Symposium EN13—Capacitive Energy Storage—Fundamentals, Materials and Devices
Supercapacitors are important energy storage devices because they fill a critical gap between batteries and electrostatic capacitors. Along with batteries, interest in capacitive energy storage has been steadily increasing. This is because supercapacitors have potential in many applications either as stand-alone storage devices, or in combination with batteries in battery-assist applications. Research on supercapacitors has recently accelerated on many fronts, which we will cover in this symposium. For example, a large number of new materials (both double layer and pseudocapacitive) are being extensively evaluated as supercapacitor anodes and cathodes. In addition, various types of devices are being studied including asymmetric supercapacitors, hybrid supercapacitors, where one of the electrodes acts as battery, microsupercapacitors for on-chip storage, fractional electrochemical supercapacitors, flow supercapacitors, self-powered supercapacitors, and electrochemical supercapacitors for frequency filtering. In all these applications, electrodes have included polymers, sulfides, phosphides, nitrides, MOFs, and a large variety of 2D materials.In addition, various electrolytes are being developed, including organic electrolytes, redox electrolytes, and solid-state electrolytes.
A key focus of this symposium will be the fundamental materials issues that face the supercapacitor community. This will include development of new classes of materials, including materials that exhibit both pseudocapacitance and intercalation capacitance, battery-like materials for hybrid supercapacitors, and better electrolytes. Strategies to improve the cycling stability of pseudocapacitive materials such as surface coatings by atomic layer deposition and nanocomposite design will be addressed. The development of anode materials other than carbon that work in negative voltage window has been a serious challenge, and research efforts in this area will be covered. Finding materials, particularly, 2D materials with large intercalation capacitance would increase capacitance beyond just surface redox reactions, and has good potential. In addition, improving the conductivity of gel electrolytes is an important topic for development of solid state electrochemical pseudocapacitors and will be covered.