Dielectric film capacitors have drawn much attention in recent years due to the fast charge–discharge rate, while the energy storage performance at ultra-high temperature needs to be satisfied for the increasing demand of the market. Here, we develop an ultrahigh-temperature capacitor of relaxor ferroelectric (RFE) films via controlling polarization behavior. The (1 1 0) oriented 0.85BaTiO3-0.15Bi(Mg0.5Zr0.5)O3 (BT-BMZ) thin film, with anisotropic strain and the optimal ratio of extrinsic/intrinsic polarization, exhibits minimized hysteresis loss and maintains maximum polarization. The (11 0) oriented film capacitor shows giant energy storage density 104.94 J/cm3, with energy storage efficiency 75.83 % BT-BMZ at room temperature. Moreover, the BT-BMZ capacitor achieves excellent thermal stability, from −100 °C to 400 °C, with an energy density 51.61 J/cm3 at an efficiency 79.36 % due to the low leakage current and hysteresis loss. This work demonstrates that the energy storage performance can be enhanced by adjusting the ratio of intrinsic/extrinsic polarization and provides a feasible method for improving high-temperature performance of capacitors.

Link:Ultrahigh-temperature capacitors realized by controlling polarization behavior in relaxor ferroelectric - ScienceDirect