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

Abstract

AbstractInorganic/organic dielectric composites are very attractive for high energy density electrostatic capacitors. Usually, linear dielectric and ferroelectric materials are chosen as inorganic fillers to improve energy storage performance. Antiferroelectric (AFE) materials, especially single‐crystalline AFE oxides, have relatively high efficiency and higher density than linear dielectrics or ferroelectrics. However, adding single‐crystalline AFE oxides into polymers to construct composite with improved energy storage performance remains elusive. In this study, high‐quality freestanding single‐crystalline PbZrO3 membranes are obtained by a water‐soluble sacrificial layer method. They exhibit classic AFE behavior and then 2D–2D type PbZrO3/PVDF composites with the different film thicknesses of PbZrO3 (0.1‐0.4 µm) is constructed. Their dielectric properties and polarization response improve significantly as compared to pure PVDF and are optimized in the PbZrO3(0.3 µm)/PVDF composite. Consequently, a record‐high energy density of 43.3 J cm−3 is achieved at a large breakdown strength of 750 MV m−1. Phase‐field simulation indicates that inserting PbZrO3 membranes effectively reduces the breakdown path. Single‐crystalline AFE oxide membranes will be useful fillers for composite‐based high‐power capacitors.