KR102586856B1 - Bipolar Plate for Redox Flow Battery, stack and Redox Flow Battery using The Same - Google Patents

Abstract

The present invention relates to a plurality of flow channels formed in a flow path on one side of an electrode in a stack, each having a predetermined pattern with one side open, forming a path through which electrolyte flows, and a distribution layer spaced apart from the flow path layer by a predetermined distance. Two distribution channels formed in a distribution layer and two distribution channels that are formed in a pattern according to the arrangement positions of the multiple flow channels and externally supply or discharge the electrolyte flowing into or discharged from the plurality of flow channels. It includes a plurality of interlayer flow paths that connect the input and output ends of the plurality of flow channels formed in each furnace and flow layer, respectively, and can improve output, energy density, and energy efficiency by improving electrolyte distribution and pressure uniformity within the electrode. Provided are bipolar plates and stacks for redox flow batteries, and redox flow batteries using the same.

Description

Bipolar plate for redox flow battery, stack, and redox flow battery using the same {Bipolar Plate for Redox Flow Battery, stack and Redox Flow Battery using The Same}

The present invention relates to a bipolar plate and stack for a redox flow battery, and a redox flow battery using the same. It relates to a bipolar plate and stack for a redox flow battery having a three-dimensional flow path structure, and a redox flow battery using the same.

As demand for renewable energy increases, interest in energy storage systems (ESS) that can efficiently store and manage it is also increasing. Existing ESS mainly used lithium-ion batteries, but due to issues such as human hazard and fire risk, research has recently been actively conducted to replace them with flow batteries such as redox flow batteries (RFB) or fuel cells. It is becoming.

Unlike lithium-ion batteries, flow batteries such as redox flow batteries or fuel cells have a structure divided into a tank that functions as an electrolyte reservoir and a stack containing electrodes, and the electrolyte (or electrolyte) of the fluid or gas stored in the tank. As the active material (referred to as an active material) circulates through at least one battery cell constituting the stack, power is generated by causing a chemical reaction at the interface of the porous electrode inside the battery cell.

This type of redox flow battery has the advantage of being easy to expand as unit cells can be stacked to form a stack to increase output or the capacity can be increased by enlarging the tank size, but it has the problem of low energy density and energy efficiency. there is. And since high-output, large-capacity redox flow batteries must be used in the industry, not only is the number of unit cells stacked in a stack increasing, but the area of the unit cells themselves is also greatly increasing. However, when the distant enemy of the unit cell itself increases, there is a problem that energy efficiency is further reduced due to uneven concentration of the electrolyte supplied to the porous electrode in each region, pressure difference, and leakage current. Therefore, a method to improve energy efficiency in large-area cells is required.

Korea Registered Patent No. 10-1975972 (registered on April 30, 2019)

The purpose of the present invention is to provide a bipolar plate and stack for a redox flow battery that can improve the electrolyte distribution and pressure uniformity within the electrode of the redox flow battery, and a redox flow battery using the same.

Another object of the present invention is to provide a bipolar plate and stack for redox flow batteries that can improve the output, energy density and energy efficiency of redox flow batteries with large-area cells so that they can be used for industrial purposes, and a redox flow battery using the same. I'm doing it.

In order to achieve the above object, a bipolar plate for a redox flow battery according to an embodiment of the present invention is formed with a predetermined pattern in which one side is open in the flow path layer on one side of the electrode in the stack to form a path through which the electrolyte flows. multiple Euro channels; The distribution layer, which is spaced apart from the flow path layer by a predetermined distance, is formed with a pattern according to the arrangement positions of the plurality of flow channels and receives the electrolyte flowing into the plurality of flow channels or discharged from the plurality of flow channels from the outside. Two distribution channels for discharge to the outside; and a plurality of inter-layer flow paths connecting the two distribution channels formed in the distribution layer and the input and output ends of the plurality of flow channels formed in the flow path layer, respectively.

The two distribution passages include: a first distribution passage having one end open toward the side of the bipolar plate to form an injection port and formed in a pattern passing through positions corresponding to input ends of the plurality of flow channels; And it may include a second distribution passage, one end of which is open toward the side of the bipolar plate to form an outlet, and which is formed to pass through a position corresponding to the output end of the plurality of flow channels.

The plurality of inter-layer flow paths are formed to connect the input terminals of each of the first distribution passage and the plurality of flow channels, and supply the electrolyte flowing into the first distribution passage to each of the plurality of flow channels. Euro; and a plurality of second interlayer flow paths formed to connect the second distribution path and output terminals of each of the plurality of flow channels, and transferring the electrolyte recovered from each of the plurality of flow channels to the second distribution path. there is.

