High temperature dielectric relaxation and energy storage properties achieved in the CaZrO3–SrTiO3 composite ceramics

We synthesized lead-free ([Formula: see text]CaZrO3–[Formula: see text]SrTiO3 solid-solution ceramics and studied their structure, dielectric and energy storage properties. X-ray diffraction and scanning electron microscope reveal the microstructure of the samples. A high temperature dielectric relaxation behavior at the temperature ranges of 200[Formula: see text]C–550[Formula: see text]C is found for [Formula: see text], 0.5 and 0.7 samples. We explore that the origin of high temperature dielectric relaxation behavior is related to the migration of oxygen vacancies by Arrhenius law and oxygen treatment experiment. Moreover, with the increase of SrTiO3 content, the 0.3CaZrO3–0.7SrTiO3 exhibits high dielectric constant ([Formula: see text] at 1 kHz), low dielectric loss ([Formula: see text] at 1 kHz), good energy density ([Formula: see text] J/cm[Formula: see text] and high efficiency ([Formula: see text]%) simultaneously, and the possible causes of energy storage behavior dependence are analyzed in detail.