JP2017010791A - Cell frame, cell stack and redox flow cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cell frame capable of reducing an outer shape area of a frame body while maintaining an area of a recess formed inside of the frame body, a cell stack comprising the same, and a redox flow cell.SOLUTION: The cell frame comprises a frame body and a bipolar plate and inside of the frame body, a recess is formed for accommodating an electrode. The frame body includes: a liquid supply side piece including a liquid supply manifold and a liquid supply slit; and a liquid drain side piece including a liquid drain manifold and a liquid drain slit. In the cell frame, when a direction in which the liquid supply side piece and the liquid drain side piece oppose each other is defined as a longitudinal direction, a direction orthogonal to the longitudinal direction is defined as a lateral direction, a direction toward the inside of the frame body between the longitudinal direction and the lateral direction is defined as an inner side and an opposite direction is defined as an outer side, a position that is positioned at an innermost side in the longitudinal direction in at least one of the liquid supply manifold and the liquid drain manifold is positioned inside of a point that is positioned at an outermost side in the longitudinal direction in the recess.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cell frame and a cell stack, which are components of a redox flow battery, and a redox flow battery. In particular, the present invention relates to a cell frame that can reduce the outer area of the frame while maintaining the area of the recess formed inside the frame of the cell frame.

  As one of large-capacity storage batteries, redox flow batteries (hereinafter sometimes referred to as “RF batteries”) are known (see Patent Documents 1 to 3). Applications of redox flow batteries include load leveling applications, applications such as instantaneous voltage drop compensation and emergency power supplies, and smoothing of natural energy output such as solar power generation and wind power generation that are being introduced in large quantities. Can be mentioned.

  An RF battery is a battery that performs charge and discharge using an electrolytic solution containing a metal ion (active material) whose valence is changed by oxidation and reduction in a positive electrode electrolyte and a negative electrode electrolyte. FIG. 6 shows an operation principle diagram of a vanadium RF battery 300 using a vanadium electrolyte containing V ions as an active material of the positive electrode electrolyte and the negative electrode electrolyte. The solid line arrow in the battery cell 100 in FIG. 6 indicates a charging reaction, and the broken line arrow indicates a discharging reaction.

  The RF battery 300 includes a cell 100 separated into a positive electrode cell 102 and a negative electrode cell 103 by an ion exchange membrane 101 that transmits hydrogen ions. A positive electrode 104 is built in the positive electrode cell 102, and a positive electrode electrolyte solution tank 106 for storing the positive electrode electrolyte is connected via conduits 108 and 110. Similarly, a negative electrode 105 is built in the negative electrode cell 103, and a negative electrode electrolyte solution tank 107 for storing a negative electrode electrolyte is connected via conduits 109 and 111. Then, the electrolytes stored in the tanks 106 and 107 are circulated and circulated to the cell 100 (the positive electrode cell 102 and the negative electrode cell 103) by the pumps 112 and 113 to perform charging and discharging.

  The RF battery 300 normally uses a configuration including a cell stack in which a plurality of cells 100 are stacked. FIG. 7 is a schematic configuration diagram of a cell stack. A cell stack 10S illustrated in FIG. 7 is formed by stacking a plurality of cell frames 20, a positive electrode 104, an ion exchange membrane 101, and a negative electrode 105 each having a bipolar plate 21 provided inside a rectangular frame-shaped frame body 22. The laminate is sandwiched between two end plates 250 and 250 and tightened. In the cell frame 20, recesses 24 are formed on both inner surfaces of a frame 22 on which the bipolar plate 21 is provided, and electrodes (positive electrode 104 or negative electrode 105) having substantially the same size are accommodated in the recesses 24. Thereby, the space surrounded by the recess 24 formed by the frame body 22 and the bipolar plate 21 and the ion exchange membrane 101 constitutes a cell (positive electrode cell or negative electrode cell).

