Significantly Improved Energy Storage Performance of PVDF Ferroelectric Films by Blending PMMA and Filling PCBM

Abstract

The increasing energy problem and the demand of environmental protection raise higher requirements for the development of clean energy. Dielectric capacitors have attracted lots of attention as a supporting facility of energy storage and conversion for clean energy, but their further development is limited by the low energy storage performance. In this paper, all-organic composite dielectrics were reported, with a poly(methyl methacrylate) (PMMA)/poly(vinylidene fluoride) (PVDF) composite dielectric with different mixing ratios as the matrix and the organic molecular semiconductor with high electron affinity [6,6]-phenyl C61 butyrate acid methyl ester (abbreviated as PCBM) as fillers. The related test results show that with the increase in the doping contents of PCBM, the energy storage density increases obviously. When the doping content of PCBM is 0.9 wt %, the PMMA/PVDF-based organic composite dielectric possesses an optimal breakdown field of 685.67 kV mm-1, accompanying excellent energy storage performances (Ue, ∼21.89 J cm-3 ν, ∼70.34%). The PVDF blended with PMMA strategy not only restrains the ferroelectric polarization loss of PVDF but also improves the breakdown strength of the polymer. More importantly, the polarization and breakdown strength of the composites can be synergistically enhanced by filling with PCBM fillers.