X-Ray Diffraction and Vibrational Spectroscopic Studies on PAN-LiTFSI Polymer Electrolytes

Polyacrylonitrile(PAN)‐lithium bis(trifluoromethane sulfone)imide (LiTFSI) complex has been investigated by X‐ray diffraction (XRD) and vibrational spectroscopy. Two kinds of amorphous complexes are found in the salt‐in‐polymer and polymer‐in‐salt regime, respectively. Phase transition is observed by XRD as the content of lithium salt increases from to . It is also evidenced by Fourier Transform infrared (FTIR) and Raman spectroscopic studies. Interactions between the ion and host polymer are clarified by comparing the spectral evolution of the −C≡N group before and after LiTFSI was complexed with PAN. However, the LiTFSI addition has no obvious influence on the group of PAN, evidently different from that observed with PEO. ions coordinate also with O and/or N of anions, probed by the spectral changes of ‐SNS and groups. © 2000 The Electrochemical Society. All rights reserved.