Abstract:

Pb(Zr_0.52Ti_0.48)O₃ (PZT) is well known normal ferroelectric material and has been intensively studied over century. For energy storage application, normal ferroelectric has several drawbacks such as low breakdown field and poor charging/discharging efficiency due to large hysteresis. Low breakdown field of crystalline PZT can be mitigated by introducing the amorphous phase to form a composite. High efficiency can be realized by making large hysteresis into slim shape. Here, a novel nanograin engineering approach based upon high kinetic energy deposition is reported, for mechanically inducing the relaxor ferroelectric behavior in a composite of crystalline and amorphous PZT, which results in simultaneous enhancement in the dielectric breakdown strength and high efficiency. Aerosol deposited thick films with 4 μm thickness exhibit an exceptional breakdown field of 540 MV/m and reduced hysteresis with energy-storage density of 124.1 J/cm³ and a power density of 64.5 MW/cm³. This approach is correlated with the generalized nanostructure design that comprises nanocrystalline phases embedded within the amorphous matrix.

Bio:

Prof. Dae-Yong JEONG, serving as the Dean of Graduate of Engineering and a professor in the Department of Materials Science and Engineering at Inha University, Korea. Graduating from Seoul National University with both undergraduate and master degrees. He received Ph.D. degree in Materials at Pennsylvania State University in 2004. Following this, he worked as a research scientist at TRS Ind. (USA) and RIEC at Tohoku University (Japan). After returning to Korea, he contributed as a senior researcher at KIST and as an assistant professor at Myongji University before joining Inha University as a professor in Sep. 2011. His current research interests include energy harvesting, ferroelectrics, nano-engineering for materials development, high energy density capacitor, and piezoelectric devices. Additionally, he has an interest in innovative Engineering Education and Intellectual properties.