Topic: Hybrid Supercapacitors: Mechanism, Design, Materials and Applications

The use of intermittent renewable energy presents demands for suitable energy storage systems with high power output in short time and high energy density. Hybrid supercapacitors, comprising faradaic and non-faradic electrodes, set bridges between high-power and high-energy processes in a single device. These devices feature high power density, high energy density and long lifespan, making them suitable for rapid energy output scenes, such as electric vehicles or power tools. However, differences in energy storage mechanisms induce imbalances in the stable potential interval, capacity, power density and cycling stability between the anode and cathode, resulting in unsatisfactory full cell electrochemical performances. To address these challenges and promote the application of hybrid supercapacitors, this Special Issue will report the advances in the research not only on materials development of anodes, cathodes and electrolytes but also on advanced technologies of anode-cathode matching, electrode structure design, sustainable electrode fabrication, and full cell application.