Studies on structural thermal and electrical transport properties of ionic liquid based polymer electrolytes

Abstract

Solid electrolytes or fast ion conductors are the materials which exhibit high ionic newlineconductivity, typically in the range (10-6 10-3 S.cm-1) and negligible electronic newlineconductivity (lt 10-4). These solid electrolytes are characterized by low activation energy newlinefor ion transport. Due to their potential application these materials are very useful in newlinesolid state electrochemical devices such as batteries, super capacitors, fuel cells, sensors, newlineactuators and electrochromic display devices. Solid State Ionics is a fast emerging field newlineof science and technology dealing with such materials and devices based on ionic motion newlinein solids. Conventional ionic solids like alkali halides (NaCl, KCl etc.) have very low newlineroom temperature ionic conductivity (lt10-12 S.cm-1) but their conductivities could be newlineincreased, though not much, by introducing impurities or defects. Historically, some newlinesilver halides like AgI, Ag2S, Ag2Te, Ag3Si, etc. were reported to show high newlineconductivity at high temperatures after transition to a phase whose structure is conducive newlineto ion transport. However, real breakthrough came in 1967 when two groups of materials newlineviz., MAg4I5 (where M = Rb, K, NH4 etc.) and and#946;-alumina were reported to show high newlineionic conductivity at high temperatures which showed promise for applications in solid newlinestate battery and many other solid state electrochemical devices. Immediately, intensive newlinesearch for many more materials with high ionic conductivity started which resulted in the newlinedevelopment of such materials showing good ionic conductivity for Na+, Li+, K+, H+, O2- newline, and F- ions. On the basis of these principal charge carriers the discovered materials newlinewere mostly developed in the form of crystalline/or polycrystalline, ions conducting newlineglasses, composites/or ceramic solids, gel electrolytes, polymer electrolytes, plasticized polymer electrolytes, etc. newline