A three-dimensional (3D) fine network structure of thin carbon microflakes inside a loosely entangled carbon-fiber matrix was formed by applying an ice-template method to a graphite oxide (GO) dispersion in the matrix and thermal reduction of the GO. Vanadium-ion redox reactions were investigated in the network of reduced GO (RGO) for potential application as electrodes in vanadium redox flow batteries (VRFB). The development of the fineness, the degree of graphitization, the structural disorder, and the surface composition were characterized. The interaction between the carbon surface species and the vanadium ions was implied by the X-ray absorption fine structure (XAFS). The structure of the 3D RGO network was clearly correlated to the activity for the VRFB positive electrode reactions, and the development of the fine network structure effectively enhanced the reactions due to increased exposure of the edge planes and sufficient dispersion of the active sites. Ice and easy: A three-dimensional network structure of reduced graphite oxide inside a carbon-fiber matrix was formed by applying an ice-template method. The development of the fine structure was attained to effectively enhance vanadium-ion redox reactions (see figure).
- Graphite oxide
- Redox chemistry
- Structure-activity relationships
- X-ray absorption