  In the cell stack 10S, the positive electrode 104 is disposed on one surface side of the bipolar plate 21, the negative electrode 105 is disposed on the other surface side, and an ion exchange membrane 101 is interposed between adjacent cell frames 20 to form one cell. Will be. The flow of the electrolyte in the cell stack 10S is formed between the manifold 200 provided through the frame body 22 and the surface of the frame body 22 and between the manifold 200 and the inside (recessed portion) of the frame body 22. The slit 210 is used. The cell frame 20 illustrated in FIG. 7 is a supply side piece in which one long piece (the lower long piece in FIG. 7) of the frame body 22 has liquid supply manifolds 201 and 202 and liquid supply slits 211 and 212. The other long piece (the upper long piece in FIG. 7) is a drainage side piece having drainage manifolds 203 and 204 and drainage slits 213 and 214. In the cell stack 10 </ b> S, the positive electrode electrolyte is supplied from the liquid supply manifold 201 to the recess 24 in which the positive electrode 104 is accommodated through a slit 211 formed on one surface side (paper surface side) of the liquid supply side piece of the frame body 22. Is done. Then, as shown by the arrows in FIG. 7, the inside of the recess 24 flows from the lower side to the upper side, and is discharged from the recess 24 to the drainage manifold 203 through the slit 213 formed in the drainage side piece of the frame 22. The Similarly, the negative electrode electrolyte is supplied from the liquid supply manifold 202 to a recess in which the negative electrode 105 is accommodated through a slit 212 formed on the other surface side (back side of the paper surface) of the liquid supply side piece of the frame body 22. . Then, it flows from the lower side to the upper side in the recess, and is discharged from the recess to the drainage manifold 204 via the slit 214 formed in the drainage side piece of the frame body 22. Between the cell frames 20, an annular seal member 25 such as an O-ring or a flat packing is disposed along the outer edge portion of the frame body 22 in order to suppress leakage of the electrolytic solution.

  In general, as shown in FIG. 8, in the conventional cell frame 20, the outer shape of the frame body 22 is rectangular, and the shape of the recess 24 of the frame body 22 is also the same rectangular shape. Usually, a liquid supply manifold 201 is provided below the lower end of the recess 24, and a drainage manifold 203 is provided above the upper end of the recess 24, so that the liquid supply manifold 201 and the drainage manifold 203 are diagonal. Formed in position. Although not shown in FIG. 8, the negative electrode electrolyte supply manifold and drain manifold are similarly formed at positions symmetrical to the positive electrode electrolyte supply manifold 201 and drain manifold 203. Yes.

  In addition, the ion exchange membrane 101 interposed between the cell frames 20 has a size such that the outer edge thereof is in contact with the seal member 25. The area of the ion exchange membrane 101 is the area of the cell frame 20 (frame body 22). Is substantially equal to the outer area of

JP 2013-80613 A JP 2002-246061 A JP 2005-228622 A

  In recent years, with the introduction of large-scale natural energy power generation, there is an increasing expectation for an RF battery that can store a large amount of electric power, and further downsizing and cost reduction of the RF battery are desired. .

  From the viewpoint of miniaturization of the RF battery, it is conceivable to reduce the size of the cell frame (frame body). However, when the size of the cell frame is simply reduced, the size of the recess formed inside the frame is also reduced, so the size of the electrode accommodated in the recess has to be reduced. If the electrode area is reduced, the output is reduced, which is not preferable. Therefore, it is required to reduce the area of the cell frame (outer area of the frame) while maintaining the area of the recess.

  Also, in order to ensure the mechanical strength of the frame, it is necessary to secure a margin (minimum distance from the opening edge of the recess or manifold to the outer periphery of the frame) in the part surrounding the recess or the peripheral part of the manifold. is there. As shown in FIG. 8, in the conventional cell frame 20, a liquid supply manifold 201 is provided below the lower end of the recess 24, and a drainage manifold 203 is provided above the upper end of the recess 24. Therefore, the height Fh of the cell frame 20 (frame body 22) needs to be at least the sum of the height Ch of the recess 24, the diameter Md of each manifold 201, 203, and the vertical margin mv. In the figure, Fw is the width of the cell frame 20 (frame body 22), Cw is the width of the recess 24, mc is the margin in the horizontal direction, and ev is the frame from the upper end (upper edge) or the lower end (lower edge) of the recess 24. This is the shortest vertical distance to the outer periphery of the body 22.

  Furthermore, from the viewpoint of cost reduction of the RF battery, it is desired to reduce the amount of use by reducing the size of the expensive ion exchange membrane. As described above, the size of the ion exchange membrane is substantially the same as the cell frame. Therefore, if the area of the cell frame can be reduced, the area of the ion exchange membrane can be reduced, so that the cost can be reduced. Become. However, conventionally, it has not been said that sufficient studies have been made to reduce the area of the cell frame while maintaining the area of the recess formed inside the frame.

  The present invention has been made in view of the above circumstances, and one of the objects of the present invention is to reduce the outer area of the frame while maintaining the area of the recess formed inside the frame of the cell frame. To provide a cell frame. Another object of the present invention is to provide a cell stack including the cell frame and a redox flow battery including the cell stack.

