High Energy Density PVDF-Based Composites with Efficient Stripping of Boron Nitride Nanosheets

Bronnitride nanosheets (BNNS) have attracted considerable interest in preparing high energy density (Ue) polymer nanocomposites due to its intrinsic high breakdown strength and thermal conductivity. However, efficient fabrication of BNNSs remains a challenge due to the low yield and complex fabrication process, which limits their further wide applications in polymer-based dielectrics. In this study, effectively stripped thin layer BNNS were prepared with high yield by urea-assisted ball milling combined with ultrasonic thermal stripping. The results showed that BNNS not only achieved efficient stripping and good dispersion in liquid solutions, but also effectively increased the energy storage capacity of the PVDF-based composites, with the highest Ue (7.5 J cm−3 at 450 MV m−1) achieved in 8 wt% BNNS/PVDF composites.