Flow battery system performance recovery method and system

Abstract

The invention relates to the technical field of flow batteries, and provides a flow battery system performance recovery method and system, the system comprises a performance detection module, an electrolyte storage and supply module, an electrochemical reaction module, a fluid conveying and control module, a thermal management module, a circuit control module and a state monitoring module; the fluid conveying and control module comprises a valve group which is arranged through a plurality of groups of pipelines and is used for dynamically switching electrolyte paths; the circuit control module comprises a dual-power switch and is used for realizing lossless switching of electrode polarity; the valve group is in controlled linkage with the dual-power switch, the flow direction of the electrolyte and the polarity of the circuit are changed through logic switching, and traditional liquid mixing is replaced. According to the scheme, the dynamic switching of the positive and negative electrode attributes of the electrolyte is realized, the forced liquid mixing operation is eliminated, and the problems of electric energy loss and accompanying severe temperature rise before traditional switching are fundamentally avoided.

Description

Technical Field

[0001] This invention relates to the field of flow battery technology, and more specifically to a method and system for restoring the performance of a flow battery system. Background Technology

[0002] Flow battery energy storage technology, with its inherent safety, long cycle life, and outstanding capacity expansion capabilities, is gradually becoming one of the most promising technologies in the field of long-term energy storage. However, after large-scale systems are put into actual operation and undergo long-term cycling, byproduct impurities are inevitably generated inside the stack due to chemical reactions, causing battery capacity decay and affecting the system's ability to maintain power. Appropriate means are needed to restore the operating status.

[0003] Furthermore, the system requires forced mixing during periodic positive and negative electrode switching. This process not only incurs additional energy loss, but the accompanying exothermic mixing effect also causes the electrolyte temperature to rise rapidly. Without an efficient heat dissipation mechanism, the electrolyte temperature can easily exceed the safety threshold of 60°C within a short period, triggering a protective shutdown of the system and severely impacting the continuous operation capability and power supply reliability of the flow battery in grid-scale energy storage scenarios. Summary of the Invention

[0004] To address the problems existing in the background technology, this invention proposes a method and system for performance recovery of a flow battery system, which realizes dynamic switching of the positive and negative electrode properties of the electrolyte, eliminates forced mixing operation, and fundamentally avoids the problems of energy loss and accompanying drastic temperature rise before traditional switching.

[0005] To achieve the above objectives, the present invention adopts the following solution: A performance recovery system for a flow battery system includes a performance testing module, an electrolyte storage and supply module, an electrochemical reaction module, a fluid transport and control module, a thermal management module, a circuit control module, and a status monitoring module. The fluid delivery and control module includes a valve group arranged through multiple sets of pipelines for dynamic switching of the electrolyte path; the circuit control module includes a dual power switch for non-destructive switching of electrode polarity; the valve group and the dual power switch are controlled and linked, and the electrolyte flow direction and circuit polarity are changed through logic switching to replace the traditional mixing.

[0006] Optionally, the multiple sets of pipelines include a first pipeline, a second pipeline, a third pipeline, and a fourth pipeline. The first pipeline includes dual-connection valves A and B for selecting the positive electrode inlet path; the second pipeline includes dual-connection valves C and D for selecting the negative electrode inlet path; the third pipeline includes dual-connection valves E and F for selecting the positive electrode return path; and the fourth pipeline includes dual-connection valves G and H for selecting the negative electrode return path.

[0007] Optionally, the electrochemical reaction module includes an electrode stack, which includes a positive electrolyte chamber and a negative electrolyte chamber, which are separated by an ion exchange membrane.

