High-entropy superparaelectrics with locally diverse ferroic distortion for high-capacitive energy storage

Superparaelectrics are considered promising candidate materials for achieving superior energy storage capabilities. However, due to the complicated local structural design, simultaneously achieving high recoverable energy density (Wrec) and energy storage efficiency (eta) under high electric fields remains a challenge in bulk superparaelectrics. Here, we propose utilizing entropy engineering to disrupt long-range ferroic orders into local polymorphic distortion disorder with multiple BO6 tilt types and diverse heterogeneous polarization configurations. This strategy reduces the switching barriers, thereby facilitating the emergence of superparaelectric behaviors with ideal polarization forms. Furthermore, it enables high polarization response, negligible remnant polarization, delayed polarization saturation, and enhanced breakdown electric fields (Eb) in high-entropy superparaelectrics. Consequently, an extraordinary Wrec of 15.48 J cm-3 and an ultrahigh eta of 90.02% are achieved at a high Eb of 710 kV cm-1, surpassing the comprehensive energy storage performance of previously reported bulk superparaelectrics. This work demonstrates that entropy engineering is a viable strategy for designing high-performance superparaelectrics. High-entropy superparaelectrics with locally diverse ferroic distortion simultaneously achieve ultrahigh energy density and ultrahigh energy storage efficiency under large electric fields.