JP6536867B1 - Bipolar plate, cell frame, cell stack, and redox flow battery - Google Patents

Abstract

  The bipolar plate is provided with a flow path through which the electrolyte flows, and the flow path is an inlet for the electrolyte on the lower side of the bipolar plate, an outlet for the electrolyte on the upper side of the bipolar plate, and the inlet. And a discharge groove portion connected to the discharge port, wherein the introduction groove portion and the discharge groove portion have a locally small cross-sectional area, and a communication portion connecting the inlet and the discharge port, Alternatively, it has a closed end that divides the introduction groove and the discharge groove from each other, and the introduction groove is directed toward the lower side of the bipolar plate halfway in the longitudinal direction from the introduction port toward the tip of the introduction groove. A bipolar plate comprising: a lower bending portion to be bent; and an introduction liquid reservoir for storing an electrolytic solution on the tip side of the introduction groove portion with respect to the lower bending portion.

Description

  The present invention relates to bipolar plates, cell frames, cell stacks, and redox flow batteries.

  Patent documents 1 to 4 mainly include battery cells including a positive electrode supplied with a positive electrode electrolyte, a negative electrode supplied with a negative electrode electrolyte, and a diaphragm interposed between the positive electrode and the negative electrode. A redox flow battery is disclosed which performs charging and discharging by supplying the electrolyte solution of each electrode to the electrode of each electrode as a component. The battery cell is configured by arranging a set of cell frames so as to sandwich a laminate of a positive electrode, a diaphragm, and a negative electrode. The cell frame includes a bipolar plate on which positive and negative electrodes are respectively disposed on the front and back surfaces, and a frame provided on an outer periphery of the bipolar plate.

  Patent Documents 1 to 4 disclose a bipolar plate provided with a plurality of grooves through which an electrolytic solution flows in order to sufficiently spread the electrolytic solution to the electrodes of the respective electrodes in the battery cell.

JP, 2015-122230, A JP, 2015-122231, A Unexamined-Japanese-Patent No. 2015-138771 JP, 2015-210849, A

The bipolar plate according to the present disclosure is
A bipolar plate, which is disposed between a positive electrode and a negative electrode of a redox flow battery, and has a flow path through which an electrolytic solution flows on the opposite surface facing at least one of the positive electrode and the negative electrode.
When the lower side in the vertical direction when the bipolar plate is disposed at a predetermined position of the redox flow battery so that the facing surface is along the vertical direction is the lower side of the bipolar plate and the upper side in the vertical direction is the upper side of the bipolar plate ,
The flow path is
An electrolyte inlet on the lower side of the bipolar plate,
An electrolyte outlet on the upper side of the bipolar plate,
An introduction groove connected to the introduction port;
And a discharge groove connected to the discharge port;
The introduction groove portion and the discharge groove portion are
A communication portion having a locally small cross-sectional area and communicating the inlet and the outlet,
Or a closed end that separates the introduction groove and the discharge groove from each other,
The introduction groove portion is
A lower bending portion that bends toward the lower side of the bipolar plate midway in the longitudinal direction from the introduction port toward the tip of the introduction groove portion;
And an introducing liquid reservoir for storing an electrolytic solution on the front end side of the introducing groove portion with respect to the lower bent portion.

  A cell frame according to the present disclosure includes the bipolar plate according to the present disclosure, and a frame provided on an outer periphery of the bipolar plate.

  A cell stack according to the present disclosure includes the cell frame according to the above-described present disclosure.

  The redox flow battery according to the present disclosure includes the cell stack according to the above-described present disclosure.

FIG. 2 is an explanatory diagram of an operation principle of the redox flow battery according to Embodiment 1. FIG. 1 is a schematic configuration view of a redox flow battery according to Embodiment 1. FIG. 2 is a schematic configuration diagram of a cell stack according to Embodiment 1. FIG. 1 is a schematic plan view showing a bipolar plate according to Embodiment 1; FIG. 7 is a schematic plan view showing a bipolar plate according to Embodiment 2. FIG. 10 is a schematic plan view showing a bipolar plate according to a third embodiment. FIG. 10 is a schematic plan view showing a bipolar plate according to a fourth embodiment. FIG. 14 is a schematic plan view showing a dipole plate according to Embodiment 5. FIG. 16 is a schematic plan view showing a bipolar plate according to a sixth embodiment.

[Problems to be solved by the present disclosure]
When a power failure occurs in the power supply source, it is desirable to start the battery without power supply from the external system.

  The supply of the electrolytic solution of each electrode to the positive electrode and the negative electrode is typically performed from the lower side to the upper side of the electrode of each electrode by a pump operation. Therefore, when the pump is stopped due to a power failure, the liquid level of the electrolytic solution in the battery cell is lowered due to its own weight, and it is not possible to maintain the state in which the electrode of each electrode is impregnated with the electrolytic solution.

  In the bipolar plate having grooves, during operation of the redox flow battery, the electrolyte supplied into the battery cells moves between the grooves along the flow along each groove and across ridges located between adjacent grooves. And the electrolyte can be distributed to the electrodes of each pole. However, even if the bipolar plate has a groove, if the pump is stopped due to a power failure, the electrolyte in the groove is discharged to the outside of the battery cell from the inlet of the electrolyte by its own weight.

  Therefore, an object of the present disclosure is to provide a bipolar plate capable of storing an electrolytic solution inside a battery cell even during a power failure. In addition, another object of the present disclosure is to provide a cell frame including the bipolar plate, a cell stack including the cell frame, and a redox flow battery including the cell stack.

[Effect of the present disclosure]
According to the present disclosure, it is possible to provide a bipolar plate, a cell frame, a cell stack, and a redox flow battery capable of storing an electrolytic solution inside a battery cell even at the time of a power failure.

Description of the embodiment of the present invention
First, the contents of the embodiment of the present invention will be listed and described.

(1) The bipolar plate according to the embodiment of the present invention is
A bipolar plate, which is disposed between a positive electrode and a negative electrode of a redox flow battery, and has a flow path through which an electrolytic solution flows on the opposite surface facing at least one of the positive electrode and the negative electrode.
When the lower side in the vertical direction when the bipolar plate is disposed at a predetermined position of the redox flow battery so that the facing surface is along the vertical direction is the lower side of the bipolar plate and the upper side in the vertical direction is the upper side of the bipolar plate ,
The flow path is
An electrolyte inlet on the lower side of the bipolar plate,
An electrolyte outlet on the upper side of the bipolar plate,
An introduction groove connected to the introduction port;
And a discharge groove connected to the discharge port;
The introduction groove portion and the discharge groove portion are
A communication portion having a locally small cross-sectional area and communicating the inlet and the outlet,
Or a closed end that separates the introduction groove and the discharge groove from each other,
The introduction groove portion is
A lower bending portion that bends toward the lower side of the bipolar plate midway in the longitudinal direction from the introduction port toward the tip of the introduction groove portion;
And an introducing liquid reservoir for storing an electrolytic solution on the front end side of the introducing groove portion with respect to the lower bent portion.

  The bipolar plate includes an introduction groove and a discharge groove as channels through which the electrolyte flows, and the introduction groove and the discharge groove communicate with each other having a locally small cross-sectional area, or the introduction groove and the discharge groove mutually By providing the divided closed end, the introduction groove and the discharge groove can function as substantially independent grooves. By the introduction groove portion and the discharge groove portion functioning substantially independently, it is possible to form the flow of the electrolytic solution across the ridge portion located between the introduction groove portion and the discharge groove portion during the operation of the redox flow battery, The cell reaction can be promoted by the electrolytic solution crossing the buttocks.

  The bipolar plate has an electrolyte inlet at the lower side of the bipolar plate and an outlet of the electrolyte at the upper side of the bipolar plate. Therefore, when the pump is stopped due to a power failure, the electrolyte in the discharge groove is discharged as it is It can be stored in the ditch. And by providing an introductory liquid storage part in an introductory groove part, when a pump stops by a power failure, a part of electrolyte solution in an introductory groove part can be stored in an introductory liquid reservoir part. Since the electrolyte can be stored in the introduction liquid reservoir in the discharge groove and in the introduction groove, the battery can be started by the stored electrolyte even when the pump is stopped due to a power failure. The operation of the redox flow battery can be enabled by starting the pump by starting the battery. The bipolar plate can store the electrolytic solution in both the discharge groove portion and the introduction groove portion, so that the battery can be started even when the pump is stopped during the discharge operation of the redox flow battery.

