A circular structure reference cell for monitoring electrode potential

Abstract

The application relates to the technical field of a vanadium redox flow battery, in particular to a circular structure reference battery for monitoring electrode potential, which comprises an electrochemical unit and two circular units. The electrochemical unit comprises a proton exchange membrane and electrode assemblies symmetrically arranged on two sides of the proton exchange membrane; the two circular units are symmetrically arranged on the two sides of the proton exchange membrane, a closed electrode cavity is formed between the circular unit and the proton exchange membrane, the electrode assemblies are arranged in the electrode cavity, a plurality of liquid inlet hole groups uniformly distributed in the circumferential direction are arranged on the circular unit, the plurality of liquid inlet hole groups are communicated with the circumferential edge of the electrode cavity; a liquid outlet assembly is arranged on the circular unit, the liquid outlet assembly is communicated with the central area of the electrode cavity, one end of the liquid outlet assembly extends out of the circular unit, electrolyte enters from the circumferential edge area of the electrode cavity through the plurality of liquid inlet hole groups, flows radially to the central area of the electrode cavity, and then flows out from the liquid outlet assembly. The application has the effects of providing a uniform flow field and ensuring stable and reliable signals.

Description

Technical Field

[0001] This application relates to the technical field of vanadium redox flow batteries, and in particular to a circular reference battery for monitoring electrode potential. Background Technology

[0002] Currently, with the rapid development of renewable energy industries such as wind and solar power, large-scale energy storage technologies have become crucial. Vanadium redox flow batteries (VRFBs) are considered one of the most promising large-scale energy storage technologies due to their unique advantages, such as high intrinsic safety, long cycle life, and the ability to independently design rated power and energy storage capacity.

[0003] In the actual operation, maintenance, and research and development of vanadium redox flow battery stacks, it is necessary to monitor the electrode potentials of the positive and negative half-cells in real time in order to accurately grasp the internal state of the battery. The reference cell is a key component for realizing this function. In related technologies, for the convenience of design and manufacturing, the reference cell often directly adopts the rectangular structure of the main cell, and its electrolyte usually flows in from one side and flows out from the opposite side or diagonally.

[0004] However, in a rectangular flow field, the path length of the electrolyte flowing from the inlet to the outlet across different points on the electrode surface is not the same, which inevitably leads to uneven flow velocity distribution of the electrolyte within the electrode active region. In areas with slow flow velocity (such as "dead zones" in corners), reactants are not renewed in a timely manner; while in "dominant channels" with faster flow velocity, the electrolyte is washed away too quickly. At the electrochemical level, the difference in flow velocity directly leads to different renewal rates of electrolyte ions at different points on the electrode surface, resulting in an uneven electrolyte concentration distribution, i.e., the phenomenon of "local concentration polarization." Since the magnitude of the electrode potential is highly sensitive to the ion concentration at the electrode / electrolyte interface, this uneven concentration distribution directly causes drastic fluctuations, long-term drift, and even signal distortion in the potential signal measured by the reference electrode, seriously affecting the accuracy of battery state estimation and impacting the control precision and operational safety of the entire battery management system.

[0005] Therefore, there is an urgent need to develop a dedicated reference battery structure that can provide a uniform flow field and ensure stable and reliable signals. Summary of the Invention

[0006] To provide a uniform flow field and ensure stable and reliable signals, this application provides a circular reference cell for monitoring electrode potential.

[0007] This application provides a circular reference battery for monitoring electrode potential, employing the following technical solution:

[0008] A circular reference cell for monitoring electrode potential includes:

[0009] An electrochemical unit includes a proton exchange membrane and electrode assemblies symmetrically arranged on both sides of the proton exchange membrane;

[0010] Two circular units are symmetrically arranged on both sides of the proton exchange membrane. A closed electrode chamber is formed between the circular units and the proton exchange membrane. The electrode assembly is disposed in the electrode chamber. The circular units are provided with a plurality of liquid inlet holes evenly distributed along the circumference. The plurality of liquid inlet holes are connected to the periphery of the electrode chamber.

[0011] The circular unit is provided with a liquid outlet assembly. One end of the liquid outlet assembly is connected to the central region of the electrode chamber, and the other end of the liquid outlet assembly extends out of the circular unit. The electrolyte can enter from the peripheral region of the electrode chamber through multiple liquid inlet holes, flow radially towards the central region of the electrode chamber, and then flow out from the liquid outlet assembly.

