title: Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials.
abstract: Electric double-layer capacitors (EDLCs) or supercapacitors (SCs) are fast energy storage devices with high pulse efficiency and superior cyclability, which makes them useful in various applications including electronics, vehicles and grids. Aqueous SCs are considered to be more environmentally friendly than those based on organic electrolytes. Because of the corrosive nature of the aqueous environment, however, expensive electrochemically stable materials are needed for the current collectors and electrodes in aqueous SCs. This results in high costs for a given energy-storage capacity. To address this, we developed a novel low-cost aqueous SC using graphite foil as the current collector and a mix of graphene, nanographite, simple water-purification carbons and nanocellulose as electrodes. The electrodes were coated directly onto the graphite foil by using casting frames and the SCs were assembled in a pouch cell design. With this approach, we achieved a material cost reduction of greater than 90% while maintaining approximately one-half of the specific capacitance of a commercial unit, thus demonstrating that the proposed SC can be an environmentally friendly, low-cost alternative to conventional SCs.
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.|STT Emtec AB, Sundsvall, SE-852 29, Sweden.
authors.forename: Nicklas
authors.initials: N
authors.lastname: Blomquist
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wells
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.
authors.forename: Britta
authors.initials: B
authors.lastname: Andres
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.
authors.forename: Joakim
authors.initials: J
authors.lastname: Bäckström
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Forsberg
authors.affiliation: Mid Sweden University, Department of Natural Sciences, Sundsvall, SE-851 70, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Olin