JP2012164530A - Electrolyte circulation type battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolyte circulation type battery that prevents self-discharge.SOLUTION: A redox-flow battery 1 as an example of an electrolyte circulation type battery includes: a battery cell 10; electrolyte tanks 20 in which respective electrolytes are stored; circulation routes 30 that allow the respective electrolytes to circulate between the respective electrolyte tanks 20 and the battery cell 10; and circulation pumps 40 that allow the respective electrolytes to circulate through the respective circulation routes 30. The circulation routes 30 have: respective outward lines 31 that send the respective electrolytes from the respective electrolyte tanks 20 to the battery cell 10; and respective return lines 32 that return the respective electrolytes from the battery cell 10 to the respective electrolyte tanks 20. The redox-flow battery 1 also includes: collection spaces 50 that are positioned at a lower level than the battery cell 10 and collect the respective electrolytes inside the battery cell 10; collection passages 51 that communicate the battery cell 10 with the respective collection spaces 50; first opening/closing means 55 that open and close the respective collection passages 51; and second opening/closing means 56 that open and close the respective outward lines 31.

Description

  The present invention relates to an electrolyte flow type battery capable of suppressing self-discharge.

  In recent years, the introduction of wind power generation and solar power generation using renewable energy such as wind power and sunlight has been promoted worldwide as a countermeasure against global warming. Since these power generation outputs are affected by the weather, there is a problem in the operation of the power system that it becomes difficult to maintain the frequency and voltage when a large amount of introduction proceeds. As one of countermeasures against this problem, it has been proposed to install a large capacity storage battery to smooth output fluctuation, store surplus power, and level load.

  One type of large-capacity storage battery is an electrolyte flow type battery such as a redox flow battery. A redox flow battery performs charge / discharge by supplying a positive electrode electrolyte and a negative electrode electrolyte to battery cells in which a diaphragm is interposed between a positive electrode and a negative electrode. As the electrolytic solution, an aqueous solution containing metal ions whose valence changes by oxidation and reduction is generally used. Redox flow batteries include, for example, iron-chromium redox flow batteries using an aqueous iron ion solution for the positive electrode electrolyte and an aqueous chromium ion solution for the negative electrode electrolyte, and a vanadium system using an aqueous vanadium ion solution for the positive and negative electrode electrolytes. Redox flow batteries are well known (see, for example, Patent Document 1).

  FIG. 9 is a schematic view for explaining a conventional electrolyte flow type battery (redox flow battery). The redox flow battery 4 includes a battery cell 10. The battery cell 10 is divided into a positive electrode cell 102 and a negative electrode cell 103 by a diaphragm 101 that can transmit ions. The positive electrode cell 102 includes a positive electrode 104, and the negative electrode cell 103 includes a negative electrode 105. Yes. The redox flow battery 4 includes an electrolyte tank 20 that stores an electrolyte solution for the positive electrode and the negative electrode, respectively, and an electrolyte solution between the electrolyte tank 20 and the battery cell 10 (the positive electrode cell 102 and the negative electrode cell 103). A circulation path 30 for circulation in the circulation path 30 and a circulation pump 40 for circulating the electrolytic solution in the circulation path 30. The circulation path 30 includes an outward piping 31 for sending an electrolytic solution from the electrolytic solution tank 20 to the battery cell 10 (positive electrode cell 102, negative electrode cell 103), and an electrolytic solution from the battery cell 10 (positive electrode cell 102, negative electrode cell 103) to the electrolytic solution. And a return pipe 32 that returns to the tank 20.

  In the redox flow battery 4, the forward piping 31 is connected so as to communicate the lower part of the electrolyte tank 20 and the lower part of the battery cell 10, and the return path so as to communicate the upper part of the electrolyte tank 20 and the upper part of the battery cell 10. Pipe 32 is connected. Then, on each of the positive electrode side and the negative electrode side, the circulation pump 40 is activated, so that the electrolytic solution is sent from the electrolytic solution tank 20 to the battery cell 10 via the outward piping 31. The electrolytic solution supplied to the battery cell 10 is discharged upward from the lower side of the battery cell 10 through the inside thereof, and returned to the electrolytic solution tank 20 via the return pipe 32 and circulated. In the battery cell 10, a battery reaction (charge / discharge reaction) is performed. In addition, in the redox flow battery 4 shown in FIG. 9, the case where vanadium ion aqueous solution is used for the electrolyte solution of positive and negative electrodes is mentioned as an example. Moreover, the solid line arrow in a battery cell in FIG. 9 shows a charging reaction, and the broken line arrow shows a discharging reaction, respectively.

  A battery cell of a redox flow battery is generally used in a form called a cell stack in which a plurality of unit cells each having a positive electrode, a diaphragm, and a negative electrode are stacked. FIG. 10 is a schematic diagram for explaining the cell stack. The cell stack 200 has a structure in which a cell frame 202 having a bipolar plate 201, a positive electrode 104, a diaphragm 101, a negative electrode 105, and a cell frame 202 having a bipolar plate 201 are sequentially stacked. The cell stack 200 shown in FIG. 10 is configured by arranging a pair of end plates 210 on both sides and fastening both end plates 210 with fastening members 220 such as bolts.

JP 2006-147374 A

  It is desired to suppress self-discharge of an electrolyte flow type battery (redox flow battery).

For redox flow batteries, depending on the specifications (output / capacity), for example, in the case of 170 kW / 8 hours, the battery cells (cell stack), the electrolyte tanks for positive and negative electrodes, the circulation paths, and the circulations A basic configuration with the pump is one unit (basic unit), and a system is constructed by combining four units. That is, in the above-described redox flow battery (basic unit × 4 units), there are four battery cells and four positive and negative electrode electrolyte tanks (four positive electrode electrolyte tanks + four negative electrode electrolyte tanks, 8 units in total) In the case of the above specifications, in one basic unit redox flow battery, for example, the weight per battery cell is 1500 kg or more, and the amount of electrolyte stored per electrolyte tank is 20 m ³ (20000 Liter).

  On the other hand, as a redox flow battery layout, as illustrated in FIG. 9, it is conceivable that the battery cell 10 and the electrolyte solution tank 20 are arranged substantially horizontally. As described above, since the battery cell is heavy, it is not necessary to provide a solid base for supporting the battery cell by installing the battery cell on the ground or floor in the same manner as the electrolyte tank. Easy maintenance. In particular, when the battery cell is installed at a higher position with respect to the electrolyte tank, that is, when the pedestal is made higher, the pedestal is required to have robustness and strength so as to satisfy the seismic design. On the other hand, it is conceivable to embed an electrolyte tank, but since the electrolyte tank has a large volume as described above, the cost of burying the electrolyte tank is high. Therefore, it is considered that the merit of arranging the battery cell and the electrolytic solution tank side by side substantially horizontally is great.