  (2) As one mode of the above-mentioned bipolar plate, each of the introduction groove and the discharge groove may include a comb-tooth area which is engaged with each other and disposed to face each other.

  The bipolar plate can form a battery reaction area crossing between the comb teeth in the meshed comb region by the introduction groove portion and the discharge groove portion being engaged with each other and disposed to face each other. The amount of electrolyte crossing the space between the comb teeth is likely to increase as compared with the case where the introduction groove portion and the discharge groove portion are not meshed with each other, and therefore, the cell reaction can be further promoted.

(3) As one form of the above-mentioned bipolar plate provided with a communicating part,
The discharge groove portion is
An upper bent portion which is bent toward the upper side of the bipolar plate midway in the longitudinal direction from the discharge port toward the tip of the discharge groove;
A discharge liquid reservoir for storing an electrolytic solution on the front end side of the discharge groove with respect to the upper bent portion;
The introduction liquid reservoir and the discharge liquid reservoir may be provided in the communication unit.

  The introductory liquid reservoir and the discharge liquid reservoir are communication parts having a locally small cross-sectional area, so that the introductory liquid reservoir and the discharge liquid reservoir are parts other than the introductory liquid reservoir of the introduction groove and the discharge groove The high pressure loss is caused by the parts other than the liquid storage part. The introduction liquid reservoir and the discharge liquid reservoir have a higher pressure loss than the other portions, so that the amount of electrolyte flowing to the introduction liquid reservoir and the discharge liquid reservoir during operation of the redox flow battery can be The amount can be sufficiently smaller than the amount of electrolytic solution flowing to the portion other than the introduction liquid storage portion and the portion other than the discharge liquid storage portion of the discharge groove, and the introduction groove and the discharge groove can function as substantially independent grooves. On the other hand, the introduction groove portion is provided with the introduction liquid reservoir portion, and the discharge groove portion is provided with the discharge liquid reservoir portion, so that when the pump is stopped due to a power failure, part of the electrolyte in the introduction groove portion can be stored in the introduction liquid reservoir portion. The amount of electrolyte stored in the discharge groove can be increased as compared to the case where the discharge liquid reservoir is not provided.

  (4) As one form of the bipolar plate in which the inflow liquid reservoir and the discharge fluid reservoir are provided in the communication portion, the width of the inflow fluid reservoir and the discharge fluid reservoir may be locally narrow.

  According to the above configuration, even when the distance between the introduction groove portion and the discharge groove portion is narrow, the communication portion having a small cross-sectional area can be provided.

  (5) As one form of the bipolar plate in which the introduced liquid reservoir and the discharged liquid reservoir are provided in the communicating portion, the introduced liquid reservoir and the discharged liquid reservoir may be locally shallow. .

  According to the above configuration, the electrode can easily enter the inside of the introduced liquid reservoir and the discharged liquid reservoir, and the electrode can not easily flow through the introduced liquid reservoir and the discharged liquid reservoir by this electrode, and the cross-sectional area of the communication portion Easy to make smaller. Moreover, even when the thickness of the bipolar plate is thin, it is possible to provide a communicating portion having a small cross-sectional area.

  (6) As one form of the above-mentioned bipolar plate in which the introduced liquid reservoir and the discharged liquid reservoir are provided in the communicating portion, a plurality of units in which the inlet and the outlet communicate with each other at the communicating portion Are present independently of one another.

  A plurality of units having a small cross-sectional area and a high pressure loss communication unit in which the inlet and the outlet communicate with each other, and the adjacent units exist independently, so that there is only one inlet and one outlet, The state of charge (sometimes referred to as the charge depth) of the electrolyte stored in the inflow reservoir and the drain reservoir is uniform over the entire bipolar plate as compared to the case where all the units are in communication. Can be

(7) As one form of the above-mentioned bipolar plate,
The discharge groove portion is
An upper bent portion which is bent toward the upper side of the bipolar plate midway in the longitudinal direction from the discharge port toward the tip of the discharge groove;
A discharge liquid reservoir for storing an electrolytic solution on the front end side of the discharge groove with respect to the upper bent portion;
The introduction groove portion and the discharge groove portion are separated from each other,
The introduction liquid reservoir and the discharge liquid reservoir may be engaged with each other and disposed to face each other.

  By providing the discharge groove portion with the discharge liquid storage portion, when the pump is stopped due to a power failure, the amount of electrolytic solution stored in the discharge groove portion can be increased compared to the case where the discharge liquid storage portion is not provided. Since the introduced liquid reservoir and the discharged liquid reservoir are engaged with each other and disposed opposite to each other, it is easy to quickly start the battery by the stored electrolytic solution.

(8) As one form of the above-mentioned bipolar plate, in which the introduction groove portion and the discharge groove portion are separated from each other, and the introductory liquid reservoir portion and the discharge liquid reservoir portion are engaged with each other and arranged to face each other,
The introduction groove portion is
An introduction stem groove along the vertical direction of the bipolar plate;
A plurality of introduction branch grooves extending in a direction intersecting the vertical direction of the bipolar plate midway in the longitudinal direction of the introduction trunk groove;
And an inlet fluid reservoir at the end of the inlet branch groove,
The discharge groove portion is
A discharge trunk groove along the vertical direction of the bipolar plate;
A plurality of discharge branch grooves extending in a direction intersecting the vertical direction of the bipolar plate midway in the longitudinal direction of the discharge trunk groove;
It is possible to provide the discharge liquid reservoir at the tip of the discharge branch groove.

  A plurality of introduced liquid reservoirs are provided along the vertical direction of the introduction groove, and a plurality of discharged liquid reservoirs are provided along the vertical direction of the discharge groove, and the introduced liquid reservoir and the discharged liquid reservoir are engaged with each other and face each other. By being disposed, it is easy to start the battery early by the stored electrolytic solution.

  (9) As one form of the above-mentioned bipolar plate, it is mentioned that the introduction groove and the discharge groove are formed in a spiral shape separated from each other.

  According to the above configuration, it is easy to increase the area where the introduction groove portion and the discharge groove portion are engaged with each other to be opposed to each other, and the electrolyte solution crossing the ridge portion located between the introduction groove portion and the discharge groove portion during operation of the redox flow battery Since it is easy to increase the amount, the battery reaction can be further promoted by the electrolytic solution crossing this ridge.

  (10) A cell frame according to an embodiment of the present invention includes the bipolar plate according to any one of the above (1) to (9), and a frame provided on the outer periphery of the bipolar plate.

  Since the cell frame is provided with the bipolar plate according to the embodiment of the present invention, the electrolytic solution can be stored inside the battery cell even at the time of a power failure, and even if the pump is stopped by the power failure, the stored electrolysis The solution can start the battery.

  (11) A cell stack according to an embodiment of the present invention includes the cell frame described in (10) above.

  Since the cell stack includes the cell frame according to the embodiment of the present invention, the electrolyte can be stored inside the battery cell even at the time of a power failure, and even if the pump is stopped by the power failure, the stored electrolysis is performed. The solution can start the battery.

  (12) A redox flow battery according to an embodiment of the present invention includes the cell stack described in (11) above.

  Since the above-mentioned redox flow battery is provided with the cell stack according to the embodiment of the present invention, the electrolytic solution can be stored inside the battery cell even at the time of power failure, and is stored even when the pump is stopped by the power failure. The electrolytic solution can start the battery.

Details of the Embodiment of the Present Invention
Details of the bipolar plate, the cell frame, the cell stack, and the redox flow battery according to the embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same names.

