Enhanced Energy Storage Performance of Doped Modified PC/PVDF Coblended Flexible Composite Films

The rapid development of the clean energy industry has given great impetus to energy-efficient storage and conversion technologies. Film capacitors have attracted much attention because of their higher charge and release rates, greater energy density, and extended life cycle. But the lower recharging and discharging efficiency and insulation properties pertaining to the electricity used in capacitors limit the improvement of their energy storage performance. In this paper, the addition of the linear polymer polycarbonate (PC) to polyvinylidene fluoride (PVDF) through a blending strategy and the subsequent acquisition of the high-dielectric nanofiller titanium dioxide (TiO2) to the blended matrix is expected to achieve synergistic optimization of the insulation and polarization properties, thereby enhancing the energy storage performance of the mixed media. The findings show that great storage of energy productivity (Ue ≈ 11.43 J/cm3, η ≈ 57.08%) is obtained for 40 vol % PC/PVDF-x wt %-TiO2 at an optimum field strength of 450 kV/mm when the TiO2 doping amount x is 0.9 wt %. Compared with pure PVDF, its Ue is improved by 2.3 times, η by 1.2 times, and Eb by 1.5 times. This research presents a viable answer for applying PVDF-based high-energy-storage film capacitors.