Boosting energy-storage performance in lead-free ceramics via polyphase engineering in the superparaelectric state
Publication Name
Composites Part B: Engineering
Abstract
Dielectric energy storage devices are important components of high-power and pulsed electronic systems. High recoverable energy density (Wrec) and high efficiency (ƞ) are critical parameters for such applications. In this work we propose a strategy of polyphase engineering in the superparaelectric (SPE) state to achieve high-performance energy storage. Through careful engineering of the proportions of rhombic (R) phase and tetragonal (T) phase by a linear dielectric additive, CaTi0.8Hf0.2O3 (CTH), in 0.94Na0.5Bi0.5TiO3-0.06BaTiO3-based ceramics, the SPE state can be shifted to ambient temperature when R/T ≤ 0.16. Thanks to the features of isolated polar nano-domains (PNRs) and the fine P-E hysteresis loop of the SPE state, an ultrahigh Wrec of 8.91 J/cm3 and high ƞ of 78.4% are achieved in our 0.75(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.25CaTi0.8Hf0.2O3 sample. The sample was also characterized by excellent temperature and frequency stability, achieving ultra-high power density (178 MW/cm3) and ultra-fast transient discharge time (40 ns). Our work proves that polyphase engineering in the SPE state is a powerful approach to the design of dielectric energy storage materials with high performance.
Open Access Status
This publication is not available as open access
Volume
255
Article Number
110630
Funding Number
11874394
Funding Sponsor
National Natural Science Foundation of China