Embodiment 1
One of the features of the present embodiment is that the bipolar plate is provided with a configuration capable of storing the electrolytic solution inside the battery cell even at the time of a power failure. In the following, first, the basic configurations of the redox flow battery, the cell stack, and the cell frame according to Embodiment 1 will be described with reference to FIGS. 1 to 4, and then, with reference to FIG. The configuration of the bipolar plate provided in the cell frame (cell stack, redox flow battery) will be described in detail.

[RF battery]
As shown in FIG. 1, the redox flow battery (hereinafter referred to as RF battery) 1 typically includes a power generation unit, a load such as an electric power system or a consumer via an AC / DC converter, a substation, etc. Connected to charge the power generation unit as a power supply source and discharge the load as a power consumption target. Examples of the power generation unit include a solar power generator, a wind power generator, and other general power plants.

  The RF battery 1 includes a battery cell 100 separated into a positive electrode cell 102 and a negative electrode cell 103 by a diaphragm 101. The positive electrode cell 102 contains a positive electrode 104 supplied with a positive electrode electrolyte, and the negative cell 103 contains a negative electrode 105 supplied with a negative electrode electrolyte. The positive electrode 104 and the negative electrode 105 are reaction sites where active material ions contained in the supplied electrolytic solution perform a battery reaction. The diaphragm 101 is a thin film member which separates the positive electrode 104 and the negative electrode 105 and transmits predetermined ions.

  A positive electrode circulation mechanism 100P for circulating and supplying the positive electrode electrolyte to the positive electrode cell 102 includes a positive electrode electrolyte tank 106 for storing the positive electrode electrolyte, conduits 108 and 110 for connecting the positive electrode electrolyte tank 106 and the positive cell 102, And a pump 112 provided in the conduit 108 on the upstream side (supply side). A negative electrode circulation mechanism 100N for circulating and supplying the negative electrode electrolyte to the negative electrode cell 103 includes a negative electrode electrolyte tank 107 for storing the negative electrode electrolyte, conduits 109 and 111 for connecting the negative electrode electrolyte tank 107 and the negative cell 103, And a pump 113 provided in the conduit 109 on the upstream side (supply side).

  The positive electrode electrolyte is supplied from the positive electrode electrolyte tank 106 to the positive electrode 104 via the conduit 108 on the upstream side, and returned from the positive electrode 104 to the positive electrolyte tank 106 via the conduit 110 on the downstream side (discharge side). . Further, the negative electrode electrolyte is supplied from the negative electrode electrolyte tank 107 to the negative electrode 105 via the conduit 109 on the upstream side, and is supplied to the negative electrode electrolyte tank 107 from the negative electrode 105 via the conduit 111 on the downstream side (discharge side). Will be returned. The circulation of the positive electrode electrolyte and the circulation of the negative electrode electrolyte circulate and supply the positive electrode electrolyte to the positive electrode 104, and circulate and supply the negative electrode electrolyte to the negative electrode 105, and the active material ions in the electrolyte of each electrode Charge and discharge are performed along with the valence change reaction. In FIG. 1 and FIG. 2, vanadium ions shown in the positive electrode electrolyte tank 106 and the negative electrode electrolyte tank 107 show examples of ion species contained as an active material in the positive electrode electrolyte and in the negative electrode electrolyte. In FIG. 1, solid arrows indicate charging, and broken arrows indicate discharging.

[Cell stack]
The RF battery 1 is typically used in a form called a cell stack 2 in which a plurality of battery cells 100 are stacked. The cell stack 2 is, as shown in FIG. 3, a stacked body in which a cell frame 3, a positive electrode 104, a diaphragm 101, a negative electrode 105 and another cell frame 3 are repeatedly stacked, and a pair of end plates sandwiching the stacked body. 210 and 220, and a connecting member 230 such as a long bolt connecting between the end plates 210 and 220 and a fastening member such as a nut. When the end plates 210 and 220 are tightened by the fastening members, the stack is held in the stacked state by the tightening force in the stacking direction. The cell stack 2 uses a predetermined number of battery cells 100 as a sub stack 200, and is used in a form in which a plurality of sub stacks 200 are stacked.

[Cell frame]
As shown in FIG. 3, the cell frame 3 includes a bipolar plate 4 disposed between the positive electrode 104 and the negative electrode 105 and a frame 5 provided on the outer periphery of the bipolar plate 4. The bipolar plate 4 is made of a conductive member which allows current flow but does not flow electrolyte, and is disposed on one side to be in contact with the positive electrode 104 and on the other side to be in contact with the negative electrode 105. Be done. The frame 5 forms a region to be the battery cell 100 inside. For example, the thickness of the frame 5 is larger than the thickness of the bipolar plate 4, and by surrounding the outer periphery of the bipolar plate 4 with the frame 5, the surface (rear surface) of the bipolar plate 4 and the surface (rear surface) of the frame 5 Thus, a step is formed inside to form a space in which the positive electrode 104 (negative electrode 105) is disposed.

  The supply of the electrolytic solution of each electrode to the positive electrode 104 and the negative electrode 105 is performed by supplying liquid supply manifolds 51 and 52 formed on opposing pieces of the frame 5 in the cell frame 3 (the lower side in the drawing of FIG. 3). It is performed by the liquid supply guide grooves 51s and 52s. The discharge of the electrolyte solution of each electrode from the positive electrode 104 and the negative electrode 105 is performed by the drainage manifolds 53 and 54 formed on the other facing pieces (the upper side of the drawing of FIG. 3) of the frame 5 and drainage guide grooves. It is performed by 53s and 54s. The positive electrode electrolytic solution is supplied from the liquid supply manifold 51 to the positive electrode 104 through the liquid supply guide groove 51s formed on one surface side (surface side of the sheet) of the frame 5. Then, as shown by the arrows in the upper drawing of FIG. 3, the liquid flows from the lower side to the upper side of the positive electrode 104 to the upper side, and the drainage manifold 53 is formed through the drainage guide groove 53s formed on one surface side Discharged into The supply and discharge of the negative electrode electrolyte is the same as the positive electrode electrolyte except that it is performed on the other surface side (the back side of the sheet) of the frame 5. In order to suppress the leakage of the electrolytic solution from the battery cell 100, annular seal members 6 (FIGS. 2 and 3) such as O-rings and flat packings are disposed between the frames 5. A seal groove 57 (see FIG. 4) for arranging the annular seal member 6 is formed on the frame 5 along the circumferential direction.

  The basic configurations of the RF battery 1, the cell stack 2, and the cell frame 3 described above can appropriately use known configurations.

[Bipolar plate]
The bipolar plate 4A according to the first embodiment will be described with reference to FIG. The bipolar plate 4A is a member corresponding to the bipolar plate 4 described above. The upper drawing of FIG. 4 shows the flow of the electrolyte on the bipolar plate 4A during operation of the RF battery 1, and the lower drawing of FIG. 4 shows the bipolar plate 4A when the RF battery 1 is stopped (blackout) The storage condition of the electrolyte solution of In the upper view of FIG. 4, the frame 5 provided on the outer periphery of the bipolar plate 4A is also illustrated.

  The bipolar plate 4A is a rectangular flat plate as shown in FIG. The positive electrode 104 and the negative electrode 105 of the adjacent battery cells 100 are respectively disposed on the front and back surfaces of the bipolar plate 4A (see FIGS. 2 and 3). The bipolar plate 4A is disposed at a predetermined position of the RF battery 1 such that the opposing surface facing the positive electrode 104 and the opposing surface facing the negative electrode 105 are along the vertical direction. Hereinafter, the lower side in the vertical direction when the bipolar plate 4A is disposed at the predetermined position of the RF battery 1 is the lower side (lower side in the drawing of FIG. 4) of the bipolar plate 4A, and the upper side in the vertical direction is the upper side of the bipolar plate 4A (FIG. 4) The upper side of the paper).

  The bipolar plate 4 </ b> A is provided with a flow path 40 through which an electrolytic solution flows, on each of the facing surface facing the positive electrode 104 and the facing surface facing the negative electrode 105. The flow path 40 is provided in the battery cell 100 in order to adjust the flow of the electrolytic solution circulated to each of the positive electrode 104 and the negative electrode 105 by the pumps 112 and 113 (FIG. 1). The flow path 40 includes an inlet 40i for the electrolytic solution, an outlet 40o for the electrolytic solution, and a groove 41 for guiding the electrolytic solution introduced from the inlet 40i to the outlet 40o through a predetermined path.

