Redox Molecule Adsorbed Graphene Films with Compact Structure for Electrochemical Energy Storage

Graphene films with compact structure and high ion accessible surface are essential to achieve dense energy storage with high-performance. Thus we prepared hydroquinone (HQ) adsorbed reduced graphene oxide (HQ-rGO) films with high packing density by capillary pressure. Hence, sulphuric acid was pre-intercalated between graphene sheets to reduce ion transport resistance, and adsorbed HQ molecules provide abundant pseudocapacitance. Finally, the two materials play a synergistic effect, significantly improving the capacitance performance. The resulting HQ-rGO films exhibit high volumetric capacitance of ~189.4F cm−3 at 1mA cm−2, and after current density increase to 30mA cm−2, its capacitance retention can achieve 54% of original value, which demonstrates excellent rate performance of the device. Clearly, this strategy is great promising for fabrication of electrode material with high performance.