Enhanced energy storage performance in Na0.5Bi0.5(Ti,Mn)O3-SrTiO3 ferroelectric thin films via aging process

Optimizing energy storage performance often involves increasing the discrepancy between maximum polarization and remanent polarization ( P max - P r ) and breakdown strength ( E b ). Here, aging treatment in acceptor doped NBT-based film is taken for increasing both E b and P max - P r by constructing ordered defect dipoles. Enhanced P max - P r value of 80.6 μC/cm 2 and high E b of 2630 kV/cm are obtained in the aged (Na 0.5 Bi 0.5 ) 0.55 Sr 0.45 Ti 0.99 Mn 0.01 O 3 thin film, which can be attributed to the reversible domain switching caused by ordered defect dipoles and low oxygen vacancies concentration. Accordingly, an energy density of 72.4 J/cm 3 with an efficiency of 76.8 % was achieved simultaneously in the aged film, which are approximately raised by 80.6 % and 45.2 %, respectively, compared with the unaged state. The stable energy storage performances are achieved within the scope of operating temperatures (20–200 ◦ C) and frequencies (0.2–10 kHz). These results provide a new route to take usages of aging process for optimizing the energy performance of NBT-based thin films.