Molecular design of inorganic-organic hybrid polyelectrolytes to enhance lithium ion conductivity

Three types of inorganic-organic hybrid polymers containing the ate complex structure (e.g. aluminate, berate) were prepared as lithium ion conducting polymer electrolytes. The relationship between polymer structure and ionic conductivity was discussed from which it was shown that the concepts of molecular design used were very important. Ionic conductivity was enhanced by the introduction of Lewis acid groups, which reduced the charge density on the ate complex and weakened ion pairing between the lithium ion and the immobilized anion. Ionic conductivity was found to be dependent on the length and structure of the oligoether chain. In addition, introduction of bulky groups onto the polymer backbone in the region of the oligoether chain restricted the mobility of the latter. (C) 2000 Elsevier Science Ltd. All rights reserved.