A novel Sr5BiTi3Nb7O tungsten bronze ceramic with high energy density and efficiency for dielectric capacitor applications

Dielectric capacitors with high capacitive energy storage are urgently needed to meet the growing demand for high-performance energy storage devices. Herein, a novel lead-free Sr5BiTi3Nb7O[Formula: see text] (SBTN) tungsten bronze relaxor ferroelectric ceramic is prepared and explored for potential energy storage applications. A high recoverable energy density [Formula: see text] ([Formula: see text] 3.72 J/cm3) and ultrahigh efficiency [Formula: see text] ([Formula: see text] 94.2%) at 380 kV/cm are achieved simultaneously. Both [Formula: see text] and [Formula: see text] exhibit superior stabilities against temperature (30–140[Formula: see text]C), cycles (100 –105) and frequency (1–500 Hz). In addition, a high current density of 796 A/cm2 and a large power density of 71.7 MW/cm3 are achieved, together with good thermal endurance and fatigue resistance. These results demonstrate that the obtained SBTN ceramic can be deemed as the promising candidates for dielectric capacitor applications