JP2006324117A - Electrolytic liquid circulation battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damage of a member such as a cell frame and leakage of liquid by making uniform surface pressure applied on the lamination face of cells by a tightening force in lamination direction of the cell laminate by a tightening mechanism, even if there arises unevenness to the thickness of the cell laminate. <P>SOLUTION: The electrolytic liquid circulation battery comprises a cell laminate in which a plurality of plate-shape cells having a positive electrode, a diaphragm, and a negative electrode are laminated and a tightening mechanism to tighten the cell laminate in lamination direction. The tightening mechanism 3 has end plates 31 which are arranged at the outside of both ends in lamination direction of the cell laminate 200, an adjusting part 32 to adjust the spacing between the end plates, and a deformation part 33 which is installed between the outermost face in lamination direction of the cell laminate 200 and the end plate 31. The deformation part 33 covers the whole of the outermost face of the cell laminate 200 and is deformed along the outermost face of the cell laminate 200, and applies a pressure uniformly on the cell laminate when the cell laminate is pressed by the end plate 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrolyte circulation type battery having a cell laminate formed by laminating a plurality of plate-like cells each having a positive electrode, a diaphragm, and a negative electrode.

  As an electrolyte circulation type battery, for example, a redox flow battery is known. As shown in the operation principle diagram of FIG. 4, the redox flow battery includes a cell 100 separated into a positive electrode cell 100A and a negative electrode cell 100B by a diaphragm 101 made of an ion exchange membrane. The positive electrode cell 100A and the negative electrode cell 100B each incorporate a positive electrode 102 and a negative electrode 103.

  A positive electrode tank 104A that stores a positive electrode electrolyte is connected to the positive electrode cell 100A via a conduit 106A, and a negative electrode tank 104B that stores a negative electrode electrolyte is connected to the negative electrode cell 100B via a conduit 106B. Circulation pumps 105A and 105B are provided in the middle of the conduits 106A and 106B, and the electrolytes are circulated between the tanks and the cells via the conduits 106A and 106B.

  Each electrode electrolyte uses an aqueous solution of ions such as vanadium ions that change in valence. Discharge. The redox flow battery is connected to an AC / DC converter and connected to a charging target such as a power plant or a discharging target such as a consumer via the AC / DC converter. Charge and discharge.

  Moreover, as shown in Patent Document 1, a cell stack in which a plurality of cells are stacked is usually used for the redox flow battery. As shown in FIG. 5, the cell laminate 200 includes a cell frame 210 having a bipolar plate 211, a positive electrode 102 made of carbon felt, a diaphragm 101, and a negative electrode 103 made of carbon felt, which are sequentially laminated. A plurality of cells in which the positive electrode 102, the diaphragm 101, and the negative electrode 103 are arranged are formed.

  In FIG. 5, a supply / discharge plate 220 is also interposed when a plurality of cells are stacked. A plurality of cells are arranged between the two supply / discharge plates 220 to form the sub stack 201. The cell stack 200 of FIG. 5 is configured by further stacking a plurality of these substacks 201.

  The cell frame 210 includes a frame part 212 formed of an insulating synthetic resin and a bipolar plate 211 fixed to the frame part 212. The positive electrode 102 and the negative electrode 103 are formed smaller than the area of the inner peripheral portion of the frame portion 212, and the diaphragm 101 is formed larger than the area of the inner peripheral portion of the frame portion 212. When stacking the cell frames 210, the outer peripheral edge of the diaphragm 101 is sandwiched by the frame part 212, and the positive electrode 102 or the negative electrode 103 is disposed between the bipolar plate 211 and the diaphragm 101. It has become. Further, the supply / discharge plate 220 has an electrolyte flow passage and is formed of an insulating synthetic resin.

  In the cell stack 200, when the cell frames 210 are stacked, a ring-shaped seal member is interposed between the frame portions 212. Further, the end plates 31 are arranged at both ends in the stacking direction of the cell laminate 200, the connecting rods 321 are passed through the two end plates 31, and the connecting rods 321 are tightened with nuts. In a state where the laminate 200 is sandwiched, the cell laminate 200 is clamped in the stacking direction to maintain the stacked state.

