Decoupled ion conduction mechanism of poly(vinyl alcohol) based Mg-conducting solid polymer electrolyte

Polyvinyl alcohol (PVA)-based proton conducting polymer electrolytes have been prepared by the solution cast technique. The conductivity is observed to increase from 10 −9 to 10 −4 S cm −1 as a result of orthophosphoric acid (H 3 PO 4 ) addition. The plot of conductivity vs temperature shows that a phase transition occurred at 343 K in the sample PVA-33 wt% H 3 PO 4 . The β-relaxation peak is observed at 313 K. The glass transition temperature of PVA-33 wt% H 3 PO 4 is 343 K. Orthophosphoric acid seems to play a dual role, i.e., as a proton source and as a plasticizer. The ac conductivity σ ac = Aω s was also calculated in the temperature range from 303 to 353 K. The conduction mechanism was inferred by plotting the graph of s vs T from which the conduction mechanism for sample PVA-17 wt% H 3 PO 4 was inferred to occur by way of the overlapping large polaron tunneling (OLPT) model and the conduction mechanism for the sample PVA-33 wt% H 3 PO 4 by way of the correlated barrier height (CBH) model.

Section: Resultsmentioning

confidence: 68%

Dielectric and conduction mechanism studies of PVA-orthophosphoric acid polymer electrolyte

Kufian

Majid

Arof

2007

“…Conductivity as high as 10 −2 S/cm has been reported for these gel-type membranes at room temperature [18]. Other ion-conducting polymer electrolytes have also been studied for various applications [19,20]. In the present work, the dielectric relaxation is used to probe the molecular mobility of the amorphous phase of the PVOH-CF 3 COONH 4 polymer system near the glass transition region.…”

Section: Introductionmentioning

confidence: 97%

Dielectric relaxation and dc conductivity on the PVOH-CF3COONH4 polymer system

Castillo

Chacón

Castillo

et al. 2009

In the present paper, the ionic conductivity and the dielectric relaxation properties on the poly(vinyl alcohol)-CF 3 COONH 4 polymer system have been investigated by means of impedance spectroscopy measurements over wide ranges of frequencies and temperatures. The electrolyte samples were prepared by solution casting technique. The temperature dependence of the sample's conductivity was modeled by Arrhenius and Vogel-Tammann-Fulcher (VTF) equations. The highest conductivity of the electrolyte of 3.41×10 −3 ( cm) −1 was obtained at 423 K. For these polymer system two relaxation processes are revealed in the frequency range and temperature interval of the measurements. One is the glass transition relaxation (α-relaxation) of the amorphous region at about 353 K and the other is the relaxation associated with the crystalline region at about 423 K. Dielectric relaxation has been studied using the complex electric modulus formalism. It has been observed that the conductivity relaxation in this polymer system is highly nonexponential. From the electric modulus formalism, it is concluded that the electrical relaxation mechanism is independent of temperature for the two relaxation processes, but is dependent on composition.

“…It has a carbon chain backbone with hydroxyl groups attached to methane carbons. These OH-groups can be a source of hydrogen bonding and hence assist the formation of polymer electrolytes [1][2][3][4][5][6]. Recent studies have dominated lithium ion conducting systems for their potential use in solid-state batteries with high cell voltages and energy densities.…”

Section: Introductionmentioning

confidence: 99%

Structural and electrical properties of pure and H2SO4 doped (PVA)0.7(NaI)0.3 solid polymer electrolyte

Badr

Sheha

Bayomi

et al. 2009

Solid polymer electrolytes (SPE) based on poly-(vinyl alcohol) (PVA) 0.7 and sodium iodide (NaI) 0.3 complexed with sulfuric acid (SA) at different concentrations were prepared using solution casting technique. The structural properties of these electrolyte films were examined by X-ray diffraction (XRD) studies. The XRD data revealed that sulfuric acid disrupt the semi-crystalline nature of (PVA) 0.7 (NaI) 0.3 and convert it into an amorphous phase. The proton conductivity and impedance of the electrolyte were studied with changing sulfuric acid concentration from 0 to 5.1 mol/liter (M). The highest conductivity of (PVA) 0.7 (NaI) 0.3 matrix at room temperature was 10 −5 S cm −1 and this increased to 10 −3 S cm −1 with doping by 5.1 M sulfuric acid. The electrical conductivity (σ) and dielectric permittivity (ε′) of the solid polymer electrolyte in frequency range (500 Hz-1 MHz) and temperature range (300-400) K were carried out. The electrolyte with the highest electrical conductivity was used in the fabrication of a sodium battery with the configuration Na/SPE/MnO 2 . The fabricated cells give open circuit voltage of 3.34 V and have an internal resistance of 4.5 kΩ.