PEO BASED NANO-COMPOSITE SOLID POLYMER ELECTROLYTES FOR SOLID STATE IONIC DEVICES

摘要

Although Polyethylene Oxide (PEO) based solid polymer electrolytes have many advantages to be used as electrolyte membranes in lithium rechargeable batteries and other solid state ionic devices, their low ambient temperature conductivity has been a major drawback that limits these practical applications. Recent research efforts to improve the ambient temperature conductivity in PEO based solid polymer electrolytes have been directed towards the incorporation of ultra-fine nano-sized particles of ceramic fillers such as Al2O3, 冏-LiAlO2, SiO2 and TiO2 into the polymer electrolyte. In these PEO based nano-composite polymer electrolytes, conductivity enhancements of up to two orders of magnitude have been achieved. Thermal, electrical conductivity and dielectric relaxation measurements performed on several nano-composite polymer electrolyte systems have shown that the degree of enhancement depends primarily on the grain size and the specific surface area of grains.. In this paper, results of several PEO based, nano-composite polymer electrolyte systems are discussed as representative examples. It is suggested that the conductivity enhancement due to the nano ceramic filler is due to the creation of additional sites and favourable conduction pathways for ionic transport through Lewis acid-base type interactions between the filler surface groups (H/OH) and the ionic species. 1.