Japanese Patent Laid-Open No. 2002-367659

  As the cell frame 210 that is generally used, one having a large area such as, for example, an outer peripheral shape having a width of 1000 mm and a height of 780 mm is used. In addition, since the frame portion 212 is formed with a manifold through which the electrolytic solution flows, an electrolytic solution flow groove, a seal groove into which the seal member is fitted, the cell frame 210 has a complicated shape.

  Since the cell stack 200 is usually configured by stacking about 10 to 100 cell frames 210, the frame portion 212 having a large area and a complicated stacking surface has a stacking direction. When tightened, the surface pressure may vary. As described above, when a variation in surface pressure occurs in the frame portion 212, there is a possibility that the electrolytic solution leaks or the frame portion 212 is cracked due to stress concentration.

  In particular, the frame portion 212 of the cell frame 210 may vary in the thickness of the frame portion 212 due to differences in mold finishing accuracy, synthetic resin cooling rate, and the like. As described above, when the frame portion 212 having a uniform thickness is not formed, the above-described variation in surface pressure is caused.

  Further, the thicknesses of the positive electrode 102, the diaphragm 101, and the negative electrode 103 interposed between the cell frames 210 are not uniform.

  Since the cell frame, electrode, and diaphragm are thicker or thinner at the same location, the difference in thickness in the stacking direction due to non-uniform thickness increases as the entire cell stack is stacked. To go. If the thickness becomes uneven as described above, the sealing by the sealing member provided between the frame portions cannot be performed sufficiently and liquid leakage occurs.

  By the way, in the above-described redox flow battery, the cell frame which is a constituent member of the cell laminate is formed by integrating the frame portion and the bipolar plate. There are the following two methods for integrating the frame portion and the bipolar plate. In one method, the frame part is composed of two frame pieces obtained by injection molding or the like, the outer peripheral part of the bipolar plate is sandwiched between the inner peripheral parts of both frame pieces, and these frame pieces are bonded. The frame part and the bipolar plate are integrated by bonding using an agent. In another method, the frame portion and the bipolar plate are integrated by forming the frame portion by injection molding using the bipolar plate as a core.

  In the case where the frame portion is configured by bonding thin frame pieces with an adhesive, the frame portion swells at a portion where the adhesive is applied. As a result, the swollen portion of the frame portion shrinks over time, and there is a problem that the thickness of the frame portion differs immediately after bonding and after several days have passed after bonding.

  Further, since the frame portion is formed of a synthetic resin, the thickness decreases with time due to a clamping stress due to a creep phenomenon.

  In this way, when the thickness of the frame part decreases with the passage of time, even if the cell stack is tightened using the end plate, connecting rod, and nut, the tightening state (tightening force) with the nut Since there is no change, liquid leakage may occur due to generation of a gap due to thickness reduction.

  Therefore, the main object of the present invention is to provide a surface pressure applied to the cell stack surface by the tightening force in the stacking direction of the cell stack by the tightening mechanism even if the thickness of the members constituting the cell stack is uneven. It is an object of the present invention to provide an electrolyte circulation type battery that can prevent the breakage of members such as a cell frame and the leakage of liquids.

  The electrolyte circulation type battery of the present invention has a cell laminate formed by laminating a plurality of plate-like cells having a positive electrode, a diaphragm, and a negative electrode, and a tightening mechanism for fastening the cell laminate in the laminating direction. .

  The cell laminate further includes a supply / discharge plate for supplying / discharging the electrolyte to / from the positive electrode or the negative electrode of each cell when sequentially laminating a bipolar plate, a positive electrode, a diaphragm, and a negative electrode. A terminal electrode for inputting and outputting electricity is also provided. The supply / discharge plate has an electrolyte flow passage for allowing the electrolyte to flow between the cell stack and the outside of the cell.

  The electrolyte circulation type battery of the present invention is configured, for example, by being connected via a pipe to a positive electrode tank and a negative electrode tank that store an electrolyte solution of each electrode. The electrolyte circulation type battery is connected to a load or a power system to perform charging / discharging. Further, the electrolyte circulation type battery has a configuration in which the positive electrode electrolyte is circulated between the positive electrode of the cell stack and the positive electrode tank, and the negative electrode electrolyte is circulated between the negative electrode of the cell stack and the negative electrode tank. It has become.

