Ultra-high energy storage performance in Bi5Mg0.5Ti3.5O15 film via a low temperature-induced ergodic relaxation state

Abstract

Good low-temperature energy storage characteristics are conducive to the successful merger of Si-based semiconductor technology with dielectric energy storage films. Due to low maximum polarization intensity and poor crystallinity at low temperatures, however, it is difficult for dielectric energy storage films to attain excellent dielectric energy storage properties. Herein, Bi5Mg0.5Ti3.5O15 films accomplish the shift from a non-ergodic relaxor state to an ergodic relaxation state by lowering the annealing temperature, which simultaneously increases insulating characteristics. The energy loss is reduced while maintaining a high polarization intensity and high breakdown electric field, which results in the ultra-high energy storage density (122.2 J/cm3) and efficiency (77.3 %) of the Bi5Mg0.5Ti3.5O15 film at an annealing temperature of 500 °C. Meanwhile, the Bi5Mg0.5Ti3.5O15 films show excellent stability in terms of temperature (−20 °C to 150 °C), frequency (0.05 kHz–20 kHz), and fatigue resistance (1 ×108). The domain states and insulation properties of temperature-controlled films are used in this work to achieve ultra-high energy storage properties, and a concise and feasible scheme for the application of low temperature energy storage films in semiconductor technology is provided.