The inferior temperature stability of piezoelectric response is the main drawback of KNN-based ceramics. Here, the Ba-doped 0.97(K_0.48Na_0.52)(Nb_0.96Sb_0.04)O₃-0.03Ba_x(Bi_0.5Ag_0.5)_1-xZrO₃ (abbreviated as KNNS-BBAZ) textured ceramics were prepared by the template grain growth (TGG) method. Excellent comprehensive properties (d₃₃=(406 ± 15) pC/N, T_C = 274 ℃, strain is 0.17%) were achieved in KNNS-BBAZ textured ceramics with x = 0.2. Meanwhile, its piezoelectric and strain properties also show superior temperature stability (d₃₃ maintained within ±20% change in a wide temperature range from 25 ℃ to 200 ℃ and strain variation was less than 5% in the temperature range from room temperature to 165 ℃). The high O-T phase transition temperature (T_O-T is 110 ℃) induced by incorporating Ba ions accounts for the enhanced temperature stability of piezoelectric properties. In addition, the crystal texture always maintains the contribution of piezoelectric anisotropy to the piezoelectric properties during elevated temperature, which significantly improved the temperature stability of piezoelectric properties. This work provides an effective strategy for simultaneously achieving high piezoelectric response and excellent temperature stability in KNN-based ceramics.

For glass-ceramics, how to realize the collaborative optimization of BDS and permittivity is the key to improve the energy storage density. In this work, ZrO₂ is introduced into BPKNAS glass-ceramics as nucleating agent to promote crystal development of glass-ceramics and then achieve high permittivity. When 1.5 mol% ZrO₂ is added, the glass-ceramics have the highest permittivity (~128.59) and meanwhile possess high BDS (1948.90 kV/cm) due to the dense microstructure. Therefore, BPKNAS-1.5ZrO₂ glass-ceramics has the highest theoretical energy storage density (21.62 J/cm³). Moreover, the permittivity variation of BPKNAS-1.5ZrO₂ glass-ceramics is less than 6 % in the wide temperature range from −80 to 300 ℃, showing excellent temperature stability. In addition, BPKNAS-1.5ZrO₂ glass-ceramics possesses ultrahigh power density, which reaches up to 382.40 MW/cm³ in overdamped circuit. The above evidence shows that BPKNAS-1.5ZrO₂ glass-ceramics with ultrahigh energy storage density and power density is very competitive in the field of energy storage applications.