U.V. Subba Rao

Ion-conducting polymer electrolyte based on poly (ethylene oxide) complexed with NaNO3 salt-application as an electrochemical cell

Abstract Solid polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with sodium nitrate (NaNO 3 ) have been prepared by a solution-cast technique. The complexation of NaNO 3 salt with PEO has been confirmed by X-ray diffraction, infrared (IR) and optical microscopic studies. Measurements of the dc conductivity in the temperature range 303 to 373 K and the transference numbers have been carried out to investigate the charge transport in this polymer electrolyte system. Transport number data show that the charge transport in this polymer electrolyte system is predominantly due to ions. Using the polymer electrolyte, solid-state electrochemical cells have been fabricated. The various cell parameters are evaluated and reported.

Study of the plasticizer effect on a (PEO+NaYF4) polymer electrolyte and its use in an electrochemical cell

Abstract Poly(ethylene oxide) (PEO)-based solid polymer electrolyte films with NaYF4 and NaYF4+plasticizer (dimethyl formamide) have been prepared by the solution-cast technique. Various experimental techniques have been used, such as electrical conductivity (composition dependence, temperature dependence in the temperature range 303–400 K) and transport number measurements, to characterise these polymer electrolyte films. The conductivity–temperature plots showed an increase in conductivity with increasing temperature. The increase in conductivity is about 10 times larger in the plasticizer-added (PEO+NaYF4) polymer electrolyte system compared with the pure (PEO+NaYF4) polymer electrolyte system. Electrochemical cells of configuration Na/(PEO+NaYF4+plasticizer)/(I2+C+electrolyte) have been fabricated. The discharge characteristics of the cells were studied for a constant load of 100 kΩ. The open circuit voltage (OCV), short circuit current (SCC), discharge time for the plateau region, etc., were evaluated and compared with data from our earlier reported (PEO+NaYF4) electrochemical cells.

Development of electrochemical cells based on (PEO + NaYF4) and (PEO + KYF4) polymer electrolytes

Abstract Thin film ion conducting polymer electrolytes based on polyethylene oxide (PEO) complexed with NaYF4 and KYF4 salts have been prepared using the solution-cast technique. The complexation of NaYF4 and KYF4 salts with PEO were confirmed by infra-red and X-ray diffraction studies. The results of the electrical conductivity and transference number measurements in these electrolytes have been reported. Electrochemical cells with the polymer electrolytes (PEO+NaYF4) and (PEO+KYF4) have been fabricated with the configuration Na-(PEO + NaYF4)-(I2 + C + electrolyte) and K-(PEO + KYF4)-(I2 + C + electrolyte) respectively and their discharge characteristics studied. The open circuit voltages and short circuit currents were respectively found to be 2.45 V and 560 μA for the NaYF4 complexed cell and 2.4 V and 140 μA for the KYF4 complexed cell. Several other cell parameters have been evaluated and reported.

Ionic conductivity and battery characteristic studies on PEO+AgNO3 polymer electrolyte

Abstract A new Ag + ion conducting polymer electrolyte based on PEO+AgNO 3 system is reported. The solvation of Ag + ion with PEO is confirmed by XRD studies. The electrical conductivity and cell discharge characteristics at room temperature (32°C) are reported. The highest conductivity (9.2×10 −3 S cm −1 ) has been observed for 80:20 composition (i.e. Ag + / E 0 =0.6). An electrochemical cell with the configuration Ag/PEO+AgNO 3 / (I 2 +C+electrolyte) has also been studied [for which open circuit voltage (OCV)=610 mV and short circuit current (SCC)=4.4.×10 −6 A] and a number of cell parameters obtained are reported.

Ion conducting polymer electrolyte films based on (PEO + KNO3) system and its application as an electrochemical cell

Abstract Ion conducting polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with potassium nitrate (KNO3) have been prepared by solution-cast technique. The complexation of KNO3 salt with the polymer PEO has been confirmed by X-ray diffraction (XRD) and Infrared (IR) studies. DC conductivity in the temperature range 303–373 K and transference number measurements have been employed to investigate the charge transport in this polymer electrolyte system. Transport number data have shown that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this polymer electrolyte, solid state electrochemical cells have been fabricated. Various cell parameters associated with these cells are evaluated and reported.