[0008] Optionally, the thermal management module includes a heat exchanger, the fluid transport and control module further includes a positive electrode circulation pump and a negative electrode circulation pump, and the electrolyte storage and supply module includes a positive electrode storage tank and a negative electrode storage tank arranged symmetrically on the left and right sides, with an overflow pipe connecting the positive electrode storage tank and the negative electrode storage tank, and a valve I is provided on the overflow pipe; the bottom outlet of the positive electrode storage tank is connected to the inlet of the positive electrode electrolyte chamber in sequence through the positive electrode circulation pump and the first pipeline, and the top inlet of the positive electrode storage tank is connected to the outlet of the positive electrode electrolyte chamber in sequence through the heat exchanger and the third pipeline; the bottom outlet of the negative electrode storage tank is connected to the inlet of the negative electrode electrolyte chamber in sequence through the negative electrode circulation pump and the second pipeline, and the top inlet of the negative electrode storage tank is connected to the outlet of the negative electrode electrolyte chamber in sequence through the fourth pipeline.

[0009] Optionally, the performance testing module includes a voltmeter connected to the fuel cell stack and a controller with a built-in data comparison and calculation module. The voltmeter is electrically connected to the positive electrode storage tank and the negative electrode storage tank respectively through the controller. The voltmeter is also electrically connected to an energy storage converter PCS through the controller. The energy storage converter PCS is connected to the fuel cell stack.

[0010] Optionally, the dual power switch is a four-pole double-throw switch with mechanical interlock function, and its switching time is less than 100 milliseconds. The input terminal of the dual power switch is connected to a voltage regulator and rectifier, and the output terminal of the dual power switch is connected to the terminal of the fuel cell stack.

[0011] Optionally, the status monitoring module is symmetrically provided in two locations, respectively located between the first pipeline and the fuel cell stack, and between the second pipeline and the fuel cell stack; the status monitoring module includes a temperature sensor, a pressure gauge, and a flow detector.

[0012] A method for restoring the performance of a flow battery system includes the following steps: System startup steps: Inject electrolyte into the positive and negative electrode storage tanks and balance the liquid level to the preset height; start the heat exchanger to preheat the positive electrolyte in the positive electrode storage tank to the predetermined reaction temperature; Normal operation steps: The system enters the normal operation mode. The positive electrolyte in the positive electrode storage tank and the negative electrolyte in the negative electrode storage tank flow through the fuel cell stack along their respective normal circulation paths and undergo chemical reactions. At the same time, the system operating parameters are monitored in real time. The positive electrode path of the positive electrolyte is: positive electrode storage tank → circulation pump → open valve A → fuel cell stack positive inlet → fuel cell stack positive outlet → open valve E → heat exchanger → positive electrode storage tank. The negative electrode path of the negative electrolyte is: negative electrode storage tank → circulation pump → open valve → fuel cell stack negative inlet → fuel cell stack negative outlet → open valve G → negative electrode storage tank; Mode switching steps Step: When the preset switching trigger conditions are met, the switching process from the normal operation mode to the swap operation mode is executed. The switching process is performed in a preset sequence, with the valve group and circuit switch cooperating, including: at the first time point, closing the valve on the normal operation path and disconnecting the corresponding main circuit switch; at the second time point, opening the valve on the swap operation path and performing arc elimination; at the third time point, confirming that the fluid channel switching is complete and closing the circuit switch in the swap operation mode to complete the circuit polarity reversal; Swap operation steps: The system enters the swap operation mode, and the paths of the positive electrolyte in the positive electrode storage tank and the negative electrolyte in the negative electrode storage tank are swapped, flowing through the opposite electrodes of the stack respectively, and the electrode deposits are removed through the electrochemical regeneration mechanism, while the regeneration effect is monitored in real time; The positive electrode path of the negative electrode electrolyte is: positive electrode storage tank → circulation pump → open valve B → positive inlet of fuel cell stack → positive outlet of fuel cell stack → open valve F → heat exchanger → positive electrode storage tank; the negative electrode path of the positive electrode electrolyte is: negative electrode storage tank → circulation pump → open valve C → negative inlet of fuel cell stack → negative outlet of fuel cell stack → open valve H → negative electrode storage tank. Mode recovery steps: When the preset recovery conditions are met, the reverse switching process from the swapped operation mode back to the normal operation mode is executed to restore the normal operation of the system.

