Enhanced energy storage efficiency in PVDF based composite films using MnO2 nano-fillers

Abstract

The flexible energy storage film based on PVDF matrix has very extensive application. The electrical properties of PVDF composite films doped by nanometer MnO2 was studied in this research, and the influences of MnO2 content on dielectric constant, breakdown strength and energy storage properties were systematic investigated. The results indicated that using MnO2 as fillers is an effective approach to improve the dielectric constant and breakdown strength of PVDF matrix composites. The dielectric constant is 18.1 and the breakdown electric field is 100 kV/mm when the content of MnO2 is 10 wt%. In addition, both large energy storage density (1.67 J/cm3) and high energy storage efficiency (81.9%) are obtained in composite film with 10 wt% MnO2. The enhancement of dielectric constant and energy storage efficiency are due to the ionic polarization of MnO2 under applied electric field. Moreover, the effect of MnO2 on electron trapping improves the breakdown strength and energy storage density of MnO2/PVDF composite films. This work provides a feasible route for designing flexible composites with excellent energy storage performance.