  The tightening mechanism described above includes an end plate disposed outside both ends of the cell stack in the stacking direction, an adjustment unit that adjusts an interval between the end plates, and a position between the outermost surface in the stacking direction of the cell stack and the end plate. And a deformation portion provided in the.

  The end plate has an area larger than the area of the cell laminate, specifically, the cell frame to which the bipolar plate is fixed.

  For example, the adjusting portion is formed by a connecting rod that passes through two end plates, a nut that is attached to an end of the connecting rod, a coil spring that is interposed between the nut and the end plate, and is inserted through the connecting rod. Can be configured.

  A number of insertion holes through which the connecting rods are inserted are formed on the entire circumference of the outer peripheral edge portion of the end plate at appropriate intervals. By inserting the connecting rod into the insertion hole of the end plate, the connecting rod is arranged outside the cell stack.

  A screw groove having a predetermined length is formed at both ends of the connecting rod. Then, after inserting a coil spring through the connecting rod inserted through the end plate, nuts are attached to both ends of the connecting rod. By tightening the nut, the interval between the end plates becomes narrower, the cell stack is pressed in the stacking direction by the end plate, and the cell stack is tightened.

  As described above, the deforming portion is provided between the outermost surface in the stacking direction of the cell stack and the end plate, covers the entire outermost surface of the cell stack, and deforms along the outermost surface of the cell stack. And when pressing a cell laminated body with an end plate, it becomes the structure which applies a pressure uniformly with respect to a cell laminated body.

  For example, a plate-like soft rubber member having a predetermined thickness or a bag-like member formed of a synthetic resin such as rubber and filled with fluid inside is orthogonal to the outermost surface of the cell stack. The deforming portion can be configured by holding the guide member so that it can be deformed in the stacking direction without moving or deforming in the direction.

  When the deforming portion has a bag-shaped member and a guide member, by filling the bag-shaped member with fluid, the fluid moves inside the bag due to deformation of the bag-shaped member, and the outer surface of the bag-shaped member is It follows the shape of the laminated surface of the cell laminate. The fluid filled in the bag-like member may be a gas such as air or a liquid such as water.

  In addition, the guide member prevents the bag-like member from being deformed in a direction orthogonal to the stacking direction, and the bag-shaped member is in contact with the cell stack so that the bag-shaped member is deformed in the stacking direction. The cover member is formed in a lid shape that is fitted to the outer periphery of the cell stack so as to be movable in the stacking direction.

  In the present invention, as described above, the deforming portion is provided between the cell stack and the end plate so as to cover the entire outermost surface of the cell stack. As a result, the thickness of the cell stack as a whole is uneven, and when the outermost surface of the cell stack is deformed by a thick portion or a thin portion, the deformed portion follows the outermost surface of the cell stack. When the cell stack is pressed by the end plate, it is possible to uniformly apply pressure to the cell stack.

  In particular, if the deformed portion has a bag-shaped member filled with fluid, it becomes easier to follow the deformation of the laminated surface of the cell laminate, so that when the cell laminate is pressed with an end plate, the cell laminate A uniform pressure can be applied to the entire laminated surface.

  In the case where the deformable portion has a bag-shaped member and a guide member, the bag-shaped member is further formed of a stretchable material such as rubber and is piped in the bag-shaped member outside the cell stack. The fluid storage part communicated through the pressure sensor, the pressure detection means for detecting the pressure in the bag-like member, and the supply / discharge means for supplying and discharging the fluid in the fluid storage part to and from the bag-like member can be provided. .

  By forming the bag-like member with a material that can be freely deformed by the internal pressure, the amount of fluid filled in the bag-like member can be adjusted so as to obtain a desired pressure. Then, supply / discharge of fluid to / from the bag-like member is performed by using a supply / discharge means including a pump, a four-way switching valve, etc. The amount of fluid in the bag-like member is adjusted by returning it to the fluid reservoir.

