WO2022270108A1 - Système de batterie à flux redox - Google Patents

Système de batterie à flux redox Download PDF

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Publication number
WO2022270108A1
WO2022270108A1 PCT/JP2022/015672 JP2022015672W WO2022270108A1 WO 2022270108 A1 WO2022270108 A1 WO 2022270108A1 JP 2022015672 W JP2022015672 W JP 2022015672W WO 2022270108 A1 WO2022270108 A1 WO 2022270108A1
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electrolyte
positive electrode
negative electrode
state
cell
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PCT/JP2022/015672
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English (en)
Japanese (ja)
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恭裕 内藤
宏一 加來
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住友電気工業株式会社
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Publication of WO2022270108A1 publication Critical patent/WO2022270108A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/04537—Electric variables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
    • H01M8/04858—Electric variables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/18—Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present disclosure relates to redox flow battery systems.
  • This application claims priority based on Japanese Patent Application No. 2021-102300 filed in Japan on June 21, 2021, and incorporates all the content described in the Japanese application.
  • Patent Document 1 discloses a manganese-titanium redox flow battery using a positive electrode electrolyte containing manganese ions and a negative electrode electrolyte containing titanium ions. If manganese ions are contained in the positive electrode electrolyte, manganese oxide (MnO 2 ) may precipitate during charging and discharging. Patent document 1 suppresses deposition of manganese oxide by containing titanium ions in addition to manganese ions in the positive electrode electrolyte.
  • the redox flow battery system of the present disclosure comprises bank and a controller that controls the state of charge of the bank;
  • the bank is a battery cell; a positive electrode tank in which a positive electrode electrolyte circulating in the battery cell is stored; a negative electrode tank in which a negative electrode electrolyte circulating in the battery cell is stored;
  • a power conversion device that controls charging and discharging of the battery cell The controller comprises a first controller that controls the power conversion device so that the state of charge of the battery cell is held in a specific state for 10 seconds or more, The specific state is at least one of a first state and a second state,
  • the first state is a state in which the state of charge of the electrolyte in the battery cell differs from the state of charge of the positive electrode electrolyte in the positive electrode tank by 5% or more
  • the second state is a state in which the charge state of the electrolyte in the battery cell differs from the charge state of the negative electrode electrolyte in the negative electrode tank by 5% or more
  • FIG. 1 is a schematic configuration diagram showing the basic configuration of the redox flow battery system of the embodiment.
  • FIG. 2 is a schematic configuration diagram showing a state during normal operation in the redox flow battery system of Embodiment 1-1.
  • FIG. 3 is a schematic configuration diagram showing the state of the redox flow battery system of Embodiment 1-1 during recovery work of the electrolytic solution.
  • FIG. 4 is a schematic configuration diagram showing a state during normal operation in the redox flow battery system of Embodiment 1-2.
  • FIG. 5 is a schematic diagram showing the state of the redox flow battery system of Embodiment 1-2 during recovery work of the electrolytic solution.
  • FIG. 6 is a schematic configuration diagram showing the configuration of the redox flow battery system of Embodiment 2.
  • FIG. 7 is a schematic configuration diagram showing the configuration of the redox flow battery system of Embodiment 3.
  • FIG. 8 is a schematic configuration diagram showing the configuration of the redox flow battery system of Embodiment 4.
  • Redox flow battery systems are required to have higher energy densities. If the energy density can be increased, the battery capacity can be increased.
  • One of the means to increase the energy density of the redox flow battery is to expand the range of utilization of the state of charge (SOC) of the electrolyte. However, with the expansion of the range of utilization of SOC, side reactions such as deposition of oxides are likely to occur within the battery cells constituting the redox flow battery.
  • SOC state of charge
  • a by-reactant generated in the battery cell adheres to the electrode, for example. Adhesion of the by-reactants to the electrode reduces the performance of the electrode and adversely affects the battery performance.
  • One of the purposes of the present disclosure is to provide a redox flow battery system that can improve battery performance degradation due to side reactions while achieving high energy density.
  • the redox flow battery system of the present disclosure can improve battery performance degradation due to side reactions while achieving high energy density.
  • a redox flow battery system bank and a controller that controls the state of charge of the bank;
  • the bank is a battery cell; a positive electrode tank in which a positive electrode electrolyte circulating in the battery cell is stored; a negative electrode tank in which a negative electrode electrolyte circulating in the battery cell is stored;
  • a power conversion device that controls charging and discharging of the battery cell,
  • the controller comprises a first controller that controls the power conversion device so that the state of charge of the battery cell is held in a specific state for 10 seconds or more,
  • the specific state is at least one of a first state and a second state
  • the first state is a state in which the state of charge of the electrolyte in the battery cell differs from the state of charge of the positive electrode electrolyte in the positive electrode tank by 5% or more
  • the second state is a state in which the charge state of the electrolyte in the battery cell differs from the charge state of the negative electrode electrolyte in the negative electrode tank by 5% or more.
  • the charged state of the battery cells is maintained in a specific state for 10 seconds or longer, thereby redissolving the by-reactants generated in the battery cells.
  • the redox flow battery system of the present disclosure can re-dissolve the side-reactant even if the side-reactant is generated in the battery cell to restore the performance of the electrode. Since the redox flow battery system of the present disclosure is capable of recovering the electrolytic solution by redissolving the by-reactant, it is possible to expand the usage range of the state of charge of the electrolytic solution. As described above, the redox flow battery system of the present disclosure can improve battery performance degradation due to side reactions while achieving high energy density.
  • redissolving the side reaction product is broadly defined as restoring the state of the electrolytic solution, which has changed due to charging or discharging within a specific SOC range, to its original state.
  • This definition is not limited to converting solid deposits back into ions in the electrolyte.
  • This definition includes with or without a gas/solid/liquid phase change.
  • an electrolytic solution containing a solid active material such as zinc it also includes controlling the amount of electrodeposition.
  • An active material may deposit on the surface of an electrode by a side reaction. When deposits from side reactions adhere to the electrode, the reactivity of the electrode deteriorates. That is, the battery performance is degraded.
  • a catalyst or the like may be adhered to the surface of the electrode. Even if the deposit due to the side reaction deposits so as to cover the catalyst and the like, the performance of the battery is lowered. By re-dissolving the precipitate adhering to the surface of the electrode, the condition of the surface of the electrode can be maintained. Thereby, deterioration of battery performance can be suppressed.
  • the specific state may be maintained for 10 minutes or less.
  • Charging or discharging during normal operation means expanding the usage range of the state of charge of the electrolyte beyond the usage range of the main SOC, which will be described later, so that the redox flow battery system is connected to an external power source or load. It is the charging or discharging that occurs.
  • the operation may be restricted, such as stopping the normal operation of the redox flow battery system.
  • the by-reactants generated in the battery cells can be redissolved, and the effects on the normal operation of the redox flow battery system can be suppressed in a short period of time.
  • the battery cell includes a positive electrode cell and a negative electrode cell, a first positive electrode circuit for returning the positive electrode electrolyte from the positive electrode tank to the positive electrode tank through the positive electrode cell; a first negative electrode circulation path returning the negative electrode electrolyte from the negative electrode tank to the negative electrode tank through the negative electrode cell; a second positive electrode circuit for returning the positive electrode electrolyte from the positive electrode tank to the positive electrode tank via the negative electrode cell; and a second positive electrode circuit for returning the negative electrode electrolyte from the negative electrode tank to the negative electrode tank via the positive electrode cell.
  • the controller may include a second controller that controls the operation of the first switching section or the second switching section.
  • the first positive electrode circuit circulates the positive electrode electrolyte to the positive electrode cell
  • the first negative electrode circuit circulates the negative electrode electrolyte to the negative electrode cell.
  • the electrolyte solution of opposite polarity is circulated through the positive electrode cell or the negative electrode cell.
  • the second negative electrode circuit circulates the negative electrode electrolyte in the positive electrode cell.
  • the second positive electrode circuit circulates the positive electrode electrolyte in the negative electrode cell.
  • the controller performs charging or discharging such that the difference between the charged state at the inlet side of the electrolyte supplied to the battery cell and the charged state at the outlet side of the electrolyte discharged from the battery cell is 10% or more.
  • a third controller may be provided that controls the power conversion device to perform
  • the equipment used in the normal operation of the redox flow battery system can be used as it is, or the above equipment can be used with a simple modification to reduce the amount of electrolyte in the battery cell.
  • the charging state can be set to a specific state.
  • the third controller may control the power converter so that the charging or discharging is performed at a current density of 300 mA/cm 2 or higher.
  • Charging or discharging at a current density of 300 mA/cm 2 or higher tends to bring the state of charge of the electrolyte in the battery cell into a specific state.
  • the third controller controls the charging or discharging when the flow rate of the electrolytic solution supplied to the battery cell is 4.0 cc/min/cm 2 or less. You may control the said power converter to perform.
  • the first state is a state in which the state of charge of the electrolyte in the battery cell differs from the state of charge of the positive electrode electrolyte in the positive electrode tank by 15% or more
  • the second state may be a state in which the charge state of the electrolyte in the battery cell differs from the charge state of the negative electrode electrolyte in the negative electrode tank by 15% or more.
  • a plurality of the banks are provided,
  • the controller controls the power conversion device provided in each of the plurality of banks so that the state of charge of the battery cells provided in each of the plurality of banks sequentially becomes the specific state among the plurality of banks.
  • a rotating controller may be provided.