[0013] Optionally, the switching triggering condition includes at least one of the following: the system voltage efficiency drops below a first threshold, or the system cumulative running time reaches a first time threshold; the recovery condition includes at least one of the following: the cumulative running time in the swap operation mode reaches a second time threshold, or the system voltage efficiency recovers to above the second threshold.

[0014] Optionally, the collaborative operation in the mode switching step specifically includes: the method further includes a safety protection mechanism with full intervention, the safety protection mechanism including: temperature protection, when the electrolyte temperature reaches a first temperature threshold, the heat exchanger is forcibly stopped; when a higher second temperature threshold is reached, the system is shut down urgently; Pressure protection: When the system pressure exceeds the pressure threshold, the safety relief valve is opened; when the pressure difference between the positive and negative pipelines exceeds the pressure difference threshold, the flow balance regulation is triggered; Electrical protection: Arc detection is performed during circuit switching, and an overcurrent protection device is configured with a response time of less than 5ms.

[0015] The beneficial effects of this invention are as follows: First, this solution, through the design of four sets of pipelines and valve groups, achieves flexible and non-destructive switching of the positive and negative electrolyte flow directions, completely replacing the traditional forced mixing operation and fundamentally eliminating the problem of electrolyte temperature rise caused by the exothermic mixing process. Second, the system, through millisecond-level linkage control of the valve groups and dual power switches, completely eliminates the cumbersome work of directly physically switching (reversing) the electrode connections at the stack end in the traditional solution, greatly simplifying the electrical polarity switching process, eliminating the need for downtime construction, and significantly improving operational safety and efficiency.

[0016] Furthermore, this recovery method eliminates the need to disassemble the fuel cell stack or introduce external chemical reagents, simplifying the maintenance process and reducing reliance on professional personnel and maintenance costs. Periodic online performance recovery minimizes downtime and economic costs associated with component replacement or overhauls, thus demonstrating superior economic efficiency.

[0017] In addition, the system deeply integrates multiple modules such as fluid delivery, circuit switching, thermal management and status monitoring. The system can automatically judge and trigger the performance recovery process based on real-time monitored parameters, which improves the overall automation and intelligence level of the system. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall system of the present invention; Figure 2 This is a flowchart illustrating the overall system workflow of the present invention; Figure 3 This is a control diagram of the performance testing device in an embodiment of the present invention; Figure 4 This is a flowchart of the method of the present invention. Detailed Implementation

[0019] To make the present invention clearer and more understandable, the present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are only one implementation method and do not represent all embodiments.

[0020] Example 1 Combination Figures 1-3This embodiment provides a performance recovery system for a flow battery system, including a performance testing module, an electrolyte storage and supply module, an electrochemical reaction module, a fluid transport and control module, a thermal management module, a circuit control module, and a status monitoring module. The performance testing module collects voltage data in real time and links it with the system to implement a protection mechanism. The electrolyte storage and supply module is responsible for the independent storage and targeted transport of the electrolyte to avoid cross-contamination. The electrochemical reaction module is responsible for converting the chemical energy of the electrolyte into electrical energy and is a crucial site for energy conversion. The fluid transport and control module drives the electrolyte circulation and enables path switching. The thermal management module regulates the temperature of the positive electrode electrolyte to prevent precipitation. The circuit control module enables non-destructive switching of electrode polarity. The status monitoring module can monitor parameters in real time and display them in conjunction with the system.

[0021] Furthermore, the fluid delivery and control module includes a valve group arranged through multiple sets of pipelines for dynamic switching of the electrolyte path; the circuit control module includes a dual power switch, which only needs to be operated at the end of the system power supply circuit, completely eliminating the cumbersome work of physically swapping (reversing) the electrode connections of the fuel cell stack in the traditional solution; the valve group and the dual power switch are controlled and linked, changing the electrolyte flow direction and circuit polarity through logical switching. Therefore, the system can operate in two states: the normal mode is state 1, and the swapping mode is state 2, thus completely replacing the traditional forced mixing operation and fundamentally avoiding the power loss and accompanying severe temperature rise problems before the traditional switching.

