Engineering nanocluster and pyrochlore phase in BiFeO3-based ceramics for electrostatic energy storage

BiFeO3, known for its exceptional spontaneous polarization and high Curie temperature, stands as a pivotal component in power electronics. However, its relatively low breakdown strength has been a bottleneck in improving energy storage performance. Herein, we present an innovative approach to constructing nanoclusters and pyrochlore phases within BiFeO3-based ceramics. Specifically, the integration of the pyrochlore phase and nanoclusters (less than 10 nm) effectively reduces grain size and extends the growth path of electric trees, while imbuing the material with relaxor properties, which contribute to a significant enhancement in breakdown strength. As a result, this method achieves an ultrahigh energy storage density of 7.2 J/cm(3) under 800 kV/cm, coupled with remarkable stability of temperature (20-180 degrees C), frequency (1-500 Hz), and fatigue resistance (over 10, 000 cycles). This work provides a viable pathway for the development of dielectric materials with superior energy storage performance to meet the stringent demands of advanced capacitor applications.