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

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 Al₂O₃ plates in 0.6SrTiO₃-0.4Bi_0.5Na_0.5TiO₃ (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 Al₂O₃ 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.