Flow battery pole plate, single battery and flow battery stack

Abstract

The utility model relates to a flow battery pole plate, a single battery and a flow battery stack. The flow battery pole plate comprises a plate body, the first end of the plate body is provided with a liquid inlet, and the second end of the plate body is provided with a liquid outlet; a liquid inlet flow channel and a liquid outlet flow channel are formed in the plate body, are arranged in a spaced mode in the second direction and do not communicate with each other; wherein the liquid inlet flow channel comprises a first main flow channel and a first branch flow channel which are communicated with each other, the first main flow channel is communicated with the liquid inlet, and the first branch flow channel is located at the end, away from the liquid inlet, of the first main flow channel; the liquid outlet flow channel comprises a second main flow channel and a second branch flow channel which communicate with each other, the second main flow channel communicates with the liquid outlet, and the second branch flow channel is located at the end, away from the liquid outlet, of the second main flow channel; the first direction and the second direction are perpendicular to each other and are respectively perpendicular to the thickness direction of the plate body. According to the technical scheme, the problem that the electrolyte ion concentration at the local position of the flow field in the flow battery is low can be solved, and the battery performance can be improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a liquid flow battery plate, a single cell and a liquid flow battery stack. Background Art

[0002] At present, in the field of energy storage technology, liquid flow batteries are usually used for large-scale energy storage. When liquid flow batteries are in use, the ion concentration in some local locations in the electrolyte flow field is too low, resulting in a large difference in the electrolyte ion concentration in the entire flow field, insufficient electrochemical reaction, and affecting battery performance. Summary of the invention

[0003] Based on this, the present application provides a liquid flow battery plate, a single cell and a liquid flow battery stack to improve the problem of low electrolyte ion concentration at a local position of the flow field in the liquid flow battery, which helps to improve battery performance.

[0004] According to one aspect of the present application, a flow battery plate is provided, comprising:

[0005] The plate body has a first end and a second end arranged opposite to each other along a first direction, the first end of the plate body is provided with a liquid inlet, and the second end of the plate body is provided with a liquid outlet; the plate body is provided with a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel and the liquid outlet flow channel are arranged at intervals along the second direction and are not connected to each other;

[0006] The liquid inlet channel includes a first main channel and a first branch channel connected to each other, the first main channel is connected to the liquid inlet, and the first branch channel is located at an end of the first main channel away from the liquid inlet; the liquid outlet channel includes a second main channel and a second branch channel connected to each other, the second main channel is connected to the liquid outlet, and the second branch channel is located at an end of the second main channel away from the liquid outlet;

[0007] The first direction, the second direction and the thickness direction of the plate body are perpendicular to each other.

[0008] In one embodiment, the extension direction of the first main flow channel is parallel to the first direction, and the extension direction of the first branch flow channel is set at an angle to the second direction;

[0009] The extension direction of the second main flow channel is parallel to the first direction, and the extension direction of the second branch flow channel is set at an angle to the second direction.

[0010] In one embodiment, the extension direction of the first branch flow channel is arranged at a first angle with the second direction, and the first angle is 30° to 45°; and / or

[0011] The extension direction of the second branch flow channel is arranged at a second angle with the second direction, and the first angle is 30° to 45°.

[0012] In one embodiment, the distance between each adjacent first main flow channel and the second main flow channel is equal to the distance between another adjacent first main flow channel and the second main flow channel.

[0013] In one embodiment, a plurality of liquid inlet channels and a plurality of liquid outlet channels are provided, and along the second direction, the plurality of liquid inlet channels and the plurality of liquid outlet channels are alternately arranged at intervals.

[0014] In one embodiment, along the second direction, a plurality of first main flow channels and a plurality of second main flow channels are evenly and alternately arranged.

[0015] In one of the embodiments, the plate body is further provided with a first drainage channel and a second drainage channel which are arranged opposite to each other along the first direction;

[0016] One side of the first drainage channel along the first direction is connected to the liquid inlet, and the other side is connected to multiple first main channels; one side of the second drainage channel along the first direction is connected to the liquid outlet, and the other side is connected to multiple second main channels.

[0017] In one embodiment, each liquid inlet channel includes a first main channel and at least one first branch channel; each liquid outlet channel includes a second main channel and at least one second branch channel.

[0018] In one embodiment, at least one liquid inlet flow channel includes two first branch flow channels; in the same liquid inlet flow channel, the two first branch flow channels are symmetrically arranged about the first reference plane; the first reference plane is a plane perpendicular to the second direction; and / or

[0019] At least one liquid outlet channel includes two second branch channels; in the same liquid outlet channel, the two second branch channels are symmetrically arranged with respect to a second reference plane; and the second reference plane is a plane perpendicular to the second direction.

[0020] In one embodiment, in the same liquid inlet channel, the ratio of the size of the first branch channel along the fourth direction to the size of the first main channel along the second direction is 1 / 3 to 1 / 2, and the fourth direction is perpendicular to the extension direction of the first branch channel; and / or

[0021] In the same liquid inlet channel, the ratio of the size of the first branch channel along the second direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 5 to 1 / 3.

[0022] In one embodiment, in the same liquid outlet channel, the ratio of the size of the second branch channel along the fifth direction to the size of the second main channel along the second direction is 1 / 3 to 1 / 2, and the fifth direction is perpendicular to the extension direction of the second branch channel; and / or

[0023] In the same liquid outlet channel, the ratio of the size of the second branch channel along the second direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 5 to 1 / 3.

[0024] In one embodiment, the plate body is further provided with an opening along a third direction and a receiving cavity communicated with the opening, and the receiving cavity is used to receive the porous medium;

[0025] Along the third direction, a liquid inlet channel and a liquid outlet channel are provided through the bottom wall of the accommodating cavity;

[0026] The third direction is parallel to the thickness direction of the plate.

