Enhanced energy storage performance of poly(vinylidene fluoride)-based polymer blends via post-treatments

Polymer-based dielectric composite films with large energy density are urgently demanded for various applications. Compared with the ones with inorganic fillers, polymer blends exhibit the advantage of mechanical matching as well as the interfacial compatibility. Herein, poly(vinylidene fluoride) (PVDF) composite films with various volume fractions of methyl methacrylate-butadiene-styrene (MBS) were prepared via the solution casting. The maximum energy density of 6.4 J/cm3 at 390 MV/m was obtained by optimizing the content of 12 vol% MBS in MBS/PVDF composite films. The energy density of the optimized composite films was further improved with the help of post-treatments including quenching and/or hot-pressing. At last, the composite films display the enhanced energy density of 8.7 J/cm3 at 500 MV/m with the efficiency of 67.4% via the comprehensive post-treatments. This work provides a paradigm to improve the energy storage performance of PVDF-based composite films for dielectric electrostatic capacitors.