PEO-BASED COMPOSITE POLYMER ELECTROLYTES

Poly(ethylene oxide) (PEO)-based composite polymer electrolytes have b een widely studied during the last ten years. At present, systems, wit h room temperature conductivity up to 10(-4) ohm(-1) cm(-1) have been synthesized and tested in electrochemical devices like lithium-ion rec hargeable batteries. In this paper, we will chiefly focus on the exper imental work, whereas the theoretical models for ion transport will be only summarized. The systems are classified as 'blend-based' and 'mix ed-phase' composite electrolytes. We call blend-based systems those sy stems obtained from homogeneous solutions of two components in an appr opriate common solvent. Mixed-phase systems are inhomogeneous mixtures of polymer and inorganic or organic additives not dissolved in a comm on solvent. Effective Medium Theories (EMT) are useful for modelling t he conductivity behaviour in these composite electrolytes. (C) 1998 El sevier Science B.V. All rights reserved.