Bismuth ferrite-based lead-free ceramics and multilayers with high recoverable energy density

Lead-free ceramics with high recoverable energy density (W-rec) and energy storage efficiency () are attractive for advanced pulsed power capacitors to enable greater miniaturization and integration. In this work, dense bismuth ferrite (BF)-based, lead-free 0.75(Bi1-xNdx)FeO3-0.25BaTiO(3) (BNxF-BT) ceramics and multilayers were fabricated. A transition from a mixed pseudocubic and R3c to a purely pseudocubic structure was observed as x increased with the optimum properties obtained for mixed compositions. The highest energy densities, W approximate to 4.1 J cm(-3) and W-rec approximate to 1.82 J cm(-3), were achieved for BN15F-BT, due to the enhanced breakdown field strength (BDS approximate to 180 kV cm(-1)) and large maximum polarization (P-max approximate to 40 C cm(-2)). The multilayers of this composition possessed both a high W-rec of 6.74 J cm(-3) and of 77% and were stable up to 125 degrees C. Nd doped BF-based ceramics with enhanced BDS and large W-rec are therefore considered promising candidates for lead-free energy storage applications.