Energy storage mechanism and refinement engineering of SiO2-B2O3-Nb2O5 complex glass-ceramic doped with La2O3

Rare earth doping has demonstrated promising potential in improving material properties. This paper explored the influence mechanism of La ₂O ₃ on SiO ₂-B ₂O ₃-Nb ₂O ₅ (SBN) system energy storage glass-ceramic. The results reveal a significant impact of La ₂O ₃ doping on the physical properties, microstructure, and energy storage performance. Firstly, we observed the influences on the breakdown field strength through its effect on the grain size, density, and conductivity. The larger radius of La ³⁺ triggers lattice vibrations, leading to a reduction in grain size and an increase in density. Moreover, the electronic shielding effect of the 4f layer reduces conductivity, which subsequently enhances the breakdown resistance. The dielectric constant exhibits improvements due to La ₂O ₃ doping. Increased crystallinity and polarization strength, along with the f-f transition of La ³⁺ and reduced domain area, result in a peak dielectric constant at L4. Consequently, the energy storage performance is enhanced.