Ranveer Kumar

Impedance Spectroscopy and FTIR Studies of PEG - Based Polymer Electrolytes

Ionic conductivity of poly(ethylene glycol) (PEG) - ammonium chloride (NH4Cl) based polymer electrolytes can be enhanced by incorporating ceramic filler TiO2 into PEG-NH4Cl matrix. The electrolyte samples were prepared by solution casting technique. FTIR studies indicates that the complex formation between the polymer, salt and ceramic filler. The ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity of the electrolyte varies with TiO2 concentration and temperature. The highest room temperature conductivity of the electrolyte of 7.72×10−6 S cm-1 was obtained at 15% by weight of TiO2 and that without TiO2 filler was found to be 9.58×10−7 S cm−1. The conductivity has been improved by 8 times when the TiO2 filler was introduced into the PEG–NH4Cl electrolyte system. The conductance spectra shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the conductivity of the polymer electrolytes seems to obey the VTF relation. The conductivity values of the polymer electrolytes were reported and the results were discussed. The imaginary part of dielectric constant (ei) decreases with increase in frequency in the low frequency region whereas frequency independent behavior is observed in the high frequency region.

Ionic Conductivity and Discharge Characteristic Studies of PVA-Mg(CH3COO)2 Solid Polymer Electrolytes

Ion conducting solid polymer electrolytes based on a polymer polyvinyl alcohol (PVA) complexed with magnesium acetate (Mg(CH3COO)2) were prepared by solution cast technique. Various experimental techniques, such as XRD, DSC, composition-dependent conductivity, temperature-dependent conductivity, and transport number measurements are used to characterize these polymer electrolyte films. The transference number data indicated the dominance of ion-type charge transport in these polymer electrolyte systems. An electrochemical cell with the configuration Mg/(80PVA + 20Mg(CH3COO)2)/(I2 + C + electrolyte) has been fabricated and its discharge characteristics were studied. The Open Circuit Voltage (OCV) is 1.84 V.

Preparation and characterization of pva based solid polymer electrolytes for electrochemical cell applications

Solid polymer electrolyte films containing poly(vinyl alcohol) (PVA) and magnesium nitrate (Mg(NO3)2) were prepared by solution casting technique and characterized by using XRD, FTIR, DSC and AC impedance spectroscopic analysis. The amorphous nature of the polymer electrolyte films has been confirmed by XRD. The complex formation between PVA and Mg salt has been confirmed by FTIR. The glass transition temperature decreases with increasing the Mg salt concentration. The AC impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte films in the range of 303–383 K, and the temperature dependence seems to obey the Arrhenius behavior. Transport number measurements show that the charge transport is mainly due to ions. Electrochemical cell of configuration Mg/(PVA + Mg(NO3)2) (70:30)/(I2 + C + electrolyte) has been fabricated. The discharge characteristics of the cell were studied for a constant load of 100 kΩ.

Ion-Conducting Polymer Electrolyte Based on Poly (Ethylene Glycol) Complexed with Mg(CH3COO)2– Application as an Electrochemical Cell

A new Mg2+ -ion conducting polymer electrolyte based on Poly (ethylene glycol) complexed with Mg(CH3COO)2 has been prepared using solution-cast technique. DSC, Composition-dependent conductivity at different temperatures, dielectric studies, and transference number measurements have been performed to characterize the polymer electrolytes. The DSC measurements show decrease in melting point with increase in salt concentration. Out of five different compositions studied, the 85PEG: 15Mg(CH3COO)2 polymer-salt complex showed the highest conductivity with σ = 1.07 x 10-6 S/cm at room temperature (30°C). The transport number measurements have shown that the electrolyte is an ionic conductor. Using the electrolyte, an electrochemical cell with the configuration Mg/(PEG+Mg(CH3 COO)2)/(I2 +C+electrolyte) has been fabricated and its discharge characteristics studied.

Effect of precursors ratio on crystallinity and thermal stability of CH3NH3PbI3

CH3NH3PbI3 is a newly developed organic inorganic perovskite light harvesting (OIPLH) material which is using for different electronic applications. In this work, we have synthesized CH3NH3PbI3 with different ratio of precursor CH3NH3I and PbI2. We have tried to explain how the ratio of precursors affected the crystallinity and thermal stability of OIPLH material. XRD study of material shows that, crystallinity of material losses on increasing the precursor ratio and simultaneous thermal analysis (TGA/DTA) indicates the more thermal decomposition with increasing precursor ratio due to excess amount of CH3NH3I.

