A plate energy storage system integrating phase change thermal management and multiphysics monitoring

Abstract

This invention discloses a plate-type energy storage system integrating phase change thermal management and multi-physics field monitoring, belonging to the field of energy storage system technology. The key technical points are: it includes multiple battery stacks, a positive electrode circulation system, a negative electrode circulation system, and a negative electrode storage tank. Each battery stack includes: two phase change thermal management layers; a reaction unit sandwiched between the two phase change thermal management layers, the reaction unit including a diaphragm with composite current collectors on both sides, a positive electrode flow channel layer and a negative electrode flow channel layer respectively sealed and attached to both sides of the diaphragm, a positive electrode flow channel for positive electrode slurry flow formed between the positive electrode flow channel layer and the diaphragm, and a negative electrode flow channel for negative electrode slurry flow formed between the negative electrode flow channel layer and the diaphragm; and a multi-physics field sensing layer disposed above the double-sided current collectors for monitoring the temperature and voltage fields inside the reaction unit. This invention has the advantages of strong safety early warning capabilities and convenient maintenance.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, and more specifically, to a plate energy storage system that integrates phase change thermal management and multi-physics field monitoring. Background Technology

[0002] Lithium iron phosphate (LFP) batteries have become the dominant technology for electrochemical energy storage due to their high safety, long cycle life, and low cost. The optimal operating temperature range for LFP batteries is 25-35℃; deviating from this range will accelerate aging and performance degradation. As energy storage applications become more long-duration and large-scale, battery cells are becoming larger and system integration is increasing. However, the traditional three-tiered integrated architecture of "cell-module-battery pack" used in LFP batteries, with its fixed physical form and closed structure, presents a series of inherent bottlenecks that are difficult to overcome.

[0003] The current typical implementation method is a stacked or wound lithium iron phosphate cell and its system integration scheme. This scheme forms a fixed cell by stacking or winding the positive electrode, separator, and negative electrode in a Z-shape, welding tabs, and then encapsulating it in an aluminum shell or aluminum-plastic film, injecting electrolyte, and sealing it. Multiple cells are connected in series and parallel to form modules, and multiple modules are then integrated into a battery pack. For thermal management, external liquid cooling plates are placed at the bottom or side of the module or battery pack for heat dissipation. For state monitoring, thermocouples attached to the surface of a few cells are used to collect temperature data, and the battery management system (BMS) indirectly infers the internal state of the battery by collecting limited external temperature and overall voltage data.

[0004] However, the above solution has the following drawbacks:

[0005] 1. Lithium iron phosphate cells have a stacked internal structure, resulting in significant differences in thermal conductivity in different directions. Existing external liquid cooling plate solutions have long heat dissipation paths, high thermal resistance, and mostly cool from one side. This not only fails to eliminate the temperature gradient caused by anisotropy inside the cell, but also exacerbates the uneven temperature field, leading to localized overheating and poor consistency.

[0006] 2. Existing battery management systems can only collect temperature measurement points and overall voltage signals on the surface of the battery cell, and cannot reflect the true distribution of the temperature and voltage fields inside the cell. They lack the ability to detect early-stage problems within the cell, such as SEI film decomposition, localized micro-short circuits, and lithium plating, making it difficult to provide timely warnings in the early stages of faults.

[0007] 3. The battery cell is a non-removable sealed body. Local degradation or micro-damage can lead to the scrapping of the entire battery cell, resulting in a huge waste of resources.

[0008] 4. When thermal runaway occurs, the positive and negative electrode active materials inside the battery cell are always in contact with the electrolyte. The thermal runaway chain reaction cannot be physically cut off at the material level, and can only be remedial cooling by external fire-fighting measures.