  • the controller includes a rotatable controller
  • the rotatable controller can cause the battery cells in each bank to be placed in a particular state in sequence from bank to bank. Specifically, in the bank where the recovery work of the electrolyte in the battery cell is performed, the state of charge of the electrolyte in the battery cell can be set to a specific state. On the other hand, in the bank in which the recovery work of the electrolyte in the battery cell is not performed, the state of charge of the electrolyte in the battery cell can be brought to the state of normal operation. In other words, the rotatable controller enables recovery of the electrolyte in the battery cells without stopping the normal operation of the redox flow battery system.
  • the RF battery system 1 of the embodiment includes a bank 2 and a controller 9 that controls the SOC of the bank 2, as shown in FIG.
  • Bank 2 includes battery cells 10 , positive electrode tank 22 , negative electrode tank 23 , and power conversion device 8 .
  • One or a plurality of banks 2 are provided.
  • the controller 9 has a first controller 91 .
  • the first controller 91 controls the power conversion device 8 so that the SOC of the battery cell 10 is held in a specific state for 10 seconds or longer.
  • the specific state is at least one of the first state and the second state.
  • the first state is a state in which the SOC of the electrolyte in the battery cell 10 differs from the SOC of the cathode electrolyte in the cathode tank 22 by 5% or more.
  • the second state is a state in which the SOC of the electrolyte in the battery cell 10 differs from the SOC of the anode electrolyte in the anode tank 23 by 5% or more.
  • the RF battery system 1 is typically connected to an external power supply 810 and load 820 via a substation facility 800 .
  • the RF battery system 1 can charge power supplied from the power supply 810 and discharge the charged power to the load 820 .
  • the power source 810 is, for example, power generation equipment using natural energy such as solar power generation or wind power generation, or other general power plants.
  • the load 820 is, for example, a power system or a power consumer.
  • the RF battery system 1 is used, for example, for load leveling, momentary sag compensation, emergency power supply, and output smoothing of natural energy power generation.
  • the range of utilization of the state of charge of the electrolytic solution is expanded to the range of utilization of the main SOC, which will be described later, plus the range of utilization of the sub-SOC.
  • the operation of the RF battery system 1 that is expanded and charged or discharged is called normal operation.
  • ⁇ bank ⁇ Bank 2 is a secondary battery unit system that charges or discharges a power system.
  • the bank 2 includes battery cells 10 , a circulation mechanism that circulates an electrolytic solution in the battery cells 10 , and a power converter 8 that controls charging and discharging of the battery cells 10 .
  • the bank 2 is charged or discharged by circulating the electrolyte in the battery cells 10 .
  • charging and discharging of the battery cells 10 of each bank 2 are independently controlled by each power conversion device 8 .
  • a battery cell 10 is separated into a positive electrode cell 12 and a negative electrode cell 13 by a diaphragm 11 .
  • a positive electrode 14 is incorporated in the positive electrode cell 12 .
  • a positive electrode electrolyte is supplied to the positive electrode cell 12 .
  • a negative electrode 15 is incorporated in the negative electrode cell 13 .
  • a negative electrode electrolyte is supplied to the negative electrode cell 13 .
  • the battery cells 10 are typically used in a form called a cell stack 200 in which a plurality of battery cells 10 are stacked.
  • the cell stack 200 includes a cell frame 100, a positive electrode 14, a diaphragm 11, a negative electrode 15, and another cell frame 100, which are repeatedly stacked, two end plates 201 sandwiching the stack, and a fastening member 202.
  • the tightening member 202 is, for example, a long bolt and nut.
  • the two end plates 201 are clamped by clamping members 202 . By this tightening, the laminated state of the laminated body is maintained.
  • the cell stack 200 is typically used in a form in which a predetermined number of battery cells 10 are used as substacks (not shown), and a plurality of substacks are stacked.
  • Supply/discharge plates (not shown) are arranged outside the cell frames 100 positioned at both ends in the stacking direction of the battery cells 10 in the sub-stack or cell stack 200 .
  • the cell frame 100 includes a frame 110 and a bipolar plate 112.
  • Frame 110 is provided on the outer periphery of bipolar plate 112 .
  • a positive electrode 14 and a negative electrode 15 are housed inside the frame 110 with a bipolar plate 112 interposed therebetween.
  • One battery cell 10 is configured by arranging the positive electrode 14 and the negative electrode 15 between the bipolar plates 112 of the adjacent cell frames 100 with the diaphragm 11 interposed therebetween.
  • a sealing member 150 is arranged between the frames 110 to prevent the electrolyte from leaking from the battery cells 10 .
  • the circulation mechanism includes a positive electrode circulation mechanism that circulates the positive electrode electrolyte in the positive electrode cells 12 and a negative electrode circulation mechanism that circulates the negative electrode electrolyte in the negative electrode cells 13 .
  • the positive electrode circulation mechanism includes a positive electrode tank 22 , an outward pipe 24 , a return pipe 26 and a pump 28 .
  • a positive electrode electrolyte is stored in the positive electrode tank 22 .
  • Outbound pipe 24 and return pipe 26 connect between positive electrode tank 22 and positive electrode cell 12 .
  • a pump 28 is provided in the forward line 24 on the supply side.
  • the negative electrode circulation mechanism includes a negative electrode tank 23 , an outward pipe 25 , a return pipe 27 and a pump 29 .
  • a negative electrode electrolyte is stored in the negative electrode tank 23 .
  • Outbound pipe 25 and return pipe 27 connect between negative electrode tank 23 and negative electrode cell 13 .
  • the pump 29 is provided in the outward line pipe 25 on the supply side.
  • the positive electrode electrolyte is supplied from the positive electrode tank 22 to the positive electrode cell 12 through the outbound pipe 24 and returned from the positive electrode cell 12 to the positive electrode tank 22 through the return pipe 26 .
  • the negative electrode electrolyte is supplied from the negative electrode tank 23 to the negative electrode cell 13 through the forward pipe 25 and returned from the negative electrode cell 13 to the negative electrode tank 23 through the return pipe 27 .
  • the electrolytic solution is a solution containing active material ions.
  • An active material ion is an ion that functions as an active material.
  • Active material ions are typically metal ions whose valences change due to oxidation-reduction.
  • Active material ions are, for example, ions of elements selected from the group consisting of manganese, vanadium, iron, chromium, titanium, and zinc.
  • At least one of the positive electrode electrolyte and the negative electrode electrolyte has the following characteristics. (1) Depending on the SOC range during charging or discharging, a side reaction occurs and a side reaction product is produced. (2) It is possible to redissolve the side reactants by a reversible reaction.
  • a side reaction product produced by a side reaction is, for example, a deposit of active material ions.
  • the electrolytic solution is, for example, an electrolytic solution containing manganese ions.
  • the manganese ions may precipitate as manganese oxide in the electrolyte in the high SOC region during charging.
  • Manganese oxide can be decomposed into manganese ions and redissolved in the electrolytic solution by the recovery operation of the electrolytic solution, which will be described later.
  • the positive electrode electrolyte is an electrolyte containing manganese ions
  • the negative electrode electrolyte is an electrolyte containing titanium ions, for example.
  • the power conversion device 8 controls charging and discharging of the battery cells 10 .
  • the battery cells 10 are charged and discharged via the power conversion device 8 .
  • the charging and discharging of the battery cells 10 of each bank 2 are independently controlled by the power conversion device 8 of each bank 2 .
  • an AC/DC converter can be used as the power conversion device 8 .
  • Controller 9 controls the SOC of bank 2 .
  • the SOC of bank 2 is the SOC of the electrolyte in the battery cell 10 in bank 2 .
  • the controller 9 controls the power conversion device 8 of each bank 2 to control the SOC of each bank 2 .
  • the controller 9 includes a basic controller 90 that controls the power conversion device 8 so that the battery cells 10 are charged or discharged within the expanded range of the main SOC.
  • the basic controller 90 operates during normal operation of the RF battery system 1 . During normal operation, the power system connected to the power supply 810 and the load 820 is charged or discharged.
  • the controller 9 includes a first controller 91 that controls the power converter 8 so that the SOC of the battery cell 10 is held in a specific state for 10 seconds or longer.
  • the first controller 91 operates during recovery work of the electrolyte in the bank 2 .
  • the work of recovering the electrolyte in bank 2 is to re-dissolve the side reaction products generated in the battery cells 10 in bank 2 .
  • Side reactants are produced within the battery cells 10 during normal operation of the RF battery system 1 .
  • the side reactants adhere to constituent members within the battery cell 10, such as electrodes.
  • the battery cells 10 forming the bank 2 do not charge or discharge the electric power system.
  • the controller 9 issues a command to the power conversion device 8 of bank 2.
  • the controller 9 issues commands to the power converters 8 of each bank 2 .
  • the power conversion device 8 of bank 2 controls charging and discharging of the battery cells 10 based on commands from the controller 9 .
  • the controller 9 causes the basic controller 90 to control the power conversion device so that the battery cells 10 are charged or discharged at an SOC within an expanded range of the main SOC.
  • Command 8 When the controller 9 does not charge or discharge the electric power system and restores the electrolyte in the bank 2, the first controller 91 keeps the SOC of the battery cell 10 in a specific state for 10 seconds or more.
  • a command is issued to the power conversion device 8 so that the
  • a computer for example, can be used as the controller 9.
  • a computer includes a processor, memory, timers, and the like.
  • the memory stores a control program to be executed by the processor and various data.
  • the processor reads and executes the control program stored in the memory.
  • the program contains instructions for processing by controller 9 .
  • the SOC of the battery cell 10 differs during normal operation of the RF battery system 1 and during recovery work of the electrolyte.
