Antiferroelectric‐like High‐entropy Superparaelectric Enables Ultrahigh Energy‐storage in Multilayer Capacitors

ABSTRACT Multilayer ceramic capacitors (MLCCs) are promising candidates for miniaturizing advanced electronic systems, owing to their high‐power density and rapid discharge capabilities. However, simultaneously achieving high energy density and near‐zero energy loss remains a long‐standing challenge, hindering their application potential as next‐generation energy‐storage devices. Here, we propose a bottom‐up self‐assembly strategy within a disordered (Sr 0.2 Ca 0.2 Pb 0.2 Na 0.2 La 0.2 )TiO 3 high‐entropy ceramic matrix to construct a nanodomain configuration. The high‐entropy design guarantees a locally compositional inhomogeneous platform with fully lowered energy barrier for dipole switching, and the subsequent substitution of strong polar Bi effectively facilitates the progress of nanodomain assembly. The synergistic regulation of lattice structure and anisotropic domain configuration gives rise to relaxor antiferroelectric‐like polarization behavior, simultaneously enabling high polarization intensity and fast dipole switching. Consequently, a concurrent breakthrough with a high energy density of 24.7 J cm −3 and an ultrahigh efficiency of 96.5% is achieved in the antiferroelectric‐like high‐entropy superparaelectric MLCCs. This work establishes a new opportunity for manipulating polarization profiles and designing high‐performance energy storage dielectrics.