  However, in the conventional redox flow battery, when the battery cell and the electrolyte tank are arranged substantially horizontally, when the circulation pump stops, the liquid level of the electrolyte in the battery cell and the electrolyte in the electrolyte tank The liquid level becomes equal, and the electrolytic solution remains in the battery cell (see FIG. 9). In addition, the circulation pump may be repeatedly started and stopped depending on the purpose of use (use) of the battery, in addition to being stopped during maintenance, for example. And when electrolyte solution remains in a battery cell, there exist the following problems.

(1) Self-discharge occurs in the battery cell, and the discharge capacity of the battery decreases accordingly.
(2) As the electrolyte solution generates heat due to self-discharge, the temperature of the members (diaphragm, electrode, etc.) constituting the battery cell rises, thereby promoting the deterioration of these members. In particular, in applications where the circulation pump is frequently started and stopped, the members are significantly deteriorated.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide an electrolyte flow type battery capable of suppressing self-discharge.

  The electrolyte flow type battery of the present invention includes a battery cell, an electrolyte tank that stores the electrolyte, an outward piping that sends the electrolyte from the electrolyte tank to the battery cell, and an electrolyte that returns from the battery cell to the electrolyte tank. A circulation path having a return pipe, and a circulation pump for circulating the electrolyte in the circulation path. And it is installed in a position lower than the battery cell, a recovery space part for recovering the electrolytic solution in the battery cell, a recovery passage communicating the battery cell and the recovery space part, and a first opening / closing means for opening and closing the recovery path And.

  According to this configuration, when the circulating pump is stopped, the electrolyte in the battery cell can be collected in the collection space through the collection passage by opening the collection passage through the first opening / closing means. Therefore, when the circulation pump is stopped, the electrolytic solution in the battery cell can be removed, and the amount of the electrolytic solution remaining in the battery cell can be reduced as compared with the conventional battery. On the other hand, when the battery is operated by starting the circulation pump and circulating the electrolyte in the circulation path, the recovery passage is closed via the first opening / closing means so that the electrolyte does not flow into the recovery space. To do. Therefore, self-discharge due to the electrolyte remaining in the battery cell can be suppressed, the discharge capacity is reduced due to the self-discharge, and the deterioration of the constituent members of the battery cell 10 caused by the heat generation of the electrolyte due to the self-discharge is prevented. Can be reduced. In particular, the effect is exhibited when the battery cell and the electrolytic solution tank are arranged substantially horizontally, or when the electrolytic solution tank is installed at a position higher than the battery cell. The recovery space is preferably provided for each of the positive electrode and the negative electrode. However, if the recovery space is provided only for either the positive electrode or the negative electrode, the same effect can be expected.

  Here, since the recovery space portion is installed at a position lower than the battery cell, the electrolyte solution in the battery cell can be naturally guided to the recovery space portion as it is if the recovery passage is opened. The collection space is a container (container) for collecting the electrolytic solution in the battery cell, and its size (volume) can be extremely small as compared with the electrolytic solution tank. Therefore, it is easy to install the recovery space below the battery cell. For example, the recovery space may be formed in a flat container shape, or may be formed by meandering a tube.

  As one form of the electrolyte flow type battery of the present invention, it is mentioned that the volume of the recovery space is equal to or greater than the amount of the electrolyte flowing in the battery cell.

  According to this configuration, by securing a volume in the recovery space that is equal to or greater than the amount of the electrolyte flowing in the battery cell, the electrolyte remaining in the battery cell is completely removed when the circulation pump is stopped. Can be pulled out. As a result, self-discharge can be more reliably suppressed. Here, in the case of the above specifications, the volume of the battery cell per battery cell is about 100 to 200 liters for both the positive electrode cell and the negative electrode cell, and the volume of the battery cell and the amount of the electrolyte flowing in the battery cell Are approximately equal. Therefore, the volume of the recovery space portion may be about 100 to 200 liters, for example, in accordance with the volume of each positive and negative cell. The volume of the recovery space may be equal to or greater than the amount of electrolyte flowing in the battery cell, and may be larger than the amount of electrolyte flowing in the battery cell. In that case, it is preferable that the amount of the electrolytic solution flowing in the battery cell is, for example, four times or less so that the recovery space portion does not become excessively large.

  As one form of the electrolyte flow type battery of the present invention, the first opening / closing means is a valve.

  According to this configuration, the first opening / closing means can be easily realized by using the valve. The valve used for the first opening / closing means is not particularly limited as long as the recovery passage can be opened and closed, and may be either a manual valve or an automatic valve.

  As an embodiment of the electrolyte flow type battery of the present invention, the first opening / closing means is an automatic valve, and has a first opening / closing means control unit for controlling the first opening / closing means. For example, when the pump is stopped, the collection passage is opened through the first opening / closing means.

  According to this configuration, by including the first opening / closing means control unit, when the circulation pump is stopped, the recovery passage is automatically opened, and the work of extracting the electrolyte in the battery cell can be automatically performed. Moreover, since the liquid draining operation in the battery cell is automatically performed, it is simpler than the case of manually performing the operation, and human error can be prevented. As the automatic valve, for example, an electric or pneumatic type can be used.

  Further, in the embodiment having the first opening / closing means control section, the first opening / closing means control section preferably closes the collection passage via the first opening / closing means when the circulation pump is activated.

  According to this configuration, the recovery passage is automatically closed when the circulation pump is activated, and the electrolyte to be circulated does not flow into the recovery space during the operation of the battery.

  As one form of the electrolyte flow type battery of the present invention, it may be provided with a second opening / closing means for opening / closing the forward piping.

  According to this configuration, when the circulation pump is stopped, the outward piping is closed via the second opening / closing means, so that the electrolytic solution in the electrolyte tank does not flow into the recovery space through the outward piping. Can do. On the other hand, when the circulation pump is activated and the battery is operating, the outward piping is opened via the second opening / closing means, and the electrolytic solution is circulated through the circulation path.

  In the embodiment including the second opening / closing means described above, the second opening / closing means may be a valve.

  According to this configuration, the second opening / closing means can be easily realized by using the valve. The valve used for the second opening / closing means is not particularly limited as long as it can open and close the outward piping, and may be either a manual valve or an automatic valve.

  In the embodiment including the second opening / closing means described above, the second opening / closing means is an automatic valve, and has a second opening / closing means control unit for controlling the second opening / closing means, and the second opening / closing means control unit has the circulation pump stopped. When closing, it is possible to close the forward piping via the second opening / closing means.

  According to this configuration, by including the second opening / closing means control unit, when the circulation pump is stopped, the forward piping is automatically closed, and the operation of closing the outward piping can be automatically performed. Further, since the closing operation of the outward piping is automatically performed, it is simpler than the case where it is manually performed, and human error can be prevented. As the automatic valve, for example, an electric or pneumatic type can be used.

  Further, in the embodiment having the above-described second opening / closing means control section, it is preferable that the second opening / closing means control section opens the outward piping via the second opening / closing means when the circulation pump is activated.

  According to this configuration, when the circulation pump is activated, the outward piping is automatically opened, and the operation of the battery can be started.

