Ultrahigh Energy-Storage Performances in Lead-free NaBiTiO-Based Relaxor Antiferroelectric Ceramics through a Synergistic Design Strategy.

Dielectric ceramics with outstanding energy-storage performances are nowadays in great demand for pulsed power electronic systems. Here, we propose a synergistic design strategy to significantly enhance the energy-storage properties of (1 - )(0.94NaBiTiO-0.06BaTiO)-CaTiTaO solid solution ceramics through introducing polar nanoregions, shifting rhombohedral to tetragonal phase transition below room temperature (stable antiferroelectric characteristic), as well as increasing the band gap in the system. Ultrahigh energy-storage properties with a record value of recoverable energy-storage density ∼ 9.55 J/cm and a high efficiency η ∼ 88% are achieved in NaBiTiO-based bulk ceramics with = 0.24. Moreover, high (>3.4 J/cm) and η (>90%) with a variation of less than 6% can be observed in a wide frequency and temperature frequency range of 5-200 Hz and 25-140 °C. Our research result not only indicates the great possibility of NaBiTiO-based lead-free compositions to replace lead-based energy-storage ceramics but also gives an effective strategy to design ultrahigh energy-storage performances for eco-friendly ceramics.