JP2005228617A - Double-sided terminal board for redox flow battery cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a redox flow battery stack in which a bipolar board constituting a cell as a terminal board can be used as it is, and at the same time the number of the terminal boards can be made less. <P>SOLUTION: This is two sets of the redox flow battery cell stacks in which, on the both sides of single double-sided terminal board, an arbitrary numbers of cells 1 are laminated, and in the respective outsides of the laminated cells 1, terminal boards 3a, 3b are arranged, and this is the two sets of the redox flow battery cell stacks in which the external shape and a material of the bipolar board member constituting the cell 1 and the external shape and the material of the double-sided terminal board 2 are the same. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a terminal plate for a redox flow battery (or redox flow type secondary battery) cell stack, a redox flow battery cell stack characterized by the arrangement of two cell stacks, and a redox flow battery.

  A redox flow battery (or a redox flow type secondary battery) is a battery that uses a change in the valence of an ion (oxidation-reduction reaction) in an electrolytic solution as an active material, has little deterioration of the active material, and has a battery life. It has a feature of being long, capable of high-speed response and high output, and having no possibility of environmental pollution without generating exhaust gas. This battery is composed of cells in which electrodes (a positive electrode and a negative electrode) and a frame having a bipolar plate are disposed on both sides of a diaphragm such as an ion exchange membrane. A positive electrode solution is circulated in a positive electrode chamber located between the diaphragm and the bipolar plate and provided with a positive electrode. At the same time, the negative electrode solution is circulated in the negative electrode chamber located between the diaphragm and the bipolar plate and provided with the negative electrode. (Hereinafter, the positive electrode solution and the negative electrode solution may be collectively referred to as an electrolytic solution.)

By stacking a plurality of the above cells, a redox flow battery suitable for a desired voltage is formed. However, when the number of stacked cells is increased, the shunt current (leakage current) increases and the system loss increases. For this reason, a pair of terminal electrodes are arranged at both ends of a cell stack in which a certain number (for example, 25) of cells are stacked, and is used as a constituent unit of a redox flow battery. (For example, refer to Patent Document 1.)
Japanese Patent Laid-Open No. 2-183968 (FIG. 11)

  A conventional cell stack, which is a structural unit of a redox flow battery, requires a pair of terminal plates that house terminal electrode plates and a supply / discharge plate that is a member for attaching a positive electrode solution and a negative electrode solution. Therefore, two terminal plates and a supply / discharge plate are required for a single cell stack.

  An object of the present invention is to obtain a redox flow battery cell stack that can reduce the number of terminal plates and supply / discharge plates. Moreover, this invention makes it a subject to obtain the redox flow battery stack which can use the bipolar plate which comprises a cell as a terminal board as it is. Furthermore, the subject of this invention is obtaining the redox flow battery which uses such a cell stack.

  A double-sided terminal plate for a redox flow battery cell stack according to the present invention is provided with a bipolar plate, fixed to an outer peripheral portion of the bipolar plate, a first recess having one surface of the bipolar plate as a bottom surface, and the bipolar plate A frame that forms a second recess having the other surface of the plate as a bottom surface, a first liquid supply passage that is provided in the frame and communicates with the outside of the frame and the first recess, and a first drainage passage, and is provided in the frame The second liquid supply passage and the second drainage passage that communicate with the outside of the frame and the second recess, all of the liquid that passes through the inlet formed on the surface of the frame by the first liquid supply passage flows into the first recess. And all the liquid which passes the inlet_port | entrance which a 2nd liquid supply path forms in the said frame surface flows into a 2nd recessed part, It is characterized by the above-mentioned.

Two sets of redox flow battery cell stacks according to the present invention are formed by laminating an arbitrary number of cells on both sides of the double-sided terminal plate for redox flow battery cell stacks according to claim 1, and on each outer side of the laminated cells. A terminal board is arranged.
In the embodiment of the present invention, the two sets of redox flow battery cell stacks may have the same outer shape and material of the bipolar plate member constituting the cell and the outer shape and material of the bipolar plate member constituting the double-sided terminal plate. .
The redox flow battery according to the present invention uses two sets of redox flow battery cell stacks according to the present invention.
The embodiments of the present invention described above can be combined as much as possible.

