Phenolic carbon cloth-based electric double-layer capacitors with conductive interlayers and graphene coating

Phenolic resin-derived activated carbon (AC) cloths are used as electrodes for large scale electric double-layer capacitors (EDLCs) or supercapacitors. To increase the energy and power density of the supercapacitor, the contact resistance between the carbon cloth and the aluminum foil current collector is reduced by modifying the Al current collectors. Different modified Al current collectors, including Toyal-Carbo(surface modified Al), DAG (deflocculated Acheson graphite) coating, and poly(3,4-ethylenedioxythiophene) (PEDOT)-carbon black coating have been tested and compared. Another solution investigated in this study is to coat AC cloth with graphene using electrophoretic deposition (EPD). The use of modified Al current collectors and graphene composite coated AC cloth are shown to greatly reduce the contact resistance between the AC cloth and the Al foil. Increased capacitance is also demonstrated attributed to added pseudocapacitance from the PEDOT interlayer and the increased specific surface area in the grapheme-coated AC cloth.