Abstract: To provide a carbon electrode material that is capable of decreasing cell resistance during initial charging and discharging to improve battery energy efficiency. A carbon electrode material for a negative electrode of a manganese/titanium-based redox flow battery including carbon fibers (A), carbon particles (B) other than graphite particles, and a carbon material (C) for binding the carbon fibers (A) and the carbon particles (B) other than graphite particles and satisfying (1) a particle diameter of the carbon particles (B), (2) Lc(B), (3) Lc(C)/Lc(A), (4) A mesopore specific surface area, and (5) a number of oxygen atoms bound to the surface of the carbon electrode material.

Abstract: To provide a carbon electrode material which is capable of decreasing cell resistance during initial charging and discharging while improving oxidation resistance to Mn ions. A carbon electrode material for a redox flow battery, including carbon fibers (A), graphite particles (B), and a carbon material (C) for binding the carbon fibers (A) and the graphite particles (B), the carbon electrode material satisfying (1) Lc(C), (2) Lc(C)/Lc(A), (3) an average curvature of the carbon fibers (A), and (4) a number of oxygen atoms bound to a surface of the carbon electrode material.

Abstract: A carbon electrode material is disclosed for a redox flow battery that particularly, even when using an Mn—Ti type electrolyte, while stabilizing Mn ions and suppressing a rise in cell resistance during initial charge and discharge, has excellent oxidation resistance. The electrode material includes a carbonaceous fiber, and a carbonaceous material for binding the carbonaceous fiber, and satisfies the requirements: (1) when the size of a crystallite in a c axis direction found by X-ray diffraction in the carbonaceous material (B) is Lc(B), Lc(B) is 10 nm or greater; (2) when the size of the crystallite in the c axis direction found by X-ray diffraction in the carbonaceous fiber (A) is Lc(A), Lc(B)/Lc(A) is 1.0 or greater; and (3) the number of bonded oxygen atoms of the carbon electrode material surface is 1.0% or greater than the total number of carbon atoms of the carbon electrode material surface.

Abstract: A carbon electrode material is disclosed for a redox flow battery that particularly, even when using an Mn—Ti type electrolyte, while stabilizing Mn ions and suppressing a rise in cell resistance during initial charge and discharge, has excellent oxidation resistance. The electrode material includes a carbonaceous fiber, and a carbonaceous material for binding the carbonaceous fiber, and satisfies the requirements: (1) when the size of a crystallite in a c axis direction found by X-ray diffraction in the carbonaceous material (B) is Lc(B), Lc(B) is 10 nm or greater; (2) when the size of the crystallite in the c axis direction found by X-ray diffraction in the carbonaceous fiber (A) is Lc(A), Lc(B)/Lc(A) is 1.0 or greater; and (3) the number of bonded oxygen atoms of the carbon electrode material surface is 1.0% or greater than the total number of carbon atoms of the carbon electrode material surface.

Abstract: Disclosed is a proton exchange membrane for use in fuel cells, which not only has improved proton conductivity and resistance to swelling caused by hot water but also has greater durability when used in a fuel cell, as well as a sulfonic acid group-containing segmented block copolymer constituting the proton exchange membrane, a membrane electrode assembly using the proton exchange membrane, and a fuel cell using the membrane electrode assembly. A sulfonic acid group-containing segmented block copolymer, which is a di- or multi-block copolymer including, within a molecule, at least one kind of hydrophilic segment and at least one kind of hydrophobic segment, a 0.5 g/dL solution thereof dissolved in N-methyl-2-pyrrolidone as a solvent showing a logarithmic viscosity measured at 30° C. in the range of 0.5 to 5.