[0027] In one embodiment, the accommodating chamber has a first side wall and a second side wall opposite to each other along a first direction, the first side wall is arranged close to the liquid inlet, and the second side wall is arranged close to the liquid outlet;

[0028] Wherein, in the same liquid inlet channel, the ratio of the shortest distance from the first branch channel to the second side wall along the first direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 2 to 1; and / or

[0029] In the same liquid outlet channel, the ratio of the shortest distance between the second branch channel and the first side wall along the first direction to the spacing between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 2 to 1.

[0030] In one embodiment, the porous medium is configured as carbon felt; and / or

[0031] The plate body has a first surface and a second surface which are arranged back to back along a third direction; the liquid inlet, the liquid outlet, the liquid inlet flow channel and the liquid outlet flow channel are all opened on the first surface, and the opening is located on the second surface.

[0032] In one embodiment, the plate body includes a plate frame and a flow channel plate, and an opening is provided through the plate frame; the thickness of the flow channel plate is less than the thickness of the plate frame, and the flow channel plate is located in the opening of the plate frame to define a accommodating cavity; the liquid inlet and the liquid outlet are opened on the plate frame, and the liquid inlet flow channel and the liquid outlet flow channel are provided through the flow channel plate.

[0033] According to another aspect of the present application, a single cell is provided, comprising a positive electrode assembly, an exchange membrane and a negative electrode assembly stacked in sequence;

[0034] Wherein, the positive electrode assembly comprises a flow battery plate and a positive electrode as in any of the previous embodiments, and the positive electrode is arranged on a surface of the plate body on one side close to the liquid inlet and the liquid outlet along the third direction; and / or

[0035] The negative electrode assembly comprises a flow battery plate and a negative electrode as in any of the previous embodiments, wherein the negative electrode is disposed on a surface of the plate body on one side close to the liquid inlet and the liquid outlet along the third direction;

[0036] The third direction is parallel to the thickness direction of the plate.

[0037] According to another aspect of the present application, a liquid flow battery stack is provided, comprising a plurality of sub-stacks, each of the sub-stacks comprising a plurality of single cells as described in the aforementioned embodiments.

[0038] In the above-mentioned liquid flow battery plate and liquid flow battery, the liquid flow battery plate includes a plate body, one end of the plate body along the first direction is provided with a liquid inlet, and the other end is provided with a liquid outlet, the electrolyte is input through the liquid inlet, and the electrolyte is discharged through the liquid outlet. The plate body is provided with a liquid inlet flow channel and a liquid outlet flow channel; the liquid inlet flow channel and the liquid outlet flow channel are arranged at intervals along the second direction, so that the unreacted electrolyte can be infiltrated into the porous medium through the liquid inlet flow channel, and the reacted electrolyte can be infiltrated into the liquid outlet flow channel through the porous medium and discharged through the liquid outlet. By setting the liquid inlet flow channel to include a first main channel and a first branch flow channel connected to each other, the first branch flow channel is located at the end of the first main channel away from the liquid inlet, thus, the flow rate of the electrolyte penetrating from the end of the first main channel to the nearby porous medium can be shortened, so that the electrolyte can penetrate into the vicinity of the porous medium relatively faster at the end of the first branch flow channel; and by setting the liquid outlet flow channel to include a second main channel and a second branch flow channel connected to each other, the second branch flow channel is located at the end of the second main channel away from the liquid outlet, thus, the flow rate between the electrolyte at the end of the second main channel and the electrolyte on the nearby porous medium can be shortened, so that the electrolyte near the end of the second branch flow channel can penetrate to the end relatively faster, thereby reducing the overall flow resistance, improving the problem of too low electrolyte ion concentration at the end of the first main channel and the end of the second main channel in the flow field of the liquid flow battery plate, reducing the extreme difference in ion concentration, providing more space for subsequent current density increase and reduction of excess ratio, thereby helping to improve the performance of the liquid flow battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic structural diagram of a flow battery plate in one embodiment of the present application at a certain viewing angle.

[0040] FIG. 2 is a schematic diagram of the structure of the flow battery plate in FIG. 1 from another perspective.

[0041] FIG. 3 is a schematic diagram of the structure of the liquid flow battery plate in FIG. 1 from another viewing angle.

[0042] FIG. 4 is a schematic diagram of the local structure of point A in FIG. 2 .

[0043] FIG. 5 is a schematic diagram of the local structure of point B in FIG. 3 .

[0044] FIG. 6 is a schematic diagram of a partially exploded structure of a flow battery plate in an embodiment of the present application when applied to a single battery.

[0045] Figure 7aSchematic diagram of fluid mechanics simulation analysis of the flow battery plate in Figure 1.

[0046] Figure 7b It is a schematic diagram of the fluid mechanics simulation analysis of the liquid flow battery plate in the related art.

[0047] Description of Figure Numbers:

[0048] Liquid flow battery plate 100;

[0049] Plate body 110, liquid inlet channel 111, first main channel 111a, first branch channel 111b, liquid outlet channel 112, second main channel 112a, second branch channel 112b, first drainage channel 113, second drainage channel 114;

[0050] A first end z1, a second end z2, a liquid inlet k1, a liquid outlet k2, an opening u, a receiving cavity Q, and a second side wall e;

[0051] first angle w1, first dimension d1, second dimension d2, third dimension d3, spacing s1, shortest distance t1;

[0052] Porous medium 200;

[0053] Positive electrode 300;

[0054] Exchange membrane 400;

[0055] The first direction F1, the second direction F2, and the third direction F3. DETAILED DESCRIPTION

[0056] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0057] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0058] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0060] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0062] In the related art, the flow field of the flow battery adopts a simple staggered flow channel design, such as a rectangular, Z-shaped bend or S-shaped structure. The current simple staggered flow channel design is only based on the structure and the characteristics of reducing flow resistance. It can improve the uniformity of flow and ion concentration distribution and reduce the total flow resistance, but it does not solve the problem of low local concentration of electrochemical reaction due to the long process. Generally, in order to compensate for the low local concentration, the flow rate is often increased (the excess coefficient is increased), but it still cannot fundamentally solve the problem of low local ion concentration.

