Enhanced energy-storage properties in bismuth sodium titanate-strontium titanate ceramics by doping calcium zirconate linear perovskite

Next-generation high-power capacitors depend on environmentally acceptable, lead-free dielectric ceramics with ultrahigh energy storage capability, but this is a difficult task. The solid-state reaction is harnessed here to create bismuth sodium titanate-strontium titanate-calcium zirconate ceramics (1-x (0.76Bi_0.5Na_0.5TiO₃-0.24SrTiO₃)-xCaZrO₃, abbreviated as BNST-100xCZ, x = 0, 0.02, 0.04, 0.06, 0.08). It has been demonstrated that doping the BNST matrix with CZ increases relaxor behavior, decreases grain size, and widens the band gap, all of which increase breakdown strength and postpone polarization saturation. The BNST-6CZ ceramics showed a recovered energy density (W_rec) of 1.83 J/cm³ and an energy storage efficiency (η) of 84.15 %. Furthermore, it demonstrated outstanding cycling performance for energy storage. The material also demonstrated higher resistivity, lower oxygen vacancy concentration, and superior dielectric temperature stability across a wide temperature range from 65 °C to over 400 °C. These results suggest that BNST-100xCZ ceramics hold great prospects for energy storage devices and actuators.