Excellent Energy Storage Performance of Ferroconcrete-like All-Organic Linear/Ferroelectric Polymer Films Utilizing Interface Engineering

Ferroelectric polymers are regarded as the preferred material in dielectric energy storage devices because of their high dielectric constant. However, their relatively low breakdown strength and efficiency restrict their practical application. This work combines coaxial spinning and hot pressing to compound the highly insulating linear poly(methyl methacrylate) (PMMA) and ferroelectric poly(vinylidene fluoride) (PVDF) to obtain a PMMA/PVDF all-organic film with a ferroconcrete-like structure. Further, improvements in the energy storage performance over those of the pristine polymer were achieved via modulation of the PMMA to PVDF ratio. The 45% PMMA/PVDF film had an energy storage density of 17.7 J/cm3 and an energy efficiency of 73% at 640 kV/mm. Moreover, 51% PMMA/PVDF exhibited the best energy storage density (U = 20.7 J/cm3, η = 63% at 630 kV/mm). This work, therefore, provides a new idea for the design of all-organic polymer films for the field of energy storage.