  More preferably, each of the first opening / closing means and the second opening / closing means is an automatic valve, and includes a first opening / closing means control unit for controlling the first opening / closing means and a second opening / closing means control unit for controlling the second opening / closing means. The form provided with the control means which has is mentioned. When the circulating pump is stopped, the control means closes the forward piping via the second opening / closing means by the second opening / closing means control section and opens the recovery passage via the first opening / closing means by the first opening / closing means control section. . Further, when the circulation pump is started, the recovery passage is closed by the first opening / closing means control unit via the first opening / closing means, and the outward piping is opened by the second opening / closing means control unit via the second opening / closing means.

  This configuration has the above-described first opening / closing means control section and second opening / closing means control section. Therefore, according to this configuration, when the circulation pump is stopped, the recovery passage is automatically opened and the outward piping is automatically closed, so that the electrolytic solution in the electrolyte tank does not flow into the recovery space through the outward piping. However, the electrolytic solution in the battery cell can be automatically collected in the collection space through the collection passage. Further, when the circulation pump is activated, the operation of the battery can be started while the recovery passage is automatically closed and the outward piping is automatically opened so that the electrolyte to be circulated does not flow into the recovery space. That is, the opening / closing operation of the recovery passage and the outward piping according to the state of the circulation pump can be completely automated, and the operation of draining the liquid in the battery cell and the operation of starting the battery can be performed automatically and accurately. Therefore, these operations can be performed reliably and accurately, and this is particularly effective when applied to applications where the stop and start of the circulation pump are repeated.

  As one form of the electrolyte flow type battery of the present invention, the outgoing pipe is provided with a high position portion disposed at a position higher than the liquid level of the electrolyte in the electrolyte tank, and the gas phase in the electrolyte tank It is possible to provide a first gas-phase pipe for communicating the part and the high position part and moving the gas phase in the electrolyte tank to the high position part.

  According to this configuration, the high-position portion is provided in the outward piping, so that when the circulation pump is stopped, the electrolyte solution in the electrolyte tank does not flow beyond the high-position portion to the battery cell side. it can. Therefore, the electrolytic solution in the electrolytic solution tank can be prevented from flowing into the recovery space through the outward piping. In this case, the second opening / closing means (eg, a valve) as described above can be omitted. In addition, by providing the first gas phase piping, the gas phase in the electrolyte tank moves to a high position, and the forward piping (high position) is prevented from becoming negative pressure. The siphon principle can prevent the battery cell from flowing. The first vapor phase pipe is preferably provided with a check valve so that the electrolyte in the forward line does not flow backward to the first vapor line. In addition, a valve may be used instead of the check valve, and the first gas-phase pipe may be opened through this valve when the circulation pump is stopped. It should be noted that at least one high-position portion of the forward piping is sufficient.

  As one form of the electrolyte flow type battery of the present invention, the recovery space and the electrolyte tank are communicated, and the return pipe for returning the electrolyte in the recovery space to the electrolyte tank, and the return pipe And a liquid feed pump for feeding the electrolytic solution in the recovery space to the electrolytic solution tank.

  According to this configuration, the electrolyte solution collected in the recovery space portion can be reused by feeding the electrolyte solution in the recovery space portion to the electrolyte solution tank using the liquid feed pump via the return pipe. The work of returning the electrolytic solution in the recovery space to the electrolytic solution tank (returning the electrolytic solution to the electrolytic solution tank) can be performed manually by an operator, but the circulation pump is repeatedly stopped and started. In the case of use, work can be efficiently performed by applying this configuration. In addition, the liquid returning operation to the electrolytic solution tank may be performed, for example, during the draining operation in the battery cell or during the operation of the battery.

  In the embodiment including the above-described liquid feed pump, the liquid feed pump may be an electric pump or an air pump.

  An electric pump or an air pump can be used as the liquid feed pump. These pumps are highly versatile and easy to implement. When using an air pump, for example, air (gas) is supplied from the air pump to the recovery space, and the electrolyte in the recovery space is pushed out by that pressure, and the electrolyte in the recovery space is supplied to the electrolyte tank via the return pipe. Pumping can be mentioned.

  In the form provided with the above-mentioned liquid feed pump, it has a secondary battery or an uninterruptible power supply, and supplies power to a liquid feed pump from a secondary battery or an uninterruptible power supply (UPS). .

  When a commercial power source is used as a power source for a liquid feed pump (eg, an electric pump or an air pump), liquid return work to the electrolyte tank cannot be performed by the liquid feed pump at the time of a power failure. Therefore, according to this configuration, by using a secondary battery or an uninterruptible power supply for the power supply of the liquid feed pump, the liquid return operation to the electrolyte tank by the liquid feed pump can be performed even during a power failure. Can do.

  In the embodiment provided with the liquid feeding pump described above, it is possible to supply power from the battery cell to the liquid feeding pump.

  In the electrolyte flow type battery of the present invention, the operation of draining the battery cell is performed when the circulation pump is stopped for the purpose of suppressing self-discharge. Here, a certain amount of time is required until the electrolyte in the battery cell is completely removed, and a voltage is generated in the battery cell during this time. That is, during this period, power can be supplied from the battery cell to the liquid feed pump. Therefore, according to this configuration, by using the battery cell as a power source of the liquid feeding pump, the voltage of the battery cell generated during the liquid draining operation in the battery cell can be effectively used, and the electrolyte tank by the liquid feeding pump can be used. The liquid return operation can be executed. Moreover, it is not necessary to have a secondary battery or an uninterruptible power supply as a power source for the liquid feeding pump. On the other hand, when the voltage of the battery cell is lost by supplying power from the battery cell and operating the liquid feeding pump (the power generation capacity of the battery is lost), a part of the electrolyte remains in the battery cell. In any case, since the self-discharge cannot occur in the first place, the liquid draining operation in the battery cell may be stopped.

  In the embodiment including the above-described liquid feed pump, a second gas phase pipe is provided for communicating the gas phase portion in the electrolyte tank and the recovery space portion and moving the gas phase in the electrolyte tank to the recovery space portion. It is preferable.

  If the liquid feed pump is started with the collection passage closed and the electrolyte in the collection space is sent to the electrolyte tank, the collection space becomes negative pressure and the collection space may be damaged. According to this configuration, by providing the second gas-phase piping, the gas-phase in the electrolyte tank moves to the recovery space, prevents the recovery space from becoming negative pressure, and prevents the recovery space from being damaged. it can. That is, regardless of the state of opening and closing the recovery passage, even when the battery is in operation, for example, it is easy to perform the liquid return operation to the electrolyte tank by the liquid feeding pump.

  In the embodiment including the liquid feeding pump described above, the liquid amount detecting means for detecting the liquid amount of the electrolytic solution in the recovery space section and the liquid feeding pump control section for controlling the liquid feeding pump are provided, and the liquid amount detecting means In addition, when it is detected that the amount of the electrolytic solution in the recovery space portion has exceeded a predetermined upper limit, the liquid feed pump control unit starts the liquid feed pump, and the liquid feed pump starts the liquid feed. .

