AC conductivity studies of polyethylene oxide-garnet-type Li7La3Zr2O12 hybrid composite solid polymer electrolyte films

摘要: Abstract We have investigated both AC dielectric permittivity and ionic conductivity of hybrid composite solid polymer electrolyte (CSPE) films (~100 μm) comprised sub-micron sized aluminum substituted cubic Li7La3Zr2O12 (LLZO) particles dispersed in polyethylene oxide-LiClO4 (PEO-LiClO4) matrix with [EO]:[Li] = 15:1. Homogeneous CSPE 50 wt% LLZO (PEO-LLZO-LiClO4) exhibit good flexibility mechanical robustness up to 120 °C. The electrochemical potential stability window measured for these was ~5.2 V vs. Li+/Li. complex were determined using the electrical impedance spectra range 1 Hz 300 kHz found be heavily affected by electrode polarization low frequency region. analyzed data an expression that generalizes power-law dependence taking into account effect involving segmental relaxation times its description. This describes very well observed behavior entire obtained from fitting experimental indicate a strong coupling between motion dynamics. Further, temperature dependent follows Vogel-Tammann-Fulcher (VTF) implying close correlation electrolytes. VTF model yields activation energy 0.32 eV PEO-LiClO4 film, 0.07 eV PEO-LLZO-LiClO4 consistent enhancement two orders magnitude at 30 °C upon addition particles.