Electrode, plate frame and flow battery

Abstract

The invention relates to an electrode, a plate frame and a flow battery, a flow area is formed on the surface of the electrode, the electrode comprises two first side edges which are oppositely arranged and two second side edges which are oppositely arranged and are respectively connected between the two first side edges, a main liquid inlet and a main liquid outlet which are communicated with the liquid flow area are formed in the middles of the two second side edges respectively, an auxiliary liquid inlet and an auxiliary liquid outlet which are communicated with the liquid flow area are formed in the two sides of the two second side edges respectively, and at least one second side edge is constructed to be an outwards-protruding arc edge; the distance between the main liquid inlet and the main liquid outlet is larger than the distance between the auxiliary liquid inlet and the auxiliary liquid outlet. According to the technical scheme, the electrode provided by the invention can improve the distribution uniformity of the electrolyte, so that the concentration polarization is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of flow battery technology, specifically to an electrode, a plate and frame, and a flow battery. Background Technology

[0002] A vanadium redox flow battery consists of components such as a current collector, bipolar plates, electrodes, a separator, an inlet plate, and a clamping plate. Among these, the electrodes are the most crucial component, as the charging and discharging process involves redox reactions of the electrolyte on the electrode surface. During operation, the electrolyte distribution within the electrodes is uneven. The flow rate is high near the inlet / outlet, while slower further away due to the viscosity of the electrodes and electrolyte. This uneven flow rate leads to uneven electrolyte concentration distribution within the electrodes, resulting in significant concentration polarization and severely impacting battery performance. Summary of the Invention

[0003] The purpose of this disclosure is to provide an electrode, plate and frame, and flow cell, wherein the electrode can improve the uniformity of electrolyte distribution, thereby reducing concentration polarization.

[0004] To achieve the above objectives, this disclosure provides an electrode with a liquid flow region formed on its surface. The electrode includes two first sides arranged opposite to each other and two second sides arranged opposite to each other and respectively connected between the two first sides. The middle portions of the two second sides are respectively provided with a main liquid inlet and a main liquid outlet communicating with the liquid flow region. The two sides of the two second sides are respectively provided with a secondary liquid inlet and a secondary liquid outlet communicating with the liquid flow region. At least one of the second sides is constructed as a convex arc edge, so that the distance between the main liquid inlet and the main liquid outlet is greater than the distance between the secondary liquid inlet and the secondary liquid outlet.

[0005] Optionally, a main liquid flow channel is formed between the main liquid inlet and the main liquid outlet, and at least one of the first side sides is constructed as an inclined side, the inclined side having a first end near the main liquid inlet and a second end near the main liquid outlet, wherein the distance between the first end and the main liquid flow channel is greater than the distance between the second end and the main liquid flow channel.

[0006] Optionally, at least one of the second sides is provided with a capillary channel, which extends from one second side toward the other second side.

[0007] Optionally, each of the capillary channels on the second side includes a plurality of capillary channels, which are spaced apart along the extension direction of the second side.

[0008] Optionally, in two adjacent capillary channels, the length of the capillary channel closer to the first side is greater than the length of the capillary channel farther from the first side.

[0009] Optionally, the number of the multiple capillary channels gradually increases from the center of the second side toward both sides.

[0010] Optionally, the plurality of capillary channels are arranged symmetrically with respect to the center of the second side.

[0011] Optionally, capillary channels are provided on both second sides. Each capillary channel includes an inlet capillary channel and an outlet capillary channel. The inlet capillary channel is located on the second side having the main inlet, and the outlet capillary channel is located on the other second side having the main outlet. The inlet capillary channel and the outlet capillary channel are arranged alternately along a line perpendicular to the line connecting the main inlet and the main outlet.

[0012] Optionally, the central angle corresponding to the arc edge is 30° to 40°.

[0013] Based on the above technical solution, this disclosure also provides a plate frame, which is used to surround the outer periphery of the electrode. The plate frame is provided with a main liquid inlet, a main liquid outlet, a liquid inlet buffer, and a liquid outlet buffer. The liquid inlet buffer and the liquid outlet buffer are respectively attached to one of the two second sides of the electrode and extend along the length direction of the second side. The main liquid inlet is connected to the liquid flow area through the liquid inlet buffer, and the main liquid outlet is connected to the liquid flow area through the liquid outlet buffer. The connection between the main liquid inlet and the liquid inlet buffer is opposite to the connection between the liquid inlet buffer and the main liquid inlet, and the connection between the main liquid outlet and the liquid outlet buffer is opposite to the connection between the liquid outlet buffer and the main liquid outlet.

