Dielectric properties and charge-discharge behaviors in niobate glass ceramics for energy-storage applications

A series of niobate glass ceramics with varying glass content have been prepared via controlled-crystallization route, and the dielectric properties, the breakdown characteristics and charge-discharge behaviors have been investigated. The correlation between the dielectric breakdown performance and the activation energy was studied by the measurements of the dielectric breakdown strength and impedance spectroscopy. The charge-discharge efficiency was investigated using a charge-discharge system with high-speed capacitor discharge circuit device. It was found that the dielectric breakdown strength and the discharge efficiency strongly depend on the interface polarization based on the results of complex impedance analysis. With the increase of the glass content, the breakdown strength (BDS) and the charge-discharge efficiency show a clear increasing trend, when the content of glass was 60%, the typical G60 sample shows a high BDS of 1300 kV/cm and a high charge-discharge efficiency of 92.5%.