A review of energy storage applications of lead-free BaTiO3-based dielectric ceramic capacitors

Renewable energy can effectively cope with resource depletion and reduce environmental pollution, but its intermittent nature impedes large-scale development. Therefore, developing advanced technologies for energy storage and conversion is critical. Dielectric ceramic capacitors are promising energy storage technologies due to their high-power density, fast charge and discharge speed, and good endurance. Despite having high-power density, their low energy storage density limits their energy storage applications. Lead-free barium titanate (BaTiO 3 )-based ceramic dielectrics have been widely studied for their potential applications in energy storage due to their excellent properties. While progress has been made in improving their energy storage density, several challenges need to be addressed. This paper presents the progress of lead-free barium titanate-based dielectric ceramic capacitors for energy storage applications. Firstly, the paper provides an overview of existing energy storage technologies and the fundamental principles of energy storage in dielectrics. Then we reviewed the advances of lead-free barium titanate-based ceramic as a dielectric material in ceramic capacitors and discussed the progress made in improving energy storage properties via composition modification, various preparation methods, and structure modification. The energy storage density of ceramic bulk materials is still limited (less than 10 J/cm 3 ), but thin films show promising results (about 10 2 J/cm 3 ). Finally, the paper also highlights some recommendations for the future development and testing of ceramics dielectrics for energy storage applications which include investigation of performance at lower temperatures ( 200 °C), compatibility with low-cost electrodes, scale-up capability and standardizing the test parameters.