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Bi0.5Na0.5TiO3‐based ceramics with high remnant polarization Pr have shown outstanding potential in the application of high‐power ferroelectric transducers. However, low depolarization temperature Td is an obstacle for their application. Here, a composition design strategy was proposed to simultaneously improve the Td and Pr in BNT‐based materials. Ultrahigh Pr of 40.56 µC/cm2 and relative high Td of 184°C were synergistically achieved in (Bi0.5Na0.5)(Ti0.995Mn0.005)O3 (BNMT) ceramics by adding 1.0 mol% BiGaO3 (BG), which is superior to other reported lead‐free systems. The excellent ferroelectric properties were attributed to strengthen ferroelectric order as evidenced by increased rhombohedral distortion. Meanwhile, the enhanced depolarization temperature, increasing from 168°C for x = 0% to 184°C for x = 1.0%, can be ascribed to the suppression of the thermal‐induced ferroelectric‐relaxor phase transition by adding BG. Those results enable the BNMT‐BG systems ceramics to be an attractive candidate for application in high‐power supplies. [ABSTRACT FROM AUTHOR]

Although KNN‐based ceramics with high electrical properties are obtained through a variety of strategies, the temperature sensitivity is still one of the key technical bottlenecks hindering practical applications. Here, we use a new strategy, meticulously tailoring phase boundary, to refine the ferroelectric boundary of KNN‐based ceramics, leading to high piezoelectricity companied with improving temperature stability. The highest d33 value in this system reaches 501 pC/N with a TC ∼ 240°C, whereas a large strain of ∼0.134% can be kept with 10% lower deterioration until 100°C. The origin of high piezoelectricity is mainly attributed to the well‐preserved multiphase coexistence and the appearance of nanodomains, which greatly facilitate the polarization rotation. Instead of the changed intrinsic thermal insensitivity, the precision phase boundary engineering plays an important role in strengthening the temperature stability of electric‐induced strain. This work provides a simple and effective method to obtain both high electrical properties and excellent thermal stability in KNN‐based ceramics, which is expected to promote the practical applications in the future. [ABSTRACT FROM AUTHOR]