[0014] Optionally, the inlet buffer is provided with a plurality of inlet diverters, which are arranged at intervals along the extension direction of the inlet buffer; and / or, the outlet buffer is provided with a plurality of outlet diverters, which are arranged at intervals along the extension direction of the outlet buffer.

[0015] Optionally, the number of the plurality of inlet diverters gradually increases from the center of the inlet buffer towards both sides; and / or, the number of the plurality of outlet diverters gradually increases from the center of the outlet buffer towards both sides.

[0016] Optionally, the length of the inlet diverter gradually decreases from the middle of the inlet buffer towards both sides; and / or, the length of the outlet diverter gradually decreases from the middle of the outlet buffer towards both sides.

[0017] Optionally, the plate frame has multiple mounting cavities arranged side by side and adjacent mounting cavities are separated by an electrode partition. Each mounting cavity contains an electrode, and the main liquid inlet or main liquid outlet of two adjacent electrodes are located on different sides of the arrangement direction of the multiple mounting cavities.

[0018] Based on the above technical solutions, this disclosure also provides a flow battery, including the electrodes and the plate frame described above.

[0019] Through the above technical solution, in the electrode provided in this disclosure, by setting at least one second side to an outwardly convex arc shape, and placing the main inlet and main outlet in the middle of the two second sides respectively, while placing the auxiliary inlet and auxiliary outlet on both sides of the two second sides respectively, the distance between the main inlet and main outlet is increased, so that the distance between the main inlet and main outlet is greater than the distance between the auxiliary inlet and auxiliary outlet. Thus, even if the flow rate at the main inlet and main outlet is high, while the flow rate at the auxiliary inlet and auxiliary outlet is slow, the optimized electrode structure ensures that the distance between the main inlet and main outlet is greater than the distance between the auxiliary inlet and auxiliary outlet. The distance between the secondary outlets, that is, the flow path (i.e., the liquid flow path) between the main inlet and the main outlet, is greater than the flow path between the secondary inlet and the secondary outlet. Therefore, compared to the flow path between the secondary inlet and the secondary outlet with slower flow rates, the flow path between the main inlet and the main outlet with faster flow rates is longer. This can prolong the residence time of the electrolyte in the electrode in this flow path, reduce the concentration difference of the electrolyte in the flow path between the secondary inlet and the secondary outlet and the flow path between the main inlet and the main outlet, improve the uniformity of electrolyte concentration inside the electrode, reduce concentration polarization, and thus improve the performance of the flow battery.

[0020] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a schematic diagram of the assembly structure of a single electrode and a plate frame in an exemplary embodiment provided in this disclosure;

[0023] Figure 2 This is an exploded view of a single electrode and plate frame in an exemplary embodiment provided in this disclosure;

[0024] Figure 3This is a schematic diagram of the assembly structure of multiple electrodes and a plate frame in an exemplary embodiment provided in this disclosure;

[0025] Figure 4 This is a schematic diagram of the structure of the electrode in an exemplary embodiment provided in this disclosure;

[0026] Figure 5a This is the flow field model corresponding to the exemplary embodiments provided in this disclosure when a trapezoidal single electrode and plate frame are used;

[0027] Figure 5b This is the flow field model corresponding to the exemplary embodiments provided in this disclosure when a trapezoidal single electrode and plate frame are used;

[0028] Figure 6a This is a flow field cross-sectional velocity distribution cloud map (within the range of 0 to 0.08 m / s) corresponding to the exemplary embodiments provided in this disclosure when a trapezoidal single electrode and plate frame are used;

[0029] Figure 6b This is a flow field cross-sectional velocity distribution cloud map (within the range of 0 to 0.08 m / s) corresponding to the exemplary embodiments provided in this disclosure when a trapezoidal single electrode and plate frame are used;

[0030] Figure 7a This is a flow field pressure distribution cloud map corresponding to the exemplary embodiment provided in this disclosure when a trapezoidal single electrode and plate frame are used;

[0031] Figure 7b This is a flow field pressure distribution cloud map corresponding to the exemplary embodiment provided in this disclosure when a trapezoidal single electrode and plate frame are used.