[0009] Therefore, a new solution is needed to address the above problems. Summary of the Invention

[0010] In view of this, the purpose of the present invention is to provide a plate energy storage system that integrates phase change thermal management and multi-physics field monitoring to solve the above problems.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is: a plate-type energy storage system integrating phase change thermal management and multi-physics field monitoring, comprising multiple battery stacks, a positive electrode circulation system, a negative electrode circulation system, and a positive electrode storage tank for storing positive electrode slurry and a negative electrode storage tank for storing negative electrode slurry, each of the battery stacks comprising:

[0012] Two phase transition thermal management layers;

[0013] A reaction unit is sandwiched between two phase change thermal management layers. The reaction unit includes a diaphragm, a positive electrode flow channel layer and a negative electrode flow channel layer respectively sealed and attached to both sides of the diaphragm. A positive electrode flow channel for the flow of the positive electrode slurry is formed between the positive electrode flow channel layer and the diaphragm, and a negative electrode flow channel for the flow of the negative electrode slurry is formed between the negative electrode flow channel layer and the diaphragm.

[0014] A multiphysics sensing layer is used to monitor the temperature and voltage fields inside the reaction unit;

[0015] The positive electrode circulation system connects the positive electrode storage tank and the positive electrode flow channel, and the negative electrode circulation system connects the negative electrode storage tank and the negative electrode flow channel. Both the positive electrode circulation system and the negative electrode circulation system are equipped with drain valves. When the multiphysics field sensing layer detects signs of impending thermal runaway, the drain valves open to discharge the positive electrode slurry in the positive electrode flow channel and the negative electrode slurry in the negative electrode flow channel.

[0016] Preferably, the phase change thermal management layer includes a support body and a phase change material disposed within the support body, wherein the phase change temperature of the phase change material is 25°C-35°C.

[0017] Preferably, it also includes a coolant circulation pipeline, and a heat exchange tube is provided inside the phase change heat management layer. The heat exchange tube is connected to the external first cold and heat source system through the coolant circulation pipeline.

[0018] Preferably, the side of the diaphragm facing the positive electrode channel layer is composited with a positive electrode current collector, and the side facing the negative electrode channel layer is composited with a negative electrode current collector. A positive electrode tab is connected to the positive electrode current collector, and a negative electrode tab is connected to the negative electrode current collector.

[0019] Preferably, it also includes a battery management system, wherein the multiphysics sensing layer includes a thermocouple array and a voltage probe grid;

[0020] The thermocouple array includes multiple thermocouple measuring points integrated in a matrix on the positive electrode current collector and the negative electrode current collector. Each thermocouple measuring point is electrically connected to the battery management system and is used to monitor the temperature field inside the reaction unit.

[0021] The voltage probe grid includes multiple voltage measurement points integrated in a matrix on the positive electrode current collector and the negative electrode current collector. Each voltage measurement point is electrically connected to the battery management system and is used to monitor the voltage field inside the reaction unit.

[0022] Preferably, the plurality of thermocouple measuring points and the plurality of voltage measuring points are arranged in a one-to-one ratio in terms of quantity and location.

[0023] Preferably, the positive electrode circulation system includes an inlet manifold, an outlet manifold, and a slurry pump installed on the outlet manifold. An inlet is located at the top of the positive electrode flow channel layer, and an outlet is located at the bottom. Both the inlet and outlet are connected to the positive electrode flow channel. The inlet is connected to the inlet manifold via an inlet hose, and the outlet is connected to the outlet manifold via an outlet hose. The inlet and outlet manifolds are respectively connected to the positive electrode storage tank. The slurry pump is connected to the side of the outlet manifold closest to the positive electrode storage tank. An inert gas inlet valve is installed on the side of the inlet manifold closest to the inlet. A drain pipe is connected to the outlet manifold between the slurry pump and the outlet. A drain valve is installed on the drain pipe. The negative electrode circulation system has the same structure as the positive electrode circulation system.

[0024] Preferably, both the positive electrode storage tank and the negative electrode storage tank are equipped with an insulation layer and a water-cooling jacket. The water-cooling jacket is connected to an external second cold and heat source system to maintain the positive electrode slurry and the negative electrode slurry at 25℃-35℃.