[0022] In this embodiment, the multiple sets of pipelines include a first pipeline, a second pipeline, a third pipeline, and a fourth pipeline. The first pipeline includes dual-path connecting valves A and B for selecting the positive electrode inlet path; the second pipeline includes dual-path connecting valves C and D for selecting the negative electrode inlet path; the third pipeline includes dual-path connecting valves E and F for selecting the positive electrode return path; and the fourth pipeline includes dual-path connecting valves G and H for selecting the negative electrode return path. Through the combination of four sets of pipelines and logic-controlled valves, flexible interchange of the positive and negative electrolyte flow directions is achieved. Moreover, the valve logic switching directly changes the electrolyte flow direction, avoiding the energy loss and temperature rise risks caused by traditional mixing. Furthermore, when the state 1 signal is received by the valve group, valves A, D, E, and G are opened, and valves B, C, F, and H are closed; when the state 2 signal is received by the valve group, valves B, C, F, and H are opened, and valves A, D, E, and G are closed.

[0023] Specifically, the electrochemical reaction module includes a stack, which includes a positive electrolyte chamber and a negative electrolyte chamber, which are separated by an ion exchange membrane.

[0024] The fuel cell stack is the core unit of the electrochemical reaction. It consists of n individual cells connected in series. The electrolyte in the fuel cell stack undergoes a chemical reaction to realize the conversion of chemical energy and electrical energy, and generates direct current output.

[0025] The upper interface of the fuel cell stack is connected to a circuit control module. This module can switch electrode polarity without loss, enabling software-based electrode swapping. It mainly includes a voltage regulator / rectifier and a dual power switch. In this embodiment, the dual power switch is a four-pole double-throw switch with mechanical interlocking to prevent short circuits, and its switching time is less than 100 milliseconds. The internal structure of the four-pole double-throw switch is: Group 1, K1 (normally open) / K2 (normally closed); Group 2, K3 (normally closed) / K4 (normally open). The dual power switch is installed in the same cabinet as the converter, with a heat dissipation distance >10cm. The input port is connected to the voltage regulator / rectifier, and the output port is connected to the terminals of the fuel cell stack. The connection logic of the dual power switch is: In system operating state 1, K1 / K4 is closed → fuel cell stack positive terminal = P+; In system operating state 2: K2 / K3 is closed → fuel cell stack positive terminal = P-.

[0026] The core functions of a voltage regulator rectifier are AC / DC conversion (380VAC→48-120VDC), power factor correction (>0.95), and overvoltage / overcurrent protection. The voltage regulator rectifier is located inside the electrical control cabinet, with an external heatsink design. Its input port connects to a 50Hz three-phase power grid, and its output port connects to the input terminals of a dual power switch.

[0027] Specifically, the thermal management module includes a heat exchanger that specifically cools the positive electrode electrolyte (the negative electrode electrolyte does not pass through it), which can maintain the electrolyte within the optimal operating temperature range of 25-40℃ and prevent overheating from causing the precipitation of chemical reactants.

[0028] The fluid delivery and control module further includes a positive electrode circulation pump and a negative electrode circulation pump. The electrolyte storage and supply module includes a positive electrode storage tank and a negative electrode storage tank arranged symmetrically on the left and right. An overflow pipe connects the top of the positive electrode storage tank and the top of the negative electrode storage tank. The overflow pipe is equipped with valve I to connect the two tanks, so as to achieve dynamic liquid level balance and emergency pressure relief between the two tanks. The bottom outlet of the positive electrode storage tank is connected to the inlet of the positive electrode electrolyte chamber in sequence through the positive electrode circulation pump and the first pipeline. The top inlet of the positive electrode storage tank is connected to the outlet of the positive electrode electrolyte chamber in sequence through a heat exchanger and the third pipeline. The bottom outlet of the negative electrode storage tank is connected to the inlet of the negative electrode electrolyte chamber in sequence through the negative electrode circulation pump and the second pipeline. The top inlet of the negative electrode storage tank is connected to the outlet of the negative electrode electrolyte chamber in sequence through the fourth pipeline.

