Ordered Heterogeneous Interfaces Enable Temperature‐Insensitive and Ultrahigh‐Energy‐Storage Multilayer Ceramic Capacitors

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.