Characterization of Ionic Conducting Cross-linked Polyether Electrolytes

An appropriate amount of toluene 2,4-diisocyanate （TDI） was added into polyether（[（CH2CH2O） 13CH2O]n）/Li salt electrolyte to form a cross-linked network, with improving the film processability and thermal stability. The relation between the structure and ionic conductive properties of the cross-lined polyether electrolytes was investigated by means of Fourier transform infra-red spectroscopy （FTIR）, differential scanning calorimetry （DSC）, mechanical property and AC impedance spectroscopy. The electrolytes system is found to have two glass transitions, and it is found that the two Tgs increase with increasing salt concentration. At the same Li salt concentration, the conductivity of cross-linked polyether/LiN（CF3SO2）2 complex system is higher than that of LiClO4. At EO/Li=25∶1（mol ratio）, the former conductivity changes with temperature, while the later coincids with Arrhenius formula （σ=Ae -Ea/RT）. The cross-linked polyether/LiN（CF3SO2）2 electrolyte exhibits the maximum σ=10 -4.75S/cm at 30 ℃.