A flow guide plate for a low-concentration differential liquid flow battery

Abstract

The utility model belongs to the technical field of liquid flow battery, concretely relates to a low concentration difference liquid flow battery flow guide plate, including flow guide plate board body, be provided with at least two electrode frame on flow guide plate board body, along the width direction of flow guide plate board body up and down arrangement, be provided with liquid inlet and liquid outlet on flow guide plate board body, and the liquid inlet is connected with the liquid inlet end of electrode frame, and the liquid outlet is connected with the liquid outlet end of electrode frame, this low concentration difference liquid flow battery flow guide plate is arranged at least two electrode frames up and down arrangement along the width direction on flow guide plate board body, and the longitudinal flow path of traditional single electrode frame is split into a plurality of short paths, makes the vertical flow distance of electrolyte in electrode significantly shorten, simultaneously, the liquid inlet is connected with the liquid inlet end and the liquid outlet end of electrode frame directly with the liquid outlet, ensures the shortest of electrolyte transmission path, avoids the concentration gradient accumulation caused by long distance flow, thereby effectively reduces the negative influence of concentration difference polarization to battery efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of flow battery technology, specifically relating to a flow guide plate for a low concentration flow battery. Background Technology

[0002] Vanadium redox flow battery stacks, as highly efficient energy conversion devices for electrical and chemical energy, are widely used in large-scale energy storage and regulation. Their basic structure consists of multiple individual cells stacked and tightly bound together, forming a combination with multiple channels and a unified current output. During the charging and discharging process, the positive and negative electrolytes enter the stack through specific channels and are evenly distributed to all individual cells to participate in the charging and discharging reactions. After the reactions are complete, the electrolytes are collected together and flow out of the stack, achieving the storage and release of electrical energy.

[0003] Traditional flow guide plate structures use a single electrode frame, resulting in a long flow path for the electrolyte within the electrode and a significant difference in active material concentration between the inlet and outlet. Taking the positive electrode electrolyte as an example, its active material is tetravalent vanadium (VO₄²⁻). 2+ ) and pentavalent vanadium (VO2) + During the charging process, VO 2+ Oxidized to VO2 + Since the reaction rate is related to the current density, under constant current density and flow rate, the concentration difference per unit flow distance remains essentially constant. Therefore, the longer the flow distance, the greater the concentration difference between the inlet and outlet. When the electrolyte does not flow out of the electrode region of the reaction chamber, VO... 2+ If the electrolyte is depleted, side reactions (such as water electrolysis) will occur as it flows through the electrode region of the subsequent reaction chamber. This not only reduces battery efficiency but may also generate irreversible gases (such as hydrogen and oxygen), affecting system safety and cycle life. Therefore, effectively shortening the flow distance of the electrolyte in the electrodes and reducing the concentration difference between the inlet and outlet has become a key technical issue for improving the performance and reliability of flow batteries. Utility Model Content

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides a low-concentration flow battery guide plate, which solves the problem that the single electrode frame guide plate in existing vanadium redox flow battery stacks leads to a long flow path of electrolyte in the electrode and a large concentration difference of active materials at the inlet and outlet, resulting in reduced battery efficiency.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A flow guide plate for a low concentration flow battery is provided, comprising a flow guide plate body, on which at least two electrode frames are arranged vertically along the width direction of the flow guide plate body; the flow guide plate body is provided with an inlet and an outlet, the inlet being connected to the inlet end of the electrode frame, and the outlet being connected to the outlet end of the electrode frame.

[0006] The beneficial effects of adopting the above technical solution are as follows: This low concentration flow battery guide plate reduces the impact of side reactions on the overall efficiency of the battery stack by shortening the actual flow distance of the electrolyte in the electrodes, thereby improving the battery's charge and discharge performance. Specifically, by setting at least two electrode frames on the guide plate and arranging them vertically along the width direction, the longitudinal flow path of a single electrode frame is divided into multiple short paths, thereby shortening the vertical flow distance, reducing the concentration difference of the electrolyte within the electrode frames, and ensuring the uniform distribution of active materials in different regions of the electrodes, thus reducing the possibility of side reactions.

[0007] Furthermore, the liquid inlet includes a positive liquid inlet and a negative liquid inlet, and the liquid outlet includes a positive liquid outlet and a negative liquid outlet. The positive liquid inlet and the negative liquid inlet are located on the same side, and the positive liquid outlet and the negative liquid outlet are located on the same side. The positive liquid inlet is connected to the liquid inlet end of the electrode frame, and the negative liquid inlet is connected to the liquid outlet end of the electrode frame. The positive liquid inlet and the positive liquid outlet, as well as the negative liquid inlet and the negative liquid outlet, are arranged diagonally.

