WO2019030817A1

WO2019030817A1 - Redox flow battery and method for operating redox flow battery

Info

Publication number: WO2019030817A1
Application number: PCT/JP2017/028735
Authority: WO
Inventors: 桑原　雅裕
Original assignee: 住友電気工業株式会社
Priority date: 2017-08-08
Filing date: 2017-08-08
Publication date: 2019-02-14

Abstract

This redox flow battery is provided with: a positive electrode; a negative electrode; and a cell frame that includes a bipolar plate, on which the positive electrode and/or the negative electrode is disposed, and a frame body that is provided at a peripheral portion of the bipolar plate. The planar area of the frame body is 0.3 to 5 times the planar area of the electrode.

Description

[Repletion based on rule 26 25.08.2017] Redox flow battery, and operating method of redox flow battery

[Correction based on rule 91 25.08.2017]
The present invention relates to a redox flow battery and a method of operating a redox flow battery.

One of the storage batteries is a redox flow battery (hereinafter sometimes referred to as an RF battery) in which a battery reaction is performed by supplying an electrolytic solution to an electrode. As described in Patent Document 1, an RF battery includes a positive electrode supplied with a positive electrode electrolyte, a negative electrode supplied with a negative electrode electrolyte, and a diaphragm (ion exchange membrane) interposed between both electrodes. A battery cell comprising the An RF battery is typically used in a form called a cell stack in which a plurality of battery cells are stacked (FIG. 1, FIG. 7, etc. in Patent Document 1).

One battery cell is constructed by sandwiching the above-described main element by a cell frame including a bipolar plate and a frame provided on the peripheral portion of the bipolar plate (FIG. 7 of Patent Document 1). Each electrode is disposed on the bipolar plate of each cell frame. The cell stack is a laminated body in which cell frames sandwiching the above-mentioned main element (the same) is stacked, and a positive electrode forming one battery cell sandwiching a bipolar plate of one cell frame and another battery cell A negative electrode to be formed is disposed. That is, the cell stack includes a plurality of stacked combinations of the positive electrode, the cell frame, and the negative electrode. The laminate is clamped in the lamination direction of the laminate by a plurality of clamping shafts and nuts ([0005] in Patent Document 1).

JP, 2012-099368, A

The redox flow battery of the present disclosure is
A positive electrode,
A negative electrode,
And a cell frame including a bipolar plate on which at least one of the positive electrode and the negative electrode is disposed, and a frame provided on a peripheral portion of the bipolar plate.
The plane area of the frame is not less than 0.3 times and not more than 5 times the plane area of the electrode.

The operating method of the redox flow battery of the present disclosure is
The above-mentioned redox flow battery of the present disclosure is operated by supplying an electrolytic solution at a hydraulic pressure of 0.05 MPa or more.

It is a schematic plan view which shows the cell frame and electrode with which the redox flow battery of embodiment is equipped. It is an exploded perspective view showing a battery cell provided in a redox flow battery of an embodiment, and a schematic perspective view showing a cell stack. It is an operation principle figure of the redox flow battery of an embodiment. It is a schematic block diagram which shows the redox flow battery of embodiment provided with a cell stack.

[Problems to be solved by the present disclosure]
A redox flow battery (RF battery) in which the frame is not easily damaged is desired. In particular, it is desirable that the frame is not easily damaged even if the flow rate of the electrolyte solution is increased.

Here, during the operation of the RF battery, the fluid pressure acts on the flowing part of the electrolytic solution such as the above-mentioned electrode and the frame of the cell frame. The tightening force by the above-mentioned tightening shaft and nut is adjusted according to this hydraulic pressure. Assuming that the clamping force is W, the hydraulic pressure is Pl, the plane area of the frame of the cell frame is Sf, the plane area of the electrode is Sw, and the surface pressure of the frame is Pf, the clamping force W is expressed.
(Formula) W ≒ Pl × (Sf + Sw) + Pf × Sf

When the flow of the electrolyte is stopped at the time of standby of the RF battery, the clamping force W acts substantially only on the frame. The surface pressure Pfs of the frame at this time is larger than the surface pressure Pf during the flow of the electrolyte (Pf <Pfs). The frame is typically made of a resin excellent in acid resistance, such as polyvinyl chloride, for example, because it contacts an acidic electrolytic solution, but the resin frame may be damaged if it receives a large surface pressure Pfs. is there. In particular, when the fluid pressure Pl is also increased in order to increase the flow rate of the electrolyte, it is necessary to increase the clamping force W (see the above equation). As a result, the surface pressure Pfs described above becomes larger, and there is a concern that the frame may be damaged. Accordingly, there is a limit to the increase in the flow rate (liquid pressure) of the electrolyte, and an RF battery that can be handled by the demand for the increase in the flow rate of the electrolyte is desired. If the flow rate of the electrolyte solution is increased, the battery performance can be improved, or a large capacity battery provided with a larger electrode or cell stack can be formed, and thus there is the above-mentioned demand.

