Synergistic Enhancement of Energy Storage Performance in PVTC via Carrier Transport Suppression and Adaptive Electric Field Distribution

Ferroelectric polymers exhibit enormous potential in dielectric capacitors due to unique electrical properties, such as high dielectric constant and ferroelectricity. However, their poor insulation performance and high dielectric loss lead to energy storage properties that are insufficient for practical applications. In this article, a synergistic strategy of carrier transport suppression and electric field distribution regulation is proposed to enhance their energy storage performance. Specifically, by introducing Bis-PCBM, an organic molecular semiconductor with high electron affinity, into highly polar poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVTC), deep traps are constructed to inhibit carrier transport. Furthermore, three-layer composite films of P-0.9M/PET/P-0.9M (PTP) and PET/P-0.9M/PET (TPT) are fabricated by using high-insulation polyethylene terephthalate (PET). Finite element simulation reveals that the redistribution of the electric field in the trilayer films is achieved based on the difference in dielectric constants of the polymers, enabling the insulating layers to withstand higher electric fields and the polar layers to operate in a high-efficiency range. Especially at high temperatures, the marked increase in the dielectric constants of PVTC shifts the electric field distribution with the consequence that the polar layers bear a lower share of the overall electric field. This temperature-adaptive self-regulation behavior of the electric field distribution significantly reduces the failure probability and enhances the energy storage performance. At 25 °C, the breakdown field strength (Eb) of TPT reaches 578.8 MV/m, with an energy storage density (Ue) of 8.18 J/cm3 and a charge–discharge efficiency (η) of 72.33%, which are 56.4, 50.6, and 71.8% higher than those of PVTC, respectively. Notably, even at 100 °C, TPT maintains a breakdown strength of 456.8 MV/m, an Ue of 4.22 J/cm3, and a η of 49.70%, achieving significant improvements (44.4, 104.9, and 208.5%) compared with P-0.9M. This work provides a simple, effective, and field-adaptive strategy for enhancing both the insulation and energy storage performance of ferroelectric polymers.