Outstanding Energy Storage Performance of NBT-Based Ceramics under Moderate Electric Field Achieved via Antiferroelectric Engineering

Ultrahigh energy-storage performanceof dielectric ceramic capacitorsis generally achieved under high electric fields (HEFs). However,the HEFs strongly limit the miniaturization, integration, and lifetimeof the dielectric energy-storage capacitors. Thus, it is necessaryto develop new energy-storage materials with excellent energy-storagedensities under moderate electric fields (MEFs). Herein, the antiferroelectricmaterial Ag0.9Ca0.05NbO3 (ACN) wasused to modify the relaxor ferroelectric material 0.6Na(0.5)Bi(0.5)TiO(3)-0.4Sr(0.7)Bi(0.2)TiO(3) (NBT-SBT). The introduction of ACN resultsin high polarization strength, regulated composition of rhombohedral(R3c) and tetragonal (P4bm), nanodomains, and refined grain size. An outstandingrecoverable energy density (W (rec) = 4.6J/cm(3)) and high efficiency (& eta; = 82%) were realizedunder an MEF of 260 kV/cm in 4 mol % ACN-modified NBT-SBT ceramic.The first-principles calculation reveals that the interaction betweenBi and O is the intrinsic mechanism of the increased polarization.A new parameter & UDelta;P/E (b) was proposed to be used as the figure of merit to measure the energy-storageperformance under MEFs (& SIM;200-300 kV/cm). This work pavesa new way to explore energy-storage materials with excellent-performanceMEFs.