Revitalized interest in vanadium pentoxide as cathode material for lithium-ion batteries and beyond

In recent years, there is a growing interest in studying the dielectric behavior of biopolymer composites due to their potential application as a dielectric material in various electronic devices such as microchips, transformers, and circuit boards. Conducting electroactive polymer composites have also been investigated for various potential applications which include biological, biomedical, flexible electrodes, display devices, biosensors, and cells for tissue engineering. In this chapter, the preparation and dielectric behavior of various biopolymer composites is presented. These biopolymer composites generally consist of nanoscale metal nanoparticles and carbon-based nanofillers such as carbon nanotubes, graphene, graphene oxide (GO), etc., dispersed into the polymer matrix. The physical and chemical properties of these fillers and their interactions with polymers have a significant effect on the microstructure and the final properties of nanocomposites. The biopolymer composites with excellent dielectric properties show great promise as an energy storage dielectric layer in high-performance capacitor applications such as embedded capacitors. This chapter highlights some of the examples of such biopolymer composites; their processing and dielectric behavior will be discussed in detail.

Biopolymer Composites With High Dielectric Performance: Interface Engineering

This study focused on the glass forming, crystallization, and physical properties of ZnO doped MgO-Al2O3-SiO2-B2O3 glass-ceramics. The results show that the glass forming ability enhances first with ZnO increasing from 0 to 0.5 mol%, and then weakens with further addition of ZnO which acted as network modifier. No nucleating agent was used and the crystallization of studied glasses is controlled by a surface crystallization mechanism. The predominant phase in glass-ceramics changed from α-cordierite to spinel/gahnite as ZnO gradually replaced MgO. The phase type did not change; however, the crystallinity and grain size in glass-ceramics increased when the glasses were treated from 1030 °C to 1100 °C. The introduction of ZnO can improve the thermal, mechanical, and dielectric properties of the glass-ceramics. The results reveal a rational mechanism of glass formation, crystal precipitation, and evolution between structure and performance in the xZnO-(20-x)MgO-20Al2O3-57SiO2-3B2O3 (0 ≤ x ≤ 20 mol%) system.

Glass forming, crystallization, and physical properties of MgO-Al2O3-SiO2-B2O3 glass-ceramics modified by ZnO replacing MgO

A polymer-based magnesium (Mg) electrolyte is vital for boosting the development of high-safety and flexible Mg batteries by virtue of its enormous advantages, such as significantly improved safety, potentially high energy density, ease of fabrication, and structural flexibility. Herein, a novel polytetrahydrofuran-borate-based gel polymer electrolyte coupling with glass fiber is synthesized via an in situ crosslinking reaction of magnesium borohydride [Mg(BH4 )2 ] and hydroxyl-terminated polytetrahydrofuran. This gel polymer electrolyte exhibits reversible Mg plating/stripping performance, high Mg-ion conductivity, and remarkable Mg-ion transfer number. The Mo6 S8 /Mg batteries assembled with this gel polymer electrolyte not only work well at wide temperature range (-20 to 60 °C) but also display unprecedented improvements in safety issues without suffering from internal short-circuit failure even after a cutting test. This in situ crosslinking approach toward exploiting the Mg-polymer electrolyte provides a promising strategy for achieving large-scale application of Mg-metal batteries.

A Crosslinked Polytetrahydrofuran-Borate-Based Polymer Electrolyte Enabling Wide-Working-Temperature-Range Rechargeable Magnesium Batteries.

Structural and magnetic properties of magnesium ferrite nanoparticles prepared via EDTA-based sol-gel reaction

Controlling the composition, microstructure, electrical and magnetic properties of LiFe5O8 powders synthesized by sol gel auto-combustion method using urea as a fuel

Structure and electrical properties of ZnO doped barium-metaphosphate glasses

Nano-structure pure barium titanate BaTiO3 (BT) and (BT) co-doped with constant concentration of Er3+ ions and different concentrations of Yb3+ ions were prepared using sol–gel method. XRD results confirmed that the pure sample was found to crystallize in tetragonal phase by sintering at 750 °C for 1 h. All major peaks corresponding to perovskite BT phase appeared. Efficient infrared-to-visible up-conversion is reported in the doped samples. The conversion process and results in the generation of visible emissions are discussed. Up-conversion efficiency for red emission predominates in doped samples. Results illustrate the large potential of this class of materials for photonic applications in optoelectronics devices.

Detection of up-conversion in nano-structure BaTiO3 co-doped with Er3+ and Yb3+ ions

Nanocrystalline Ni 0.7− y Zn 0.3 Ca y Fe 2 O 4 (0.0 ≤  y  ≤ 0.7) has been obtained by soft coprecipitation method at different calcination temperatures. The influence of Ca 2+ content and heat treatment on microstructure and magnetic properties are investigated using X-ray diffraction (XRD), thermal analysis, scanning electron microscope (SEM), atomic force microscope (AFM) and infrared (IR) spectroscopy. XRD analysis reveals single phase of spinel structure in ferrite with y  = 0.2. An endothermic peak in DSC curve is appeared around 700 °C for all compositions due to collapse of the defective surface layer covers the grains. IR spectra for precursors or calcined ferrites shows the existence of bands characteristic for cubic spinel phase. The higher values for specific saturation magnetization ( M s ) was obtained for ferrites calcined at 600 °C. Paramagnetic ordered particles was dominated when Ca 2+ content increases more than 0.3. On the other hand, the coercivity of the present ferrites is strongly depends on Ca 2+ content than calcination temperature.

Structural and magnetic properties of nanograined Ni0.7−yZn0.3CayFe2O4 spinels

In this study, the effect of vanadium pentoxide (V2O5) on the electrical, dielectric, and optical properties of poly(vinyl alcohol) (PVA)/V2O5 nanocomposites was examined. The PVA/V2O5 nanocomposites were prepared by solution mixing, followed by film casting. The as-prepared films were characterized by X-ray diffraction, thermogravimetric analysis, as well as impedance spectroscopy. The obtained results indicated that, with increasing V2O5 content, the PVA composite exhibits considerable vestige of crystallization and the PVA peaks become broader. The electrical conductivity, σ
 dc, increases as the temperature and the dopant level of V2O5 increase. The frequency dependence of alternating current conductivity was governed by a critical frequency, ω
 p. The values of ω
 p are found to be thermally activated. The loss tangent (tan δ) shows a peak with the frequency, which indicates a dielectric relaxation in these composites with relaxation time decreases with both temperature and V2O5 content increase. Optical absorption edge and direct and indirect energies for all mentioned samples were determined and discussed.

N. M. Shash

Papers

Controlling the composition, microstructure, electrical and magnetic properties of LiFe5O8 powders synthesized by sol gel auto-combustion method using urea as a fuel

Structure and electrical properties of ZnO doped barium-metaphosphate glasses

Detection of up-conversion in nano-structure BaTiO3 co-doped with Er3+ and Yb3+ ions

Structural and magnetic properties of nanograined Ni0.7−yZn0.3CayFe2O4 spinels

Effect of vanadium pentoxide on the electrical, dielectric, and optical properties of poly(vinyl alcohol)/vanadium pentoxide nanocomposites