INFRARED SPECTROSCOPIC STUDY OF THE INTERACTION BETWEEN LITHIUM SALT LICLO4 AND THE PLASTICIZER ETHYLENE CARBONATE IN THE POLYACRYLONITRILE-BASED ELECTROLYTE

The infrared (IR) spectra of ethylene carbonate (EC) containing differ ent contents of lithium perchlorate (LiClO4) have been measured and an alyzed. It is found that, with the increase of the LiClO4 content in t he solution, both the vibrational frequencies and the relative intensi ties of the bands related to the ring structure and to the C=O group o f EC molecule are changed. The data have shown that there is a rather strong interaction between the Li+ ion and the EC molecule. The intera ctions between the Li+ ions and the EC molecules mainly occur on the C =O group of the molcules. In the meantime, the structure of the ClO4- anion is also affected by the EC molecules, forming solvent-shared ion pairs, Li+-EC-ClO4-.