High-entropy engineered BaTiO₃-based ceramic capacitors with greatly enhanced high-temperature energy storage performance

Ceramic capacitors with ultrahigh power density are crucial in modern electrical applications, especially under high-temperature conditions. However, the relatively low energy density limits their application scope and hinders device miniaturization and integration. In this work, we present a high-entropy BaTiO₃-based relaxor ceramic with outstanding energy storage properties, achieving a substantial recoverable energy density of 10.9 J/cm³ and a superior energy efficiency of 93% at applied electric field of 720 kV/cm. Of particular importance is that the studied high-entropy composition exhibits excellent energy storage performance across a wide temperature range of −50 to 260 °C, with variation below 9%, additionally, it demonstrates great cycling reliability at 450 kV/cm and 200 °C up to 10⁶ cycles. Electrical and in-situ structural characterizations revealed that the high-entropy engineered local structures are highly stable under varying temperature and electric fields, leading to superior energy storage performance. This study provides a good paradigm of the efficacy of the high-entropy engineering for developing high-performance dielectric capacitors.