[0032] Explanation of reference numerals in the attached figures

[0033] 1-Electrode; 11-Flow zone; 12-First side; 13-Second side; 131-Main inlet; 132-Main outlet; 133-Secondary inlet; 134-Secondary outlet; 135-Inlet capillary channel; 136-Outlet capillary channel; 2-Plate frame; 21-Main inlet; 22-Main outlet; 23-Inlet buffer zone; 231-Inlet distributor; 24-Outlet buffer zone; 241-Outlet distributor; 25-Mounting cavity; 26-Electrode partition. Detailed Implementation

[0034] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0035] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to "inner" and "outer" relative to the contour of the corresponding component itself. Furthermore, the terms "first," "second," etc., used in this disclosure are for distinguishing one element from another and do not have sequential or importance implications. Additionally, in the following description, when referring to the accompanying drawings, unless otherwise explained, the same reference numerals in different drawings denote the same or similar elements. The above definitions are for explanation and illustration only and should not be construed as limiting this disclosure.

[0036] To solve the above-mentioned technical problems, the positive and negative electrodes of the flow battery are designed as trapezoids, and an outlet and an inlet are respectively opened on the upper and lower bases of the trapezoid. In this way, under the same flow rate, the inlet velocity is small and the outlet velocity is large, which can overcome the defect of large concentration gradient caused by high electrolyte concentration at the inlet and low electrolyte concentration at the outlet. Therefore, the concentration polarization inside the battery can be reduced.

[0037] However, when using a trapezoidal electrode, since the inlet and outlet are located in the middle of the lower and upper sides of the trapezoid, respectively, the flow field simulation results show that the flow velocity at the inlet is significantly greater than that at the outlet. The flow velocity is fast in the areas near the inlet and outlet, while the flow velocity is slow in the areas on both sides of the inlet and outlet. In other words, in the trapezoidal electrode structure, the flow path corresponding to the middle area with a faster flow velocity is smaller than that corresponding to the two sides with a slower flow velocity. This can still easily lead to uneven distribution of reactant concentration, resulting in concentration polarization of the electrolyte inside the battery.

[0038] Therefore, this disclosure provides an electrode, with reference to Figures 1 to 4 As shown, a liquid flow region 11 is formed on the surface of the electrode 1. The electrode 1 includes two first sides 12 arranged opposite to each other and two second sides 13 arranged opposite to each other and respectively connected between the two first sides 12. The middle part of the two second sides 13 is provided with a main liquid inlet 131 and a main liquid outlet 132 communicating with the liquid flow region 11. The two sides of the two second sides 13 are provided with a secondary liquid inlet 133 and a secondary liquid outlet 134 communicating with the liquid flow region 11. At least one of the second sides 13 is constructed as an outwardly convex arc edge so that the distance between the main liquid inlet 131 and the main liquid outlet 132 is greater than the distance between the secondary liquid inlet 133 and the secondary liquid outlet 134.

[0039] Through the above technical solution, in the electrode 1 provided in this disclosure, by setting at least one second side 13 as an outwardly convex arc shape, and placing the main liquid inlet 131 and the main liquid outlet 132 respectively in the middle of the two second side 13, while placing the auxiliary liquid inlet 133 and the auxiliary liquid outlet 134 respectively on both sides of the two second side 13, the distance between the main liquid inlet 131 and the main liquid outlet 132 is increased, so that the distance between the main liquid inlet 131 and the main liquid outlet 132 is greater than the distance between the auxiliary liquid inlet 133 and the auxiliary liquid outlet 134. In this way, even if the flow rate of the main liquid inlet 131 and the main liquid outlet 132 is fast, while the flow rate of the auxiliary liquid inlet 133 and the auxiliary liquid outlet 134 is slow, the optimized electrode structure can still maintain a greater distance between the main liquid inlet 131 and the main liquid outlet 132. The distance between the secondary inlet 133 and the secondary outlet 134 is greater than that between the main inlet 131 and the main outlet 132. This means that the flow path (i.e., the liquid flow path) between the main inlet 131 and the main outlet 132 is greater than that between the secondary inlet 133 and the secondary outlet 134. Therefore, compared to the flow path between the secondary inlet 133 and the secondary outlet 134, which has a slower flow rate, the flow path between the main inlet 131 and the main outlet 132 has a longer flow path. This can prolong the residence time of the electrolyte in the electrode in this flow path, reduce the concentration difference of the electrolyte in the flow path between the secondary inlet 133 and the secondary outlet 134 and the flow path between the main inlet 131 and the main outlet 132, improve the uniformity of electrolyte concentration inside the electrode, reduce concentration polarization, and thus improve the performance of the flow battery.

