School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha, Hunan, 410114, China.
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
Adv Sci (Weinh). 2023 Jun;10(18):e2300792. doi: 10.1002/advs.202300792. Epub 2023 Apr 21.
Electrostatic capacitors attract great interest in energy storage fields due to their advantages of high power-density, fast charge/discharge speed, and great reliability. Intensive efforts have been placed on the development of high-energy-density of capacitors. Herein, a novel supercapacitor with Hf Zr O /xAl O /Hf Zr O (HAHx) is designed to improve the breakdown strength (E ) through optimizing Al O (AO) film thickness. Low-temperature annealing is first proposed to enhance the polarization difference (P -P ) due to the formation of dispersed polar nanoregions, which is called "superparaelectric-like" similar to previous super-paraelectric behavior of perovskite structures. As results, both large E and P -P values are obtained, leading to an ultrahigh energy storage density of 87.66 J cm with a high efficiency of 68.6%, as well as a reliable endurance of 10 cycles. This work provides a feasible pathway to improve both the polarization difference and breakdown strength of HfO -based films by the combination of insulation insertion layer and low-temperature annealing. The proposed strategy can contribute to the realization of high-performance electrostatic supercapacitors with excellent microsystem compatibility.
静电电容器因其高功率密度、快速充放电速度和高可靠性等优点，在储能领域引起了极大的兴趣。人们一直在努力提高电容器的能量密度。本文设计了一种新型的 HfZrO/xAl2O3/HfZrO（HAHx）超级电容器，通过优化 Al2O3（AO）薄膜厚度来提高击穿强度（E）。首先提出低温退火，通过形成分散的极性纳米区来增强极化差（P-P），这被称为“类超顺电”，类似于之前钙钛矿结构的超顺电行为。结果，获得了大的 E 和 P-P 值，从而实现了超高的储能密度 87.66 J cm，效率为 68.6%，以及可靠的 10 次循环耐久性。这项工作通过绝缘插入层和低温退火相结合，为提高基于 HfO2 的薄膜的极化差和击穿强度提供了一种可行的途径。所提出的策略有助于实现具有优异微系统兼容性的高性能静电超级电容器。