The double-sided terminal board of the present invention can be used as it is without newly processing the bipolar plate constituting the cell. As a result, the manufacturing cost of the redox flow battery can be reduced.
The two sets of redox flow battery cell stacks of the present invention can reduce the necessary terminal plates and supply / discharge plates. As a result, the assembly man-hour at the time of manufacture can be reduced.
The redox flow battery of the present invention is a redox flow battery having the above effects.

  The double-sided terminal board for redox flow battery cell stack according to the present invention (hereinafter sometimes referred to as a double-sided terminal board), a redox flow battery cell stack (hereinafter sometimes referred to as a cell stack), and a redox flow battery according to the following examples. Will be explained. The dimensions, materials, shapes, relative positions, etc. of the members and parts described in the embodiments of the present invention are not intended to limit the scope of the present invention to those unless otherwise specified. It is merely an illustrative example.

1 is an exploded explanatory view of two sets of cell stacks, FIG. 2 is a cross-sectional explanatory view of the two sets of cell stacks, and FIG. 3 is an explanatory view of a double-sided terminal board.
In FIG. 1, the two cell stacks 6 are composed of one cell stack 5a and one cell stack 5b. The cell stack 5a is configured by superimposing the terminal plate 3a and the supply / distribution plate 4a on one of a plurality of laminated bodies of frames 7 having bipolar plates, and superposing one concave portion of the double-sided terminal plate 2 on the other. The The cell stack 5b is configured by superimposing the terminal plate 3b and the supply / distribution plate 4b on one of the laminates of the frame 7 having a plurality of bipolar plates and the other concave portion of the double-sided terminal plate 2 on the other. . The double-sided terminal board 2 is located between the two sets of cell stacks and is a constituent member common to the two sets of cell stacks 5a and 5b.

  Referring to FIG. 2, one set of cell stacks 5 a and 5 b includes a plurality of redox flow battery cells (hereinafter also referred to as cells) 1. In the cell 1, a positive electrode 14 and a negative electrode 15 (hereinafter, the positive electrode and the negative electrode may be referred to as electrodes) are arranged on both sides of a rectangular diaphragm 11 which is an ion exchange membrane, and a rectangular bipolar plate (bipolar plate) is provided on each of the two sides. 12 is arranged. The outer peripheral portion of the bipolar plate 12 is accommodated in a groove formed in the inner peripheral wall of the frame 13 and is sandwiched and integrated with the frame. In addition, in the region of the bipolar plate 12 disposed in the frame 13, a concave portion (electrode chamber) for accommodating the positive electrode 14 and the negative electrode 15 is formed.

The frame 13 is made of an acid resistant material such as polyvinyl chloride resin, and the positive electrode 14 and the negative electrode 15 are made of carbon fiber felt.
The distribution plate 4a has a positive electrode liquid inlet 72a, a negative electrode liquid inlet, a positive electrode liquid outlet, and a negative electrode liquid outlet 75a on the side surface, and a hole-like portion extending from these holes opens on the overlapping surface of the distribution plate. Yes. The distribution board 4b has the same structure as the distribution board 4a.

  The terminal plate 3a has a rectangular plate shape, and a concave portion (terminal plate chamber) for accommodating the negative electrode 45a is formed on one surface thereof. One through hole is provided at each of the four corners of the overlapping surface of the terminal board 3a, and the positive and negative electrode liquids can flow between the supply / distribution board 4a and the frame 13.

