Design of High‐Entropy Relaxor Ferroelectrics for Comprehensive Energy Storage Enhancement
Bingbing Yang, Yiqian Liu, Chengzhuan Gong, Shun Lan, Zhifang Zhou, Xuebin Zhu, Ce‐Wen Nan, Yuan‐Hua Lin
Abstract
Abstract For an ideal electrostatic energy storage dielectric capacitor, the pursuit of simultaneously high energy density and efficiency presents a formidable challenge. Typically, under an applied electric field, an increase in energy density is usually accompanied with a deteriorated energy storage efficiency due to the escalated hysteretic loss, which is harmful to the reliability of the capacitor. Thus, a well‐balanced performance of improved energy density and maintained high efficiency is highly demanded. In this work, a structure with amorphous phases embedded in polycrystalline nanograins using the entropy tactic, leading to a higher transport barrier of carrier is constructed. Hence, the hysteretic loss is largely suppressed at a high electric field and the high polarization is still sustained in the high‐entropy film. Consequently, an ultrahigh energy density of 139.5 J cm −3 with a high efficiency of 87.9%, and a high figure of merit of 1153 are simultaneously achieved in the high‐entropy Ba 2 Bi 4 Ti 5 O 18 ‐based relaxor ferroelectric. This work offers a promising avenue in materials structure design for advanced high‐power energy storage applications.