Composition-driven (Bi_(0.5)Na_(0.5))TiO_3-based ceramics as novel high-performance energy storage materials for capacitor applications

摘要

The ability of storing electrostatic energy for a capacitor is largely dependent on the energy storage performances of the material used in the electronic components. In this case, a composition-driven Bi_(0.5)Na_(0.5)TiO_3-based system, (1-x)(0.84Bi_(0.5)Na_(0.5)TiO_3-0.16Bi_(0.5)K_(0.5)TiO_3)-xBi(Mg_(0.5)Ti_(0.5))O_3 (NTB-KBT-10OxBMT, x = 0.04-0.14) was designed and the enhanced energy storage density and efficiency with good thermal insensitivity were confirmed. The introduction of BMT can induce the relaxor characteristic due to the deconstruction of the ferroelectric long-range order, leading to the increase in dielectric breakdown and the improved energy storage performances. Particularly, the NTB-KBT-8BMT ceramic exhibits a high stored energy density (W_(total) = 2.88 J/cm~3) and recoverable energy density (W_(rec) = 2.42 J/cm~3) with good energy efficiency (η = 84.0%) under 320 kV/cm, indicative of potential application for energy storage components. Moreover, the NTB-KBT-8BMT ceramic exhibits typical temperature-independent character in a wide temperature range from 30 to 140 °C due to broad diffused phase transition. It can be concluded that constructing relaxor ferroelectrics is an effective approach to design novel dielectrics for pulse power applications.