Ultrahigh energy storage performance in (Bi,Na)TiO 3 -based relaxor ferroelectrics via multi-scale high-entropy design

A multi-scale high-entropy design enables synergistic control over lattice, microstructure, and electronic structure in (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 -based ceramics, yielding superior W rec ∼10.72 J cm −3 and η ∼86.9% at 698 kV cm −1 .