The plurality of flow channels may be formed in the same predetermined pattern and evenly distributed on one surface of the bipolar plate.

Each of the plurality of flow channels has one input end connected to the first interlayer flow path and an output end of the other end connected to the second interlayer flow path to receive the electrolyte supplied through the first distribution path and to dispense the electrolyte. 2 A single channel discharging into the distribution channel can be formed as a sand flow channel with a repeatedly bent zigzag pattern.

Each of the plurality of flow channels has one end connected to the first interlayer flow path, a plurality of first flow channels that receive the electrolyte supplied through the first distribution passage, and one end connected to the second interlayer flow path, The second flow channel, which discharges the electrolyte introduced through the electrode into the second distribution passage, may be formed as an interdigitated flow channel having an alternating pattern spaced apart from each other.

A stack for a redox flow battery according to another embodiment of the present invention to achieve the above object includes an ion exchange membrane; two electrodes disposed on both sides of the ion exchange membrane to generate a chemical reaction of the supplied electrolyte when electrolyte is supplied; And at least one bipolar plate disposed on one side of each of the two electrodes to supply the electrolyte transferred from the electrolyte circulation path to the corresponding electrode and discharge the electrolyte recovered from the corresponding electrode to the circulation path. Unit cells are implemented by stacking, and each of the two bipolar plates is formed with a predetermined pattern in which one side is open in the flow path layer on one side toward the electrode, and a plurality of flow channels are formed to form a path through which electrolyte flows; The distribution layer, which is spaced apart from the flow path layer by a predetermined distance, is formed with a pattern according to the arrangement positions of the plurality of flow channels and receives the electrolyte flowing into the plurality of flow channels or discharged from the plurality of flow channels from the outside. Two distribution channels for discharge to the outside; and a plurality of inter-layer flow paths connecting the two distribution channels formed in the distribution layer and the input and output ends of the plurality of flow channels formed in the flow path layer, respectively.

A redox flow battery according to another embodiment of the present invention for achieving the above object includes two tanks each storing the electrolyte of the anolyte and the electrolyte of the catholyte; An ion exchange membrane and two electrodes disposed on both sides of the ion exchange membrane to generate a chemical reaction of the supplied electrolyte when electrolyte is supplied from the two tanks, and disposed on one side of each of the two electrodes and transmitted in the electrolyte circulation path A stack of at least one unit cell each including two bipolar plates that supply electrolyte to a corresponding electrode and discharge electrolyte recovered from the corresponding electrode into a circulation path; and a plurality of pumps that circulate the electrolyte along a circulation path between the two tanks and the stack, wherein each of the two bipolar plates has a predetermined pattern with one side open in the flow path layer on one side in the electrode direction. A plurality of flow channels are formed to form a path through which electrolyte flows; The distribution layer, which is spaced apart from the flow path layer by a predetermined distance, is formed with a pattern according to the arrangement positions of the plurality of flow channels and receives the electrolyte flowing into the plurality of flow channels or discharged from the plurality of flow channels from the outside. Two distribution channels for discharge to the outside; and a plurality of inter-layer flow paths connecting the two distribution channels formed in the distribution layer and the input and output ends of the plurality of flow channels formed in the flow path layer, respectively.

Therefore, the bipolar plate and stack for redox flow batteries according to an embodiment of the present invention, and the redox flow battery using the same, have a three-dimensional flow path structure formed on the bipolar plate to uniformly and smoothly supply electrolyte to a plurality of flow paths. In industrial redox flow batteries with large-area cells, power, energy density, and energy efficiency can be improved by improving electrolyte distribution and pressure uniformity within the electrode.

Figure 1 shows an example of a redox flow battery configuration.
Figure 2 shows the flow path structure formed in the bipolar plate and the electrolyte flow path according to the flow path structure.
Figure 3 shows another example of a flow channel pattern.
Figure 4 shows an example of a bipolar plate on which a flow channel is formed according to an embodiment of the present invention.
Figure 5 shows a cross-sectional view to explain the distribution layer and flow path layer in the bipolar plate of Figure 4.
Figure 6 is a diagram for explaining the arrangement structure of the distribution layer and flow path layer in a stack in which multiple unit cells are stacked.
Figure 7 shows another example of a bipolar plate with flow channels formed according to an embodiment of the present invention.
FIG. 8 shows a cross-sectional view of the flow path layer for explaining the flow path pattern of the flow channel formed in the bipolar plate of FIG. 7.