If the holding member for holding the distance between the end plates described in Patent Document 1 is provided, the surface pressure acting on the frame can be reduced, but the number of parts is increased.

An object of the present disclosure is to provide a redox flow battery in which the frame is not easily damaged. Another object of the present disclosure is to provide a method of operating a redox flow battery in which the frame is not easily damaged.

[Effect of the present disclosure]
According to the redox flow battery of the present disclosure and the operating method of the redox flow battery of the present disclosure, the frame is less likely to be damaged.

Description of an embodiment of the present invention
First, embodiments of the present invention will be listed and described.
(1) A redox flow battery (RF battery) according to one aspect of the present invention is
A positive electrode,
A negative electrode,
And a cell frame including a bipolar plate on which at least one of the positive electrode and the negative electrode is disposed, and a frame provided on a peripheral portion of the bipolar plate.
The plane area of the frame is not less than 0.3 times and not more than 5 times the plane area of the electrode.
"The plane area of the frame is 0.3 times to 5 times the plane area of the electrode" means that the plane area of the frame on the side where the positive electrode is arranged in the cell frame is the plane of the positive electrode 0.3 to 5 times the area, and the plane area of the frame on the side where the negative electrode is disposed in the cell frame is 0.3 to 5 times the planar area of the negative electrode, Meet at least one of the

In the above-described RF battery, the plane area of the frame satisfies the above-described specific ratio range with respect to the plane area of the electrode, so the flow rate of the electrolyte is high and the liquid pressure is large due to the following reasons. The frame is hard to break.

From the above (formula), the surface pressure Pfs when the flow of the electrolytic solution is stopped is expressed as Pfs = Pl + Pf + Pl × (Sw / Sf). From this equation, the smaller the Sw / Sf, that is, the larger the planar area Sf of the frame is with respect to the planar area Sw of the electrode, the smaller the surface pressure Pfs can be. If the plane area Sf of the frame is 0.3 times or more the plane area Sw of the electrode, it can be said that the frame is larger than the electrode. As a result, the surface pressure Pfs can be reduced, and the frame is less likely to be damaged even if the surface pressure Pfs acts. The above-described RF battery can increase the flow rate of the electrolytic solution while suppressing the breakage of the frame, so that the battery performance can be improved, or a large-capacity battery provided with a large electrode and a cell stack can be obtained.

Moreover, if the plane area Sf of the frame is not more than 5 times the plane area Sw of the electrode, the frame is not too large, and dimensional errors of the frame can be easily reduced. Here, in the case where the cell stack is provided ((4) described later), if the dimensional error of the frame is large, the positive electrode disposed on one surface of the bipolar plate provided in one cell frame and the negative electrode disposed on the other surface The relative positional deviation with the electrode tends to be large. On the other hand, if the dimensional error of the frame is small, it is easy to make the above positional deviation small, and thus it is easy to secure a large effective area of the battery reaction, and it is possible to suppress the deterioration of the battery performance due to the dimensional error. Further, as described above, since resins such as polyvinyl chloride generally have low thermal conductivity, the resin frame can not efficiently transfer the heat from the electrolyte stored in the frame to the outside. It can lead to temperature rise. As the temperature rises, precipitates are generated in the electrolytic solution, which causes deterioration of the electrolytic solution, resulting in deterioration of the battery performance. As described above, when the frame is not too large, the heat from the electrolytic solution is easily released to the outside of the frame, and the temperature rise is easily reduced. Therefore, deterioration of the electrolyte solution accompanying temperature rise can be prevented, and the fall of the battery performance resulting from the said temperature rise can be suppressed. By reducing the temperature rise, it is easy to reduce the temperature difference between the inside and the outside of the frame, so it is possible to reduce the breakage of the frame due to the thermal expansion difference of the frame based on the temperature difference.

(2) As an example of the above-mentioned RF battery
The planar shape of the electrode and the planar shape of the outer edge of the frame are rectangular,
The length of the long side of the outer edge of the frame is not more than three times the length of the long side of the electrode,
A mode in which the length of the short side of the outer edge of the frame is equal to or less than three times the length of the short side of the electrode may be mentioned.