The terminal plate 3b has a rectangular plate shape, and a concave portion (terminal plate chamber) for accommodating the positive electrode 44b is formed on one surface thereof. One through hole is provided at each of the four corners of the overlapping surface of the terminal plate 3b, and the positive electrode solution and the negative electrode solution can flow between the supply / distribution plate 4b and the frame 13.
The distribution board 4 and the terminal board 3 are made of an acid resistant material such as polyvinyl chloride resin, and the positive terminal 44 and the negative terminal 45 are made of a copper plate. Moreover, you may comprise with the same carbon fiber felt as an electrode.

  The double-sided terminal board 2 is formed by surrounding a peripheral part of a rectangular bipolar plate (bipolar plate) 42 with a frame 43. The outer peripheral portion of the bipolar plate 42 is accommodated in a groove formed in the inner peripheral wall of the frame 43 and is sandwiched and integrated with the frame. The region of the bipolar plate 42 disposed on the frame 43 is formed with a first recess 48 and a second recess 49 to accommodate the positive electrode 44a and the negative electrode 45b. The first recess 48 and the second recess 49 are electrode chambers. The first recess 48 has one surface of the bipolar plate 42 as a bottom surface and is surrounded by a frame 43 at four sides. The second concave portion 49 has the other surface of the bipolar plate 42 as a bottom surface and is surrounded by the frame 43 at four sides.

Referring to FIG. 3, negative electrode 45 b is accommodated in first recess 48 of double-sided terminal plate 43. There is a groove-like gap between the upper end surface of the inner edge of the first recess 48 and the upper end surface of the negative electrode 45b, and the drainage rectification path 57 is formed by covering this groove with a protective plate 65a.
Similarly, there is a groove-like gap between the lower end face of the inner edge of the first recess 48 and the lower end face of the negative electrode 45b, and the liquid supply rectification path 56 is formed by covering this groove with the protective plate 65b. Yes. The protection plates 65a and 65b are narrow and long plates made of an acid resistant material such as polyvinyl chloride resin.

Cutout step portions are formed on the upper and lower end surfaces of the inner edge portion of the first recess 48. The notch depth of the notch step is equal to the thickness of the protective plates 65a and 65b and is shallower than the depth (thickness) of the first recess. Therefore, the frame portion in which the notch step portion is formed is a two-step concave portion. This notch step is a locking portion for positioning the protection plates 65a and 65b, and extends over the overlapping surface 67 of the frame beyond the inner edge of the recess. When the protective plates 65a and 65b are attached to the frame 43, the surface of the protective plate is flush with the frame surface.
On the back side of the first recess 48 as viewed from the paper of FIG. 3, there is a second recess 49 formed in the frame 43, which is configured in the same manner as the first recess 48.

  At the four corners of the frame 43, there are provided a liquid supply passage 51, a liquid discharge passage 52, a liquid supply passage 53, and a liquid discharge passage 54, which are holes that penetrate the overlap surface 67 and the overlap surface 68. The liquid supply rectification path 56 is electrically connected to the liquid supply path 51 via the liquid supply side conduction path 58. Further, the drainage rectification path 57 is electrically connected to the drainage passage 52 through the drainage side conduction path 59. The liquid supply side conduction path 58 and the drain side conduction path 59 are each formed by forming a groove in the overlapping surface 67 of the frame 43 and covering the opening of the groove with protective plates 65b and 65a. In addition, the hole arrange | positioned coaxially with the liquid supply channel | path 51 and the drainage channel | path 52 is opened in one edge part of the protection plates 65b and 65a.

  On the overlapping surface 68 side of the liquid supply passage 51 and the drainage passage 52, stoppers 71a and 71b are respectively attached. The total amount of the electrolyte passing through the opening surface 61 serving as the inlet of the liquid supply passage 51 passes through the liquid supply passage-side conduction path 58 and reaches the liquid supply rectification path 56 serving as the outlet to the first recess 48.