[0012] By adopting the above technical solution, the circular unit and the proton exchange membrane form a closed electrode chamber. The inlet holes evenly distributed circumferentially on the circular unit are connected to the periphery of the electrode chamber, while the outlet assembly is connected to the central region of the electrode chamber. This allows the electrolyte to enter from the periphery of the electrode chamber through the inlet holes, flow radially towards the center, and then exit from the outlet assembly. This circular symmetrical flow field structure with multiple inlets at the periphery and outlet at the center ensures uniform distribution of the electrolyte within the electrode chamber region where the electrode assembly is located, effectively suppressing local concentration polarization, thereby obtaining a stable and accurate potential signal and greatly improving the reliability of the stack monitoring.

[0013] Optionally, the circular unit includes an end panel, an insulating plate, and a support frame assembly. The end panel, the insulating plate, and the support frame assembly are stacked coaxially along the liquid outlet assembly. An inlet pipe is provided at the center of the end panel. The inlet pipe is sleeved outside the liquid outlet assembly and spaced apart from the liquid outlet assembly.

[0014] The liquid inlet group includes a first liquid inlet, and a plurality of the first liquid inlets are evenly distributed circumferentially on the insulating plate. A first drainage groove is formed on the insulating plate, and the first drainage groove is connected to the liquid inlet pipe and the plurality of the first liquid inlets respectively. The support frame group is connected to the proton exchange membrane, and the electrode chamber is formed between the support frame group and the proton exchange membrane. The support frame group is used to support and position the electrode assembly.

[0015] By adopting the above technical solution, an inlet pipe is set at the center of the end panel, sleeved outside the liquid outlet assembly and spaced apart, making the inlet and outlet channels independent and facilitating the delivery of electrolyte. Multiple first inlet holes evenly distributed circumferentially on the insulating plate are connected to the inlet pipe through first drainage grooves, enabling the electrolyte flowing in from the inlet pipe to be evenly distributed to each first inlet hole. The support frame assembly connects to the proton exchange membrane to form an electrode chamber and supports and positions the electrode assembly, ensuring the stable position of the electrode assembly within the electrode chamber. This allows the electrolyte to enter the electrode chamber evenly from the periphery, forming a multi-point inlet pattern, ensuring uniform distribution of electrolyte in the electrode area, effectively suppressing local concentration polarization, and thus obtaining a stable and accurate potential signal. This greatly improves the reliability of the stack monitoring, while also simplifying the battery structure, reducing overall processing difficulty and manufacturing costs, and improving production feasibility and consistency.

[0016] Optionally, the support frame assembly includes a support plate frame and an electrode frame arranged sequentially. The support plate frame and the electrode frame are coaxially arranged with the liquid outlet assembly. The support plate frame is connected to the insulating plate. The electrode frame is connected to the proton exchange membrane and surrounds the electrode chamber. The electrode assembly includes a bipolar plate and a working electrode. The bipolar plate and the working electrode are coaxially arranged in the electrode chamber. The support plate frame and the electrode frame sandwich the bipolar plate. The working electrode is disposed between the bipolar plate and the proton exchange membrane.

[0017] By adopting the above technical solution, the support frame is connected to the insulating plate, and the electrode frame is connected to the proton exchange membrane and arranged around the electrode chamber. The support frame and electrode frame sandwich the bipolar plate, and the working electrode is positioned between the bipolar plate and the proton exchange membrane. This ensures stable support and precise positioning of the electrode assembly within the electrode chamber. Stable support and positioning help the electrolyte to distribute evenly in the electrode area, thus ensuring the uniformity of the working electrode reaction. A uniform electrode reaction effectively reduces local concentration polarization, making the potential signal more stable and accurate, thereby improving the reliability of stack monitoring.

[0018] Optionally, the liquid inlet group includes a second liquid inlet, and a plurality of second liquid inlets are evenly distributed along the circumference of the support plate frame. The second liquid inlets correspond one-to-one with the first liquid inlets and are connected. A plurality of second drainage grooves are provided on the side of the electrode frame near the support plate frame. The plurality of second drainage grooves are evenly distributed along the circumference of the electrode frame. The second liquid inlets are connected to the second drainage grooves.