[0040] In the exemplary embodiments provided in this disclosure, to ensure that the optimization of the electrode 1 structure can improve the uniformity of the electrolyte concentration inside the electrode 1, the central angle corresponding to the arc-shaped second side 13 can be set to 30° to 40°. Exemplarily, the central angle can be 30°, 32°, 34°, 36°, 38° or 40°, or any suitable angle within the range of 30° to 40°. The specific angle can be flexibly selected according to the actual situation, and this disclosure does not impose any restrictions on it.

[0041] In the exemplary embodiments provided in this disclosure, a main liquid flow channel can be formed between the main liquid inlet 131 and the main liquid outlet 132. Therefore, the two first sides 12 can have at least the following possible implementation methods:

[0042] In the first possible implementation, both first side edges 12 are constructed as straight edges parallel to the main fluid flow channel.

[0043] In the second possible implementation, one of the two first side edges 12 is constructed as a straight edge parallel to the main fluid flow channel, while the other is constructed as an inclined edge with a certain angle to the main fluid flow channel.

[0044] In the third possible implementation, refer to Figures 1 to 4 As shown, both first side edges 12 are constructed as inclined sides with a certain angle to the main liquid flow channel.

[0045] In the three implementation methods described above, the electrode 1 in the first implementation method has a near-rectangular structure, while the electrode 1 in the second and third implementation methods has a near-trapezoidal structure. When using a near-trapezoidal structure, the inclined side can have a first end and a second end. The first end is located near the main liquid inlet 131, and the second end is located near the main liquid outlet 132. Furthermore, the distance between the first end and the main liquid flow channel is greater than the distance between the second end and the main liquid flow channel. In other words, the liquid inlet is located on the lower base with a longer side length, and the liquid outlet is located on the upper base with a shorter side length. According to the law of conservation of mass, under the same flow rate, compared with the rectangular structure, the flow velocity at the outlet of the trapezoidal structure electrode is greater than the flow velocity at the inlet. Here, not only is the flow velocity at the main outlet 132 greater than the flow velocity at the main inlet 131, but the flow velocity at the secondary outlet 134 is also greater than the flow velocity at the secondary inlet 133. Therefore, the electrolyte located on both sides of the main liquid flow channel (that is, between the secondary inlet 133 and the secondary outlet 134) can pass through the electrode as quickly as possible, thereby increasing the supply rate of reactants in the electrolyte, reducing the existence of flow dead zones inside the electrode, reducing concentration polarization inside the flow battery, and improving the performance of the flow battery.

[0046] In the exemplary embodiments provided in this disclosure, reference is made to Figures 1 to 4 As shown, at least one second side 13 is also provided with a capillary channel, which extends from one second side 13 toward the other second side 13. In this way, by setting the capillary channel, a portion of the electrolyte can flow through the capillary channel to reduce the flow resistance of the electrolyte in the electrode and improve the flow uniformity of the electrolyte in the electrode.

[0047] In this disclosure, electrode 1 can be carbon cloth or carbon felt, while the capillary channel can be fabricated by etching or die cutting. The width of the capillary channel can be 1mm to 2mm. For example, the width of the capillary channel can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm, or any suitable size within the range of 1mm to 2mm. The specific size can be flexibly selected according to the actual situation, and this disclosure does not impose any limitations on it.

[0048] In order to improve the uniformity of electrolyte flow within the electrode, multiple capillary channels can be provided on each second side 13. These multiple capillary channels are arranged at intervals along the extension direction of the second side 13. By increasing the number of capillary channels, more electrolyte can pass through these capillary channels, thereby enhancing the effect of setting capillary channels on the uniformity of electrolyte flow within the electrode.

