Temperature-stable MgO-doped BCZT lead-free ceramics with ultra-high energy storage efficiency

Temperature-stable dielectric capacitors with high energy storage properties are increasingly attractive in modern electronic devices. Hence, Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramics with MgO additive were synthesized via the solid-state method. The phase identification of the specimens can be investigated by the XRD analysis and show a pure phase of the perovskite structure. The SEM micrograph reveals that the smallest grain size is found in the x = 0.50 composition. The diffuse phase transition (DPT) behavior of the BCZT ceramics is enhanced by MgO additive, which demonstrates that the MgO additive plays a significant role on the DPT behavior. The highest energy storage density 275.56 mJ/cm3 and excellent energy storage efficiency 91.55% measured at room temperature are noted for the x = 0.50 composition. By further investigating the temperature stability of BCZT-0.5 wt% ceramics, the variation of the energy storage density can be maintained within ±14.18% and the energy storage efficiency has dramatically increased from 92.60% to 97.08% at the operating temperature range of 20–120 °C. It indicates that 0.50 wt% MgO doped BCZT ceramics can stably work over a wide operating temperature range with ultra-high energy storage efficiency.