Self-Assembled, Redox-Active Graphene Electrodes for High-Performance Energy Storage Devices

Graphene-based materials have been utilized as a promising approach in designing high-performance electrodes for energy storage devices. In line with this approach, functionalized graphene electrodes have been self-assembled from the dispersion of graphene oxide (GO) in water at a low temperature of 80 degrees C using tetrahydroxy1-1,4-benzoquinone (THQ) as both the reducing and redox-active functionalization agent. We correlated the electrochemical performance of the electrode with surface oxygen chemistry, confirming the role of THQ for the reduction and redox-active fiinctionalization process. The assembled graphene electrodes have a 3D hierarchical porous structure, which can facilitate electronic and ionic transport to support fast charge storage reactions. Utilizing the surface redox reactions introduced by THQ the functionalized graphene electrodes exhibit high gravimetric capacities of similar to 165 mA h/g in Li cells and similar to 120 mA h/g in Na cells with high redox potentials over similar to 3 V versus Li or Na, proposing promising positive electrodes for both Li and Na ion batteries.