Effect of TiO2 ceramic filler on PEG-based composite polymer electrolytes for magnesium batteries

Composite polymer electrolyte films consisting of polyethylene glycol (PEG), Mg(CH3COO)2 and Al2O3 particles have been prepared by solution casting technique. The X-ray diffraction patterns of PEG-Mg(CH3COO)2 with Al2O3 ceramic filler, indicates the decrease in the degree of crystallinity with increasing concentration of the filler. The role of ceramic phase is to reduce the melting temperature which is ascertained from the DSC. The effect of ceramic filler on the conductivity of the polymer electrolyte was studied. The maximum ionic conductivity has been observed for 10 wt% of Al2O3 at room temperature (303 K). The transference number data indicated the dominance of ion-type charge transport in these composite polymer electrolytes. Using this (PEG-Mg(CH3COO)2-Al2O3) (85–15–10) electrolyte, solid-state electrochemical cell was fabricated and their discharge profiles were studied under a constant load of 100 kΩ. Several cell profiles associated with this cell were evaluated and are reported. Copyright

AC conductivity and electrochemical studies of PVA/PEG based polymer blend electrolyte films

Polymer blend electrolyte films based on Polyvinyl alcohol(PVA)/Poly(ethylene glycol)(PEG) and magnesium nitrate (Mg(NO3)2) were prepared by solution casting technique. Conductivity in the temperature range 303-373 K and transference number measurements have been employed to investigate the charge transport in this polymer blend electrolyte system. The highest conductivity is found to be 9.63 × 10−5 S/cm at 30°C for sample with 30 weight percent of Mg(NO3)2 in PVA/PEG blend matrix. Transport number data shows that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this electrolyte, an electrochemical cell with configuration Mg/(PVA+PEG+Mg(NO3)2)/(I2+C+electrolyte) was fabricated and its discharge characteristics profile has been studied.

Structural and thermodynamic aspects of organic-inorganic mixed halide (CH3NH3PbI3-xBrx) perovskite

Mixed Bromine and iodine lead halide perovskite CH3NH3PbI3-xBrx have been synthesized by solution phase method using CH3NH3I and PbBr2 precursors in ambient conditions. X-ray diffraction indicates the formation of cubic perovskite at room temperature with space group of Pm3m. The mixed perovskite improved crystallanity and grain contour which may significant improve photovoltaic performance of perovskite devices. Thermodynamic behavior of such type of material also indicates energy absorption nature of materials.Mixed Bromine and iodine lead halide perovskite CH3NH3PbI3-xBrx have been synthesized by solution phase method using CH3NH3I and PbBr2 precursors in ambient conditions. X-ray diffraction indicates the formation of cubic perovskite at room temperature with space group of Pm3m. The mixed perovskite improved crystallanity and grain contour which may significant improve photovoltaic performance of perovskite devices. Thermodynamic behavior of such type of material also indicates energy absorption nature of materials.

Role of organic and inorganic cations on thermal behavior of lead iodide perovskites

Recently, organic-inorganic perovskite materials have attracted much attention due to their enormous potential for use in future of new sustainable energy sources. However, fabrication of environmental friendly perovskite and achieving better stability is a major concern towards the commercialization. Here we study the role of cations in the perovskite powder and their influence upon thermodynamic stability. In this study we find, inorganic (cesium, Cs+) cation is shown to be more efficient in the thermal stabilization of the perovskite material than organic (methylamine, CH3NH2+) cation. This study reviles that stability of perovskite can be improved by incorporation of inorganic cation.

Frequency and Temperature Dependence of Conductivity Studies of New Silver‐Calcia‐Borate Glass System

Present paper deals with frequency and temperature dependence of conductivity studies of a new 0.7[0.75AgI:0.25AgCl]:0.3[Ag2O:{B2O3:CaO}] Silver‐Calcia‐Borate glass system. The optimum conducting composition (x = 0.7) were synthesized by two different routes (i) by melt quench method and (ii) by annealing the sample at 900 °C. Temperature dependence of conductivity has been reported for both quenched and annealed systems. Thermal heating and cooling cycles of these systems were done for the optimum conducing composition. Frequency dependence of conductivity on OCC of quenched system at different temperatures has also been reported.