JP2006351345A - Cell stack of electrolyte circulation type battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell stack of an electrolyte circulation type battery surely preventing contact of a terminal electrode being connected to the cell stack to an electrolyte and preventing loss of input/output function of electric power. <P>SOLUTION: The cell stack 1 is formed by stacking a plurality of cells each comprising a positive electrode 3, a separator 4, and a negative electrode 5 arranged between bipolar plates 21, and has a plate-shaped terminal electrode 6 connected to a positive electrode 3 or a negative electrode 5 and inputting or outputting electricity. A terminal electrode protection part 10 is formed by covering the whole part excluding a part being drawn out to the outside of the cell stack in the terminal electrode 6. A fixing member 7 covering the outer circumferential edge part and one surface through the terminal electrode protection part 10 and fixing the terminal electrode 6 is installed. The terminal electrode 6 is connected to the positive electrode or the negative electrode through the terminal electrode protection part 10. The outer circumferential edge part on the surface on the connection side with the positive/negative electrodes of the terminal electrode protection part 10 is bonded to the fixing member 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, a plurality of cells configured by disposing a positive electrode, a diaphragm, and a negative electrode between bipolar plates are stacked, and a plate-like terminal electrode connected to the positive electrode or the negative electrode for input / output of electricity is provided. It is related with the cell laminated body of the electrolyte circulation type battery which has.

  As an electrolyte circulation type battery, for example, a redox flow battery is known. As shown in the operation principle diagram of FIG. 8, 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.

  For each electrode electrolyte, a solution of ions such as vanadium ions whose valence changes is used, and the electrolyte is circulated by pumps 105A and 105B, and charged along with the valence change reaction of ions in the positive electrode 102 and the negative electrode 103. 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. This cell laminate uses a plurality of diaphragms, bipolar plates, positive electrodes, and negative electrodes. By stacking bipolar plates, positive electrodes, diaphragms, and negative electrodes in this order, positive electrodes, diaphragms, and negative electrodes are placed between the bipolar plates. A plurality of arranged cells are formed.

  The bipolar plate has an outer peripheral edge fixed to an intermediate frame formed of an insulating synthetic resin. The positive electrode and the negative electrode are formed smaller than the area of the inner peripheral portion of the intermediate frame, and the diaphragm is formed larger than the area of the inner peripheral portion of the intermediate frame. When the intermediate frames are stacked, the outer peripheral edge of the diaphragm is sandwiched between the intermediate frames, and a positive electrode or a negative electrode is disposed between the bipolar plate and the diaphragm.

  Further, in the cell laminate, generally, bipolar plates are arranged at both ends in the stacking direction of the cell stack, and terminal electrodes for inputting and outputting electricity to the electrolyte in the cell outside the bipolar plates at the ends in the stacking direction. Is provided.

  Usually, the terminal electrode is formed of a copper plate-like member, and is fixed to a plate-like fixing member formed of an insulating synthetic resin so that one surface of the terminal electrode is exposed. The fixing member is generally a fixed plate that covers one surface of the terminal electrode, an end frame that covers the outer peripheral edge of the other surface of the terminal electrode, and a frame shape that is disposed between the fixed plate and the end frame. And spacers.

  A part of the outer peripheral edge of the terminal electrode is drawn out of the fixing member, and an external terminal is connected to this lead-out part. In order to fix the terminal electrode to the fixing member, first, the outer peripheral edge of the bipolar plate having a size covering the entire surface of the terminal electrode is bonded and fixed to the end frame. Then, the end frame and the spacer are fixed so that the terminal electrode is interposed between the end frame to which the bipolar plate is fixed and the fixed plate, and the spacer and the fixed plate are fixed. The terminal electrode is fixed to the fixing member in a state where the terminal electrode is entirely covered with the end frame, the bipolar plate, the fixing plate, and the spacer except for the lead portion.

  By overlapping the intermediate frame that fixes the bipolar plate and the diaphragm and the end frame that fixes the terminal electrode and the bipolar plate, cells separated by the bipolar plate and the diaphragm are formed inside each frame. Is filled with an electrolyte solution.