[0019] By adopting the above technical solution, multiple second liquid inlet holes are evenly distributed along the circumference of the support plate frame and are connected to the first liquid inlet holes one by one, allowing the electrolyte to flow smoothly from the first liquid inlet holes into the second liquid inlet holes. Multiple second drainage channels are evenly distributed circumferentially on the side of the electrode frame near the support plate frame, and the second liquid inlet holes are connected to the second drainage channels. This allows the electrolyte flowing in from the second liquid inlet holes to be evenly dispersed around the electrode frame through the second drainage channels, ensuring that the electrolyte can uniformly enter the electrode chamber from the periphery of the electrode frame. This achieves uniform distribution of the electrolyte in the electrode chamber, avoids local concentration polarization, and thus obtains a stable and accurate potential signal, improving the reliability of the stack monitoring.

[0020] Optionally, the liquid inlet group includes a third liquid inlet, which is evenly distributed along the circumference of the electrode frame. The third liquid inlet corresponds to and is connected to the second liquid inlet. The electrode frame is provided with a plurality of arc-shaped grooves evenly distributed along the circumference. The arc-shaped grooves are arranged in a one-to-one correspondence with the third liquid inlet. The third liquid inlet is connected to a plurality of the second drainage grooves through the arc-shaped grooves.

[0021] By adopting the above technical solution, the third liquid inlet is evenly distributed along the circumference of the electrode frame and corresponds one-to-one with the second liquid inlet, allowing the electrolyte flowing in from the second liquid inlet to smoothly enter the third liquid inlet. Arc-shaped grooves corresponding one-to-one with the third liquid inlet are provided on the electrode frame, and the third liquid inlet is connected to multiple second guide grooves through these arc-shaped grooves. This allows the electrolyte to be more evenly distributed to each of the second guide grooves, enabling the electrolyte to enter the working electrode more evenly from the periphery. This further ensures the uniform distribution of the electrolyte in the electrode chamber, reduces local concentration polarization, helps obtain stable and accurate potential signals, and improves the reliability of stack monitoring.

[0022] Optionally, the bipolar plate is provided with tabs on its periphery, and the support plate frame is provided with a slot, the tabs are inserted into the slot and extend to the outside of the support plate frame.

[0023] By adopting the above technical solution, tabs are provided around the periphery of the bipolar plate, and the tabs are inserted into the slots of the support plate frame and extend to the outside. This facilitates the conduction of the current collected by the bipolar plate to the external circuit during the charging and discharging process of the battery, thereby achieving effective current output and ensuring the normal charging and discharging function of the battery.

[0024] Optionally, the liquid outlet assembly includes a liquid outlet pipe and a flow guide frame. The liquid outlet pipe is coaxially inserted inside the liquid inlet pipe and spaced apart from the liquid inlet pipe. The flow guide frame is disposed in the electrode chamber and located in the central region of the electrode chamber. The flow guide frame is connected to the liquid outlet pipe and is used to collect the radially flowing electrolyte and guide it into the liquid outlet pipe.

[0025] By adopting the above technical solution, the outlet pipe is coaxially inserted inside the inlet pipe and spaced apart from it, forming independent inlet and outlet channels to ensure that the electrolyte flow does not interfere with each other. The guide plate frame is located in the central area of ​​the electrode chamber and is connected to the outlet pipe. It can converge the electrolyte flowing radially from the periphery of the electrode chamber to the central area, so that the radially flowing electrolyte can be orderly guided into the outlet pipe. This realizes the flow pattern of electrolyte entering from the periphery of the electrode chamber and flowing out from the center, thereby ensuring that the electrolyte is evenly distributed in the electrode chamber, eliminating local concentration polarization, obtaining a stable and accurate potential signal, and improving the reliability of stack monitoring.

[0026] Optionally, the outlet tube has a receiving hole in its inner wall. The receiving hole is closed and a diagnostic component is installed inside the receiving hole. One end of the diagnostic component extends into the electrode chamber. The diagnostic component is used to monitor multi-physics parameters.

