Optimization of energy storage performance in 0.8Na0.5Bi0.5TiO3-0.2Bi3.25La0.75Ti3O12 thin films via defect dipoles

Dielectric capacitors put forward higher requirements on the energy storage density , working stability and fatigue resistance of materials with the increasing shortage of energy. Herein, 0.8Na 0.5 Bi 0.5 TiO 3 -0.2Bi 3.25 La 0.75 Ti 3 O 12 -x%Mn (x = 0,2,4,6) thin film capacitors are designed to address above concern. The Mn ions inhibit the valence change of Ti ions and combine with oxygen vacancies to form defect dipoles, which improve breakdown strength and energy density of the films. As a result, high energy storage density of 92.7 J cm −3 and excellent efficiency of 70.2% are synchronously achieved for the 4% Mn-doped NBT-BLT film. Besides, outstanding stability of energy storage performance also exhibit over a wide range of temperature (25–200 °C) and cycle number (10 5 ). This result provides a novel strategy for the preparation of dielectric materials with high energy storage performance and high operational stability.