JP 2002-367658 A

  In the above-described redox flow battery, since a large amount of electric energy is taken in and out, a material having a high electric conductivity is required as a material constituting the terminal electrode, and the hole forming property for connecting the cable is also good. Since a material capable of obtaining a desired strength is required, a copper terminal electrode is usually used.

  However, when the copper terminal electrode comes into contact with the electrolytic solution, it is dissolved in the electrolytic solution. In particular, the positive electrode is rapidly dissolved by the battery reaction.

  Therefore, conventionally, a terminal plate is not directly brought into contact with the positive electrode or the negative electrode into which the electrolytic solution has been permeated, but a bipolar plate is disposed between the terminal electrode and the positive electrode or the negative electrode, and the outside of the bipolar plate is arranged. The terminal electrode is isolated from the electrolyte by adhering the peripheral edge to the end frame with a solvent. With this configuration, the electrolyte supplied to the positive electrode or the negative electrode is prevented from flowing into the terminal electrode arrangement space surrounded by the end frame, the bipolar plate, the spacer, and the fixed plate.

  However, in the conventional redox flow battery, the outer peripheral edge of the bipolar plate is adhered and sealed to the end frame to prevent the electrolyte from flowing out to the terminal electrode side. The length of the outer peripheral edge of the plate) becomes very large. When the seal area is increased in this way, the probability that seal leakage will occur inevitably increases.

  Furthermore, the bipolar plate used for the redox flow battery is usually made of plastic carbon, and the end frame is made of vinyl chloride resin (PVC). Since plastic carbon and PVC have different coefficients of thermal expansion, when the bipolar plate is bonded to the end frame, if the temperature of the cell stack increases or decreases, the difference in the coefficient of thermal expansion causes a shift in the bonded portion of the bipolar plate, resulting in the bipolar There is a possibility that seal leakage may occur at the bonded portion between the plate and the end frame.

  Thus, when a seal leak occurs and the electrolytic solution comes into contact with the terminal electrode, the copper terminal electrode is dissolved in the electrolytic solution and the power input / output function is lost.

  Accordingly, the present invention provides a cell laminate of an electrolyte circulation type battery that reliably prevents contact of the terminal electrode connected to the cell laminate with the electrolyte and does not lose the power input / output function. For the purpose.

  The cell stack of the electrolyte circulation type battery according to the present invention includes a plurality of cells configured by disposing a positive electrode, a diaphragm, and a negative electrode between bipolar plates, and is connected to the positive electrode or the negative electrode to be electrically connected. The object is achieved by having a plate-like terminal electrode for inputting and outputting and further having the following configuration.

  The cell laminate of the present invention comprises a terminal electrode protection part formed by covering the whole of the terminal electrode with a conductive resin having an electrolyte solution resistance, except for a portion drawn out of the cell laminate. A fixing member for fixing the terminal electrode, covering the outer peripheral edge of the terminal electrode and one surface through the portion. And while connecting a terminal electrode to a positive electrode or a negative electrode via a terminal electrode protection part, the outer peripheral edge part of the surface by the side of the terminal electrode protection part with the positive electrode or negative electrode is adhere | attached on a fixing member. As will be described later, when the fixing member is composed of a fixing plate, a spacer, and an end frame, the outer peripheral edge of the terminal electrode protection unit is bonded to the end frame.

  The plate-like terminal electrode includes a main body having substantially the same area as the bipolar plate, and a lead portion continuously extended from a part of the outer peripheral edge of the main body and connected to an external terminal. It is preferable that The terminal electrode is preferably formed of a copper plate having excellent electrical conductivity.

  As described above, the terminal electrode protection part that covers the terminal electrode is formed of a conductive resin having an electrolytic solution resistance, and the conductive resin is, for example, the same as the resin that forms the bipolar plate of the intermediate frame. It is preferable to use conductive plastic carbon.

