Strong Lead‐Free Bioinspired Piezoceramics for Durable Energy Transducers

ABSTRACT Durable, high‐performance, and environmentally friendly lead‐free piezoceramics are essential for next‐generation sustainable energy transducers and electromechanical systems. However, piezoceramics are mechanically weak, which negatively impacts their working conditions and durability. A solution to improve their mechanical durability without sacrificing piezoelectric performance remains elusive. Here, we design a bioinspired brick‐and‐mortar Bi 0.5 Na 0.5 TiO 3 (BNT) ceramics with BNT bricks and silica mortar. This deliberate microstructure design yields a 2.8‐fold, from 104 to 294 MPa, increase in strength and 2‐fold, from 0.9 to 1.8 MPa·m 0.5 , increase in fracture toughness compared with conventional BNT without sacrificing piezoelectric performance. These improvements translate into a 110‐fold increase in ferroelectric fatigue lifetime and a 37% higher voltage output and slower degradation as energy transducers. These gains originate from anisotropic residual stress fields, revealed by Raman and XRD, which delay crack initiation events. Given its microstructural origin, this strategy is broadly applicable to other systems where both functional and structural performance are critical.