Enhanced Energy Storage Performance of AgNbO3:xCeO2 by Synergistic Strategies of Tolerance Factor and Density Regulations

Abstract

AgNbO3-based ceramics have been widely studied as ideal lead-free materials. Herein, AgNbO3:xCeO2 (x = 0, 1, 2 mol%) ceramics were successfully prepared by the conventional solid-state reaction method. The optimization of energy storage properties is ascribed to the enhanced antiferroelectric (AFE) stability and the increased breakdown strength (Eb). The reduction of the tolerance factor leads to the enhancement of AFE stability. In addition, the enhancement of Eb is due to the increase of actual density, which is achieved through the regulation of CeO2 amount and grinding procedure in the experimental process. A high recoverable energy density (Wrec) of 5.04 J/cm3 and an energy efficiency (η) of 46.2% were achieved in AgNbO3:0.01CeO2 ceramics under an applied electric field up to 390 kV/cm. A higher η of 55.4% was obtained in AgNbO3:0.02CeO2 components. This research provides guidance for finding ceramic materials with comprehensive energy storage properties.

Enhanced Energy Storage Performance and Efficiency in Bi0.5(Na0.8K0.2)0.5TiO3-Bi0.2Sr0.7TiO3 Relaxor Ferroelectric Ceramics via Domain Engineering

“…LDEs (Al 2 O 3 and SrTiO 3 ) typically show low relative dielectric permittivity and loss factor, high E BD , and free hysteresis loop with low polarization, resulting in poor W rec and high η [11][12][13]. The AFEs (PbZrO 3 , PbHfO 3 , AgNbO 3 , and NaNbO 3 ) display elevated polarization and substantial hysteresis because of phase transition between AFE and FE phases induced by the external field, leading to extremely high W rec and low η [14][15][16][17][18]. The RFEs (Bi 0.5 Na 0.5 TiO 3 (BNT), BaTiO 3 (BT), and BiFeO 3 (BFO)) display moderate P max and small P r (Figure 1b), arising from widespread PNRs, which generally exhibit highly dynamic short-range FE orders.…”