Graphene Oxide-Based Aluminum Complex Ion Supercapacitor

A kind of graphene oxide-based carbon electrode material for aluminum complex ion supercapacitor (Al-SC) is developed through KNO3-assisted explosion and followed capillary densification process, which has a large specific surface area and active sites for storing positive and negative ions. With the dual-salt electrolyte composed of aluminum chloride and ionic liquid, the capacitance of Al-SC reaches 549 F g–1 in the case of current density of 0.5 A g–1 and voltage from 0 to 3.5 V. Characterizations and control experiments demonstrate that the special porous structure and abundant oxygen-containing groups endow the Al-SC with a significant high energy density of 233 W h kg–1 and ultrahigh power density of 17,500 W kg–1. The electrochemical storage mechanism of aluminum complex ions is also researched by ex situ characterization and theoretical calculation. This Al-SC paves the way for electrochemical energy storage based on aluminum species.