[0025] Preferably, the positive electrode flow channel layer includes a first thermally conductive substrate and a first slot formed on the first thermally conductive substrate, the first slot being open towards the diaphragm, and the positive electrode flow channel being formed between the first slot and the diaphragm; the negative electrode flow channel layer includes a second thermally conductive substrate and a second slot formed on the second thermally conductive substrate, the second slot being open towards the diaphragm, and the negative electrode flow channel being formed between the second slot and the diaphragm; and both the first thermally conductive substrate and the second thermally conductive substrate are provided with an electrically insulating and thermally conductive coating.

[0026] Preferably, the membrane is an ion exchange membrane.

[0027] Compared with existing technologies, the advantages of the plate energy storage system integrating phase change thermal management and multiphysics monitoring disclosed in this invention are:

[0028] 1. By sandwiching two phase change heat management layers on both sides of the reaction unit, the phase change heat management layers can perform bi-directional symmetrical heat exchange on the reaction unit, avoiding the large internal temperature gradient and local hot spots caused by unilateral heat dissipation, effectively improving temperature uniformity. Moreover, the phase change heat management layers can passively absorb or release heat within the phase change temperature range without moving parts or external energy, achieving zero-power uniform temperature control.

[0029] 2. By integrating thermocouple arrays and voltage probe grids onto the positive and negative current collectors, the temperature and voltage fields inside the reaction unit can be monitored in situ and in real time, enabling the detection of internal anomalies in the very early stages of a fault and effectively improving safety early warning capabilities.

[0030] 3. The positive electrode flow channel layer and the negative electrode flow channel layer are respectively sealed and bonded to the diaphragm to form a positive electrode flow channel for the positive electrode slurry and a negative electrode flow channel for the negative electrode slurry. The positive electrode slurry and the negative electrode slurry directly wet the diaphragm during circulation. The lithium ion transport path is short and the reaction efficiency is high. The flowing slurry can continuously remove the waste heat of the reaction. At the same time, the slurry is fluid and replaceable. Only the aged slurry needs to be replaced to restore the system capacity. The hardware body such as the reaction unit and the phase change heat management layer can be used permanently, which has the advantage of convenient maintenance.

[0031] 4. When the multi-physics sensing layer detects that the temperature change rate in a certain area exceeds the set threshold and the voltage change rate in that area also shows an abnormality, or the local potential difference dispersion of multiple adjacent areas exceeds the set threshold, and it is judged as a precursor to thermal runaway, the drain valve opens to discharge the positive electrode slurry in the positive electrode channel and the negative electrode slurry in the negative electrode channel, thereby achieving physical separation of the reactants and actively cutting off the thermal runaway chain reaction at the material level, effectively improving the system's active safety protection capability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of the plate energy storage system integrating phase change thermal management and multiphysics monitoring according to an embodiment of this application;

[0034] Figure 2 This is a schematic diagram of the battery stack structure according to an embodiment of this application;

[0035] Figure 3 This is a partially enlarged schematic diagram of the multiphysics sensing layer in an embodiment of this application.

[0036] The numbers or letters in the attached diagram represent the names of the corresponding components:

[0037] 1. Battery stack; 11. Positive electrode flow channel layer; 12. Separator; 13. Negative electrode flow channel layer; 14. Support body; 15. Phase change material; 16. Heat exchange tube; 17. Multiphysics field sensing layer; 171. Voltage measuring point; 172. Thermocouple measuring point; 173. Resistor; 174. Fuse; 18. Positive electrode current collector; 19. Negative electrode current collector; 2. Positive electrode storage tank; 21. Water cooling jacket; 3. Negative electrode storage tank; 4. Positive electrode circulation system; 41. Inlet manifold; 42. Outlet manifold; 43. Slurry pump; 44. Inlet hose; 45. Outlet hose; 46. Drain pipe; 47. Drain valve; 48. Inert gas inlet valve; 5. Negative electrode circulation system; 6. Coolant circulation pipeline; 7. First cold and heat source system. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described through specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] Please see Figure 1 , Figure 2 and Figure 3This application provides a plate-type energy storage system integrating phase change thermal management and multiphysics monitoring, including multiple battery stacks 1, a positive electrode circulation system 4, a negative electrode circulation system 5, a positive electrode storage tank 2 for storing positive electrode slurry, and a negative electrode storage tank 3 for storing negative electrode slurry. Each battery stack 1 includes two phase change thermal management layers and a reaction unit, with the reaction unit sandwiched between the two phase change thermal management layers to form a sandwich stack structure. Multiple battery stacks 1 can be stacked sequentially in a horizontal direction to form a larger-scale battery stack 1 body.

