Substantially improved energy storage capability of ferroelectric thin films for application in high-temperature capacitors

Abstract

Ferroelectric thin films capacitors have been potentially applied in advanced electronics and electric power systems because of their high power densities and fast charge–discharge responses. However, continuous operation of the ferroelectric thin film capacitors under elevated temperatures and high electric fields still remains a huge challenge. Herein, we report eco-friendly BiFeO₃-modified Bi_3.15Nd_0.85Ti_2.8Zr_0.2O₁₂ (BNTZ) free-lead ferroelectric thin films for high-temperature capacitor applications that simultaneously possess high-energy storage density (W_reco), efficiency (η), and temperature-dependent stability. The BNTZ–0.09BFO thin film shows a first-class-level W_reco (∼124 J cm⁻³) along with high η (∼81.9%), which surpasses almost all the Pb-contained and Pb-free perovskite ferroelectrics. Of particular importance is that excellent fatigue endurance for long-term stability (10⁹ cycles) and thermal stability (−100 °C to 200 °C) could be achieved. This work represents a new design paradigm to exploit advanced dielectric capacitor materials for high-temperature electronics and energy storage devices.