MOF-silsesquioxane synergistic modified hybrid porous membrane for high-performance and high-safety lithium battery

As an emerging alternative separator, electrospun PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) has been widely studied in lithium battery over the years. However, some shortcomings of PVDF-HFP have limited its further application, such as, poor thermal stability, mechanical and electrochemistry properties. In this work, the cage-like silsesquioxanes (CSQ) and metal–organic-framework (MOF) were chemically bound to PVDF-HFP, and a modified hybrid fibrous membrane with hierarchical pore was fabricated. These hybrid groups were successfully introduced into the backbone of PVDF-HFP, which was not only demonstrated by characterization of their chemical structures, and also demonstrated by morphologies and elemental mass spectrometry with the help of scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Due to the incorporation of these hybrid groups, the membrane exhibited high thermal stabilities and good flame-retardant performance, and could also play an important role in regulating and improving the migration property of lithium ions and interface performance between electrolyte and electrodes during battery charging/discharging process.