Ultrahigh energy storage density and instantaneous discharge power density in BaO–PbO–Na2O–Nb2O5–SiO2–Al2O3 glass-ceramics

Abstract

Compared with traditional dielectric materials, ferroelectric glass-ceramic capacitors have higher energy storage densities and faster discharge speeds. In this study, 21.6BaO–2.4PbO–6Na₂O–30Nb₂O₅–10Al₂O₃–30SiO₂ glass-ceramics and their single-layer capacitors were successfully prepared. A maximum energy storage density of 20.7 J cm⁻³ was obtained in these glass-ceramics. For glass-ceramics capacitors crystallized at 900 °C, under an electric field of 400 kV cm⁻¹, the maximum instantaneous power density reached was 78.2 MW cm⁻³ and the discharge time was <35 ns. The effects of crystallization temperature on dielectric energy storage properties were illustrated by investigating the crystallization kinetics, phase evolution, and microstructure of these glass-ceramics. The crystallization process was mainly affected by the bonding strengths of Si–O and Al–O. When the crystallization temperature increased from 850 to 1000 °C, crystallinity increased from 64.5 to 97.3%, Ba₂NaNb₅O₁₅ and NaNbO₃ were precipitated in all samples, and microstructural pores and microcracks gradually appeared. All the results showed that these materials were promising candidates for application in pulse capacitors.