M. Benyoussef, M. Zannen, J. Belhadi, B. Manoun, J.L. Dellis, M. El Marssi, A. Lahmar
Laboratory of physics of condensed matter - University of Picardie Jules Vernes,
Keywords: NBT-based ceramics, dielectric properties, ferroelectric properties, energy storage
Summary:Energy storage is one of the vital technologies for judicious utilization of energy, aiming to meet the challenge of fossil fuel depletion. Furthermore, due to the concern about climate change and atmospheric pollution, great interest has been devoted to energy storage devices based on lead-free materials that present high storage capacity. One of the new areas of interest is a high energy density at high operating temperatures (>300°C) for use in applications in which materials are subjected to harsh operating conditions, such as in power electronics, deep-well oil and gas exploration, and hybrid vehicles applications. Sodium bismuth titanate (Abbreviated as NBT) is considered as one of the promising candidates for energy storage applications due to its interesting properties. However, pure NBT suffers from high conductivity and large coercive field. Doping with rare earth elements was found as an appropriate way to enhance the physical properties of NBT. In the present work, we examine the influence of Dysprosium element addition on the structural, electrical, and energy storage properties of Na0.5(Bi(1-x)Dyx)0.5TiO3 (xDyNBT) system. Interestingly, the inclusion of Dy3+ allows not only a substantial decrease of the coercive field and increase of the resistivity of pure NBT but also leads to a high stability of the dielectric permittivity (ɛ) over a wide temperature range (~90-510°C) with ∆ɛ ≤±15% variation. Further, the studied system was found to exhibit improved energy storage density of (1.2 J/cm3) at high temperatures (200°C). The obtained results are very promising and open great potential for high-temperature power electronics applications.