[0063] Based on this, the embodiments of the present application provide a liquid flow battery plate, a single cell and a liquid flow battery stack to improve the problem of low electrolyte ion concentration at a local position of the flow field in the liquid flow battery, which helps to improve battery performance.

[0064] Figure 1 shows a schematic diagram of the structure of a liquid flow battery plate in an embodiment of the present application at one viewing angle, Figure 2 shows a schematic diagram of the structure of the liquid flow battery plate in Figure 1 at another viewing angle, and Figure 3 shows a schematic diagram of the structure of the liquid flow battery plate in Figure 1 at yet another viewing angle. For ease of explanation, only the parts related to this embodiment are shown.

[0065] Referring to FIGS. 1 to 3, a flow battery plate 100 provided in an embodiment of the present application includes a plate body 110, the plate body 110 having a first end z1 and a second end z2 arranged opposite to each other along a first direction F1, the first end z1 of the plate body 110 having a liquid inlet k1, and the second end z2 of the plate body 110 having a liquid outlet k2; a liquid inlet channel 111 and a liquid outlet channel 112 are arranged on the plate body 110, and the liquid inlet channel 111 and the liquid outlet channel 112 are arranged at intervals along the second direction F2 and are not connected to each other; wherein the liquid inlet channel 111 includes a first main channel connected to each other The flow channel 111a and the first branch flow channel 111b, the first main flow channel 111a is connected to the liquid inlet k1, and the first branch flow channel 111b is located at the end of the first main flow channel 111a away from the liquid inlet k1; the liquid outlet flow channel 112 includes a second main flow channel 112a and a second branch flow channel 112b that are connected to each other, the second main flow channel 112a is connected to the liquid outlet k2, and the second branch flow channel 112b is located at the end of the second main flow channel 112a away from the liquid outlet k2; the first direction F1, the second direction F2 and the thickness direction of the plate body 110 are perpendicular to each other.

[0066] The plate body 110 is in the shape of a flat plate. The first direction F1 can be regarded as the length direction of the plate body 110, and the second direction F2 can be regarded as the width direction of the plate body 110. The plate body 110 has a first end z1 and a second end z2 arranged opposite to each other along the first direction F1, the first end z1 is provided with a liquid inlet k1, and the second end z2 is provided with a liquid outlet k2, the liquid inlet k1 is used to input unreacted electrolyte, and the liquid outlet k2 is used to discharge the reacted electrolyte. The plate body 110 is provided with a liquid inlet channel 111 and a liquid outlet channel 112, the liquid inlet channel 111 and the liquid outlet channel 112 are arranged at intervals along the second direction F2, and the liquid inlet channel 111 and the liquid outlet channel 112 are not connected to each other. The liquid inlet channel 111 refers to a channel for the unreacted electrolyte to flow through and penetrate into the porous medium 200, and the liquid outlet channel 112 refers to a channel for the reacted electrolyte that penetrates from the porous medium 200 to be discharged. In this embodiment, the porous medium 200 is configured as carbon felt.

[0067] Specifically, the liquid inlet channel 111 includes a first main channel 111a and a first branch channel 111b which are connected to each other. The first main channel 111a is connected to the liquid inlet k1, and the first branch channel 111b is located at an end of the first main channel 111a away from the liquid inlet k1, that is, the first branch channel 111b is arranged at a position far away from the electrolyte inlet process, and the end of the first main channel 111a away from the liquid inlet k1 is the end of the first main channel 111a. By arranging the first branch channel 111b at the end of the first main channel 111a, it helps to improve the low electrolyte ion concentration near the end of the first main channel 111a. The liquid outlet channel 112 includes a second main channel 112a and a second branch channel 112b that are connected to each other. The second main channel 112a is connected to the liquid outlet k2, and the second branch channel 112b is located at an end of the second main channel 112a away from the liquid outlet k2. That is, the second branch channel 112b is arranged at a position farther away from the electrolyte outlet process, and the end of the second main channel 112a away from the liquid outlet k2 is the end of the second main channel 112a. By arranging the second branch channel 112b at the end of the second main channel 112a, it helps to improve the low electrolyte ion concentration near the end of the second main channel 112a.

[0068] It should be noted that in this embodiment, the first mainstream channel 111a and the second mainstream channel 112a can both be rectangular in shape. In other embodiments, the first mainstream channel 111a can also be wavy or sawtooth in shape, and the second mainstream channel 112a can also be wavy or sawtooth in shape. The specific settings can be made according to actual conditions, and this embodiment does not limit this.

[0069] In this embodiment, by setting a first branch channel 111b at the end of the first main channel 111a of the liquid inlet channel 111, and by setting a second branch channel 112b at the end of the second main channel 112a of the liquid outlet channel 112, the process of the electrolyte penetrating from the end of the first main channel 111a to the nearby porous medium 200 can be shortened, so that the electrolyte can penetrate into the vicinity of the porous medium 200 relatively faster at the end of the first branch channel 111b; and the process between the electrolyte at the end of the second main channel 112a and the electrolyte on the nearby porous medium 200 can be shortened, so that the electrolyte near the end of the second branch channel 112b can penetrate to the end relatively faster, thereby reducing the overall flow resistance, improving the problem of too low electrolyte ion concentration at the end of the first main channel 111a and the end of the second main channel 112a in the flow field of the liquid flow battery plate, reducing the extreme difference in ion concentration, and providing more space for subsequent current density increase and reduction of excess ratio, thereby helping to improve the performance of the liquid flow battery.