[0049] In the exemplary embodiments provided in this disclosure, reference is made to Figures 1 to 4 As shown, in two adjacent capillary channels, the length of the capillary channel closer to the first side 12 is greater than the length of the capillary channel farther from the first side 12. In this way, by gradually increasing the length of the capillary channel from the middle to both sides, more electrolyte can be guided to both sides of the electrode 1 through these capillary channels with longer channels, avoiding the electrolyte from concentrating in the middle region of the electrode 1. Therefore, the uniformity of electrolyte flow inside the electrode 1 can be improved.

[0050] In the exemplary embodiments provided in this disclosure, reference is made to Figures 1 to 4 As shown, the number of capillary channels can be arranged to gradually increase from the middle of the second side 13 toward both sides. In this way, by reasonably distributing the number of capillary channels, as much electrolyte as possible inside the electrode 1 can pass through the large number of distributed capillary channels and be located between the auxiliary inlet 133 and auxiliary outlet 134 on both sides, while a smaller amount of electrolyte passes through the small number of distributed capillary channels and is located between the main inlet 131 and main outlet 132 in the middle, thereby improving the uniformity of electrolyte flow inside the electrode.

[0051] In the exemplary embodiments provided in this disclosure, reference is made to Figures 1 to 4 As shown, in order to make the electrolyte as uniformly distributed as possible within the electrode, multiple capillary channels can be arranged symmetrically with respect to the center of the second side 13.

[0052] In the exemplary embodiments provided in this disclosure, reference is made to Figures 1 to 4 As shown, both second sides 13 are provided with capillary channels, including an inlet capillary channel 135 and an outlet capillary channel 136. The inlet capillary channel 135 is located on the second side 13 with a main liquid inlet 131, and the outlet capillary channel 136 is located on the other second side 13 with a main liquid outlet 132. The inlet capillary channel 135 and the outlet capillary channel 136 are arranged alternately along a line perpendicular to the line connecting the main liquid inlet 131 and the main liquid outlet 132. This further improves the uniformity of the distribution of capillary channels on the electrode body 1, so that the electrolyte can be uniformly distributed and flow in the electrode, whether in the width direction or the length direction of the electrode body 1.

[0053] Based on the above technical solution, and referring to Figures 1 to 4 As shown in the figure, this disclosure provides a plate frame 2, which is used to surround the outer periphery of the electrode 1. The plate frame 2 is provided with a main liquid inlet 21, a main liquid outlet 22, a liquid inlet buffer 23 and a liquid outlet buffer 24. The liquid inlet buffer 23 and the liquid outlet buffer 24 are respectively attached to one of the two second sides 12 of the electrode 1 and extend along the length direction of the second side 12. The main liquid inlet 21 is connected to the liquid flow area 11 through the liquid inlet buffer 23, and the main liquid outlet 22 is connected to the liquid flow area 11 through the liquid outlet buffer 24.

[0054] The connection between the main inlet 21 and the inlet buffer zone 23 is opposite to the connection between the inlet buffer zone 23 and the main inlet 131, and the connection between the main outlet 22 and the outlet buffer zone 24 is opposite to the connection between the outlet buffer zone 24 and the main outlet 132.

[0055] Through the above technical solution, the plate frame 2 provided in this disclosure, when applied to a flow battery, can be matched with the electrode 1. Specifically, on the one hand, the electrode 1 can be installed and fixed; on the other hand, the cooperation between the plate frame 2 and other structures and the electrode 1 allows the surface of the electrode body 1 to form a liquid flow zone 11 for electrolyte reaction and flow; furthermore, the arrangement of the plate frame 2 can also strengthen the structure of the electrode 1. The inlet buffer zone 23 and the outlet buffer zone 24 ensure that the electrolyte is within multiple uniformly distributed liquid flow channels before entering or exiting the liquid flow zone 11 on the surface of the electrode 1. This avoids the need for the electrolyte in the liquid flow zone 11 to flow in or out through an inlet or outlet concentrated in a certain area, thus improving the uniformity of electrolyte flow within the electrode 1.

[0056] In the above embodiments, the material of the plate frame 2 can be polyvinyl chloride (PVC), and its processing method can be machining methods such as milling and injection molding.

