Abstract: A battery cell for use in a redox flow battery, the battery cell including an electrode, a membrane facing one of both surfaces of the electrode, and a bipolar plate facing the other surface of the electrode, wherein the bipolar plate includes, in a surface thereof facing the electrode, a flow channel for an electrolyte, the electrode is a porous body containing carbon materials, and a compressive strain in a thickness direction of the electrode when a compressive stress of 0.8 MPa is applied in the thickness direction of the electrode is 20% or more and 60% or less.

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: A battery cell for use in a redox flow battery, the battery cell including an electrode, a membrane facing one of both surfaces of the electrode, and a bipolar plate facing the other surface of the electrode, wherein the bipolar plate includes, in a surface thereof facing the electrode, a flow channel for an electrolyte, the electrode is a porous body containing carbon materials, and a compressive strain in a thickness direction of the electrode when a compressive stress of 0.8 MPa is applied in the thickness direction of the electrode is 20% or more and 60% or less.

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 redox flow battery includes a battery cell to which a positive electrolyte and a negative electrolyte are supplied, and an electrical quantity measurement system configured to measure a quantity of electricity when a predetermined amount of electrolyte is discharged, for at least one of the positive electrolyte and the negative electrolyte.

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 redox flow battery includes a battery cell to which a positive electrolyte and a negative electrolyte are supplied, and an electrical quantity measurement system configured to measure a quantity of electricity when a predetermined amount of electrolyte is discharged, for at least one of the positive electrolyte and the negative electrolyte.