Compressible Polymer Composites with Enhanced Dielectric Temperature Stability

Abstract

AbstractHigh‐dielectric‐constant polymer composites have broad application prospects in flexible electronics and electrostatic energy storage capacitors. Substantial enhancement in dielectric constants (εr) of polymer composites so far can only be obtained at a high loading of nanofillers, resulting in high dielectric loss and high elastic modulus of polymer composites. Addressing the polarization shielding and the consequent polarization discontinuity at polymer/filler interfaces has been a long‐standing challenge to achieve flexible polymer composite with high εr. Herein, a polymer composite with interconnected BaTiO3 (BT) ceramic scaffold is proposed and demonstrated, which exhibits a high εr of ≈210 at a low BT volume fraction of ≈18 vol%, approaching the upper limit predicted by the parallel model. By incorporating relaxor Ba(ZrxTi1−x)O3 phase in BT scaffold, dielectric temperature stability is further achieved with Δεr below ±10% within a broad temperature range (25–140 °C). Moreover, the dielectric performances remain stable under a compressive strain of up to 80%. This work provides a facile approach to construct large‐scale polymer composites with robust dielectric performance against changes in thermal and mechanical conditions, which are promising for high‐temperature applications in flexible electronics.