, Mg-V-O material was synthesized by simple precipitation method, followed by thermal annealing. The obtained material is single-phase material consisted of MgV2O6 phase, according to the results of XRD, FTIR and Raman spectroscopy. Electrochemical test by cyclic voltammetry in aqueous solution revealed redox peaks corresponding to the insertion/deinsertion of Mg2+ ions into/from the material, but with poor current densities. In order to improve the electrochemical performance of the simply prepared Mg-V-O material, carbon was integrated with the Mg-V-O by sucrose-assisted thermal treatment. Although composed of several phases, the obtained Mg-V-O/C material exhibited around 40 times higher maximal specific current values of Mg2+ insertion/deinsertion than the Mg-V-O. Also, the electrochemical performance of the Mg-VO/ C for the insertion/deinsertion of Mg2+ ions was better than those of Al3+ and Li+ ions

Electrochemical behavior of V2O5xerogel and V2O5xerogel / graphite composite in aqueous solution

The V2O5 xerogel and V2O5 xerogel /graphite composite were synthesized by sol-gel method. The obtained materials were characterized by X-ray diffractometry and simultaneous thermogravimetry and differential thermal analysis. The electrochemical behaviour was investigated by galvanostatic cycling in aqueous solutions of LiNO3. Better electrochemical performance was evidenced for composite V2O5 xerogel/graphite. Namely, the initial capacity of V2O5 xerogel/C was found to be 66 mAh g-1 against 40.4 mA h g-1 for V2O5, while capacity fade after 50 cycles was 10 % of initial capacity for V2O5 xerogel/ graphite, against 27% for V2O5.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

The incorporation of vanadium into olivine LiFePO4/C: improvement of lithium intercalation from both organic and aqueous electrolyte

The simple and fast (malonic acid+glycine)-assisted gel-combustion process, followed by a heat treatment at 750oC under reductive atmosphere, is found to be a very effective way for the synthesis of (V-doped LiFePO4)/C composites. The Rietveld refinement confirms that vanadium incorporation into olivine structure was accompanied by the formation of iron phosphide conducting phase. The coulombic capacity and rate capability of (V-doped LiFePO4)/C composite, in both organic and aqueous electrolyte solutions, were significantly improved relative to an undoped sample, as revealed by both galvanostatic cycling and cyclic voltammetry. The average discharging capacities of ~5mol.%V-doped LiFePO4/C composite in an aqueous LiNO3 solution were 91, 73 and 35 mAh g-1 at 1, 10 and 100 C, respectively, with no perceivable capacity fade upon 100 charging/discharging cycles

What Happens When BiFeO3 Undergoes Potentiodynamic Polarization?

Unlike its ferroelectric and magnetic properties [1], the electrochemical behavior of bismuth ferrite, BiFeO3 (BFO) has received less attention [2]. In this contribution, BFO was hydrothermally synthesized [3] to be examined as an electrode for metal- ion aqueous rechargeable batteries. BFO powder was first investigated in terms of structural and surface properties using X-ray diffraction and Thermally-Programmed Desorption methods and then characterized in Li and Na- containing aqueous electrolytes using Cyclic Voltammetry and Chronopotentiometry. BFO was found to be inactive within the electrochemical potential window of the aqueous electrolyte. However, its ability to be electrochemically transformed, under deep cathodic polarization, results in an active phase composed of Bi- and Fe-based oxides, as confirmed by Fourier-transform infrared and Raman spectroscopy. The redox behavior of BFO-derived oxide electrode is compared in both Li and Na -based aqueous electrolytes and discussed in the context of tailoring electrochemical properties for safe and sustainable metal-ion batteries

Pseudocapacitance behavior of polyaniline in aerated HC1 and H2SO4 solutions

High conducting polyaniline (PANI) nanofibres deposited onto glassy carbon support were studied in sulphuric (1mol dm-3 H2SO4) and hydrochloric (1mol dm-3 HCl) acid by both potentiodynamic and complex impedance methods. A large charge storage capacity was obtained in each of investigated acid solutions, particularly in HCl one. For instance, specific capacity amounting to 340 Fg-1 was observed potentiodynamically in 1mol dm-3 HCl at a scan rate of 10 mVs-1

A ternary PEDOT-TiO2-reduced graphene oxide nanocomposite for supercapacitor applications

A ternary composite of PEDOT was prepared with TiO2 via emulsion polymerization method adjusting various weight ratios of TiO2 to PEDOT and synthesized rGO was then blended with this composite. The FTIR, UV–Vis and XRD analysis displayed characteristic features of PEDOT and TiO2. The morphology of the nano-hybrid structure was additionally investigated by SEM analysis. Pore size and surface area analysis of particles were characterized by BET method. The electrochemical analysis showed that the specific capacitance (Csp) for PEDOT-TiO2-15-rGO was 18.9 F.cm-2 at 0.1 mA g-1 current density

Mechanism and clinical importance of respiratory failure induced by anticholinesterases

© 2017, University of Kragujevac, Faculty of Science. All rights reserved. Respiratory failure is the predominant cause of death in humans and animals poisoned with anticholinesterases. Organophosphorus and carbamate anticholinesterases inhibit acetylcholinesterase irreversibly and reversibly, respectively. Some of them contain a quaternary atom that makes them lipophobic, limiting their action at the periphery, i.e. outside the central nervous system. They impair respiratory function primarily by inducing a desensitization block of nicotinic receptors in the neuromuscular synapse. Lipophilic anticholinesterases inhibit the acetylcholinesterase both in the brain and in other tissues, including respiratory muscles. Their doses needed for cessation of central respiratory drive are significantly less than doses needed for paralysis of the neuromuscular transmission. Antagonist of muscarinic receptors atropine blocks both the central and peripheral muscarinic receptors and effectively antagonizes the central respiratory depression produced by anticholinesterases. To manage the peripheral nicotinic receptor hyperstimulation phenomena, oximes as acetylcholinesterase reactivators are used. Addition of diazepam is useful for treatment of seizures, since they are cholinergic only in their initial phase and can contribute to the occurrence of central respiratory depression. Possible involvement of central nicotinic receptors as well as the other neurotransmitter systems - glutamatergic, opioidergic - necessitates further research of additional antidotes