Bi(Ni _1/2 Hf _1/2 )O ₃ ‐modified BNT‐based ceramics for energy storage capacitors

Abstract Dielectric capacitors with high power density are fundamental and essential components in advanced electric and electrical systems. However, poor energy storage property at low electric fields is a long‐term challenge limiting their applications. In this work, the BiMeO 3 ‐based compound Bi(Ni 1/2 Hf 1/2 )O 3 (BNH) is used to modify BNT‐based ceramics to strengthen their dielectric and ferroelectric properties. The pseudo‐cubic phase BNT‐based ceramics exhibit clear grain and grain boundary, and the grain size grows as BNH content increases. Dielectric constant at dielectric peak and corresponding transition temperature T m decrease, and energy density increases in BNH‐modified BNT‐based ceramics with increasing BNH content. 20% mol BNH‐modified (Ba 0.3 Sr 0.7 ) 0.35 (Bi 0.5 Na 0.5 ) 0.65 TiO 3 (BNBST) ceramics achieve a high recoverable energy density of 3.3 J/cm 3 at a low electric field of 210 kV/cm, which is 2.2 times that of pure BNT‐based ceramics. Moreover, energy storage properties of BNBST‐0.2BNH ceramics exhibit robust stability and good reliability. This work demonstrates that BNH modification is a useful way to enhance dielectric energy density of BNT‐based relaxor ferroelectrics at low electric field, and further expands the use of the BiMeO 3 ‐based compound(s) on influencing polarization behavior of BNT‐based relaxor ferroelectrics.