Ultrahigh capacitive energy storage through dendritic nanopolar design.

Electrostatic dielectric capacitors with ultrahigh power densities are sought after for advanced electronic and electrical systems owing to their ultrafast charge-discharge capability. However, low energy density resulting from low breakdown strength and suppressed polarization still remains a daunting challenge for practical applications. We propose a microstructural strategy with dendritic nanopolar (DNP) regions self-assembled into an insulator, which simultaneously enhances breakdown strength and high-field polarizability and minimizes energy loss and thus markedly improves energy storage performance and stability. For illustration, in this study, we achieved a high energy density of 215.8 joules per cubic centimeter with an efficiency of 80.7% at a high electric field of 7.4 megavolts per centimeter in a DNP structure–designed PbZr0.53Ti0.47O3-MgO film. The proposed strategy is generally applicable for development of high-performance dielectric microcapacitors. Editor's summary: Energy storage materials such as capacitors are made from materials with attractive dielectric properties, mainly the ability to store, charge, and discharge electricity. Liu et al. developed a nanocomposite of lead zirconium titanate and magnesium oxide in which the morphology of the two phases helps to increase the electrical breakdown strength of the material. The magnesium oxide–insulating phase has a dendritic morphology that inhibits the growth of the electrical trees responsible for material failure under high electric fields. The resulting composite has a high energy density, and this fabrication strategy may be useful for developing better capacitors. —Marc S. Lavine [ABSTRACT FROM AUTHOR]