  • the SOC of the battery cell 10 here is the average value of the SOC on the inlet side of the electrolyte supplied to the battery cell 10 and the SOC on the outlet side of the electrolyte discharged from the battery cell 10 .
  • ⁇ be the SOC on the inlet side of the electrolyte supplied to the battery cell 10 .
  • ⁇ be the SOC on the outlet side of the electrolyte discharged from the battery cell 10 .
  • the average value of the SOC of the battery cells 10 is a value obtained by ( ⁇ + ⁇ )/2.
  • the inlet-side SOC of the electrolytic solution supplied to the battery cell 10 is the SOC of the electrolytic solution flowing through the forward pipes 24 and 25 .
  • the outlet-side SOC of the electrolyte discharged from the battery cell 10 is the SOC of the electrolyte flowing through the return pipes 26 and 27 .
  • the main SOC utilization range is the SOC range in which side reactions are less likely to occur and side reaction products are less likely to be generated.
  • the range of SOC in which side reaction products are less likely to be generated is, for example, the total amount of elements that become active materials contained in the electrolytic solution when charging and discharging for one week within a certain SOC range is set to 100 mol%. In this case, the ratio of the active material consumed in the production of the by-reactant is 10 mol % or less.
  • the period of charging and discharging within the above SOC range may be two weeks, or even one month.
  • the ratio of the active material consumed in the production of the above side reaction products is preferably 5 mol % or less, more preferably 1 mol % or less.
  • a positive electrode electrolyte containing manganese ions as an active material when manganese oxide is produced as a side-reactant, manganese is consumed in the production of the side-reactant.
  • the expanded range of usage of the main SOC includes, in addition to the range of usage of the main SOC, the range of sub-SOC where side reactions occur due to charging and discharging and side reactants are generated.
  • the sub-SOC range includes at least one of the high SOC region and the low SOC region.
  • the high SOC region is a region in which the SOC is higher than the upper limit of the main SOC utilization range.
  • the low SOC region is a region in which the SOC is lower than the lower limit of the main SOC utilization range. Side reactants may be generated in the high SOC region and the low SOC region.
  • the usable range of the main SOC varies depending on the electrolyte used.
  • the usable range of the main SOC is determined in advance by a test using the electrolytic solution to be used.
  • a range that is wider than the range of utilization of the main SOC, that is, each range of the high SOC region and the low SOC region may be set as appropriate.
  • the range of the high SOC region or the range of the low SOC region is, for example, 5% or more, further 10% or more, particularly 15% or more of the size of the main SOC utilization range.
  • the size of the utilization range is the difference between the upper limit and the lower limit of the utilization range.
  • the main SOC utilization range is 20% to 80%.
  • the range of the high SOC region is 10% of the size of the available range
  • the SOC utilization range combining the main SOC utilization range and the high SOC region is from 20% to 86%.
  • the SOC utilization range is expanded by 10% from the main SOC utilization range, so the battery capacity of bank 2 is increased by 10%.
  • the range of the low SOC region is 10% of the size of the usable range
  • the usable range of SOC is from 14% to 80%. In this case as well, the battery capacity of bank 2 will increase by 10%.
  • the electrolytic solution may be, for example, a vanadium-based electrolytic solution.
  • both the positive electrode electrolyte and the negative electrode electrolyte contain vanadium ions.
  • the vanadium ions in the positive electrode electrolyte and the vanadium ions in the negative electrode electrolyte have different valences.
  • the main SOC utilization range is approximately 5% to 95%.
  • the range obtained by adding the usage range of the sub SOC to the usage range of the main SOC is the SOC range of the battery cell 10 during normal operation.
  • the SOC of the electrolyte in the battery cell 10 is substantially the same as the SOC of the cathode electrolyte in the cathode tank 22 and the SOC of the anode electrolyte in the anode tank 23. is substantially the same as “Substantially the same” means that the difference between the SOC of the electrolyte in the battery cell 10 and the SOC of the cathode electrolyte in the cathode tank 22 is less than 5%, and the SOC of the electrolyte in the battery cell 10 and the anode It means that the difference from the SOC of the negative electrode electrolyte in the tank 23 is less than 5%.
  • the SOC of the battery cells 10 is controlled to a specific state by the first controller 91 during the recovery work of the electrolyte in the bank 2 .
  • the specific state is at least one of the first state and the second state.
  • the first state is a state in which the SOC of the electrolyte in the battery cell 10 differs from the SOC of the cathode electrolyte in the cathode tank 22 by 5% or more.
  • the second state is a state in which the SOC of the electrolyte in the battery cell 10 differs from the SOC of the anode electrolyte in the anode tank 23 by 5% or more.
  • the side-reactant may be re-dissolved in a region lower than the main SOC utilization range.
  • the area where the SOC is lower than the main SOC utilization range includes a low SOC area and an area where the SOC is even lower than the low SOC area. If a side-reactant is produced in the low SOC region, the side-reactant may be re-dissolved in the higher SOC region than the main SOC utilization range.
  • the area where the SOC is higher than the main SOC utilization range includes a high SOC area and an area where the SOC is higher than the high SOC area.
  • the difference may be 8% or more, 10% or more, 12% or more, 15% or more.
  • the difference may be 50% or more, 100% or more, or 150% or more.
  • the above difference is less than 200%, even less than 180%, especially less than 170%, less than 160%.
  • the difference is, for example, 5% or more and less than 200%, 50% or more and 180% or less, 100% or more and 170% or less, or 150% or more and 160% or less.
  • the above difference is 50% or less, and further 45% due to the use of the RF battery system 1. below, especially below 40%.
  • the difference is, for example, 5% or more and 50% or less, 8% or more and 50% or less, 10% or more and 50% or less, 12% or more and 45% or less, 15% or more and 40%. % or less.
  • the time for which the SOC of the battery cell 10 is held in the specific state is 10 seconds or longer.
  • the side reaction product can be redissolved.
  • the longer the time the easier it is to re-dissolve the side reaction product.
  • the time may also be 30 seconds or more, 1 minute or more, 2 minutes or more, especially 3 minutes or more.
  • the above time is, for example, 10 minutes or less. If the SOC of the battery cell 10 is in the specific state, the by-reactant generated in the battery cell 10 can be redissolved even in a short time of 10 minutes or less.
  • the time is, for example, 10 seconds or more and 10 minutes or less, further 30 seconds or more and 10 minutes or less, 1 minute or more and 10 minutes or less, 2 minutes or more and 10 minutes or less, particularly 3 minutes or more and 10 minutes or less.
  • the SOC of the electrolyte in the battery cell 10, that is, the SOC of the battery cell 10, is the SOC at the inlet side of the electrolyte supplied to the battery cell 10 and the SOC at the outlet of the electrolyte discharged from the battery cell 10, as described above. It is the average value with the SOC on the side.
  • the inlet-side SOC can be measured, for example, by using a monitor cell to which the same electrolytic solution as that supplied to the battery cell 10 is supplied.
  • the electrolyte supplied to the battery cells 10 and the electrolyte supplied to the monitor cells are supplied from the same tank.
  • the SOC on the inlet side is measured using a monitor cell 60 configured by a part of the cells of the cell stack 200.
  • FIG. The monitor cell 60 does not charge or discharge.
  • a monitor cell 61 different from the cell stack 200 is used to measure the SOC on the inlet side.
  • the monitor cell 61 is provided upstream of the battery cell 10 .
  • the monitor cell 61 is connected to branch pipes provided in each of the forward pipe 24 through which the positive electrode electrolyte flows and the forward pipe 25 through which the negative electrode electrolyte is flowed.
  • the monitor cell 61 does not charge or discharge.
  • the monitor cells 60 and 61 can obtain the SOC from their open circuit voltage (OCV: Open Circuit Voltage) using a voltmeter.
  • OCV Open Circuit Voltage
  • Embodiment 1 instead of the monitor cell 60, a monitor cell 61 similar to that of Embodiments 2 and 3 may be used to measure the inlet-side SOC. In Embodiments 2 and 3, instead of the monitor cell 61, a monitor cell 60 similar to that of Embodiment 1 may be used to measure the inlet-side SOC.
  • the SOC on the outlet side can be calculated from the SOC on the inlet side, the flow rate of the electrolyte flowing through the battery cell 10, and the current density of the electrolyte flowing through the battery cell 10.
  • the outlet-side SOC can also be measured using a monitor cell provided downstream of the battery cell 10 .
  • a monitor cell is provided downstream of the battery cell 10
  • this monitor cell is connected to branch pipes provided in each of the return pipe 26 through which the positive electrode electrolyte flows and the return pipe 27 through which the negative electrode electrolyte flows.
  • the inlet side When measuring the SOC on the outlet side using a monitor cell provided downstream of the battery cell 10, the measurement result, the flow rate of the electrolyte flowing through the battery cell 10, and the current density of the electrolyte flowing through the battery cell 10, the inlet side can also be calculated.
  • the SOC of the positive electrode electrolyte in the positive electrode tank 22 or the SOC of the negative electrode electrolyte in the negative electrode tank 23 can be calculated using the monitor cell that measures the SOC on the inlet side.
  • the monitor cell 60 is used for calculation.
  • ⁇ Means for setting the SOC of the battery cell to a specific state There are, for example, the following three forms of means for setting the SOC of the battery cell 10 to a specific state.
  • the first mode when the side reactant is generated in the high SOC region, the reverse polarity electrolyte is circulated to the positive electrode cell 12 or the negative electrode cell 13 where the side reactant is generated. be.