[0057] In the exemplary embodiments provided in this disclosure, in order to further improve the flow uniformity of the electrolyte within the electrode 1, flow dividers can be provided in the inlet buffer zone 23 and the outlet buffer zone 24, so that the inlet buffer zone 23 or the outlet buffer zone 24 is uniformly divided into multiple flow channels by these flow dividers, through which the electrolyte flows into or out of the liquid flow area 11 on the surface of the electrode body 1. The flow dividers can be implemented in at least three possible ways:

[0058] In a first possible implementation, a plurality of liquid inlet diverters 231 are provided on the liquid inlet buffer 23, and the plurality of liquid inlet diverters 231 are arranged at intervals along the extension direction of the liquid inlet buffer 23.

[0059] In the second possible implementation, a plurality of liquid outlet diverters 241 are provided on the liquid outlet buffer 24, and the plurality of liquid outlet diverters 241 are arranged at intervals along the extension direction of the liquid outlet buffer 24.

[0060] In the third possible implementation, refer to Figure 1 and Figure 3 As shown, a plurality of inlet diverters 231 are provided on the inlet buffer 23, and the plurality of inlet diverters 231 are arranged at intervals along the extension direction of the inlet buffer 23. A plurality of outlet diverters 241 are provided on the outlet buffer 24, and the plurality of outlet diverters 241 are arranged at intervals along the extension direction of the outlet buffer 24.

[0061] It should be noted that, in the above three implementation methods, when the second side 13 in electrode 1 is constructed as a straight edge, the "extension direction of the liquid inlet buffer 23" or the "extension direction of the liquid outlet buffer 24" refers to the length direction of the liquid inlet buffer 23 or the liquid outlet buffer 24 that matches and fits with the straight edge, which is the extension direction of the straight line. When the second side 13 is constructed as a convex arc edge, the "extension direction of the liquid inlet buffer 23" or the "extension direction of the liquid outlet buffer 24" refers to the length direction of the liquid inlet buffer 23 or the liquid outlet buffer 24 that matches and fits with the arc edge, which is the extension direction of the arc.

[0062] The width of each inlet diverter 231 or outlet diverter 241 can be set to 5mm to 8mm, and the length of each inlet diverter 231 or outlet diverter 241 can be set to 10mm to 40mm. For example, the width of each inlet diverter 231 or outlet diverter 241 can be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm, or any suitable size within the range of 5mm to 8mm; this disclosure does not impose any limitation on this. Similarly, the length of each inlet diverter 231 or outlet diverter 241 can be 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, or 40mm, or any suitable size within the range of 10mm to 40mm; this disclosure does not impose any limitation on this.

[0063] In the exemplary embodiments provided in this disclosure, the plurality of inlet diverters 231 and the plurality of outlet diverters 241 can be implemented in the following three possible ways:

[0064] In the first possible implementation, the number of multiple liquid inlet diverters 231 gradually increases from the center of the liquid inlet buffer 23 toward both sides.

[0065] In the second possible implementation, the number of multiple liquid outlet diverters 241 gradually increases from the center of the liquid outlet buffer zone 24 toward both sides.

[0066] In the third possible implementation, refer to Figure 1 and Figure 3 As shown, the number of multiple inlet diverters 231 gradually increases from the middle of the inlet buffer 23 toward both sides, and the number of multiple outlet diverters 241 gradually increases from the middle of the outlet buffer 24 toward both sides.

[0067] Among the three possible implementations mentioned above, by rationally distributing the number of inlet diverters 231 or outlet diverters 241, when the plate frame 2 is applied to a flow battery, the electrolyte can be dispersed as far as possible towards both sides of the line connecting the main inlet port 131 and the main outlet port 132 through the liquid flow channels formed by these inlet diverters 231 or outlet diverters 241. This can prevent the electrolyte from concentrating in the main liquid flow channel formed between the main inlet port 131 and the main outlet port 132, thereby improving the uniformity of electrolyte flow inside the electrode 1.

[0068] In the exemplary embodiments provided in this disclosure, the variation pattern of the length dimension of the inlet diverter 231 or the outlet diverter 241 can be implemented in the following three possible ways:

[0069] In the first possible implementation, the length of the inlet diverter 231 gradually decreases from the middle of the inlet buffer 23 toward both sides.

[0070] In the second possible implementation, the length of the liquid outlet splitter 241 gradually decreases from the middle of the liquid outlet buffer 24 toward both sides.

