Investigation of structure, dielectric and energy-storage properties of lead-free niobate glass and glass-ceramics

Lead-free glass and glass-ceramics in Na2O-BaO-Nb2O5-SiO2 (mol%) system were successfully synthesized. The tailoring effect of crystallization temperature on the structural, dielectric, and energy storage properties of the material system was investigated. Two types of nano-sized crystalline phases of Ba2NaNb5O15 and NaNbO3 were formed in succession in the crystallization temperature range from 700 °C to 1000 °C. The crystallinity and size of the crystallites were increased with the increasing crystallization temperature. The dielectric constant demonstrated good thermal and frequent stability. The loss tangent was well controlled below 0.035. At electric field of 10 kV/mm, the highest charged energy density and discharged energy density reached 0.19 J/cm3 and 0.17 J/cm3 respectively in the glass-ceramic crystallized at 1000 °C, indicating the excellent energy storage properties could be tailored by controlling the crystallization temperature.