Preparation of monodispersed ZrO2 nanoparticles and their applications inpoly[(vinylidene fluoride)-co-hexafluoropropylene]-based composite polymer electrolytes

To improve the electrochemical performance of pure poly[(vinylidene fluoride)-co-hexafluoropropylene] (P(VDF-HFP))-based gel polymer electrolytes, different amounts of monodispersed ZrO2 nanoparticles were introduced to fabricate P(VDF-HFP)/ZrO2 composite polymer electrolytes (CPEs) using the phase inversion method and activated processes, in which the monodispersed ZrO2 nanoparticles were synthesized by an easy route without any chelating agents or surfactants, and confirmed using scanning electron microscopy, particle size distribution measurement and X-ray diffraction. The characterization results show that the as-fabricated CPE membranes present not only an abundant porous structure, but also an improved mechanical strength. In particular, sample CPE-5 presents the best properties when the doped content of the monodispersed ZrO2 nanoparticles reaches 5wt% in the polymer matrix, in which the liquid uptake and ionic conductivity at room temperature are about 192.4% and 3.926 mS cm(-1), and the electrochemical working window and thermal decomposition temperature can increase to 5.1V and 420 degrees C, respectively. Moreover, an assembled LiCoO2/CPE-5/Li coin cell can deliver excellent rate and cycling performance, in which the discharge specific capacity of the cell can show about 83.95% capacity retention at 2.0 C after 85cycles. (c) 2018 Society of Chemical Industry