The Interplay of Oxygen Functional Groups and Folded Texture in Folded-Graphene Cathode

As discussed in last chapter, we have originally reported a novel approach toward ultrafast high-volumetric sodium storage of folded-graphene electrodes through surface-induced redox reactions, which successfully preserved the capacitive reactivity in an intensively densified texture and dramatically improve the volumetric efficiency of energy storage, indicating a prospective avenue toward compact electrochemical energy storage. Simply by assembling graphene oxide nanosheets into a hydrogel and controlling the evaporation process, densified graphene electrodes were prepared and excellent long-term stability and rate capability were also witnessed, which were quite competitive among related reports. Whereas, if we want to strive for further advancement, a critical question has to be thoroughly understood, namely what is the interplay of oxygen functional groups and folded texture in densified graphene electrodes.