[0071] In the third possible implementation, refer to Figure 1 and Figure 3 As shown, the length of the inlet diverter 231 gradually decreases from the middle of the inlet buffer 23 toward both sides; and the length of the outlet diverter 241 gradually decreases from the middle of the outlet buffer 24 toward both sides.

[0072] In the three possible implementations described above, by controlling the length variation of the inlet diverter 231 or the outlet diverter 241, when the plate frame 2 is applied to a flow battery, the spacing between adjacent flow channels is adjusted by changing the length of these inlet diverters 231 or the outlet diverter 241. This results in a longer distance between adjacent flow channels in the middle and a shorter distance between adjacent flow channels on both sides. This reduces the concentration of electrolyte in the middle with a faster flow rate and increases the concentration of electrolyte on both sides with a slower flow rate, thereby improving the uniformity of electrolyte flow inside the electrode.

[0073] In the exemplary embodiments provided in this disclosure, reference is made to Figure 3 As shown, the plate frame 2 can be configured to have multiple mounting cavities 25 inside. The multiple mounting cavities 25 are arranged side by side and adjacent mounting cavities 25 are separated by electrode partitions 26. Each mounting cavity 25 contains an electrode 1. The main liquid inlet 131 or main liquid outlet 132 of adjacent electrodes 1 are located on different sides of the arrangement direction of the multiple mounting cavities 25. With this configuration, when multiple electrodes 1 are arranged in the plate frame 2 of this disclosure, by making the main liquid inlet 131 or main liquid outlet 132 of adjacent electrodes 1 located on different sides of the arrangement direction of the multiple mounting cavities 25 (i.e., staggered arrangement), the space occupied by these electrodes 1 in the plate frame 2 can be reduced, thereby improving the utilization rate of the plate frame 2.

[0074] Based on the above technical solutions, this disclosure also provides a flow battery, which includes the aforementioned electrode 1 and plate frame 2. The details regarding electrode 1 and plate frame 2 have already been described in detail above; therefore, to avoid repetition, they will not be repeated here.

[0075] In the flow battery provided in this disclosure, the flow battery can be divided into two types according to the number of electrodes 1: single-electrode flow battery and multi-electrode flow battery. Compared with single-electrode flow battery, multi-electrode flow battery has a larger battery power. Therefore, when the flow battery power is small, a single-electrode flow battery can be selected, while when the flow battery power is large, an appropriate number of multi-electrode flow batteries can be selected according to actual needs.

[0076] Among them, according to Figure 1 and Figure 3 The external structure of the middle electrode 1 and the plate frame 2 can further enhance the properties disclosed herein. Figure 1 and Figure 3The assembly structures of electrode 1 and plate frame 2 shown are respectively referred to as a trapezoidal single electrode and its plate frame structure and a trapezoidal multi-electrode and its plate frame structure. To illustrate the performance of the trapezoidal electrode and its plate frame structure of this disclosure, the following comparison will be made using a vanadium redox flow battery with a single electrode and its plate frame structure as an example, comparing the key flow field parameters obtained from experiments using the trapezoidal single electrode and its plate frame structure of this disclosure with those of a conventional trapezoidal single electrode and its plate frame structure:

[0077] Table 1

[0078]

[0079]

[0080] Depend on Figures 5a to 7a As shown in Table 1, the simulation results indicate that, with a constant inlet flow rate, the average velocity of the electrolyte is essentially the same in both the trapezoidal single electrode and its plate-and-frame structure and the trapezoidal single electrode and its plate-and-frame structure. However, the average variance of the electrolyte flow rate and the pressure drop are both smaller in the trapezoidal single electrode and its plate-and-frame structure, suggesting that the electrolyte flow rate distribution is more uniform and the pressure drop is smaller in the trapezoidal single electrode and its plate-and-frame structure. Furthermore, from... Figure 6a and Figure 6b It can be seen that the flow dead zone area (blue area) of the trapezoidal single electrode and its plate-and-frame structure is significantly lower than that of the trapezoidal single electrode and its plate-and-frame structure, and the electrolyte flow path with slow flow velocity on both sides of the trapezoidal single electrode and its plate-and-frame structure is significantly lower than that of the trapezoidal single electrode and its plate-and-frame structure.

[0081] Therefore, whether considering the uniformity of electrolyte flow or the structure of the electrode and plate frame, the advantages of the trapezoidal single electrode and its plate frame structure are significantly greater than those of the trapezoidal single electrode and its plate frame structure.

