Optimizing dielectric energy storage properties of BNT-based relaxor ferroelectric ceramics modified via Ba_0.4Sr_0.6TiO₃

Low-voltage driven ceramic capacitor applications call for relaxor ferroelectric ceramics with superior dielectric energy storage capabilities. Here, the (Bi_0.5Na_0.5)_0.65(Ba_0.3Sr_0.7)_0.35(Ti_0.98Ce_0.02)O₃ + x wt% Ba_0.4Sr_0.6TiO₃ (BNBSTC + xBST, x = 0, 2, 4, 6, 8, 10) ceramics were prepared to systematically investigate the effect of BST content on the phase structure, microscopic morphology and dielectric energy storage properties. A single perovskite structure with a dense and homogenous microstructure is presented in all BNBSTC + xBST ceramics. A recoverable energy storage density W_rec = 1.39 J/cm³ with efficiency η = 81.5% is achieved only under a low electric field of 94 kV/cm in the optimal composition of x = 6, accompanied by an enhanced dielectric temperature stability meeting the requirement of wider working window. In addition to good frequency, anti-fatigue and temperature stability, the BNBSTC + 6BST ceramics exhibit tremendous potential for designing low-voltage driven energy storage ceramic capacitors.