[0008] Furthermore, a reaction chamber is formed between the electrode frame and the guide plate. A liquid storage tank is provided on one long side of the reaction chamber. The liquid storage tank is connected to the reaction chamber through a permeation channel. A liquid inlet channel is provided on one side of the reaction chamber. One end of the liquid inlet channel is connected to the positive electrode inlet, and the other end of the liquid inlet channel is connected to the liquid storage tank. A liquid outlet channel is provided on the other side of the reaction chamber. One end of the liquid outlet channel is connected to the positive electrode outlet, and the other end of the liquid outlet channel is connected to the liquid storage tank.

[0009] The beneficial effects of adopting the above technical solution are as follows: By forming a reaction chamber between the electrode frame and the guide plate, and setting a storage tank and a permeation channel on one side of the long side of the reaction chamber, the pre-storage and uniform permeation of the electrolyte are realized. At the same time, the inlet channel connects the positive electrode inlet to the storage tank, so that the high-concentration electrolyte first enters the storage tank for buffering and then enters the reaction chamber through the permeation channel, avoiding local polarization caused by concentration shock. The outlet channel connects the reaction chamber to the positive electrode outlet, and together with the permeation effect of the storage tank, a dynamic concentration balance is formed, which further shortens the effective flow distance of the electrolyte in the electrode, thereby significantly reducing the concentration difference between the inlet and outlet and improving the uniformity of the battery reaction and the overall efficiency.

[0010] Furthermore, the inlet and outlet channels are respectively located on both sides of the long side of the electrode frame.

[0011] The beneficial effects of adopting the above technical solution are as follows: by setting the inlet and outlet channels on both sides of the long side of the electrode frame, the electrolyte can flow unidirectionally along the long side and quickly reach or leave the reaction zone. This avoids the problem of the flow path detour caused by the concentration of channels on the short side in the traditional structure. It also shortens the vertical flow distance of the electrolyte in the electrode frame and reduces the space for concentration difference accumulation, thereby further reducing the concentration difference of active materials at the inlet and outlet and improving the battery charging and discharging efficiency.

[0012] Furthermore, the number of inlet and outlet channels is one or more.

[0013] The beneficial effects of adopting the above technical solution are as follows: by setting the number of inlet and outlet channels to one or more, the number of channels can be flexibly adjusted according to the size of the electrode frame and the electrolyte flow rate requirements. This ensures uniform distribution of electrolyte and optimizes the distribution density of the flow path. The single-channel design is suitable for small-sized electrode frames to simplify the structure, while the multi-channel structure can further shorten the electrolyte flow distance in local areas and reduce the accumulation of concentration differences. This reduces manufacturing complexity and improves the adaptability and overall efficiency of different specifications of fuel cell stacks.

[0014] Furthermore, the number of electrode frames is two or more.

[0015] The beneficial effects of adopting the above technical solution are as follows: by setting two or more electrode frames, the longitudinal flow path of the traditional single electrode frame can be divided into multiple independent short paths. While keeping the total electrode area unchanged, the vertical flow distance of the electrolyte in each electrode frame is significantly shortened, effectively reducing the accumulation of concentration gradient caused by the excessively long flow path of the electrolyte. At the same time, the space utilization rate is optimized by arranging multiple electrode frames vertically, which reduces the concentration difference of active materials at the inlet and outlet while improving the overall battery efficiency and system adaptability.

[0016] In summary, the beneficial effects of the low concentration flow battery guide plate provided by this utility model are as follows: This low-concentration flow battery guide plate, by setting at least two electrode frames arranged vertically along the width of the plate, splits the traditional longitudinal flow path into multiple short paths. While maintaining the total electrode area, it significantly shortens the vertical flow distance of the electrolyte within the electrodes, reducing the accumulation of concentration gradients caused by excessively long flow paths. This reduces the inlet and outlet concentration difference by more than 50%, effectively suppressing the negative impact of concentration polarization at the end of charging on the stack efficiency. Furthermore, the parallel structure of the multiple electrode frames optimizes space utilization, avoiding installation and structural problems caused by an excessively wide guide plate, and achieving a comprehensive improvement in battery charge / discharge performance, energy conversion efficiency, and system adaptability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the electrolyte flow structure of this utility model; Figure 3 This is a top view of the present invention; Among them, 1. guide plate body; 2. electrode frame; 3. positive electrode inlet; 4. positive electrode outlet; 5. negative electrode inlet; 6. negative electrode outlet; 7. reaction chamber; 8. storage tank; 9. permeation channel; 10. inlet channel; 11. outlet channel; 12. long side; 13. short side. Detailed Implementation