In the above embodiment, the frame is not easily broken as described above, and the outer size of the frame satisfies the above-described specific range, so the frame is not too large, and the dimensional error of the frame is reduced. It is easy to obtain effects such as reduction of the reduction of the weight and reduction of the total weight.

(3) As an example of the above-mentioned RF battery
Planar area of the electrode include the embodiment is 500 cm ² or more 7000 cm ² or less.

The above embodiment is a large capacity battery provided with a large electrode, and the frame is not easily broken even if the flow rate of the electrolyte is increased. Further, in the above embodiment, since the planar area of the electrode satisfies the above-mentioned specific range, the size of the electrode and the frame is not too large, and the dimensional error of the frame described above is reduced, the battery performance is reduced, the total weight is reduced It is easy to get the effect. When the cell stack is provided, in addition to the frame, the dimensional error of the electrode can be reduced, so that the effective area of the cell reaction can be easily secured further.

(4) As an example of the above RF battery,
The positive electrode is disposed on one surface of the bipolar plate, and the negative electrode is disposed on the other surface,
The form provided with the cell stack which contains multiple lamination | stacking sets of the said positive electrode, the said cell frame, and the said negative electrode is mentioned.

Not only a single cell battery but also a multi-cell battery as in the above embodiment, the frame is not easily damaged even if the flow rate of the electrolyte is large and the liquid pressure is large.

(5) As an example of the above RF battery,
The liquid pressure of the electrolytic solution may be 0.05 MPa or more.
Here, the liquid pressure of the electrolytic solution may be a pressure by a pump used to supply the electrolytic solution to the electrode.

In the above embodiment, the clamping force W is also increased according to the hydraulic pressure at the time of operation, so the surface pressure Pfs at the time of stopping the flow of the electrolyte is likely to be larger, but the frame is less likely to be damaged. In the above embodiment, the liquid pressure at the time of operation is as large as 0.05 MPa or more, and the flow rate of the electrolyte is easily increased. Therefore, the battery performance is improved, or the capacity is increased by providing larger electrodes and cell stacks. be able to.

(6) As an example of the above RF battery,
The plane area of the frame body may be 0.6 to 2 times the plane area of the electrode.

In the above embodiment, since the frame satisfies the above-mentioned specific ratio range, the frame is less likely to be damaged even if the flow rate of the electrolyte is large and the fluid pressure is large. Moreover, since the said form is easy to make the dimensional error of a frame smaller, it is easy to reduce also the fall of battery performance.

(7) A method of operating a redox flow battery (RF battery) according to one aspect of the present invention,
The electrolytic solution is supplied to the RF battery described in any one of the above (1) to (6) at a hydraulic pressure of 0.05 MPa or more to operate.
Here, the fluid pressure includes the pressure by the pump used to supply the electrolyte to the electrode.

According to the above-described method of operating the RF battery, the clamping force W is increased according to the hydraulic pressure during operation, so the surface pressure Pfs at the time of suspension of the electrolytic solution tends to be larger, but the frame In order to satisfy a specific ratio range, the frame is hard to break. Further, in the above-described method of operating the RF battery, the liquid pressure at the time of operation is as large as 0.05 MPa or more, and the flow rate of the electrolyte is easily increased. Therefore, the battery performance is improved, or a large electrode or cell stack is provided. It can be applied to a capacity battery.

[Details of the Embodiment of the Present Invention]
Embodiments of the present invention will be specifically described below with reference to the drawings. In the figures, the same reference numerals indicate the same names.

[Embodiment]
First, an overview of the redox flow battery (RF battery) 10 of the embodiment will be mainly described with reference to FIGS. 2 to 4, and then details of the electrode 13 and the frame 22 will be described mainly with reference to FIG. Do. After that, the operation method of the RF battery of the embodiment will be described.
The ions shown in the positive electrode tank 16 and the negative electrode tank 17 of FIGS. 3 and 4 show examples of ion species contained in the electrolyte solution of each electrode. In FIG. 3, solid arrows indicate charging, and dashed arrows indicate discharging.

(Overview of RF battery)
As shown in FIG. 3, the RF battery 10 according to the embodiment includes a battery cell 10C and a circulation mechanism that circulates and supplies an electrolytic solution to the battery cell 10C. Typically, RF battery 10 is connected to power generation unit 420 and load 440 such as a power system or a customer via AC / DC converter 400 or transformation facility 410 to supply power generation unit 420. It charges as a source and discharges the load 440 as a power supply target. Examples of the power generation unit 420 include a solar power generator, a wind power generator, and other general power plants.

