Nanoplex-driven energy storage in relaxor antiferroelectrics†

The energy storage performance of NaNbO₃, which possesses a relaxor antiferroelectric R-phase structure, is limited by the large hysteresis of its antiferroelectric phase transition and a lack of evidence for antiparallel polarization. Atomic-level characterization using scanning transmission electron microscopy directly revealed an antiparallel polarization configuration at the A/B sites in the relaxor antiferroelectric R phase. A novel nanoplex-driven architecture was constructed that integrated short-range ordered antiferroelectric nanodomains with highly disordered relaxor ferroelectrics, reducing the antiferroelectric–ferroelectric phase transition barrier by optimizing the alignment and interactions of polar nanodomains in the relaxor antiferroelectric. In a multilayer ceramic capacitor based on NaNbO₃, an energy density of 22.9 J cm⁻³ was achieved, along with an ultra-high energy storage efficiency of 94.3% at an electric field of 1500 kV cm⁻¹. This performance is comparable to those of contemporary state-of-the-art energy storage dielectrics and provides a critical benchmark for the advancement of high-performance ceramic dielectric capacitors.