The coplanar graphene oxide/graphite heterostructure-based electrodes for electrochemical supercapacitors

Abstract

Graphene-based foams were widely applied as electrode (or substrate) in energy storage devices. However, many efforts were spent on exfoliation, purification and fabrication process as the graphene-based materials were mostly fabricated by the assembly of GO nanosheets. In this work, a novel top-down strategy was presented to directly fabricate the GO/graphite foam from graphite paper. Under a controllable intercalation/expansion method, the graphite layers were partly expanded (and oxidized) and cross-linked by the coplanar GO/graphite heterostructure. The expanded GO parts endowed the electrode high surface area and pseudocapacitance, while the coplanar unexpanded graphite parts supported the electrode with hierarchical nanostructure and superior conductive network. The synergistic effect with GO and graphite greatly enhanced the electrochemical performance of the heterostructure electrodes. This method suggests an alternative to revisit the electrode production made from graphite and GO, which could greatly simplify the production flow of graphene-based electrodes.