Excellent Energy-Storage Performance in BNT-SST-LMN Lead-Free Relaxor Ferroelectric Ceramics with High Electrical Homogeneity

Relaxor ferroelectric materials have received increasing attention in pulse power devices due to the high power density and rapid charge–discharge capability. However, challenges exist in relaxor ferroelectric behavior because of their low electric breakdown strength. In this article, a large recoverable energy density of 5.94 J/cm 3, together with a high energy efficiency of 86.9%, is achieved synchronously in La(Mg 2/3 Nb 1/3 )O 3 (LMN) modified Bi 0.5 Na 0.5 TiO 3 -Sr 0.7 Sm 0.2 TiO 3 (BNT-SST) ceramic. It is suggested that the addition of LMN reduces the grain size and enhances the electrical homogeneity, which boosts the electric breakdown strength of sample ceramics. In addition, in 0.03LMN modified 0.97(BNT-SST) ceramic, a good discharge energy density of 3.9 J/cm 3 and a transient discharge time of 65 ns are attained. Meanwhile, the outstanding stability in the temperature range of 20–100 °C and frequency range of 1–100 Hz is observed in the above component. These results indicate that BNT-SST-LMN ceramic has potential as an energy-storage medium.