In order to fully understand the present invention, its operational advantages, and the objectives achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the described embodiments. In order to clearly explain the present invention, parts that are not relevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain element, this does not mean excluding other elements, unless specifically stated to the contrary, but rather means that it may further include other elements. In addition, terms such as "... unit", "... unit", "module", and "block" used in the specification refer to a unit that processes at least one function or operation, which is hardware, software, or hardware. and software.

Figure 1 shows an example of a redox flow battery configuration.

Figure 1 shows the schematic structure of a vanadium redox flow battery as an example of a flow battery. Referring to Figure 1, the flow battery consists of two tanks (11, 12) and two tanks (11, 12) in which the liquid positive electrode electrolyte (Analyte) (13) and the negative electrode electrolyte (Catholyte (14)) are stored, respectively. The anolyte 13 and catholyte 14 flowing from the tank through the pipe, which is the electrolyte circulation path, undergo chemical reactions such as oxidation/reduction to obtain power or generate a chemical reaction based on the obtained power. When charging or discharging the stack 20, the anolyte 13 and catholyte 14 stored in the corresponding one of the two tanks 11 and 12 are circulated through the stack 20 through a pipe that is a circulation path. It includes two pumps (15, 16) and a load (17) that uses the power generated by the stack (20) when discharging or a power source (not shown) that supplies power to the stack (20) when charging. can do.

In FIG. 1, (b) is a separate drawing showing the detailed configuration of the stack 20. Generally, the stack 20 is composed of a plurality of cells stacked, but here, for convenience of explanation, the stack 20 includes one cell. It is shown assuming that cells are included.

As shown in (b), each cell of the stack 20 has an anode and a cathode on both sides with an ion exchange membrane (ion exchange membrane or ion selective membrane) 21 having selective permeability in between. It is composed. The ion exchange membrane 21 maintains the anolyte 13 and the cathode 14 separated from the anode and cathode and allows ions to selectively move between the anode and cathode during charging or discharging. This causes a chemical reaction to occur at the anode and cathode respectively.

The anode portion and the cathode portion each include an electrode 23, a bipolar plate 24, and a current collector 26, and have a configuration that is symmetrical to each other with respect to the ion exchange membrane 21.

The electrodes 23 located on both sides of the ion exchange membrane 21 are reaction electrodes that cause an oxidation/reduction reaction between the anolyte 13 and the catholyte 14 and ions, and the oxidation/reduction reaction occurs at the interface of the electrodes. Therefore, it is implemented as a porous electrode to increase the reaction area. At this time, the electrode 23 may be placed within the frame 22 to prevent leakage of the anolyte 13 and catholyte 14 flowing into the electrode.

And the bipolar plate 24 is configured to store the anolyte 13 and catholyte supplied from the two tanks 11 and 12 by the pumps 15 and 16 according to the structure of the flow channel 25 formed in advance according to a predetermined pattern. (14) is supplied to each corresponding electrode (23), while the anolyte (13) and catholyte (14) re-introduced from the corresponding electrode (23) are recovered back to the two tanks (11, 12). do. Here, the flow channel 25 is formed to allow the anolyte 13 and catholyte 14 to circulate smoothly even at low pressure and flow evenly throughout one surface of the porous electrode 23. Accordingly, the anolyte and catholyte react with the porous electrode 23 while circulating between the stack 20 and the two tanks 11 and 12 by the pumps 15 and 16. Here, the flow channel 25 is generally formed in the form of a groove according to a predetermined pattern on one surface of the bipolar plate 24 that contacts the electrode 23.

The current collector 26 is a charge movement path that transfers charges collected from the electrode 23 during discharge to the load 17, and supplies charges applied from a power source (not shown) to the electrode 23 during charging.

Additionally, endplates 27 may be disposed at both ends of the stack to secure and protect at least one unit cell included.

Figure 2 shows the structure of the flow channel formed in the bipolar plate and the flow path of the electrolyte according to the flow channel structure.

In Figure 2, (a) shows a case where a serpentine flow channel 25 is formed in the bipolar plate 24, and (b) shows an interdigitated flow channel 25-2, 25- 3) indicates the case in which it is formed. And (c) is through the porous electrode 23 while the electrolyte of the anolyte 13 or catholyte 14 flowing into the inlet of the sand flow channel 25-1 is discharged to the outlet. Shows the flow path, and (d) shows that the electrolytes 13 and 14 applied to the inlet of the first flow channel 25-2 are discharged to the outlet of the second flow channel 25-3. It shows the path flowing through the porous electrode 23.