  Adjustment of the amount of fluid in the bag-like member is performed by detecting the pressure of the fluid between the bag-like member and the pump in the pipe, for example, because the bag-like member and the fluid storage portion are communicated with each other through the pipe. Based on the pressure detection result, the fluid filling amount of the fluid in the bag-like member is controlled by the supply / discharge means so that the pressure in the bag-like member does not drop below a predetermined pressure. The above-mentioned predetermined pressure is a pressure at which the cell stack is tightened without causing liquid leakage and does not cause damage due to excessive tightening of the frame or the like.

  In this way, by providing the fluid storage section and the supply / discharge means and freely adjusting the pressure of the bag-like member, it is possible to uniformly apply the tightening force by the tightening mechanism of the cell stack to the stacked surface. In other words, it is not necessary to provide a coil spring that has been disposed between the end plate and the nut.

  Moreover, when using a soft rubber member as a member which comprises a deformation | transformation part, the material can be made into soft silicone rubber or propylene rubber.

  Furthermore, the electrolyte circulation type battery of the present invention is preferably used for a redox flow battery because of the properties of the electrolyte. Note that the electrolyte circulation type battery of the present invention includes not only a type that constantly circulates the electrolyte solution but also a type that intermittently circulates the electrolyte solution.

  According to the electrolyte circulation type battery of the present invention, since the tightening mechanism is provided with the deformed portion provided between the cell stack and the end plate, the deformed portion is formed on the stack surface of the cell stack. When following the deformation and pressing the cell stack with the end plate, it is possible to uniformly apply pressure to the entire stack surface of the cell stack.

  Hereinafter, embodiments of the electrolyte circulation type battery of the present invention will be described. The electrolyte circulation type battery of this embodiment is a redox flow battery.

[First Embodiment]
(overall structure)
FIG. 1 shows a cross-sectional view seen from the front of a cell stack 200 constituting the electrolyte circulation type battery of the present invention and a perspective view of members constituting the cell. The cell stack 200 includes a plurality of cell frames 210 having bipolar plates 211, a positive electrode 102, a diaphragm 101, and a negative electrode 103. The cell laminate 200 is configured by laminating these members so that the positive electrode 102, the diaphragm 101, and the negative electrode 103 are provided between the cell frames 210.

  The cell stack 200 is configured by stacking a plurality of sub-stacks 201 that are formed by stacking a plurality of cells and disposing supply / discharge plates 220 at both ends in the stacking direction.

  Then, the cell stack 200 in a state in which a plurality of sub-stacks 201 are stacked is clamped in the stacking direction by the tightening mechanism 3 having the end plate 31, so that no liquid leakage occurs. The laminated state is maintained.

  A unit cell of the cell stack is configured by disposing a positive electrode 102, a diaphragm 101, and a negative electrode 103 between two cell frames 210. Then, the outer peripheral edge portion of the diaphragm 101 is sandwiched between the frame portions 212 of the two cell frames 210, and the positive electrode 102 or the negative electrode 103 is disposed between the diaphragm 101 and the bipolar plate 211 of the cell frame 210. I am letting.

  Although the cell stack used in the present embodiment is not shown in the drawing, the positive electrode of the cell and the positive electrode tank are connected, and the negative electrode electrolysis of the cell and the negative electrode tank are connected to constitute a redox flow battery. The operating principle of the redox flow battery of the present embodiment is the same as that described based on the operating principle diagram shown in FIG. 4, and the positive electrode electrolyte is circulated between the positive electrode tank and the positive electrode, The positive electrode electrolyte is circulated and supplied to the electrode, the negative electrode electrolyte is circulated between the negative electrode tank and the negative electrode, and the negative electrode electrolyte is circulated and supplied to the negative electrode.

(Cell frame)
As shown in FIG. 1, the cell frame 210 includes a frame part 212 and a bipolar plate 211 fixed inside the frame part 212. The frame portion 212 is a frame-like body formed of a synthetic resin mainly composed of vinyl chloride. On the other hand, the bipolar plate 211 is a rectangular plate made of conductive plastic carbon containing graphite.

