Li Dengfeng, Zheng Zihao, Yang Bin, Chen Longyu, Shi Dean, Guo Jinming, Nan Ce-Wen
Electron Microscopy Center, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, School of Materials Science and Engineering, Hubei University, Wuhan, 430062, China.
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
Adv Mater. 2025 Mar;37(10):e2409639. doi: 10.1002/adma.202409639. Epub 2025 Jan 31.
Dielectric ceramics with high energy storage performance are crucial for the development of advanced high-power capacitors. However, achieving ultrahigh recoverable energy storage density and efficiency remains challenging, limiting the progress of leading-edge energy storage applications. In this study, (BiNa)TiO (BNT) is selected as the matrix, and the effects of different A-site elements on domain morphology, lattice polarization, and dielectric and ferroelectric properties are systematically investigated. Mg, La, Ca, and Sr are shown to enhance relaxation behavior by different magnitudes; hence, a high-entropy strategy for designing local polymorphic distortions is proposed. Based on atomic-scale investigations, a series of BNT-based high-entropy compositions are designed by introducing trace amounts of Mg and La to improve the electric breakdown strength and further disrupt the polar nanoscale regions (PNRs). A disordered polarization distribution and ultrasmall PNRs with a minimum size of ≈1 nm are detected in the high-entropy ceramics. Ultimately, a high recoverable energy density of 10.1 J cm and an efficiency of 90% are achieved for (CaSrBaMgLaBiNa)TiO. Furthermore, it displays a high-power density of 584 MW cm and an ultrashort discharge time of 27 ns. This work presents an effective approach for designing dielectric energy storage materials with superior comprehensive performance via a high-entropy strategy.
具有高储能性能的介电陶瓷对于先进高功率电容器的发展至关重要。然而，实现超高的可恢复储能密度和效率仍然具有挑战性，这限制了前沿储能应用的进展。在本研究中，选择（BiNa）TiO（BNT）作为基体，并系统研究了不同A位元素对畴形态、晶格极化以及介电和铁电性能的影响。结果表明，Mg、La、Ca和Sr能不同程度地增强弛豫行为；因此，提出了一种设计局部多晶型畸变的高熵策略。基于原子尺度的研究，通过引入微量的Mg和La来提高击穿场强并进一步破坏极性纳米区域（PNR），设计了一系列基于BNT的高熵组合物。在高熵陶瓷中检测到无序的极化分布和最小尺寸约为1 nm的超小PNR。最终，（CaSrBaMgLaBiNa）TiO实现了10.1 J/cm的高可恢复能量密度和90%的效率。此外，它还具有584 MW/cm的高功率密度和27 ns的超短放电时间。这项工作通过高熵策略提出了一种设计具有优异综合性能的介电储能材料的有效方法。