[0029] Furthermore, the positive electrode storage tank stores the positive electrode electrolyte and serves as a buffer container for the electrolyte circulation system, preventing mixing and achieving electrolyte volume balance through level control. The volume of the positive electrode storage tank is designed according to the power of the fuel cell stack (typically 3-5 times the stack capacity). Its bottom outlet connects to the inlet of the positive electrode circulation pump to deliver fresh electrolyte, while its top inlet connects to the outlet of the heat exchanger to receive electrolyte after the reaction. The negative electrode storage tank stores the negative electrode electrolyte and circulates synchronously with the positive electrode electrolyte to maintain ion balance. Physical isolation from the positive electrode storage tank prevents cross-contamination. The overflow pipe functions as a dynamic level balancing device. Signals are transmitted to the system via a pressure gauge and flow detector. When there is a difference in the circulation flow rates of the positive and negative electrode electrolytes, the level in a single storage tank rises, and the high-pressure side electrolyte automatically flows into the low-pressure side tank through the overflow pipe, after which the level returns to balance. Furthermore, when the gas in a certain storage tank increases suddenly (such as due to abnormal reaction), the overflow pipe can serve as a pressure relief channel to divert the overpressure gas to another storage tank.

[0030] It should be noted that the aforementioned positive electrode circulation pump, negative electrode circulation pump, and valve assembly together constitute the fluid delivery and control module. Furthermore, the positive electrode circulation pump provides 8-15 kPa pressure to drive electrolyte circulation, employing a magnetically driven sealed design. Its suction inlet connects to the bottom of the positive electrode storage tank, and its discharge outlet connects to a tee valve, specifically distributing to valves A and B. The negative electrode circulation pump drives independent circulation of the negative electrode electrolyte, with its flow rate controlled synchronously with the positive electrode circulation pump. It is located directly below the outlet of the negative electrode storage tank, symmetrically arranged with the positive electrode circulation pump. Its suction inlet connects to the bottom of the negative electrode storage tank, and its discharge outlet connects to a tee valve, distributing to valves C and D. Additionally, the valve assembly is located at the four critical corner nodes of the fuel cell stack, with a valve spacing of <50 cm to reduce flow resistance.

[0031] Specifically, the performance detection module includes a voltmeter connected to the fuel cell stack and a controller with a built-in data comparison and calculation module. The voltmeter is electrically connected to the positive and negative electrode storage tanks via the controller. The voltmeter is also electrically connected to a power storage converter (PCS) via the controller. The PCS is connected to the positive and negative terminals of the fuel cell stack via wires and is responsible for regulating the charging and discharging process of the flow battery. Furthermore, the input terminal of the voltmeter is directly connected to the positive and negative electrode wires of each individual cell in the electric thruster, collecting individual cell voltage data in real time and transmitting it to the controller. The controller compares the real-time voltage with a set value and performs calculations, outputting a signal to the output terminal connected to the PCS, the positive electrode circulation pump, and the negative electrode storage tank. This protection mechanism ensures that all individual cell voltages are maintained within a safe range; if an over-limit is detected, the controller immediately adjusts the PCS (reducing voltage or shutting down) and records the data; if necessary, the circulation pump is shut down to quickly cut off system operation and achieve battery protection.

[0032] The status monitoring module is symmetrically located in two places, one between the first pipeline and the fuel cell stack, and the other between the second pipeline and the fuel cell stack. Its core function is real-time monitoring and adaptive display of all parameters to ensure system safety. It includes temperature sensors, pressure gauges, and flow detectors, all centrally installed on the fuel cell stack outlet main pipe, less than 30cm from the fuel cell stack to ensure real-time monitoring. The status monitoring module can monitor the temperature, pressure, flow rate, liquid level of the positive and negative electrodes, as well as branch current and total voltage in real time for more precise operation.