  The frame part 212 and the bipolar plate 211 are integrated. In this embodiment, two frame pieces obtained by injection molding or the like are prepared, and the frame part 212 is configured by joining these frame pieces. When the two frame pieces are joined, the outer peripheral portion of the bipolar plate 211 is sandwiched and bonded between the inner peripheral portions of the two frame pieces to constitute the cell frame 210.

  As shown in FIG. 1, a plurality of manifolds 213 are formed on the long side of the frame portion 212 in the frame portion 212 of the cell frame 210. These manifolds 213 are distinguished into those used for the positive electrode electrolyte and those used for the negative electrode electrolyte. When a plurality of cell frames are stacked, the manifold 213 of each cell frame is in a continuous state, and an electrolyte flow path extending in the stacking direction is formed by these manifolds 213. Furthermore, a flow groove 214 is formed on the surface of the frame portion to communicate one manifold and the inner peripheral surface of the frame portion.

  In the electrolyte circulation type battery of this embodiment, the positive electrode electrolyte is supplied to the inner peripheral surface of the frame portion 212 from the positive electrode electrolyte manifold provided at the lower portion of the cell frame 210 via the positive electrode flow groove. The positive electrode electrolyte supplied to the surface is discharged from the positive electrode electrolyte manifold through a positive electrode flow groove provided in the upper portion. Further, the negative electrode electrolyte is also supplied to the inner peripheral surface of the frame portion 212 from the negative electrode electrolyte manifold provided at the lower portion of the cell frame 210 via the negative electrode flow groove. The negative electrode electrolyte is discharged from the negative electrode electrolyte manifold through a negative electrode flow groove provided in the upper part of the cell frame 210.

  In the cell frame 210, with the positive electrode 102, the diaphragm 101, and the negative electrode 103 disposed between the cell frames 210, the frame portions 212 of the cell frame 210 are overlapped with each other via a seal member such as packing. . At this time, the outer peripheral edge of the diaphragm 101 is sandwiched between the two frame portions 212, and the positive electrode 102 or the negative electrode 103 is interposed between the bipolar plate 211 and the diaphragm 101 within the frame 212. Arrange.

(Positive electrode and negative electrode)
As described above, since the positive electrode 102 and the negative electrode 103 are arranged between the cell frames 210, the positive electrode 102 is arranged on one surface of the bipolar plate 211, and the negative electrode 103 is arranged on the other surface. Will be. Usually, carbon felt is used for the positive electrode 102 and the negative electrode 103. The size of the electrodes 102 and 103 is set to a size corresponding to the rectangular space formed in the frame portion 212 of the cell frame 210. The electrodes 102 and 103 may be adhered to the bipolar plate 211 with an adhesive, or the electrodes 102 and 103 may be brought into contact with the bipolar plate 211 by a tightening force of a tightening mechanism 3 described later.

(diaphragm)
The diaphragm 101 uses an ion exchange membrane. As the material, an ion exchange resin containing vinyl chloride, fluororesin, polyethylene, polypropylene or the like can be used. The diaphragm 101 has substantially the same area as the cell frame 210, an area having an outer peripheral edge smaller than the outer peripheral edge of the frame part 212 and larger than the inner peripheral edge of the frame part 212, or an area larger than the outer peripheral edge of the frame part 212. It can have. When the diaphragm 101 has a portion that overlaps with the manifold formed in the frame portion 212, a through hole is formed at a location facing the manifold. The diaphragm 101 is configured to maintain the shape of the diaphragm 101 by sandwiching the outer peripheral edge portion thereof with the frame portion 212.

(Supply / discharge plate)
The supply / discharge plates 220 are disposed at both ends of the sub stack 201 in the stacking direction. Although not shown, the supply / discharge plate 220 has an electrolyte flow passage that connects each electrolyte tank and the manifold 213 of the cell frame 210. A pipe is attached to the electrolyte flow passage formed in the supply / discharge plate 220, and this pipe is connected to the electrolyte tank.

(Tightening mechanism)
As shown in FIGS. 1 and 2, the tightening mechanism 3 includes an end plate 31 disposed on the outer side in the stacking direction of the plurality of stacked sub-stacks 201, an adjustment unit 32 that adjusts the interval between the end plates 31, A deformable portion 33 provided between the outermost surface in the stacking direction of the cell stack 200 and the end plate 31 is provided.