[0027] By adopting the above technical solution, a closed receiving hole is opened inside the wall of the outlet pipe, and a diagnostic component is installed. One end of the diagnostic component extends into the electrode chamber, allowing direct contact with the environment within the electrode chamber. This enables real-time monitoring of the physical field parameters within the electrode chamber, providing accurate data support for battery status assessment and control, and helping to improve the stability and safety of battery operation. Simultaneously, the closed design of the receiving hole avoids interference with the inlet and outlet channels, ensuring normal electrolyte circulation.

[0028] Optionally, the diagnostic component includes a reference electrode wire and a microporous ceramic plug. The reference electrode wire is disposed in the receiving hole, and the microporous ceramic plug is disposed at one end of the receiving hole near the electrode chamber and connected to the reference electrode wire. The microporous ceramic plug connects the reference electrode wire and the electrolyte to achieve ion exchange.

[0029] By adopting the above technical solution, the reference electrode wire is placed in the receiving hole in the wall of the outlet tube. The end of the receiving hole near the electrode chamber is sealed with a microporous ceramic plug. The microporous ceramic plug connects the reference electrode wire and the electrolyte, allowing ion exchange and preventing macroscopic liquid flow. This allows the reference electrode wire to "sense" the potential of the electrolyte in the external electrode chamber, thereby enabling real-time, in-situ measurement of the potential of the electrolyte in the electrode chamber and realizing the monitoring of the electrode potential.

[0030] Optionally, the diagnostic component includes a temperature sensor disposed within the receiving hole, the temperature sensor's temperature-sensing probe extending to the central region of the electrode chamber.

[0031] By adopting the above technical solution, a receiving hole is opened in the wall of the liquid outlet pipe and a temperature sensor is installed. The temperature sensing probe extends to the center area of ​​the electrode chamber, which can measure the electrolyte temperature in the core area in real time. Combined with the potential monitoring signal, the potential measurement value is compensated in real time using the Nernst equation and the measured temperature to eliminate the error caused by temperature drift and obtain a more accurate electrochemical state. At the same time, abnormal fluctuations in the core temperature can provide early warning of short circuit risk or poor heat dissipation inside the battery.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. The circular symmetrical structure and the flow field design with multiple liquid inlets around the perimeter and liquid outlet at the center ensure that the electrolyte is evenly distributed in the electrode chamber, eliminate local concentration polarization, obtain a stable and accurate potential signal, and improve the reliability of stack monitoring.

[0034] 2. The core flow-guiding function is integrated into the insulating plate and electrode frame. The end plate structure is simple, which reduces manufacturing difficulty and cost, and improves production efficiency and consistency.

[0035] 3. The diagnostic components enable real-time monitoring of the physical field parameters within the electrode chamber, providing accurate data support for battery status assessment and control, and helping to improve the stability and safety of battery operation. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of a circular reference battery for monitoring electrode potential in Embodiment 1 of this application.

[0037] Figure 2 This is a cross-sectional view of a circular reference cell used for monitoring electrode potential in Embodiment 1 of this application.

[0038] Figure 3 This is an exploded structural diagram of a circular reference battery used for monitoring electrode potential, as described in Embodiment 1 of this application.

[0039] Figure 4 This is a schematic diagram of the structure of the insulating plate in Embodiment 1 of this application.

[0040] Figure 5 This is a schematic diagram of the electrode frame in Embodiment 1 of this application.

[0041] Figure 6 This is a cross-sectional view of a circular reference cell used for monitoring electrode potential in Embodiment 2 of this application.

[0042] Figure 7 yes Figure 6 A magnified view of a portion of point A in the middle.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Electrochemical unit; 11. Proton exchange membrane; 12. Electrode assembly; 121. Bipolar plate; 1211. Tab; 122. Working electrode; 2. Circular unit; 21. Liquid inlet group; 211. First liquid inlet; 212. Second liquid inlet; 213. Third liquid inlet; 22. Liquid outlet assembly; 221. Liquid outlet pipe; 2211. Receiving hole; 222. Drainage plate frame; 2221. Third drainage groove; 23. 1. End panel; 231. Through hole; 232. Liquid inlet pipe; 24. Insulating plate; 241. Protruding tube; 242. First drainage groove; 25. Support frame assembly; 251. Support plate frame; 2511. Slot; 252. Electrode frame; 2521. Arc groove; 2522. Second drainage groove; 26. Diagnostic component; 261. Reference electrode wire; 262. Temperature sensor; 263. Microporous ceramic plug; 3. Electrode chamber. Detailed Implementation

[0045] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0046] This application discloses a circular reference battery for monitoring electrode potential.

