Core–shell structured SiO2 nanoparticles with controlled morphology were synthesized and used as functional fillers in Li+-conducting composite polymer electrolytes for lithium-ion polymer batteries. The composite polymer electrolytes prepared with poly(vinylidene fluoride-co-hexafluoropropylene) and core–shell SiO2(Li+) nanoparticles exhibited high ionic conductivity, good mechanical strength and favorable interfacial characteristics. Tests run on carbon/LiNi1/3Co1/3Mn1/3O2 cells with composite polymer electrolyte containing optimized SiO2(Li+) nanoparticles yielded excellent results in terms of capacity retention (95% after 100 cycles) and rate capability (167 mA h g−1 at 5 C rate).
