24 research outputs found
Thermal and Conductivity Studies of VO2+ Doped Methacrylic Acid - Ethyl Acrylate (MAA:EA) Copolymer Films
Structural and ionic conductivity studies on proton conducting polymer electrolyte based on polyvinyl alcohol
Sodium-ion-conducting solid polymer electrolyte: temperature-dependent ionic parameters and solid-state polymer battery fabrication
Mechanism of ion transport in YSZ-dispersed polymer nanocomposite films: an analysis by vibrational spectroscopy approach
Solvent-free nanocomposite proton-conducting membranes composed of cesium salt of phosphotungstic acid doped PVDF–CTFE/PEO blend
Role of salt concentration on conductivity optimization and structural phase separation in a solid polymer electrolyte based on PMMA-LiClO4
Ionic conductivity in crystalline polymer electrolytes
Polymer electrolytes are the subject of intensive study, in part because of their potential use as the electrolyte in all-solid-state rechargeable lithium batteries(1). These materials are formed by dissolving a salt (for example LiI) in a solid host polymer such as poly(ethylene oxide) (refs 2-6), and may be prepared as both crystalline and amorphous phases. Conductivity in polymer electrolytes has long been viewed as confined to the amorphous phase above the glass transition temperature, T-g, where polymer chain motion creates a dynamic, disordered environment that plays a critical role in facilitating ion transport(2,3,7-9). Here we show that, in contrast to this prevailing view, ionic conductivity in the static, ordered environment of the crystalline phase can be greater than that in the equivalent amorphous material above T-g. Moreover, we demonstrate that ion transport in crystalline polymer electrolytes can be dominated by the cations, whereas both ions are generally mobile in the amorphous phase(10). Restriction of mobility to the lithium cation is advantageous for battery applications. The realization that order can promote ion transport in polymers is interesting in the context of electronically conducting polymers, where crystallinity favours electron transport(11,12).</p