PNNL

Abstract

Surfactant or polymer directed self-assembly has been widely investigated to prepare nanostructured metal oxides, semiconductors and polymers, but this approach is mostly limited to two-phase materials, organic/inorganic hybrids, and nanoparticle or polymer-based nanocomposites. Self-assembled nanostructures from more complex, multiscale and multiphase building blocks have been explored with limited success. Here, we demonstrate a ternary self-assembly approach using graphene as fundamental building blocks to construct metal oxide-graphene nanocomposites. A new class of layered nanocomposites is formed containing stable, ordered alternating layers of nanocrystalline metal oxides with graphene/graphene stacks. Alternatively, the graphene material can be incorporated into liquid-crystal-templated nanoporous structures to form high surface area, conductive networks. The self-assembly method can be also used to fabricate free standing, flexible metal oxide-graphene nanocomposite films and electrodes. We investigate the Li-ion insertion properties of the self-assembled electrodes for energy storage and show that the SnO2-graphene nanocomposite films can achieve near theoretical specific energy density without a significant charge/discharge degradation.