Plugs 71c and 71d are attached to the overlapping surface 67 side of the liquid supply passage 53 and the drainage passage 54, respectively. The entire amount of the electrolyte passing through the opening surface serving as the inlet of the liquid supply passage 53 passes through the liquid supply passage-side conduction path and reaches the liquid supply rectification path serving as the outlet to the second recess 49.
In order to prevent leakage of the electrolyte flowing into the first recess 48, the outer peripheral portion of the diaphragm 11 is used as a seal member. The diaphragm 11 is illustrated by a one-dot chain line. When the overlapping surface of the frame 13 of the adjacent cell is overlapped with the overlapping surface 67 and tightened, the outer peripheral portion of the diaphragm 1 is partially deformed and exhibits a sealing action. In this example, the part where the protective plate protrudes from the outer peripheral end of the diaphragm (the liquid supply side conduction path 58 and / or the drain side conduction path 59 part) is the overlapping surface of the frame, the protective plate, the outer peripheral part of the diaphragm as a seal member, The overlapping surface of the other frame is sandwiched and tightened.

FIG. 4 is an explanatory diagram of the frame 7 including the bipolar plate constituting the cell 1. A positive electrode 14 is accommodated in a recess 18 of the frame 7 having a bipolar plate. There is a groove-like gap between the upper end surface of the inner edge of the recess 18 and the upper end surface of the positive electrode 14, and the drainage rectification path 27 is formed by covering the groove with a protective plate 35a.
Similarly, there is a groove-like gap between the lower end surface of the inner edge of the recess 18 and the lower end surface of the positive electrode plate 14, and the liquid supply rectification path 26 is formed by covering the groove with the protective plate 35 b. . The protection plates 35a and 35b are narrow and long plates made of an acid resistant material such as polyvinyl chloride resin.

  Cutout steps are formed on the upper and lower end surfaces of the inner edge of the recess 18. The notch depth of the notch step is equal to the thickness of the protective plates 35a and 35b and is shallower than the depth (thickness) of the recess. Therefore, the frame portion in which the notch step portion is formed is a two-step concave portion. This notch step portion is a locking portion for positioning the protection plates 35a and 35b, and extends over the overlapping surface of the frame beyond the inner edge of the recess. When the protective plates 35a and 35b are attached to the frame 13, the surface of the protective plate and the frame surface are flush with each other.

On the back side of the recess 18 as viewed from the paper surface of FIG. 4, there is a recess formed in the frame 13 for accommodating the negative electrode plate 15 and is configured in the same manner as the recess 18.
At the four corners of the frame 13, there are provided a liquid supply passage 21, a liquid discharge passage 22, a liquid supply passage 23, and a liquid discharge passage 24, which are holes penetrating the overlap surface 37 and the overlap surface 38. The liquid supply rectification path 26 is electrically connected to the liquid supply path 21 via the liquid supply side conduction path 28. Further, the drainage rectification path 27 is electrically connected to the drainage passage 22 through the drainage side conduction path 29. The liquid supply side conductive path 28 and the drain side conductive path 29 are each formed by forming a groove in the overlapping surface 37 of the frame 13 and covering the opening of the groove with protective plates 35b and 35a. In addition, the hole arrange | positioned coaxially with the liquid supply channel | path 21 and the drainage channel | path 22 is opened in one edge part of the protection plates 35b and 35a.

  In order to prevent leakage of the electrolyte flowing into the recess 18, the outer peripheral portion of the diaphragm 11 is used as a seal member. The diaphragm 11 is illustrated by a one-dot chain line. When the overlapping surface of the frame of the adjacent cell is overlapped on the overlapping surface 37 and tightened, the outer peripheral portion of the diaphragm 1 is partially deformed and exhibits a sealing action. In the present embodiment, the portion where the protective plate protrudes from the outer peripheral end of the diaphragm (the liquid supply side conductive path 28 and / or the drain side conductive path 29 portion) is the overlapping surface of the frame, the protective plate, the outer peripheral portion of the diaphragm as a seal member, The overlapping surface of the other frame is sandwiched and tightened.