[0033] Therefore, through the design of four sets of pipelines and valve groups, the system achieves flexible and non-destructive switching of the positive and negative electrolyte flow directions, completely replacing the traditional forced mixing operation and fundamentally eliminating the electrolyte temperature rise problem caused by the exothermic mixing process. The system, through millisecond-level linkage control of the valve groups and dual power switches, completely eliminates the cumbersome work of physically reversing (reversing) the electrode connections at the stack end in traditional solutions, significantly simplifying the electrical polarity switching process. It eliminates the need for downtime for construction, significantly improving operational safety and efficiency. Furthermore, it effectively dissolves deposits on the electrode surface and activates the electrode active materials, thereby extending the lifespan of the stack.

[0034] Example 2 Combination Figure 4 This embodiment, based on the system provided in Embodiment 1, provides a method for performance recovery of a flow battery system. This method achieves performance recovery of the flow battery without downtime through precise and coordinated fluid control, circuit switching, and intelligent monitoring. Specifically, it includes the following steps: System startup steps: Inject electrolyte into the positive electrode storage tank and the negative electrode storage tank, and balance the liquid level to the preset height; start the heat exchanger to preheat the positive electrode electrolyte in the positive electrode storage tank to the optimal reaction temperature of 30°C.

[0035] Routine Operation Procedure: The system enters the routine operation mode, i.e., state 1. The positive electrolyte in the positive electrode storage tank and the negative electrolyte in the negative electrode storage tank circulate among the storage tanks, circulation pump, valve group, fuel cell stack, and other components, undergoing a chemical reaction within the fuel cell stack. The routine circulation path for the positive electrolyte is: positive electrode storage tank → circulation pump → open valve A → fuel cell stack positive inlet → fuel cell stack positive outlet → open valve E → heat exchanger → positive electrode storage tank. The routine circulation path for the negative electrolyte is: negative electrode storage tank → circulation pump → open valve → fuel cell stack negative inlet → fuel cell stack negative outlet → open valve G → negative electrode storage tank. Temperature, pressure, and flow rate parameters are monitored in real time.

[0036] Mode switching steps: When the preset switching trigger conditions are met (voltage efficiency drops below 85% or cumulative operation reaches 500 hours), a manual start command is issued, and the switching process from the normal operation mode to the swapped operation mode is executed. The switching process is executed in a preset sequence, with the valve group and circuit switch working together, including: at 0ms, valves A, D, E, and G are closed, and circuits K1 / K4 are disconnected; at 20ms, valves B, C, F, and H are opened, and the electric arc is eliminated; at 50ms, the flow channel switching is completed, and circuits K2 / K3 are closed; at 100ms, the flow rate is stabilized, and the circuit polarity reversal is completed.

[0037] Switching operation steps: According to the overflow pipe balancing mechanism and circulation process, before the switching operation steps, the system has already switched through the valve group. At this time, the positive electrode storage tank stores the negative electrode electrolyte in a physical sense, and the negative electrode storage tank stores the positive electrode electrolyte in a physical sense.

[0038] When the system enters the swap operation mode, i.e., state 2, the physical path of the negative electrolyte to the positive electrode is: positive electrode storage tank → circulating pump → open valve B → positive inlet of fuel cell stack → positive outlet of fuel cell stack → open valve F → heat exchanger → positive electrode storage tank; the physical path of the positive electrolyte to the negative electrode is: negative electrode storage tank → circulating pump → open valve C → negative inlet of fuel cell stack → negative outlet of fuel cell stack → open valve H → negative electrode storage tank. In this operation mode, regardless of changes in electrolyte properties, since the heat exchanger is only installed on the logical positive electrode circuit, it ensures that the physical positive electrolyte requiring key temperature control (because it is more prone to precipitation) will not enter the heat exchanger when flowing through the logical negative electrode path in the swap mode, avoiding unnecessary cooling or thermal management chaos. At the same time, by physically switching the pipes and valves to change the flow direction, the traditional forced mixing operation is fundamentally replaced, avoiding the energy loss and risk of drastic temperature rise caused by mixing.