  The terminal electrode protection portion is formed so as to cover all of the main body portion of the terminal electrode and a portion covered with the fixing member in the lead portion extending from the main body portion. The terminal electrode protection part can be integrated with the terminal electrode by injection molding so that the terminal electrode serves as a core and covers the entire main body part of the terminal electrode and a part of the lead part. Also, two conductive resin sheets are prepared so as to have an area larger than the area of the terminal electrode along the shape of the terminal electrode, and hot pressing is performed with the terminal electrode sandwiched between the conductive resin sheets. Then, the terminal electrode and the terminal electrode protection part may be integrated.

  The fixing member fixes the terminal electrode covered with the terminal electrode protection portion, covers the entire one surface of the terminal electrode and the outer peripheral edge portion, and the positive electrode or the negative electrode can be disposed on the other surface. Configured as follows. For example, a fixing plate that covers one surface of the terminal electrode, an end frame that covers the outer peripheral edge of the other surface of the terminal electrode, and a frame-shaped spacer that is disposed between the fixing plate and the end frame. A fixing member can be comprised. Further, the fixing member can be constituted by a fixing plate and an end frame without providing a spacer.

  Each of the fixing plate, the end frame, and the spacer is formed so that the outer shape thereof is the same as the outer shape of the intermediate frame. The end frame is formed so that the inner periphery of the end frame is smaller than the outer periphery of the terminal electrode so that the terminal electrode protector contacts the frame surface. In addition, the spacer forms an inner peripheral portion so that the terminal electrode covered with the terminal electrode protection portion fits in the frame.

  When the fixing member is constituted by a fixing plate, a spacer, and an end frame, the end frame and the terminal electrode protection unit are bonded with an adhesive, the end frame and the spacer are bonded with an adhesive, The terminal electrode covered with the terminal electrode protection part can be fixed to the fixing member by adhering the fixing plate to the fixing plate.

  In the present invention, the terminal electrode protection part that covers the terminal electrode replaces the conventional bipolar plate provided between the terminal electrode and the positive electrode or the negative electrode, and the terminal electrode is connected to the positive electrode or the negative electrode via the terminal electrode protection part. Contact the electrode.

  In the present invention, a plurality of cells are stacked, and a cell stack is formed by stacking a fixing member on which terminal electrodes are fixed on an intermediate frame so as to be in contact with a positive electrode or a negative electrode located at an end of the cell in the stacking direction. Form. By forming the cell stack in this way, the positive electrode or negative electrode on the outer side in the stacking direction is arranged in a space surrounded by the intermediate frame, the fixing member, and the terminal electrode protection part, and this space is filled with the electrolyte. In addition, the terminal electrode is connected to the positive electrode or the negative electrode via the terminal electrode protection part.

  In the present invention, since the terminal electrode is entirely covered with a conductive resin having an electrolytic solution resistance except for the portion exposed to the outside, the terminal electrode does not come into contact with the electrolytic solution. Furthermore, since the terminal electrode protection part adhere | attaches the outer periphery part of the surface at the side which contacts electrolyte solution to a fixing member, electrolyte solution is between a terminal electrode protection part and a fixing member (for example, a terminal electrode protection part is , The fixed plate, the spacer, and the portion in contact with the end frame).

  Further, if the terminal electrode protection portion is formed so as to protrude from the fixing member at the terminal electrode lead-out portion, a gap is generated between the terminal electrode protection portion and the fixing member, and the fixing member Even if the electrolyte solution flows out from the position of the lead-out portion, the electrolyte solution can be discharged without contacting the terminal electrode with the electrolyte solution.

  By the way, in the structure of the conventional cell laminated body, the copper constituting the terminal electrode, the plastic carbon constituting the bipolar plate, and the PVC constituting the fixing member (fixing plate, spacer, end frame) have a thermal expansion coefficient and The stiffness was different. Due to this difference in characteristics, when stress is concentrated on a part of the frame when the frames are stacked and tightened, there is a risk that the frame on which the terminal electrode is fixed will crack.

  Therefore, in the present invention, it is preferable to form a plurality of holes in the main body of the terminal electrode. In order to obtain the necessary electrical conductivity of the terminal electrode, to reduce the rigidity of the terminal electrode, and to improve the adhesion force with the conductive resin, the hole has a ratio of the opening area of the terminal electrode. It is preferable to form so as to be 10 to 90% of the area. By forming the hole in the terminal electrode in this manner, the rigidity of the terminal electrode is reduced as compared with the case where the hole is not formed.

