In recent years, PbZrO₃ (PZO) films have become favorable electric storage materials due to the unique electric field-induced phase transition behavior, but the severe hysteresis effect leads to low energy storage density and efficiency. In this work, inserting Al₂O₃ (AO) insulation nanolayers is proposed to tune the polarization behavior of flexible PZO films, anticipating optimization of energy storage performance. The results show that the thickness of the AO nanolayers has a deep influence on the polarization behavior of the PZO films, and PZO/AO/PZO (PAP) sandwiched films with 8 nm AO interlayer deliver relaxor ferroelectric-like polarization instead of antiferroelectric counterpart. To further utilize the AO nanolayers as top/bottom layers, the linear-like polarization and the highest breakdown strength are achieved in the AO/PZO/AO/PZO/AO (APAPA8) multilayer films, leading to both high discharged energy storage density of 35.2 J/cm³ and efficiency of 92.9%, as well as excellent fatigue and bending endurance, good temperatures, and frequency stability. The tunable polarization induced by growing the AO nanolayers makes antiferroelectric PZO films have great potential to be used as energy storage dielectrics.

Commercial biaxially oriented polypropylene (BOPP) film capacitors have been widely applied in the fields of electrical and electronic engineering. However, due to the sharp increase in electrical conduction loss as the temperature rises, the energy storage performance of BOPP films seriously degrades at elevated temperatures. In this study, the grafting modification method is facile and suitable for large-scale industrial manufacturing and has been proposed to increase the high-temperature energy storage performance of commercial BOPP films for the first time. Specifically, acrylic acid (AA) as a polar organic molecular is used to graft onto the surface of commercial BOPP films by using ultraviolet irradiation (abbreviated as BOPP−AA). The results demonstrate that the AA grafting modification not only slightly increases the dielectric constant, but also significantly reduces the leakage current density at high-temperature, greatly improving the high-temperature energy storage performance. The modified BOPP−AA films display a discharged energy density of 1.32 J/cm³ with an efficiency of >90% at 370 kV/mm and 125 °C, which is 474% higher than that of the pristine BOPP films. This work manifests that utilizing ultraviolet grafting modification is a very efficient way to improve the high-temperature energy storage performance of commercial BOPP films as well as provides a hitherto unexplored opportunity for large-scalable production applications.