@article{Zhang2025, 
author = {Xinle Zhang and Shimin Sun and Chao Yin and Yue Zhang and Changhai Zhang and Tiandong Zhang and Qingguo Chi},
title = {Giant recoverable energy storage density for lead-free SrTiO3-based dielectric films coated by the amorphous Al2O3 insulating layers},
year = {2025},
journal = {Journal of Advanced Ceramics},
volume = {14},
number = {11},
pages = {9221175},
keywords = {dielectric, energy storage, breakdown strength, multilayer, strontium titanate (SrTiO3)},
url = {https://www.sciopen.com/article/10.26599/JAC.2025.9221175},
doi = {10.26599/JAC.2025.9221175},
abstract = {SrTiO3 paraelectric materials, characterized by their linear polarization behavior, low polarization loss, and lead-free composition, are promising candidates for environmentally friendly energy storage dielectrics. However, their energy storage capabilities are limited by low breakdown field strength and polarization intensity. This work proposes a design strategy involving insulator‒paraelectric heterojunction multilayers by incorporating amorphous Al2O3 (AO) insulating layers into SrTi0.99Mn0.01O3 (STM) thin films. By adjusting the number and spatial placement of the Al2O3 insulating layers, the effects of the Al2O3 layers on the microstructure and energy storage performance of the STM films were revealed. The results demonstrate that the AO/STM/AO top‒bottom configuration exploits the synergistic effects of electrode interface barriers and the built-in electric field (Ein) within the heterojunction to create a full-path charge transport barrier. This arrangement significantly enhances the breakdown strength and reduces conduction losses. The optimized composite film exhibited a breakdown field strength of 6467 kV/cm and a very large recoverable energy storage density of 73.33 J/cm3, with an energy storage efficiency of 80.17%, outperforming existing SrTiO3-based energy storage materials. Furthermore, the composite film demonstrated excellent stability across a wide temperature range (20–250 °C), a broad frequency band (0.2–10 kHz), and high-frequency switch cycles (107 cycles).}
}