Enhancing the Energy Density of Tricritical Ferroelectrics for Energy Storage Applications

Recently, tricritical ferroelectrics have been drawn tremendous attention, owing to their ultrahigh dielectric permittivities of up to ε(r) > 5 × 10(4), and their consideration for prototype materials in the development of high-performance energy storage devices. Nevertheless, such a materials system suffers from the disadvantage of low breakdown strength, which makes its energy density far from the satisfactory level for practical application. In this paper, a material-modification approach has been reported, for improving the dielectric strength for tricritical ferroelectric materials Ba(Ti(1−x)Sn(x))O(3) (BTS) through doping with Bi(1.5)ZnNb(1.5)O(7) (BZN) additives. The results suggest that the electric strength has been largely improved in the modified tricritical ferroelectric material (BTS(x)-yBZN), and the associated energy density reaches U(e) = 1.15 J/cm(3). Further microstructure investigation indicates that the modified tricritical ferroelectric material exhibits homogenous fine grains with perovskite structure in crystal symmetry, and the BZN may help to form a special structure that could enhance the breakdown strength. The findings may advance the material design and development of high-energy storage materials.