  The inlet 40i is open at the lower edge of the bipolar plate 4A, and is connected to the liquid supply manifold 51 (52) (FIG. 3) via the liquid flow straightening unit 55 formed in the frame 5. . Although details will be described later, the bipolar plate 4A is provided with a plurality of introduction grooves 42 (introduction ports 40i) in parallel. The liquid feed straightening unit 55 diffuses the electrolytic solution from the liquid feed manifold 51 (52) in the parallel direction of the introduction groove portion 42 and supplies it to the introduction port 40i of each introduction groove portion 42.

  The discharge port 40o is opened at the upper edge of the bipolar plate 4A, and is connected to the drainage manifold 53 (54) (FIG. 3) via a drainage straightening unit 56 formed in the frame 5. Although details will be described later, the bipolar plate 4A is provided with a plurality of discharge grooves 43 (discharge ports 40o) in parallel. The liquid discharge straightening unit 56 collects the electrolytic solution discharged from the discharge port 40 o of each of the discharge grooves 43 and guides it to the liquid discharge manifold 53 (54).

  The groove portion 41 includes an introduction groove portion 42 connected to the introduction port 40i and a discharge groove portion 43 connected to the discharge port 40o. A plurality of introduction grooves 42 and discharge grooves 43 are provided. The introduction groove portion 42 and the discharge groove portion 43 are alternately arranged in parallel at predetermined intervals in a direction perpendicular to the vertical direction as well as along the vertical direction. That is, the introduction groove 42 and the discharge groove 43 are engaged with each other and disposed to face each other. A collar 45 is formed between the introduction groove 42 and the discharge groove 43 adjacent to each other. The bipolar plate 4A according to the first embodiment includes a plurality of units 44a in which the introduction groove portion 42 and the discharge groove portion 43 have a small cross-sectional area and are communicated by the high pressure loss communication portion, and adjacent units 44a exist independently of each other. It is one of the features. The form of communication between the introduction groove 42 and the discharge groove 43 will be described later.

  The positive electrode electrolyte is circulated through the groove 41 provided on one surface of the bipolar plate 4A on which the positive electrode 104 is disposed opposite, and the groove 41 provided on the other surface of the bipolar plate 4A on which the negative electrode 105 is disposed opposite. A negative electrode electrolyte is circulated. The flow of the electrolytic solution in each battery cell 100 can be adjusted by the shape, size, and the like of the groove 41. In addition, in FIG. 4, the size of the groove portion 41 is exaggerated and illustrated for easy understanding. Further, in FIG. 4, the ridge portion 45 is hatched in order to make it easy to understand. In addition, in FIG. 4, the introduction groove part 42 and the discharge groove part 43 have shown only one part, and have abbreviate | omitted the remaining part.

  The introduction groove portion 42 has a lower bent portion 420 which is bent toward the lower side of the bipolar plate 4A and an introduction groove portion 42 which is lower than the lower bend portion 420 in the longitudinal direction from the introduction port 40i to the tip of the introduction groove portion 42. And an introducing liquid reservoir 422 for storing an electrolytic solution on the tip side of the Similarly, the discharge groove 43 has an upper bent portion 430 bent toward the upper side of the bipolar plate 4A and a discharge groove 43 than the upper bent portion 430 in the longitudinal direction from the discharge port 40o toward the tip of the discharge groove 43. And an exhaust liquid reservoir 432 for storing the electrolytic solution on the tip side of the The introduction groove portion 42 and the discharge groove portion 43 communicate with each other by the communication portion formed by the introduction liquid reservoir portion 422 and the discharge liquid reservoir portion 432. In this example, the boundary between the introduction groove 42 and the discharge groove 43 is the central portion in the vertical direction of the communication portion. That is, the inlet 40 i side is the introduction groove part 42 than the central part, and the discharge port 40 o side is the discharge groove part 43 than the central part.

  The introduction groove portion 42 includes a longitudinal groove portion (introduction main groove portion 421) extending upward from the introduction port 40i, a lateral groove portion extending in the lateral direction of the bipolar plate 4A from the tip of the introduction main groove portion 421, and a lower bending portion 420 from the lateral groove portion. And a vertically extending groove (introductory liquid reservoir 422) extending downward. In the present example, the communication portion of the introduction groove portion 42 is configured by the lateral groove portion and the introduction liquid reservoir portion 422. Similarly, the discharge groove 43 has a vertical groove (discharge main groove 431) extending downward from the discharge port 40o, a horizontal groove extending in the lateral direction of the bipolar plate 4A from the tip of the discharge main groove 431, and an upper bend from the horizontal groove And a vertical groove (discharge liquid reservoir 432) extending upward at the portion 430. In the present example, the communication portion of the discharge groove portion 43 is configured by the horizontal groove portion and the liquid discharge reservoir portion 432.

  The introduced liquid storage section 422 and the discharged liquid storage section 432 have a role of a communication section that brings the inlet 40i and the outlet 40o into communication with each other. The introduced liquid reservoir 422 and the discharged liquid reservoir 432 are disposed so as to communicate the pair of the introduction groove 42 and the discharge groove 43 adjacent to each other. A unit 44a of a pair of the introduction groove portion 42 and the discharge groove portion 43 in which the introduction port 40i and the discharge port 40o communicate with each other is formed by the number of the introduction groove portions 42 (discharge groove portions 43). The adjacent units 44a exist independently without communicating with each other.

  The introduction liquid reservoir 422 and the discharge liquid reservoir 432 have a cross-sectional area smaller than the cross-sectional area of the introduction groove 42 other than the introduction liquid reservoir 422 and the cross-sectional area of the discharge groove 43 other than the drainage liquid reservoir 432. The cross-sectional area of the introduction groove portion 42 other than the introduction liquid reservoir portion 422 is the cross-sectional area of the introduction groove portion 42 (introduction main groove portion 421) from the introduction port 40i to the lower bent portion 420. In this example, the introduction main groove 421 has a uniform width and depth along the longitudinal direction. Similarly, the cross-sectional area of the discharge groove 43 other than the liquid storage portion 432 is the cross-sectional area of the discharge groove 43 (discharge main groove 431) from the discharge port 40o to the upper bent portion 430. In this example, the main discharge groove 431 has a uniform width and depth along the longitudinal direction. The introduction liquid reservoir 422 and the discharge liquid reservoir 432 have a cross-sectional area smaller than the cross-sectional area of each of the introduction main groove 421 and the discharge main groove 431, so that high pressure is applied to the introduction main groove 421 and the discharge main groove 431. It will be a loss. The cross sectional area of the introduced liquid reservoir 422 and the discharged liquid reservoir 432 is, for example, 1% or more and 50% or less, and further 5% or more and 30% or less of the cross sectional area of the introduced main groove 421 and the discharged main groove 431. Be

  For example, the introductory liquid reservoir 422 and the discharge liquid reservoir 432 have the introductory main groove 421 and the discharge liquid so that the inflow liquid reservoir 422 and the discharge liquid reservoir 432 have high pressure loss with respect to the introduction main groove 421 and the discharge main groove 431. The width may be smaller than the width of the main groove portion 431. The width of the introductory main groove 421 and the discharge main groove 431 is, for example, 0.1 mm or more and 10 mm or less, and further 0.5 mm or more and 2.5 mm or less so that the cross-sectional area becomes sufficiently large. The widths of the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are, for example, 1% or more and 50% or less, and further 5% or more and 30% or less of the widths of the introduction main groove 421 and the discharge main groove 431. In this example, the width of the introduction main groove 421 and the width of the discharge main groove 431 are the same, but may be different. In that case, the widths of the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are higher than that of the main grooves 421, 431 according to the width of the main grooves 421, 431 connected to the respective liquid reservoirs 422, 432. It may be selected as appropriate. Further, the distance between adjacent groove portions 41 (between the introduction main groove portion 421 and the discharge main groove portion 431), that is, the width of the ridge 45 is 100% or more and 700% or less of the width of the introduction main groove portion 421 and the discharge main groove portion 431. And 200% or more and 500% or less. The introduced liquid reservoir 422 and the discharged liquid reservoir 432 are formed within the width of the ridge 45.