  A cell frame according to an aspect of the present invention includes a frame and a bipolar plate provided inside the frame, and an electrode is provided inside the frame by an inner peripheral surface of the frame and a surface of the bipolar plate. A recess is formed for storing the. The frame includes a liquid supply side piece and a drainage side piece provided to face the liquid supply side piece. The liquid supply side piece includes a liquid supply manifold through which an electrolytic solution supplied to the concave portion flows, and a liquid supply slit for supplying the electrolytic solution from the liquid supply manifold to the concave portion. The drainage side piece has a drainage manifold through which the electrolyte discharged from the recess flows, and a drainage slit for discharging the electrolyte from the recess to the drainage manifold. In the cell frame, a direction in which the liquid supply side piece and the liquid discharge side piece face each other is a vertical direction, a direction orthogonal to the vertical direction is a horizontal direction, and each direction of the vertical direction and the horizontal direction The direction toward the inside of the frame body is the inside, and the opposite direction is the outside. At this time, the point located on the innermost side in the vertical direction in at least one of the liquid supply manifold and the drainage manifold is located on the inner side than the point located on the outermost side in the vertical direction of the recess. .

  A cell stack according to one embodiment of the present invention is formed by stacking a plurality of cell frames according to one embodiment of the present invention, a positive electrode, an ion exchange membrane, and a negative electrode.

  A redox flow battery according to one embodiment of the present invention includes the cell stack according to one embodiment of the present invention.

  The cell frame can reduce the outer area of the frame while maintaining the area of the recess formed inside the frame. The cell stack and the redox flow battery can be reduced in size and cost.

3 is a schematic plan view showing a cell frame according to Embodiment 1. FIG. 6 is a schematic plan view showing a cell frame according to Embodiment 2. FIG. 6 is a schematic plan view showing a cell frame according to Embodiment 3. FIG. It is a schematic plan view which shows the modification of the cell frame which concerns on embodiment. It is a schematic plan view which compares and shows an implementation model and a comparison model. It is an operation | movement principle figure of a redox flow battery. It is a schematic block diagram of a cell stack. It is a schematic plan view which shows an example of the conventional cell frame.

[Description of Embodiment of the Present Invention]
The present inventors diligently studied to reduce the area of the cell frame (outer area of the frame) while maintaining the area of the recess formed inside the frame of the cell frame. As a result, the present inventors have found that the external area of the frame can be reduced while maintaining the area of the recess by satisfying a specific condition of the positional relationship between the manifold and the recess, and the present invention has been completed. Hereinafter, embodiments of the present invention will be listed and described.

  (1) The cell frame which concerns on 1 aspect of this invention is equipped with the frame and the bipolar plate provided inside the said frame, The inner peripheral surface of the said frame, and the surface of the said bipolar plate of the said frame A recess for accommodating the electrode is formed inside. The frame includes a liquid supply side piece and a drainage side piece provided to face the liquid supply side piece. The liquid supply side piece includes a liquid supply manifold through which an electrolytic solution supplied to the concave portion flows, and a liquid supply slit for supplying the electrolytic solution from the liquid supply manifold to the concave portion. The drainage side piece has a drainage manifold through which the electrolyte discharged from the recess flows, and a drainage slit for discharging the electrolyte from the recess to the drainage manifold. In the cell frame, a direction in which the liquid supply side piece and the liquid discharge side piece face each other is a vertical direction, a direction orthogonal to the vertical direction is a horizontal direction, and each direction of the vertical direction and the horizontal direction The direction toward the inside of the frame body is the inside, and the opposite direction is the outside. At this time, the point located on the innermost side in the vertical direction in at least one of the liquid supply manifold and the drainage manifold is located on the inner side than the point located on the outermost side in the vertical direction of the recess. .

  According to the above cell frame, the height of the frame can be reduced because the point located on the innermost side in the vertical direction of the manifold is located on the inner side of the point located on the outermost side in the vertical direction of the recess. The external area of the body can be reduced. In this case, when the height of the concave portion is the same as that of the conventional cell frame and the area of the concave portion is the same, the width of the concave portion becomes larger and the width of the frame body may be larger than the conventional one. The overall external dimensions can be reduced. Therefore, the cell frame can reduce the outer area of the frame while maintaining the area of the recess formed inside the frame. Therefore, it is possible to reduce the size while maintaining the electrode area and avoiding a decrease in output. Moreover, since the area of the cell frame is reduced, the area of the ion exchange membrane can be reduced correspondingly, and the cost can be reduced. Here, “height” refers to the length in the vertical direction, and “width” refers to the length in the horizontal direction.