[0039] Mode recovery steps: When the preset recovery conditions are met (accumulated 24 hours of operation or voltage efficiency recovered to above 92%), the reverse switching process from the swapped operation mode back to the normal operation mode is executed. Accordingly, valves B, C, F and H are closed, valves A, D, E and G are opened, circuits K2 / K3 are disconnected, circuits K1 / K4 are closed, and the normal operation of the system is restored.

[0040] The method also includes a comprehensive safety protection mechanism, which includes: temperature protection, forced shutdown of the heat exchanger at 45℃, and emergency system shutdown at 50℃; pressure protection, opening of the safety relief valve when overpressure exceeds 0.6MPa, and triggering flow balance regulation when pressure difference > 0.1MPa; and electrical protection, including arc detection during switch switching and overcurrent protection response time < 5ms.

[0041] In summary, the recovery method described in this embodiment eliminates the need to disassemble the fuel cell stack or introduce external chemical reagents, simplifying the maintenance process and reducing reliance on professional personnel and maintenance costs. Through periodic online performance recovery, it reduces downtime and economic costs associated with component replacement or overhauls, thus demonstrating superior economic efficiency.

[0042] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A flow battery system performance recovery system, characterized by: The performance detection module, the electrolyte storage and supply module, the electrochemical reaction module, the fluid delivery and control module, the thermal management module, the circuit control module and the state monitoring module are included. The fluid delivery and control module contains a valve group arranged through multiple groups of pipelines for dynamic switching of electrolyte paths; the circuit control module includes a double power switch for realizing lossless switching of electrode polarity; the valve group and the double power switch are controlled and linked to change electrolyte flow direction and circuit polarity through logical switching for replacing traditional mixed liquid.

2. A flow battery system performance recovery system according to claim 1, wherein: The multiple groups of pipelines include a first pipeline, a second pipeline, a third pipeline and a fourth pipeline; the first pipeline includes double-path connection valves A and B for positive electrode liquid inlet path selection; the second pipeline includes double-path connection valves C and D for negative electrode liquid inlet path selection; the third pipeline includes double-path connection valves E and F for positive electrode liquid return path selection; and the fourth pipeline includes double-path connection valves G and H for negative electrode liquid return path selection.

3. A flow battery system performance recovery system according to claim 2, wherein: The electrochemical reaction module includes an electric pile, and the electric pile includes a positive electrolyte chamber and a negative electrolyte chamber, which are separated by an ion exchange membrane.

4. A flow battery system performance recovery system according to claim 3, wherein: The thermal management module includes a heat exchanger, the fluid delivery and control module further includes positive and negative circulating pumps, the electrolyte storage and supply module includes positive and negative storage tanks arranged in a left-right symmetrical manner, an overflow pipe is connected between the positive and negative storage tanks, and a valve I is arranged on the overflow pipe; a bottom outlet of the positive storage tank is connected to an inlet of the positive electrolyte chamber through the positive circulating pump and the first pipeline in sequence; a top inlet of the positive storage tank is connected to an outlet of the positive electrolyte chamber through the heat exchanger and the third pipeline in sequence; a bottom outlet of the negative storage tank is connected to an inlet of the negative electrolyte chamber through the negative circulating pump and the second pipeline in sequence; and a top inlet of the negative storage tank is connected to an outlet of the negative electrolyte chamber through the fourth pipeline.

5. A flow battery system performance recovery system according to claim 4, wherein: The performance detection module includes a voltage meter connected to the electric pile and a controller with a built-in data comparison operation module; the voltage meter is electrically connected to the positive and negative storage tanks through the controller; the voltage meter is further electrically connected to a power storage converter PCS through the controller; and the power storage converter PCS is connected to the electric pile.

