| abstract |
This carbon positive electrode material for a manganese/titanium-based redox flow battery comprises 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) the particle diameter of the graphite particles (B) is at least 1 µm; (2) if the size of crystallites of the graphite particles (B) in the c-axis direction, determined by X-ray diffraction, is Lc(B), Lc(B) is at least 35 nm; (3) 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; (4) 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; (5) the number of bound oxygen atoms on the surface of the carbon positive electrode material is less than 1.0% of the total number of carbon atoms on the surface of the carbon positive electrode material; and (6) the BET specific surface area, determined on the basis of nitrogen adsorption quantity, is 0.5–1.5 m2/g. |