[0018] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0019] like Figures 1-3 As shown, the low concentration flow battery guide plate provided by this utility model includes a guide plate body 1, on which at least two electrode frames 2 are arranged vertically along the width direction of the guide plate body 1. The guide plate body 1 is provided with an inlet and an outlet. The inlet is connected to the inlet end of the electrode frame 2, and the outlet is connected to the outlet end of the electrode frame 2. The outlet includes a positive electrode inlet 3 and a negative electrode inlet 5, and the outlet includes a positive electrode outlet 4 and a negative electrode outlet 6. The positive electrode inlet 3 and the negative electrode inlet 5 are arranged on the same side, and the positive electrode outlet 4 and the negative electrode outlet 6 are arranged on the same side. The positive electrode inlet 3 is connected to the inlet end of the electrode frame 2, and the negative electrode inlet 5 is connected to the outlet end of the electrode frame 2. The positive electrode inlet 3 and the positive electrode outlet 4, and the negative electrode inlet 5 and the negative electrode outlet 6 are arranged diagonally. By setting at least two electrode frames 2 on the guide plate 1 and arranging them vertically along the width direction, the guide plate 1 maintains a constant total electrode area, but can divide the longitudinal flow path of a single electrode frame 2 into multiple short paths. This not only reduces the lateral space occupied by the flow channel, but also further reduces the concentration gradient of the electrolyte within the electrode frame 2 by shortening the vertical flow distance, ensuring the uniform distribution of active materials in different areas of the electrode, thereby improving the stability of the battery reaction. The inlet is directly connected to the inlet end of the electrode frame 2, ensuring the shortest path for electrolyte transport from the inlet to the electrode reaction zone, avoiding additional diffusion or mixing of the electrolyte in the flow channel, and allowing high concentrations of active materials (such as V) to be transported more evenly. 4+The electrolyte can quickly reach the reaction zone, reducing concentration loss due to excessive flow distance and improving the reaction efficiency in the initial stage of the battery. The outlet is connected to the outlet end of electrode frame 2, allowing the low-concentration electrolyte (such as V) after the reaction to reach the reaction zone quickly. 5+ The electrode frame 2 can be quickly discharged, preventing the backflow or retention of low-concentration electrolyte in the flow channel and avoiding polarization caused by excessive concentration at the outlet. At the same time, by quickly discharging the products, a stable electrolyte environment is provided for the next charge and discharge reaction, thereby ensuring the continuous improvement of battery efficiency and the stability of long-term operation.

[0020] In this invention, the number of electrode frames 2 is two or more. By setting two or more electrode frames 2, the longitudinal flow path of a traditional single electrode frame 2 can be divided into multiple independent short paths. While keeping the total electrode area unchanged, the vertical flow distance of the electrolyte in each electrode frame 2 is significantly shortened, effectively reducing the accumulation of concentration gradient caused by excessively long flow paths. At the same time, the vertical arrangement of multiple electrode frames 2 optimizes space utilization, reducing the concentration difference of active materials at the inlet and outlet while improving the overall battery efficiency and system adaptability.

[0021] like Figure 1 and Figure 2 As shown, a reaction chamber 7 is formed between the electrode frame 2 and the guide plate 1. A liquid storage tank 8 is located on one side of the long side of the reaction chamber 7. The liquid storage tank 8 is connected to the reaction chamber 7 through a permeation channel 9. An inlet channel 10 is provided on one side of the reaction chamber 7. One end of the inlet channel 10 is connected to the positive electrode inlet 3, and the other end of the inlet channel 10 is connected to the liquid storage tank 8. An outlet channel 11 is provided on the other side of the reaction chamber 7. One end of the outlet channel 11 is connected to the positive electrode outlet 4, and the other end of the outlet channel 11 is connected to the liquid storage tank 8. A reaction chamber 7 is formed between the electrode frame 2 and the guide plate 1. A storage tank 8 and a permeation channel 9 are set on one side of the long side of the reaction chamber 7, which realizes the pre-storage and uniform permeation of the electrolyte. At the same time, the inlet channel 10 connects the positive electrode inlet 3 to the storage tank 8, so that the high-concentration electrolyte first enters the storage tank 8 for buffering and then enters the reaction chamber 7 through the permeation channel 9, avoiding local polarization caused by concentration shock. The outlet channel 11 connects the reaction chamber 7 to the positive electrode outlet 4, and together with the permeation effect of the storage tank 8, a dynamic concentration balance is formed, which further shortens the effective flow distance of the electrolyte in the electrode, thereby significantly reducing the concentration difference between the inlet and outlet and improving the uniformity of the battery reaction and the overall efficiency.

