| abstract |
Provided is a carbon electrode material for a redox flow battery that can decrease cell resistance during initial charging by stabilizing magnesium ions even if a manganese–titanium electrolyte is used, and that has outstanding oxidation resistance. This electrode material is made from carbon fibers (A), graphite particles (B), and a carbon material (C) for binding the carbon fibers (A) and the graphite particles (B), and satisfies the following conditions: (1) if the size of crystallites of the carbon material (C) in the c-axis direction, determined by X-ray diffraction, is Lc(C), Lc(C) is at least 10 nm; (2) if the size of crystallites of the carbon fibers (A) in the c-axis direction, determined by X-ray diffraction, is Lc(A), Lc(C)/Lc(A) is at least 1.0; (3) in the structure of the carbon fibers (A), the average rate of curvature is at least 1 R and the average fiber diameter is 5–15 µm; and (4) the number of bound oxygen atoms on the surface of the carbon electrode material is at least 1.0% of the total number of carbon atoms on the surface of the carbon electrode material. |