  For example, the introductory liquid reservoir 422 and the discharge liquid reservoir 432 have the introductory main groove 421 and the discharge liquid so that the inflow liquid reservoir 422 and the discharge liquid reservoir 432 have high pressure loss with respect to the introduction main groove 421 and the discharge main groove 431. It has a depth shallower than the depth of the main groove 431. The depths of the introduction main groove 421 and the discharge main groove 431 may be 5% or more and 45% or less of the thickness of the bipolar plate 4A. When the groove 41 is provided on the front and back surfaces of the bipolar plate 4A, the depth of the groove 41 may be 20% of the thickness of the bipolar plate 4A because the mechanical strength may be reduced if the depth of the groove 41 is too deep. More than 40% is more preferable. The depths of the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are, for example, 1% or more and 50% or less, and further 5% or more and 30% or less of the depths of the introduction main groove 421 and the discharge main groove 431. Be In this example, the depth of the introduction main groove 421 and the depth of the discharge main groove 431 are the same, but may be different. In that case, the depths of the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are higher than those of the main grooves 421, 431 according to the depths of the main grooves 421, 431 connected to the respective liquid reservoirs 422, 432. It may be selected as appropriate.

[During operation of RF battery]
In the bipolar plate 4A, when the RF battery 1 is in operation, as shown in the upper drawing of FIG. 4, the electrolyte introduced from the liquid supply manifold 51 (52) to the liquid supply straightening unit 55 is distributed to each inlet 40i. And flows through the introduction main groove 421 of the introduction groove 42 from each introduction port 40i and spreads over the entire surface of the bipolar plate 4A. The electrolyte flowing into the introduction main groove 421 penetrates the electrode disposed on the surface of the bipolar plate 4A, and flows to the discharge main groove 431 of the discharge groove 43 adjacent to the introduction groove 42 across the surface of the bipolar plate 4A. The electrolytic solution flowing to the main drain groove portion 431 is discharged and collected from the discharge port 40o to the drainage rectification portion 56, and is discharged from the drainage manifold 53 (54) to the outside of the battery cell 100. That is, the flow of the electrolyte on the bipolar plate 4A is the flow along the introduction main groove 421 and the discharge main groove 431 (the direction of the solid line arrow shown in the upper view of FIG. 4), the introduction main groove 421 and the discharge main groove A flow (in the direction of the broken arrow shown in the upper view of FIG. 4) is formed so as to extend in the lateral direction (left and right direction in FIG. 4) via the ridge portion 45 between 431 and 431.

  In the bipolar plate 4A, a pair of the introduction groove portion 42 and the discharge groove portion 43 which are adjacent to each other communicate with each other at a communication portion (the introduction liquid reservoir 422 and the discharge liquid reservoir 432). However, since the introduced liquid reservoir 422 and the discharged liquid reservoir 432 have a smaller cross-sectional area than the introduced main groove 421 and the discharged main groove 431 and have high pressure loss, the introduced liquid reservoir 422 and The electrolyte is more likely to flow through the introductory main groove 421 and the discharge main groove 431 which have a lower pressure loss than the discharge liquid reservoir 432. Therefore, the amount of electrolytic solution flowing to the introduced liquid reservoir 422 and the discharged liquid reservoir 432 can be sufficiently smaller than the amount of electrolytic solution flowing to the introduction main groove 421 and the discharge main groove 431. Even if communication is made from the inlet 40i to the outlet 40o, if the amount of electrolytic solution flowing to the introduced liquid reservoir 422 and the discharged liquid reservoir 432 is small, the electrolysis is discharged unreacted from the battery cell 100 (FIG. 1). The amount of liquid can be reduced, and by forming the flow of the electrolytic solution across the ridge portion 45, the battery reaction can be sufficiently performed, and the battery efficiency is hardly disturbed.

[When the RF battery is shut off]
On the other hand, in the case of the bipolar plate 4A, when the pumps 112 and 113 (FIGS. 1 and 2) are stopped due to a power failure or the like, the electrolyte in the discharge groove 43 is left as it is in the discharge groove 43 as shown in the lower diagram of FIG. The electrolytic solution in the introduction groove 42 is partially stored in the introduction liquid reservoir 422 (slant hatching to the right in the lower view of FIG. 4) The part is discharged from the inlet 40i to the outside of the battery cell 100 through the liquid flow straightening unit 55 and the liquid supply manifold 51 (52). Since the electrolyte can be stored in the introduction liquid reservoir 422 in the discharge groove 43 and in the introduction groove 42, even if the pumps 112 and 113 are stopped due to a power failure or the like, the stored electrolytic solution of the RF battery 1 You can start it. Although the amount of electrolytic solution stored in one bipolar plate 4A is relatively small, a considerable amount of electrolytic solution can be stored in the entire cell stack 2 in which a large number of cell frames 3 are stacked. It is sufficient to obtain enough power to start up.

  If the pumps 112 and 113 can be started by starting the RF battery 1, thereafter, the pumps 112 and 113 are continuously operated using the power of the RF battery 1 and the power is supplied to the system from the RF battery 1. can do. Further, in the bipolar plate 4A, even when the RF battery 1 is intentionally stopped, the stored electrolytic solution can start the RF battery 1 early.

  In the bipolar plate 4A, since a plurality of units 44a of the introduction groove portion 42 and the discharge groove portion 43 in which the introduction liquid reservoir 422 and the discharge liquid reservoir 432 communicate with each other by high pressure loss exist, the introduction is performed. The state of charge of the electrolyte can be made uniform over the entire bipolar plate 4A, as compared to the case where there is only one port 40i and only one outlet 40o and all the units 44a are in communication.

Embodiment 2
The bipolar plate 4B according to the second embodiment will be described with reference to FIG. The upper view of FIG. 5 shows the flow of the electrolyte on the bipolar plate 4B during operation of the RF battery 1, and the lower view of FIG. 5 shows the electrolysis on the bipolar plate 4B during stoppage (power failure) of the RF battery 1. Indicates the liquid storage condition.

[Bipolar plate]
The bipolar plate 4B according to the second embodiment is characterized in that the introduction groove 42 and the discharge groove 43 are separated from each other, and the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are engaged with each other and disposed to face each other. To be

  The introduction groove 42 includes a longitudinal groove (introduction main groove 421) extending upward from the introduction port 40i, a lateral groove extending in the lateral direction of the bipolar plate 4B from the tip of the introduction main groove 421, and a lower bending portion 420 from the lateral groove. And a vertically extending groove (introductory liquid reservoir 422) extending downward. In the present example, the introduction groove 42 has a uniform width and depth along its longitudinal direction. That is, in the introduction groove portion 42, the introduction main groove portion 421 and the introduction liquid reservoir portion 422 have substantially the same pressure loss. The width and the depth of the introductory liquid reservoir 422 can be appropriately selected so that the pressure loss can flow through the electrolyte during operation of the RF battery 1. By doing so, the introduced liquid reservoir 422 can function as a flow path of the electrolyte during operation of the RF battery 1. Moreover, the cross-sectional area of the introductory liquid storage part 422 can be enlarged compared with Embodiment 1, and the amount of electrolyte solution which can be stored can be increased. The cross sectional area of the inflow reservoir 422 may be smaller than the cross sectional area of the introductory main groove 421.

  The discharge groove 43 includes a vertical groove (discharge main groove 431) extending downward from the discharge port 40o, a horizontal groove extending in the lateral direction of the bipolar plate 4A from the tip of the discharge main groove 431, and an upper bent portion 430 from the horizontal groove. And a longitudinally extending groove (discharge liquid reservoir 432) extending upward. In the present example, the discharge groove 43 has a uniform width and depth along its longitudinal direction. That is, in the discharge groove portion 43, the discharge main groove portion 431 and the discharge liquid reservoir portion 432 have substantially the same pressure loss. The width and depth of the discharge liquid reservoir 432 can be appropriately selected so that the pressure loss can flow through the electrolyte during operation of the RF battery 1. By doing so, the discharge liquid reservoir 432 can function as a flow path of the electrolyte during operation of the RF battery 1. Moreover, the cross-sectional area of the discharge liquid storage part 432 can be enlarged compared with Embodiment 1, and the amount of electrolyte solution which can be stored can be increased. The cross-sectional area of the drain liquid reservoir 432 may be smaller than the cross-sectional area of the main drain groove 431.

