Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1293521 | Solid State Ionics | 2015 | 12 Pages |
•PEO-based electrolytes were obtained and characterized by DSC, FTIR and EIS.•Crystallinity decreases as [O]:[M] decreases; single Tg were found for all samples.•Li+ complexation by both PEO and PVPh-HEM chains•σ values reached 10− 5 Ω− 1 cm− 1 for T > 40 °C; stability up to 3.5 V.•Ea between15.4 kJ mol− 1and 6.2 kJ mol− 1, depending on [O]:[M]
Solid electrolytes based on poly(ethylene oxide)/poly(4-vinyl phenol-co-2-hydroxyethyl methacrylate) (PVPh-HEM) blends and LiClO4 were obtained and characterized by differential scanning calorimetry (DSC), infrared vibrational spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). DSC curves showed a progressive decrease of crystallinity as the [O]:[M] ratio decreases in the polymer matrices and one glass transition temperature (Tg) for all the samples, indicating that the original miscibility of the blend is maintained in the presence of LiClO4. Analysis of the vibrational mode ν(COC) from the PEO chain suggests the complexation of Li+ with the ether binding sites and, from a decomposition treatment employed to the vibrational spectra, the spectroscopic fractions of modes ν(CO) and ν(ClO4) were analyzed. The DSC and FTIR results allowed the elaboration of a molecular model to describe the cation–polymer interactions in the solid. From the impedance spectra, conductivity (σ) values were obtained as a function of [O]:[M] ratio and PVPh-HEM concentration in the polymer matrices. The σ values reached 10− 5 Ω− 1 cm− 1 for temperatures higher than 40 °C and the electrolytes exhibited stability up to 3.5 V.