  The end plate 31 has a larger area than the supply / discharge plate 220 and the cell frame 210, and is a portion of the end plate 31 that protrudes from the supply / discharge plate 220 and the cell frame 210. A plurality of insertion holes 311 through which the connecting rod 321 is inserted are formed.

  The adjustment unit 32 includes a plurality of connecting rods 321 for connecting the end plate 31, nuts 322 attached to both ends of the connecting rod 321, and inserted between the connecting rods 321 and arranged between the end plate 31 and the nut 322. And a coil spring 323 inserted through the connecting rod 321. The connecting rod 321 is male threaded to screw nuts 322 into both ends.

  Then, after the connecting rod 321 is inserted through the insertion hole 311 of the end plate 31, the coil spring 323 is inserted through the connecting rod 321, and nuts 322 are attached to both ends of the connecting rod 321. By tightening the nuts 322, the interval between the end plates 31 is narrowed, and the cell stack 200 is pressed in the stacking direction by the end plates 31, so that the cell stack is tightened. The coil spring 323 attached to the connecting rod 321 is used to absorb thermal expansion and contraction of members constituting the cell stack 200.

  The deformable portion 33 is provided on the outermost surface in the stacking direction of the cell stack 200, that is, between the outermost substack 201 and the end plate 31. The deformable portion 33 includes a bag-like member 331 that is filled with gas or liquid, and a guide member 332 that holds the bag-like member 331.

  The bag-shaped member 331 is formed of a synthetic resin such as rubber, and is formed in a plate shape having a size that covers the entire outermost surface of the cell laminate 200. By filling the bag-like member 331 with fluid, the fluid moves inside the bag due to deformation of the bag-like member 331, and the outer surface of the bag-like member 331 follows the shape of the outermost layer of the cell stack. ing. The fluid filled in the bag-shaped member 331 may be a gas such as air or a liquid such as water. Even if the bag-shaped member is damaged and the fluid inside flows out, the human body may be harmed. Those which do not reach are preferred.

  The guide member 332 holds the bag-shaped member 331 so that it can be deformed in the stacking direction without moving or deforming in the direction perpendicular to the stacking direction with respect to the outermost surface of the cell stack 200.

  The guide member 332 is formed in a lid shape that covers the bag-like member 331 in a state in which the bag-like member 331 is in contact with the cell laminate 200 and is fitted to the outer periphery of the cell laminate 200 so as to be movable in the stacking direction. Has been. By providing the guide member 332 so as to cover the bag-shaped member 331, it is possible to prevent the bag-shaped member 331 from being deformed in the direction orthogonal to the stacking direction, and to be deformed in the stacking direction. Thus, the pressing force on the cell stack 200 can be concentrated in the stacking direction.

  As described above, in the first embodiment, the bag-shaped member 331 and the guide member 332 are disposed between the cell stack 200 and the end plate 31, and the nut 322 is tightened to thereby form the bag-shaped member 331. Is pushed along the outermost surface of the cell stack 200 while being pressed by the end plate 31, and a clamping force is uniformly applied to the cell stack.

  In the present embodiment, since the tightening mechanism 3 is provided with the deforming portion 33, the thickness of the entire cell stack is non-uniform, and the outermost surface of the cell stack is formed by a thick portion or a thin portion. Even when the cell stack is pressed by the end plate 31, the bag-like member 331 is deformed along the outermost surface of the cell stack 200 and applies pressure to the cell stack 200 evenly. be able to.

  In particular, in the present embodiment, since the deformable portion 33 includes the bag-shaped member 331 filled with fluid, the bag-shaped member 331 can easily follow the deformation of the stacked surface of the cell stack 200, and the cell When the laminated body 200 is pressed by the end plate 31, pressure can be uniformly applied to the entire laminated surface of the cell laminated body 200.

