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

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.