  When a plurality of holes are formed in the terminal electrode, the terminal electrode protection portion is formed by injection molding or hot pressing so that the conductive resin is molded in the holes, and the terminal electrode And the terminal electrode protection part are integrated. In this case, since the conductive resin portions formed on both surfaces of the terminal electrode are joined to the terminal electrode protection part via the hole of the terminal electrode, the terminal electrode and the terminal electrode protection part can be firmly integrated.

  Moreover, since the terminal electrode protection part is integrated through the hole of the terminal electrode, the strength of the terminal electrode protection part can be increased.

  The cell laminate of the present invention is connected to, for example, a positive electrode tank and a negative electrode tank that store electrolyte solutions of respective electrodes via pipes, and these cell laminates and tanks constitute an electrolyte circulation type battery. The And charging / discharging is performed by a cell laminated body by connecting the terminal electrode provided in a cell laminated body to load or an electric power grid | system. 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.

  According to the cell stack of the electrolyte circulation type battery of the present invention, since the terminal electrode is almost entirely covered with the conductive resin, the function of the terminal electrode is maintained without being in contact with the electrolyte. Can do. Furthermore, since the outer peripheral edge part of the terminal electrode protection part in contact with the electrolytic solution is adhered to the fixing member, the electrolytic solution can be prevented from flowing out from between the terminal electrode protection part and the fixing member.

  In addition, since the terminal electrode and the terminal electrode protector can always be brought into contact with each other, the electrical resistance can be reduced as compared with the conventional case where the terminal electrode and the bipolar plate are brought into contact with each other by the clamping force of the frame. Can be stabilized.

  In addition, when the hole is formed in the terminal electrode, the rigidity of the terminal electrode can be reduced as compared with the case where the hole is not formed, and when the terminal electrode is fixed to the fixing member, the fixing member is not cracked due to the difference in rigidity. It can be lost.

  Furthermore, when a hole is formed in the terminal electrode and the conductive resin is also filled in this hole, the terminal electrode and the terminal electrode protection part can be integrated so that the electric resistance is more stable than in the past. Can be made.

  Hereinafter, an embodiment of a cell laminate of the electrolytic solution circulation type battery of the present invention will be described. The electrolyte circulation type battery used in the present embodiment is a redox flow battery.

(overall structure)
FIG. 1 is a schematic configuration diagram of a cell laminate of an electrolyte circulation battery according to the present invention as viewed from above. The cell laminate 1 includes a plurality of intermediate frames 2 having a bipolar plate 21, a positive electrode 3, a diaphragm 4, and a negative electrode 5. In the cell laminate 1, these members are laminated so as to have the positive electrode 3, the diaphragm 4, and the negative electrode 5 between the intermediate frames 2. Then, a fixing member 7 in which the positive electrode 3 is arranged at one end in the stacking direction of these members and the negative electrode 5 is arranged at the other end, and the terminal electrode 6 is fixed to face the positive electrode 3 or the negative electrode 5 Is placed. Further, the supply / discharge plate 8 is disposed outside the fixing member 7 in the stacking direction, and the cell stack 1 is configured by tightening each member in the stacking direction by the tightening mechanism 9 having the end plate 91.

  A unit cell of the cell stack is configured by disposing a positive electrode 3, a diaphragm 4, and a negative electrode 5 between two intermediate frames 2. Then, the outer peripheral edge of the diaphragm 4 is sandwiched between the frame portions 22 of the two intermediate frames 2, and the positive electrode 3 or the negative electrode 5 is disposed between the diaphragm 4 and the bipolar plate 21 of the intermediate frame 2. I am letting.

(Intermediate frame)
The intermediate frame 2 includes a frame part 22 and a bipolar plate 21 fixed inside the frame part 22. The frame portion 22 is a frame-like body made of a synthetic resin mainly composed of vinyl chloride. On the other hand, the bipolar plate 21 is a rectangular plate made of conductive plastic carbon containing graphite.