[0040] The reaction unit includes a separator 12, a positive electrode flow channel layer 11, and a negative electrode flow channel layer 13. The positive electrode flow channel layer 11 and the negative electrode flow channel layer 13 are respectively sealed and bonded to both sides of the separator 12. A positive electrode flow channel for the flow of positive electrode slurry is formed between the positive electrode flow channel layer 11 and the separator 12, and a negative electrode flow channel for the flow of negative electrode slurry is formed between the negative electrode flow channel layer 13 and the separator 12. Specifically, the positive electrode flow channel layer 11 includes a first thermally conductive substrate and a first slot formed on the first thermally conductive substrate. The first slot is open towards the separator 12, and a positive electrode flow channel is formed between the first slot and the separator 12. The negative electrode flow channel layer 13 includes a second thermally conductive substrate and a second slot formed on the second thermally conductive substrate. The second slot is open towards the separator 12, and a negative electrode flow channel is formed between the second slot and the separator 12. The first and second thermally conductive substrates are preferably made of the same lightweight, high thermal conductivity metal. Both substrates have an electrically insulating and thermally conductive coating on their surfaces, with a thickness controlled between 10 μm and 100 μm. This coating can be an anodized layer, a diamond-like carbon coating, or a ceramic coating. The positive electrode flow channel layer 11 and the negative electrode flow channel layer 13 are made of the same material; only the flow channel structure can be optimized according to the flow characteristics of the positive and negative electrode slurries. The first and second thermally conductive substrates are sealed to the diaphragm 12 using gaskets to prevent leakage of the positive and negative electrode slurries. The shapes of the positive and negative electrode flow channels can be serpentine or vein-shaped, or porous foam metal or sintered metal felt can be used to fill the chambers to form permeation channels. In another embodiment, the positive electrode channel layer 11 and / or the negative electrode channel layer 13 may also adopt a corrugated plate structure, which is formed by stamping or etching into herringbone, sinusoidal or trapezoidal corrugations, with the crests contacting the diaphragm 12 and the troughs forming the positive electrode channel or the negative electrode channel.

[0041] The separator 12 is an ion exchange membrane that allows lithium ions to conduct while isolating electrons; it can be a polymer separator 12 or a ceramic separator 12. A positive current collector 18 is laminated on the side of the separator 12 facing the positive electrode channel layer 11, and a negative current collector 19 is laminated on the side facing the negative electrode channel layer 13. The positive current collector 18 is preferably a carbon-coated aluminum mesh, and the negative current collector 19 is preferably a carbon-coated copper mesh. A positive electrode tab is connected to the positive current collector 18, and a negative electrode tab is connected to the negative current collector 19. The positive and negative electrode tabs are used to conduct the current generated by the electrochemical reaction outwards. In another embodiment, the positive current collector 18 and the negative current collector 19 can also be made of stainless steel mesh, nickel-plated steel mesh, or titanium mesh, depending on conductivity and corrosion resistance requirements, forming a composite current collector structure with carbon-coated aluminum foil or copper foil.

[0042] The positive electrode slurry is composed of nano-lithium iron phosphate particles, a conductive agent, and an electrolyte, while the negative electrode slurry is composed of nano-graphite or hard carbon particles, a conductive agent, and an electrolyte. When the positive electrode slurry flows in the positive electrode channel, it directly wets the side of the separator 12 facing the positive electrode channel layer 11, and when the negative electrode slurry flows in the negative electrode channel, it directly wets the side of the separator 12 facing the negative electrode channel layer 13.