  According to this configuration, when the amount of the electrolytic solution in the recovery space portion exceeds a predetermined upper limit, the liquid feeding pump automatically starts liquid feeding, so that the liquid returning operation to the electrolytic solution tank is automatically performed. The liquid draining operation in the battery cell can be repeated. Moreover, since the liquid return operation to the electrolyte tank is automatically performed, it is simpler than that performed manually (manual operation), and human error can be prevented.

  The liquid amount detecting means is not particularly limited as long as it can detect the amount of the electrolytic solution in the collection space, and for example, a sensor or a switch can be used. Examples of the sensor include various liquid level sensors and liquid amount sensors such as an optical type, a capacitance type, an ultrasonic type, and a float type. Examples of the switch include a level switch such as a float switch.

  In the embodiment having the liquid feeding pump control unit described above, when the liquid amount detecting means detects that the amount of the electrolytic solution in the recovery space portion has become equal to or lower than a predetermined lower limit, the liquid feeding pump control unit detects the liquid feeding pump. It is preferable that the liquid feed pump stops the liquid feed.

  According to this configuration, when the amount of the electrolytic solution in the recovery space portion becomes equal to or lower than the predetermined lower limit, the liquid feeding pump automatically stops liquid feeding, so that the liquid returning operation to the electrolytic solution tank is automatically terminated. be able to.

  In the embodiment having the liquid feed pump control unit described above, the liquid feed pump control unit has a timer, and when the timer detects that a predetermined time has elapsed since the start of the liquid feed pump, the liquid feed pump control unit It is preferable that the liquid pump is stopped and the liquid supply pump stops the liquid supply.

  According to this configuration, when a predetermined time has elapsed since the start of the liquid feeding pump, the liquid feeding pump automatically stops liquid feeding, so that the liquid return operation to the electrolyte tank can be automatically terminated. . In this case, it is not necessary to detect that the amount of the electrolytic solution in the recovery space portion has become equal to or lower than the predetermined lower limit by the liquid amount detecting means.

  In the embodiment provided with the second opening / closing means described above, in the event of a power failure, the second opening / closing means is activated to open the outgoing piping, and the electrolytic solution is supplied from the electrolyte tank to the battery cell, thereby supplying power from the battery cell to the circulation pump. Supply.

  In the present invention, when the circulation pump is stopped, the electrolytic solution in the battery cell is recovered in the recovery space, and the battery cell is empty. According to this configuration, in an emergency such as a power outage, the outward piping is opened, and the electrolyte is routed from the electrolytic solution tank to the battery cell due to the difference in hydraulic pressure (head pressure) between the electrolytic solution tank and the battery cell. Supplied automatically through. And by supplying electrolyte solution in a battery cell, the voltage of a battery cell rises and the electric power supply from a battery cell to a circulation pump is attained. By supplying this electric power to the circulation pump, the circulation pump can be activated to start the operation of the battery. By continuing to supply power from the battery cell to the circulation pump after the start of battery operation, the battery operation can be continued even in an emergency such as a power failure.

  One embodiment of the electrolyte flow type battery of the present invention is a redox flow battery.

It does not specifically limit as a redox flow battery, For example, it is mentioned that the electrolyte solution of positive and negative electrodes is either of the following (1)-(5).
(1) The positive electrode electrolyte contains manganese ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, zinc ions, and tin ions.
(2) The positive electrode electrolyte contains both manganese ions and titanium ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, zinc ions, and tin ions. .
(3) Each of the positive and negative electrode electrolyte solutions contains both manganese ions and titanium ions.
(4) The positive and negative electrode electrolytes each contain vanadium ions.
(5) The positive electrode electrolyte contains iron ions, and the negative electrode electrolyte contains at least one metal ion selected from titanium ions, vanadium ions, chromium ions, zinc ions, and tin ions.

  By setting the positive and negative electrode electrolytes to any one of the above (1) to (5), a redox flow battery suitable for the electrolyte flow battery system of the present invention can be configured. In particular, as the electrolytic solutions (1) and (2), high electromotive force can be obtained by using manganese ions as the positive electrode active material and titanium ions and vanadium ions listed above as the negative electrode active material. A high electromotive force can be obtained by using manganese ions for the positive electrode active material and titanium ions for the negative electrode active material as the electrolyte solution of (3) above. Furthermore, as the electrolyte solution of the above (2) and (3), the positive electrode active material is manganese ions, and by separately containing titanium ions, a high electromotive force is obtained, and precipitates that increase the battery resistance are obtained. Generation | occurrence | production can be suppressed effectively. As the electrolyte solution of the above (5), a configuration in which the positive electrode electrolyte solution contains iron ions and the negative electrode electrolyte solution contains chromium ions is preferable.

  When the circulation pump is stopped, the electrolyte flow type battery of the present invention can remove the electrolyte in the battery cell, and can effectively suppress self-discharge.

It is a schematic diagram for demonstrating the redox flow battery which concerns on Embodiment 1, and shows the state which the circulation pump started. It is a schematic diagram for demonstrating the redox flow battery which concerns on Embodiment 1, and shows the state which the circulation pump stopped. 3 is a functional block diagram of control means in the redox flow battery according to Embodiment 1. FIG. 3 is a flowchart showing an operation sequence of control means in the redox flow battery according to the first embodiment. It is a schematic diagram for demonstrating the redox flow battery which concerns on Embodiment 2, and shows the state which the circulation pump started. It is a schematic diagram for demonstrating the redox flow battery which concerns on Embodiment 2, and shows the state which the circulation pump stopped. 6 is a schematic diagram for explaining a redox flow battery according to Embodiment 3. FIG. 10 is a schematic diagram for explaining a redox flow battery according to modification example 7. FIG. It is a schematic diagram for demonstrating the conventional redox flow battery. It is a schematic diagram for demonstrating a cell stack.

  Embodiments of the present invention will be described with reference to the drawings. In the embodiment described below, a vanadium redox flow battery will be described as an example. In the drawings, the same reference numerals indicate the same or corresponding parts.

(Embodiment 1)
The redox flow battery 1 according to the first embodiment shown in FIGS. 1 and 2 includes a basic configuration of the battery cell 10 and each electrolyte tank 20 for positive and negative electrodes, each circulation path 30 and each circulation pump 40. This is the same as the conventional redox flow battery 4 described with reference to FIG. Therefore, the description of the basic configuration is omitted here, and the difference from the conventional battery will be mainly described.

  The redox flow battery 1 includes a collection space 50 for collecting the electrolyte in the battery cell 10, a collection passage 51 that communicates the battery cell 10 and the collection space 50, and a first opening / closing that opens and closes the collection passage 51. Means 55 and second opening / closing means 56 for opening and closing the forward piping 31 are provided. In this example, the collection space 50, the collection passage 51, the first opening / closing means 55, and the second opening / closing means 56 are provided for the positive electrode and the negative electrode, respectively. In addition, the redox flow battery 1 includes a battery cell 10 and an electrolyte solution tank 20 arranged substantially horizontally.

