Synergistic Effect of CuGeO_3/Graphene Composites for Efficient Oxygen-Electrode Electrocatalysts in Li-O_2 Batteries

摘要

Hybridized 1D/2D CuGeO3/graphene composites are applied as the oxygen-electrode electrocatalysts for Li-O-2 batteries. The CuGeO3/graphene composites are synthesized by the crystallographic alignment of CuGeO3 nanowires on graphene, rendering strong heteroepitaxial coupling between the 1D oxide nanostructures and the 2D electrically conducting graphene. The inherited excellent electrocatalytic activity of the CuGeO3/graphene composites leads to lower overpotentials and more stable cycling performance of Li-O-2 cells than CuGeO3 nanowires and graphene. The relationships between CuGeO3 nanowires and graphene are studied for the oxygen reduction and oxygen evolution activity in both aqueous and nonaqueous solutions, and the electrocatalytic activity is improved by manipulating the redox pair and sp3/sp2 via surface chemical modification.