  • the second mode is a mode in which when a side reactant is generated in a high SOC region, the side reactant is redissolved by performing short-time discharge.
  • a third mode is a mode in which, when a side reactant is generated in a low SOC region, the side reactant is redissolved by charging for a short period of time.
  • the bank 2 includes a first positive electrode circuit 31, a first negative electrode circuit 41, and at least one of the second positive electrode circuit 32 and the second negative electrode circuit 42. and Moreover, in the first form, the bank 2 includes at least one of the first switching section and the second switching section.
  • the controller 9 comprises a second controller 92 that controls the operation of the first switching section or the second switching section.
  • the first positive electrode circulation path 31 is a circulation path that returns the positive electrode electrolyte from the positive electrode tank 22 to the positive electrode tank 22 via the positive electrode cell 12 .
  • the first positive electrode circulation path 31 corresponds to the outward piping 24 and the return piping 26 shown in FIG.
  • the first negative electrode circulation path 41 is a circulation path for returning the negative electrode electrolyte from the negative electrode tank 23 to the negative electrode tank 23 via the negative electrode cell 13 .
  • the first negative electrode circulation path 41 corresponds to the outward piping 25 and the return piping 27 shown in FIG. 2 to 5, the pumps 28, 29 shown in FIG. 1 are omitted.
  • the second positive electrode circulation path 32 is a circulation path that returns the positive electrode electrolyte from the positive electrode tank 22 to the positive electrode tank 22 via the negative electrode cell 13 .
  • the second negative electrode circulation path 42 is a circulation path that returns the negative electrode electrolyte from the negative electrode tank 23 to the negative electrode tank 23 via the positive electrode cell 12 .
  • the second positive electrode circuit 32 and the second negative electrode circuit 42 are not included in the basic configuration of the RF battery system 1 . Therefore, the second positive circuit 32 and the second negative circuit 42 are not shown in FIG.
  • the first switching section is a switching section that switches between the first positive electrode circulation path 31 and the second negative electrode circulation path 42 .
  • the first switching part is a valve.
  • the second switching section is a switching section that switches between the first negative electrode circulation path 41 and the second positive electrode circulation path 32 .
  • a second switching unit is a valve. The specific arrangement and number of valves will be described later.
  • the second controller 92 controls each valve to switch.
  • the controller 9 does not charge or discharge the electric power system such as the power supply 810 and the load 820, and when the recovery work of the electrolyte in the bank 2 is performed, the second controller 92 instructs to switch each valve. out.
  • the first controller 91 of the controller 9 issues a command to the power conversion device 8 so that the SOC of the battery cell 10 is held in a specific state for 10 seconds or longer.
  • each valve is switched to circulate the electrolyte solution of the opposite polarity for 10 seconds or more to the cell in which the side reaction product is generated among the positive electrode cell 12 and the negative electrode cell 13 .
  • the difference between the SOC of the electrolyte solution in the battery cell 10 and the SOC of the cathode electrolyte solution in the cathode tank 22 or the SOC of the anode electrolyte solution in the anode tank 23 is It is the difference between the SOC of one of the liquid and the negative electrode electrolyte and the SOC of the other.
  • the SOC of the positive electrode electrolyte and the negative electrode electrolyte is 80%, and the negative electrode electrolyte is circulated in the positive electrode cell 12, the SOC of the negative electrode electrolyte viewed from the SOC of the positive electrode electrolyte is ⁇ 80%. , the difference is 160%.
  • the first negative electrode circuit 41, the second positive electrode circuit 32, the second negative electrode circuit 42, the first switching unit, and the second switching unit piping and valves The number, position, etc. are changed. Two arrangements are described below.
  • Embodiment 1-1 the first arrangement mode will be described with reference to FIGS. 2 and 3.
  • FIG. both the second positive electrode circuit 32 and the second negative electrode circuit 42 are provided.
  • a main outbound pipe 33 and branch outbound pipes 34 a and 34 b are provided as pipes for supplying the positive electrode electrolyte from the positive electrode tank 22 to the battery cells 10 .
  • the main outbound pipe 33 is connected to the positive electrode tank 22 .
  • a pump (not shown) is provided in the main outbound pipe 33 .
  • the branch outbound pipe 34 a is connected to the main outbound pipe 33 and the positive electrode cell 12 .
  • a valve 37a is provided on the forward branch pipe 34a.
  • the outbound branch pipe 34 b is connected to the main outbound pipe 33 and the negative electrode cell 13 .
  • a valve 37b is provided on the forward branch pipe 34b.
  • a main return pipe 35 and branch return pipes 36 a and 36 b are provided as pipes for returning the positive electrode electrolyte from the battery cell 10 to the positive electrode tank 22 .
  • the main return pipe 35 is connected to the positive electrode tank 22 .
  • the branch return pipe 36 a is connected to the main return pipe 35 and the positive electrode cell 12 .
  • a valve 38a is provided in the branch return pipe 36a.
  • the branch return pipe 36 b is connected to the main return pipe 35 and the negative electrode cell 13 .
  • a valve 38b is provided in the branch return pipe 36b.
  • the valves 37a and 38a are opened in order to allow the positive electrode electrolyte to flow through the first positive electrode circulation path 31.
  • Valves 37b and 38b are closed.
  • the positive electrode electrolyte is supplied from the positive electrode tank 22 to the positive electrode cell 12 through the main outbound pipe 33 and the branched outbound pipe 34a, and from the positive electrode cell 12 to the branched return pipe 36a and the main return pipe 35. is returned to the positive electrode tank 22 through .
  • the valves 37b and 38b are opened in order to allow the positive electrode electrolyte to flow through the second positive electrode circulation path 32.
  • Valves 37a and 38a are closed.
  • the positive electrode electrolyte is supplied from the positive electrode tank 22 to the negative electrode cell 13 through the main outbound pipe 33 and the branched outbound pipe 34b. is returned to the positive electrode tank 22 through .
  • a main outbound pipe 43 and branch outbound pipes 44 a and 44 b are provided as pipes for supplying the negative electrode electrolyte from the negative electrode tank 23 to the battery cells 10 .
  • the main outbound pipe 43 is connected to the negative electrode tank 23 .
  • a pump (not shown) is provided in the main outbound pipe 43 .
  • the branch outbound pipe 44 a is connected to the main outbound pipe 43 and the negative electrode cell 13 .
  • a valve 47a is provided on the forward branch pipe 44a.
  • the branch outbound pipe 44 b is connected to the main outbound pipe 43 and the positive electrode cell 12 .
  • a valve 47b is provided on the forward branch pipe 44b.
  • a main return pipe 45 and branch return pipes 46 a and 46 b are provided as pipes for returning the negative electrode electrolyte from the battery cell 10 to the negative electrode tank 23 .
  • the main return pipe 45 is connected to the negative electrode tank 23 .
  • the branch return pipe 46 a is connected to the main return pipe 45 and the negative electrode cell 13 .
  • a valve 48a is provided in the branch return pipe 46a.
  • the branch return pipe 46 b is connected to the main return pipe 45 and the positive electrode cell 12 .
  • a valve 48b is provided in the branch return pipe 46b.
  • valves 47a and 48a are opened in order to allow the negative electrode electrolyte to flow through the first negative electrode circulation path 41.
  • Valve 47b and valve 48b are closed.
  • the negative electrode electrolyte is supplied from the negative electrode tank 23 to the negative electrode cell 13 through the main outbound pipe 43 and the branched outbound pipe 44a. is returned to the negative electrode tank 23 through .
  • valves 47b and 48b are opened in order to allow the negative electrode electrolyte to flow through the second negative electrode circuit 42.
  • Valve 47a and valve 48a are closed.
  • the negative electrode electrolyte is supplied from the negative electrode tank 23 to the positive electrode cell 12 through the main outbound pipe 43 and the branched outbound pipe 44b. is returned to the negative electrode tank 23 through .
  • valves 37a, 47b, 38a, and 48b are the first switching parts.
  • Valves 37b, 47a, 38b, and 48a are second switching units.
  • the second controller 92 circulates the positive electrode electrolyte in the positive electrode cell 12 and circulates the negative electrode electrolyte in the negative electrode cell 13. control the operation of the During normal operation of the RF battery system 1, the second controller 92 opens the valves 37a, 38a, 47a, 48a and closes the valves 37b, 38b, 47b, 48b.
  • a negative electrode electrolyte is circulated.
  • the white arrows shown in FIG. 2 indicate the flow of the electrolytic solution.
  • Thick-line pipes 33, 34a, 36a, and 35 shown in FIG. 2 are pipes through which the positive electrode electrolyte is distributed.
  • Thick-line pipes 43, 44a, 46a, and 45 shown in FIG. 2 are pipes through which the negative electrode electrolyte is distributed.
  • the second controller 92 circulates the electrolyte of opposite polarity to the positive electrode cell 12 and the negative electrode cell 13 in which the side reaction product is generated. It controls the operation of the switching unit or the second switching unit. For example, when a by-reactant is generated in the positive electrode cell 12 , the second controller 92 controls the operation of the first switching section so that the negative electrode electrolyte is circulated through the positive electrode cell 12 .
  • the second controller 92 switches between the valves 37a and 47b and switches between the valves 38a and 48b as a first switching unit that switches between the first positive electrode circulation path 31 and the second negative electrode circulation path 42 .
  • the second controller 92 opens the valves 47a, 48a, 47b, 48b and closes the valves 37a, 38a, 37b, 38b.
  • the negative electrode electrolyte is circulated to the negative electrode cell 13 by The white arrows shown in FIG. 3 indicate the flow of the electrolytic solution.
