Lithium Conducting Solid Polymer Electrolytes Based on Polyacrylonitrile Copolymers: Ion Solvation and Transport Properties

The systems poly(butadiene-co-acrylonitrile) (PBAN) - lithium salts have been studied by means of X-ray and IR spectroscopy, optical microscopy and ac- and dc-conductivity measurements. X-ray and microscopy studies have confirmed that PBAN dissolves LiClO(4) up to [CN]/[Li] approximate to 2:1. IR spectra of the samples with LiAsF(6), LiCF(3)SO(3) and LiClO(4) have indicated the coordination between Li(+) and the polar CN groups of PBAN. So, PBAN was found to be a suitable polymer matrix for SPE. The polymer films exhibited predominant ionic conductivity. Measurements of conductivity and Li transport numbers versus temperature over a wide range of salt concentrations revealed the existence of two concentration regions (within the limits of salt solubility) corresponding to liquid-like and glass-like ion transport mechanisms. New solid polymer electrolyte with lithium single-ion conductivity of 10(-3) S cm(-1) at 25 - 95 degrees C was obtained.