Ion transport and electrochemical cell characteristic studies of a new (PVP 1 NaNO3) polymer electrolyte system

Polymer electrolyte films based on poly (vinyl pyrrolidone) (PVP) complexed with NaNO3 salt have been prepared by solution—cast technique. Several experimental techniques such as X-ray diffraction, Infrared (IR), DC—electrical conductivity, transference number measurements have been employed to characterize the polymer electrolyte. The conductivity of the (PVP + NaNO3) electrolyte is about 104 times larger than that of pure PVP at room temperature. The transference number measurements show that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this polymer electrolyte, an electrochemical cell with the configuration Na/(PVP + NaNO3)/(I2 + C + electrolyte) has been fabricated and its discharge characteristics studied. The open circuit voltage (OCV) and short circuit current (SCC) observed for the cell are 2.65 V and 1.1 mA respectively. A number of other cell parameters evaluated are also reported.

Study of transport and electrochemical cell characteristics of PVP:NaClO3 polymer electrolyte system

Abstract A solid polymer electrolyte system based on poly(vinyl pyrrolidone) (PVP) complexed with sodium chlorite (NaClO 3 ) salt has been prepared by a solution — cast technique. Several experimental techniques, such as composition-dependence conductvity, temperature-dependence conductivity in the temperature range of 303–398xa0K and transport number measurements, have been employed to characterize this polymer electrolyte system. The conductivity of the (PVP+NaClO 3 ) electrolyte is about 10 4 times larger than that of pure PVP at room temperature. Transport number measurements show that the charge transport is mainly due to ions. An electrochemical cell with the configuration Na/(PVP+NaClO 3 )/(I 2 +C+electrolyte) has been fabricated and its discharge characteristics studied. The open-circuit voltage and short-circuit current are 2.77xa0V and 1.35xa0mA, respectively. A number of other cell parameters are reported.

Conductivity and discharge characteristic studies of novel polymer electrolyte based on PEO complexed with Mg(NO3)2 salt

Abstract Films of a new ion conducting polymer electrolyte based on polyethylene oxide (PEO) complexed with Mg(NO3)2 salt have been prepared by a solution-casting technique. The solvation of the salt with PEO has been confirmed by X-ray diffraction studies. dc conductivity and transference number measurements have been done to investigate the order of conductivity and the charge transport in this polymer electrolyte. The transference number measurements have shown that the charge transport in this electrolyte is predominantly due to ions (tion ≈ 0.96). The order of conductivity is found to increase with an increase in the concentration of the salt in the polymer and also with an increase of temperature. Using this electrolyte, an electrochemical cell has been fabricated and its discharge characteristics have been studied for different loads. The results show that Mg polymeric electrolytes offer an interesting alternative to lithium systems for RT solid state battery systems.

Polymer electrolyte system based on (PEO+KBrO3) — its application as an electrochemical cell

Abstract Ion-conducting polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with potassium bromate (KBrO 3 ) are prepared by a solution-cast technique. Several experimental techniques such as differential scanning calorimetry (DSC), dc-conductivity and transference number measurements are employed to characterise this polymer electrolyte system. The conductivity–temperature plots show two regions in the temperature range of study and transport number data which indicate that the charge transport in this electrolyte system is predominantly due to ions. Using these polymer electrolyte films, solid-state electrochemical cells are fabricated and their discharge characteristics are examined for a constant load of 100xa0kΩ. Several cell parameters associated with the cells are evaluated and reported.

Magnetism and superconductivity in the 2:2:1:2 bismuth cuprate by dysprosium substitution (Bi2Sr2Ca1-xDyxCu2O8+δ)

Abstract Magnetic and superconducting properties of the solid solution Bi2Sr2[Ca1−xDyx]1Cu2O8+Δ are reported. It is shown that substitution of Dy3+ for Ca2+ as well as appropriate annealings at moderate temperatures (300°C ⩽ T ⩽ 500°C), are efficient methods to optimize the critical temperature of the 2 : 2 : 1 : 2 bismuth cuprate. Emphasis is given to the interplay between magnetism and superconductivity in these materials. Results show that the dysprosium substitution is responsible for the magnetic properties in both the normal and superconducting states but, at the same time, it provides additional electrons which change the hole carrier density. As a consequence, paramagnetic domains would grow at the expense of the superconducting regions and will suppress superconductivity at x ∼ 0.5.