Novel BaTiO3-Based, Ag/Pd-Compatible Lead-Free Relaxors with Superior Energy Storage Performance

Ceramic dielectrics are reported with superior energy storage performance for applications, such as power electronics in electrical vehicles. A recoverable energy density (W-rec) of similar to 4.55 J cm(-3) with eta similar to 90% is achieved in lead-free relaxor BaTiO3-0.06B(i2/3)(Mg1/3Nb2/3)O-3 ceramics at similar to 520 kV cm(-1). These ceramics may be co-fired with Ag/Pd, which constitutes a major step forward toward their potential use in the fabrication of commercial multilayer ceramic capacitors. Compared to stoichiometric Bi(Mg2/3Nb1/3)O-3-doped BaTiO3 (BT), A-site deficient Bi-2/3(Mg1/3Nb2/3)O-3 reduces the electrical heterogeneity of BT. Bulk conductivity differs from the grain boundary only by 1 order of magnitude which, coupled with a smaller volume fraction of conducting cores due to enhanced diffusion of the dopant via A-site vacancies in the A-site sublattice, results in higher breakdown strength under an electric field. This strategy can be employed to develop new dielectrics with improved energy storage performance.