Multi-dimensional carbon composite electrodes for flexible supercapacitors

Abstract

A high-performance carbon electrode for electric double layer capacitors was designed to guarantee flexibility as well as high capacity higher than 200 F g-1. The composite of 3 dimensional (3D) carbon with 2D and 1D carbons are presented ad electrodes for flexible supercapacitors based on electric double layer formation. 3D-graphene network (3D-Gn) was used as the main active material due to its high surface area (~1500 m2 g-1). The poor electric contacts between 3D-Gn particles was complemented by highly conductive 2D graphene nano-platelet (2D-Gn). 1D carbon nanotube (1D-CNT) was mixed with 3D-Gn and 2D-Gn to provide conductive highways and fiber-reinforced network for flexibility to the multidimensional composite electrodes. The 2D-Gn effectively increased capacitance from 120 F/g for 3D-Gn/1D-CNT to 235 F/g for 3D-Gn/2D-Gn/1D-CNT in an organic liquid electrolyte. Flexibility was completely guaranteed by the 1D-CNT network by the help of organogel electrolyte. No significant change in capacitance was observed in both dynamic and static bending conditions.