Local Diverse Polarization Optimized Comprehensive Energy‐Storage Performance in Lead‐Free Superparaelectrics

• Published in: Advanced materials (Weinheim) Vol. 34; no. 44; pp. e2205787 - n/a
• Main Authors: Chen, Liang, Wang, Na, Zhang, Zhifei, Yu, Huifen, Wu, Jie, Deng, Shiqing, Liu, Hui, Qi, He, Chen, Jun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.11.2022
• Subjects: Ceramics; Charge density; Configurations; Dielectrics; Discharge; Electric fields; Energy storage; Flux density; Frequency stability; Heat loss; lead‐free dielectric ceramics; local diverse polarization; Materials science; Miniaturization; Polarization; relaxor ferroelectrics; Scanning transmission electron microscopy; superparaelectrics
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202205787

Lead‐free dielectric ceramics with ultrahigh energy‐storage performance are the core components used in next‐generation advanced pulse power capacitors. However, the low energy storage density largely hinders their development towards miniaturization, lightweight, and integration. Here, an effective strategy of constructing local diverse polarization is designed in superparaelectrics to realize an ultrahigh energy storage density of ≈10.59 J cm−3 as well as a large efficiency of ≈87.6%. The excellent comprehensive energy‐storage performance is mainly attributed to the design of ultrasmall polar nanoregions with local diverse polarization configuration, confirmed by scanning transmission electron microscopy, leading to the reduced heat loss, substantially enhanced polarization, and breakdown electric field compared to ceramics with single polarization configuration. Benefiting from these features, outstanding temperature/frequency/cycling stability and superior charge/discharge performance (power density ≈187.5 MW cm−3, discharge energy density ≈3.52 J cm−3, discharge rate ≈77 ns) are also achieved. This work demonstrates that local diverse polarization is a super strategy to design new dielectric materials with high energy‐storage performance. Excellent energy‐storage properties with an ultrahigh recoverable energy storage density ≈10.59 J cm−3 and a large efficiency ≈87.6% are realized in lead‐free relaxor ferroelectrics, which is responsible by the local diverse polarization design, leading to the ultrasmall polar nanoregions, reduced heat loss, substantially enhanced polarization, and breakdown electric field compared to single polarization configuration.