High-performance gel polymer electrolytes derived from PAN-POSS/PVDF composite membranes with ionic liquid for lithium ion batteries

The gel polymer electrolytes (GPEs) with poly(acrylonitrile-polyhedral oligomeric silsesquioxane)/poly(vinylidene fluoride) (PAN-POSS/PVDF) blends as free-standing porous membrane and ionic liquid (IL) as absorption substance were successfully prepared. By tuning the content of PAN-POSS, the porosity and absorptivity of the blended membranes could be regulated. Due to the higher porosity and absorptivity, the ionic conductivity of GPEs with 15 wt% PAN-POSS reaches to 1.91 × 10−3 S cm−1 at 20 oC. Meanwhile, the electrolytes also show excellent mechanical properties, thermal stability, and fire resistance. More importantly, the high electrochemical window of 4.6 V (vs. Li/Li+) has been acquired and the testing cells with Li metal anode and LiFePO4 cathode show a tolerable rate performance. Such prepared GPEs are expected to be applied to lithium batteries with high safety and electrochemical performance.