[Second Embodiment]
In the electrolyte circulation type battery of the first embodiment, the deforming portion 33 of the tightening mechanism 3 is constituted by the bag-like member 331 and the guide member 332. In the second embodiment shown in FIG. The internal pressure of the member 331 can be adjusted. Note that the electrolyte circulation type battery of the second embodiment is different from the first embodiment only in the configuration of the tightening mechanism 3, and the other configurations are the same as those in the first embodiment, and thus the description thereof is omitted. To do.

  In the second embodiment, the tightening mechanism 3 includes an end plate 31, an adjustment unit 32, and a deformation unit 33. The members constituting the end plate 31 and the adjustment unit 32 are the same except that the coil spring is omitted.

  The deformation part 33 includes a bag-like member 331 and a guide member 332 as in the first embodiment. However, the bag-shaped member 331 is formed of a stretchable material such as rubber. Further, when the deforming portion 33 communicates with the outside of the cell stack 200 through the pipe 41 in the bag-like member 331, the pressure detecting means 5 that detects the pressure in the fluid storing portion 42, and the fluid storing portion 42 Supply / discharge means 6 for supplying and discharging the fluid inside the bag-like member 331 is also provided.

  In the second embodiment, the pressure detection unit 43, the four-way switching valve 61, and the pump 62 are provided from the bag-like member 331 side in the middle of the piping that connects the fluid storage portion 42 and the bag-like member 331. The pressure detection unit 43 is provided with a pressure sensor (pressure detection means) 5. By detecting the pressure of the fluid in the pressure detection unit 43, a bag-like member 331 having substantially the same pressure as the pressure detection unit 43 is provided. The pressure inside is detected.

  In the switching operation, the four-way switching valve 61 is connected to the pipe 41 so that the suction side of the pump 62 communicates with the fluid reservoir 42 and the discharge side is the bag-like member 331 side, or the suction side of the pump 62 is the bag. The pipe 41 is connected to communicate with the shaped member 331 so that the discharge side is the fluid reservoir 42 side. In the present embodiment, the pump 62 and the four-way switching valve 61 constitute the supply / discharge means 6.

  The pressure detection result detected by the pressure sensor 5 is sent to a control device 7 such as a computer, and the control device 7 drives and controls the four-way switching valve 61 and the pump 62 based on the pressure detection result. Yes.

  Specifically, when the pressure in the bag-shaped member 331 is within a predetermined pressure range set in advance, the four-way switching valve 61 is disabled and the pump 62 is stopped. The predetermined pressure is set to a pressure at which the tightening force of the cell stack is a tightening force that does not cause liquid leakage and does not cause damage due to excessive tightening of the frame or the like.

  When the pressure in the bag-shaped member 331 is smaller than a predetermined pressure set in advance, the four-way switching valve 61 is connected to the fluid storage section 42 on the suction side of the pump 62 and the bag-shaped member 331 is connected to the discharge side. Control is made so that the pipe 41 is connected to the side, and the pump 62 is driven until the pressure in the bag-like member 331 rises to a predetermined pressure. In this case, the fluid in the fluid reservoir 42 is supplied to the bag-shaped member 331, and the pressure in the bag-shaped member 331 can be increased.

  Further, when the pressure in the bag-like member 331 becomes higher than a predetermined pressure set in advance, the four-way switching valve 61 is connected to the bag-like member 331 on the suction side of the pump 62 and the fluid is stored on the discharge side. The pipe 41 is controlled so as to be on the side of the part 42, and the pump 62 is driven until the pressure in the bag-like member 331 drops to a predetermined pressure. In this case, the fluid in the bag-like member 331 is returned to the fluid reservoir 42, and the pressure in the bag-like member 331 can be reduced.

  As described above, in the second embodiment, the bag-shaped member 331 is formed of a material that can be freely deformed by the internal pressure, so that the amount of fluid filled in the bag-shaped member can be obtained at a desired pressure. It becomes possible to adjust. Then, the supply and discharge means 6 supplies and discharges the fluid to and from the bag-like member 331, supplies the fluid in the fluid storage part 42 into the bag-like member 331, and supplies the fluid in the bag-like member 331 to the fluid storage part 42. The pressure in the bag-shaped member 331 can be adjusted by adjusting the amount of the fluid in the bag-shaped portion 331 by returning to the back.