[0047] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] Example 1: Refer to Figure 1 and Figure 2 A circular reference cell for monitoring electrode potential includes an electrochemical unit 1 and two circular units 2 symmetrically arranged on both sides of the electrochemical unit 1, with a closed electrode chamber 3 formed between the circular units 2 and the electrochemical unit 1.

[0049] Reference Figure 2 and Figure 3 The circular unit 2 has multiple circumferentially distributed liquid inlet holes 21, which are connected to the periphery of the electrode chamber 3. The circular unit 2 is provided with a liquid outlet assembly 22, one end of which is connected to the central region of the electrode chamber 3. This allows the electrolyte to enter from the periphery of the electrode chamber 3, flow radially toward the center, and then flow out. This achieves a uniform distribution of the electrolyte in the electrode chamber, ensuring a stable and accurate potential signal and solving the problem of uneven flow field in traditional rectangular structures.

[0050] Reference Figure 3 The electrochemical unit 1 includes a proton exchange membrane 11 and electrode assemblies 12 symmetrically arranged on both sides of the proton exchange membrane 11. The proton exchange membrane 11 is made of a material with good proton conductivity and chemical stability, such as a perfluorosulfonic acid membrane, and is circular in shape to fit the overall circular structure of the reference cell.

[0051] The electrode assembly 12 includes a bipolar plate 121 and a working electrode 122. The bipolar plate 121 is made of a material with good electrical conductivity, such as a graphite plate, and has a relatively flat surface to facilitate current conduction. The working electrode 122 is made of a material with a large specific surface area, such as carbon felt, which provides more reactive sites.

[0052] Reference Figure 2 and Figure 3 The bipolar plate 121 and the working electrode 122 are coaxially arranged in the electrode chamber 3. The working electrode 122 is disposed between the bipolar plate 121 and the proton exchange membrane 11, and the bipolar plate 121, the working electrode 122 and the proton exchange membrane 11 are in close contact to ensure good electrical contact and smooth flow of electrolyte.

[0053] The circular unit 2 includes coaxially stacked end panels 23, insulating plates 24, and support frame 25. The end panels 23 serve as mechanical supports and are made of high-strength materials such as plastic or metal. A through hole 231 is provided in the center of the end panels 23.

[0054] In this embodiment, a protruding tube 241 is integrally formed at the center of the insulating plate 24. The protruding tube 241 passes through the through hole 231, and an inlet tube 232 is fixedly connected to the end panel 23. The inlet tube 232 is sleeved on the protruding tube 241 and communicates with the protruding tube 241. The inlet tube 232 is made of corrosion-resistant plastic or metal to ensure that the electrolyte can pass through smoothly.

[0055] Reference Figure 3 and Figure 4 The insulating plate 24 is made of plastic with good insulation properties, and a first drainage groove 242 is formed on the insulating plate 24. A cover plate can be installed on the insulating plate 24 to close the first drainage groove 242, and the cover plate and the insulating plate 24 can be connected by sealant or buckle to ensure the sealing of the flow channel.

[0056] In this embodiment, four sets of liquid inlet holes 21 are provided, and each set includes a first liquid inlet hole 211, a second liquid inlet hole 212, and a third liquid inlet hole 213. The four first liquid inlet holes 211 are evenly distributed circumferentially on the insulating plate 24. The first drainage groove 242 is connected to the liquid inlet pipe 232 and the four first liquid inlet holes 211, respectively, so that after the electrolyte enters from the liquid inlet pipe 232, it can be evenly distributed to each of the first liquid inlet holes 211 through the first drainage groove 242.

[0057] Reference Figure 3 The support frame assembly 25 includes a stacked support plate frame 251 and an electrode frame 252, both of which are coaxially arranged with the insulating plate 24. The support plate frame 251 is used to support and position the bipolar plate 121. The support plate frame 251 is made of plastic or metal material with a certain strength. Four second liquid inlet holes 212 are evenly distributed circumferentially on the support plate frame 251 to ensure that the electrolyte can smoothly enter the edge of the working electrode 122.

