Influence of salt content on polymer dissolution and ionic association in polymer electrolyte

Polymer electrolytes composed of polyacrylonitrile, propylene carbonate (PC), and lithium bis(trifluoromethane sulfone imide) (LiTFSI, LiN(CF3SO2)(2)) have been prepared and studied by Raman spectroscopy. The polymer cannot be dissolved in PC before all the PC molecules are associated with LiTFSI. As long as the polymer is dissolved in PC, the microstructures related to PC do not vary with the salt content, while the interaction between the Li+ ion and the polymer in the polymer electrolyte is striking. (C) 2001 The Electrochemical Society.