[0022] like Figure 2 and Figure 3As shown, the electrode frame 2 includes a long side 12 and a short side 13 that are perpendicular to each other. This allows the electrolyte to flow preferentially along the long side 12 within the guide plate 1 and along the short side 13 within the reaction chamber 7. This effectively shortens the flow distance of the electrolyte in the vertical direction (short side 13 direction) while keeping the total electrode area constant. This reduces the accumulation of concentration gradient caused by the excessively long flow path of the electrolyte. At the same time, the concentrated flow along the long side 12 direction optimizes the utilization rate of the flow channel space, further reduces the concentration difference of active materials at the inlet and outlet, and improves the uniformity of the battery reaction and the energy conversion efficiency.

[0023] like Figure 2 As shown, the inlet channel 10 and the outlet channel 11 are respectively disposed on both sides of the long side 12 of the electrode frame 2, and the number of inlet channels 10 and outlet channels 11 is one or more. By setting the number of inlet channels 10 and outlet channels 11 to one or more, the number of channels can be flexibly adjusted according to the size of the electrode frame 2 and the electrolyte flow rate requirements. This ensures uniform electrolyte distribution and optimizes the distribution density of the flow path. The single-channel design is suitable for small-sized electrode frames 2 to simplify the structure, while the multi-channel structure can further shorten the electrolyte flow distance in local areas and reduce the accumulation of concentration differences. This reduces manufacturing complexity and improves the adaptability and overall efficiency of different specifications of fuel cell stacks.

[0024] In summary, the low concentration flow battery guide plate provided by this utility model, by setting at least two electrode frames 2 arranged vertically along the width direction on the guide plate body 1, splits the longitudinal flow path of the traditional single electrode frame 2 into multiple short paths, which significantly shortens the vertical flow distance of the electrolyte in the electrode; at the same time, the inlet and outlet are directly connected to the inlet and outlet ends of the electrode frame 2, ensuring the shortest electrolyte transport path and avoiding the accumulation of concentration gradient caused by long-distance flow, thereby effectively reducing the negative impact of concentration polarization on battery efficiency.

Claims

1. A flow guide plate for a low concentration flow battery, characterized in that: Includes a guide plate body (1), on which at least two electrode frames (2) are provided, the electrode frames (2) being arranged vertically along the width direction of the guide plate body (1); the guide plate body (1) is provided with an inlet and an outlet, the inlet being connected to the inlet end of the electrode frame (2), and the outlet being connected to the outlet end of the electrode frame (2).

2. The low concentration flow battery guide plate according to claim 1, characterized in that: The liquid inlet includes a positive electrode liquid inlet (3) and a negative electrode liquid inlet (5), and the liquid outlet includes a positive electrode liquid outlet (4) and a negative electrode liquid outlet (6). The positive electrode liquid inlet (3) and the negative electrode liquid inlet (5) are arranged on the same side, and the positive electrode liquid outlet (4) and the negative electrode liquid outlet (6) are arranged on the same side. The positive electrode liquid inlet (3) and the positive electrode liquid outlet (4), and the negative electrode liquid inlet (5) and the negative electrode liquid outlet (6) are arranged diagonally.

3. The low concentration flow battery guide plate according to claim 1, characterized in that: A reaction chamber (7) is formed between the electrode frame (2) and the guide plate (1). A liquid storage tank (8) is provided on one side of the long side of the reaction chamber (7). The liquid storage tank (8) is connected to the reaction chamber (7) through a permeation channel (9). A liquid inlet channel (10) is provided on one side of the reaction chamber (7). One end of the liquid inlet channel (10) is connected to the positive electrode liquid inlet (3), and the other end of the liquid inlet channel (10) is connected to the liquid storage tank (8). A liquid outlet channel (11) is provided on the other side of the reaction chamber (7). One end of the liquid outlet channel (11) is connected to the positive electrode liquid outlet (4), and the other end of the liquid outlet channel (11) is connected to the liquid storage tank (8).

4. The low concentration flow battery guide plate according to claim 3, characterized in that: The inlet channel (10) and outlet channel (11) are respectively located on both sides of the long side (12) of the electrode frame (2).

5. The low concentration flow battery guide plate according to claim 4, characterized in that: The number of inlet channels (10) and outlet channels (11) is one or more.

6. The low concentration flow battery guide plate according to claim 1 or 3, characterized in that: The number of electrode frames (2) is two or more.

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