(70g) Surface and Structure Engineered Graphenes for Liquid-Phase Processing Toward High-Performance Porous Solid Electrode Films

Hu, M. Z., Oak Ridge National Laboratory

Graphene has become a class of materials that have potential impact on diverse applications such as energy storage (supercapacitors or batteries), electronics, and membranes. Our studies consider the synthesis and processing route to produce structure controlled graphene particulate film of high-performance electrode, starting with low-cost graphite powders. This presentation will present a new chemical processing route with serial of step intermediate products: from graphite powders, graphene oxide (GO) sheet particles, surface modified GO particles, controlled self-assembly particles of GO or reduced GO (rGO) that contains the desirable sheet-stacking architecture, liquid dispersion of structure-engineered rGO particles, and to solid film deposit containing desirable pore size and architecture. Surface modification with the appropriate molecular ligands are used as key strategies to re-assembly the engineered graphene particles and controlled dispersion of graphene particles into either aqueous or non-aqueous solvents. We are reporting our recent results on overcoming the dispersion issue of graphene into non-polar solvents. We also show the significant capacitance improvement due to molecular ligand-assisted interspace control between graphene sheets inside each re-assembled or stacked particulate.  Finally, we demonstrate that the pore size and pore structure control of particulate electrode film deposits is critical to the final film performance.