[0070] Continuing to refer to Figure 2 and in combination with Figure 4, in some embodiments, the extension direction of the first main channel 111a is parallel to the first direction F1, and the extension direction of the first branch channel 111b is set at an angle to the second direction F2; the extension direction of the second main channel 112a is parallel to the first direction F1, and the extension direction of the second branch channel 112b is set at an angle to the second direction F2.

[0071] Specifically, the extension direction of the first main channel 111a can be regarded as the extension direction of the axis of the first main channel 111a. The extension direction of the first branch channel 111b can be regarded as the extension direction of the axis of the first branch channel 111b. The extension direction of the second main channel 112a can be regarded as the extension direction of the axis of the second main channel 112a. The extension direction of the second branch channel 112b can be regarded as the extension direction of the axis of the second branch channel 112b. The extension direction of the first branch channel 111b is set at a first angle w1 with the second direction F2. The first angle w1 refers to the angle between the extension direction of the first branch channel 111b and the second direction F2, and the first branch channel 111b can be roughly regarded as an inclined channel. The extension direction of the second branch channel 112b is set at a second angle with the second direction F2. The second angle refers to the angle between the extension direction of the second branch channel 112b and the second direction F2, and the second branch channel 112b can be roughly regarded as an inclined channel. In this way, the unreacted electrolyte flows at the end of the first main channel 111a along the inclined direction of the second direction F2 and along the first branch channel 111b to shorten the flow of the electrolyte from the end of the first main channel 111a to a nearby position (on the porous medium 200) as much as possible, and the reacted electrolyte flows from the end of the second main channel 112a along the inclined direction of the second direction F2 and along the second branch channel 112b to shorten the flow of the electrolyte from the end of the second main channel 112a to a nearby position (on the porous medium 200) as much as possible.

[0072] In some embodiments, the first angle w1 is 30° to 45°. Further, the second angle is 30° to 45°. For example, in a specific embodiment, the first angle w1 and the second angle are both set to 45°. In this way, optimizing the structural dimension parameters of the first branch flow channel 111b and the second branch flow channel 112b helps to uniformly increase the electrolyte ion concentration near the end of the first main flow channel 111a (on the porous medium 200), and helps to uniformly increase the electrolyte ion concentration near the end of the second main flow channel 112a (on the porous medium 200), thereby reducing the extreme difference in ion concentration.

[0073] In other specific embodiments, the first angle w1 can also be set to 30° or 40°, and the second angle can also be set to 30° or 40°, which can be set specifically according to actual conditions. In this way, the problem of low electrolyte ion concentration at a local position of the flow battery plate 100 can also be improved by reasonably setting the structural size parameters of the first branch flow channel 111b and the second branch flow channel 112b.

[0074] Continuing to refer to FIG. 2, in some embodiments, a plurality of liquid inlet channels 111 and a plurality of liquid outlet channels 112 are provided, and along the second direction F2, a plurality of liquid inlet channels 111 and a plurality of liquid outlet channels 112 are alternately arranged. Specifically, a plurality of liquid inlet channels 111 and a plurality of liquid outlet channels 112 are provided, and the specific number can be set according to actual conditions, and this embodiment is not limited here. Further, along the second direction F2, the spacing between each adjacent first main channel 111a and second main channel 112a is equal to the spacing between another adjacent first main channel 111a and second main channel 112a. In this way, the uniformity of the electrolyte ion concentration distribution in the liquid flow battery plate 100 can be improved, which helps to improve the performance of the liquid flow battery.

[0075] In some embodiments, the plate body 110 is further provided with a first drainage channel 113 and a second drainage channel 114 which are arranged opposite to each other along the first direction F1; the first drainage channel 113 is connected to the liquid inlet k1 on one side along the first direction F1, and is connected to multiple first main channels 111a on the other side; the second drainage channel 114 is connected to the liquid outlet k2 on one side along the first direction F1, and is connected to multiple second main channels 112a on the other side.

[0076] Specifically, the first drainage channel 113 refers to a channel connected to the liquid inlet k1 and multiple first main channels 111a. The second drainage channel 114 refers to a channel connected to multiple second main channels 112a and the liquid outlet k2. Each first main channel 111a is provided with an inlet connected to the first drainage channel 113, and each second main channel 112a is provided with an outlet connected to the second drainage channel 114. In this embodiment, the first drainage channel 113 is rectangular, and the second drainage channel 114 is rectangular. The extension direction of the first drainage channel 113 is parallel to the second direction F2, and the extension direction of the second drainage channel 114 is parallel to the second direction F2. In other embodiments, the shape and extension direction of the first drainage channel 113 and the second drainage channel 114 can be set according to actual conditions, and this embodiment is not limited here. In this way, the unreacted electrolyte can flow to the first drainage channel 113 through the liquid inlet k1, and be evenly distributed to the entrances of each first main channel 111a through the first drainage channel 113, thereby improving the uniformity of the electrolyte ion concentration distribution and improving the electrolyte flow distribution efficiency; and the reacted electrolyte can be converged to the second drainage channel 114 through the outlets of each second main channel 112a, and discharged from the liquid outlet k2 through the second drainage channel 114, thereby improving the electrolyte discharge efficiency.

