Boosting energy storage enhancement in ZrO2-coated BaTiO3 ceramics via a sol-gel method

The prime advantage of BaTiO 3 for energy-storage applications is its compatibility with reducing-atmosphere sintering processes, a well-developed technology that allows cost-effective co-firing with Ni electrodes. Nevertheless, the high hysteresis and low breakdown strength of BaTiO 3 limit its broader applications in energy-storage devices. In this work, core-shell structured BaTiO 3 @ZrO 2 ceramics are synthesized by a sol-gel method, with particular attention paid to the effects of coating time on the microstructure and energy storage properties. The introduction of ZrO 2 layer significantly increases the breakdown strength of BaTiO 3 ceramics. When the coating duration is 5 h, a high discharge energy density of 2.09 J/cm 3 is obtained, representing a fourfold enhancement over pure BaTiO 3 ceramics. Additionally, the BaTiO 3 @ZrO 2 ceramics exhibit an excellent energy storage stability against DC-bias, temperature, and frequency. This work provides a feasible way to optimize the energy storage properties of ferroelectric ceramics.