Structure, dielectric, and relaxor properties of BaTiO3-modified high-entropy (Bi0.2Na0.2K0.2Ba0.2Ca0.2)TiO3 ceramics for energy storage applications

High-entropy (1− x )Bi 0.5 Na 0.5 K 0.5 Ba 0.5 Ca 0.5 TiO 3 - x BaTiO 3 (BNKBCT-BT, x  = 0.02, 0.06, 0.10, 0.14 and 0.20) ceramics are successfully prepared via the solid-state reaction method. The XRD and Raman analyses reveal that all samples exhibit a pseudo-cubic phase structure. With increasing x , the a is gradually increased, resulting in the expansion of unit cell volume. A strong frequency dispersion appeared around T m , demonstrating that the as-prepared ceramics is a relaxor ferroelectric . Owing to the increase in the degree of lattice disorder, as well as relaxation and thermal evolution of PUs, the as-prepared ceramics exhibit a broad relaxor behavior. The Δ P is effectively increased by doping BT, which is conducive to achieving excellent energy storage properties. Moreover, W rec of all samples is more than 1.31 J/cm 3 and, at x  = 0.20, W rec reaches the maximum value of 2.24 J/cm 3 at 140 kV/cm. These results indicate that high-entropy (1− x )BNKBCT- x BT ceramics are promising materials for energy storage applications.