Solid Polymer Blend Electrolytes Research Articles

Ionic conductivity and electrochemical properties of cross-linked solid polymer electrolyte using star-shaped siloxane acrylate

Abstract A star-shaped siloxane acrylate with a different number of repeating units of oligo(ethylene oxide) (EO) was synthesized as a cross-linker of solid polymer electrolytes. The cross-linked solid polymer electrolytes blended with the ionic conducting plasticizers, such as low molecular weight poly(ethylene oxide)dimethyl ether (PEGDME) were prepared by the in situ thermal curing of the star-shaped siloxane acrylate. Different morphologies of the cross-linked polymer electrolytes were observed according to the number of repeating units of EO ( n ) in the cross-linker. A micro-phase separated solid polymer electrolyte was obtained when the n of cross-linker was 1. When the n of cross-linker was larger than 1, homogeneously blended solid polymer electrolytes were prepared. The ionic conductivity was measured to be 6.3 to 7.8 × 10 −4 S cm −1 with 80 wt.% PEGDME at 30 °C. The ionic conductivity of the micro-phase separated solid polymer electrolyte was slightly higher than that of the homogeneously blended solid polymer electrolyte. The electrochemical stability window of the resulting solid polymer electrolyte could be extended to up to 4.8 V versus Li/Li + reference electrode.

Electrical conductivity studies on PVA/PVP-KOH alkaline solid polymer blend electrolyte

A series of conducting thin-film solid electrolytes based on poly (vinyl alcohol)/ poly (vinyl pyrrolidone) (PVA/PVP) polymer blend was prepared by the solution casting technique. PVA and PVP were mixed in various weight percent ratios and dissolved in 20 ml of distilled water. The samples were analyzed by using impedance spectroscopy in the frequency range between 100 Hz and 1 MHz. The PVA/PVP system with a composition of 80% PVA and 20 wt.% PVP exhibits the highest conductivity of (2.2±1.4) × 10−7 Scm−1. The highest conducting PVA/PVP blend was then further studied by adding different amounts of potassium hydroxide (KOH) ionic dopant. Water has been used as solvent to prepare PVA/PVP-KOH based alkaline solid polymer blend electrolyte films. The conductivity was enhanced to (1.5 ± 1.1) × 10−4 Scm−1 when 40 wt.% KOH was added.

Structural and transport characteristics of polyethylene oxide/phenolic resin blend solid polymer electrolytes

AbstractDetails on the structure and transport characteristics of the solid polymer electrolyte polyethylene oxide (PEO)/lithium salt (LiClO4) modified by novolac phenolic resin are presented here. From IR spectra it could be concluded that complex formation occurred through multiple interactions between the ether oxygen of PEO–lithium, phenolic lithium, and the phenolic ether oxygen of PEO. The free hydroxyl band in phenolic reflected that phenolic closely interacted with both the PEO polymer and ionic salt. With increasing salt content in PEO, the vibration band corresponding to the ClO anion (∼623 cm−1) displayed growth of a shoulder at ∼635 cm−1, suggesting the formation of Li+…ClO4− ion pairing. However, in the presence of phenolic, ion‐pairing formation was effectively suppressed, which suggested that the phenolic moiety facilitated a greater degree of LiClO4 salt dissociation. Activation energy analysis revealed two conducting pathways: one through the amorphous PEO and the other through the PEO/phenolic amorphous matrix. The high ion conductivity originated from effective salt dissociation and the establishment of a new conduction network formed by PEO and phenolic. Furthermore, the structural modification also extended the thermal stability and mechanical strength of the solid polymer electrolyte composite. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3866–3875, 2004

Characterization of PVA–PVdF based solid polymer blend electrolytes

In order to optimize the blend composition of PVA–PVdF–LiClO 4 polymer electrolytes, flexible films are prepared using solvent casting technique. The complex formation has been ascertained by XRD and FTIR analyses. The AC conductivity studies are carried out to evaluate the ambient temperature conductivity of the polymer electrolytes. The maximum conductivity value 3.0364×10 −5 S/cm has been observed for PVA (67.5)–PVdF (22.5)–LiClO 4 (10 wt%) system. Thermal stability of the film exhibiting maximum conductivity is studied and the results are discussed.

Investigations on the effect of various plasticizers in PVA–PMMA solid polymer blend electrolytes

Solid polymer electrolyte films containing poly(vinyl alcohol) (PVA)/PMMA–LiBF 4–X (X=EC, PC, DEC, GBL) were prepared by solvent casting technique. Complexation of the prepared electrolytes is studied by XRD, FTIR analyses. Ionic conductivities of the electrolytes have been determined by ac impedance studies in the temperature range 302–373 K. The temperature-dependent ionic conductivity plots seem to obey the VTF relation. Dielectric relaxation studies of the polymer electrolyte have been undertaken and the results are discussed. Thermal stability of the prepared electrolytes has been examined using TG/DTA analysis. Cyclic voltammetry has been performed for the electrolyte films to study their cyclability and reversibility. The ionic transport in the polymer electrolytes has been discussed on the basis of free volume theory. The maximum ionic conductivity (1.2886×10 −3 S/cm) has been observed for EC-based complex because of the higher dielectric constant among the other plasticizers.