  (2) As one form of the cell frame, a point located on the innermost side in the lateral direction in the at least one manifold may be located on an inner side than a point located on the outermost side in the lateral direction of the recess. Can be mentioned.

  According to the said form, the width | variety of a frame can be made small by the point located in the innermost side of the horizontal direction of a manifold being located inside the point located in the outermost side of the horizontal direction of a recessed part, and the area of a recessed part While maintaining the above, the outer area of the frame can be made smaller.

  (3) As one form of the cell frame, a point located on the outermost side in the vertical direction in the at least one manifold may be located on an inner side than a point located on the outermost side in the vertical direction of the recess. Can be mentioned.

  According to the above aspect, the height of the frame body can be further reduced because the point located on the outermost side in the vertical direction of the manifold is located on the inner side of the point located on the outermost side in the lateral direction of the recess. The outer area of the frame can be further reduced while maintaining the area.

  (4) A cell stack according to an aspect of the present invention includes a plurality of cell frames, positive electrodes, ion exchange membranes, and negative electrodes, each of which is any one of the above (1) to (3). Do it.

  According to the cell stack, since the cell frame according to one aspect of the present invention is provided, the area of the cell frame can be reduced while maintaining the area of the concave portion in which the electrode in the cell frame is stored. Therefore, it is possible to reduce the size while maintaining the electrode area, and it is possible to reduce the cost because the area of the ion exchange membrane can be reduced.

  (5) The redox flow battery which concerns on 1 aspect of this invention is equipped with the cell stack as described in said (4).

  According to the redox flow battery, since the cell stack according to one embodiment of the present invention is provided, the size and cost can be reduced.

[Details of the embodiment of the present invention]
A specific example of a cell frame according to an embodiment of the present invention will be described below with reference to the drawings. The cell stack and the redox flow battery according to the embodiment of the present invention are characterized by using the cell frame according to the embodiment of the present invention, and other configurations are described with reference to FIGS. 6 and 7. A configuration similar to the conventional one can be adopted. Therefore, below, the detailed description is abbreviate | omitted about a cell stack and a redox flow battery. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included.

[Embodiment 1]
A cell frame 20A according to the first embodiment will be described with reference to FIG. The cell frame 20A includes a frame body 22 and a bipolar plate 21 provided inside the frame body 22. The frame body 22 is integrally formed on the outer periphery of the bipolar plate 21 by injection molding or the like. The cell frame 20 </ b> A has a recess 24 for accommodating an electrode (not shown) inside the frame body 22 by the inner peripheral surface of the frame body 22 and the surface of the bipolar plate 21. For example, the frame body 22 constituting the cell frame 20A may be formed of plastic or rubber such as vinyl chloride resin, polypropylene, polyethylene, fluorine resin, or epoxy resin. The bipolar plate 21 can be made of plastic carbon.

(Frame)
The frame 22 has a rectangular outer shape, and is composed of a pair of long pieces and a pair of short pieces. The frame 22 includes a liquid supply side piece 221 and a drainage side piece 222 provided to face the liquid supply side piece 221. The liquid supply side piece 221 has a liquid supply manifold 201 through which the electrolyte supplied to the recess 24 flows, and a liquid supply slit 211 that supplies the electrolyte from the liquid supply manifold 201 to the recess 24. The drainage side piece 222 has a drainage manifold 203 through which the electrolyte discharged from the recess 24 flows, and a drainage slit 213 that discharges the electrolyte from the recess 24 to the drainage manifold 203. Both end portions of the liquid supply side piece 221 and the liquid discharge side piece 222 are connected to each other by a pair of connection pieces 223 that face each other and are orthogonal to the liquid supply side piece 221 and the liquid discharge side piece 222. In the cell frame 20 </ b> A illustrated in FIG. 1, one long piece (the lower long piece in FIG. 1) of the frame 22 is the liquid supply side piece 221, and the other long piece (the upper long piece in FIG. 1). It is the drainage side piece 222, and the connecting piece 223 constitutes a short piece of the frame body 22. Here, when the cell frame 20A is viewed in plan, the direction in which the liquid supply side piece 221 and the drainage side piece 222 face each other is the vertical direction (vertical direction), and the direction orthogonal to the vertical direction is the horizontal direction (left and right direction). In each of the vertical direction and the horizontal direction, the direction toward the inside of the frame is defined as the inside, and the opposite direction is defined as the outside.

