Broadening the dielectric stability temperature range of BNBST relaxor ferroelectric ceramics by rare earth Ce doping for energy storage

(Bi_0.5Na_0.5)_0.65(Ba_0.3Sr_0.7)_0.35Ti_1-XCe_XO₃ (abbreviated as BNBSTC_100x, x = 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08) ceramics were prepared by a solid-state reaction method. The effect of rare earth Ce-doping content on the phase structure, microstructure, dielectric properties and energy storage characteristics of ceramics was investigated. All BNBSTC_100x ceramics had a single pseudocubic perovskite structure with high bulk density. With the increase of Ce-doping content, the dielectric peak of BNBSTC_100x ceramics was gradually suppressed and flattened, which effectively broadened the dielectric stability temperature range. Meanwhile, the P-E hysteresis loop of the ceramics gradually changed to slim with Ce content, and the optimized energy storage properties were achieved in BNBSTC₄ ceramics with recoverable energy storage density W_rec = 1.15 J/cm³ and efficiency η = 81% under a relatively low electric field of 100 kV/cm. Furthermore, the BNBSTC₄ ceramics also exhibited good temperature, frequency and fatigue cycle stability, which should be a good candidate ceramic material for pulse power capacitors used in a wider temperature range.