  As shown in FIG. 2, a plurality of manifolds 23 are formed on the long side of the frame portion 22 in the frame portion 22 of the intermediate frame 2. These manifolds 23 are distinguished into those used for the positive electrode electrolyte and those used for the negative electrode electrolyte. When a plurality of intermediate frames are stacked, the manifolds 23 of the respective intermediate frames are in a continuous state, and an electrolyte flow path extending in the stacking direction is formed by the manifolds 23. Furthermore, although not shown in the figure, a flow groove that connects one manifold and the inner peripheral surface of the frame portion is formed on the surface of the frame portion 22.

  In the electrolyte circulation type battery of the present embodiment, the positive electrode electrolyte is supplied from the positive electrode electrolyte manifold to the inner peripheral surface of the frame portion 22 through the positive electrode flow groove, and the positive electrode electrolysis supplied to the inner peripheral surface The liquid is discharged from another positive electrode electrolyte manifold through another positive electrode flow groove. The negative electrode electrolyte is supplied from the negative electrode electrolyte manifold to the inner peripheral surface of the frame portion 22 via the negative electrode flow groove, and the negative electrode electrolyte supplied to the inner peripheral surface is separated from the inner surface. It discharges | emits from another manifold for negative electrode electrolyte solutions through the distribution groove for negative electrodes.

  The intermediate frame 2 is configured such that the frame portions 22 of the intermediate frame 2 are overlapped with each other through a seal member such as packing, with the positive electrode 3, the diaphragm 4, and the negative electrode 5 disposed between the intermediate frames 2. . At this time, the outer peripheral edge of the diaphragm 4 is sandwiched between the two frame parts 22, and the positive electrode 3 or the negative electrode 5 is placed between the bipolar plate 21 and the diaphragm 4 in the frame of the frame part 22. Arrange.

(Positive electrode and negative electrode)
As described above, since the positive electrode 3 and the negative electrode 5 are disposed between the intermediate frames 2, the positive electrode 3 is disposed on one surface of the bipolar plate 21, and the negative electrode 5 is disposed on the other surface. Will be. Usually, carbon felt is used for the positive electrode 3 and the negative electrode 5. The size of the electrodes 3 and 5 is set to a size corresponding to a rectangular space formed in the frame portion 22 of the intermediate frame 2. The electrodes 3 and 5 may be bonded to the bipolar plate 21 with an adhesive, or the electrodes 3 and 5 may be brought into contact with the bipolar plate 21 by a clamping force of a clamping mechanism 9 described later. Also good.

(diaphragm)
As the diaphragm 4, an ion exchange membrane is used. As the material, an ion exchange resin containing vinyl chloride, fluororesin, polyethylene, polypropylene or the like can be used. The diaphragm 4 has an area substantially equal to that of the intermediate frame 2, an area having an outer peripheral edge smaller than the outer peripheral edge of the frame part 22 and larger than an inner peripheral edge of the frame part 22, or an area larger than the outer peripheral edge of the frame part 22. It can have. When the diaphragm 4 has a portion that overlaps with the manifold formed in the frame portion 22, a through hole is formed at a location facing the manifold. The diaphragm 4 retains the shape of the diaphragm 4 by sandwiching the outer peripheral edge portion thereof with the frame portion 22.

(Terminal electrode)
The terminal electrode 6 is formed of a copper plate member and is fixed to the fixing member 7. As shown in FIGS. 3 and 4, the terminal electrode 6 is continuous from a main body 61 having substantially the same size as the bipolar plate 21 fixed to the intermediate frame 2 and a part of the outer peripheral edge of the main body 61. And a drawer part 62 to which an external terminal is connected.

  Further, a plurality of holes 63 are formed in the body portion 61 of the terminal electrode 6 in order to reduce the rigidity of the terminal electrode 6. The hole 63 is formed so that the ratio of the opening area is 10 to 90% with respect to the area of the terminal electrode. In the drawer portion 62, an attachment hole 64 for connecting an external terminal is formed.