Here, for convenience of explanation, the shape of the bipolar plate 24 is omitted, and the electrode 23 located on one side of the ion exchange membrane 21 and the flow channels 25-1 and 25-2 formed in the bipolar plate 24 , 25-3) is shown, but the flow channels 25-1, 25-2, and 25-3 may also be combined on one surface of the electrode 23 located on the other side.

As shown in FIG. 1, since the bipolar plate 24 and the electrode 23 are disposed adjacently in the stack 20, the flow channels 25-1, 25-2, and 25-3 are as shown in FIG. 3. As shown in (a) to (d), it is placed on one side of the electrode 23.

As shown in (a) and (c) of Figure 2, the sand flow channel 25 is formed as a groove in a zigzag pattern in which a single channel is repeatedly bent on one side of the bipolar plate 24, so that certain areas in the channel are formed. are located parallel to each other. Then, the electrolyte applied to the inlet of the serpentine channel 25-1 formed on one surface of the porous electrode 23 flows and is discharged along the formed channel pattern to the outlet. At this time, as shown in (c), the electrolyte flowing into the sand-shaped flow channel 25-1 not only flows along the channel pattern, but also flows through the open side of the sand-shaped flow channel 25-1 to the electrode 23. flows into. Accordingly, the electrolyte flows through the electrode 23 in the rib section between channel regions located adjacent to each other and can be transferred to other regions on the flow channel 25-1.

And as shown in Figures 2 (b) and (d), the pod-shaped flow channel is a pattern in which two flow channels (25-2, 25-3) having a comb-shaped pattern are engaged with each other. It is formed in a pattern in which the comb teeth of the two flow channels 25-2 and 25-3 are positioned alternately. Here, an inlet is formed in the input flow channel 25-2 through which electrolyte flows, and an outlet is formed in the output flow channel 25-3. Therefore, as shown in (d), the electrolyte supplied to the input flow channel 25-2 is supplied to the output flow channel 25-3 through the electrode 23 and discharged again.

Accordingly, in the sand-shaped flow channel 25-1, the electrolyte flows into the electrode 23 while flowing along the channel from the inlet to the outlet of the flow channel 25-1, so some electrolyte flows into the electrode 23, whereas in the pod-shaped channel 25-1, some electrolyte flows into the electrode 23. In the flow channels 25-2 and 25-3, the input flow channel 25-2 with an inlet and the output flow channel 25-3 with an outlet have a separate structure, so the electrolyte is formed in the porous electrode 23. It has a structure in which it is transmitted from the input flow channel 25-2 to the output flow channel 25-3.

Figure 3 shows another example of a flow channel pattern.

As mentioned above, in recent years, as high-output and large-capacity redox flow batteries have been required, the area of the unit cell itself has increased significantly. As a result, even if the electrolyte forms a flow channel as shown in (a) and (b) of Figure 2, the electrode ( There is a problem that the electrolyte is not supplied equally to the entire surface of 23), and the pressure must be increased to ensure a stable supply of the electrolyte. To solve this problem, a branch pattern was introduced in Figures 3 (a) to (c). In Figure 3 (a) is a case in which a sand-shaped flow channel is formed as in Figure 2 (a). Here, three sand-shaped flow channels (A, B, C) are formed, and three sand-shaped flow channels (A, B, C) shares the inlet and outlet. At this time, the inlets of the sandy conduit channels (A, B, C) branched directly from the inlet, but the outlets were connected first to the outlets of the two sandy conduit channels (A, B), and then connected to the outlets of the remaining sandy conduit channels (C). It has a combined structure.

In FIG. 3 , (b) and (c) both show cases where pod-shaped flow channels such as (b) in FIG. 2 are formed. In (b), electrolyte flows in through the two main input channels located at both ends, and in (c), electrolyte flows in through the main input channel located at the top and is delivered to the first input branch channel. And the electrolyte flowing into the first input branch channel is again transferred to the second input branch channel. The electrolyte flowing into the secondary input branch channel is delivered to the secondary output branch channel through the electrode 23, and the electrolyte delivered to the secondary output branch channel is applied to the main output channel through the primary output branch channel and is discharged to the outlet. is discharged. At this time, the primary input and output channels have a larger cross-sectional area than the secondary input and output branch channels, and the main input and output channels are formed to have a larger cross-sectional area than the primary input and output branch channels so that the electrolyte flows through all paths of the flow channel as much as possible. Make sure it flows evenly.

