Xiafeng He, Jian Wang, Yuxiao Du, Kun Zhao, Dongliang Shan, Yunya Liu, Chao Xu, Zhenyong Cen, Xiaoyi Gao, Rui Huang, Xiyong Chen, Zhonghui Shen, Dawei Wang, Limei Zheng, Haibo Zhang, Jing‐Feng Li, Shujun Zhang, Nengneng Luo
ABSTRACT Achieving both high energy storage density and excellent thermal stability in lead‐free multilayer ceramic capacitors (MLCCs) has long been a critical challenge for advanced electronic systems. To address this issue, we propose an innovative strategy to simultaneously improve both properties by constructing ordered heterogeneous interfaces through embedding parallel‐aligned Al 2 O 3 plates in 0.6SrTiO 3 ‐0.4Bi 0.5 Na 0.5 TiO 3 (0.6ST‐0.4BNT) lead‐free ceramics. This approach effectively suppresses the charge carrier injection and transport, yielding an ultrahigh recoverable energy storage density of 16.0 J cm −3 with a giant breakdown strength of 1140 kV cm −1 in Al 2 O 3 modified 0.6ST‐0.4BNT based MLCCs, which outperforms most state‐of‐the‐art dielectric ceramics. Furthermore, the MLCCs exhibit superior thermal stability with variation less than 3% across a broad temperature range of 20–160 °C. The overall superior performance underscores the potential of the ordered heterogeneous interface engineering in advancing the thermally stable high‐density energy storage materials for next‐generation MLCC applications.