Glass ceramics composed of Na2O-BaO-Bi2O3-Nb2O5-Al2O3-SiO2 (NBBN-AS) were modified by rare-earth doping and prepared via the melt-quenching process accompanied by controlled crystallization. High-resolution transmission electron microscopy displayed the glassy matrix closely encompassing the nanosized NaNbO3, Ba2NaNb5O15, BaAl2Si2O8, and AlNbO4 crystalline grains. With rare-earth doping, the NBBN-AS glass ceramics' theoretical energy storage density can reach 22.48 J/cm3. This excellent energy storage property is credited with increasing breakdown strength, and numerical simulation was applied to reveal the intrinsic mechanism for increased breakdown strength by rare-earth doping. The charge-discharge results indicated a giant power density of 220 MW/cm3 as well as an ultrafast discharge speed of 11 ns. The results indicate that the glass ceramic can be used in advanced capacitor applications.
Keywords: discharge speed; energy storage capacitors; glass ceramics; numerical simulation; power density.