Effective strategy to realise excellent energy storage performances in lead-free barium titanate-based relaxor ferroelectric

Abstract High-performance capacitors, which possess a high energy storage density, large power density and fast charge/discharge rate, are in high demand in pulsed power systems. Although several studies have been conducted to obtain excellent energy storage performances, the scientific and feasible guidance is lacking on how to quickly and efficiently find a material system with high recoverable energy storage density (Wrec), large energy storage efficiency (η), and excellent thermal stability. Herein, a strategy is proposed to concurrently regulate the temperature corresponding to the maximum dielectric constant (Tm) to around room temperature and enhance the relaxor characteristic. To our satisfaction, excellent energy storage performances with a high Wrec of 3.05 J/cm3, large η of 95%, and wide temperature stability (20–180 °C) were achieved in 0.85BaTiO3-0.15Bi(Mg05Sn0.5)O3 (0.15BMS) ceramics. In addition, these ceramics also exhibited a large discharge energy density (Wdis = 0.74 J/cm3) and fast discharge time (t0.9 = 105 ns) over a broad temperature range (20–180 °C), which confirms their significant application potential in the high-temperature field. These results indicate that this work can provide an effective guideline approach to attain high-performance capacitors for application in pulsed power capacitors.