Effect of analogue nucleating agent on the interface polarization and energy-storage performance of NaNbO3-based glass-ceramics

NaNbO3-based glass-ceramics have garnered considerable attention owing to their high dielectric constant (epsilon r), low dielectric loss (tan delta), excellent chemical stability and tunable dielectric properties. Nonetheless, one major obstacle restricting the applications of NaNbO3-based glass-ceramics in energy-storage capacitors is their low breakdown strength (BDS) caused by interface polarization. In this work, the grains of glass-ceramics turn into fine and uniform from agglomeration via adding nucleating agent analogue HfO2 to Na2O-Nb2O5-CaO-SiO2-B2O3 (NNCBS-H) glass matrix. Thus, the long-range migration of space charge is frozen by the refined grains, which is conducive to diminishing the interfacial polarization of glass-ceramics. Moreover, the band gap energy (E-g) of NNCBS-H glass-ceramics elevates from 3.21 eV to 3.30 eV with the incorporation of HfO2 with wide band gap, enhancing its insulating performance. Ultimately, NNCBS-H4 glass-ceramics achieve a remarkable energy storage density (W-rec) of 3.8 J/cm(3), establishing an effective approach and precedent for developing glass-ceramic materials with high energy storage properties.