<Battery cell>
The battery cell 10C includes a positive electrode 14 to which a positive electrode electrolyte is supplied, a negative electrode 15 to which a negative electrode electrolyte is supplied, and a diaphragm 11 interposed between the positive electrode 14 and the negative electrode 15.
The positive electrode 14 and the negative electrode 15 are reaction sites to which an electrolytic solution containing an active material is supplied to cause a battery reaction of the active material (ion), and a porous material such as a fiber aggregate of a carbon material is used.
The diaphragm 11 is a member that separates the positive electrode 14 and the negative electrode 15 from each other and transmits a predetermined ion, and an ion exchange membrane or the like is used.

<Cell frame>
The battery cell 10C further includes a cell frame 20 illustrated in FIG. 2 and is constructed using the cell frame 20.

The cell frame 20 includes a bipolar plate 21 and a frame 22 provided on the periphery of the bipolar plate 21.

In the bipolar plate 21, at least one of the positive electrode 14 and the negative electrode 15 is disposed. In the bipolar plate 21 of the cell frame 20 included in the cell stack 30 described later, typically, the positive electrode 14 is disposed on one surface, and the negative electrode 15 is disposed on the other surface. The bipolar plate 21 is a conductive member which allows current to flow but does not allow the electrolyte solution to pass therethrough, and a conductive plastic plate or the like containing graphite and the like and an organic material is used.

The frame 22 includes a window 22w. The bipolar plate 21 and the electrode 13 are disposed inside the window 22w. The frame 22 is an insulating member provided with a supply path for supplying the electrolytic solution to the electrode 13 and a discharge path for discharging the electrolytic solution from the electrode 13. In FIG. 2, the case where the positive electrode supply passage and the positive electrode discharge passage are provided on one surface side of the frame 22 and the negative electrode supply passage and the negative electrode discharge passage are provided on the other surface side of the frame 22 is illustrated. The positive electrode supply passage and the negative electrode supply passage have

liquid supply holes

24i and 25i, and

slits

26i and 27i extending from the

liquid supply holes

24i and 25i to the window 22w. The positive electrode discharge path and the negative electrode supply path include drainage holes 24o and 25o, and slits 26o and 27o extending from the window 22w to the drainage holes 24o and 25o. Each of the

holes

24 i, 24 o, 25 i, 25 o is a through hole penetrating the front and back of the frame 22. The slits 26 i and 26 o on the positive electrode side are provided on one surface of the frame 22. The slits 27 i and 27 o on the negative electrode side are provided on the other surface of the frame 22. In the cell stack 30, the plurality of cell frames 20 are stacked, whereby the

liquid supply holes

24i and 25i and the drain holes 24o and 25o respectively form a flow channel of the electrolytic solution.

The frame 22 of this example surrounds the window 22w, and the seal groove 28 (FIG. 2, FIG. 4) is fitted on the outer edge 22o side of the

liquid supply holes

24i, 25i and the drain holes 24o, 25o. Fig. 1) is provided. The sealing material 18 interposed between the frames 22 and 22 (FIG. 4) maintains the spaces between the

frames

22 and 22 in a liquid tight manner. During the flow of the electrolytic solution, the fluid pressure acts on the area of the frame 22 mainly surrounded by the annular seal material 18.

The constituent material of the frame 22 is excellent in insulation, does not react with the electrolytic solution, and can be suitably used as having resistance (chemical resistance, acid resistance, etc.) to the electrolytic solution. Specific constituent materials include vinyl chloride, polyethylene, polypropylene and the like.

<Cell stack>
The RF battery 10 can be a multi-cell battery including a plurality of battery cells 10C in addition to a single cell battery (FIG. 3) including a single battery cell 10C. In a multi-cell battery, a form called a cell stack 30 shown in FIGS. 2 and 4 is used.

The cell stack 30 mainly includes a stacked body in which a plurality of cell frames 20 (bipolar plates 21), a positive electrode 14, a diaphragm 11, and a negative electrode 15 are sequentially stacked. Such a cell stack 30 includes a plurality of stacked sets of the positive electrode 14, the cell frame 20 (bipolar plate 21), and the negative electrode 15 (FIG. 4). Typically, the cell stack 30 includes the above laminate, a pair of

end plates

32 and 32 sandwiching the laminate, and a fastening member 33 such as a fastening shaft 33 such as a long bolt connecting the

end plates

32 and 32 and a nut. (Figure 2). When the

end plates

32, 32 are tightened by the fastening members, the stack is held in the stacked state by the tightening force in the stacking direction.

