Enhanced breakdown strength and energy storage of PVDF-based dielectric composites by incorporating exfoliated mica nanosheets

The development of flexible and high-performance dielectric materials is of critical importance in energy storage devices. Since energy density of a dielectric capacitor is determined by the dielectric constant and breakdown strength, in this work, a simple and effective way is provided to increase the energy storage density of polymer matrix dielectric film via adding exfoliated mica nanosheets. Few-layered mica nanosheets were successfully exfoliated by a facile one-step method and incorporated with Poly(vinylidene fluoride) (PVDF) matrix. The mica nanosheets could act as the insulating barriers, which help to increase the breakdown strength of the PVDF/mica composites. The maximum discharged energy density of the prepared composite film was 7.93 J cm(-3) at 450 MV m(-1) with only 5 vol% of mica nanosheets, which is about three times higher than pure PVDF. This study introduced an economic and effective approach to get flexible and high energy density polymer composite films and broadened the application of mica. POLYM. COMPOS., 2018. (c) 2018 Society of Plastics Engineers