[0058] Reference Figure 2 and Figure 3 The support frame 251 is positioned close to the insulating plate 24, and the first liquid inlet hole 211 and the second liquid inlet hole 212 correspond to each other and are connected to ensure that the electrolyte can flow smoothly from the insulating plate 24 into the support frame 251. The electrode frame 252 is made of insulating material, and the electrode frame 252 is connected to the proton exchange membrane 11 and surrounds the electrode chamber 3.

[0059] The bipolar plate 121 is sandwiched between the support frame 251 and the electrode frame 252, and tabs 1211 are provided on the periphery of the bipolar plate 121. A slot 2511 is provided on the support frame 251, and the tabs 1211 are inserted into the slot 2511 and extend to the outside of the support frame 251. In this embodiment, the tabs 1211 are made of a metal material, such as copper sheet, and their function is to collect the current generated during battery charging and discharging and conduct it to the external circuit.

[0060] Reference Figure 3 and Figure 5 Four third liquid inlet holes 213 are evenly distributed circumferentially on the electrode frame 252, and the third liquid inlet holes 213 correspond one-to-one with and are connected to the second liquid inlet holes 212. The electrode frame 252 is provided with a plurality of arc-shaped grooves 2521 evenly distributed circumferentially, and the arc-shaped grooves 2521 are set one-to-one with the third liquid inlet holes 213. On the side of the electrode frame 252 near the support plate frame 251, a plurality of second drainage grooves 2522 are opened, and the plurality of second drainage grooves 2522 are evenly distributed circumferentially on the electrode frame 252. The third liquid inlet holes 213 are connected to the plurality of second drainage grooves 2522 through the arc-shaped grooves 2521, thereby enabling the electrolyte to be more evenly distributed in the electrode frame 252 and enabling the electrolyte to flow evenly to the working electrode 122 through the second drainage grooves 2522.

[0061] Reference Figure 3 The liquid outlet assembly 22 includes a liquid outlet pipe 221 and a flow guide plate frame 222. One end of the liquid outlet pipe 221 is coaxially inserted into the liquid inlet pipe 232, and the circumferential outer wall of the liquid outlet pipe 221 and the circumferential inner wall of the liquid inlet pipe 232 are spaced apart to form an independent liquid inlet channel.

[0062] Reference Figure 2 and Figure 3 The end of the outlet pipe 221 away from the inlet pipe 232 passes sequentially through the end panel 23, the insulating plate 24, and the support frame 251 and extends into the electrode chamber 3. The drainage plate frame 222 is disposed in the electrode chamber 3 and located in the central region of the electrode chamber 3. The drainage plate frame 222 is coaxially arranged with the outlet pipe 221 and is connected to the outlet pipe 221.

[0063] Multiple third diversion channels 2221 are provided at one end of the diversion plate frame 222 near the outlet pipe 221. The third diversion channels 2221 are evenly distributed along the circumference of the diversion plate frame 222, and the surface of the diversion plate frame 222 has a certain inclination so as to gather the radially flowing electrolyte and guide it into the outlet pipe 221.

[0064] The implementation principle of a circular reference battery for monitoring electrode potential according to an embodiment of this application is as follows: Taking one half-cell as an example, under the pressure of a pump, electrolyte flows in from the inlet pipe 232 and enters the first drainage groove 242 of the insulating plate 24. Through the first drainage groove 242, the electrolyte is evenly distributed to the four circumferentially distributed first inlet holes 211. Subsequently, the electrolyte sequentially enters the arc-shaped groove 2521 through the second inlet hole 212 and the third inlet hole 213, and then enters the second drainage groove 2522 through the arc-shaped groove 2521. This allows the electrolyte to enter the electrode chamber 3 from multiple points around the working electrode 122 and flow radially from the periphery of the electrode chamber 3 towards the center.

[0065] During the flow process, the electrolyte comes into full contact with the active material, and a stable electrode potential is established at the interface near the proton exchange membrane 11. Finally, the electrolyte after reaction / monitoring converges in the central region of the working electrode 122, is collected by the guide plate frame 222 and introduced into the outlet pipe 221, and finally discharged from the outlet pipe 221. This radial flow field design of "multiple points of liquid inlet around the periphery and central convergence of liquid outlet" ensures a high degree of uniformity of the flow field, thereby ensuring the stability and accuracy of the potential signal.

