Abstract: An electrode for a redox flow battery through which an electrolyte is circulated includes a porous body, and reactive particles that contribute to a battery reaction. The reactive particles are pressed against the porous body by a flow of the electrolyte without being immobilized on the porous body.

Abstract: A bipolar plate to be arranged opposite to an electrode that is supplied with an electrolyte solution to cause a battery reaction includes a plurality of groove portions in which the electrolyte solution flows and rib portions that each separate the adjacent groove portions on at least one of its front and back surfaces. A specific rib portion including a contact surface to be brought into contact with the electrode and one or more recessed portions that are open in the contact surface is included among the rib portions.

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 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 bipolar plate to be arranged opposite to an electrode that is supplied with an electrolyte solution to cause a battery reaction includes a plurality of groove portions in which the electrolyte solution flows and rib portions that each separate the adjacent groove portions on at least one of its front and back surfaces. A specific rib portion including a contact surface to be brought into contact with the electrode and one or more recessed portions that are open in the contact surface is included among the rib portions.

Abstract: A redox flow battery includes a battery cell including a positive electrode, a negative electrode, and a membrane disposed between these two electrodes; a positive electrode electrolyte supplied to the positive electrode; and a negative electrode electrolyte supplied to the negative electrode, wherein the positive electrode electrolyte contains manganese ions and a phosphorus-containing substance, the negative electrode electrolyte contains at least one species of metal ions selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and a concentration of the phosphorus-containing substance is 0.001 M or more and 1 M or less.

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: Provided is a redox flow battery that allows suppression of generation of precipitate and also has a high energy density. The redox flow battery includes a battery cell including a positive electrode, a negative electrode, and a membrane interposed between the electrodes, the battery being configured to be charged and discharged while a positive electrode electrolyte and a negative electrode electrolyte are supplied to the battery cell, wherein the positive electrode electrolyte contains manganese ions, titanium ions, and reactive metal ions, the negative electrode electrolyte contains at least one species of metal ions selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and the reactive metal ions are at least one selected from vanadium ions, chromium ions, iron ions, cobalt ions, copper ions, molybdenum ions, ruthenium ions, palladium ions, silver ions, tungsten ions, mercury ions, and cerium ions.

Abstract: Provided is a method of operating an RF battery in which charging and discharging are performed by circulating and supplying a positive electrode electrolyte in a positive electrode tank to a positive electrode and circulating and supplying a negative electrode electrolyte in a negative electrode tank to a negative electrode. The positive electrode electrolyte contains manganese ions and added metal ions. The negative electrode electrolyte contains at least one species of metal ions selected from the group consisting of titanium ions, vanadium ions, and chromium ions. The added metal ions are at least one selected from the group consisting of cadmium ions, tin ions, antimony ions, lead ions, and bismuth ions.

Abstract: A redox flow cell membrane includes a porous membrane that has a mean flow pore size of not more than 100 nm, that has a thickness of not more than 500 ?m, and that has an air flow rate of not less than 0.1 ml/s·cm2. When the redox flow cell membrane is used for a V—V-based redox flow cell, the porous membrane preferably has a mean flow pore size of not more than 30 nm.

Abstract: A redox flow battery includes a battery cell including a positive electrode, a negative electrode, and a membrane disposed between these two electrodes; a positive electrode electrolyte supplied to the positive electrode; and a negative electrode electrolyte supplied to the negative electrode, wherein the positive electrode electrolyte contains manganese ions and a phosphorus-containing substance, the negative electrode electrolyte contains at least one species of metal ions selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and a concentration of the phosphorus-containing substance is 0.001 M or more and 1 M or less.

Abstract: Provided is a method of operating an RF battery in which charging and discharging are performed by circulating and supplying a positive electrode electrolyte in a positive electrode tank to a positive electrode and circulating and supplying a negative electrode electrolyte in a negative electrode tank to a negative electrode. The positive electrode electrolyte contains manganese ions and added metal ions. The negative electrode electrolyte contains at least one species of metal ions selected from the group consisting of titanium ions, vanadium ions, and chromium ions. The added metal ions are at least one selected from the group consisting of cadmium ions, tin ions, antimony ions, lead ions, and bismuth ions.

Abstract: An electrolyte for a redox flow battery has a total concentration of arsenic ions and antimony ions of 15 mass ppm or less. In an example of the electrolyte for a redox flow battery, preferably, the concentration of the arsenic ions is 10 mass ppm or less. In another example of the electrolyte for a redox flow battery, preferably, the concentration of the antimony ions is 10 mass ppm or less.

Abstract: Provided is a redox flow battery that can suppress generation of a precipitation on a positive electrode. The redox flow battery performs charging and discharging by supplying a positive electrode electrolyte and a negative electrode electrolyte to a battery cell that includes a positive electrode, a negative electrode, and a separating membrane interposed between the two electrodes. The positive electrode electrolyte contains a manganese ion and an additional metal ion, the negative electrode electrolyte contains at least one metal ion selected from a titanium ion, a vanadium ion, a chromium ion, and a zinc ion, and the additional metal ion contained in the positive electrode electrolyte is at least one of an aluminum ion, a cadmium ion, an indium ion, a tin ion, an antimony ion, an iridium ion, a gold ion, a lead ion, a bismuth ion, and a magnesium ion.

Abstract: An electrolyte for a redox flow battery has a total concentration of arsenic ions and antimony ions of 15 mass ppm or less. In an example of the electrolyte for a redox flow battery, preferably, the concentration of the arsenic ions is 10 mass ppm or less. In another example of the electrolyte for a redox flow battery, preferably, the concentration of the antimony ions is 10 mass ppm or less.

Abstract: Provided is an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of precipitate during a battery reaction. In the electrolyte for a redox flow battery, the total concentration of impurity element ions contributing to generation of precipitate during a battery reaction is 220 mass ppm or less. In a case where the impurity element ions contributing to generation of precipitate include metal element ions, the total concentration of the metal element ions may be 195 mass ppm or less. In a case where the impurity element ions contributing to generation of precipitate include non-metal element ions, the total concentration of the non-metal element ions may be 21 mass ppm or less.

Abstract: Provided is an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of precipitate during a battery reaction. In the electrolyte for a redox flow battery, the total concentration of impurity element ions contributing to generation of precipitate during a battery reaction is 220 mass ppm or less. In a case where the impurity element ions contributing to generation of precipitate include metal element ions, the total concentration of the metal element ions may be 195 mass ppm or less. In a case where the impurity element ions contributing to generation of precipitate include non-metal element ions, the total concentration of the non-metal element ions may be 21 mass ppm or less.