  The collection space 50 is installed at a position lower than the battery cell 10, and in this example, the volume (for example, equal to or more than the amount of the electrolyte flowing in the battery cell 10 (positive electrode cell 102, negative electrode cell 103)) 100 to 200 liters). The collection space 50 is a flat container-like tank, for example. In this example, the lower part of the battery cell 10 and the collection space 50 are directly connected by the collection passage 51.

  The first opening / closing means 55 and the second opening / closing means 56 are valves, and in this example, automatic valves are used. Further, as shown in FIG. 3, the redox flow battery 1 includes a first opening / closing means controller 91 for controlling the first opening / closing means 55 and a second opening / closing means controller 92 for controlling the second opening / closing means 56. Control means 90 is provided. The control means 90 can be realized by a sequence circuit using a computer or a relay. The control means 90 operates as follows according to the state of the circulation pump 40, for example, a stop / start signal of the circulation pump 40. When the circulation pump 40 stops, the second opening / closing means control unit 92 closes the outward piping 31 via the second opening / closing means 56 and the first opening / closing means control unit 91 passes the first opening / closing means 55 through the recovery passageway. Open 51. When the circulation pump 40 is activated, the first opening / closing means control unit 91 closes the collection passage 51 via the first opening / closing means 55 and the second opening / closing means control unit 92 via the second opening / closing means 56. The outward piping 31 is opened (see FIGS. 1 to 3).

  The operation of the redox flow battery 1 when the circulation pump 40 is stopped or started will be described with reference to the flowchart shown in FIG.

  When the circulation pump 40 is started and the electrolytic solution is circulated through the circulation path 30, the outward piping 31 is open, and like the conventional battery, from the electrolytic solution tank 20 via the outward piping 31. The electrolytic solution is sent to the battery cell 10, and the electrolytic solution that has passed through the battery cell 10 is returned to the electrolytic solution tank 20 through the return pipe 32 and circulated. Further, the recovery passage 51 is closed, and the electrolyte circulated through the circulation path 30 does not flow into the recovery space 50 during operation (see FIG. 1).

  Next, when the circulation pump 40 stops, the recovery passage 51 automatically opens, and the electrolytic solution in the battery cell 10 (the positive electrode cell 102 and the negative electrode cell 103) is recovered through the recovery passage 51 into the recovery space 50. . That is, the electrolytic solution in the battery cell 10 is removed. At this time, the outward piping 31 is automatically closed, and the electrolytic solution in the electrolyte tank 20 does not flow into the recovery space 50 through the outward piping 31 (see FIG. 2). Specifically, as shown in the flowchart of the control means of FIG. 4, when the stop / start signal of the circulation pump 40 is received and the stop signal of the circulation pump 40 is received, the circulation pump 40 is stopped and the second opening / closing is performed. The outward piping 31 is closed via the means 56, the recovery passage 51 is opened via the first opening / closing means 55, and the process ends. Here, it is preferable to close the outward piping 31 before opening the recovery passage 51, because the electrolyte in the electrolyte tank 20 can be reliably prevented from flowing into the recovery space 50 through the outward piping 31.

  When the circulation pump 40 is started again and the operation is started, the recovery passage 51 is automatically closed and the outward piping 31 is automatically opened, so that the electrolyte to be circulated through the circulation path 30 flows into the recovery space 50. The operation is started by circulating the electrolyte through the circulation path 30 (see FIG. 1). Specifically, as shown in the flowchart of the control means in FIG. 4, a stop / start signal for the circulation pump 40 is received, and if it is the start signal for the circulation pump 40, the recovery passage is connected via the first opening / closing means 55. 51 is closed, the outward piping 31 is opened via the second opening / closing means 56, the circulation pump 40 is started, and the process is terminated. Also in this case, it is preferable to close the recovery passage 51 before opening the outward piping 31, since it is possible to reliably prevent the electrolyte circulated through the circulation path 30 from flowing into the recovery space 50.

  Since the redox flow battery 1 according to the first embodiment described above can drain the electrolytic solution in the battery cell 10 when the circulation pump 40 is stopped, the electrolytic solution remains in the battery cell 10. Self-discharge can be suppressed. Therefore, it is possible to reduce the decrease in the discharge capacity of the battery due to the self-discharge and the deterioration of the constituent members of the battery cell 10 due to the heat generation of the electrolyte due to the self-discharge. In addition, since the volume of the recovery space 50 is equal to or greater than the amount of the electrolyte flowing through the battery cell 10, the electrolyte remaining in the battery cell 10 can be completely removed. Furthermore, since the control means automatically opens and closes the collection passage 51 and the outward piping 31 according to the state of the circulation pump 40, the operation of draining the battery cell and starting the operation of the battery can be performed automatically and accurately. Can do. In particular, in an application in which the circulation pump 40 is repeatedly stopped and started, these operations can be performed reliably and accurately, so that the effect is great.

(Embodiment 2)
The redox flow battery 2 according to the second embodiment shown in FIGS. 5 and 6 is that the high-position portion 35 is provided in the forward piping 31 because the redox according to the first embodiment described with reference to FIGS. Different from the flow battery 1. Therefore, here, the difference from the redox flow battery 1 will be mainly described.

  The redox flow battery 2 is replaced with the second opening / closing means 56 of the redox flow battery 1, and the high position portion 35 disposed in the outgoing pipe 31 at a position higher than the liquid level of the electrolyte 21 in the electrolyte tank 20. Is provided. Further, a first gas phase pipe 60 is provided for communicating the gas phase portion 22 in the electrolyte tank 20 and the high position portion 35 and moving the gas phase in the electrolyte tank 20 to the high position portion 35. The first gas phase pipe 60 is provided with a check valve 61. In this example, the high position portions 35 are provided in the forward piping 31 for the positive electrode and the negative electrode, respectively.

  The operation of the redox flow battery 2 when the circulation pump 40 is stopped or started will be described.

  When the circulation pump 40 is activated and is operated by circulating the electrolyte through the circulation path 30, the electrolyte is sent from the electrolyte tank 20 to the battery cell 10 via the forward piping 31 as in the conventional battery. Then, the electrolytic solution that has passed through the battery cell 10 is returned to the electrolytic solution tank 20 via the return pipe 32 and circulated. Further, like the redox flow battery 1, the collection passage 51 is closed, and the electrolyte circulated through the circulation path 30 does not flow into the collection space 50 during operation (see FIG. 5).

