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

초록

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(Zr0.52Ti0.48)O3 (PZT), which results in simultaneous enhancement in the dielectric breakdown strength (EDBS) and polarization. Mechanically transformed relaxor thick films with 4 & mu;m thickness exhibit an exceptional EDBS of 540 MV m-1 and reduced hysteresis with large unsaturated polarization (103.6 & mu;C 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. Nanograin engineering of normal ferroelectrics beyond compositional modification, to simultaneously enhance the dielectric breakdown strength and polarization with slim hysteresis which is typical behavior of relaxor ferroelectrics (RFE), a facile approach, is designed and revealed for high-energy-storage devices. The mechanically transformed RFE thick film (& AP;4 & mu;m) delivers a record-high energy density of 124 J cm-3.image

키워드