[0077] Continuing to refer to FIG. 2, in some embodiments, each liquid inlet channel 111 includes a first main channel 111a and at least one first branch channel 111b; each liquid outlet channel 112 includes a second main channel 112a and at least one second branch channel 112b. Specifically, in this embodiment, the liquid inlet channel 111 may include a first main channel 111a and a first branch channel 111b, or the liquid inlet channel 111 includes a first main channel 111a and two first branch channels 111b, and the liquid outlet channel 112 may include a second main channel 112a and a second branch channel 112b, or the liquid outlet channel 112 includes a second main channel 112a and two second branch channels 112b. In other embodiments, the number of first branch channels 111b in the liquid inlet channel 111 and the number of second branch channels 112b in the liquid outlet channel 112 may be reasonably set according to actual needs. In this way, the structure of the liquid inlet channel 111 is reasonably arranged to improve the problem of low electrolyte ion concentration at a local position in the liquid flow battery plate 100, which is simple and efficient.

[0078] Continuing to refer to FIG. 2, in some embodiments, at least one liquid inlet channel 111 includes two first branch channels 111b; in the same liquid inlet channel 111, the two first branch channels 111b are symmetrically arranged with respect to the first reference plane; the first reference plane is a plane perpendicular to the second direction F2. Further, at least one liquid outlet channel 112 includes two second branch channels 112b; in the same liquid outlet channel 112, the two second branch channels 112b are symmetrically arranged with respect to the second reference plane; the second reference plane is a plane perpendicular to the second direction F2.

[0079] Specifically, in this embodiment, near the two sides of the plate body 110 along the second direction F2, the liquid inlet channel 111 includes a first main channel 111a and a first branch channel 111b, or the liquid outlet channel 112 includes a second main channel 112a and a second branch channel 112b, near the middle area of ​​the plate body 110, the liquid inlet channel 111 includes a first main channel 111a and two first branch channels 111b, and the liquid outlet channel 112 includes a second main channel 112a and two second branch channels 112b. In this embodiment, in the same liquid inlet channel 111, the two first branch channels 111b are symmetrically arranged with respect to the first reference plane, and in the same liquid outlet channel 112, the two second branch channels 112b are symmetrically arranged with respect to the second reference plane. In this way, the electrolyte ion concentration near the end of the first main channel 111a (on the porous medium 200) can be uniformly increased, and the electrolyte ion concentration near the end of the second main channel 112a on the porous medium 200 can be uniformly increased, reducing the extreme difference in ion concentration.

[0080] In other embodiments, in the same inlet flow channel 111, the two first branch flow channels 111b may be asymmetrically arranged about the first reference plane, and in the same outlet flow channel 112, the two second branch flow channels 112b may be asymmetrically arranged about the second reference plane. In this way, the problem of low electrolyte ion concentration at a local position of the flow battery plate 100 can be improved by reasonably arranging the structure of the inlet flow channel 111 and the structure of the outlet flow channel 112.

[0081] Continuing to refer to FIG. 2 to FIG. 4, in some embodiments, in the same liquid inlet channel 111, the ratio of the size of the first branch channel 111b along the fourth direction to the size of the first main channel 111a along the second direction F2 is 1 / 3 to 1 / 2, and the fourth direction is perpendicular to the extension direction of the first branch channel 111b. Further, in the same liquid inlet channel 111, the ratio of the size of the first branch channel 111b along the second direction F2 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is 1 / 5 to 1 / 3.

[0082] Specifically, the dimension of the first branch channel 111b along the fourth direction (i.e., the first dimension d1) can be regarded as the width of the first branch channel 111b, and the dimension of the first main channel 111a along the second direction F2 (i.e., the second dimension d2) can be regarded as the width of the first main channel 111a. In a specific embodiment, in the same inlet channel 111, the ratio of the width of the first branch channel 111b to the width of the first main channel 111a is set to 1 / 2, and the dimension of the first branch channel 111b along the second direction F2 (i.e., the third dimension d3) is set to 1 / 4, and the ratio of the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is set to 1 / 4. In this way, optimizing the structural dimension parameters of the first branch channel 111b helps to increase the electrolyte ion concentration near the end of the first main channel 111a (on the porous medium 200) and reduce the extreme difference in ion concentration.

[0083] In other specific embodiments, in the same outlet flow channel 112, the ratio of the width of the first branch flow channel 111b to the width of the first main flow channel 111a can be set to 1 / 3 or 2 / 5, etc., and the ratio of the size of the first branch flow channel 111b along the second direction F2 to the spacing s1 between the first main flow channel 111a and the second main flow channel 112a adjacent to each other along the second direction F2 can be set to 1 / 5 or 1 / 3, etc., which can be set specifically according to actual conditions. In this way, the reasonable setting of the structural size parameters of the first branch flow channel 111b can also improve the problem of low electrolyte ion concentration at a local position of the flow battery plate 100.

[0084] Continuing to refer to FIG. 2 to FIG. 4, in some embodiments, in the same liquid outlet channel 112, the ratio of the size of the second branch channel 112b along the fifth direction to the size of the second main channel 112a along the second direction F2 is 1 / 3 to 1 / 2, and the fifth direction is perpendicular to the extension direction of the second branch channel 112b. Further, in the same liquid outlet channel 112, the ratio of the size of the second branch channel 112b along the second direction F2 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is 1 / 5 to 1 / 3.