  Next, when the circulation pump 40 stops, the recovery passage 51 automatically opens, and the electrolytic solution in the battery cell 10 (the positive electrode cell 102 and the negative electrode cell 103) is recovered through the recovery passage 51 into the recovery space 50. . Further, at this time, the liquid level of the electrolytic solution in the outward piping 31 becomes equal to the liquid level of the electrolytic solution in the electrolytic solution tank 20, and the electrolytic solution in the electrolytic solution tank 20 exceeds the high position portion 35 and is on the battery cell 10 side. Does not flow. Therefore, the electrolytic solution in the electrolytic solution tank 20 does not flow into the recovery space portion 50 through the outward piping 31 (see FIG. 6). In other words, in the redox flow battery 2, the high position portion 35 is provided in the outward piping 31, and the first gas phase piping 60 is connected to the high position portion 35, so that the electrolytic solution in the electrolyte tank 20 is recovered in the recovery space portion 50. Is prevented from flowing into. On the other hand, in the redox flow battery 1, the electrolyte solution in the electrolyte tank 20 flows into the recovery space 50 by closing the outward piping 31 via the second opening / closing means 56 when the circulation pump 40 is stopped. It is preventing.

  When the circulation pump 40 is activated again and starts operation, the recovery passage 51 is automatically closed in the same manner as the redox flow battery 1 so that the electrolyte to be circulated through the circulation path 30 does not flow into the recovery space 50. In the meantime, the electrolytic solution is circulated through the circulation path 30 to start the operation (see FIG. 5).

  The redox flow battery 2 according to the second embodiment described above has the same effect with a simple configuration even if the second open / close means 56 is not provided in the forward piping 31 unlike the redox flow battery 1 according to the first embodiment. Can be expected. Further, by connecting the gas phase portion in the electrolyte tank 20 and the high position portion 35 with the first gas phase piping 60, the gas phase in the electrolyte tank 20 is at the high position portion during the draining operation in the battery cell. 35, the forward piping 31 (high position portion 35) can be prevented from becoming negative pressure, and the electrolytic solution in the electrolytic solution tank 20 can be prevented from flowing to the battery cell 10 side by the siphon principle. Further, since the check valve 61 is provided in the first gas-phase pipe 60, the electrolytic solution in the forward-path pipe 31 does not flow back to the first gas-phase pipe 60.

  Next, various modifications of the redox flow batteries 1 and 2 according to the first and second embodiments will be described.

(Modification 1)
In the redox flow batteries 1 and 2 described above, the case where the lower part of the battery cell 10 and the recovery space part 50 are directly connected by the recovery passage 51 has been described as an example, but instead of the lower part of the battery cell 10, the battery cell 10 The recovery passageway 51 may be connected to the middle of the outward piping 31 located below. In this case, in the case of the redox flow battery 1, the recovery passage 51 is connected in the middle of the outward piping 31 on the battery cell 10 side than the second opening / closing means 56, and in the case of the redox flow battery 2, A recovery passage 51 is connected in the middle of the outward piping 31 on the battery cell 10 side.

(Modification 2)
In the redox flow battery 1 described above, the case where the first opening / closing means 55 and the second opening / closing means 56 are automatic valves and the collection passage 51 and the outward piping 31 are automatically opened and closed by the control means has been described as an example. Either one or both of the first opening / closing means 55 and the second opening / closing means 56 may be a manual valve. In this case, when the circulation pump 40 is stopped or started, either one or both of the first opening / closing means 55 and the second opening / closing means 56, which are manual valves, are manually operated to One or both opening and closing operations are performed manually. Similarly, in the redox flow battery 2 described above, the first opening / closing means 55 may be a manual valve. In this case, when the circulation pump 40 is stopped or started, the first opening / closing means 55 is manually operated, The collection passage 51 is manually opened and closed.

(Modification 3)
In the above-described redox flow batteries 1 and 2, the case where the recovery space 50 is provided for each of the positive electrode and the negative electrode has been described as an example, but the recovery space 50 may be provided only for either the positive electrode or the negative electrode. Good. Even in this case, an effect of suppressing self-discharge can be expected.

(Modification 4)
In the redox flow battery 1 described above, when the power failure occurs, the second opening / closing means 56 is actuated to open the outward piping 31 and supply the electrolyte from the electrolyte tank 20 to the battery cell 10. You may add the structure which supplies electric power to.

  In the redox flow battery 1 described above, as shown in FIG. 2, when the circulation pump 40 is stopped, the electrolyte in the battery cell 10 is recovered in the recovery space 50, and the battery cell 10 is empty. On the other hand, the electrolytic solution is stored in the electrolytic solution tank 20. Therefore, if the second opening / closing means 56 is activated to automatically open the outward piping 31 in the event of an emergency such as a power failure, the head pressure difference between the electrolyte tank 20 and the battery cell 10 can be reduced. The electrolytic solution is automatically supplied from the electrolytic solution tank 20 to the battery cell 10 through the outward piping 31. Then, when the electrolytic solution is supplied into the battery cell 10, the voltage of the battery cell 10 is increased, and power supply from the battery cell 10 to the circulation pump 40 becomes possible. By supplying this electric power to the circulation pump 40, the circulation pump 40 can be started and the operation of the battery can be started. By continuing to supply power from the battery cell 10 to the circulation pump 40 after the start of battery operation, the battery operation can be continued even in an emergency such as a power failure. When the second opening / closing means 56 is a manual valve, the second opening / closing means 56 may be manually operated to open the outward piping 31 in an emergency such as a power failure. In addition, when this configuration is added, it is preferable to close the collection passage 51 via the first opening / closing means 55 in the event of a power failure or the like, and the first opening / closing means 55 is activated to automatically make the collection passage 51 open. It is preferable to be configured to be closed.

  In order to configure the second opening / closing means 56 to automatically open the outgoing piping 31 at the time of a power failure, for example, an auxiliary power source for operating the second opening / closing means (eg, a secondary battery or an uninterruptible power supply) is used. What is necessary is just to prepare separately and supply electric power to the 2nd opening-and-closing means 56 from this auxiliary power supply. Similarly, in order to configure the first opening / closing means 55 to automatically close the collection passage 51 at the time of a power failure, for example, an auxiliary power source for operating the first opening / closing means (e.g., secondary battery or uninterruptible power supply). A power supply device) may be prepared separately, and power may be supplied to the first opening / closing means 55 from this auxiliary power supply.

(Embodiment 3)
The redox flow battery 3 according to the third embodiment shown in FIG. 7 is different from the redox flow battery 1 according to the first embodiment described with reference to FIGS. Is different. Therefore, here, the difference from the redox flow battery 1 will be mainly described.

  The redox flow battery 3 communicates the recovery space 50 and the electrolyte tank 20, and through the return pipe 70 for returning the electrolyte in the recovery space 50 to the electrolyte tank 20, and the return pipe 70, A liquid feed pump 71 for feeding the electrolytic solution in the collection space 50 to the electrolytic solution tank 20;

  In this example, the liquid feed pump 71 is an electric pump, and is attached in the middle of the return pipe 70. The return pipe 70 is connected so as to communicate the lower part of the recovery space 50 and the upper part of the electrolyte tank 20. Here, an air pump may be used as the liquid feed pump. In the case of using an air pump, for example, an air pump is attached to the recovery space 50, air (gas) is supplied from the air pump, the electrolyte in the recovery space 50 is extruded with the pressure, and the recovery space 70 is returned via the return pipe 70. It can be considered that the electrolytic solution in the part 50 is pumped to the electrolytic solution tank 20.

