Chapter 10 - Materials science of multifunctional supercapacitors based on nanocarbon networks

Abstract

Electrochemical supercapacitors comprising electrodes based on nanocarbon networks in multifunctional devices with augmented mechanical properties, and particularly electrodes of nonwoven fabrics of carbon nanotube fibers, embody interesting new materials science challenges. Consideration of the basic properties of different nanocarbon and pseudocapactive building blocks captures the potential of nanocarbons to take the roles of scaffold, current collector, and active material in supercapacitors. Materializing these properties as ensembles of nanocarbons leads to a compromise between porosity and aggregation, closely related to the fabrication method amongst vacuum filtration of dispersions and preassembly macroscopic fibers, and leading to a fundamentally different balance within the mechanical–electrochemical spectrum. Capacitance of nanocarbon-based electrodes is increased by combination with pseudocapactive materials, but such increase can be a consequence of other factors such as changes in chemical capacitance of the nanocarbon and wetting by aqueous electrolytes. Nanocarbons are also key enablers in supercapacitors with structural mechanical properties.