Converging pathways to high energy density: A review of emerging strategies in ceramic capacitors optimization

Recently the need for cost effective, ecofriendly, energy storage device that can store electrical energy has been peaked. Among the commercially available systems the dielectric capacitors have a significant position owing to its high-power density. These capacitors are usually employed in a variety of applications ranging from modern consumer electronics to various pulsed power applications due to its high charging and discharging speeds. Dielectric materials serve as fundamental elements in dielectric capacitors, directly influencing their operational efficacy. This review provides a concise examination of the energy storage mechanisms and fundamental properties of dielectric capacitors, while also encapsulating the energy storage performances of diverse lead-free ceramic systems that are classified within both linear and nonlinear dielectric categories. Furthermore, the article emphasizes the opportunities and challenges associated with enhancing energy storage density, polarization behavior, and overall efficiency, and also highlight the modern strategies to overcome these limitations, including defect engineering, nanodomain and superparaelectric engineering, high-entropy design, local random field regulation, and microstructural tailoring through controlled sintering. By exploring these advancements, this review aims to provide insights into the development of high-performance dielectric capacitors for sustainable energy storage solutions.