  The introduction groove portion 42 and the discharge groove portion 43 have closed end portions separated from each other. Specifically, the introduction groove portion 42 has a closed end portion at the tip end (lower end portion) when the introduction port 40i is at the start end, and the discharge groove portion 43 has a tip end portion (upper end when the discharge port 40o is at the start end Section) with a closed end. By providing each of the introduction groove 42 and the discharge groove 43 with a closed end, the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are engaged with each other without being in communication with each other. The introductory liquid reservoir 422 is folded back at the lower bending portion 420 so as to be interposed between the discharge main groove 431 and the drainage liquid reservoir 432 with respect to the adjacent discharge groove 43, and is disposed extending downward. ing. Similarly, the drainage liquid reservoir 432 is folded back at the upper bending portion 430 and extended upward so as to be interposed between the introduction main groove 421 and the introduction liquid reservoir 422 with respect to the adjacent introduction groove 42. It is arranged. As many units 44b of the introduction groove part 42 and the discharge groove part 43 as a pair of the introduction groove part 42 and the discharge groove part 43 in which the introduction liquid storage part 422 and the discharge liquid storage part 432 engage and are opposed to each other are formed. . The units 44b adjacent to each other exist independently without communicating with each other.

[During operation of RF battery]
During the operation of the RF battery 1, as shown in the upper drawing of FIG. 5, the flow of the electrolyte on the bipolar plate 4B is a flow along the introduction groove 42 and the discharge groove 43 (solid arrow shown in the upper drawing of FIG. And the flow (in the direction of the broken arrow shown in the upper view of FIG. 5) such that it crosses in the lateral direction (left and right direction in FIG. 5) via the ridge 45 between the introduction groove 42 and the discharge groove 43 Form The flow along the introduction groove 42 forms a flow from the introduction main groove 421 to the introduction liquid reservoir 422, and the flow along the discharge groove 43 flows from the discharge liquid reservoir 432 to the discharge main groove 431. Form

[When the RF battery is shut off]
On the other hand, in the bipolar plate 4B, when the pumps 112 and 113 (FIGS. 1 and 2) stop due to a power failure or the like, as shown in the lower diagram of FIG. (In the lower part of the lower diagram in FIG. 5 diagonal hatching), a portion of the electrolyte in the introduction groove 42 is stored in the introductory solution reservoir 422 (the lower hatching in the lower diagram of FIG. 5 diagonal hatching) 4 are discharged to the outside of the battery cell 100 from the inlet 40i through the liquid flow straightening unit 55 and the liquid supply manifold 51 (52) of FIG. The electrolyte can be stored in the introduction groove in the discharge groove 43 and in the introduction groove 42, so that even if the pumps 112 and 113 stop due to a power failure or the like as in the first embodiment, the solution is stored. The electrolyte solution can start the RF battery 1. In the bipolar plate 4B, the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are not in communication with each other and are engaged with each other so as to face each other, so that the battery reaction can be efficiently performed by the stored electrolytic solution. Easy to do early.

Embodiment 3
The bipolar plate 4C according to the third embodiment will be described with reference to FIG. The upper drawing of FIG. 6 shows the flow of the electrolyte on the bipolar plate 4C during operation of the RF battery 1, and the lower drawing of FIG. 6 shows the electrolysis on the bipolar plate 4C when the RF battery 1 is stopped (blackout) Indicates the liquid storage condition.

[Bipolar plate]
The bipolar plate 4C according to the third embodiment includes two introductory liquid reservoirs 422 in one introduction groove 42 and two drain liquid reservoirs 432 in one discharge groove 43, and the introductory liquid reservoir 422 and the drainage One feature is that the liquid reservoirs 432 and the liquid reservoirs 432 are not in communication and are engaged with each other and disposed to face each other.

  The introduction groove portion 42 includes a longitudinal groove portion (introduction main groove portion 421) extending upward from the introduction port 40i, two lateral groove portions extending respectively in the left-right direction of the bipolar plate 4C from the tip of the introduction main groove portion 421, and a lower portion from each lateral groove portion. And a longitudinal groove (introductory liquid reservoir 422) extending downward at the side bend 420. In this example, the width of the inflow liquid reservoir 422 is narrower than the widths of the introductory main groove 421 and the lateral groove.

  The discharge groove portion 43 includes a vertical groove portion (discharge main groove portion 431) extending downward from the discharge port 40o, two horizontal groove portions extending in the lateral direction of the bipolar plate 4C from the tip of the discharge main groove portion 431, and an upper side from each horizontal groove portion. And a vertical groove (discharge liquid reservoir 432) extending at the bent portion 430 and extending upward. In this example, the width of the drain liquid reservoir 432 is narrower than the widths of the main drain groove 431 and the lateral groove.

  The introduction groove portion 42 and the discharge groove portion 43 have closed end portions separated from each other. Specifically, the introduction groove portion 42 is provided with a closed end at each of the tip end portions (lower end portion) when the introduction port 40i is at the start end, and the discharge groove portion 43 is a tip end portion when the discharge port 40o is at the start end. Each of the (upper end) is provided with a closed end. By providing each of the introduction groove 42 and the discharge groove 43 with a closed end, the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are engaged with each other without being in communication with each other. The introductory liquid reservoir 422 is folded back at the lower bending portion 420 so as to be interposed between the discharge main groove 431 and the drainage liquid reservoir 432 with respect to the adjacent discharge groove 43, and is disposed extending downward. ing. Similarly, the drainage liquid reservoir 432 is folded back at the upper bending portion 430 and extended upward so as to be interposed between the introduction main groove 421 and the introduction liquid reservoir 422 with respect to the adjacent introduction groove 42. It is arranged.

[During operation of RF battery]
During operation of the RF battery 1, as shown in the upper drawing of FIG. 6, the flow of the electrolyte on the bipolar plate 4C is a flow along the introduction groove 42 and the discharge groove 43 (solid arrow shown in the upper drawing of FIG. And the flow (in the direction of the broken line arrow shown in the upper view of FIG. 6) across the lateral direction (left and right direction in FIG. 6) through the ridge 45 between the introduction groove 42 and the discharge groove 43 Form The flow along the introduction groove 42 forms a flow from the introduction main groove 421 to the introduction liquid reservoir 422, and the flow along the discharge groove 43 flows from the discharge liquid reservoir 432 to the discharge main groove 431. Form

[When the RF battery is shut off]
On the other hand, in the bipolar plate 4C, when the pumps 112 and 113 (FIGS. 1 and 2) stop due to a power failure or the like, as shown in the lower diagram of FIG. (FIG. 6 lower slanting hatching in the lower view of FIG. 6), a portion of the electrolytic solution in the introduction groove 42 is stored in the introductory liquid reservoir 422 (lower slanting downward hatching in FIG. 6) 4 are discharged to the outside of the battery cell 100 from the inlet 40i through the liquid flow straightening unit 55 and the liquid supply manifold 51 (52) of FIG. The electrolyte can be stored in the introduction groove in the discharge groove 43 and in the introduction groove 42, so that even if the pumps 112 and 113 stop due to a power failure or the like as in the first embodiment, the solution is stored. The electrolyte solution can start the RF battery 1. The bipolar plate 4C is provided with two introductory liquid reservoirs 422 and two drainage liquid reservoirs 432 in the introduction groove 42 and the discharge groove 43, respectively, and the respective introduction liquid reservoirs 422 and the drainage liquid reservoir 432 do not communicate with each other. Since they are engaged with each other and arranged to face each other, the battery reaction can be efficiently performed by the stored electrolytic solution, and the RF battery 1 can be easily activated at an early stage.