[0085] Specifically, the size of the second branch channel 112b along the fifth direction can be regarded as the width of the second branch channel 112b, and the size of the second main channel 112a along the second direction F2 can be regarded as the width of the second main channel 112a. In a specific embodiment, in the same outlet channel 112, the ratio of the width of the second branch channel 112b to the width of the second main channel 112a is set to 1 / 2, and the ratio of the size of the second branch channel 112b along the second direction F2 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent along the second direction F2 is set to 1 / 4. In this way, optimizing the structural size parameters of the second branch channel 112b helps to increase the electrolyte ion concentration near the end of the second main channel 112a (on the porous medium 200) and reduce the extreme difference in ion concentration.

[0086] In other specific embodiments, in the same outlet flow channel 112, the ratio of the width of the second branch flow channel 112b to the width of the second main flow channel 112a is set to 1 / 3 or 2 / 5, etc., and the ratio of the size of the second branch flow channel 112b along the second direction F2 to the spacing s1 between the first main flow channel 111a and the second main flow channel 112a adjacent along the second direction F2 is set to 1 / 5 or 1 / 3, etc., which can be set according to actual conditions. In this way, the structural size parameters of the second branch flow channel 112b are reasonably set, which can also improve the problem of low electrolyte ion concentration at a local position of the flow battery plate 100.

[0087] Continuing to refer to FIG. 3 , in some embodiments, the plate body 110 is further provided with an opening u along a third direction F3 and a receiving cavity Q connected to the opening u, the receiving cavity Q being used to accommodate the porous medium 200; along the third direction F3, a liquid inlet channel 111 and a liquid outlet channel 112 are penetrated on the bottom wall of the receiving cavity Q; the third direction F3 is parallel to the thickness direction of the plate body 110 .

[0088] Specifically, the plate body 110 is also provided with an opening u along the third direction F3 and a receiving cavity Q connected to the opening u, which can be roughly regarded as a groove structure provided on the plate body 110. The receiving cavity Q is used to place the porous medium 200, which is configured as carbon felt and has a plate shape. Along the thickness direction of the plate body 110, the bottom wall of the receiving cavity Q is penetrated by a liquid inlet channel 111 and a liquid outlet channel 112. In this way, the electrolyte in the liquid inlet channel 111 can penetrate into the porous medium 200, which helps the liquid flow battery to perform an electrochemical reaction, and the reacted electrolyte is discharged through the liquid outlet channel 112 to realize the energy storage function of the liquid flow battery.

[0089] Continuing to refer to FIG. 3 and in combination with FIG. 5 , in some embodiments, the accommodating chamber Q has a first side wall and a second side wall e opposite to each other along the first direction F1, the first side wall is arranged near the liquid inlet k1, and the second side wall e is arranged near the liquid outlet k2. Among them, in the same liquid inlet channel 111, the ratio of the shortest distance t1 of the first branch channel 111b from the second side wall e along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is 1 / 2 to 1. Furthermore, in the same liquid outlet channel 112, the ratio of the shortest distance of the second branch channel 112b from the first side wall along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is 1 / 2 to 1.

[0090] Specifically, the first side wall and the second side wall e both refer to the inner wall of the accommodating cavity Q arranged along the first direction F1, the first side wall is closer to the liquid inlet k1, and the second side wall e is closer to the liquid outlet k2. In a specific embodiment, in the same liquid inlet channel 111, the ratio of the shortest distance t1 of the first branch channel 111b from the second side wall e along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is set to 3 / 4, and the ratio of the shortest distance of the second branch channel 112b from the first side wall along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent to each other along the second direction F2 is set to 3 / 4. In this way, optimizing the structural size parameters of the first branch channel 111b and the second branch channel 112b helps to uniformly increase the electrolyte ion concentration near the end of the first main channel 111a (on the porous medium 200), helps to uniformly increase the electrolyte ion concentration near the end of the second main channel 112a (on the porous medium 200), and reduces the extreme difference in ion concentration.

[0091] In other specific embodiments, in the same liquid inlet channel 111, the ratio of the shortest distance t1 of the first branch channel 111b from the second side wall e along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent along the second direction F2 can be set to 1 / 2 or 1, etc., and the ratio of the shortest distance of the second branch channel 112b from the first side wall along the first direction F1 to the spacing s1 between the first main channel 111a and the second main channel 112a adjacent along the second direction F2 can be set to 1 / 2 or 1, etc., which can be specifically set according to the air permeability of the porous medium 200. The greater the air permeability of the porous medium 200, the greater the shortest distance t1 can be set. In this way, the reasonable setting of the structural size parameters of the first branch channel 111b and the second branch channel 112b can also improve the problem of low electrolyte ion concentration at a local position of the flow battery plate 100.

[0092] Continuing to refer to FIG. 2 and FIG. 3, and in combination with FIG. 6, in some embodiments, the plate body 110 has a first surface and a second surface that are arranged back to back along the third direction F3; the liquid inlet k1, the liquid outlet k2, the liquid inlet flow channel 111 and the liquid outlet flow channel 112 are all opened on the first surface, and the opening u is located on the second surface. Specifically, the first surface is used to stack the positive electrode 300 or the negative electrode, the second surface is used to stack the exchange membrane 400, and the porous medium 200 is located in the accommodation cavity Q. In this way, it is convenient to assemble the plate body 110 with the positive electrode 300 or the negative electrode to realize the energy storage function of the flow battery.

[0093] Continuing to refer to Figures 2 and 3, in some embodiments, the plate body 110 includes a plate frame and a flow channel plate, and an opening u is provided through the plate frame; the thickness of the flow channel plate is less than the thickness of the plate frame, and the flow channel plate is located in the opening u of the plate frame to define the accommodating cavity Q; the liquid inlet k1 and the liquid outlet k2 are opened on the plate frame, and the liquid inlet channel 111 and the liquid outlet channel 112 are provided through the flow channel plate.

