Tuning Ferroelectric Response of Electroactive Materials by Controlling Multilayered Structures to Achieve Excellent Energy Storage Performance

Flexible ferroelectric polymers are key candidates for flexible capacitive electronic devices. However, there is a lack of functional and accessible methods to control the ferroelectric response of polymers. Herein, a novel and effective approach is adopted to tune the ferroelectric response of polymers, over the conventional methods (graft or block copolymerization). Specifically, a central ferroelectric poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) layer is sandwiched between shielding layers (polymethacrylate (PMMA)). The differently distributed electric fields were generated in inner and outer layers owing to a larger polarization gradient between PMMA and P(VDF‐TrFE), building a competition in the local ferroelectric layer. Controlling the polarization and thickness of the shielding layer may result in the electric field in it being lesser than the electric field in the ferroelectric layer during reverse poling, leading to a part of the dipoles reverting to the initial direction in the ferroelectric layer. Then dipoles along antiparallel directions coexist in P(VDF‐TrFE), leading to antiferroelectric‐like behavior. With the low remnant polarization, antiferroelectric‐like films possess an excellent discharge energy density (11.72 J cm⁻³ at 3300 kV cm⁻¹). Given the practicability and simplicity of tuning the ferroelectric response, it is firmly believed that this method will cut a conspicuous figure in a supercapacitor with ultrahigh energy density and discharged efficiency.