Abstract: Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, may be 610 mg/L or less and a concentration of vanadium ions may be 1 mol/L or more and 3 mol/L or less.

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: Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, may be 610 mg/L or less and a concentration of vanadium ions may be 1 mol/L or more and 3 mol/L or less.

Abstract: Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 610 mg/L or less, a concentration of vanadium ions is 1 mol/L or more and 3 mol/L or less, a concentration of free sulfuric acid is 1 mol/L or more and 4 mol/L or less, a concentration of phosphoric acid is 1.0×10?4 mol/L or more and 7.1×10?1 mol/L or less, a concentration of ammonium is 20 mg/L or less, and a concentration of silicon is 40 mg/L or less.

Abstract: A redox flow battery electrode includes a substrate and a catalytic unit supported on the substrate. The substrate contains at least one element selected from the group consisting of C, Ti, Sn, Ta, Ce, In, W, and Zn, and the catalytic unit contains at least one element selected from the group consisting of Fe, Si, Mo, Ce, Mn, Cu, and W.

Abstract: Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 610 mg/L or less, a concentration of vanadium ions is 1 mol/L or more and 3 mol/L or less, a concentration of free sulfuric acid is 1 mol/L or more and 4 mol/L or less, a concentration of phosphoric acid is 1.0×10?4 mol/L or more and 7.1×10?1 mol/L or less, a concentration of ammonium is 20 mg/L or less, and a concentration of silicon is 40 mg/L or less.

Abstract: Provided is an electrolyte flow battery system including a gas supply mechanism that always continuously supplies a flow gas containing an inert gas to a gas phase in a tank that stores an electrolyte. In the electrolyte, the total concentration of ions of elements in groups 1 to 8 and 13 to 16 in the fifth period and groups 1, 2, 4 to 8, and 13 to 15 in the sixth period of a periodic table is 2,500 mg/L or less. The generation rate of hydrogen is less than 95 cc/h/m2 when a charge and discharge test is performed while the electrolyte is circulated and supplied to an electrolyte flow battery. The flow rate of the flow gas is 1.0 L/min or more and 50 L/min or less.

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: 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.

Abstract: Provided are an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of hydrogen during a battery reaction; and a redox flow battery including the electrolyte. In the electrolyte for a redox flow battery, the total concentration of platinum-group element ions is 4.5 mass ppm or less. The platinum-group element ions may satisfy in terms of concentration at least one of those described below: the concentration of rhodium ions is 1 mass ppm or less, the concentration of palladium ions is 1 mass ppm or less, the concentration of iridium ions is 1 mass ppm or less, and the concentration of platinum ions is 1 mass ppm or less.

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 are an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of precipitate and suppression of generation of hydrogen during a battery reaction; and a redox flow battery including the electrolyte. 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, and the total concentration of platinum-group element ions is 4.5 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.

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: Provided are an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of precipitate and suppression of generation of hydrogen during a battery reaction; and a redox flow battery including the electrolyte. 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, and the total concentration of platinum-group element ions is 4.5 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.

Abstract: Provided are an electrolyte for a redox flow battery, the electrolyte allowing suppression of generation of hydrogen during a battery reaction; and a redox flow battery including the electrolyte. In the electrolyte for a redox flow battery, the total concentration of platinum-group element ions is 4.5 mass ppm or less. The platinum-group element ions may satisfy in terms of concentration at least one of those described below: the concentration of rhodium ions is 1 mass ppm or less, the concentration of palladium ions is 1 mass ppm or less, the concentration of iridium ions is 1 mass ppm or less, and the concentration of platinum ions is 1 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.