The branching pattern of the flow channel formed in the bipolar plate 24 as shown in FIG. 3 allows electrolyte to flow evenly into the entire area of the electrode 23 even at low pressure, thereby improving the energy efficiency of the flow battery. However, if the unit cell area of the stack 20 increases significantly, even if a branching pattern is used, the size of each branched flow channel increases, causing pressure and concentration differences in the electrolyte at each location, which may lower energy efficiency. Additionally, the pattern design of the branch channels for distributing and collecting the electrolyte becomes complicated, making it difficult to uniformly distribute the electrolyte to the electrodes. This is because the flow channel is formed only on a single surface of the bipolar plate 24 as shown in FIGS. 2 and 3, so the branch paths must be designed so that they do not overlap each other.

Figure 4 shows an example of a bipolar plate with a flow channel formed therein according to an embodiment of the present invention, and Figure 5 shows a cross-sectional view for explaining the distribution layer and the flow path layer in the bipolar plate of Figure 4.

Referring to Figures 4 and 5, the bipolar plate 24 according to this embodiment is also coupled to the electrode 23. However, the bipolar plate 24 of the present embodiment is spaced apart from the flow path layer 310 on which the flow channel 311 is formed on one side and the flow path layer 310 at a predetermined interval between one side and the other side of the bipolar plate 24. It may be divided into a distribution layer 320 in which a distribution channel 311 is formed.

The flow channel 311 formed in the flow path layer 310 is formed in the form of a groove open in the electrode direction on one side of the bipolar plate 24, as before. At this time, the flow channels 251 are separated from each other and dispersed to form a plurality. That is, in this embodiment, a plurality of distinct flow channels 311 are distributed and formed on one surface of the bipolar plate 24. Figure 4 shows an example in which three shaped flow channels 311 are formed, but since the number and pattern shape of the flow channels 311 are not limited, they may also be formed as pod-shaped flow channels or other patterned flow channels. . However, when the plurality of flow channels 311 are formed in different pattern shapes, it is difficult to uniformly supply electrolyte to each area of the electrode 23, so as shown in FIG. 4, the plurality of flow channels 311 are formed in the same pattern shape. It is preferable to be formed as

And in each of the plurality of flow channels 311, one end is an input end that receives electrolyte and the other end is an output end that discharges electrolyte. In this embodiment, the input end and output end of the plurality of flow channels 311 are bipolar in the flow path layer 310. It is not connected to the side of the plate (24). That is, in the flow path layer 310, each of the plurality of flow channels 311 is completely separated from each other and has a closed, independent structure, but instead has first and second interlayer flow paths formed between the flow path layer 310 and the distribution layer 320 ( 331, 332).

Meanwhile, the distribution layer 320 has a first distribution passage 321 for distributing the electrolyte flowing into the injection port formed at one end to each of the plurality of flow channels 311 and collects the electrolyte flowing out from the plurality of flow channels 311. Thus, a second distribution passage 322 is formed for discharging to an outlet formed at one end. The first distribution path 321 is formed in a pattern passing through positions corresponding to the positions of the input terminals of each of the plurality of flow channels 311 within the distribution layer 320, and the second distribution path 322 is formed of a plurality of flow channels 311. (311) It is formed in a pattern that passes through positions corresponding to the positions of each output terminal.

Meanwhile, each of the plurality of first interlayer flow paths 331 penetrates the flow path layer 310 and the distribution layer 320 to connect the input terminal of the corresponding flow channel among the plurality of flow channels 311 and the first distribution path 321. formed to do so. And each of the plurality of second interlayer flow paths 332 also penetrates the flow path layer 310 and the distribution layer 320 to connect the output end of the corresponding flow channel among the plurality of flow channels 311 and the second distribution path 322. formed to do so. At this time, the plurality of interlayer flow paths 331 and 332 may be formed to vertically pass through the flow path layer 310 and the distribution layer 320 as shown in FIG. 4, but is not limited thereto. As an example, a plurality of interlayer flow paths (331, 332) are connected to the flow path (310) so that the electrolyte can flow more easily between the flow channel (311) and the distribution path (311, 322). ) and the distribution layer 320 may be formed with a constant slope.