  An annular groove (not shown) is provided in the outer peripheral portion of the overlapping surface of the frame 13 and the frame 43, and an O-ring (not shown) is provided in the annular groove to prevent liquid leakage. Yes. In addition, an annular groove (not shown) is provided in the outer peripheral portion of the liquid supply / drainage passages 21-24, 51-54 (excluding the inlet where the stopper is disposed), and an O-ring ( (Not shown) is provided to prevent liquid leakage. However, even if an annular groove is provided on the outer periphery of the opening surface of the liquid supply / drainage passages 51 to 54 where the plugs are provided, the function of the cell stack is allowed.

  As described above, the frame 7 including the double-sided terminal plate 2 and the bipolar plate is exactly the same except for the presence or absence of a stopper provided in the liquid supply / drainage passage. The bipolar plate 42 constituting the double-sided terminal board 2 and the bipolar plate 12 constituting the frame 7 provided with the bipolar plate are also the same. The frame 43 and the frame 13 have the same outer shape and material. Further, the liquid supply / drainage passages 51 to 54 and the liquid supply / drainage passages 21 to 24 also penetrate the same position with the same cross-sectional area. That is, when a stopper is attached to the liquid supply / drainage passage of the frame 7 having a bipolar plate, the double-sided terminal plate 2 is completed. As the plug for arranging the liquid supply / drainage passage, any member that cuts off the conduction of the liquid, such as a rubber plate, a silicone resin plug / plate, a vinyl chloride plate, a synthetic resin plate, or the like can be used.

Furthermore, the liquid supply / drainage passages 51 to 54 of the double-sided terminal board 2 can be non-through holes instead of through holes. If a non-through hole is provided, a blocking member such as a rubber plug is unnecessary. In the present invention, the bipolar plate member that constitutes the cell and the bipolar plate member that constitutes the double-sided terminal plate have the same difference in that the liquid supply / drainage passages provided in both are through holes and non-through holes. Even if it exists, it is included in the same outer shape.
When the frame 13 is overlapped, the liquid supply passages 21 and 23 communicate with each other to form a liquid supply conduit. At the same time, the drain passages 22, 24 communicate with each other to form a drain conduit. The liquid supply conduit, the liquid supply rectification path 18 and the like constitute a liquid supply manifold for the positive electrode liquid. That is, a part of the positive electrode liquid flowing into the liquid supply conduit is diverted, passes through the liquid supply side conduction path 28, passes through the liquid supply rectification path 26, reaches the positive electrode chamber in which the positive electrode plate 14 is accommodated, and is discharged. It passes through the liquid rectification path and is guided to the drainage conduction path and drainage conduit. Similarly, a part of the remaining positive electrode solution that has reached the liquid supply conduit of the adjacent cell is diverted to reach the liquid supply rectification path. The subsequent flow of the positive electrode solution is the same as the flow of the positive electrode solution described above.

  With reference to FIG. 1, the flow of the electrolyte flowing through the cell stack 5b will be described. The flow of the positive solution entering the positive electrode inlet 72b of the distribution board is indicated by an arrow 821. The positive electrode solution flows in the direction of the arrow 822 through the liquid supply conduit. Further, a part of the positive electrode solution passes through the liquid supply manifold and flows into the positive electrode chamber. The flow of the positive electrode solution in the positive electrode chamber is indicated by an arrow 825. The flow of the positive electrode solution in the electrode chamber of the double-sided terminal board is indicated by an arrow 826. The positive solution passing through the positive electrode chamber and the terminal plate chamber flows in the direction of the arrow 823 through the drainage conduit, and is discharged from the positive electrode outlet of the supply / distribution plate 4b. A flow in the discharge direction of the positive electrode solution is indicated by an arrow 824.

