Enhancing energy storage performance in barium titanate ceramics through mg-doping via creation of defect dipoles engineering

Abstract: Enhancing the efficacy of energy storage materials is crucial for advancing contemporary electronic devices and energy storage technologies. This research focuses on boosting the energy storage capabilities of BaTiO₃ ceramics through Mg²⁺ doping. Introducing Mg²⁺ ions into the BaTiO₃ lattice induces defects and grain boundary effects, significantly influencing ferroelectric properties. Rietveld refinements of X-ray diffraction confirmed that both pure and Mg-doped samples show the same tetragonal phase. SEM analysis revealed a refined grain microstructure in the Mg²⁺ doped BT sample, which resulted in improved thermal stability and pinched ferroelectric hysteresis loops. Incorporating Mg²⁺ ions into the BT host lattice significantly enhanced energy storage density from 0.204 J/cm³ to 1.42 J/cm³ and efficiency rising from 21 to 89%. This enhancement is attributed to defect dipole engineering and the attainment of fine grain size. Furthermore, an examination of the electronic structure, overall density of states (DOS), and electronic density of both samples is undertaken. The defect dipole mechanism proposed in this study introduces a novel and promising strategy for developing high-performance energy storage in ferroelectric ceramics, holding great promise for next-generation applications.