In this embodiment, the bipolar plate 24 supplies the electrolyte flowing into the inlet to a plurality of flow channels 311 for supplying and recovering electrolyte to the electrode 23 and a plurality of flow channels 311. The distribution channels 321 and 322 that discharge the electrolyte recovered from 311 to the outlet have a three-dimensional structure formed in different layers of the flow path layer 310 and the distribution layer 320, respectively. Therefore, since the distribution channels 321 and 322 are formed in the distribution layer 320 that is not determined by the pattern of the flow channel 311, the plurality of flow channels 311 are also patterned and arranged without considering the distribution and recovery path of the electrolyte. The position can be freely adjusted. Therefore, the flow channel 311 can be formed in various patterns that can uniformly supply electrolyte to the electrode 23.

In addition, when the flow channel 311 is formed as a pod-shaped flow channel with a branching pattern as shown in (b) or (c) of FIG. 3, a main input channel and a main output channel are formed in the distribution layer 320, and the flow channel Secondary input and output branch channels, which are terminal branch channels, may be formed in the layer 310. And, like the primary input and output branch channels, the intermediate branch channels may be formed in either the flow path layer 310 or the distribution layer 320. That is, the location of the intermediate branch channel may be formed in the flow path layer 310 or the distribution layer 320 in consideration of design convenience.

Figure 6 is a diagram for explaining the arrangement structure of the distribution layer and flow path layer in a stack in which multiple unit cells are stacked.

FIG. 6 shows a case where two unit cells C1 and C2 are stacked in the stack 200. As shown in FIG. 6, each of the two unit cells C1 and C2 has an ion exchange membrane 21 in the center, and electrodes 23 and bipolar plates 24 are disposed on both sides. In addition, in each bipolar plate 24, a plurality of flow channels 311 are formed in the flow path layer 310 on one side toward the electrode, and in the distribution layer 320 spaced apart from the flow path layer 310 within the bipolar plate 24. First and second distribution passages 321 and 322 are formed at one end of each of which has an inlet or outlet that is open laterally of the bipolar plate 24. The first and second distribution channels 321 and 322 are connected to the input or output terminals of the plurality of flow channels 311 through interlayer flow paths 331 and 332, respectively.

Since the plurality of flow channels 311 are open in the direction of the electrode, the introduced electrolyte can be easily supplied in the direction of the electrode 23. However, since the first and second distribution channels 321 and 322 are formed inside the bipolar plate 24, the introduced electrolyte does not flow into the adjacent unit cells C1 and C2. Therefore, as shown in FIG. 6, even if a plurality of unit cells C1 and C2 are stacked in the stack 20, the plurality of unit cells C1 and C2 are independent power sources in which electrolyte is individually supplied and recovered and circulated. It can operate as a generating element.

Figure 7 shows another example of a bipolar plate with flow channels formed according to an embodiment of the present invention. FIG. 8 shows a cross-sectional view of the flow path layer for explaining the flow path pattern of the flow channel formed in the bipolar plate of FIG. 7.

In FIGS. 4 and 5, three flow channels 311 are formed in the bipolar plate 24, whereas in FIGS. 7 and 8, six flow channels 411 with relatively smaller sizes are formed in the bipolar plate 24. was formed. When a large number of small-sized flow channels 411 are arranged in this way, the electrolyte can be easily supplied even at a relatively low pressure compared to the large-sized flow channel 311, and the pressure imbalance between locations is reduced, thereby reducing the electrolyte. It can be supplied more evenly to the electrode 23.

In the case of the flow channels of FIGS. 2 and 3, in order to supply electrolyte to the large-area electrode 23, it is difficult to evenly supply electrolyte to multiple flow channels due to limitations in the distribution path design, so the size of the flow channels must be adjusted accordingly. must be increased. However, as shown in FIG. 7, in the bipolar plate 24 of this embodiment, the distribution paths 421 and 422 may be formed in various patterns separately in the distribution layer 320, which is different from the flow path layer 310 in which the flow channel is formed. Therefore, the number and arrangement position of the flow channels 411 can also be freely adjusted. Accordingly, instead of reducing the size of each of the plurality of flow channels 411, the number of flow channels can be increased so that the electrolyte can be easily supplied to the electrode through the flow channels 411 even at low pressure. In addition, there is no need to adjust the positions of the input and output terminals of the multiple flow channels 411 according to the distribution path, so as shown in FIGS. 7 and 8, the multiple flow channels 411 can all be designed in the same pattern. Therefore, the ease of pattern design is improved.

