Enhanced energy storage efficiency in PVDF based composite films using MnO_2 nano-fillers

摘要

The flexible energy storage film based on PVDF matrix has very extensive application. The electrical properties of PVDF composite films doped by nanometer MnO_2 was studied in this research, and the influences of MnO_2 content on dielectric constant, breakdown strength and energy storage properties were systematic investigated. The results indicated that using MnO_2 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 MnO_2 is 10 wt%. In addition, both large energy storage density (1.67 J/cm~3) and high energy storage efficiency (81.9%) are obtained in composite film with 10 wt% MnO_2. The enhancement of dielectric constant and energy storage efficiency are due to the ionic polarization of MnO_2 under applied electric field. Moreover, the effect of MnO_2 on electron trapping improves the breakdown strength and energy storage density of MnO_2/PVDF composite films. This work provides a feasible route for designing flexible composites with excellent energy storage performance.