Recent development of lead-free relaxor ferroelectric and antiferroelectric thin films as energy storage dielectric capacitors

Dielectric electrostatic capacitors are breakthroughs in energy storage applications such as pulsed power applications (PPAs) and miniaturized energy-autonomous systems (MEASs). Low power density, poor charge-discharge speed, and deprived breakdown strength of batteries and electrochemical capacitors limit their use in various implantable, wearable, and portable electronics. Recently, relaxor ferroelectric (RFE) and anti-ferroelectric (AFE) thin film capacitors have emerged as appropriate candidates for PPAs and MEASs. High energy storage density (50-120 J/cm3), large power density (109-1010 W/kg), ultrafast charge-discharge speed (μs range), superior dielectric breakdown strength (DBS) (~MV/cm), and excellent thermal stability (150-275 oC) in RFE and AFE capacitors are appropriate for high power and miniaturized electronic device applications. In this review article, we portray a succinct discussion of the energy storage properties of RFE and AFE-based thin films.