  • Thick-line pipes 43, 44a, 44b, 46a, 46b, and 45 shown in FIG. 3 are pipes through which the negative electrode electrolyte flows.
  • the negative electrode electrolyte is circulated in the positive electrode cell 12 in the recovery operation of the electrolyte in the bank 2, but the positive electrode electrolyte does not have to be circulated in the negative electrode cell 13. .
  • the second positive electrode circuit 32 shown in FIGS. 2 and 3 can be omitted.
  • the second controller 92 controls the operation of the second switching unit so that the positive electrode electrolyte is circulated through the negative electrode cell 13.
  • the second controller 92 switches between the valves 37b and 47a as a second switching unit for switching between the first negative electrode circuit 41 and the second positive electrode circuit 32, and switches between the valves 38b and 48a. switch.
  • the positive electrode electrolyte When a side reaction product is generated only in the negative electrode cell 13, the positive electrode electrolyte is circulated in the negative electrode cell 13 in the recovery operation of the electrolyte in the bank 2, but the negative electrode electrolyte does not have to be circulated in the positive electrode cell 12. .
  • the second negative electrode circuit 42 shown in FIGS. 2 and 3 can be omitted.
  • the positive electrode cell 12 or the negative electrode cell 13 electrolyte solution of opposite polarity can be circulated.
  • the negative electrode electrolyte can be circulated through the positive electrode cell 12 .
  • the SOC of the electrolyte in the battery cell 10 can be brought to a specific state, and the side reaction product generated in the positive electrode cell 12 can be redissolved.
  • Embodiment 1-2 a second arrangement mode will be described with reference to FIGS. 4 and 5.
  • FIG. both the second positive electrode circuit 32 and the second negative electrode circuit 42 are provided.
  • a main outbound pipe 33 a and a common outbound pipe 39 a are provided as pipes for supplying the positive electrode electrolyte from the positive electrode tank 22 to the positive electrode cell 12 .
  • the main outbound pipe 33 a is connected to the positive electrode tank 22 .
  • a pump (not shown) is provided in the main outbound pipe 33a.
  • Common outbound pipe 39 a is connected to main outbound pipe 33 a and positive electrode cell 12 .
  • the positive electrode electrolyte flows through the common outward pipe 39a, and the negative electrode electrolyte may flow through the switching of the three-way valve 390a, which will be described later.
  • a main return pipe 35 a and a common return pipe 39 c are provided as pipes for returning the positive electrode electrolyte from the positive electrode cell 12 to the positive electrode tank 22 .
  • the main return pipe 35 a is connected to the positive electrode tank 22 .
  • the common return pipe 39 c is connected to the main return pipe 35 a and the positive electrode cell 12 .
  • the positive electrode electrolyte flows through the common return pipe 39c during normal operation, and the negative electrode electrolyte may flow through the switching of the three-way valve 390c, which will be described later.
  • a main outbound pipe 33 b and a common outbound pipe 39 b are provided as pipes for supplying the positive electrode electrolyte from the positive electrode tank 22 to the negative electrode cell 13 .
  • the main outbound pipe 33 b is connected to the positive electrode tank 22 .
  • a pump (not shown) is provided in the main outbound pipe 33b.
  • the common outbound pipe 39 b is connected to the main outbound pipe 33 b and the negative electrode cell 13 .
  • the negative electrode electrolyte flows through the common outward pipe 39b, and the positive electrode electrolyte may flow through the switching of the three-way valve 390b, which will be described later.
  • a main return pipe 35 b and a common return pipe 39 d are provided as pipes for returning the positive electrode electrolyte from the negative electrode cell 13 to the positive electrode tank 22 .
  • the main return pipe 35 b is connected to the positive electrode tank 22 .
  • the common return pipe 39 d is connected to the main return pipe 35 b and the negative electrode cell 13 .
  • a negative electrode electrolyte flows through the common return pipe 39d during normal operation, and a positive electrode electrolyte may flow through the common return pipe 39d by switching a three-way valve 390d, which will be described later.
  • a main outbound pipe 43 b and a common outbound pipe 39 b are provided as pipes for supplying the negative electrode electrolyte from the negative electrode tank 23 to the negative electrode cell 13 .
  • the main outbound pipe 33 b is connected to the negative electrode tank 23 .
  • a pump (not shown) is provided in the main outbound pipe 33b.
  • the common outbound pipe 39 b is connected to the main outbound pipe 43 b and the negative electrode cell 13 .
  • a main return line 45b and a common return line 39d are provided as piping for returning the negative electrode electrolyte from the negative electrode cell 13 to the negative electrode tank 23 .
  • the main return pipe 45 b is connected to the negative electrode tank 23 .
  • the common return pipe 39 d is connected to the main return pipe 45 b and the negative electrode cell 13 .
  • a main outbound pipe 43 a and a common outbound pipe 39 a are provided as pipes for supplying the negative electrode electrolyte from the negative electrode tank 23 to the positive electrode cell 12 .
  • the main outbound pipe 43 a is connected to the negative electrode tank 23 .
  • a pump (not shown) is provided in the main outbound pipe 43a.
  • the common outbound pipe 39 a is connected to the main outbound pipe 43 a and the positive electrode cell 12 .
  • a main return pipe 45 a and a common return pipe 39 c are provided as pipes for returning the negative electrode electrolyte from the positive electrode cell 12 to the negative electrode tank 23 .
  • the main return pipe 45 a is connected to the negative electrode tank 23 .
  • the common return pipe 39 c is connected to the main return pipe 45 a and the positive electrode cell 12 .
  • a three-way valve 390a is provided at a connection point between the common outward pipe 39a, the main outward pipe 33a, and the main outward pipe 43a. By switching the three-way valve 390a, it is possible to switch whether the positive electrode electrolyte flows from the main outward pipe 33a to the common outward pipe 39a or the negative electrode electrolyte flows from the main outward pipe 43a to the common outward pipe 39a.
  • a three-way valve 390b is provided at a connection point between the common outward pipe 39b, the main outward pipe 33b, and the main outward pipe 43b.
  • a three-way valve 390c is provided at a connection point between the common return pipe 39c, the main return pipe 35a, and the main return pipe 45a.
  • a three-way valve 390d is provided at a connection point between the common return pipe 39d, the main return pipe 35b, and the main return pipe 45b. By switching the three-way valve 390d, depending on the polarity of the electrolyte discharged from the negative electrode cell 13, the positive electrode electrolyte flows from the common return pipe 39d to the main return pipe 35b, or from the common return pipe 39d to the main return pipe 45b. It is possible to switch whether the electrolytic solution flows.
  • the three-way valve 390a connects the main outward piping 33a and the common outward piping 39a, and blocks the main outward piping 43a and the common outward piping 39a.
  • the three-way valve 390c connects the main return pipe 35a and the common return pipe 39c, and blocks the main return pipe 45a and the common return pipe 39c.
  • the positive electrode electrolyte is supplied from the positive electrode tank 22 to the positive electrode cell 12 through the main outward pipe 33a and the common outward pipe 39a, and from the positive electrode cell 12, the common return pipe 39c and the main return pipe 35a. is returned to the positive electrode tank 22 through .
  • the three-way valve 390b communicates the main outward piping 33b and the common outward piping 39b, and blocks the main outward piping 43b and the common outward piping 39b.
  • the three-way valve 390d communicates the main return pipe 35b and the common return pipe 39d, and shuts off the main return pipe 45b and the common return pipe 39d.
  • the positive electrode electrolyte is supplied from the positive electrode tank 22 to the negative electrode cell 13 through the main outbound pipe 33b and the common outbound pipe 39b, and from the negative electrode cell 13 through the common return pipe 39d and the main return pipe 35b. is returned to the positive electrode tank 22 through .
  • the three-way valve 390b communicates the main outward piping 43b and the common outward piping 39b, and blocks the main outward piping 33b and the common outward piping 39b.
  • the three-way valve 390d connects the main return pipe 45b and the common return pipe 39d, and shuts off the main return pipe 35b and the common return pipe 39d.
  • the negative electrode electrolyte is supplied from the negative electrode tank 23 to the negative electrode cell 13 through the main outbound pipe 43b and the common outbound pipe 39b, and from the negative electrode cell 13, the common return pipe 39d and the main return pipe 45b. is returned to the negative electrode tank 23 through .
  • the three-way valve 390a communicates the main outward piping 43a and the common outward piping 39a, and blocks the main outward piping 33a and the common outward piping 39a.
  • the three-way valve 390c connects the main return pipe 45a and the common return pipe 39c, and blocks the main return pipe 35a and the common return pipe 39c.
  • the negative electrode electrolyte is supplied from the negative electrode tank 23 to the positive electrode cell 12 through the main outbound pipe 43a and the common outbound pipe 39a, and from the positive electrode cell 12, the common return pipe 39c and the main return pipe 45a. is returned to the negative electrode tank 23 through .
  • the three-way valves 390a and 390c are the first switching parts.
  • Three-way valves 390b and 390d are second switching units.
  • the second controller 92 circulates the positive electrode electrolyte in the positive electrode cell 12 and circulates the negative electrode electrolyte in the negative electrode cell 13. control the operation of the During normal operation of the RF battery system 1, the second controller 92 causes the three-way valve 390a to connect the main outbound pipe 33a and the common outward pipe 39a, and the three-way valve 390c to connect the common return pipe 39c and the main return pipe 35a. It will be in a state of communication.
  • the second controller 92 causes the three-way valve 390b to communicate the main outward pipe 43b and the common outward pipe 39b, and the three-way valve 390d to communicate the common return pipe 39d and the main return pipe 45b. are in communication with each other.
