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

Abstract

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 (U e ≈ 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 U e is improved by 2.3 times, η by 1.2 times, and E b by 1.5 times. This research presents a viable answer for applying PVDF-based high-energy-storage film capacitors.

Improved Energy Storage Performance of Composite Films Based on Linear/Ferroelectric Polarization Characteristics

“…As shown in Figure 2 b, the bilayer dielectric constants films at a frequency of 1 kHz are 7.14, 5.27, and 3.33, respectively. The dielectric constants decreased with increasing BOPP volume fraction in accordance with the theoretical dielectric constant law [ 31 , 32 , 33 ]. The dielectric loss associated with the PVTC/BOPP bilayer film is lower than that of the PVTC film in a given frequency range, which results from the lower dielectric loss of the incorporated BOPP film with linear polarization characteristics.…”

Sandwich-Structured PC/PVDF-Based Energy Storage Dielectric with Inorganic Doping to Regulate Electric Field Distribution

“…As observed in the figure, the distinctive peaks of the PC outer insulation layer and the PC/PVDF polarization layer, respectively, correlate with the diffraction peaks at 2θ of 17.2 and 20.01°, and no other miscellaneous diffraction peaks are generated. Moreover, the diffraction peaks at 2θ of 27.56, 36.13, 41.3, and 54.34° in the figure correspond to the (110), (101), (111), and (211) crystal planes of TiO 2 , respectively . The reflection peaks’ amplitude keeps increasing given the rise in TiO 2 content in the interlayer, thus proving the introduction of TiO 2 .…”

“…Moreover, the diffraction peaks at 2θ of 27.56, 36.13, 41.3, and 54.34°in the figure correspond to the (110), ( 101), (111), and (211) crystal planes of TiO 2 , respectively. 20 The reflection peaks' amplitude keeps increasing given the rise in TiO 2 content in the interlayer, thus proving the introduction of TiO 2 . However, due to the weak diffraction peaks corresponding to the (210), (220), (002), (310), (301), and (112) crystal planes of TiO 2 in the figure, all P-X-P sandwich films did not show the characteristic peaks corresponding to them.…”

“…18 (PC)/PVDF composite media obtained by blending the linear polymer PC with PVDF and its derivatives through a simple blending strategy has excellent energy storage properties. 19 For example, Zhang 20 et al prepared PC/PVDF composite media by a coblending strategy. The binary mixed PC/PVDF material with 40 vol % linear polymer PC provides beneficial energy storage capabilities (U e ∼ 10.31 J/cm 3 , η ∼ 63.3%).…”