Ultrahigh Energy Storage Capacitors Based on Freestanding Single-Crystalline Antiferroelectric Membrane/PVDF Composites

摘要

Inorganic/organic dielectric composites are very attractive for high energydensity electrostatic capacitors. Usually, linear dielectric and ferroelectricmaterials are chosen as inorganic fillers to improve energy storageperformance. Antiferroelectric (AFE) materials, especially single-crystallineAFE oxides, have relatively high efficiency and higher density than lineardielectrics or ferroelectrics. However, adding single-crystalline AFE oxides intopolymers to construct composite with improved energy storage performanceremains elusive. In this study, high-quality freestanding single-crystallinePbZrO_3 membranes are obtained by a water-soluble sacrificial layer method.They exhibit classic AFE behavior and then 2D–2D type PbZrO_3/PVDFcomposites with the different film thicknesses of PbZrO_3 (0.1-0.4 μm) isconstructed. Their dielectric properties and polarization response improvesignificantly as compared to pure PVDF and are optimized in thePbZrO_3(0.3 μm)/PVDF composite. Consequently, a record-high energy densityof 43.3 J cm~（?3） is achieved at a large breakdown strength of 750 MV m?1.Phase-field simulation indicates that inserting PbZrO_3 membranes effectivelyreduces the breakdown path. Single-crystalline AFE oxide membranes will beuseful fillers for composite-based high-power capacitors.