Improving the energy storage performance of BaTiO₃-based glass ceramics by reconstituting glass network structure via electronegativity tuning

Developing dielectric capacitors with both excellent recoverable energy storage density (W_rec) and high dielectric breakdown strength (DBS) are highly desired for pulsed power electronic systems. Although glass ceramics are known to potentially possess simultaneously a high DBS and a relatively high dielectric constant (ε_r), it is still a long-standing challenge to obtain high energy storage performance in glass ceramics. In this work, based on the consideration of electronegativity and its effects on the degree of polymerization, SnO₂ addictive was introduced to reconstitute the parent glass network structure and thereby an ultra-high DBS value of 2809 kV/cm was achieved in the SnO₂-doped parent glass. After crystallization of the SnO₂-doped parent glass, an ultrahigh W_rec of 10.13 J/cm³ with an efficiency (η) of 85.5% and a superb discharge energy storage density (W_d) of 9.09 J/cm³ at 1500 kV/cm were obtained in the BaTiO₃-based glass ceramic. Meanwhile, this BaTiO₃-based glass ceramic displays a good thermal stability over a wide temperature range of 30–120 °C, with the W_rec only decreasing by 3.0% and W_d dropping from 4.40 J/cm³ to 3.53 J/cm³ at 800 kV/cm. Furthermore, it also exhibits high optical transmittance (about 60%) in the visible light spectrum. These features indicate that the BaTiO₃-based glass ceramic studied in this work has a great potential not only for high-pulsed power applications but also for optical applications, making it a truly multifunctional material.