  Thus, by providing the fluid reservoir 42 and the supply / discharge means 6 and freely adjusting the pressure of the bag-like member 331, the fastening force by the fastening mechanism 3 is uniformly applied to the laminated surface of the cell laminate 200. Needless to say, it is no longer necessary to provide a coil spring disposed between the end plate and the nut.

  About the redox flow battery using the cell laminate of the configuration of the first embodiment described above, the bag-like member is filled with water, and the bag-like member is disposed between the cell laminate and the end plate. The pressure of the bag-like member was adjusted so that the internal pressure became 0.25 MPa when the nut was tightened. When the variation in the surface pressure of the outermost surface of the cell laminate was examined, the variation was 0.2 to 0.3 MPa. Note that, as in the prior art, the variation in the surface pressure of the outermost surface of the cell laminate in the case where no bag-like member is provided was 0.1 to 0.5 MPa.

  Next, in the battery system using the redox flow battery of this configuration, the battery test was performed 100 times under the condition of −5 ° C. to 45 ° C. As a result, in the redox flow battery of the present invention, liquid leakage and Cracks due to stress concentration in the cell frame did not occur.

  The electrolyte circulation type battery of the present invention is particularly preferably used for operation of a redox flow battery.

It is a schematic block diagram of the cell laminated body of the redox flow battery which concerns on 1st Embodiment of this invention. It is an expanded partial sectional view of the part of a modification part in a cell layered product of a 1st embodiment. It is a schematic block diagram of the cell laminated body of the redox flow battery which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the principle of operation of a redox flow battery. It is a perspective view of the cell laminated body of the conventional redox flow battery.

Explanation of symbols

100 cells 100A positive electrode cell 100B negative electrode cell
101 Diaphragm 102 Positive electrode 103 Negative electrode
104A Positive tank 104B Negative tank
105A, 105B Pump 106A, 106B Conduit
200 cell laminate
201 substack
210 Cell frame 211 Bipolar plate 212 Frame part
213 Manifold 214 Distribution groove
220 Supply / discharge plate
3 Tightening mechanism
31 End plate 311 Insertion hole
32 Adjustment section 321 Connecting rod 322 Nut 323 Coil spring
33 Deformation part 331 Bag-shaped member 332 Guide member
41 Piping 42 Fluid reservoir 43 Pressure detector
6 Supply / discharge means 62 Pump 61 Four-way selector valve
5 Pressure sensor (pressure detection means)
7 Control unit

Claims (5)

An electrolyte circulation type battery having a cell laminate constituted by laminating a plurality of plate-like cells having a positive electrode, a diaphragm, and a negative electrode, and a tightening mechanism for fastening the cell laminate in the laminating direction,
The tightening mechanism includes end plates disposed outside both ends in the stacking direction of the cell stack,
An adjustment unit for adjusting the distance between the end plates;
It is provided between the outermost surface in the stacking direction of the cell stack and the end plate, covers the entire outermost surface of the cell stack, and presses the cell stack with the end plate to the outermost surface of the cell stack. An electrolyte circulation type battery comprising: a deformation portion that deforms along the cell stack and applies pressure uniformly to the cell stack. The deformation part is
A bag-like member filled with fluid;
Covering the bag-like member with the bag-like member in contact with the cell laminate so as to prevent the bag-like member from deforming in the direction perpendicular to the stacking direction and allowing deformation in the stacking direction. The electrolyte circulation battery according to claim 1, further comprising: a lid-shaped guide member fitted to the outer periphery of the cell stack so as to be movable in the stacking direction.   The bag-shaped member is formed of a material that can be freely deformed by internal pressure, and a fluid storage section that communicates with the outside of the cell stack through a pipe in the bag-shaped member, and a pressure that detects the pressure in the bag-shaped member The electrolyte circulation type battery according to claim 2, further comprising a detection unit and a supply / discharge unit that supplies / discharges the fluid in the fluid storage unit to / from the bag-like member.   4. The electrolytic solution battery according to claim 2, wherein the fluid filled in the bag-like member is a gas.   4. The electrolyte circulation type battery according to claim 2, wherein the fluid filled in the bag-like member is a liquid.

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