[0066] Example 2: Refer to Figure 6 and Figure 7 The difference between this embodiment and embodiment 1 is that a diagnostic component 26 is integrated on the liquid outlet tube 221.

[0067] The outlet pipe 221 has a receiving hole 2211 inside its wall, and the receiving hole 2211 is closed. In this embodiment, there are two receiving holes 2211, and the two receiving holes 2211 are isolated from each other.

[0068] The diagnostic component 26 includes a reference electrode wire 261 and a temperature sensor 262. The reference electrode wire 261 is disposed within a receiving hole 2211, and one end of the reference electrode wire 261 is connected to a microporous ceramic plug 263. The microporous ceramic plug 263 is located at the end of the receiving hole 2211 near the electrode chamber 3, and the microporous ceramic plug 263 connects the reference electrode wire 261 and the electrolyte to achieve ion exchange.

[0069] In this embodiment, the reference electrode wire 261 is an Ag / AgCl (silver chloride) electrode wire, and the microporous ceramic plug 263 can be made of materials such as high-silica glass, allowing ion exchange so that the internal reference electrode wire 261 can "sense" the potential of the electrolyte in the external fluid channel, but prevents macroscopic liquid flow. In other embodiments, the reference electrode wire 261 can also be made of titanium wire coated with noble metals.

[0070] The end of the reference electrode wire 261 away from the microporous ceramic plug 263 passes through the end of the outlet pipe 221 away from the electrode chamber 3, and is connected to an external potential measuring device through a sealed connector, so as to measure the potential of the electrolyte in the electrode chamber 3 in real time and in situ.

[0071] Temperature sensor 262 is disposed in another receiving hole 2211, and the temperature sensing probe of temperature sensor 262 extends to the central region of electrode chamber 3, thereby enabling real-time measurement of electrolyte temperature in the core region.

[0072] The implementation principle of Example 2 is as follows: When the electrolyte flows within the electrode chamber 3, the built-in reference electrode wire 261 achieves ion bonding with the flowing electrolyte through the microporous ceramic plug 263, thereby measuring the potential of the electrolyte in the electrode chamber 3 in real time and in situ. Simultaneously, the temperature sensor 262 measures the electrolyte temperature in the core region in real time. After receiving both the potential and temperature signals, the external control system can use the Nernst equation and the measured temperature value to compensate for the measured potential signal in real time, thus eliminating the influence of temperature fluctuations on the potential measurement and obtaining more accurate battery electrochemical state information. Furthermore, abnormal fluctuations in the core temperature (such as rapid increases) can serve as an early warning signal for micro-short circuits or poor heat dissipation within the battery, thereby improving the battery's operational safety.

[0073] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A circular reference battery for monitoring electrode potential, characterized in that, include: The electrochemical unit (1) includes a proton exchange membrane (11) and electrode assemblies (12) symmetrically arranged on both sides of the proton exchange membrane (11). Two circular units (2) are symmetrically arranged on both sides of the proton exchange membrane (11). A closed electrode chamber (3) is formed between the circular units (2) and the proton exchange membrane (11). The electrode assembly (12) is disposed in the electrode chamber (3). The circular unit (2) is provided with a plurality of circumferentially distributed liquid inlet hole groups (21), which are connected to the periphery of the electrode chamber (3). The circular unit (2) is provided with a liquid outlet assembly (22). The electrolyte can enter from the periphery of the electrode chamber (3) through the plurality of liquid inlet hole groups (21), flow radially toward the center of the electrode chamber (3), and then flow out from the liquid outlet assembly (22). The circular unit (2) includes an end panel (23), an insulating plate (24), and a support frame assembly (25). The end panel (23), the insulating plate (24), and the support frame assembly (25) are stacked coaxially along the liquid outlet assembly (22). An inlet pipe (232) is provided at the center of the end panel (23). The inlet pipe (232) is sleeved on the outside of the liquid outlet assembly (22) and spaced apart from the liquid outlet assembly (22). The liquid inlet group (21) includes a first liquid inlet (211), and a plurality of first liquid inlets (211) are evenly distributed circumferentially on the insulating plate (24). A first drainage groove (242) is provided on the insulating plate (24). The first drainage groove (242) is connected to the liquid inlet pipe (232) and the plurality of first liquid inlets (211) respectively. The support frame group (25) is connected to the proton exchange membrane (11). The electrode chamber (3) is formed between the support frame group (25) and the proton exchange membrane (11). The support frame group (25) is used to support and position the electrode assembly (12). The liquid outlet assembly (22) includes a liquid outlet pipe (221) and a flow guide frame (222). The liquid outlet pipe (221) is coaxially inserted into the liquid inlet pipe (232) and spaced apart from the liquid inlet pipe (232). The flow guide frame (222) is disposed in the electrode chamber (3) and located in the central region of the electrode chamber (3). The flow guide frame (222) is connected to the liquid outlet pipe (221). The flow guide frame (222) is used to gather the radially flowing electrolyte and guide it into the liquid outlet pipe (221).

