Visibly transparent supercapacitors

Abstract

Supercapacitors with novel functionalities such as transparency and flexibility are gaining attention to meet the increasing demand for intelligent and smart electronics. Transparent supercapacitors (TSCs) find application in modern appliances such as portable electronics and are especially inevitable for fully integrated transparent devices, thanks to their high-power density, fast charging and discharging ability, and longer life. Transparency is generally achieved by preparing thin films of active electrode material or by adopting lithographic methods for nanostructured electrodes that control the thickness and fill factor without significantly affecting intrinsic conductivity and capacitance. This review discusses all such approaches with a focus on the choice of electrode materials and their design and fabrication for achieving visible transparency in supercapacitors for advanced multifunctional devices. Additionally, it covers the basic concept, device structures, critical parameters, and figure of merit used specifically for transparent supercapacitors. An overview of recent experimental attempts to explore the potential applications of transparent supercapacitors is given, along with the challenges foreseen for the development.