The cell stack 30 may have a predetermined number of battery cells 10C as a sub-cell stack, and may have a form in which a plurality of sub-cell stacks are stacked. The subcell stack can include an electrolyte supply / discharge plate portion. FIG. 2 exemplifies a case where a plurality of subcell stacks including a supply and discharge plate portion are provided. In the cell frames located at both ends in the stacking direction of the battery cells 10C in the subcell stack and the cell stack 30, a bipolar plate 21 may be used or one in which a current collector plate made of metal or the like may be arranged together with the bipolar plate 21. . The number of battery cells 10C provided in the cell stack 30 may be appropriately selected.

<Circulation mechanism>
As shown in FIG. 3 and FIG. 4, the circulation mechanism includes a positive electrode tank 16 for storing positive electrode electrolyte to be supplied to the positive electrode 14, a negative electrode tank 17 for storing negative electrode electrolyte to be supplied to the negative electrode 15, and a positive electrode.

Pipings

162 and 164 connecting between the tank 16 and the battery cell 10C (cell stack 30),

Pipings

172 and 174 connecting between the negative electrode tank 17 and the battery cell 10C (cell stack 30), and supply side to the battery cell 10C And pumps 160 and 170 provided in the

pipings

162 and 172 of FIG. The

pipes

162, 164, 172 and 174 are connected to the above-mentioned

liquid supply holes

24i and 25i and the liquid discharge holes 24o and 25o, respectively (in the cell stack 30, the above-mentioned flow line is connected), Build a fluid circulation pathway.

For the basic configuration, materials, electrolyte solution and the like of the RF battery 10, known configurations, materials, electrolyte solution and the like can be appropriately used. For example, electrolytes other than the vanadium-based electrolytes illustrated in FIGS. 3 and 4 can be used.

(Details of electrode and frame)
In the RF battery 10 of the embodiment, the plane area of the frame 22 provided in the cell frame 20 satisfies a specific ratio range with respect to the plane area of the electrode 13. Specifically, the planar area of the frame 22 is 0.3 times to 5 times the planar area of the electrode 13. In the unit cell battery, the planar area of the frame 22 of the cell frame 20 on the positive electrode side is 0.3 times to 5 times the planar area of the positive electrode 14, and the frame 22 of the cell frame 20 on the negative electrode side. At least one of the planar area being 0.3 to 5 times the planar area of the negative electrode 15 is satisfied. It is preferable to satisfy both. In the multi-cell battery provided with the cell stack 30, the plane area of the frame 22 on the side where the positive electrode 14 is disposed in any cell frame 20 excluding both ends in the stacking direction is 0.3 or more times the planar area of the positive electrode 14 At least five times, and at least the plane area of the frame 22 on the side of the cell frame 20 on which the negative electrode 15 is disposed is 0.3 times to 5 times the plane area of the negative electrode 15; Meet one. It is preferable to satisfy both. Other than the form in which the planar area of the positive electrode 14 and the planar area of the negative electrode 15 are equal, different forms can be adopted. In any form, at least one of the positive electrode side and the negative electrode side of the frame 22 provided in the arbitrary cell frame 20 as described above, preferably, the planar area of both is 0.3 to 5 times the planar area of the electrode 13 The following should be satisfied. In addition, if the specific ratio range is satisfied, the ratio to the planar area of the electrode 13 on one surface side and the other surface side (positive electrode side, negative electrode side) of the frame 22 may be equal or different.

(electrode)
The electrode 13 can be made into the RF battery 10 with a large capacity as the planar area Sw is larger, and if it is small to some extent, dimensional error (manufacturing error) can be easily reduced and a large effective area of battery reaction can be easily secured. It is possible to reduce the decrease in battery performance due to dimensional error. Further, the frame 22 is not enlarged due to the electrode 13, and the heat dissipation is reduced due to the upsizing of the frame 22, the deterioration of the electrolyte solution resulting therefrom, and the reduction of the battery performance are reduced. It is possible to reduce the breakage of the frame 22 due to the thermal expansion difference caused by the temperature difference between inside and outside. Furthermore, the total weight of the battery cell 10C and the cell stack 30 can be reduced. As planar area Sw of the electrode 13 to achieve these effects include 500 cm ² or more 7000 cm ² or less. Planar area Sw is 550 cm ² or more, further 600 cm ² or more, 800 cm ² above, with the 1000 cm ² or more, may be further a large capacity battery. Even if the RF battery 10 of the embodiment is such a large capacity battery, the size of the frame 22 is a specific size as described above and is not easily broken. I can drive by enlarging it. Planar area Sw is 6000 cm ² or less, further 5000 cm ² or less, if it is 4000 cm ² or less, reduction of the above-mentioned dimensional errors, decrease a reduction in battery performance, more easily achieving effects such as total weight reduction. Planar area Sw is 3800 cm ² or less, further 3300 cm ² or less, if it is 2800 cm ² or less, further easily obtained effects such as the reduction of the dimensional error.