  The liquid supply manifold 201 and the liquid discharge manifold 203 are provided through the front and back of the frame body 22 (the liquid supply side piece 221 and the liquid discharge side piece 222). The liquid supply slit 211 and the liquid discharge slit 213 are formed on the surface of the frame 22 (the liquid supply side piece 221 and the liquid discharge side piece 222), and one end of each of the slits 211 and 213 is formed in each manifold 201 and 203, respectively. The other end is connected to a recess 24 formed inside the frame body 22. In the case of the cell frame 20A illustrated in FIG. 1, the liquid supply manifold 201 is provided at the lower left corner of the frame body 22, and the drainage manifold 203 is provided at the upper right corner that is the diagonal position. A liquid supply slit 211 extending from the liquid supply manifold 201 is connected to the lower edge of the recess 24, and a liquid discharge slit 213 extending from the liquid discharge manifold 203 is connected to the upper edge of the recess 24. That is, the electrolytic solution is supplied from the lower side of the concave portion 24 into the concave portion 24, and the electrolytic solution is discharged from the upper side of the concave portion 24. Usually, a rectification part (not shown) is formed at the inner edge of the frame 22 (the liquid supply side piece 221 and the drainage side piece 222), and the other ends of the slits 211 and 213 are connected to the rectification part. Yes. The rectifying unit has a function of diffusing the electrolyte supplied from the liquid supply slit 211 along the lower edge of the recess 24 or condensing the electrolyte discharged from the upper edge of the recess 24 to the drain slit 213. Have. By this rectifying portion, the electrolytic solution flows in the concave portion 24 from the lower edge portion of the concave portion 24 toward the upper edge portion.

  In FIG. 1, only the supply manifold 201 and the drainage manifold 203 for the positive electrode electrolyte are shown, but the frame body 22 (the supply side piece 221 and the drainage side piece 222) has a negative electrode electrolyte solution. A liquid supply manifold and a drainage manifold are formed. Specifically, a negative electrode electrolyte supply manifold and a drain manifold are similarly formed at positions symmetrical to the supply manifold 201 and drain manifold 203 for the positive electrolyte. Further, on the back surface of the frame body 22 (the liquid supply side piece 221 and the drainage side piece 222), each of the manifolds for the negative electrode electrolyte solution and the liquid supply slit 211 and the drainage slit 213 for the positive electrode electrolyte solution are provided. A liquid supply slit and a liquid discharge slit are formed to connect the recess 24.

(Concave)
The shape of the recess 24 is typically such that when a virtual rectangle circumscribing the outline of the recess 24 is drawn, the corners of the rectangle are cut off. Specifically, the virtual rectangle is two virtual straight lines parallel to the horizontal direction passing through the points (upper end and lower end) positioned on the outermost side in the vertical direction of the recess 24 and the outermost side in the horizontal direction of the recess 24. It is a rectangle formed by two virtual straight lines parallel to the vertical direction passing through points (left end, right end) located at. In the cell frame 20A illustrated in FIG. 1, the shape of the recess 24 is a hexagonal shape, and the height (length in the vertical direction) of the recess 24 is maximized on the center side (inside) in the width direction (lateral direction). It becomes smaller toward both sides (outside). In other words, the shortest vertical distance from the upper edge or the lower edge of the recess 24 to the outer periphery of the frame body 22 is minimum on the center side (inside) in the width direction (lateral direction) and maximum on both left and right sides (outside). It has become. That is, with respect to the point (upper end and lower end) positioned on the outermost side in the vertical direction of the recess 24, the left and right corners of the recess 24 (inner edges and connection pieces of the liquid supply side piece 221 and the drainage side piece 222). The position of the intersection with the inner edge of 223 is located inside in the vertical direction.

(Position relationship between manifold and recess)
In the cell frame 20 </ b> A illustrated in FIG. 1, in the liquid supply side piece 221 of the frame body 22, a point (upper end) positioned at the innermost side in the vertical direction of the liquid supply manifold 201 is positioned at the outermost side in the vertical direction of the recess 24. It is located on the inner side (upper side) than the point (lower end). Also in the drainage side piece 222, the point (lower end) located on the innermost side in the vertical direction of the drainage manifold 203 is on the inner side (lower side) than the point (upper end) located on the outermost side in the vertical direction of the recess 24. ). That is, the point located on the innermost side in the vertical direction in both manifolds 201 and 203 is located on the inner side than the point located on the outermost side in the vertical direction of the recess 24.

