Boosting Energy Storage Performance of Glass Ceramics via Modulating Defect Formation During Crystallization.

Along with the demand for further miniaturization of high and pulsed power devices, it becomes more and more important to realize ultrahigh recoverable energy storage density (Wrec ) with high energy storage efficiency (η) and ultrahigh discharge energy storage density (Wd ) accompanied by high power density (Pd ) in dielectrics. To date, it remains, however, a big challenge to achieve high Wrec or Wd in glass ceramics compared to other dielectric energy storage materials. Herein, a strategy of defect formation modulation is applied to form "amorphous-disordered-ordered" microstructure in BaTiO3 -based glass ceramics so as to achieve a high Wrec of 12.04 J cm-3 with a high η of 81.1% and an ultrahigh Wd of 11.98 J cm-3 with a superb Pd of 973 MW cm-3 . This work demonstrates a feasible route to obtain glass ceramics with an outstanding energy storage performance and proves the enormous potential of glass ceramics in high and pulsed power applications.

Glass-Ceramic Capacitors with Simultaneously High Power and Energy Densities under Practical Charge-Discharge Conditions.

Developing dielectric capacitors with both a high power density and a high energy density for application in power electronics has been a long-standing challenge. Glass-ceramics offer the potential of retaining the high relative permittivity of ceramics and at the same time of exhibiting the high dielectric breakdown strength and fast charge/discharge rate of glasses, thus producing concurrently high power and energy densities in a single material. In this work, glass-ceramics are fabricated to achieve simultaneously high power and energy densities, high efficiency, and thermal stability by tuning the glass crystallization process via a suitable nucleating agent and a high oxygen partial pressure. Under the same practical charge-discharge test conditions, the as-prepared glass-ceramics combine the high energy density of ceramics and ultrafast discharge rate of glasses, producing the highest power density among glass- and ceramic-based dielectric materials. This work demonstrates the significant potential of achieving both high power and energy densities in glass-ceramics by optimizing the glass crystallization process.