Giant Energy Density via Mechanically Tailored Relaxor Ferroelectric Behavior of PZT Thick Film

Abstract Relaxor ferroelectrics (RFEs) are being actively investigated for energy‐storage applications due to their large electric‐field‐induced polarization with slim hysteresis and fast energy charging–discharging capability. Here, a novel nanograin engineering approach based upon high kinetic energy deposition is reported, for mechanically inducing the RFE behavior in a normal ferroelectric Pb(Zr 0.52 Ti 0.48 )O 3 (PZT), which results in simultaneous enhancement in the dielectric breakdown strength ( E DBS ) and polarization. Mechanically transformed relaxor thick films with 4 µm thickness exhibit an exceptional E DBS of 540 MV m −1 and reduced hysteresis with large unsaturated polarization (103.6 µC cm −2 ), resulting in a record high energy‐storage density of 124.1 J cm −3 and a power density of 64.5 MW cm −3 . This fundamental advancement is correlated with the generalized nanostructure design that comprises nanocrystalline phases embedded within the amorphous matrix. Microstructure‐tailored ferroelectric behavior overcomes the limitations imposed by traditional compositional design methods and provides a feasible pathway for realization of high‐performance energy‐storage materials.