[0094] Specifically, the flow channel plate refers to a plate structure for providing an inlet flow channel 111 and an outlet flow channel 112. The plate frame refers to a plate-shaped frame for accommodating the flow channel plate and the porous medium 200. In this embodiment, by setting the thickness of the flow channel plate to be less than the thickness of the plate frame, so that the flow channel plate is located in the opening u of the plate frame, a accommodating chamber Q can be defined, and the accommodating chamber Q is used to accommodate the porous medium 200. The liquid inlet k1 and the first drainage channel 113 are provided at one end of the plate frame along the first direction F1, and the liquid outlet k2 and the second drainage channel 114 are provided at the other end of the plate frame along the first direction F1. The liquid inlet flow channel 111 and the liquid outlet flow channel 112 are provided through the flow channel plate. Further, the plate frame and the flow channel plate are constructed as a split structure. In this way, by setting a split plate body 110, it is easy to manufacture, and it is also easy to install and disassemble. Alternatively, the flow channel plate and the plate frame are constructed as an integrated structure. In this way, the structural strength of the plate body 110 can be improved.

[0095] See also Figure 7a and Figure 7b In this embodiment, fluid mechanics simulation software is used to perform fluid mechanics simulation analysis on the electrolyte in the flow battery plate of the embodiment of the present application, and fluid mechanics simulation analysis on the electrolyte in the flow battery plate of the related art, and the electrolyte ion concentration at the liquid inlet is set to 1000 mol / m 3 , the electrolyte current density in the porous medium region is 100 mA / cm 2 The initial value of the flow resistance between the flow channels is set to 3 kPa. Through simulation analysis, it is found that the lowest local electrolyte ion concentration in the flow battery plate of the related technology is 910 mol / m 3 , while the lowest local electrolyte ion concentration in the flow battery plate of the present embodiment is 944 mol / m 3 , can effectively improve the problem of low local electrolyte ion concentration in the flow field of the liquid flow battery plate, provide more space for subsequent current density improvement and reduction of excess ratio, and thus help improve the performance of the liquid flow battery.

[0096] Continuing to refer to Figures 1 to 6, based on the same inventive concept, the embodiment of the present application also provides a single battery, including a positive electrode assembly, an exchange membrane 400 and a negative electrode assembly stacked in sequence. Among them, the positive electrode assembly includes a flow battery plate 100 and a positive electrode 300 as in any of the previous embodiments, and the positive electrode 300 is arranged on the surface of the plate body 110 along the third direction F3 close to the liquid inlet k1 and the liquid outlet k2. Further, the negative electrode assembly includes a flow battery plate 100 and a negative electrode as in any of the previous embodiments, and the negative electrode is arranged on the surface of the plate body 110 along the third direction F3 close to the liquid inlet k1 and the liquid outlet k2; the third direction F3 is parallel to the thickness direction of the plate body 110.

[0097] Specifically, both the positive electrode 300 and the negative electrode can be constructed as a plate-like structure, and the positive electrode assembly includes a plate body 110, a porous medium 200 and a positive electrode 300, the first surface of the plate body 110 is stacked with the positive electrode 300, the second surface of the plate body 110 is stacked with one side of the exchange membrane 400, and the porous medium 200 is accommodated in the accommodation cavity Q of the plate body 110 and is located between the exchange membrane 400 and the plate body 110. The negative electrode assembly includes a plate body 110, a porous medium 200 and a negative electrode, the first surface of the plate body 110 is stacked with the negative electrode, the second surface of the plate body 110 is stacked with the other side of the exchange membrane 400, and the porous medium 200 is located in the accommodation cavity Q of the plate body 110 and is located between the exchange membrane 400 and the plate body 110.

[0098] In this way, the energy storage function of a single cell is realized by assembling the plate body 110 with the positive electrode 300 or the negative electrode. In addition, by setting the first branch flow channel 111b in the plate body 110, the process of the electrolyte penetrating from the end of the first main flow channel 111a to the nearby porous medium 200 can be shortened, and the second branch flow channel 112b can shorten the flow of the electrolyte from the end of the second main flow channel 112a to the electrolyte on the nearby porous medium 200, thereby reducing the overall flow resistance, thereby improving the problem of low local current density in the flow channel, reducing the extreme difference in ion concentration, and providing more space for subsequent current density improvement and reduction of excess ratio, thereby helping to improve the performance of the liquid flow battery.

[0099] Based on the same inventive concept, the embodiment of the present application also provides a liquid flow battery stack, including multiple sub-stacks, each sub-stack including multiple single cells as in the above embodiment. Specifically, each sub-stack includes multiple single cells connected in series. In this way, by assembling multiple single cells as in the above embodiment, the energy storage function of the liquid flow battery can be realized, and at the same time, the problem of low electrolyte ion concentration at a local position of the flow field in the liquid flow battery can be improved, which helps to improve battery performance.

[0100] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A liquid flow battery plate, characterized in that: include: A plate body having a first end and a second end arranged opposite to each other along a first direction, wherein the first end of the plate body is provided with a liquid inlet, and the second end of the plate body is provided with a liquid outlet; a liquid inlet flow channel and a liquid outlet flow channel are provided on the plate body, and the liquid inlet flow channel and the liquid outlet flow channel are arranged at intervals along the second direction and are not connected to each other; The liquid inlet channel comprises a first main channel and a first branch channel connected to each other, the first main channel is connected to the liquid inlet, and the first branch channel is located at an end of the first main channel away from the liquid inlet; the liquid outlet channel comprises a second main channel and a second branch channel connected to each other, the second main channel is connected to the liquid outlet, and the second branch channel is located at an end of the second main channel away from the liquid outlet; The first direction, the second direction, and the thickness direction of the plate body are perpendicular to each other.