[0043] The system also includes a battery management system (BMS). The circuit board of the battery management system integrates multiple resistors 173 and multiple fuses 174. The multi-physics sensing layer 17 includes a thermocouple array and a voltage probe grid. The circuit board of the battery management system also integrates a temperature acquisition circuit for voltage acquisition circuits, which adopts existing technology and will not be described in detail here.

[0044] The thermocouple array includes multiple thermocouple measuring points 172 integrated in a matrix on the positive current collector 18 and the negative current collector 19. Each thermocouple measuring point 172 is electrically connected to the temperature acquisition circuit of the battery management system for monitoring the temperature field inside the reaction unit. In this embodiment, the thermocouple measuring points 172 are NTC probes, which are attached to the surface of the positive current collector 18 or the negative current collector 19 with thermally conductive insulating adhesive. The NTC probes have their own insulating layer, providing electrical isolation between them and the positive current collector 18 or the negative current collector 19.

[0045] The voltage probe grid includes multiple voltage measurement points 171 integrated in a matrix on the positive current collector 18 and the negative current collector 19. In this embodiment, the voltage measurement points 171 are metal contacts soldered to the positive current collector 18 or the negative current collector 19. The surface of the metal contacts is provided with an anti-corrosion coating to prevent corrosion of the metal contacts by the positive or negative electrode slurry. Each voltage measurement point 171 is electrically connected to the voltage acquisition circuit of the battery management system through a wire. On the circuit board of the battery management system, the wire corresponding to each voltage measurement point is connected in series with one end of a resistor, and the other end of the resistor is connected in series with one end of a fuse 174. The other end of the fuse 174 corresponding to the first voltage measurement point is electrically connected to a common reference potential point, and the other ends of the fuses 174 corresponding to the remaining voltage measurement points 171 are electrically connected to one end of the resistor 173 corresponding to the previous voltage measurement point 171. The other ends of each fuse are also electrically connected to the voltage acquisition circuit of the battery management system. A common reference potential point can be connected to the negative electrode tab or the negative electrode current collector 19, using the potential of the negative electrode tab as the reference potential for each voltage measurement point 171. The battery management system acquires the voltage signal across the resistor 173 corresponding to each voltage measurement point 171 through the voltage acquisition circuit, obtains the potential difference between each voltage measurement point 171, and then calculates the potential of each voltage measurement point 171 relative to the common reference potential point, thus obtaining the voltage field distribution inside the reaction unit. The collaborative analysis of the acquired temperature field data and voltage field data is used to determine the uniformity of the electrochemical reaction and identify precursory characteristics of thermal runaway.

[0046] Furthermore, multiple thermocouple measuring points 172 and multiple voltage measuring points 171 are arranged in a one-to-one correspondence in quantity and location, meaning that the planar position of each voltage measuring point 171 corresponds one-to-one with the planar position of a thermocouple measuring point 172. Each location point simultaneously possesses temperature and voltage data, enabling coordinated monitoring of the temperature and voltage fields at the same point, thus achieving coordinated acquisition and correlation analysis of temperature and voltage signals at the same spatial location. Its early warning principle is as follows: when an early anomaly such as a local micro-short circuit, lithium plating, or SEI film decomposition occurs in a certain area within the reaction unit, the local potential difference measured by the corresponding voltage measuring point 171 in that area will show an abnormal decrease, while the temperature measured by the corresponding thermocouple measuring point 172 in that area will show an abnormal increase. By comparing the rate of temperature change and the rate of voltage change at the same location, the battery management system can more accurately determine the fault type and location, achieving early warning of thermal runaway.

[0047] Furthermore, as an independent voltage measurement method, voltage measurement leads are directly drawn between the positive and negative electrodes of each reaction unit to form unit-level terminal voltage monitoring. This unit-level terminal voltage measurement complements the local potential difference distribution within the reaction unit measured by the voltage probe grid: the unit-level terminal voltage provides the overall voltage of each complete reaction unit, used to determine the overall state of charge of the reaction unit; the voltage probe grid provides the local potential difference distribution of each sub-region within the reaction unit, used to locate polarization inhomogeneities or local anomalies within the reaction unit. The combination of these two methods enables multi-scale assessment of the battery state from the overall reaction unit to its internal local dimensions. The collected temperature and voltage field data are reported to the battery management system for assessing local health status and early fault diagnosis.