However, the first distribution passage 421 and the second distribution passage 422 equally formed in the distribution layer 320 must be designed so as not to intersect. Accordingly, in FIG. 7, as an example, the first distribution passage 421 and the second distribution passage 422 are formed. The distribution channels 422 are shown as being formed in a “L” shaped pattern. Here too, an inlet or outlet opening that opens toward the side of the bipolar plate 24 is formed at one end of each of the first and second distribution passages 421 and 422.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely illustrative, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached claims.

11, 12: Tank 13: Anolyte
14: catholyte 15, 16: pump
17: load 20: stack
21: ion exchange membrane 22: frame
23: electrode 24: bipolar plate
25: Euro Channel 26: All House
27: end plate 310: flow layer
320: Distribution layer 311, 411: Euro channel
321, 421: first distribution path 322, 422: second distribution path
331, 431: first inter-layer flow path 332, 432: second inter-layer flow path

Claims (19)

In the bipolar plate included in the flow battery stack,
A plurality of flow channels forming a path through which electrolyte flows by having a pattern in which one side is open in the flow path layer on one side of the electrode in the stack;
It is formed at a position according to the arrangement position of the plurality of flow channels in the distribution layer spaced apart from the flow path layer by a predetermined distance, and receives the electrolyte flowing into or discharged from the plurality of flow channels from the outside. Two distribution channels discharge into; and
A bipolar plate including two distribution channels formed in the distribution layer and a plurality of interlayer flow paths connecting input and output ends of a plurality of flow channels formed in the flow path layer. The method of claim 1, wherein the two distributions are
a first distribution path having one end open toward the side of the bipolar plate to form an injection port and formed in a pattern passing through positions corresponding to input ends of the plurality of flow channels; and
A bipolar plate, one end of which is open toward the side of the bipolar plate to form an outlet, and a second distribution passage formed to pass through a position corresponding to an output end of the plurality of flow channels. The method of claim 2, wherein the plurality of interlayer flow paths are
a plurality of first interlayer flow paths formed to connect input terminals of the first distribution path and each of the plurality of flow channels to supply electrolyte flowing into the first distribution path to each of the plurality of flow channels; and
A bipolar plate including a plurality of second interlayer flow paths formed to connect the second distribution path and output terminals of each of the plurality of flow channels and transferring the electrolyte recovered from each of the plurality of flow channels to the second distribution path. . The method of claim 3, wherein the plurality of flow channels are
A bipolar plate formed in the same predetermined pattern and evenly distributed on one surface of the bipolar plate. The method of claim 3, wherein each of the plurality of flow channels is
One input end is connected to the first interlayer flow path, and the other end is connected to the second interlayer flow path, so as to receive the electrolyte supplied through the first distribution passage and discharge the electrolyte into the second distribution passage. A bipolar plate formed by serpentine flow channels in which the channels have a zigzag pattern of repeated bends. The method of claim 2, wherein each of the plurality of flow channels is
A plurality of first flow channels that receive the electrolyte supplied through the first distribution passage and second flow channels that discharge the electrolyte introduced through the electrode into the second distribution passage are spaced apart from each other and are arranged in an alternating pattern. A bipolar plate formed with interdigitated flow channels. The method of claim 3, wherein each of the plurality of interlayer flow paths is
A bipolar plate formed with a predetermined slope between the distribution layer and the flow path layer. In the stack for flow batteries,
Ion exchange membrane;
two electrodes disposed on both sides of the ion exchange membrane to generate a chemical reaction of the supplied electrolyte when electrolyte is supplied; and
At least one unit each including two bipolar plates disposed on one side of each of the two electrodes to supply electrolyte transferred from the electrolyte circulation path to the corresponding electrode and discharge electrolyte recovered from the corresponding electrode to the circulation path. The cells are stacked and implemented,
Each of the two bipolar plates is
A plurality of flow channels forming a path through which electrolyte flows by having a pattern in which one side is open in the flow path layer on one side in the direction of the electrode;
It is formed at a position according to the arrangement position of the plurality of flow channels in the distribution layer spaced apart from the flow path layer by a predetermined distance, and receives the electrolyte flowing into or discharged from the plurality of flow channels from the outside. Two distribution channels discharge into; and
A stack for a flow battery comprising a plurality of interlayer flow paths connecting each of the two distribution channels formed in the distribution layer and the input and output ends of a plurality of flow channels formed in the flow path layer. The method of claim 8, wherein the two distributions are
a first distribution path having one end open toward the side of the bipolar plate to form an injection port and formed in a pattern passing through positions corresponding to input ends of the plurality of flow channels; and
