Three-Dimensional\nHierarchically Porous All-Carbon\nFoams for Supercapacitor

Abstract

Three-dimensional hierarchically\nporous carbon-CNT-graphene ternary\nall-carbon foams (3D-HPCFs) with 3D macro- and mesoporous structures,\na high specific surface area (1286 m² g^–1), large bimodal mesopores (5.1 and 2.7 nm), and excellent conductivity\nhave been fabricated through multicomponent surface self-assembly\nof graphene oxide (GO)-dispersed pristine CNTs (GOCs) supported on\na commercial sponge. The commercial sponge with a 3D interconnected\nmacroporous framework not only is used as a support for GOCs and subsequently\nmulticomponent self-assembly but also serves as a 3D scaffold to buffer\nelectrolytes to reduce ion transport resistance and ion diffusion\ndistance, while the GO acts as “surfactant” to directly\ndisperse pristine CNTs, preserving the excellent electronic structure\nof pristine CNTs, and the CNTs also prevent the aggregation of graphene\nas well as improve the whole conductivity. Benefiting from the aforementioned\ncharacteristics, the 3D-HPCFs-based supercapacitors show outstanding\nspecific capacitance, high rate capability, and excellent cycling\nstability, making them potentially promising for high-performance\nenergy storage devices.