Work

Entropy-driven multi-scale enhancement of energy storage performance in (Bi0.5Na0.5)0.5Ba0.5TiO3 ceramics

Year: 2025

Type: article

Abstract: The dielectric ceramic capacitor serves as the core energy storage element in the pulsed power system. However, the inability to balance high energy storage density ( W rec ) and energy storage efficiency ( η ) has become a technical challenge limiting the miniaturisation of pulsed power devices. This work proposes an entropy-driven strategy, through introducing Sr(Sc 0.5 Nb 0.5 )O 3 (SSN) as an end-member, to modulate the phase structure and suppress interfacial polarization in the medium entropy matrix, (Bi 0.5 Na 0.5 ) 0.5 Ba 0.5 TiO 3 (BN50BT). The introduction of SSN endows BN50BT ceramics with a multiphase structure of P 4 mm and Pm 3 ¯ m and successfully establishes a super-paraelectric (SPE) state at room temperature, improving the polarization response. Furthermore, the incorporation of SSN effectively suppresses interfacial polarization and enhances the E b of the system. Thus, the 0.80 [(Bi 0.5 Na 0.5 ) 0.5 Ba 0.5 TiO 3 ]-0.20Sr(Sc 0.5 Nb 0.5 )O 3 ceramics exhibit a decent W rec of 6.24 J/cm 3 and a high η of 89.02%, along with remarkable stabilities over a wide frequency range (5–150 Hz) and temperature range (25–140 °C). This work demonstrates that the entropy-driven construction of a multiphase-coexisting SPE state, along with suppressed interfacial polarization, represents a feasible approach to optimizing the energy storage properties of dielectric ceramics. • Entropy-driven successful construction of a superparaelectric state with multi-phase coexistence, leading to an increased Δ P. • Entropy-driven suppression of interfacial polarization significantly enhances E b . • High W rec of 6.24 J/cm 3 and η of 89.02 % are achieved in the BN50BT-20SSN ceramic. • Optimal ceramics possess excellent frequency and temperature stabilities.

Source: Journal of Materiomics

DOI: 10.1016/j.jmat.2025.101055