Engineering relaxors by embedding ultra-weak polar regions for superior energy storage.

Dong, Xiaoyan; Fu, Zhengqian; Wang, Zhipeng; Lv, Xiang; Wu, Jiagang · Nat Commun · 2025

basic_science · Level V

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Abstract

Dielectric capacitors with excellent energy storage performance are essential for advanced electronic systems. Nonetheless, achieving high recoverable energy storage density (W<sub>rec</sub>) and efficiency (η) remains highly challenging. Here, we propose a strategy of embedding ultra-weak polar regions in the strong polar fluctuation matrix to achieve substantial enhancements of energy storage properties, which is successfully verified by preparing heterogeneous relaxors using tape-casting. Phase-field simulations confirm a fast response and recovery of polarization in this unique heterogeneity. Accordingly, the hysteresis is virtually eliminated while realizing high breakdown field strength (E<sub>b</sub>) and high polarization. The appropriately fined grain size also contributes to enhancing E<sub>b</sub>. Hence, a giant W<sub>rec</sub> of 13.2 J cm<sup>-3</sup> and an ultra-high η of 92.5 % are achieved, superior to other relaxors prepared by the tape-casting/repeated rolling process methods to date. This work provides a viable practical paradigm for the development of high-performance relaxors for capacitors.