[0048] In another embodiment, distributed temperature measurement can also be replaced by optical fibers engraved with Bragg grating arrays. The optical fibers are buried inside the phase change thermal management layer or in the sidewalls of the positive current collector 18 and the negative current collector 19 to achieve quasi-distributed temperature measurement.

[0049] The phase change heat management layer includes a support body 14 and a phase change material 15 disposed within the support body 14. In this embodiment, the support body 14 is a sealed shell, and the phase change material 15 is encapsulated within the shell. The phase change temperature of the phase change material 15 is 25℃-35℃. In another embodiment, the support body 14 may also be a porous expanded graphite skeleton, and the phase change material 15 is impregnated within the porous expanded graphite skeleton. The phase change material 15 may also be an inorganic hydrate or other materials capable of achieving efficient phase change heat absorption within the range of 25℃-35℃. This system also includes a coolant circulation pipe 6. A heat exchange tube 16 is disposed inside the phase change heat management layer, and the heat exchange tube 16 is connected to the external first cold and heat source system 7 through the coolant circulation pipe 6. When the phase change material 15 is completely melted and the passive heat storage capacity is exhausted, the battery management system activates the external first cold and heat source system 7, so that the coolant flows through the heat exchange tube 16 to perform forced convection active heat dissipation on the battery stack 1; when auxiliary heating is required for cold start in winter, the battery management system activates the external first cold and heat source system 7, so that the heating fluid flows through the heat exchange tube 16 to perform active heating on the battery stack 1.

[0050] The positive electrode circulation system 4 connects the positive electrode storage tank 2 to the positive electrode flow channel, and the negative electrode circulation system 5 connects the negative electrode storage tank 3 to the negative electrode flow channel. Specifically, the positive electrode circulation system 4 includes an inlet manifold 41, an outlet manifold 42, and a slurry pump 43 installed on the outlet manifold 42. The top of the positive electrode flow channel layer 11 has an inlet port, and the bottom has an outlet port, both of which are connected to the positive electrode flow channel. The inlet port is connected to the inlet manifold 41 via an inlet hose 44, and the outlet port is connected to the outlet manifold 42 via an outlet hose 45. The inlet manifold 41 and the outlet manifold 42 are respectively connected to the positive electrode storage tank 2. The slurry pump 43 is connected to the side of the outlet manifold 42 near the positive electrode storage tank 2, forming a positive electrode circulation loop. An inert gas inlet valve 48 is installed on the side of the inlet manifold 41 near the inlet port, and the inert gas inlet valve 48 is connected to an external nitrogen source via a valve. A drain pipe 46 is connected to the main outlet pipe 42 between the slurry pump 43 and the outlet, and a drain valve 47 is installed on the drain pipe 46. The negative electrode circulation system 5 has the same structure as the positive electrode circulation system 4, and will not be described in detail here.

[0051] Both the positive electrode storage tank 2 and the negative electrode storage tank 3 are equipped with insulation layers and water-cooled jackets 21. The water-cooled jackets 21 are connected to an external second heat source system to maintain the positive and negative electrode slurries at 25℃-35℃. The positive electrode storage tanks 2 and 3 are far from the heat-generating reaction zone, and the centrally stored positive and negative electrode slurries have high heat capacity and minimal temperature fluctuations. Only extremely low power consumption is required to maintain all the positive and negative electrode slurries within the optimal temperature range.