{Function and effect}
In the conventional cell frame 20 illustrated in FIG. 8, the shape of the concave portion 24 is rectangular, and the point located on the innermost side in the vertical direction of the manifolds 201 and 203 is located on the outermost side in the vertical direction of the concave portion 24. It is located outside the point. On the other hand, in the cell frame 20A of the first embodiment, the point located on the innermost side in the vertical direction of each manifold 201, 203 is located on the inner side than the point located on the outermost side in the vertical direction of the recess 24. According to the cell frame 20A of the first embodiment, the height Fh of the cell frame 20 (frame body 22) can be reduced as compared with the prior art while maintaining the area of the concave portion 24 equivalent to that of the prior art, and the frame body 22 can be reduced. It is possible to reduce the outer area of the. Therefore, by using the cell frame 20A as a component part of the RF battery, it is possible to reduce the size while maintaining the electrode area, and it is possible to reduce the area of the ion exchange membrane, thereby reducing the cost.

[Embodiment 2]
In the cell frame 20A of the first embodiment described above, the configuration in which the point located on the innermost side in the vertical direction of the manifolds 201 and 203 is located on the inner side than the point located on the outermost side in the vertical direction of the recess 24 has been described. In the second embodiment, in addition to this, a mode in which the point located on the innermost side in the horizontal direction of the manifolds 201 and 203 is located on the inner side than the point located on the outermost side in the horizontal direction of the recess 24 will be described. Hereinafter, with reference to FIG. 2, the cell frame 20B according to the second embodiment will be described focusing on differences from the cell frame 20A of the first embodiment.

  The cell frame 20B of the second embodiment illustrated in FIG. 2 is similar to the first embodiment in that the point located on the innermost side in the vertical direction in both manifolds 201 and 203 is located on the outermost side in the vertical direction of the recess. Is also located inside. In addition, in the cell frame 20B of the second embodiment, in the liquid supply side piece 221 of the frame body 22, the point (right end) located in the innermost side in the horizontal direction of the liquid supply manifold 201 is the horizontal direction of the recess 24. It is located on the inner side (right side) of the outermost point (left end). Also, in the drain side piece 222, the point (left end) located on the innermost side in the horizontal direction of the drainage manifold 203 is on the inner side (left side) than the point (right end) located on the outermost side in the horizontal direction of the recess 24. Is located. That is, the point located on the innermost side in the horizontal direction in both manifolds 201 and 203 is located on the inner side of the point located on the outermost side in the horizontal direction of the recess 24.

  According to the cell frame 20B of the second embodiment, the width Fw of the cell frame 20 (frame body 22) can be reduced as compared with the first embodiment while maintaining the area of the recess 24 equivalent to that of the first embodiment. It is possible to make the outer area of 22 smaller. In addition, the dotted line in a figure has shown the size of 20 A of cell frames of Embodiment 1. FIG.

  Furthermore, in the cell frame 20B, the point (left end) located on the outermost side in the lateral direction of the liquid supply manifold 201 is located on the inner side (right side) than the point (left end) located on the outermost side in the lateral direction of the recess 24. It may be. Further, the point (right end) located on the outermost side in the horizontal direction of the drainage manifold 203 may be located on the inner side (left side) than the point (right end) located on the outermost side in the horizontal direction of the recess 24. That is, the point located on the outermost side in the horizontal direction in both manifolds 201 and 203 may be located on the inner side of the point located on the outermost side in the horizontal direction of the recess 24. Thereby, the width Fw of the cell frame 20 (frame body 22) can be further reduced, and the outer area of the frame body 22 can be further reduced. The point located on the outermost side in the lateral direction in each manifold 201, 203 may be in the same lateral position as the point located on the outermost side in the lateral direction of the recess 24.

[Embodiment 3]
In the cell frame 20A of the first embodiment described above, the configuration in which the point located on the innermost side in the vertical direction of the manifolds 201 and 203 is located on the inner side than the point located on the outermost side in the vertical direction of the recess 24 has been described. In the third embodiment, a mode in which the point located on the outermost side in the vertical direction of the manifolds 201 and 203 is further described on the inner side than the point located on the outermost side in the vertical direction of the recess 24 will be described. Hereinafter, with reference to FIG. 3, the cell frame 20C according to the third embodiment will be described focusing on differences from the cell frame 20A of the first embodiment.

