Gao Yangfei, Song Zizheng, Hu Haichao, Mei Junwen, Kang Ruirui, Zhu Xiaopei, Yang Bian, Shao Jinyou, Chen Zibin, Li Fei, Zhang Shujun, Lou Xiaojie
Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, and Xi'an Key Laboratory of Electric Devices and Materials Chemistry, Xi'an Jiaotong University, Xi'an, China.
Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Nat Commun. 2024 Jul 12;15(1):5869. doi: 10.1038/s41467-024-50252-w.
As a vital material utilized in energy storage capacitors, dielectric ceramics have widespread applications in high-power pulse devices. However, the development of dielectric ceramics with both high energy density and efficiency at high temperatures poses a significant challenge. In this study, we employ high-entropy strategy and band gap engineering to enhance the energy storage performance in tetragonal tungsten bronze-structured dielectric ceramics. The high-entropy strategy fosters cation disorder and disrupts long-range ordering, consequently regulating relaxation behavior. Simultaneously, the reduction in grain size, elevation of conductivity activation energy, and increase in band gap collectively bolster the breakdown electric strength. This cascade effect results in outstanding energy storage performance, ultimately achieving a recoverable energy density of 8.9 J cm and an efficiency of 93% in BaSrCaNbTaO ceramics, which also exhibit superior temperature stability across a broad temperature range up to 180 °C and excellent cycling reliability up to 10. This research presents an effective method for designing tetragonal tungsten bronze dielectric ceramics with ultra-high comprehensive energy storage performance.
作为储能电容器中使用的重要材料，介电陶瓷在高功率脉冲装置中有着广泛的应用。然而，开发兼具高能量密度和高温下效率的介电陶瓷面临着重大挑战。在本研究中，我们采用高熵策略和带隙工程来提高四方钨青铜结构介电陶瓷的储能性能。高熵策略促进阳离子无序并破坏长程有序，从而调节弛豫行为。同时，晶粒尺寸的减小、电导率激活能的提高以及带隙的增加共同提高了击穿电场强度。这种级联效应导致了出色的储能性能，最终在BaSrCaNbTaO陶瓷中实现了8.9 J/cm的可恢复能量密度和93%的效率，该陶瓷在高达180°C的宽温度范围内还表现出优异的温度稳定性以及高达10次的出色循环可靠性。本研究提出了一种设计具有超高综合储能性能的四方钨青铜介电陶瓷的有效方法。
