A polarization double-enhancement strategy to achieve super low energy consumption with ultra-high energy storage capacity in BCZT-based relaxor ferroelectrics

Due to dielectric capacitors' already-obtained fast charge-discharge speed, research has been focused on improving their W rec . Increasing the polarization and enhancing the voltage endurance are efficient ways to reach higher W rec , however simultaneous modification still seems a paradox. For example, in the ferroelectric-to-relaxor ferroelectric (FE-to-RFE) phase transition strategy, which has been widely used in the latest decade, electric breakdown strength ( E b ) and energy storage efficiency ( η ) always increase, while at the same time, the maximum polarization ( P max ) inevitably decreases. The solution to this problem can be obtained from another degree of freedom, like defect engineering. By incorporating Bi(Zn 2/3 Ta 1/3 )O 3 (BZT) into the Ba 0.15 Ca 0.85 Zr 0.1 Ti 0.9 O 3 (BCZT) lattice to form (1 − x )Ba 0.15 Ca 0.85 Zr 0.1 Ti 0.9 O 3 - x Bi(Zn 2/3 Ta 1/3 )O 3 (BCZT- x BZT) solid-solution ceramics, in this work, ultrahigh ferroelectric polarization was achieved in BCZT-0.15BZT, which is caused by the polarization double-enhancement, comprising the contribution of interfacial and dipole polarization. In addition, due to the electron compensation, a Schottky contact formed at the interface between the electrode and the ceramic, which in the meantime, enhanced its E b . A W rec of 8.03 J cm −3 , which is the highest among the BCZT-based ceramics reported so far, with an extremely low energy consumption, was finally achieved. BCZT-0.15BZT also has relatively good polarization fatigue after long-term use, good energy storage frequency stability and thermal stability, as well as excellent discharge properties. Due to the combination of interfacial polarization and depolarization, the energy density of BCZT-based lead-free ferroelectric reached 8.03 J cm −3 at only 425 kV cm −1 . High energy density with extremely low energy consumption was achieved.