2. The liquid flow battery plate according to claim 1, characterized in that: The extension direction of the first main flow channel is parallel to the first direction, and the extension direction of the first branch flow channel is set at an angle to the second direction; An extension direction of the second main flow channel is parallel to the first direction, and an extension direction of the second branch flow channel is arranged at an angle to the second direction.

3. The liquid flow battery plate according to claim 2, characterized in that: The extending direction of the first branch flow channel is arranged at a first angle with the second direction, and the first angle is 30° to 45°; and / or The extension direction of the second branch flow channel is arranged at a second angle with the second direction, and the first angle is 30° to 45°.

4. The liquid flow battery plate according to claim 1, characterized in that: There are multiple liquid inlet channels and multiple liquid outlet channels, and along the second direction, the multiple liquid inlet channels and the multiple liquid outlet channels are alternately arranged at intervals.

5. The liquid flow battery plate according to claim 3, characterized in that: Along the second direction, a distance between each adjacent first main flow channel and second main flow channel is equal to a distance between another adjacent first main flow channel and second main flow channel.

6. The liquid flow battery plate according to claim 4, characterized in that: The plate body is further provided with a first drainage channel and a second drainage channel which are arranged opposite to each other along the first direction; The first drainage channel is connected to the liquid inlet on one side along the first direction, and connected to multiple first main channels on the other side; the second drainage channel is connected to the liquid outlet on one side along the first direction, and connected to multiple second main channels on the other side.

7. The liquid flow battery plate according to claim 4, characterized in that: Each of the liquid inlet flow channels includes one of the first main flow channels and at least one of the first branch flow channels; each of the liquid outlet flow channels includes one of the second main flow channels and at least one of the second branch flow channels.

8. The liquid flow battery plate according to claim 7, characterized in that: At least one of the liquid inlet flow channels comprises two of the first branch flow channels; in the same liquid inlet flow channel, the two first branch flow channels are symmetrically arranged about a first reference plane; the first reference plane is a plane perpendicular to the second direction; and / or At least one of the liquid outlet channels includes two second branch channels; in the same liquid outlet channel, the two second branch channels are symmetrically arranged with respect to a second reference plane; and the second reference plane is a plane perpendicular to the second direction.

9. The liquid flow battery plate according to claim 5, characterized in that: In the same liquid inlet channel, the ratio of the size of the first branch channel along the fourth direction to the size of the first main channel along the second direction is 1 / 3 to 1 / 2, and the fourth direction is perpendicular to the extension direction of the first branch channel; and / or In the same liquid inlet channel, the ratio of the size of the first branch channel along the second direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 5 to 1 / 3.

10. The liquid flow battery plate according to claim 5, characterized in that: In the same liquid outlet channel, the ratio of the size of the second branch channel along the fifth direction to the size of the second main channel along the second direction is 1 / 3 to 1 / 2, and the fifth direction is perpendicular to the extension direction of the second branch channel; and / or In the same liquid outlet channel, the ratio of the size of the second branch channel along the second direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 5 to 1 / 3.

11. The liquid flow battery plate according to any one of claims 1 to 10, characterized in that: The plate body is further provided with an opening along a third direction and a receiving cavity communicated with the opening, wherein the receiving cavity is used to receive the porous medium; Along the third direction, the bottom wall of the accommodating cavity is penetrated by the liquid inlet channel and the liquid outlet channel; The third direction is parallel to the thickness direction of the plate body.

12. The liquid flow battery plate according to claim 11, characterized in that: The accommodating cavity has a first side wall and a second side wall opposite to each other along the first direction, the first side wall is arranged close to the liquid inlet, and the second side wall is arranged close to the liquid outlet; Wherein, in the same liquid inlet channel, the ratio of the shortest distance between the first branch channel and the second side wall along the first direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 2 to 1; and / or In the same liquid outlet channel, the ratio of the shortest distance between the second branch channel and the first side wall along the first direction to the distance between the first main channel and the second main channel adjacent to each other along the second direction is 1 / 2 to 1.

13. The liquid flow battery plate according to claim 11, characterized in that: The porous medium is configured as carbon felt; and / or The plate body has a first surface and a second surface that are arranged back to back along the third direction; the liquid inlet, the liquid outlet, the liquid inlet channel and the liquid outlet channel are all opened on the first surface, and the opening is located on the second surface.

14. The liquid flow battery plate according to claim 11, characterized in that: The plate body includes a plate frame and a flow channel plate, the opening is arranged through the plate frame; the thickness of the flow channel plate is less than the thickness of the plate frame, and the flow channel plate is located in the opening of the plate frame to define the accommodating cavity; the liquid inlet and the liquid outlet are opened on the plate frame, and the liquid inlet flow channel and the liquid outlet flow channel are arranged through the flow channel plate.

15. A single battery, characterized in that: It includes a positive electrode assembly, an exchange membrane and a negative electrode assembly which are stacked in sequence; Wherein, the positive electrode assembly comprises a flow battery plate and a positive electrode as described in any one of claims 1 to 14, and the positive electrode is arranged on a surface of the plate body along a third direction close to the liquid inlet and the liquid outlet; and / or The negative electrode assembly comprises a flow battery plate and a negative electrode as claimed in any one of claims 1 to 14, wherein the negative electrode is disposed on a surface of the plate body on one side close to the liquid inlet and the liquid outlet along the third direction; The third direction is parallel to the thickness direction of the plate body.

16. A liquid flow battery stack, characterized in that: It comprises a plurality of sub-stacks, each of the sub-stacks comprising a plurality of single cells as claimed in claim 15 .

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