[0082] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0083] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0084] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. An electrode, characterized in that, The electrode surface forms a liquid flow region. The electrode includes two first sides arranged opposite to each other and two second sides arranged opposite to each other and respectively connected between the two first sides. The middle part of the two second sides is provided with a main liquid inlet and a main liquid outlet communicating with the liquid flow region. The two sides of the two second sides are provided with a secondary liquid inlet and a secondary liquid outlet communicating with the liquid flow region. In this configuration, at least one of the second side edges is constructed as an outwardly convex arc edge, such that the distance between the main liquid inlet and the main liquid outlet is greater than the distance between the auxiliary liquid inlet and the auxiliary liquid outlet.

2. The electrode according to claim 1, characterized in that, A main liquid flow channel is formed between the main liquid inlet and the main liquid outlet. At least one of the first side sides is constructed as an inclined side, which has a first end near the main liquid inlet and a second end near the main liquid outlet. The distance between the first end and the main liquid flow channel is greater than the distance between the second end and the main liquid flow channel.

3. The electrode according to claim 1, characterized in that, At least one of the second sides is provided with a capillary channel, which extends from one second side toward the other second side.

4. The electrode according to claim 3, characterized in that, The capillary channels on each of the second sides include a plurality of channels, which are spaced apart along the extension direction of the second side.

5. The electrode according to claim 4, characterized in that, In two adjacent capillary channels, the length of the capillary channel closer to the first side is greater than the length of the capillary channel farther from the first side.

6. The electrode according to claim 4, characterized in that, The number of the multiple capillary channels gradually increases from the center of the second side toward both sides.

7. The electrode according to claim 4, characterized in that, The multiple capillary channels are arranged symmetrically with respect to the middle of the second side.

8. The electrode according to claim 3, characterized in that, Both second sides are provided with capillary channels, each including an inlet capillary channel and an outlet capillary channel. The inlet capillary channel is located on the second side having the main inlet, and the outlet capillary channel is located on the other second side having the main outlet. The inlet capillary channel and the outlet capillary channel are arranged alternately along a line perpendicular to the line connecting the main inlet and the main outlet.

9. The electrode according to any one of claims 1-8, characterized in that, The central angle corresponding to the arc edge is 30° to 40°.

10. A plate frame, characterized in that, The plate frame is used to surround the outer periphery of the electrode according to any one of claims 1-9. The plate frame is provided with a main liquid inlet, a main liquid outlet, an inlet buffer, and an outlet buffer. The inlet buffer and the outlet buffer are respectively attached to one of the two second sides of the electrode and extend along the length direction of the second side. The main liquid inlet is connected to the liquid flow zone through the inlet buffer, and the main liquid outlet is connected to the liquid flow zone through the outlet buffer. The connection between the main inlet and the inlet buffer is opposite to the connection between the inlet buffer and the main inlet, and the connection between the main outlet and the outlet buffer is opposite to the connection between the outlet buffer and the main outlet.

11. The plate frame according to claim 10, characterized in that, The inlet buffer zone is provided with multiple inlet diverters, which are spaced apart along the extension direction of the inlet buffer zone; and / or, The liquid outlet buffer zone is provided with multiple liquid outlet diverters, which are arranged at intervals along the extension direction of the liquid outlet buffer zone.

12. The plate frame according to claim 11, characterized in that, The number of the multiple inlet diverters gradually increases from the center of the inlet buffer zone towards both sides; and / or, The number of the multiple liquid outlet diverters gradually increases from the center of the liquid outlet buffer zone toward both sides.

13. The plate frame according to claim 11, characterized in that, The length of the inlet diverter gradually decreases from the center of the inlet buffer zone towards both sides; and / or, The length of the liquid outlet diverter gradually decreases from the middle of the liquid outlet buffer zone toward both sides.

14. The plate frame according to any one of claims 10-13, characterized in that, The plate frame has multiple mounting cavities arranged side by side and separated by an electrode partition. Each mounting cavity contains an electrode, and the main liquid inlet or main liquid outlet of two adjacent electrodes are located on different sides of the arrangement direction of the multiple mounting cavities.

15. A flow battery, characterized in that, It includes the electrode according to any one of claims 1-9 and the plate frame according to any one of claims 10-14.

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