  In the cell frame 20 </ b> C of the third embodiment illustrated in FIG. 3, in the liquid supply side piece 221 of the frame body 22, the point (lower end) located on the outermost side in the vertical direction of the liquid supply manifold 201 is the vertical direction of the recess 24. It is located on the inner side (upper side) of the outermost point (lower end). Also, in the drain side piece 222, the point (upper end) located on the outermost side in the vertical direction of the drainage manifold 203 is inside (lower side) than the point (upper end) located on the outermost side in the vertical direction of the recess 24. ). That is, the point located on the outermost side in the vertical direction in both manifolds 201 and 203 is located on the inner side of the point located on the outermost side in the vertical direction of the recess 24. The point located on the outermost side in the vertical direction in each manifold 201, 203 may be at the same vertical position as the point located on the outermost side in the vertical direction of the recess 24.

  According to the cell frame 20C of the third embodiment, the height Fh of the cell frame 20 (frame body 22) can be further reduced as compared with the first embodiment while maintaining the area of the recess 24 equivalent to that of the first embodiment. The outer area of the frame 22 can be further reduced. In addition, the dotted line in a figure has shown the size of 20 A of cell frames of Embodiment 1. FIG.

[Modification]
In the embodiment described above, the case where the shape of the concave portion 24 is a hexagonal shape is illustrated, but the shape of the concave portion 24 is not limited to this. For example, the shape illustrated in FIG.

  The cell frame 20a shown in the first figure from the top of FIG. 4 has a shape in which the concave portion 24 has a shape in which a corner portion of a virtual rectangle circumscribing the outline of the concave portion 24 is chamfered linearly (so-called octagonal shape) It is.

  The cell frames 20b and 20c shown in the second and third diagrams from the top of FIG. 4 have a shape of the recess 24 in which the corners of the above-described virtual rectangle are chamfered in a curved shape. The cell frame 20b has a rounded chamfered shape so that the corners of the rectangle swell outward. The cell frame 20c has a rounded chamfered shape so that the corners of the rectangle are recessed inward.

  The cell frame 20d shown in the fourth figure from the top in FIG. 4 has a shape in which the concave portion 24 is cut out by two straight lines in which the corners of the virtual rectangle described above are orthogonal (so-called cross shape). is there.

  In any of the cell frames 20a to 20d illustrated in FIG. 4, the point located on the innermost side in the vertical direction of the manifolds 201 and 203 is located on the inner side than the point located on the outermost side in the vertical direction of the recess 24. . In addition, the point located on the innermost side in the lateral direction of the manifolds 201 and 203 is located on the inner side of the point located on the outermost side in the lateral direction of the recess 24.

[Contrast between implementation model and comparative model]
Using the cell frame 20X (implementation model) shown in the upper diagram of FIG. 5 and the cell frame 20Y (comparison model) shown in the lower diagram of FIG. 5, the area reduction effect by the cell frame according to the embodiment was verified.

  In the cell frame 20X of the implementation model, the shape of the concave portion 24 is hexagonal, and the point located on the innermost side in the vertical direction of each manifold 201, 203 is inside the point located on the outermost side in the vertical direction of the concave portion 24. Is located. In addition, the point located on the outermost side in the lateral direction of the manifolds 201 and 203 is located on the inner side of the point located on the outermost side in the lateral direction of the recess 24. On the other hand, in the comparative model cell frame 20Y, the shape of the concave portion 24 is rectangular as in the conventional case, and the point located on the innermost side in the vertical direction of the manifolds 201 and 203 is located on the outermost side in the vertical direction of the concave portion 24. It is located outside the point to be. In the cell frames of the implementation model and the comparative model, the dimensions were set as follows so that the areas of the recesses 24 were equal.

(Prerequisite)
As preconditions, margins in the vertical and horizontal directions of the frame 22 and the diameters Md of the manifolds 201 and 203 were set as follows.
Vertical margin mv: 5cm
Horizontal margin mc: 10 cm
Manifold diameter Md: 5cm

(Execution model: cell frame 20X)
Concave shape: hexagonal shape Concave height (maximum height) Ch: 30 cm
Recess width (maximum width) Cw: 80 cm
The shortest vertical distance ev from the upper or lower end of the recess to the outer periphery of the frame: 7 cm
Vertical distance difference dv between the upper end of the recess and the left and right corners dv: 5 cm
Recessed area: 2000 cm ²

(Comparative model: Cell frame 20Y)
Concave shape: rectangular shape Concave height Ch: 30 cm
Recess width (maximum width) Cw: 67 cm
The shortest vertical distance ev from the upper or lower end of the recess to the outer periphery of the frame body: 12 cm
Vertical distance difference between the upper end of the recess and the left and right corners: 0 cm
Area of the recess: 2010cm ² (approximately 2000 cm ²⁾

  Based on the above dimensional conditions, the cell frame size and area (outer dimensions and outer area of the frame 22) in the implementation model and the comparison model are calculated as follows.

