The energy storage performance of Sm3+ and Hf4+ co-doped AgNbO3 lead-free antiferroelectric ceramic

Abstract Antiferroelectrics with excellent energy storage density have attracted considerable attention due to their potential applications in electric vehicles, pulsed power weapons, etc. With the trend of environmental protection, the lead-free antiferroelectric AgNbO 3 is a promising candidate for energy storage applications. However, the limited recoverable energy density ( W rec ) of AgNbO 3 severely restricts its application in high-power systems. To enhance the W rec of AgNbO 3 , the A/B-site Sm 3+ /Hf 4+ co-doping approach was adopted. It positively influenced the energy density and efficiency in AgNbO 3 by simultaneously increasing the maximum polarization and breakdown strength. The optimized W rec of 1.98 J cm −3 and high energy storage efficiency ( η ) of 64% were obtained in the MnO 2 -doped Ag 0.97 Sm 0.01 Nb 0.99 Hf 0.01 O 2.995 ceramic at an electric field of 202 kV cm −1 . This work indicates that the A- and B-site substitution with donor and acceptor dopants and using MnO 2 as a sintering aid is an effective strategy for developing high-performance ceramic capacitors for energy storage applications.