  • a negative electrode electrolyte is circulated.
  • the white arrows shown in FIG. 4 indicate the flow of the electrolytic solution.
  • Thick-line pipes 33a, 39a, 39c, and 35a shown in FIG. 4 are pipes through which the positive electrode electrolyte flows.
  • Thick-line pipes 43b, 39b, 39d, and 45b shown in FIG. 4 are pipes through which the negative electrode electrolyte flows.
  • the second controller 92 circulates the electrolyte of opposite polarity to the positive electrode cell 12 and the negative electrode cell 13 in which the side reaction product is generated. It controls the operation of the switching unit or the second switching unit. For example, when a by-reactant is generated in the positive electrode cell 12 , the second controller 92 controls the operation of the first switching section so that the negative electrode electrolyte is circulated through the positive electrode cell 12 .
  • the second controller 92 operates the three-way valve 390a as a first switching unit for switching between the first positive electrode circulation path 31 and the second negative electrode circulation path 42 so that the main outward piping 43a and the common outward piping 39a communicate with each other.
  • the three-way valve 390c is switched so that the common return pipe 39c and the main return pipe 45a are communicated with each other.
  • the negative electrode electrolyte is circulated in the White arrows shown in FIG. 5 indicate the flow of the electrolytic solution.
  • Thick-line pipes 43a, 43b, 39a, 39b, 39c, 39d, 45a, and 45b shown in FIG. 5 are pipes through which the negative electrode electrolyte flows.
  • the second controller 92 controls the operation of the second switching unit so that the positive electrode electrolyte is circulated through the negative electrode cell 13.
  • the second controller 92 serves as a second switching unit for switching between the first negative electrode circulation path 41 and the second positive electrode circulation path 32, and is a three-way switch so that the main outward piping 33b and the common outward piping 39b communicate with each other.
  • the three-way valve 390d is switched so that the common return pipe 39d and the main return pipe 35b are communicated.
  • the positive electrode cell 12 or the negative electrode cell 13 can be circulated with electrolyte solutions of opposite polarities.
  • Embodiment 2 the above-described second form will be described with reference to FIG.
  • the side reactants are redissolved by performing a short-time discharge.
  • the battery cell 10 is provided with the variable resistance section 71 .
  • the controller 9 comprises a third controller 93 .
  • the variable resistance section 71 is provided between the positive electrode cell 12 and the negative electrode cell 13 that constitute the battery cell 10 .
  • a switch (not shown) is provided between the battery cell 10 and the variable resistance section 71 . By switching this switch, the battery cell 10 discharges to the variable resistance section 71 . Discharge may be started and stopped simply by changing the resistance value of the variable resistance section 71 without using a switch. The electric power supplied to the variable resistance section 71 by the discharge is consumed by resistance heating. By discharging from the battery cell 10 to the variable resistance section 71, the SOC of the battery cell 10 is lowered. The SOC of the battery cell 10 changes according to the resistance value of the variable resistance section 71 .
  • the third controller 93 performs discharge so that the difference between the SOC on the inlet side of the electrolyte supplied to the battery cell 10 and the SOC on the outlet side of the electrolyte discharged from the battery cell 10 is 10% or more. to control the power conversion device 8.
  • the difference is 10% or more, the SOC of the electrolyte in the battery cell 10 is in a specific state.
  • the larger the difference the easier it is for the SOC of the electrolyte in the battery cell 10 to reach the specific state.
  • said difference may also be 16% or more, 20% or more, 24% or more, in particular 30% or more.
  • the above difference is 100% or less, further 90% or less, 80% or less, especially 75% or less, 70% or less.
  • the third controller 93 controls the power conversion device 8 so as to discharge in a short period of time, for example, 10 minutes or less, so that the difference becomes 10% or more.
  • the current density and the flow rate of the electrolytic solution can be appropriately selected so that the side reaction product in the battery cell 10 can be redissolved in a short period of time.
  • the current density is, for example, 300 mA/cm 2 or higher, 400 mA/cm 2 or higher, 500 mA/cm 2 or higher, particularly 600 mA/cm 2 or higher.
  • the flow rate of the electrolytic solution is, for example, 4.0 cc/min/cm 2 or less, 3.0 cc/min/cm 2 or less, 2.0 cc/min/cm 2 or less, particularly 0.0 cc/min/cm 2 or less.
  • the flow rate of the electrolytic solution is the amount of electrolytic solution that flows into the battery cell 10 .
  • the unit of the flow rate of the electrolytic solution is "cc/min/cm 2 ", which indicates the volume of the electrolytic solution that flows per 1 cm 2 of the electrode in the battery cell 10 for 1 minute.
  • the fact that the flow rate of the electrolytic solution is 0.0 cc/min/cm 2 means that the electrolytic solution does not flow in the battery cell 10 and that the electrolytic solution is not circulated. Matters relating to the flow rate of the electrolyte also apply to charging, which will be described later.
  • the flow rate of the electrolytic solution is set to 2.0 cc/min/cm 2 or less, and the variable resistance section 71 is set to a high resistance value to discharge from the battery cell 10 to the variable resistance section 71 .
  • the SOC of the electrolyte discharged from the battery cell 10 on the outlet side becomes low.
  • the RF battery system 1 is provided with a flow meter (not shown).
  • the flowmeters are provided, for example, in the outward piping 24 through which the positive electrode electrolyte flows and the outward piping 25 through which the negative electrode electrolyte flows.
  • the flowmeters are provided downstream of the pump 28 ( FIG. 1 ) in the outward piping 24 and downstream of the pump 29 ( FIG. 1 ) in the outward piping 25 .
  • the flow rate of the electrolytic solution can be adjusted by controlling the outputs of the pumps 28 and 29 with the pump controller.
  • the third controller 93 controls the power converter 8 based on the results measured by the flowmeter.
  • the flow rate of the electrolytic solution can also be calculated from the open circuit voltage (OCV) of the monitor cell 61, the temperature of the electrolytic solution, and the outputs of the pumps 28 and 29, for example.
  • OCV open circuit voltage
  • a thermometer for measuring the temperature of the electrolytic solution is provided, for example, at the same position as the flowmeter described above.
  • the third controller 93 sets the variable resistance section 71 to a low resistance value. Therefore, during normal operation of the RF battery system 1, the SOC of the battery cells 10 is controlled within a range expanded from the range of utilization of the main SOC.
  • the third controller 93 sets the variable resistance section 71 to a high resistance value.
  • the resistance value of the variable resistance section 71 is set to a value that makes the difference 10% or more.
  • the controller 9 issues a command to the power conversion device 8 through the first controller 91 so that the SOC of the battery cell 10 is held in a specific state for 10 seconds or more. Specifically, a command is issued to charge or discharge the battery cell 10 for 10 seconds or more in a state where the resistance value is set so as to cause resistance heating in the variable resistance portion 71 .
  • the battery cell 10 is discharged according to the resistance value of the variable resistance section 71 . Due to this discharge, the difference between the SOC on the inlet side and the SOC on the outlet side of the battery cell 10 becomes 10% or more.
  • the SOC of the battery cell 10 is lowered by the third controller 93, so that the SOC of the electrolyte in the battery cell 10 can be brought to a specific state. As a result, the side reactants generated in the battery cells 10 can be redissolved.
  • the RF battery system 1 of Embodiment 2 can set the SOC of the electrolyte in the battery cell 10 to a specific state by arranging the variable resistance unit 71 in the battery cell 10 and controlling the resistance value of the variable resistance unit 71. .
  • the RF battery system 1 of Embodiment 2 can be used by simply modifying equipment used in normal operation of the RF battery system 1 to set the SOC of the electrolyte in the battery cell 10 to a specific state. can. Therefore, in the RF battery system 1 of the second embodiment, compared to the RF battery system 1 of the first embodiment, it is easier to simplify the configuration of the bank 2 .
  • Embodiment 3 describes the above-described third embodiment with reference to FIG. 7 .
  • charging for a short period of time causes the side reactants to be redissolved.
  • a second power supply 72 is connected to the power conversion device 8 .
  • controller 9 comprises a third controller 93 .
  • the second power supply 72 is a power supply different from the power supply 810 (Fig. 1) connected to the power system.
  • Various power storage means such as a secondary battery can be used for the second power supply 72 .
  • the second power supply 72 charges the bank 2 via the power conversion device 8 . This charging changes the SOC of the battery cell 10 .
  • the third controller 93 performs charging so that the difference between the SOC on the inlet side of the electrolyte supplied to the battery cell 10 and the SOC on the outlet side of the electrolyte discharged from the battery cell 10 is 10% or more. to control the power conversion device 8.
  • the difference is 10% or more, the SOC of the electrolyte in the battery cell 10 is in a specific state.
  • the larger the difference the easier it is for the SOC of the electrolyte in the battery cell 10 to reach the specific state.
  • said difference may also be 16% or more, 20% or more, 24% or more, in particular 30% or more.
  • the above difference is 100% or less, further 90% or less, 80% or less, especially 75% or less, 70% or less.
  • the third controller 93 controls the power conversion device 8 so as to perform charging in a short period of time, for example, 10 minutes or less, so that the difference becomes 10% or more.
  • the current density and the flow rate of the electrolytic solution can be appropriately selected so that the side reaction product in the battery cell 10 can be redissolved in a short period of time.
  • the current density is, for example, 300 mA/cm 2 or higher, 400 mA/cm 2 or higher, 500 mA/cm 2 or higher, especially 600 mA/cm 2 or higher.
