Enhanced electrical energy storage performance in NaNbO₃-based antiferroelectric ceramics modified with Sr(Mg1/3Nb2/3)O3

NaNbO 3 (NN) has potential applications in energy storage devices due to its antiferroelectricity and environmentally friendly characteristics, but its low dielectric breakdown field strength ( E b ) and energy storage efficiency ( ƞ ) limit practical applications. In this study, the structure and electrical characteristics of NaNbO 3 were modulated by introducing Sr(Mg 1/3 Nb 2/3 )O 3 (SMN) to optimize its energy storage performance. The (1- x )NN- x SMN solid solution was synthesized using a classic solid-state reaction approach. According to X-ray diffraction analysis results, the prepared ceramics exhibit a pure phase when x is less than or equal to 0.15. With the increment of x , SMN disturbs the long-range polar order, induces pronounced relaxation ferroelectric phase (RFE) with reduced remnant polarization ( P r ), and enhances E b , leading to significant increases in recoverable energy storage density ( W rec ) and η . The optimized composition 0.875NN-0.125SMN has the best dielectric energy storage properties with a W rec of 1.28 J/cm 3 and an η of 88%.