Antiferroelectric AgNbO3@KH550 Doped PVDF/PMMA Composites with High Energy Storage Performance

The residual polarization of antiferroelectric ceramics is very small, yet they possess high energy storage density and efficiency. Incorporating antiferroelectric ceramic particles into a polymer matrix is beneficial for improving the energy storage performance of composites. However, excessive amounts of ceramic particles can lead to aggregation within the polymer, resulting in defects and a significant reduction in composite film performance. In this study, the antiferroelectric AgNbO3 is selected as the filler and modified with silane coupling agent KH550. poly(vinylidene fluoride) (PVDF) and polymethyl methacrylate (PMMA) are blended as the matrix, and the energy storage performance of the composite is improved by adjusting the additional amount of PVDF. The structure, dielectric properties, and energy storage properties of the composites are systematically studied. The results show that hydrogen bonds are formed between PVDF and PMMA, and PVDF and PMMA are tightly bonded under the action of hydrogen bonds. The compatibility of PVDF with PMMA is optimal when the mass fraction of PVDF is 30 wt%. Moreover, with the synergistic effect of the antiferroelectric filler AgNbO3, the breakdown strength of AgNbO3/PVDF/PMMA composites reaches 430 kV mm−1, and the energy storage density reaches 14.35 J cm−3. A series of AgNbO3@KH550/poly(vinylidene fluoride) (PVDF)/polymethyl methacrylate (PMMA) composites are successfully prepared. And the influence of polymer matrix composition on the microstructure and energy storage properties of the composites is discussed. In this work, the 0.3 wt% AgNbO3@KH550/30 wt% PVDF/PMMA composite has an energy storage density of 14.35 J cm−3 at an electric field of 430 kV mm−1.