Three-Dimensional Hierarchically Porous All-Carbon Foams for Supercapacitor

Abstract

Three-dimensional hierarchically porous carbon-CNT-graphene ternary all-carbon foams (3D-HPCFs) with 3D macro- and mesoporous structures, a high specific surface area (1286 m(2) g(-1)), large bimodal mesopores (5.1 and 2.7 nm), and excellent conductivity have been fabricated through multicomponent surface self-assembly of graphene oxide (GO)-dispersed pristine CNTs (GOCs) supported on a commercial sponge. The commercial sponge with a 3D interconnected macroporous framework not only is used as a support for GOCs and subsequently multicomponent self-assembly but also serves as a 3D scaffold to buffer electrolytes to reduce ion transport resistance and ion diffusion distance, while the GO acts as "surfactant" to directly disperse pristine CNTs, preserving the excellent electronic structure of pristine CNTs, and the CNTs also prevent the aggregation of graphene as well as improve the whole conductivity. Benefiting from the aforementioned characteristics, the 3D-HPCFs-based supercapacitors show outstanding specific capacitance, high rate capability, and excellent cycling stability, making them potentially promising for high-performance energy storage devices.