  As shown in FIG. 5, the terminal electrode 6 is entirely covered with a conductive resin except for the portion where the mounting hole 64 is formed, and the terminal electrode protection portion 10 is formed with this conductive resin. Specifically, the entire outer surface of the body portion 61 of the terminal electrode 6 and the portion excluding the portion to which the external terminal is connected in the lead-out portion 62 are covered with a conductive resin without a gap to form the terminal electrode protection portion 10 is doing. In the present embodiment, as shown in FIG. 2, the portion formed in the lead-out portion 62 of the terminal electrode protection portion 10 protrudes from the fixing member 7 when the terminal electrode 6 is fixed to the fixing member 7. To form.

  Further, the terminal electrode protection part 10 is made of the same conductive plastic carbon as the resin forming the bipolar plate 21 of the intermediate frame 2.

  Then, in order to form the terminal electrode protection part 10 on the terminal electrode 6, the terminal electrode 6 is used as a core, and a conductive resin is injected so as to cover the entire main body part 61 of the terminal electrode 6 and a part of the lead part 62. The terminal electrode 6 and the terminal electrode protection part 10 are integrated by molding. In addition, two conductive resin sheets are prepared so as to have an area larger than the area of the terminal electrode 6 along the shape of the terminal electrode 6, and the terminal electrode 6 is sandwiched between the conductive resin sheets. The terminal electrode 6 and the terminal electrode protection part 10 may be integrated by hot pressing.

  In the present embodiment, since a plurality of holes 63 are formed in the terminal electrode 6, as shown in FIGS. 6 and 7, an injection molding or heat treatment is performed so that the conductive resin is also molded in the holes 63. Press work. The terminal electrode protection unit 10 is bonded to the conductive resin portions formed on both surfaces of the terminal electrode 6 through the holes 63 of the terminal electrode 6, so that the terminal electrode 6 and the terminal electrode protection unit 10 are firmly integrated. Can be

  A terminal electrode 6 is fixed to the fixing member 7 via a terminal electrode protection part 10. As shown in FIGS. 2, 6, and 7, the fixing member 7 includes a fixing plate 71 disposed on one surface side of the terminal electrode 6 and an end frame 72 disposed on the other surface of the terminal electrode 6. And a frame-like spacer 73 disposed between the fixing plate 71 and the end frame 72.

  Each of the fixing plate 71, the end frame 72, and the spacer 73 is formed so that the outer shape thereof is the same as the outer shape of the intermediate frame 2. The fixed plate 71 has a rectangular plate shape that covers the entire one surface of the terminal electrode 6. The end frame 72 is formed in a frame shape in which the size of the inner peripheral portion of the end frame 72 is smaller than the outer peripheral edge of the terminal electrode 6 so that the terminal electrode protection portion contacts the frame surface. The spacer 73 is formed in a frame shape having an inner peripheral portion of a size into which the terminal electrode 6 covered with the terminal electrode protection portion 10 is fitted.

  In order to fix the terminal electrode 6 to the fixing member 7, first, the end frame 72 serving as the electrolyte sealing surface and the terminal electrode protection part 10 are fixed with an adhesive. Then, a spacer 73 is arranged on the outer periphery of the terminal electrode 6 covered with the terminal electrode protection part 10, and the spacer 73 is fixed to the end frame 72 with an adhesive. Finally, the fixing plate 71 is fixed to the spacer 73 with an adhesive. The terminal electrode 6 is fixed to the fixing member 7 in a state where the outer peripheral edge is sandwiched between the fixing plate 71 of the fixing member 7, the end frame 72, and the spacer 73.

  In this way, by fixing the terminal electrode 6 to the fixing member 7, the terminal electrode 6 is connected to the entire one surface of the terminal electrode 6 and the outer peripheral edge with the fixing member 7 via the terminal electrode protection part 10. It will be covered.