  • the flow rate of the electrolytic solution is, for example, 4.0 cc/min/cm 2 or less, 3.0 cc/min/cm 2 or less, 2.0 cc/min/cm 2 or less, particularly 0.0 cc/min/cm 2 or less.
  • the electrolyte flow rate is 0.0 cc/min/cm 2 , the electrolyte does not circulate.
  • the flow rate of the electrolytic solution is set to 2.0 cc/min/cm 2 or less, the current density is set to 600 mA/cm 2 or more, and the second power supply 72 is connected to the bank 2 via the power conversion device 8. charging time.
  • the SOC at the outlet side of the electrolyte discharged from the battery cell 10 increases.
  • the third controller 93 controls so as not to charge the bank 2 from the second power supply 72 . Therefore, during normal operation of the RF battery system 1, the SOC of the battery cells 10 is controlled within a range expanded from the range of utilization of the main SOC.
  • the SOC of the battery cell 10 is increased by the third controller 93, so that the SOC of the electrolyte in the battery cell 10 can be brought to a specific state. As a result, the side reactants generated in the battery cells 10 can be redissolved.
  • the RF battery system 1 of Embodiment 3 connects the second power supply 72 to the power conversion device 8, and controls the charging of the bank 2 from the second power supply 72, thereby specifying the SOC of the electrolyte in the battery cell 10. state.
  • the RF battery system 1 of Embodiment 3 can be used by simply modifying equipment used in normal operation of the RF battery system 1 to set the SOC of the electrolyte in the battery cell 10 to a specific state. can.
  • the RF battery system 1 has at least one of the configuration of the first embodiment, the configuration of the second embodiment, and the configuration of the third embodiment.
  • the RF battery system 1 may have all of the configuration of the first embodiment, the configuration of the second embodiment, and the configuration of the third embodiment.
  • Embodiment 4 describes an RF battery system 1 including a plurality of banks 2 with reference to FIG. 8 .
  • the plurality of banks 2 includes a first bank 2a used for normal operation and a second bank 2b used for electrolyte recovery work.
  • the controller 9 comprises a rotation controller 94 .
  • the first bank 2a is a bank that performs charging and discharging between an external power source 810 and a load 820 (Fig. 1).
  • the SOC of the battery cells 10 in the first bank 2a is controlled within an expanded range of the main SOC.
  • the SOC of the electrolyte in the battery cell 10 is substantially the same as the SOC of the cathode electrolyte in the cathode tank 22, and substantially the same as the SOC of the anode electrolyte in the anode tank 23. is the same as
  • the number of first banks 2a is, for example, 2 or more, further 10 or more, particularly 15 or more. The larger the number of first banks 2a, the easier it is for the battery capacity of the entire RF battery system 1 to be secured.
  • the second bank 2b is a bank for recovering the electrolyte.
  • the SOC of the battery cells 10 in the second bank 2b is controlled by the first controller 91 to a specific state. That is, the SOC of the battery cell 10 in the second bank 2b is a state in which the SOC of the electrolyte in the battery cell 10 differs from the SOC of the positive electrode electrolyte in the positive electrode tank 22 by 5% or more, and is held for 10 seconds or more in at least one state in which the SOC of the negative electrode electrolyte in the negative electrode tank 23 differs by 5% or more from the SOC of the negative electrode electrolyte.
  • the number of second banks 2b is less than the number of first banks 2a. For example, the ratio of the number of the second banks 2b to the total number of the plurality of banks 2 is 30% or less, further 20% or less, particularly 10% or less.
  • the number of all banks 2 is, for example, 4 or more. As the number of banks 2 increases, the battery capacity of the entire RF battery system 1 can be increased.
  • the number of banks 2 may be 11 or more, or 16 or more. If the number of banks 2 is large, the entire system becomes huge, and management of the banks 2 becomes complicated.
  • the upper limit of the number of banks 2 is, for example, 100 or less, and further 50 or less.
  • the number of banks 2 is, for example, 11 or more and 100 or less, or 16 or more and 50 or less.
  • the controller 9 controls charging and discharging of each bank 2 independently. Therefore, it is possible to recover the electrolyte in the second bank 2b while charging or discharging the first bank 2a.
  • the controller 9 issues a charging or discharging command to the power conversion device 8 of each first bank 2a.
  • the battery cells 10 are charged or discharged according to the requested charge amount or discharge amount.
  • the controller 9 issues an electrolyte recovery operation command to the power conversion device 8 of the second bank 2b.
  • the battery cells 10 are not charged or discharged between the power source 810 and the load 820 (FIG. 1), and the recovery work of the electrolyte is performed.
  • the SOC of the battery cell 10 is set to a specific state using the means of the first to third embodiments described above.
  • some cells of the cell stack 200 constitute the monitor cell 60, and the circulation paths, valves, and other monitor cells described in the first to third embodiments are omitted.
  • the controller 9 of this example includes a rotation controller 94 .
  • the rotation controller 94 controls the power conversion device 8 so that the states of the battery cells 10 of the plurality of banks 2 are in a specific state in order. In other words, for each of the plurality of banks 2, the rotatable controller 94 selects a time zone for the first bank 2a during normal operation and a time zone for the second bank 2b during the recovery work of the electrolyte. Control the power conversion device 8 to include.
  • the rotation controller 94 for example, when the total number of the plurality of banks 2 is 11, the following control is performed. Let each bank 2 be No. 1, No. 2...No. 11. At a certain time, among the plurality of banks 2, No. 1 to No.
  • the third controller 93 can perform the following controls.
  • the first control when performing the above-described short-time discharge to recover the electrolyte, the third controller 93 charges the first bank 2a with the discharge power of the second bank 2b. may be controlled. In this case, the SOC of the electrolyte in the battery cells 10 of the second bank 2b can be set to a specific state without using the variable resistance section 71 used in the second embodiment.
  • the second control when performing the above-described short-time charging to recover the electrolyte, the third controller 93 charges the second bank 2b with the discharged power of the first bank 2a. may be controlled. In this case, the SOC of the electrolyte in the battery cells 10 of the second bank 2b can be brought to a specific state without using the second power supply 72 used in the third embodiment.
  • the rotation controller 94 allows the second bank 2b to The recovery operation of the electrolyte can be performed with the SOC of the electrolyte in the battery cell 10 set to a specific state. That is, according to the RF battery system 1 of Embodiment 4, the recovery work of the electrolytic solution can be performed without stopping the normal operation of the RF battery system 1 .
  • Test Example 1 In Test Example 1, in a bank in which a side reaction product was generated in a positive electrode cell in a high SOC region, the improvement of the battery performance of the bank was examined by performing an electrolyte recovery operation for redissolving the side reaction product. In this example, an RF battery system with multiple battery cells was tested.
  • Specimen 1-1 is a bank in which a side reaction product is generated in the positive electrode cell in the high SOC region. In the specimen 1-1, the recovery work of the electrolytic solution for redissolving the by-reactants was not performed.
  • ⁇ Test body 1-2> the negative electrode electrolyte is circulated to the positive electrode cell for the bank in which the by-reactant is generated in the positive electrode cell in the high SOC region, and the electrolyte is recovered by re-dissolving the by-reactant. did the work.
  • the circulation of the negative electrode electrolyte to the positive electrode cell is performed by controlling the operation of the first switching unit by the second controller to switch the first positive electrode circulation path and the second negative electrode circulation. (see also Figures 2 and 3). The circulation of the negative electrode electrolyte to the positive electrode cell was performed for 30 seconds.
  • the state of charge of the electrolyte in the battery cell after circulating the reverse polarity electrolyte for 30 seconds was 158% different from the state of charge of the positive electrode electrolyte in the positive electrode tank. That is, in the test sample 1-2, the specific state in which the state of charge of the electrolyte in the battery cell differs from the state of charge of the positive electrode electrolyte in the positive electrode tank by 5% or more was maintained for 10 seconds or longer. The state of charge of the positive electrode electrolyte in the positive electrode tank was 79%.
  • the difference between the state of charge of the electrolyte in the battery cell and the state of charge of the positive electrode electrolyte in the positive electrode tank is the negative electrode electrolyte viewed from the state of charge of the positive electrode electrolyte. It is obtained from the state of charge.
  • test sample 1-3 discharge was performed to the bank in which the side reaction product was generated in the positive electrode cell in the high SOC region, and the recovery work of the electrolytic solution was performed by redissolving the side reaction product.
  • test sample 1-3 as described in Embodiment 4, a plurality of banks were provided, and the banks used for normal operation were charged with the discharge power of the banks in which the recovery work of the electrolyte was performed by the third controller. .
  • the discharge conditions were as follows.
  • the flow rate of the electrolyte circulating in the battery cells is 1.6 cc/min/cm 2 .
  • the current density of the battery cell is 670 mA/cm 2 .
  • the discharge time is 30 seconds.
  • the difference between the state of charge on the inlet side of the electrolyte supplied to the battery cell and the state of charge on the outlet side of the electrolyte discharged from the battery cell is 20%.
  • the state of charge of the electrolyte in the battery cell was 10% different from the state of charge of the positive electrode electrolyte in the positive electrode tank. That is, in the test sample 1-3, the specific state in which the state of charge of the electrolyte in the battery cell differs from the state of charge of the positive electrode electrolyte in the positive electrode tank by 5% or more was maintained for 10 seconds or longer.
  • the state of charge of the positive electrode electrolyte in the positive electrode tank was 79%.
  • the state of charge of the electrolyte in the battery cell is the average value of the state of charge of the electrolyte in the battery cell.
