Abstract: Discussed herein is a porous carbon microtube (PCM)-based composite film electrode. The PCMs are fabricated using an activation process to form the porous surface of the microtubes that is made up of mesopores and micropores. The electrode is formed from a mixture of a 2-dimensional material such as graphene oxide (GO) and a plurality of PCM that self-assemble in response to mixing. The mixture is disposed on a membrane in a vacuum filtration apparatus to form a precursor film which is reduced to form the composite film electrode.

Abstract: A method of producing a carbon core-graphene shell material is disclosed. The method can include obtaining a dispersion comprising a grafted graphene oxide material and a polymerizable carbon material dispersed in a liquid medium, polymerizing the polymerizable carbon material in the dispersion to obtain a grafted graphene oxide coated polymerized carbon material dispersed in the liquid medium, evaporating the liquid medium from the dispersion, and heating the grafted graphene oxide coated polymerized carbon material to obtain the carbon core-graphene shell material.

Abstract: Methods for producing a carbon material-graphene composite are described. A method can include obtaining a dispersion comprising a graphene oxide material and a carbon material dispersed in a liquid medium, evaporating the liquid medium to form a carbon material-graphene composite precursor, and annealing the composite precursor at a temperature of 800° C. to 1200° C. in the presence of an inert gas to form the carbon material-graphene composite. The graphene oxide material can be grafted graphene oxide. Flexible carbon material-graphene composites are also described. The composites can have a polyacrylonitrile (PAN)-based activated carbon attached to a graphene layer, have a surface area of 1500 m2/g to 2250 m2/g, and a bimodal porous structure of micropores and mesopores.