  In the present embodiment, a plurality of cells are stacked, and as shown in FIG. 2, the fixing member to which the terminal electrode 6 is fixed so as to be in contact with the positive electrode 3 or the negative electrode 5 located at the end in the stacking direction of the cells. Cell stack 1 is formed by superposing 7 on intermediate frame 2. The positive electrode 3 or the negative electrode 5 on the outer side in the stacking direction is disposed in a space surrounded by the diaphragm 4 provided between the intermediate frame 2 and the fixing member 7, the fixing member 7, and the terminal electrode protection part 10. The space is filled with electrolyte. Then, the terminal electrode 6 is connected to the positive electrode 3 or the negative electrode 5 through the terminal electrode protection unit 10.

  Since the terminal electrode 6 is entirely covered with the conductive resin by the terminal electrode protection unit 10 except for the portion exposed to the outside, the terminal electrode 6 is not dissolved in the electrolyte when the cell laminate 1 is formed. It is possible to reliably prevent the terminal electrode 6 from being dissolved in the electrolytic solution. Further, since the terminal electrode protection part 10 is bonded to the end frame 72 of the fixing member 7 on the surface in contact with the electrolytic solution, the electrolytic solution is externally provided between the terminal electrode protection part 10 and the fixing member 7. Can be prevented from leaking.

  In addition, since the terminal electrode protection part 10 is formed so as to protrude outside the fixing member 7 in the lead-out part 62 of the terminal electrode 6, there is a gap between the terminal electrode protection part 10 and the fixing member 7. Therefore, even if the electrolytic solution flows out from the position of the extraction portion 62 of the fixing member 7, the electrolytic solution does not contact the terminal electrode 6. The leaked electrolytic solution falls along the fixing member 7.

  Also, since the hole 63 is formed in the terminal electrode 6, the rigidity of the terminal electrode 6 can be reduced compared to a plate-shaped terminal electrode in which no conventional hole is formed, and the terminal electrode 6 is fixed to the fixing member 7. When it does, the crack of the fixing member resulting from a difference in rigidity can be eliminated.

  Furthermore, since the hole 63 is formed in the terminal electrode 6 and the hole 63 is also filled with the conductive resin, the terminal electrode 6 and the terminal electrode protection part 10 can be integrated, so that the electric resistance has been improved. Compared to, it can be stabilized in the long term.

  A manifold 74 is also formed at the same position as the manifold formed on the frame portion 22 of the intermediate frame 2 on the fixing plate 71, the spacer 73, and the end frame 72 of the fixing member 7. The end frame 72 is formed with a flow groove 75 that allows the manifold 74 and the inner peripheral surface to communicate with each other.

(Supply / discharge plate)
As shown in FIG. 1, the supply / discharge plate 8 is disposed on the outer side in the stacking direction than the fixing member 7 to which the terminal electrode 6 in the cell stack 1 is fixed. Although not shown, the supply / discharge plate 8 has an electrolyte flow passage that connects each electrolyte tank and the manifold 23 of the intermediate frame 2 to supply and discharge the electrolyte to and from the manifold. A pipe 81 is attached to the electrolyte flow passage formed in the supply / discharge plate 8, and this pipe 81 is connected to the electrolyte tank.

(Tightening mechanism)
As shown in FIG. 1, the tightening mechanism 9 includes an end plate 91 disposed outside the both supply and discharge plates 8 superimposed on the cell stack, a plurality of connecting rods 92 that connect the end plates 91, A nut 93 is mounted on both ends of the connecting rod 92, and a spring 94 is inserted through the connecting rod 92 and disposed between the end plate 91 and the nut 93.

  The end plate 91 is a lattice plate having a larger area than the supply / discharge plate 8 and the intermediate frame 2. Further, a plurality of insertion holes through which the connecting rod 92 is inserted are formed on the outer peripheral portion of the end plate 91 larger than the supply / discharge plate 8 and the intermediate frame 2. The connecting rod 92 is male threaded to screw nuts 93 into both ends thereof.

  By arranging end plates 91 on the outside of both supply / discharge plates 8 superimposed on the cell stack, connecting these end plates 91 with connecting rods 92, and tightening nuts 93, end plates 91, fixing members 7, the cell stack 1 is configured by pressing the supply / discharge plate 8, the intermediate frame 2, the positive electrode 3, the diaphragm 4, and the negative electrode 5 together. The spring 94 attached to the connecting rod 92 is used to absorb thermal expansion and contraction of the members constituting the cell stack 1.

