PEO‐PVP‐NaIO₄ Ion‐Conducting Polymer Electrolyte: Inspection for Ionic Space Charge Polarization and Charge Trapping

Abstract

Ion‐conductive solid polymer electrolytes composed from blends of poly(ethylene oxide) (PEO) and poly(vinylpyrrolidone) (PVP), as complexed with the ionic compound sodium periodate (NaIO4), are inspected for the presence of electric charge trapping (CT) and ionic space charge polarization (SCP) under static electric field. Thin films (110 μm‐thick) of these materials are produced at a ratio of the polymers PEO:PVP = 70:30 wt%, the concentration of NaIO4 is 5, 7.5, or 10 wt%. The electrical current at room temperature, as well as the charging/discharging in the films are studied as depending on applied voltage and time. At a detectable level, no SCP and CT processes in PEO‐PVP‐NaIO4 are evidenced, in contrast to identical experiments by PEO film under the same experimental conditions. The largely reduced SCP and CT are of importance for electrochemical applications of the considered ion‐conducting PEO‐PVP‐NaIO4 ion‐polymer coupled system.

Ion-Conducting Flexible Thin Films of Composites from Poly(ethylene oxide) and Nematic Liquid Crystals E8—Characterization by Impedance and Dielectric Relaxation Spectroscopy

“…In our case, the composite film composed of 70 wt.% PEO and 30 wt.% E8LC can be considered a 3D spongy membrane (network of the polymer matrix) in which nematic LCs permeate the pores of the polymer (LC molecules embedded in a porous network). The microscopic porosity of the studied composites (pores and microvoids, probably interconnected) was evidenced by scanning electron microscopy (SEM) studies [52]. The 'soft mode' dielectric relaxation is well established for polar nematic LCs, such as pentylcyanobiphenyl (5CB), filling micropores [51].…”

Ion-Conducting Composites of Polymers and Nematic Liquid Crystals

“…Such a “densifying and smoothing” structural effect for the host polymer and obtaining a more homogenized material are known to occur by blending of PEO with a suitable organic component plasticizer. In fact, this has been observed for 150 μm thick composite films produced by solution casting from PEO blended with the amorphous polymer poly­(vinylpyrrolidone) (PVP) at a weight fraction of 30 wt % . Thus, the SEM observations in Figure suggest that the material formed in the considered PNLCCs possesses a higher degree of amorphousness than the polymer PEO itself.…”

“…In fact, this has been observed for 150 μm thick composite films produced by solution casting from PEO blended with the amorphous polymer poly(vinylpyrrolidone) (PVP) at a weight fraction of 30 wt %. 23 Thus, the SEM observations in Figure 3 suggest that the material formed in the considered PNLCCs possesses a higher degree of amorphousness than the polymer PEO itself. In these structures inspected by SEM, one could not identify specific assemblies or aggregation forms, e.g., such as NLC molecular agglomerates whose formation may be promoted from cyanophenyl molecules of E8 LC being in a confined volume within the host polymer (confined in the nanoscale vicinity to the PEO functional groups).…”

Effect of new crystalline phase on the ionic conduction properties of sodium perchlorate salt doped carboxymethyl cellulose biopolymer electrolyte films

“…An increase in the area indicates the occurrence of dissociation of the ions (up to CP20) followed by saturation at higher dopant concentration indicates either the formation of ion-aggregates or saturation in salt-polymer complexation that has occurred due to non-availability of functional group (especially ether group) to dissociate the salt and will be discussed in the coming section. From the FTIR study, it is clear that interaction between the salt and the polymer has led to complex formation via intermolecular hydrogen bonding and Lewis acid-base interaction, and these two effects would result in the promotion of free ions due to the presence of polar group -O-, -H-and -C-H-, in the polymer chain that helps to dissociate the salt [19]. A noticeable change is brought about by hydrogen bonding for higher salt concentration rather than Lewis-acid base interaction, indicating the hydrogen bonding is strong enough to cause a prominent change in the IR spectra.…”