Manganese and Magnesium Co-doped Barium Titanate: A Route Towards Enhanced Energy Storage Performance via Defect Dipoles Engineering

Developing novel ferroelectrics using lead-free ceramics for cutting-edge electrical and energy storage devices is vital given the global atmospheric pollution and the energy crisis due to such ceramics' high power density and good stability. Unfortunately, the majority have weak breakdown energies and a slight variation between maximum and remaining polarization, which leads to low energy density and efficiency. Complex defect dipoles between oxygen vacancies and acceptor co-doped ions have been used to overcome this issue. By doing this, BaTiO3-based ceramics can more efficiently and densely store energy. Mg and Mn acceptor co-doping ions on the Ti site create (Mg-Ti '' - V-O(center dot center dot) and Mg-Ti '' - V-O(center dot center dot)) defect dipoles in the BaTiO3 host matrix. This increases breakdown strength to 175 kV/cm, providing a high difference between saturation and remaining polarization. This increased energy storage density (from 0.596 to 1.784 J/cm(3)) and efficiency (42-92%). Furthermore, the energy storage density is stable throughout operating frequencies and temperatures. The results indicate that defect dipole engineering can be considered a promising technique to improve the energy storage performance of lead-free ferroelectric ceramics potentially. [GRAPHICS] .