| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1297303 | Solid State Ionics | 2011 | 8 Pages |
The polyethylene oxide (PEO) based lithium ion conducting polymer electrolytes complexed with lithium trifluoromethanesulfonate (LiCF3SO3 or LiTf) plasticized with an ionic liquid 1-ethyl 3-methyl imidazolium trifluoromethanesulfonate (EMITf) have been reported. Morphological, spectroscopic, thermal and electrochemical investigations demonstrate promising characteristics of the polymer films, suitable as electrolyte in various energy storage/conversion devices. Significant structural changes have been observed in the polymer electrolyte due to the ionic liquid addition, investigated by X-ray diffraction (XRD) and optical microscopy. The ion-polymer interaction, particularly the interaction of imidazolium cation with PEO chains, has been evidenced by IR and Raman spectroscopic studies. The optimized composition of the polymer electrolyte i.e. PEO25.LiTf + 40 wt.% EMITf offer room temperature ionic conductivity of ~ 3 × 10− 4 S cm− 1 with wide electrochemical stability window and excellent thermal stability. The ‘σ versus 1/T’ curves show apparent Arrhenius behavior below and above melting temperature. The ionic conductivity has been observed due to Li+ ions, as confirmed from 7Li-NMR studies, though the component ions of ionic liquid and anions also contribute significantly to the overall conductivity.
► Effect of ionic liquid addition on the PEO-based electrolyte properties is reported. ► PEO-LiCF3SO3-IL films are thermally and electrochemically stable electrolytes. ► FTIR and Raman studies confirm the ion-polymer, particularly EMI+-PEO interaction. ► Material offers Li+ and EMI+ transport along with substantial contribution of anions.
