通过Li离子诱导的0.6Na0.5Bi0.5TiO3–0.4Sr0.7Bi0.2TiO3弛豫铁电陶瓷在低电场下形成束腰型P–E回线实现增强的能量存储性能

As a key material for pulsed power systems, lead-free dielectric ceramics have attracted attention for their excellent power density and rapid charge–discharge characteristics. This study prepared dielectric ceramics by doping (Bi 0.5 Li 0.5 )TiO 3 (BLT) into a 0.6Na 0.5 Bi 0.5 TiO 3 –0.4Sr 0.7 Bi 0.2 TiO 3 (NBST) matrix. A detailed analysis was conducted on the crystal structure, surface morphology, and electrical characteristics. It is evident from the results that the incorporation of Li⁺ efficiently facilitates the off-center displacement of the A-site ions. This not only increases the density and size of the polar nanoregions (PNRs), but also enhances their interaction with the external electric field, thereby significantly improving the maximum polarization strength. Benefiting from the formation of a beam-waisted P – E loop, the modified NBST–0.06BLT ceramics achieve enhancing energy storage characteristics. A substantial polarization difference (Δ P ) of 43 μC/cm 2 is obtained, along with a notable recoverable energy density of 2.74 J/cm 3 and 75.75% efficiency under an applied field of only 180 kV/cm. Additionally, the ceramics show excellent stability in energy storage property (ESP) across frequencies of 1–100 Hz and temperatures ranging from 40 to 160 °C. Notably, the NBST–0.06BLT ceramics demonstrate favorable charge–discharge characteristics, including a high discharge power density (53 MW/cm 3 ), a substantial energy density (1.28 J/cm 3 ), and a short discharge time ( t 0.9 ≈ 253 ns). These remarkable characteristics of NBST–0.06BLT ceramics highlight their promising application in pulsed power systems.