Enhancing energy storage performance in tungsten bronze ceramics utilizing site engineering

Advanced electronic systems and innovative pulsed power applications are driving the rapid development of high-energy-storage density and high-efficiency capacitors. In the present study, we have prepared SrBa_3.5Sm_0.5R_0.5Nb_9.5O₃₀ (R = Mn, Ti, Sn, Hf) (henceforth referred to as SBSRN) ceramics by solid-phase synthesis, using a site engineering strategy that utilizes tetravalent ions for the substitution of Nb⁵⁺ at the B-site of tetragonal phase tungsten bronzes. SBSRN ceramics benefit from site engineering strategies to enhance overall energy storage performance. As a result, they achieve a substantial energy storage density of 4.31 J·cm^-3 and an impressive efficiency of 91.3% when subjected to an electric field of 340 kV·cm^-1, and show excellent stability in ferroelectric performances with variable temperature and frequency. In addition, these ceramics have a large discharge energy density of 2.68 J·cm^-3 and a fast discharge time of 62 ns in charge/discharge tests, along with a current density of 619.96 Acm^-2 and a power density of 65.1 MWcm^-3. In summary, this research offers a promising method for developing energy storage materials that hold potential for innovative applications in pulsed power components.