  • ⁇ SOC of battery cell> The bank of each test body was charged, and the SOC of the battery cell was measured when the battery cell was charged to a preset voltage.
  • the charging conditions were as follows.
  • the flow rate of the electrolyte circulating in the battery cells is 1.6 cc/min/cm 2 .
  • the current density of the battery cell is 256 mA/cm 2 .
  • Table 1 shows the results.
  • the SOC of the battery cell when the battery cell is charged to the preset voltage is referred to as "end of charge SOC”.
  • test specimens 1-2 and 1-3 subjected to the recovery work of the electrolyte have a higher battery cell capacity than the test specimen 1-1 which has not been subjected to the recovery work of the electrolyte. It was found that the SOC was improved.
  • Test Specimen 1-2 which was subjected to the electrolyte recovery work of circulating the reverse polarity electrolyte in the positive electrode cell in which the side reaction product was generated, had a battery cell SOC lower than that of Test Specimen 1-1. An improvement of about 10% was found.
  • Test Example 2 In Test Example 2, the discharge time was changed in order to recover the electrolytic solution by discharging the bank in which the side reaction product was generated in the positive electrode cell in the high SOC region and redissolving the side reaction product. . That is, in Test Example 2, the time for which the state of charge of the battery cell is maintained in the specific state was changed.
  • Specimen 2-1 is a bank in which a side reaction product is generated in the positive electrode cell in the high SOC region. The specimen 2-1 was not subjected to the recovery work of the electrolytic solution for redissolving the by-reactants.
  • Test body 2-2, test body 2-3, test body 2-4> In the test specimens 2-2, 2-3, and 2-4, the bank in which the side reaction is generated in the positive electrode cell in the high SOC region is discharged to redissolve the side reaction.
  • the recovery work of the electrolyte was carried out.
  • Each test sample was provided with a plurality of banks as described in the fourth embodiment, and the banks used for normal operation were charged with the discharge power of the banks in which the recovery work of the electrolytic solution was performed by the third controller.
  • the discharge conditions for each specimen were the same except for the discharge time.
  • the flow rate of electrolyte circulating in the battery cells is 0.96 cc/min/cm 2 .
  • the current density of the battery cell is 670 mA/cm 2 .
  • the difference between the state of charge at the inlet side of the electrolyte supplied to the battery cell and the state of charge at the outlet side of the electrolyte discharged from the battery cell is 33%.
  • the discharge time for each specimen was as follows. Specimen 2-2 is 30 seconds. Specimen 2-3 is 60 seconds. Specimens 2-4 are 120 seconds.
  • the state of charge of the electrolyte in the battery cell was different from the state of charge of the positive electrode electrolyte in the positive electrode tank by 16.5%. That is, in the test specimens 2-2, 2-3, and 2-4, the state of charge of the electrolyte in the battery cell is different from the state of charge of the positive electrode electrolyte in the positive electrode tank by 5% or more. was held. In both specimens, the state of charge of the positive electrode electrolyte in the positive electrode tank was 68%.
  • ⁇ SOC of battery cell> The bank of each test body was charged, and the SOC of the battery cell was measured when the battery cell was charged to a preset voltage.
  • the charging conditions were as follows.
  • the flow rate of electrolyte circulating in the battery cells is 0.96 cc/min/cm 2 .
  • the current density of the battery cell is 256 mA/cm 2 .
  • Table 2 shows the results.
  • the SOC of the battery cell when the battery cell is charged to the preset voltage is referred to as "end of charge SOC”.
  • the SOC of the battery cell can be further improved by lengthening the discharge time, that is, by lengthening the time during which the state of charge of the battery cell is held in a specific state.
  • the SOC of the battery cell can be further improved by increasing the discharge time to 30 seconds or longer. It was found that when the discharge time exceeded 60 seconds, the rate of improvement in the SOC of the battery cell was very small. Therefore, even if the discharge time is as short as 10 minutes or less, it can be expected that the side reaction products generated in the battery cells can be redissolved.
  • Test Example 3 In Test Example 3, the difference in SOC was changed in performing the recovery work of the electrolytic solution for redissolving the side reaction by discharging the bank in which the side reaction was generated in the positive electrode cell in the high SOC region. rice field.
  • the difference in SOC is the difference between the state of charge on the inlet side of the electrolyte supplied to the battery cell and the state of charge on the outlet side of the electrolyte discharged from the battery cell. That is, in Test Example 3, the state of charge of the battery cells was changed within the range of the specific state.
  • Specimen 3-1 is a bank in which a side reaction product is generated in the positive electrode cell in the high SOC region. In the specimen 3-1, the recovery work of the electrolytic solution for redissolving the by-reactants was not performed.
  • test body 3-2, test body 3-3, test body 3-4 In test specimens 3-2, 3-3, and 3-4, discharge is performed on the bank in which the side reaction product is generated in the positive electrode cell in the high SOC region, and the side reaction product is redissolved. The recovery work of the electrolyte was carried out. Each test sample was provided with a plurality of banks as described in the fourth embodiment, and the banks used for normal operation were charged with the discharge power of the banks in which the recovery work of the electrolytic solution was performed by the third controller. Table 3 shows the discharge conditions for each specimen. The discharge time was set to 30 seconds for all specimens.
  • the state of charge of the electrolyte in the battery cells was maintained within the specific state range for 10 seconds or longer.
  • the state of charge of the positive electrode electrolyte in the positive electrode tank was 68%.
  • ⁇ SOC of battery cell The bank of each test body was charged, and the SOC of the battery cell was measured when the battery cell was charged to a preset voltage.
  • the charging conditions were as follows.
  • the flow rate of electrolyte circulating in the battery cells is 0.96 cc/min/cm 2 .
  • the current density of the battery cell is 256 mA/cm 2 .
  • Table 3 shows the results.
  • the SOC of the battery cell when the battery cell is charged to the preset voltage is referred to as "end of charge SOC”.
  • the SOC of the battery cells can be further improved by increasing the difference in SOC.
  • the SOC of the battery cells can be further improved when the SOC difference is 30% or more, 33% or more, and further 45% or more. It was found that when the difference in SOC exceeds 48%, the rate of improvement in the SOC of the battery cell becomes very small. Therefore, it can be expected that by discharging so that the difference in SOC is 10% or more and 50% or less, it is possible to re-dissolve the side reaction product generated in the battery cell.
  • Redox flow battery system (RF battery system) 2 bank 2a first bank 2b second bank 10 battery cell 11 diaphragm 12 positive electrode cell 13 negative electrode cell 14 positive electrode 15 negative electrode 22 positive electrode tank 23 negative electrode tank 24, 25 outbound pipe 26, 27 return route Piping 28, 29 Pump 31 First positive electrode circulation path 32 Second positive electrode circulation path 33, 33a, 33b Main outward piping 34a, 34b Branch outward piping 35, 35a, 35b Main return piping 36a, 36b Branch return piping 37a, 37b, 38a, 38b valves 39a, 39b common outward piping, 39c, 39d common return piping 390a, 390b three-way valve, 390c, 390d three-way valve 41 first negative electrode circulation path 42 second negative electrode circulation path 43, 43a , 43b main outbound pipe 44a, 44b branch outbound pipe 45, 45a, 45b main return pipe 46a, 46b branch return pipe 47a, 47b, 48a, 48b valve 60, 61 monitor cell 71 variable resistor 72 second power supply 8

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Abstract

L'invention concerne un système de batterie à flux redox comprenant une banque, et un dispositif de commande qui commande l'état de charge de la banque. La batterie comporte un élément de batterie, un réservoir d'électrode positive dans lequel est stocké un anolyte qui circule dans l'élément de batterie, un réservoir d'électrode négative dans lequel est stocké un catholyte qui circule dans l'élément de batterie, et un dispositif de conversion de puissance qui commande la charge et la décharge de l'élément de batterie. Le dispositif de commande comporte un premier dispositif de commande qui commande le dispositif de conversion de puissance de façon à maintenir l'état de charge de l'élément de batterie dans un état spécifique pendant au moins dix secondes. L'état spécifique est au moins l'un d'un premier état et d'un second état, le premier état étant un état dans lequel l'état de charge de l'électrolyte à l'intérieur de l'élément de batterie diffère de l'état de charge de l'anolyte à l'intérieur du réservoir d'électrode positive d'au moins 5 %, et le second état étant un état dans lequel l'état de charge de l'électrolyte dans l'élément de batterie diffère de l'état de charge du catholyte à l'intérieur du réservoir d'électrode négative d'au moins 5 %.
PCT/JP2022/015672 2021-06-21 2022-03-29 Système de batterie à flux redox WO2022270108A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006040648A (ja) * 2004-07-23 2006-02-09 Kansai Electric Power Co Inc:The レドックスフロー電池システムの運転方法
JP2006147375A (ja) * 2004-11-19 2006-06-08 Kansai Electric Power Co Inc:The レドックスフロー電池およびその運転方法
JP2016119258A (ja) * 2014-12-22 2016-06-30 住友電気工業株式会社 レドックスフロー電池の運転方法、及びレドックスフロー電池システム

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006040648A (ja) * 2004-07-23 2006-02-09 Kansai Electric Power Co Inc:The レドックスフロー電池システムの運転方法
JP2006147375A (ja) * 2004-11-19 2006-06-08 Kansai Electric Power Co Inc:The レドックスフロー電池およびその運転方法
JP2016119258A (ja) * 2014-12-22 2016-06-30 住友電気工業株式会社 レドックスフロー電池の運転方法、及びレドックスフロー電池システム

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