An arrow 921 indicates the flow of the negative electrode liquid entering the negative electrode inlet of the supply / distribution plate 4b. The negative electrode solution flows in the direction of the arrow 922 through the liquid supply conduit. Further, a part of the negative electrode liquid passes through the liquid supply manifold and flows into the negative electrode chamber, and the flow of the negative electrode liquid in the negative electrode chamber is indicated by an arrow 925. The negative electrode solution also flows into the electrode chamber of the terminal plate 3b. The negative electrode solution that has passed through the negative electrode chamber and the terminal plate chamber flows in the direction of the arrow 923 through the drainage conduit, and is discharged from the negative electrode outlet of the distribution plate 4b. The flow in the discharge direction of the negative electrode solution is indicated by an arrow 924.
Similarly, the flow of the electrolyte in the cell stack 5a is indicated by arrows.
Furthermore, in FIG. 2, the flow direction of the positive electrode solution passing through the positive electrode solution manifold is indicated by an arrow.

  Two sets of redox flow battery cell stacks having the above-described structure were further stacked and positioned between a pair of terminal plates, and tightened with fasteners such as bolts and nuts, and were provided with an electrolyte supply pipe and a drain pipe. The main part of the redox flow battery is configured by mounting the distribution member.

FIG. 5 is an external view of the main part of the redox flow battery.
In FIG. 5, 101 is a main part of the redox flow battery. A redox flow battery is configured by adding a positive electrode solution tank, the same circulation pump, the same piping, a negative electrode solution tank, the same circulation pump, the same piping and the like to the main part.
The redox flow battery cell may have at least a pair of electrode chambers (a positive electrode chamber and a negative electrode chamber).

  As the electrolytic solution used in the redox flow battery according to the present invention, various electrolytic solutions capable of ion redox reaction can be used. For example, an electrolytic solution containing vanadium ions (vanadium sulfate aqueous solution) or an electrolytic solution constituting an iron-chromium battery (combination of an electrolytic solution containing iron ions and ions containing chromium ions) can be used.

  The redox flow battery according to the present invention is useful as a power storage secondary battery, and can be used in various fields such as load leveling, auxiliary power against instantaneous voltage drop or power failure, wind power generation or solar power leveling, It can also be used to control power demand and ensure power quality.

It is decomposition | disassembly explanatory drawing of two sets of redox flow battery cell stacks. It is sectional explanatory drawing of two sets of redox flow battery cell stacks. It is explanatory drawing of a double-sided terminal board. It is explanatory drawing of the bipolar plate. It is an external view of the principal part of a redox flow battery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Redox flow battery cell 2 Double-sided terminal board 3a, 3b Terminal board 4a, 4b Distribution board 5a, 5b 1 set of redox flow battery cell stack 6 2 sets of redox flow battery cell stack 7 Frame with bipolar plate 11 Diaphragm 42 Bipolar plate 43 Frame 48 First recess as electrode chamber 49 Second recess as electrode chamber 51, 53 Liquid supply passage 71a, 71b, 71c, 71d Plug

Claims (4)

Bipolar plates,
A frame that is fixed to the outer periphery of the bipolar plate and has a first recess having a bottom surface on one surface of the bipolar plate; and a second recess having a bottom surface on the other surface of the bipolar plate;
A first liquid supply passage provided in the frame and communicating between the outside of the frame and the first recess, a first drainage passage;
A second liquid supply passage, a second drainage passage, which is provided in the frame and communicates with the outside of the frame and the second recess;
All of the liquid passing through the inlet formed in the frame surface by the first liquid supply passage flows into the first recess,
A double-sided terminal plate for a redox flow battery cell stack, in which all the liquid passing through the inlet formed in the frame surface by the second liquid supply passage flows into the second recess.   2. Two sets of redox flow battery cell stacks, in which an arbitrary number of cells are laminated on both sides of the double-sided terminal plate for redox flow battery cell stack according to claim 1, and a terminal plate is arranged on each outer side of the laminated cells.   The two sets of redox flow battery cell stacks according to claim 2, wherein the outer shape and material of the bipolar plate member constituting the cell are the same as the outer shape and material of the bipolar plate member constituting the double-sided terminal plate. A redox flow battery using two sets of redox flow battery cell stacks according to claim 2.

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