6. A flow battery system performance recovery system according to claim 5, wherein: The double power switch is a four-blade double-throw switch with mechanical interlocking function, and the switching time is less than 100 milliseconds; a voltage stabilizer rectifier is connected to an input end of the double power switch; and an output end of the double power switch is connected to terminals of the electric pile.

7. A flow battery system performance recovery system according to claim 6, wherein: The state monitoring module is symmetrically arranged at two positions between the first pipeline and the electric pile and between the second pipeline and the electric pile; and the state monitoring module includes a temperature sensor, a pressure gauge and a flow detector.

8. A method of restoring performance of a flow battery system according to claim 7, wherein, The method includes the following steps: A system starting step: electrolyte is injected into the positive and negative storage tanks, and the liquid level is balanced to a preset height; the heat exchanger is started to preheat the positive electrolyte in the positive storage tank to a predetermined reaction temperature; The conventional operation step is that the system enters the conventional operation mode, the positive electrolyte in the positive electrolyte storage tank and the negative electrolyte in the negative electrolyte storage tank flow through the battery along the respective conventional circulation paths and perform chemical reactions, and the system operation parameters are monitored in real time, the positive electrolyte path is: positive electrolyte storage tank→circulation pump→opening valve A→battery positive inlet→battery positive outlet→opening valve E→heat exchanger→positive electrolyte storage tank, and the negative electrolyte path is: negative electrolyte storage tank→circulation pump→opening valve→battery negative inlet→battery negative outlet→opening valve G→negative electrolyte storage tank; the mode switching step is that when the preset switching trigger condition is met, the switching process from the conventional operation mode to the reverse operation mode is performed, the switching process performs the cooperation of the valve group and the circuit switch according to the preset time sequence, including: at a first time point, the valves on the conventional operation path are closed and the corresponding main circuit switch is disconnected; at a second time point, the valves on the reverse operation path are opened, and arc elimination is performed; at a third time point, it is confirmed that the fluid channel switching is completed, and the circuit switch in the reverse operation mode is closed, and the circuit polarity reversal is completed; the reverse operation step is that the system enters the reverse operation mode, the positive electrolyte in the positive electrolyte storage tank and the negative electrolyte in the negative electrolyte storage tank realize reverse, respectively flow through the opposite electrodes of the battery, and remove electrode deposits through the electrochemical regeneration mechanism, while the regeneration effect is monitored in real time; the positive electrolyte path of the negative electrolyte is: positive electrolyte storage tank→circulation pump→opening valve B→battery positive inlet→battery positive outlet→opening valve F→heat exchanger→positive electrolyte storage tank; the negative electrolyte path of the positive electrolyte is: negative electrolyte storage tank→circulation pump→opening valve C→battery negative inlet→battery negative outlet→opening valve H→negative electrolyte storage tank; The mode recovery step is that when the preset recovery condition is met, the reverse switching process from the reverse operation mode to the conventional operation mode is performed, and the conventional operation of the system is restored.

9. The method of claim 8, wherein: The switching trigger condition includes at least one of the following: the system voltage efficiency decreases to below a first threshold value, or the system cumulative operation time reaches a first time threshold value; the recovery condition includes at least one of the following: the cumulative operation time in the reverse operation mode reaches a second time threshold value, or the system voltage efficiency recovers to above a second threshold value.

10. The method of claim 8, wherein: The cooperative operation in the mode switching step specifically includes: the method further includes a safety protection mechanism that intervenes throughout the process, the safety protection mechanism includes: temperature protection, when the electrolyte temperature reaches a first temperature threshold value, the heat exchanger is forced to stop; when a higher second temperature threshold value is reached, the system is shut down urgently; pressure protection, when the system pressure exceeds the pressure threshold value, the safety pressure relief valve is opened; when the positive and negative pipe pressure difference exceeds the pressure difference threshold value, the flow balance adjustment is triggered; electrical protection, arc detection is performed during the switching process of the circuit switch, and an overcurrent protection device is configured, and the response time is less than 5ms.

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