Tailoring Dielectric and Energy Storage Performance of PVDF-Based Relaxor Ferroelectrics with Hydrogen Bonds

Abstract

Polymer-based dielectrics with high energy density and low dielectric loss are urgently needed in microelectronic equipment and high-power density electric energy storage devices. In an effort to overcome the disadvantage of the high energy loss of poly­(vinylidene fluoride) (PVDF)-based ferroelectric fluoropolymers, herein, a series of poly­(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-g-poly­(vinyl alcohol) [P­(VTrCT)-g-PVA] were fabricated using the reversible addition–fragmentation chain transfer polymerization procedure. The PVA side chain shows great compatibility with the PVDF main chain and the hydrogen bond could be constructed among the hydroxyl and ester groups, which is responsible for the suppressed ferroelectric loss and enhanced breakdown strength and thus improved energy density and charge–discharge efficiency observed in the P­(VTrCT)-g-PVAs. The graft copolymer containing 23 mol % PVA shows the maximum discharge energy density of 13.6 J/cm3 at 500 MV/m. The work demonstrates that the hydrogen bond constructed based on the hydroxyl group may offer a strategy to tune the ferroelectric and energy storage performance of PVDF-based fluoropolymers.

Strategies Involved in Enhancing the Capacitive Energy Storage Characteristics of Poly(vinylidene fluoride) Based Flexible Composites

“…Apart from the above-mentioned techniques, there are also some other techniques that are reported to be useful in augmenting the energy storage features of PVDF-based devices. Zhang et al [165] fabricated poly(vinylidene fluoride-cotrifluoroethylene-co-chlorotrifluoroethylene)-g-poly(vinyl alcohol) [P-(VTrCT)-g-PVA] composites where the energy storage performance was improved via the hydrogen bonding between [47] (Reproduced with permission from Ref. [47].…”

Controllable synthesis and structural design of novel all-organic polymers toward high energy storage dielectrics

“…In the previous section, it was introduced that the same research group prepared a series of P(VDF-TrFE-CTFE)-g-PVA using RAFT procedure. And H-bond could be constructed among the -OH and ester groups, which is responsible for the suppressed ferroelectric loss and enhanced E b and thus improved U e and η (Zhang et al, 2021). Wang R. et al (2022) reported a kind of all-organic ultrahighenergy-density dielectric composites materials consisting of ferroelectric polymer P(VDF-HFP) and glucose, exhibiting record U e (37.7 J/cm 3 ) that outperforms the state-of-the-art dielectric polymer composites.…”

“…In addition, Zhicheng Zhang’s group fabricated a series of P(VDF-TrFE-CTFE)- g -PVA with high U e and low dielectric loss for using RAFT procedure ( Zhang et al, 2021 ). The PVA side chain shows great compatibility with the PVDF main chain and the hydrogen bond could be constructed among the hydroxyl and ester groups, which is responsible for the suppressed ferroelectric loss and enhanced E b and thus improved U e and η .…”

“…In the previous section, it was introduced that the same research group prepared a series of P(VDF-TrFE-CTFE)- g -PVA using RAFT procedure. And H-bond could be constructed among the -OH and ester groups, which is responsible for the suppressed ferroelectric loss and enhanced E b and thus improved U e and η ( Zhang et al, 2021 ).…”

High energy storage density and low energy loss achieved by inserting charge traps in all organic dielectric materials

“…3 As suggested by the equation E b = 0.6( Y / ε 0 ε r ) 0.5 , where Y is Young's modulus, Y has a dominant effect on E b and thus U e . 18 Many glassy polymers with high T g and Y have been developed and tested for dielectric films during the past few years. Cao's group synthesized a series of dipolar relaxation enhanced cyclic olefins with a U e of ∼9 J cm −3 , an E b of ∼750 MV m −1 and rather high T g (∼178 °C).…”