# US 2013/0157162 A1 · Redox flow battery and method of operating the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157162 A1 - Document ID: US20130157162A1 - Status: Published application - Kind: A1 - Application number: 13/638,323 - Filed: 2011-11-10 - Published: 2013-06-20 - Earliest claimed: 2011-03-25 - Assignees: Sumitomo Electric Industries, Ltd. - Inventors: Yongrong Dong; Toshio Shigematsu; Takahiro Kumamoto - Web page: https://patentgrep.com/patent/US20130157162A1 ## CPC - H01M 8/20: Indirect fuel cells, e.g. fuel cells with redox couple being irreversible (H01M8/18 takes precedence) - H01M 8/04089: of gaseous reactants - H01M 8/04753: {of fuel cell reactants} - H01M 8/04761: {of fuel cell exhausts} - H01M 8/188: {by recharging of redox couples containing fluids; Redox flow type batteries} - H01M 8/04798: {of fuel cell reactants} - H01M 8/04805: {of fuel cell exhausts} - Y02E 60/50: Fuel cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A redox flow battery in which a positive electrode electrolyte stored in a positive electrode tank and a negative electrode electrolyte stored in a negative electrode tank are supplied to a battery element to charge and discharge the battery is provided, the positive electrode electrolyte in the redox flow battery containing a Mn ion as a positive electrode active material, the negative electrode electrolyte containing at least one of a Ti ion, a V ion, and a Cr ion as a negative electrode active material, in which the redox flow battery includes a negative-electrode-side introduction duct in communication with inside of the negative electrode tank from outside thereof, for introducing oxidizing gas into the negative electrode tank, and a supply mechanism for supplying the oxidizing gas into the negative electrode tank via the negative-electrode-side introduction duct. ## Claims ### Claim 1 A redox flow battery in which a positive electrode electrolyte stored in a positive electrode tank and a negative electrode electrolyte stored in a negative electrode tank are supplied to a battery element including a positive electrode, a negative electrode, and a membrane interposed between these electrodes, to charge and discharge the battery, said positive electrode electrolyte containing a Mn ion as a positive electrode active material, said negative electrode electrolyte containing at least one of a Ti ion, a V ion, and a Cr ion as a negative electrode active material, said redox flow battery comprising: a negative-electrode-side introduction duct in communication with inside of said negative electrode tank from outside thereof, for introducing oxidizing gas into said negative electrode tank; and a negative-electrode-side supply mechanism for supplying said oxidizing gas into said negative electrode tank via said negative-electrode-side introduction duct. ### Claim 2 (depends on 1) The redox flow battery according to claim 1, wherein said oxidizing gas contains oxygen. ### Claim 3 (depends on 1) The redox flow battery according to claim 1, comprising a gas-phase communicating tube bringing a gas phase of said positive electrode tank in communication with a gas phase of said negative electrode tank. ### Claim 4 (depends on 1) The redox flow battery according to claim 1, comprising a monitor mechanism for monitoring a state of charge of said redox flow battery. ### Claim 5 (depends on 1) The redox flow battery according to claim 1, wherein said negative-electrode-side introduction duct opens into a liquid phase of said negative electrode tank. ### Claim 6 (depends on 1) The redox flow battery according to claim 1, comprising an agitation mechanism provided in said negative electrode tank for agitating said negative electrode electrolyte. ### Claim 7 (depends on 1) The redox flow battery according to claim 1, wherein said positive electrode electrolyte contains a Ti ion. ### Claim 8 (depends on 7) The redox flow battery according to claim 7, wherein said negative electrode electrolyte contains a Ti ion as the negative electrode active material, and further contains a Mn ion. ### Claim 9 (depends on 8) The redox flow battery according to claim 8, comprising a liquid-phase communicating tube bringing a liquid phase of said positive electrode tank in communication with a liquid phase of said negative electrode tank. ### Claim 10 (depends on 9) The redox flow battery according to claim 9, comprising: a positive-electrode-side introduction duct in communication with inside of said positive electrode tank from outside thereof, for introducing oxidizing gas into said positive electrode tank; and a positive-electrode-side supply mechanism for supplying said oxidizing gas into said positive electrode tank via said positive-electrode-side introduction duct. ### Claim 11 (depends on 1) A method of operating a redox flow battery using the redox flow battery according to claim 1, comprising the step of introducing said oxidizing gas into said negative electrode tank in order to oxidize the negative electrode active material contained in said negative electrode electrolyte. ### Claim 12 (depends on 11) The method of operating a redox flow battery according to claim 11, wherein said oxidizing gas is introduced when a difference in state of charge occurs between said positive electrode electrolyte and said negative electrode electrolyte. ### Claim 13 (depends on 12) The method of operating a redox flow battery according to claim 12, wherein the states of charge of said positive electrode electrolyte and said negative electrode electrolyte are nearly equalized with each other by controlling an amount of said oxidizing gas to be introduced. ### Claim 14 (depends on 13) The method of operating a redox flow battery according to claim 13, wherein a degree of transparency of said negative electrode electrolyte is used as a criterion for controlling said amount to be introduced. ### Claim 15 (depends on 11) The method of operating a redox flow battery according to claim 11, wherein the operation is performed while a state of charge of said redox flow battery is monitored.