  As described above, the electrolytic solution in the battery cell 10 is collected in the collection space 50 when the circulation pump 40 is stopped. According to the redox flow battery 3, the electrolyte in the collection space 50 can be sent (returned) to the electrolyte tank 20 using the feed pump 71 via the return pipe 70, and collected in the collection space 50. The used electrolyte can be reused. In particular, in applications where the circulation pump 40 is repeatedly stopped and started, the liquid return work to the electrolytic solution tank can be efficiently performed by the liquid feed pump 71, which is highly effective. Needless to say, the operation of returning the liquid to the electrolytic solution tank can be performed manually by an operator using a manual pump or a bucket. In addition, the liquid returning operation to the electrolytic solution tank may be performed, for example, during the draining operation in the battery cell or during the operation of the battery.

  Here, the case where the return pipe 70 and the liquid feed pump 71 are added to the redox flow battery 1 according to the first embodiment has been described as an example. However, also in the redox flow battery 2 according to the second embodiment, Of course, the return pipe and the liquid feed pump can be added in the same manner.

(Modification 5)
The above-described redox flow battery 3 may include a configuration in which an auxiliary power source such as a secondary battery or an uninterruptible power supply is provided and power is supplied from the auxiliary power source to the liquid feeding pump.

  When a commercial power source is used as the power source of the liquid feed pump 71 (eg, electric pump or air pump), the liquid return operation to the electrolyte tank by the liquid feed pump 71 cannot be performed during a power failure. Therefore, by using an auxiliary power source (for example, a secondary battery or an uninterruptible power supply) as the power source for the liquid pump 71, liquid return work to the electrolyte tank is performed by the liquid pump 71 even during a power failure. can do.

(Modification 6)
In the redox flow battery 3 described above, a configuration for supplying power from the battery cell 10 to the liquid feeding pump 71 may be added.

  At the time of draining the liquid in the battery cell, a certain amount of time is required until the electrolyte in the battery cell 10 is completely removed, and voltage is generated in the battery cell 10 during this time. That is, power can be supplied from the battery cell 10 to the liquid feed pump 40 during this period. Therefore, by using the battery cell 10 as the power source of the liquid feeding pump 71, the voltage of the battery cell 10 generated during the liquid draining operation in the battery cell 10 can be effectively used, and the liquid feeding pump 71 can supply the electrolyte tank to the electrolyte tank. Liquid return operation can be performed. Further, it is not necessary to separately have a secondary battery or an uninterruptible power supply as a power source for the liquid feed pump 71. On the other hand, when power is supplied from the battery cell 10 and the liquid feeding pump 71 is operated so that the voltage of the battery cell 10 is lost (the power generation capacity of the battery is lost), the electrolytic solution is completely stored in the battery cell 10. Even if a part remains, since the self-discharge cannot occur in the first place, the liquid draining operation in the battery cell may be stopped.

(Modification 7)
In the redox flow battery 3 described above, as shown in FIG. 8, the gas phase portion in the electrolyte solution tank 20 and the recovery space portion 50 are communicated, and the gas phase in the electrolyte solution tank 20 is moved to the recovery space portion 50. A configuration including a second gas-phase pipe 80 may be added.

  In the redox flow battery 3 shown in FIG. 7, the liquid feeding pump 71 is activated with the collection passage 51 closed via the first opening / closing means 55, and the electrolytic solution in the collection space 50 is fed to the electrolytic solution tank 20. Then, the recovery space part becomes negative pressure, and the recovery space part may be damaged. Therefore, as shown in FIG. 8, the liquid return operation to the electrolyte tank by the liquid feed pump 71 is performed by connecting the gas phase portion in the electrolyte tank 20 and the recovery space portion 50 by the second gas phase pipe 80. Occasionally, the gas phase in the electrolyte tank 20 moves to the recovery space 50, preventing the recovery space 50 from becoming a negative pressure and preventing the recovery space 50 from being damaged. That is, regardless of whether the recovery passage 51 is opened or closed, the liquid return operation to the electrolyte tank by the liquid feeding pump 71 is easy even when the battery is in operation, for example.

(Modification 8)
In the redox flow battery 3 described above, a configuration having a liquid amount detecting means for detecting the amount of the electrolytic solution in the recovery space 50 and a liquid feed pump control unit for controlling the liquid feed pump 71 may be added. Good.

  The liquid amount detection means is not particularly limited as long as it can detect the amount of the electrolytic solution in the collection space 50, and for example, a sensor or a switch can be used. Examples of the sensor include various liquid level sensors and liquid amount sensors such as an optical type, a capacitance type, an ultrasonic type, and a float type. Examples of the switch include a level switch such as a float switch. Further, the liquid feed pump control unit may be realized by a sequence circuit using a relay or the like, in addition to being incorporated in the control unit (computer) having the first opening / closing unit control unit and the second opening / closing unit control unit described above.

  In the redox flow battery according to the modified example 8, when the liquid amount detecting means detects that the amount of the electrolytic solution in the recovery space portion 50 has exceeded a predetermined upper limit, the liquid supply pump control unit detects the liquid supply pump. 71 is started, and the liquid feeding pump 71 starts liquid feeding. Accordingly, when the amount of the electrolytic solution in the recovery space portion 50 exceeds a predetermined upper limit, the liquid feeding pump 71 automatically starts liquid feeding, so that the liquid returning operation to the electrolytic solution tank 20 is automatically performed. be able to. Further, even if the liquid draining operation in the battery cell is repeated, the inside of the collection space 50 is not filled with the collected electrolyte. Furthermore, even when the volume of the recovery space 50 is smaller than the amount of electrolyte flowing through the battery cell 10, the draining operation in the battery cell is not hindered until the electrolyte in the battery cell 10 is completely removed. Can be executed.

(Modification 9)
In the redox flow battery of the above-described modified example 8, when the liquid amount detecting means detects that the amount of the electrolytic solution in the recovery space portion 50 is equal to or lower than a predetermined lower limit, the liquid supply pump control unit supplies the liquid. A configuration in which the pump 71 is stopped and the liquid feeding pump 71 stops liquid feeding may be added.

  In the redox flow battery of this modified example 9, when the amount of the electrolytic solution in the recovery space portion 50 is equal to or lower than a predetermined lower limit, the liquid feeding pump 71 automatically stops liquid feeding. The return operation can be automatically terminated.

(Modification 10)
In the redox flow battery of Modification 8 described above, the liquid feed pump control unit has a timer, and when the timer detects that a predetermined time has elapsed since the start of the liquid feed pump 71, the liquid feed pump control unit A configuration may be added in which the liquid pump 71 is stopped and the liquid supply pump 71 stops liquid supply.