<< Embodiment 4 >>
The bipolar plate 4D according to the fourth embodiment will be described with reference to FIG. The upper view of FIG. 7 shows the flow of the electrolyte on the bipolar plate 4D during operation of the RF battery 1, and the lower view of FIG. 7 shows the electrolysis on the bipolar plate 4D during stop of the RF battery 1 (power failure). Indicates the liquid storage condition.

[Bipolar plate]
The bipolar plate 4D according to the fourth embodiment includes a plurality of introduced liquid reservoirs 422 along the longitudinal direction of the introduction groove 42, and includes a plurality of liquid reservoirs 432 along the longitudinal direction of the discharge groove 43. One feature is that the fluid reservoir 422 and the fluid reservoir 432 are not in communication and are engaged with each other and disposed opposite to each other.

  The introduction groove portion 42 is extended in a direction intersecting the vertical direction of the bipolar plate 4D halfway through the introduction trunk groove portion (introduction main groove portion) 421 extending upward from the introduction port 40i and the introduction trunk groove portion 421. And an introduction branch groove portion 423. In this example, the width of the introduction branch groove 423 is smaller than the width of the introduction trunk groove 421. The introduction branch groove portion 423 is a lower bent portion 420 that bends downward in the bipolar plate 4D halfway in the longitudinal direction toward the tip, and an introduced liquid reservoir portion that stores the electrolyte on the tip side of the lower bend portion 420. And 422.

  The discharge groove portion 43 is extended in a direction intersecting the vertical direction of the bipolar plate 4D in the middle of the discharge trunk groove portion (discharge main groove portion) 431 extending downward from the discharge port 40o and the discharge trunk groove portion 431 in the longitudinal direction. And a discharge branch groove portion 433. In this example, the width of the discharge branch groove portion 433 is smaller than the width of the discharge trunk groove portion 431. The discharge branch groove portion 433 has an upper bent portion 430 which is bent toward the upper side of the bipolar plate 4D halfway in the longitudinal direction toward the tip, and a discharge liquid reservoir portion 432 which stores the electrolytic solution on the tip side of the upper bent portion 430. Equipped with

  The introduction groove portion 42 and the discharge groove portion 43 have closed end portions which are separated from each other. Specifically, the introduction groove 42 has a closed end at the tip of each introduction branch groove 423, and the discharge groove 43 has a closed end at the tip of each discharge branch 433. By providing each of the introduction groove 42 and the discharge groove 43 with a closed end, the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are engaged with each other without being in communication with each other. The introductory liquid reservoir 422 is folded back at the lower bending portion 420 and extended downward so as to be interposed between the discharge trunk groove 431 and the drainage liquid reservoir 432 with respect to the adjacent discharge groove 43. ing. Similarly, the drainage liquid reservoir 432 is folded back at the upper bending portion 430 and extended upward so as to be interposed between the introduction trunk groove 421 and the introduction liquid reservoir 422 with respect to the adjacent introduction groove 42. It is arranged. The introduction branch groove portion 423 is extended on both sides of the introduction trunk groove portion 421, and the discharge branch groove portion 433 is extended on both sides of the discharge trunk groove portion 431. Therefore, the introduced liquid reservoir 422 and the discharged liquid reservoir 432 are engaged with each other on both sides of the trunk grooves 421 and 431 so as to be opposed to each other.

[During operation of RF battery]
During the operation of the RF battery 1, as shown in the upper drawing of FIG. 7, the flow of the electrolyte on the bipolar plate 4D is a flow along the introduction groove 42 and the discharge groove 43 (solid arrow shown in the upper drawing of FIG. And the flow (in the direction of the broken arrow shown in the upper view of FIG. 7) such that it crosses in the lateral direction (left and right direction in FIG. 7) via the ridge 45 between the introduction groove 42 and the discharge groove 43 Form The flow along the introduction groove 42 forms a flow from the introduction trunk groove 421 to the introduction liquid reservoir 422, and the flow along the discharge groove 43 flows from the discharge liquid reservoir 432 to the discharge trunk groove 431. Form

[When the RF battery is shut off]
On the other hand, in the bipolar plate 4D, when the pumps 112 and 113 (FIGS. 1 and 2) stop due to a power failure or the like, as shown in the lower diagram of FIG. 7 is partially stored in the introductory solution reservoir 422 (the downward hatching in the lower part of FIG. 7), and the others are stored in the 4 are discharged to the outside of the battery cell 100 from the inlet 40i through the liquid flow straightening unit 55 and the liquid supply manifold 51 (52) of FIG. The electrolyte can be stored in the introduction groove in the discharge groove 43 and in the introduction groove 42, so that even if the pumps 112 and 113 stop due to a power failure or the like as in the first embodiment, the solution is stored. The electrolyte solution can start the RF battery 1. The bipolar plate 4D includes a plurality of introduced liquid reservoirs 422 and a discharged liquid reservoir 432 along the longitudinal direction of the introduction groove 42 and the discharged groove 43, and each introduced liquid reservoir 422 and the discharged liquid reservoir 432 are not Since they are engaged with each other in communication and opposed to each other, battery reactions can be efficiently performed by the stored electrolytic solution, and the RF battery 1 can be easily activated at an early stage.

Embodiment 5
The bipolar plate 4E according to the fifth embodiment will be described with reference to FIG. The upper drawing of FIG. 8 shows the flow of the electrolyte on the bipolar plate 4E during operation of the RF battery 1, and the lower drawing of FIG. 8 shows the electrolysis on the bipolar plate 4E when the RF battery 1 is stopped (blackout) Indicates the liquid storage condition.

[Bipolar plate]
The bipolar plate 4E according to the fifth embodiment is characterized in that each of the introduction groove portion 42 and the discharge groove portion 43 is formed in a spiral shape which is separated from each other.

  The introduction groove portion 42 includes a horizontal groove portion and a vertical groove portion that form a spiral from the introduction port 40i toward the center of the bipolar plate 4E. In the present embodiment, the lateral groove portion of the introduction groove portion 42 is connected to the introduction port 40i. Further, in the present embodiment, the introduction groove 42 constitutes two layers of spirals, and two horizontal grooves and two longitudinal grooves which constitute the outer side of the spiral and one horizontal groove which constitutes the inner side of the spiral. Provided with two flutes. The introduction groove portion 42 is provided with a lower bending portion 420 which is bent toward the lower side of the bipolar plate 4E in the middle of its longitudinal direction in forming a spiral. An introduction liquid reservoir 422 for storing an electrolytic solution is provided on the tip side of the introduction groove 42 with respect to the lower bent portion 420.

  The discharge groove portion 43 includes a horizontal groove portion and a vertical groove portion that form a spiral from the discharge port 40o toward the center of the bipolar plate 4E. In the present embodiment, the lateral groove portion of the discharge groove portion 43 is connected to the discharge port 40o. Further, in this example, the discharge groove portion 43 constitutes a spiral of two layers, and two horizontal groove portions and two longitudinal groove portions constituting the outer side of the spiral and one horizontal groove portion constituting the inner side of the spiral. Provided with two flutes. The discharge groove part 43 is provided with the upper side bending part 430 bent toward the upper side of the bipolar | dipolar board 4E in the middle of the longitudinal direction, in comprising a spiral. A discharge liquid reservoir 432 for storing the electrolytic solution is provided on the tip side of the discharge groove 43 with respect to the upper bent portion 430.

  The inlet 40i and the outlet 40o are located approximately diagonally. Accordingly, by arranging the introduction groove 42 and the discharge groove 43 concentrically, it is possible to form a spiral so as to be engaged with each other and arranged to face each other. When viewed from the center of the spiral to the outer peripheral side, the introduction groove portion 42 and the discharge groove portion 43 are alternately juxtaposed, and a closed end portion is provided at the center side end of the spiral of each groove portion 42, 43.

[During operation of RF battery]
During the operation of the RF battery 1, as shown in the upper drawing of FIG. 8, the flow of the electrolyte on the bipolar plate 4E is a spiral flow along the introduction groove 42 and the discharge groove 43 (in the upper drawing of FIG. A flow (vertical direction in FIG. 8) indicated by the solid line arrow shown) and the vertical direction (vertical direction in FIG. 8) through the ridge 45 between the introduction groove 42 and the discharge groove 43 Direction).

