Simultaneously achieving high energy storage and charge-discharge performance by Nd-doped Sr0.7Bi0.2TiO3 lead-free relaxor ferroelectric ceramics

Dielectric capacitors have been extensively studied in electronic and power systems based on their high power density and ultra-fast discharge rates. In this study, the dielectric, energy storage and charge-discharge properties of Sr0.7Bi0.2TiO3-based lead-free relaxor ferroelectric ceramic were investigated. The dielectric breakdown strength was significantly improved by introducing the rare earth element Nd, which was attributed to the rise in resistivity and large band gap. The results show that Sr0.7Bi0.15Nd0.05TiO3 obtain a high recoverable energy storage density of 2.34 J/cm3 with high efficiency of 92%. In addition, pulsed charge-discharge tests demonstrated that Sr0.7Bi0.15Nd0.05TiO3 possess a high power density of 73.5 MW/cm3, a short discharge period of 0.1 μs, and a pulsed discharge energy density of 2.0 J/cm3. Meanwhile, the energy storage performance of Sr0.7Bi0.15Nd0.05TiO3 exhibits excellent stability of temperature, frequency and cycling. This work provides a systematic study and a new strategy for enhancing the performance of SBT ceramics.