(Execution model: cell frame 20X)
Cell frame (frame) height Fh: 44 cm
Cell frame (frame) width Fw: 100 cm
Cell frame area (outer frame area): 4400 cm ²

(Comparative model: Cell frame 20Y)
Cell frame (frame) height Fh: 54 cm
Cell frame (frame) width Fw: 87 cm
Cell frame area (frame body outer area): 4698 cm ² (about 4700 cm ² )

  From the above verification results, comparing the implementation model with the comparison model, it can be seen that the implementation model has a smaller cell frame area (outer area of the frame body 22) than the comparison model. In this case, the area reduction effect of the implementation model with respect to the comparison model is [(4700-4400) / 4700] ≈6.4 (%). Therefore, according to the cell frame according to the embodiment, it is possible to reduce the area of the cell frame (outer area of the frame body 22) as compared with the conventional one while maintaining the concave area equivalent to the conventional one. I understand.

  Specifically, in the cell frame of the embodiment, the outer shape area of the frame body is reduced while the shape of the concave portion is substantially the same as the concave portion area as compared to the rectangular cell frame. The following conditions are met.

  In the cell frame of the embodiment and the cell frame having a rectangular recess, the shorter one of the vertical distances from the manifold and the opening edge of the recess to the outer periphery of the frame is defined as the vertical margin and the horizontal The shorter one of the direction distances is defined as the horizontal margin, and the margins in the respective directions are the same. The manifolds have the same shape and the same size. Then, when designed so that the areas of the recesses in both cell frames are substantially the same, the cell frame of the embodiment has a specific positional relationship between the manifold and the recesses, and the shape of the recesses is a rectangular cell. The shape of the recess is such that the outer area of the frame is smaller than that of the frame.

  The cell frame of the present invention can be suitably used for a redox flow battery.

DESCRIPTION OF SYMBOLS 100 cell 101 ion exchange membrane 102 positive electrode cell 104 positive electrode 103 negative electrode cell 105 negative electrode 106 positive electrode electrolyte tank 108,110 conduit 112 pump 107 negative electrode electrolyte tank 109,111 conduit 113 pump 20,20A-20C, 20a- 20d, 20X, 20Y Cell frame 21 Bipolar plate 22 Frame body 200 Manifold 201, 202 Supply manifold 203, 204 Drain manifold 210 Slit 211, 212 Supply slit 213, 214 Drain slit 221 Supply side piece 222 Discharge side piece 223 Connecting piece 24 Recess 25 Seal member 10S Cell stack 250 End plate 300 Redox flow battery (RF battery)

Claims (5)

A cell comprising a frame and a bipolar plate provided inside the frame, wherein a recess for accommodating an electrode is formed inside the frame by an inner peripheral surface of the frame and a surface of the bipolar plate A frame,
The frame is
A liquid supply side piece having a liquid supply manifold through which the electrolyte supplied to the recess flows, and a liquid supply slit for supplying the electrolyte from the liquid supply manifold to the recess;
A drainage manifold provided facing the liquid supply side piece and having a drainage manifold through which the electrolyte discharged from the recess flows, and a drainage slit for discharging the electrolyte from the recess to the drainage manifold. A liquid side piece,
The direction in which the liquid supply side piece and the drainage side piece face each other is the vertical direction, the direction orthogonal to the vertical direction is the horizontal direction, and the inside of the frame body in each of the vertical direction and the horizontal direction. When the direction to go is inside and the opposite direction is outside,
A cell frame in which a point located on the innermost side in the vertical direction in at least one of the liquid supply manifold and the drainage manifold is located on an inner side than a point located on the outermost side in the vertical direction of the recess.   The cell frame according to claim 1, wherein a point located on the innermost side in the lateral direction in the at least one manifold is located on an inner side than a point located on the outermost side in the lateral direction of the recess.   3. The cell frame according to claim 1, wherein a point located on the outermost side in the vertical direction in the at least one manifold is located on an inner side than a point located on the outermost side in the vertical direction of the recess.   A cell stack formed by laminating a plurality of cell frames according to any one of claims 1 to 3, a positive electrode, an ion exchange membrane, and a negative electrode.   A redox flow battery comprising the cell stack according to claim 4.

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