A stack for a flow battery including a second distribution path, one end of which is open toward the side of the bipolar plate to form an outlet, and which is formed to pass through a position corresponding to an output end of the plurality of flow channels. The method of claim 9, wherein the plurality of interlayer flow paths are
a plurality of first interlayer flow paths formed to connect input terminals of the first distribution path and each of the plurality of flow channels to supply electrolyte flowing into the first distribution path to each of the plurality of flow channels; and
For a flow battery comprising a plurality of second interlayer flow paths formed to connect the second distribution path and an output terminal of each of the plurality of flow channels and transferring the electrolyte recovered from each of the plurality of flow channels to the second distribution path. stack. The method of claim 10, wherein the plurality of flow channels are
A stack for flow batteries formed in the same predefined pattern and evenly distributed on one surface of the bipolar plate. The method of claim 10, wherein each of the plurality of flow channels is
One input end is connected to the first interlayer flow path, and the other end is connected to the second interlayer flow path, so as to receive the electrolyte supplied through the first distribution passage and discharge the electrolyte into the second distribution passage. A stack for a flow cell formed of sand flow channels with a zigzag pattern in which the channels are repeatedly bent. The method of claim 9, wherein each of the plurality of flow channels is
A plurality of first flow channels that receive the electrolyte supplied through the first distribution passage and second flow channels that discharge the electrolyte introduced through the electrode into the second distribution passage are spaced apart from each other and are arranged in an alternating pattern. A stack for a flow battery formed with interdigitated flow channels. Two tanks each storing the electrolyte of the anolyte and the electrolyte of the catholyte;
An ion exchange membrane and two electrodes disposed on both sides of the ion exchange membrane to generate a chemical reaction of the supplied electrolyte when electrolyte is supplied from the two tanks, and disposed on one side of each of the two electrodes and transmitted in the electrolyte circulation path A stack of at least one unit cell each including two bipolar plates that supply electrolyte to a corresponding electrode and discharge electrolyte recovered from the corresponding electrode into a circulation path; and
comprising a plurality of pumps that circulate the electrolyte along a circulation path between the two tanks and the stack,
Each of the two bipolar plates is
A plurality of flow channels forming a path through which electrolyte flows by having a pattern in which one side is open in the flow path layer on one side of the electrode direction;
It is formed at a position according to the arrangement position of the plurality of flow channels in the distribution layer spaced apart from the flow layer by a predetermined distance, and receives the electrolyte flowing into or discharged from the plurality of flow channels from the outside. Two distribution channels discharge into; and
A flow battery comprising two distribution channels formed in the distribution layer and a plurality of interlayer flow paths respectively connecting the input and output ends of the plurality of flow channels formed in the flow path layer. The method of claim 14, wherein the two distributions are
a first distribution path having one end open toward the side of the bipolar plate to form an injection port and formed in a pattern passing through positions corresponding to input ends of the plurality of flow channels; and
A flow battery including a second distribution path, one end of which is open toward the side of the bipolar plate to form an outlet, and which is formed to pass through a position corresponding to an output end of the plurality of flow channels. The method of claim 15, wherein the plurality of interlayer flow paths are
a plurality of first interlayer flow paths formed to connect input terminals of the first distribution path and each of the plurality of flow channels to supply electrolyte flowing into the first distribution path to each of the plurality of flow channels; and
A flow battery comprising a plurality of second interlayer flow paths formed to connect the second distribution path and an output terminal of each of the plurality of flow channels and transferring the electrolyte recovered from each of the plurality of flow channels to the second distribution path. . The method of claim 16, wherein the plurality of flow channels are
A flow battery formed in the same predetermined pattern and evenly distributed and disposed on one surface of the bipolar plate. The method of claim 16, wherein each of the plurality of flow channels
One input end is connected to the first interlayer flow path, and the other end is connected to the second interlayer flow path, so as to receive the electrolyte supplied through the first distribution passage and discharge the electrolyte into the second distribution passage. A flow cell formed by serpentine flow channels with a zigzag pattern in which the channels are repeatedly bent. The method of claim 15, wherein each of the plurality of flow channels is
A plurality of first flow channels that receive the electrolyte supplied through the first distribution passage and second flow channels that discharge the electrolyte introduced through the electrode into the second distribution passage are spaced apart from each other and are arranged in an alternating pattern. A flow cell formed by interdigitated flow channels.