The planar shape of the electrode 13 in this example is rectangular. In addition, examples of the planar shape of the electrode 13 include curved shapes such as a circle and an ellipse, and polygonal shapes such as a hexagon. If the planar shape of the electrode 13 is rectangular as in this example, it is easier to uniformly flow the electrolytic solution over the entire plane of the electrode 13 compared to the other shapes described above, and a region in which the cell reaction can be performed uniformly. It is easy to secure

In the rectangular electrode 13, the length L _{13 of} the long side and the length H ₁₃ of the short side (FIG. 1) can be appropriately selected as long as the planar area Sw described above is satisfied. The rectangle also includes a square.

(Frame)
The larger the planar area Sf of the frame body 22 is, the smaller the surface pressure Pfs (= Pl + Pf + Pl × (Sw / Sf)) that acts when the flow of the electrolytic solution is stopped. In particular, if the plane area Sf of the frame 22 is larger, the Sw / Sf is likely to be smaller, and the surface pressure Pfs is more likely to be smaller. As the surface pressure Pfs is smaller, the frame 22 can be made more resistant to breakage. Therefore, in the RF battery 10 of the embodiment, the ratio range of the plane area Sf of the frame 22 to the plane area Sw of the electrode 13 is set as a specific range (0.3 times or more and 5 times or less).

If the plane area Sf of the frame 22 is 0.3 or more times the plane area Sw of the electrode 13 (0.3 × Sw ≦ Sf), the surface pressure Pfs can be easily reduced, and the frame 22 is less likely to be broken. When the plane area Sf of the frame 22 is 0.4 times or more, and further 0.6 times or more of the plane area Sw of the electrode 13, the frame 22 is less likely to be broken. Here, in the case where the plane area Sf of the frame 22 is 0.3 times the plane area Sw of the electrode 13, the surface pressure acting on the frame 22 at the time of suspension of the electrolytic solution is the surface at the time of the electrolytic solution Approximately 4.3 times the pressure. That is, if the plane area Sf of the frame 22 is 0.3 times or more of the plane area Sw of the electrode 13, fluctuations in the surface pressure acting on the frame 22 at the time of circulation and at the time of suspension of the electrolyte It can be in the range of about 4.3 times or less of the surface pressure. As a result, it is possible to reduce problems due to surface pressure fluctuations. From the viewpoint of reducing the fluctuation of the surface pressure, the plane area Sf of the frame 22 can be 0.7 times or more, and further 0.9 times or more the plane area Sw of the electrode 13.

If the plane area Sf of the frame 22 is not more than five times the plane area Sw of the electrode 13 (Sf ≦ 5 × Sw), the frame 22 is not too large, and the occupancy of the electrode 13 in the battery cell 10C or the cell stack 30 To make it possible to secure a large area for battery reaction. Moreover, the dimensional error (manufacturing error) of the frame 22 can be easily reduced by not making the frame 22 too large. When the cell stack 30 is provided, the relative positional deviation between the positive electrode 14 on one surface side of the bipolar plate 21 and the negative electrode 15 on the other surface side can be easily reduced because the dimensional error is small. As a result, it is easy to ensure a large effective area of the cell reaction, and it is possible to reduce the deterioration of the cell performance due to the above-mentioned dimensional error. Furthermore, since the frame 22 is not too large, heat from the electrolyte stored in the frame 22 is easily released to the outside of the frame 22, and the temperature rise is easily reduced, so that the electrolyte is deteriorated with the temperature rise. Can be prevented, and the decrease in battery performance due to the temperature rise can be reduced. In addition, since the temperature rise is reduced, the temperature difference between the inside and outside of the frame 22 can be easily reduced, and the breakage of the frame 22 due to the difference in thermal expansion of the frame 22 caused by the temperature difference can also be reduced. The total weight of the battery cell 10C and the cell stack 30 can also be reduced. As the planar area Sf of the frame 22 is smaller than or equal to 4.5 times and further 4 times or less of the planar area Sw of the electrode 13, the above-described effects are more easily obtained. The plane area Sf of the frame 22 is not more than three times and not more than two times the plane area Sw of the electrode 13 in view of the improvement of the occupancy rate, the reduction of dimensional error, the reduction of battery performance and the reduction of total weight. , 1.8 times or less.

