Multi-synergy effects-induced high electric breakdown field in polymer composites via 0D/2D design

Constructing polymer composites containing zero-dimensional (0D) nanoparticles and two-dimensional (2D) lamellae is a simple and effective strategy to obtain high energy storage performance. Although the hexagonal boron nitride nanosheets (BNNSs) are widely used in energy storage areas, the low yield hinders their application. This work employed Al 2 O 3 (AO) nanoparticles and thick hexagonal boron nitride (h-BN) lamellae to fabricate poly (vinylidene fluoride) (PVDF)-based films. An expected synergy effect on the breakdown strength ( E b ) is achieved as the filler content and ratio change. A high E b (450 MV/m), which is 110 MV/m higher than the pure PVDF (340 MV/m), was acquired with a small loading (4 wt.%). The analysis suggests multiple synergy effects between AO and h-BN on leakage current, crystallinity, melting point, and Young’s modulus contribute to the high E b . However, a desirable low leakage current is an indispensable part of these properties. In addition to this, the mechanisms behind these synergy effects were discussed. A comprehensive comparison indirectly proves that the AO particles can increase the dispersibility of h-BN lamellae. Besides, the dielectric behavior and energy storage performance were comprehensively examined.