  The operating principle of the cell laminate 1 configured as described above is the same as that described with reference to the redox flow battery shown in FIG. 8, 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.

  According to this embodiment, since the entire terminal electrode 6 can be covered with the terminal electrode protection part 10 formed of conductive resin in the fixing member 7, the terminal electrode 6 comes into contact with the electrolytic solution. Therefore, the function of the terminal electrode 6 can be maintained.

  In the above-described embodiment, the plurality of holes 63 are formed in the terminal electrode 6. However, the terminal electrode may be covered with a conductive resin to form the terminal electrode protection part without forming the hole.

  Furthermore, in this embodiment, the terminal electrodes are provided only at both ends in the stacking direction of the cell stack, but a plurality of subcell stacks having terminal electrodes provided at both ends in the stacking direction of a plurality of cells are formed, and these subcell stacks are formed. Further, the cell stack may be configured by stacking. In this case, the terminal electrode is in a state where a plurality of pairs of terminal electrodes are provided.

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

It is a schematic block diagram of the cell laminated body used for the redox flow battery which concerns on embodiment of this invention. It is a disassembled perspective view which shows the assembly | attachment state of the terminal electrode fixed to the fixing member in the cell laminated body of this embodiment, and the positive electrode laminated | stacked on this terminal electrode, a diaphragm, a negative electrode, and an intermediate | middle frame. It is a top view of the terminal electrode fixed to the fixing member in this embodiment. It is a top view of the terminal electrode in this embodiment. It is a top view which shows the state in which the terminal electrode protection part was formed in the terminal electrode in this embodiment. It is the XX sectional view taken on the line in FIG. FIG. 4 is a sectional view taken along line YY in FIG. 3. It is explanatory drawing of the principle of operation of a redox flow battery.

Explanation of symbols

1 cell laminate
2 Intermediate frame
21 Bipolar plate 22 Frame 23 Manifold
3 Positive electrode 4 Diaphragm 5 Negative electrode
6 terminal electrode
61 Body 62 Drawer 63 Hole 64 Mounting hole
7 Fixing member
71 Fixing plate 72 End frame 73 Spacer
74 Manifold 75 Flow channel
8 Supply / discharge plate
81 pipe
9 Tightening mechanism
91 End plate 92 Connecting rod 93 Nut
94 Spring
10 Terminal electrode protection
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

Claims (4)

Electrolyte circulation having a plate-shaped terminal electrode that is connected to the positive electrode or the negative electrode and inputs and outputs electricity while a plurality of cells configured by arranging a positive electrode, a diaphragm, and a negative electrode between the bipolar plates are stacked In a cell stack of type batteries,
A terminal electrode protection part formed by covering the whole of the terminal electrode except for the part drawn out of the cell stack with a conductive resin having an electrolytic solution resistance;
A fixing member for fixing the terminal electrode, covering the outer peripheral edge of the terminal electrode and one surface through the terminal electrode protection unit;
While connecting the terminal electrode to the positive electrode or the negative electrode through the terminal electrode protection part,
A cell stack of an electrolyte circulating battery, characterized in that an outer peripheral edge portion of a surface of a terminal electrode protection portion on a side connected to a positive electrode or a negative electrode is bonded to a fixing member.   A plurality of holes are formed in a portion of the terminal electrode covered with the terminal electrode protection part, and the terminal electrode and the terminal electrode protection part are integrated so as to have a conductive resin in the holes. The cell laminate of the electrolyte circulation type battery according to claim 1, wherein   The cell laminate of the electrolyte circulation type battery according to claim 2, wherein the ratio of the opening area of the holes is 10 to 90% of the area of the terminal electrode.   The fixing member includes a fixing plate that covers one surface of the terminal electrode, an end frame that covers the outer peripheral edge of the other surface of the terminal electrode, and a frame-like shape that is disposed between the fixing plate and the end frame. The cell laminate of the electrolyte circulation type battery according to any one of claims 1 to 3, further comprising a spacer.

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