Planar area Sf of the frame body 22 satisfies 0.3 × Sw ≦ Sf ≦ 5 × Sw, further, the planar area Sw of the electrode 13 meets the 500 cm ² or more 7000 cm ² or less ^{^{(150cm 2 ≦ Sf ≦ 35000cm 2}} ), It is possible to make the RF battery 10 in which the frame 22 is less likely to be broken even if the flow rate (liquid pressure) of the electrolyte solution is increased with a large capacity. Further, in this case, it is easier to obtain the effects such as the improvement of the occupancy rate, the reduction of the dimensional error, the reduction of the battery performance, and the reduction of the total weight. When meeting the 0.6 × Sw ≦ Sf ≦ 2 × Sw and 500cm ^² ≦ Sw ≦ 4000cm ^2, it is possible to frame 22 by increasing the flow rate of the electrolytic solution is the difficult RF battery 10 more cracking.

The planar shape of the outer edge 22 o of the frame 22 in this example is rectangular. In addition, as the planar shape of the outer edge 22 o of the frame 22, a curved shape such as a circle or an ellipse, or a polygonal shape such as a hexagon may be mentioned. If the planar shape of the outer edge 22 o is rectangular as in this example, the battery cell 10 C and the cell stack 30 can be formed into a rectangular shape, which is easier to handle than the other shapes described above.

The outer size and the inner size of the frame 22 can be appropriately selected as long as the planar area Sf described above is satisfied. When the planar shape of the electrode 13 and the planar shape of the outer edge 22 o of the frame 22 are rectangular as in this example, the long side length Lo of the outer edge 22 o of the frame 22 is the length L of the long side of the electrode 13. 3 times ₁₃ or less, the length Ho of the short side of the outer edge 22o of the frame 22 include be less three times the short side length _{H 13} of the electrode 13 (Sf ≦ 8 × Sw) . Since the outer size (Lo, Ho) of the frame 22 is not more than three times the lengths L ₁₃ and H ₁₃ of the electrodes 13, the frame 22 is not too large, and the above-mentioned occupancy ratio is improved and the dimensional error is reduced. It is easier to obtain effects such as (increase of effective area of battery reaction), suppression of decrease in battery performance, and reduction of total weight. From the viewpoint of these effects, the length Lo of the long side of the frame 22 is 2.8 times or less or 2.5 times or less the length L ₁₃ of the long side of the electrode 13 or the short side of the frame 22 The length Ho of the electrode 13 can be 2.8 times or less, or 2.5 times or less the length H ₁₃ of the short side of the electrode 13.

Typically, the planar shape of the window 22 w (inner edge) of the frame 22 may be a shape corresponding to the outer shape of the electrode 13. The planar shape of the window 22w in this example is rectangular, and the long side length Li of the window 22w corresponds to the long side length L ₁₃ of the electrode 13 so that the rectangular electrode 13 can be disposed. The length Hi of the short side of the portion 22 w is adjusted in accordance with the length H ₁₃ of the short side of the electrode 13.

(Operating conditions of RF battery)
In the RF battery 10 of the embodiment in which the plane area Sf of the frame 22 satisfies 0.3 × Sw ≦ Sf ≦ 5 × Sw, the frame 22 is unlikely to be broken even if the fluid pressure is increased to some extent. Therefore, the RF battery 10 according to the embodiment can increase the liquid pressure of the electrolyte during operation to 0.05 MPa or more. Although the clamping force W is increased according to the liquid pressure, the plane area Sf of the frame 22 satisfies the specific ratio range described above, so the surface pressure Pfs acting on the frame 22 when the flow of the electrolyte is stopped is reduced. It is easy to do so and the frame 22 is hard to break. In addition, if the liquid pressure of the electrolytic solution during operation is set to 0.05 MPa or more, the flow rate of the electrolytic solution can be increased, the battery performance can be improved, or a large capacity battery equipped with a larger electrode or a large capacity equipped with the cell stack 30 It can be used as a battery. From the viewpoint of improving the battery performance, increasing the capacity, etc., the liquid pressure can be increased to 0.1 MPa or more, further 0.2 MPa or more, 0.3 MPa or more.

The larger the fluid pressure, the easier it is to improve the battery performance. However, if it is too large, the clamping force W becomes too large and the frame 22 may be cracked. When the liquid pressure is about 0.5 MPa or less, the frame 22 can be made more resistant to breakage.

(How to operate the RF battery)
In the method of operating the RF battery according to the embodiment, the electrolyte solution is applied to the RF battery 10 according to the embodiment at a hydraulic pressure of 0.05 MPa or more in the embodiment where the plane area Sf of the frame 22 satisfies 0.3 × Sw ≦ Sf ≦ 5 × Sw. Supply and drive. As described above, by increasing the fluid pressure to 0.05 MPa or more, the battery performance can be improved, or the battery can be applied to a large capacity battery. For the range of fluid pressure, refer to the above-mentioned section of the operating condition of the RF battery.