[When the RF battery is shut off]
On the other hand, in the case of the bipolar plate 4E, when the pumps 112 and 113 (FIGS. 1 and 2) are stopped due to a power failure or the like, the electrolyte in the discharge groove 43 is left as it is in the discharge groove 43 as shown in the lower diagram of FIG. (In the lower part of the lower diagram in FIG. 8 diagonally hatched), a portion of the electrolytic solution in the introduction groove 42 is stored in the introductory solution reservoir 422 (the diagonally lower right hatching in the lower diagram of FIG. 8) 4 are discharged to the outside of the battery cell 100 from the inlet 40i through the liquid flow straightening unit 55 and the liquid supply manifold 51 (52) of FIG. The electrolyte can be stored in the introduction groove in the discharge groove 43 and in the introduction groove 42, so that even if the pumps 112 and 113 stop due to a power failure or the like as in the first embodiment, the solution is stored. The electrolyte solution can start the RF battery 1. The bipolar plate 4E easily increases the area where the introduction groove portion 42 and the discharge groove portion 43 are engaged with each other to be opposed to each other, and the introduction liquid reservoir 422 can be arranged at the central portion of the bipolar plate 4E. Thus, the battery reaction can be efficiently performed, and the RF battery 1 can be easily activated at an early stage.

Embodiment 6
The bipolar plate 4F according to the sixth embodiment will be described with reference to FIG. Similar to the bipolar plate 4E according to Embodiment 5, the bipolar plate 4F according to Embodiment 6 is characterized in that each of the introduction groove portion 42 and the discharge groove portion 43 is configured in a spiral shape divided from each other. . The bipolar plate 4F according to the sixth embodiment is different from the bipolar plate 4E according to the fifth embodiment in that the inlet 40i and the outlet 40o are respectively connected to the vertical groove, and the other points are the same.

  In the bipolar plate 4F according to the sixth embodiment, the flow of the electrolyte on the bipolar plate 4F is along the introduction groove 42 and the discharge groove 43 during operation of the RF battery 1 similarly to the bipolar plate 4E according to the fifth embodiment. Flow in the lateral direction (left-right direction in FIG. 9) via the ridge portion 45 between the introduction groove portion 42 and the discharge groove portion 43 (in the direction of the solid line arrow shown in the left view of FIG. Flow (in the direction of the dashed arrow shown in the left view of FIG. 9). Then, when the RF battery 1 is stopped, the electrolytic solution in the discharge groove 43 is stored as it is in the discharge groove 43 including the discharge liquid storage 432 (slant hatching in the lower left of the right in FIG. 9). Part of the electrolyte inside is stored in the introductory solution reservoir 422 (diagonal hatching downward to the right in the right figure of FIG. 9), and the other part is from the inlet 40i to the liquid flow straightening part 55 of FIG. The battery is discharged to the outside of the battery cell 100 through 51 (52).

  The present invention is not limited to these exemplifications, is shown by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims. For example, the specification (the size, shape, number, etc. of the introduction groove and the discharge groove) of the groove of the bipolar plate can be changed. In addition, the liquid supply straightening unit and the drain straightening unit may be grooves formed in the bipolar plate.

1 Redox flow battery (RF battery)
Reference Signs List 2 cell stack 3 cell frame 4, 4A, 4B, 4C, 4D, 4F bipolar plate 40 flow path 40i inlet 40o outlet 41 groove 42 introduction groove 420 lower bent portion 421 introduction main groove (introduction groove)
422 Introduction liquid reservoir 423 Introduction branch groove 43 Discharge groove 430 Upper bent portion 431 Discharge main groove (discharge trunk groove)
432 drainage liquid reservoir 433 drainage branch groove 44a, 44b unit 45 ridge 5 frame 51, 52 supply manifold 53, 54 drainage manifold 51s, 52s supply guide groove 53s, 54s drainage guide groove 55 supply straightener 56 drainage drainage part 57 seal groove 6 seal member 100 battery cell 101 diaphragm 102 positive electrode cell 103 negative electrode cell 104 positive electrode 105 negative electrode 100P positive electrode circulation mechanism 100N negative electrode circulation mechanism 106 positive electrode electrolyte tank 107 negative electrode electrolyte tank 108, 109, 110, 111 Conduit 112, 113 Pump 200 Sub-stack 210, 220 End plate 230 Connection member

Claims (12)

A bipolar plate, which is disposed between a positive electrode and a negative electrode of a redox flow battery, and has a flow path through which an electrolytic solution flows on the opposite surface facing at least one of the positive electrode and the negative electrode.
When the lower side in the vertical direction when the bipolar plate is disposed at a predetermined position of the redox flow battery so that the facing surface is along the vertical direction is the lower side of the bipolar plate and the upper side in the vertical direction is the upper side of the bipolar plate ,
The flow path is
An electrolyte inlet on the lower side of the bipolar plate,
An electrolyte outlet on the upper side of the bipolar plate,
An introduction groove connected to the introduction port;
And a discharge groove connected to the discharge port;
The introduction groove portion and the discharge groove portion are
A communication portion having a locally small cross-sectional area and communicating the inlet and the outlet,
Or a closed end that separates the introduction groove and the discharge groove from each other,
The introduction groove portion is
A lower bending portion that bends toward the lower side of the bipolar plate midway in the longitudinal direction from the introduction port toward the tip of the introduction groove portion;
A bipolar plate comprising: an introduction liquid reservoir for storing an electrolytic solution on the front end side of the introduction groove than the lower bent portion.   The bipolar plate according to claim 1, wherein each of the introduction groove portion and the discharge groove portion includes a comb-tooth region which is disposed in mesh with and opposed to each other. The discharge groove portion is
An upper bent portion which is bent toward the upper side of the bipolar plate midway in the longitudinal direction from the discharge port toward the tip of the discharge groove;
A discharge liquid reservoir for storing an electrolytic solution on the front end side of the discharge groove with respect to the upper bent portion;
The bipolar plate according to claim 2, wherein the introduction liquid reservoir and the discharge liquid reservoir are provided in the communication unit.   The bipolar plate according to claim 3, wherein the introduction liquid reservoir and the discharge liquid reservoir have a locally narrow width.   The bipolar plate according to claim 3 or 4, wherein the inflow reservoir and the drainage reservoir are locally shallow. A plurality of units in which the inlet and the outlet communicate with each other at the communication portion;
The bipolar plate according to any one of claims 3 to 5, wherein the adjacent units are present independently of each other. The discharge groove portion is
An upper bent portion which is bent toward the upper side of the bipolar plate midway in the longitudinal direction from the discharge port toward the tip of the discharge groove;
A discharge liquid reservoir for storing an electrolytic solution on the front end side of the discharge groove with respect to the upper bent portion;
The introduction groove portion and the discharge groove portion are separated from each other,
The bipolar plate according to claim 2, wherein the introductory liquid reservoir and the discharge liquid reservoir are engaged with each other and disposed to face each other. The introduction groove portion is
An introduction stem groove along the vertical direction of the bipolar plate;
A plurality of introduction branch grooves extending in a direction intersecting the vertical direction of the bipolar plate midway in the longitudinal direction of the introduction trunk groove;
And an inlet fluid reservoir at the end of the inlet branch groove,
The discharge groove portion is
A discharge trunk groove along the vertical direction of the bipolar plate;
A plurality of discharge branch grooves extending in a direction intersecting the vertical direction of the bipolar plate midway in the longitudinal direction of the discharge trunk groove;
The bipolar plate according to claim 7, further comprising: the drainage reservoir at a tip end of the drainage branch groove.   The bipolar plate according to claim 2, wherein the introduction groove portion and the discharge groove portion are configured in a spiral shape separated from each other.   A cell frame comprising the bipolar plate according to any one of claims 1 to 9 and a frame provided on the outer periphery of the bipolar plate.   A cell stack comprising the cell frame according to claim 10.   A redox flow battery comprising the cell stack according to claim 11.

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