2. The circular reference cell for monitoring electrode potential according to claim 1, characterized in that: The support frame assembly (25) includes a support plate frame (251) and an electrode frame (252) arranged sequentially. The support plate frame (251) and the electrode frame (252) are coaxially arranged with the liquid outlet assembly (22). The support plate frame (251) is connected to the insulating plate (24). The electrode frame (252) is connected to the proton exchange membrane (11) and arranged around the electrode chamber (3). The electrode assembly (12) includes a bipolar plate (121) and a working electrode (122). The bipolar plate (121) and the working electrode (122) are coaxially arranged in the electrode chamber (3). The support plate frame (251) and the electrode frame (252) clamp the bipolar plate (121). The working electrode (122) is arranged between the bipolar plate (121) and the proton exchange membrane (11).

3. The circular reference cell for monitoring electrode potential according to claim 2, characterized in that: The liquid inlet hole group (21) includes a second liquid inlet hole (212). Multiple second liquid inlets (212) are evenly distributed along the circumference of the support plate frame (251). The second liquid inlets (212) correspond one-to-one with the first liquid inlets (211) and are connected. Multiple second drainage grooves (2522) are provided on the side of the electrode frame (252) near the support plate frame (251). Multiple second drainage grooves (2522) are evenly distributed along the circumference of the electrode frame (252). The second liquid inlets (212) are connected to the second drainage grooves (2522).

4. The circular reference cell for monitoring electrode potential according to claim 3, characterized in that: The liquid inlet hole group (21) includes a third liquid inlet hole (213), which is evenly distributed along the circumference of the electrode frame (252). The third liquid inlet hole (213) corresponds to and is connected to the second liquid inlet hole (212). The electrode frame (252) is provided with a plurality of arc-shaped grooves (2521) evenly distributed along the circumference. The arc-shaped grooves (2521) are arranged in a corresponding manner to the third liquid inlet hole (213). The third liquid inlet hole (213) is connected to a plurality of second drainage grooves (2522) through the arc-shaped grooves (2521).

5. The circular reference cell for monitoring electrode potential according to claim 2, characterized in that: The bipolar plate (121) is provided with a tab (1211) on its periphery, and a slot (2511) is provided on the support plate frame (251). The tab (1211) is inserted into the slot (2511) and extends to the outside of the support plate frame (251).

6. The circular reference cell for monitoring electrode potential according to claim 1, characterized in that: The outlet pipe (221) has a receiving hole (2211) in its inner wall. The receiving hole (2211) is closed. A diagnostic component (26) is provided in the receiving hole (2211). One end of the diagnostic component (26) extends into the electrode chamber (3). The diagnostic component (26) is used to monitor multi-physics parameters.

7. The circular reference cell for monitoring electrode potential according to claim 6, characterized in that: The diagnostic component (26) includes a reference electrode wire (261) and a microporous ceramic plug (263). The reference electrode wire (261) is disposed in the receiving hole (2211). The microporous ceramic plug (263) is disposed at one end of the receiving hole (2211) near the electrode chamber (3) and connected to the reference electrode wire (261). The microporous ceramic plug (263) connects the reference electrode wire (261) and the electrolyte to achieve ion exchange.

8. The circular reference cell for monitoring electrode potential according to claim 6, characterized in that: The diagnostic component (26) includes a temperature sensor (262) disposed within the receiving hole (2211), and the temperature-sensing probe of the temperature sensor (262) extends to the central region of the electrode chamber (3).

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