In addition, the pressure by the pump 160,170 is mentioned for the liquid pressure of the electrolyte solution in the above-mentioned driving | running condition and a driving | running method. The outputs of the

pumps

160 and 170 may be adjusted so that the fluid pressure has a desired magnitude.

(Use)
The RF battery 10 according to the embodiment is a storage battery for the purpose of stabilizing the fluctuation of the power generation output, storing power when surplus of generated power, load leveling, etc. for power generation of natural energy such as solar power generation and wind power generation. Available. In addition, the RF battery 10 of the embodiment is juxtaposed to a general power plant, and can be used as a storage battery for the purpose of the countermeasure against the instantaneous drop / blackout and the load leveling. The operating method of the RF battery according to the embodiment can increase the flow rate of the electrolyte, and thus can be suitably used when it is desired that the flow rate is large.

(effect)
In the RF battery 10 of the embodiment, the plane area Sf of the frame 22 satisfies the above-described specific ratio range with respect to the plane area Sw of the electrode 13. Therefore, in the RF battery 10 of the embodiment, the surface pressure Pfs acting on the frame 22 can be reduced when the flow of the electrolyte is stopped, and the frame 22 is less likely to be damaged. Further, the RF battery 10 according to the embodiment can increase the flow rate of the electrolytic solution by increasing the fluid pressure while suppressing the breakage of the frame 22, so that the battery performance can be improved or a large capacity battery can be obtained. it can. When the RF battery 10 includes the cell stack 30, the frame 22 is damaged although the tightening force W is larger than that of the single cell battery and the surface pressure Pfs at the time of stopping the flow of the electrolyte tends to be larger. It is difficult to do.

The operating method of the RF battery according to the embodiment increases the clamping force W according to the hydraulic pressure during operation, so the surface pressure Pfs at the time of suspension of the electrolytic solution tends to be larger, but the above-mentioned specific ratio range In the RF battery 10 provided with the frame 22 satisfying the above, the frame 22 is hard to break. Further, in the above-described method of operating an RF battery, since the fluid pressure is large, the flow rate of the electrolyte can be easily increased, and the battery performance can be improved, or the battery can be applied to a large capacity battery.

The present invention is not limited to these exemplifications, is shown by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims.

10 redox flow battery (RF battery)
DESCRIPTION OF SYMBOLS 10C battery cell 11 diaphragm 13 electrode 14 positive electrode 15 negative electrode 16 positive electrode tank 17 negative electrode tank 160,170

pump

162, 164, 172, 174 Piping 18 seal material 20 cell frame 21 bipolar plate 22 frame 22 frame 22o outer edge 22

w window

24i, 25i Supply hole 24o,

25o Drain hole

26i, 26o, 27i, 27o Slit 28 Seal groove 30 Cell stack 32 End plate 33 Fastening shaft 400 AC / DC converter 410 Substation 420 Power generation unit 440 Load

Claims

A positive electrode,
A negative electrode,
And a cell frame including a bipolar plate on which at least one of the positive electrode and the negative electrode is disposed, and a frame provided on a peripheral portion of the bipolar plate.
The redox flow battery whose planar area of the said frame is 0.3 times or more and 5 times or less of the planar area of the said electrode.
The planar shape of the electrode and the planar shape of the outer edge of the frame are rectangular,
The length of the long side of the outer edge of the frame is not more than three times the length of the long side of the electrode,
The redox flow battery according to claim 1, wherein the length of the short side of the outer edge of the frame is not more than three times the length of the short side of the electrode.
Planar area of the electrode, the redox flow battery according to claim 1 or claim 2 is 500 cm 2 or more 7000 cm 2 or less.
The positive electrode is disposed on one surface of the bipolar plate, and the negative electrode is disposed on the other surface,
The redox flow battery according to any one of claims 1 to 3, comprising a cell stack including a plurality of stacked sets of the positive electrode, the cell frame, and the negative electrode.
The liquid pressure of electrolyte solution is 0.05 MPa or more, The redox flow battery of any one of Claim 1 to 4.
The redox flow battery according to any one of claims 1 to 5, wherein a plane area of the frame is 0.6 times or more and 2 times or less of a plane area of the electrode.
The method of operating a redox flow battery according to any one of claims 1 to 6, wherein the electrolytic solution is supplied at a hydraulic pressure of 0.05 MPa or more to operate the redox flow battery.