[0052] During normal operation, the slurry pump 43 in the positive electrode circulation system 4 drives the positive electrode slurry to circulate in the positive electrode circulation loop, and the slurry pump 43 in the negative electrode circulation system 5 drives the negative electrode slurry to circulate in the negative electrode circulation loop. When the positive and negative electrode slurries flow through the reaction unit, an electrochemical reaction occurs, outputting electrical energy. The phase change material 15 in the phase change thermal management layer passively absorbs the residual heat of the reaction and gradually melts into a liquid state, maintaining a constant temperature within the optimal temperature range. Once the phase change material 15 has completely melted, the external first heat source system 7 can be activated, providing auxiliary heat dissipation through the heat exchange tube 16. In low-temperature environments, when the system starts, the phase change material 15 releases its stored latent heat of solidification, or the external first heat source system 7 provides heating liquid through the heat exchange tube 16 to preheat the flowing positive and negative electrode slurries, achieving rapid cold start. The multiphysics sensing layer 17 collects temperature and voltage field data in real time and reports them to the battery management system.

[0053] When the multiphysics sensing layer 17 detects an abnormal surge in local temperature or abnormal fluctuations in voltage data, and the battery management system determines this as a precursor to thermal runaway, it immediately triggers the simultaneous opening of the drain valve 47 and the inert gas inlet valve 48 in the positive electrode circulation system 4 and the negative electrode circulation system 5. Specifically, the determination criteria are: the rate of temperature change measured at thermocouple point 172 exceeds a set threshold and / or an abnormal drop in local voltage measured at voltage point 171; these conditions are then considered precursors to thermal runaway. Under gravity, the positive electrode slurry in the positive electrode channel is rapidly discharged into the positive electrode storage tank 2 through the drain pipe 46 in the positive electrode circulation system 4. Similarly, the negative electrode slurry in the negative electrode channel is rapidly discharged into the negative electrode storage tank 3 through the drain pipe 46 in the negative electrode circulation system 5. Simultaneously, nitrogen gas enters from the highest point of the main inlet pipe 41 in the positive electrode circulation system 4, flowing along the circulation pipeline of the positive electrode circulation system 4 to the upper part of the battery stack 1 and the positive electrode storage tank 2, balancing the discharge pressure and isolating air to ensure smooth reflux of the positive electrode slurry by gravity. Nitrogen gas also enters from the highest point of the main inlet pipe 41 in the negative electrode circulation system 5, flowing along the circulation pipeline of the negative electrode circulation system 5 to the upper part of the battery stack 1 and the negative electrode storage tank 3, balancing the discharge pressure and isolating air to ensure smooth reflux of the negative electrode slurry by gravity. This physical separation of the positive and negative electrode slurries eliminates the material basis for the thermal runaway chain reaction, effectively preventing thermal runaway. In another embodiment, the outlet of the drain valve 47 can also be connected to a dedicated emergency relief tank, which is pre-filled with passivating or heat-absorbing materials to further enhance safety.

[0054] When the system experiences aging and capacity decay of the positive and negative electrode slurries due to long-term operation, the slurry pumps 43 in the positive electrode circulation system 4 and the negative electrode circulation system 5 are shut down. The old positive and negative electrode slurries are then removed using external equipment, and fresh, pre-charged positive and negative electrode slurries are injected to restore the system capacity. The core hardware components, such as the reaction unit, phase change thermal management layer, inlet manifold 41, outlet manifold 42, inlet hose 44, and outlet hose 45, do not suffer wear and tear and can be used permanently, effectively reducing operating costs.

[0055] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A plate-type energy storage system integrating phase change thermal management and multiphysics field monitoring, comprising multiple battery stacks, a positive electrode circulation system, a negative electrode circulation system, and a positive electrode storage tank for storing positive electrode slurry and a negative electrode storage tank for storing negative electrode slurry, characterized in that: Each of the battery stacks includes: Two phase transition thermal management layers; A reaction unit is sandwiched between two phase change thermal management layers. The reaction unit includes a diaphragm, a positive electrode flow channel layer and a negative electrode flow channel layer respectively sealed and attached to both sides of the diaphragm. A positive electrode flow channel for the flow of the positive electrode slurry is formed between the positive electrode flow channel layer and the diaphragm, and a negative electrode flow channel for the flow of the negative electrode slurry is formed between the negative electrode flow channel layer and the diaphragm. A multiphysics sensing layer is used to monitor the temperature and voltage fields inside the reaction unit; The positive electrode circulation system connects the positive electrode storage tank and the positive electrode flow channel, and the negative electrode circulation system connects the negative electrode storage tank and the negative electrode flow channel. Both the positive electrode circulation system and the negative electrode circulation system are equipped with drain valves. When the multiphysics field sensing layer detects signs of impending thermal runaway, the drain valves open to discharge the positive electrode slurry in the positive electrode flow channel and the negative electrode slurry in the negative electrode flow channel.

2. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 1, characterized in that: The phase change thermal management layer includes a support body and a phase change material disposed within the support body, wherein the phase change temperature of the phase change material is 25℃-35℃.

3. The plate energy storage system integrating phase change thermal management and multiphysics field monitoring according to claim 2, characterized in that: It also includes a coolant circulation pipeline, and a heat exchange tube is provided inside the phase change heat management layer. The heat exchange tube is connected to the external first cold and heat source system through the coolant circulation pipeline.

4. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 1, characterized in that: The diaphragm has a positive current collector mesh on the side facing the positive current channel layer and a negative current collector mesh on the side facing the negative current channel layer. A positive electrode tab is connected to the positive current collector mesh, and a negative electrode tab is connected to the negative current collector mesh.

5. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 4, characterized in that: It also includes a battery management system, and the multiphysics sensing layer includes a thermocouple array and a voltage probe grid; The thermocouple array includes multiple thermocouple measuring points integrated in a matrix on the positive electrode current collector and the negative electrode current collector. Each thermocouple measuring point is electrically connected to the battery management system and is used to monitor the temperature field inside the reaction unit. The voltage probe grid includes multiple voltage measurement points integrated in a matrix on the positive electrode current collector and the negative electrode current collector. Each voltage measurement point is electrically connected to the battery management system and is used to monitor the voltage field inside the reaction unit.

6. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 5, characterized in that: The multiple thermocouple measuring points and the multiple voltage measuring points are arranged in a one-to-one ratio in terms of both quantity and location.

7. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 1, characterized in that: The positive electrode circulation system includes an inlet manifold, an outlet manifold, and a slurry pump installed on the outlet manifold. An inlet is located at the top of the positive electrode flow channel layer, and an outlet is located at the bottom. Both the inlet and outlet are connected to the positive electrode flow channel. The inlet is connected to the inlet manifold via an inlet hose, and the outlet is connected to the outlet manifold via an outlet hose. The inlet and outlet manifolds are respectively connected to the positive electrode storage tank. The slurry pump is connected to the outlet manifold on the side near the positive electrode storage tank. An inert gas inlet valve is installed on the inlet manifold on the side near the inlet. A drain pipe is connected to the outlet manifold between the slurry pump and the outlet, and a drain valve is installed on the drain pipe. The negative electrode circulation system has the same structure as the positive electrode circulation system.

8. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 1, characterized in that: Both the positive electrode storage tank and the negative electrode storage tank are equipped with a heat insulation layer and a water-cooling jacket. The water-cooling jacket is connected to an external second cold and heat source system to maintain the positive electrode slurry and the negative electrode slurry at 25℃-35℃.

9. The plate energy storage system integrating phase change thermal management and multiphysics field monitoring according to claim 1, characterized in that: The positive electrode flow channel layer includes a first thermally conductive substrate and a first slot formed on the first thermally conductive substrate. The first slot is open towards the diaphragm opening, and the positive electrode flow channel is formed between the first slot and the diaphragm. The negative electrode flow channel layer includes a second thermally conductive substrate and a second slot formed on the second thermally conductive substrate. The second slot is open towards the diaphragm opening, and the negative electrode flow channel is formed between the second slot and the diaphragm. The surfaces of the first thermally conductive substrate and the second thermally conductive substrate are both provided with an electrically insulating and thermally conductive coating.

10. The plate energy storage system integrating phase change thermal management and multiphysics monitoring according to claim 1, characterized in that: The diaphragm is an ion exchange membrane.

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