Room temperature superparaelectric state in 20BaTiO${}_3$-60 V${}_2$O${}_5$-20 Bi${}_2$O${}_3$ glass for capacitive energy storage applications

Materials with high dielectric constant exhibit excellent charge storage capacity, making them favorable solutions for next-generation dielectric capacitors. The glass system with the composition of 20BaTiO${}_3$-60 V${}_2$O${}_5$-20 Bi${}_2$O${}_3$ was prepared by conventional melt quenching technique. The glassy nature of the sample was confirmed by using DSC and XRD measurement while the existence of nano polar cluster inside the glass matrix was confirmed using HRTEM. The real permittivity (${\epsilon }^{\prime }$) value shows two peaks in which the dielectric constant gradually increases up to a maximum value (${\epsilon }_m$) with the increase in temperature, and then it smoothly decreases, suggesting two phase transitions around 180 and 280 °C. The measurements of the P-E hysteresis loop illustrated energy storage density of 124 mJ/cm${}^3$ and energy storage efficiency about 84% at room temperature. The glass sample shows superparaelectric behavior confirmed by the dielectric and P-E loop measurements. For high-energy storage applications, dipolar glasses have more outstanding potential than conventional ceramic dielectrics. Eventually, the glass matrix maintains high breakdown strength and can effectively stabilize nanocluster phases. So, we consider the present glass sample to be a good candidate for capacitive energy storage applications.