  In the redox flow battery of this modified example 10, when a predetermined time has elapsed since the start of the liquid feeding pump 71, the liquid feeding pump 71 automatically stops liquid feeding, so that the liquid returning operation to the electrolyte tank is automatically performed. It can be finished with. In the redox flow battery of Modification 9 described above, it is necessary to detect that the amount of the electrolytic solution in the recovery space 50 is equal to or lower than a predetermined lower limit by the liquid amount detecting means. On the other hand, in the Redox flow battery of the modified example 10, since the timer is used, it is not detected by the liquid amount detecting means that the amount of the electrolytic solution in the recovery space portion 50 has become a predetermined lower limit or less. Also good. Therefore, the liquid amount detection means only needs to detect that the amount of the electrolytic solution in the recovery space has reached a predetermined upper limit, and the number of sensors and switches described above can be reduced.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, you may change suitably the kind of electrolyte solution, the kind of valve | bulb used for a 1st opening / closing means and a 2nd opening / closing means.

  The electrolyte flow type battery of the present invention can be suitably used for a large-capacity storage battery for the purpose of smoothing output fluctuations, storing surplus power, leveling loads, and the like.

1,2,3,4 electrolyte flow type battery (redox flow battery)
10 battery cells
101 Diaphragm 102 Positive electrode cell 103 Negative electrode cell
104 Positive electrode 105 Negative electrode
20 Electrolyte tank
21 Electrolyte 22 Gas phase part
30 Circulation path
31 Outward piping 32 Return piping 35 High position
40 Circulation pump
200 cell stack
201 Bipolar plate 202 Cell frame
210 End plate 220 Fastener
50 Collection space 51 Collection passage
55 First opening / closing means 56 Second opening / closing means
60 First gas phase piping 61 Check valve
70 Return piping 71 Liquid feed pump
80 Second gas phase piping
90 Control means
91 First opening / closing means control section 92 Second opening / closing means control section

Claims (21)

A battery cell;
An electrolyte tank for storing the electrolyte;
A circulation path having an outward piping for sending the electrolytic solution from the electrolytic solution tank to the battery cell, and a return piping for returning the electrolytic solution from the battery cell to the electrolytic solution tank;
An electrolyte flow type battery comprising a circulation pump for circulating the electrolyte in the circulation path,
Installed in a position lower than the battery cell, and a recovery space for recovering the electrolyte in the battery cell;
A collection passage communicating the battery cell and the collection space;
And a first open / close means for opening and closing the recovery passage.   2. The electrolyte flow type battery according to claim 1, wherein the volume of the recovery space portion is equal to or greater than the amount of the electrolyte solution flowing in the battery cell.   3. The electrolyte flow type battery according to claim 1, wherein the first opening / closing means is a valve. The first opening / closing means is an automatic valve;
A first opening / closing means controller for controlling the first opening / closing means;
The electrolysis according to any one of claims 1 to 3, wherein the first opening / closing means controller opens the recovery passage through the first opening / closing means when the circulation pump stops. Liquid-flow battery.   5. The electrolyte circulation type battery according to claim 4, wherein the first opening / closing means control unit closes the recovery passage through the first opening / closing means when the circulation pump is activated.   6. The electrolyte flow type battery according to claim 1, further comprising a second opening / closing means for opening and closing the outward piping.   The electrolyte flow type battery according to claim 6, wherein the second opening / closing means is a valve. The second opening / closing means is an automatic valve;
A second opening / closing means controller for controlling the second opening / closing means;
The electrolyte flow type battery according to claim 6 or 7, wherein the second opening / closing means control section closes the outward piping via the second opening / closing means when the circulation pump stops.   9. The electrolyte flow type battery according to claim 8, wherein the second opening / closing means control unit opens the forward piping through the second opening / closing means when the circulation pump is activated. Each of the first opening / closing means and the second opening / closing means is an automatic valve,
A control means having a first opening / closing means control section for controlling the first opening / closing means and a second opening / closing means control section for controlling the second opening / closing means;
The control means includes
When the circulation pump is stopped, the second opening / closing means control unit closes the outward piping via the second opening / closing means, and the first opening / closing means control unit passes the first opening / closing means to the recovery. Open the passage,
When the circulating pump is activated, the first opening / closing means control unit closes the recovery passage via the first opening / closing means, and the second opening / closing means control unit passes the second opening / closing means to the forward path. 8. The electrolyte flow type battery according to claim 6 or 7, wherein piping is opened. A high position portion disposed at a position higher than the liquid level of the electrolytic solution in the electrolytic solution tank is provided in the outward piping,
The gas phase part in the said electrolyte tank and the said high position part are connected, The 1st gas phase piping for moving the gas phase in the said electrolyte tank to the said high position part is provided, It is characterized by the above-mentioned. Item 11. The electrolyte flow type battery according to any one of Items 1 to 10. A return pipe for communicating the recovery space and the electrolyte tank, and for returning the electrolyte in the recovery space to the electrolyte tank;
The electrolysis according to any one of claims 1 to 11, further comprising: a liquid feed pump for feeding the electrolytic solution in the recovery space to the electrolytic solution tank through the return pipe. Liquid-flow battery.   The electrolyte flow type battery according to claim 12, wherein the liquid feeding pump is an electric pump or an air pump. Has a secondary battery or uninterruptible power supply,
The electrolyte flow type battery according to claim 12 or 13, wherein electric power is supplied from the secondary battery or the uninterruptible power supply to the liquid feeding pump.   The electrolyte flow type battery according to claim 12 or 13, wherein electric power is supplied from the battery cell to the liquid feeding pump.   2. A second gas-phase pipe is provided for communicating the gas phase portion in the electrolyte tank and the recovery space, and for moving the gas phase in the electrolyte tank to the recovery space. Item 16. The electrolyte flow type battery according to any one of Items 12 to 15. A liquid amount detecting means for detecting the amount of the electrolytic solution in the recovery space;
A liquid feed pump control unit for controlling the liquid feed pump,
When the liquid amount detecting means detects that the amount of the electrolytic solution in the recovery space portion exceeds a predetermined upper limit, the liquid feed pump control unit activates the liquid feed pump, and the liquid feed pump The pump starts the liquid feeding, and the electrolyte solution flow type battery according to any one of claims 12 to 16.   When the liquid amount detecting means detects that the amount of the electrolytic solution in the recovery space portion is equal to or lower than a predetermined lower limit, the liquid supply pump control unit stops the liquid supply pump, and the liquid supply pump The electrolyte flow type battery according to claim 17, wherein the pump stops liquid feeding. The liquid feed pump control unit has a timer,
When the timer detects that a predetermined time has elapsed since the start of the liquid feeding pump, the liquid feeding pump control unit stops the liquid feeding pump, and the liquid feeding pump stops liquid feeding. The electrolyte solution type battery according to claim 17.   In the event of a power failure, the second opening / closing means is activated to open the forward piping, and the electrolytic solution is supplied from the electrolytic solution tank to the battery cell, whereby electric power is supplied from the battery cell to the circulation pump. The electrolyte flow type battery according to any one of claims 6 to 10.   It is a redox flow battery, The electrolyte flow type battery as described in any one of Claims 1-20 characterized by the above-mentioned.

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