Battery energy storage system and method thereof

Abstract

The application belongs to the technical field of energy storage equipment, and particularly relates to a battery energy storage system and a method thereof, which comprises a controller, a cabinet, an energy storage battery module arranged in the cabinet, a power-off module for controlling the on-off of the energy storage battery module and a load or a charging power supply, and a heat dissipation system for dissipating heat for the energy storage battery module; the heat dissipation system comprises a liquid cooling mechanism for liquid cooling of the energy storage battery module, a supply mechanism for supplying cooling medium to the liquid cooling mechanism, and a heat exchange return mechanism for cooling the cooling medium flowing through the energy storage battery module and returning the cooling medium to the supply mechanism; the energy storage battery module comprises a cell shell and a plurality of cell pieces arranged horizontally and side by side in the cell shell; a heat dissipation gap is arranged between the two adjacent cell pieces, and a heat exchange end of the liquid cooling mechanism extends into the heat dissipation gap and is attached to the cell pieces on both sides of the heat dissipation gap; the application can realize internal core temperature of the energy storage battery module, has good cooling effect, and effectively guarantees stable operation of the energy storage equipment.

Description

Technical Field

[0001] This invention relates to the field of energy storage equipment technology, and in particular to a battery energy storage system and method thereof. Background Technology

[0002] In the field of energy storage technology, the application of energy storage battery packs is becoming increasingly important, especially in electric vehicles, grid energy storage, and renewable energy systems. However, the performance and safety of energy storage batteries largely depend on the effectiveness and rationality of their thermal management systems. With the advancement of battery technology, the energy density of batteries is constantly increasing, which leads to a significant increase in the heat generated during charging and discharging. Therefore, heat dissipation has become a crucial technical challenge.

[0003] Currently, traditional heat dissipation methods are all based on air cooling. While these methods can meet heat dissipation requirements to a certain extent, they are often inefficient and ineffective when dealing with high-performance battery packs. This results in a persistently high risk of spontaneous combustion of the battery packs and makes it difficult to ensure that the batteries can operate stably and continuously within the optimal temperature range. Summary of the Invention

[0004] The purpose of this invention is to provide a battery energy storage system and method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a battery energy storage system and method, the device comprising a controller, a cabinet, an energy storage battery module disposed within the cabinet, a power-off module for controlling the connection and disconnection of the energy storage battery module with a load or charging power supply, and a heat dissipation system for cooling the energy storage battery module; the heat dissipation system includes a liquid cooling mechanism for liquid cooling the energy storage battery module, a supply mechanism for supplying a cooling medium to the liquid cooling mechanism, and a heat exchange return mechanism for cooling the cooling medium flowing through the energy storage battery module and returning it to the supply mechanism; the energy storage battery module includes a cell housing and a plurality of battery cells arranged horizontally side by side within the cell housing; a heat dissipation gap is provided between each pair of adjacent battery cells, and the heat exchange end of the liquid cooling mechanism extends into the heat dissipation gap and is in contact with the battery cells on both sides thereof.

[0006] The battery energy storage system and method of the present invention, wherein the liquid cooling mechanism is further used to trigger the power-off module to disconnect the load or charging power supply from the energy storage battery module.

[0007] The battery energy storage system and method of the present invention include a liquid cooling mechanism comprising a heat exchange plate having a accommodating cavity for the flow of a cooling medium, and a drive unit for driving the heat exchange plate to move up and down; the lower end of the heat exchange plate forms the heat exchange end and extends into the heat dissipation gap and is in contact with the battery cells on both sides thereon; the top of the battery cell housing is provided with a clearance hole adapted to the upper end of the heat exchange plate; the bottom surface of the battery cell housing is vertically provided with an inlet pipe and an outlet pipe extending into the accommodating cavity, and both the inlet pipe and the outlet pipe are slidably and tightly in contact with the heat exchange plate.

[0008] The battery energy storage system and method of the present invention, wherein the cooling medium is perfluorohexanone liquid, a baffle is provided in the upper end of the liquid inlet pipe to seal its internal flow channel, a cooling medium flow channel port is axially provided on the upper side wall of the liquid inlet pipe, the cavities on the upper and lower sides of the baffle are connected through the cooling medium flow channel port, the axial length of the cooling medium flow channel port is greater than the longitudinal stroke of the heat exchange plate, and when assembled in place, the lower end of the cooling medium flow channel port is flush with the bottom surface of the accommodating cavity.

[0009] The battery energy storage system and method of the present invention include two parallel and opposite capacitor plates on the two inner sidewalls of the accommodating cavity along its thickness direction; a connection pin connected to the capacitor plates is provided on the upper end face of the heat exchange plate; two capacitor plates form a capacitor unit, and multiple capacitor units are provided and evenly arranged along the length direction of the heat exchange plate; when assembled, the liquid level of the cooling medium is higher than or level with the horizontal center line of the capacitor plates, so that when the heat exchange plate is subjected to the expansion and compression of the battery cells on both sides, the distance between the two capacitor plates decreases and triggers the controller to control the drive unit to drive the heat exchange plate to rise, and the battery cell shell, the accommodating cavity and the internal flow channel are all connected through the cooling medium flow channel port.

[0010] The battery energy storage system and method of the present invention include an exhaust channel communicating with the outside on the top surface of the accommodating cavity, an exhaust solenoid valve corresponding to the exhaust channel on the heat exchange plate, and both the exhaust solenoid valve and the liquid outlet pipe communicating with the heat exchange reflux mechanism.

[0011] The battery energy storage system and method of the present invention include an extension arm at the upper end of the heat exchange plate, the extension arm being longitudinally slidably connected to the outer side wall of the cell housing, and the driving unit being located on the outside of the cell housing and used to drive the extension arm to move up and down.

[0012] The battery energy storage system and method of the present invention include a supply mechanism comprising a storage tank for storing a cooling medium and a supply pump for pumping the cooling medium in the storage tank into the outlet pipe; the supply pump is electrically connected to the controller; the heat exchange reflux mechanism comprises a cooling tank for storing a low-temperature coolant and a heat exchange pipe disposed in the cooling tank; one end of the heat exchange pipe is connected to the outlet pipe and the outlet end of the exhaust solenoid valve, and the other end is connected to the storage tank.

[0013] The battery energy storage system and method of the present invention are provided with a reflux pump between the heat exchange tube, the liquid outlet tube and the solenoid valve.

[0014] Furthermore, the present invention also provides a temperature control method for a battery energy storage device, the method comprising the following steps:

[0015] Step 1: The low-temperature cooling medium in the storage tank is pumped into the accommodating cavity by the supply pump to absorb the heat dissipated by the electrical chips on both sides of the accommodating cavity, thereby reducing the internal temperature of the energy storage battery module.

[0016] Step 2: The high-temperature cooling medium in the accommodating cavity is pumped into the heat exchange tube by the reflux pump to transfer heat to the low-temperature coolant in the cooling tank, so that the cooling medium can be returned to the storage tank at a low temperature.

[0017] Step 3: The bulging of the battery chip is detected by changing the spacing between the two capacitor plates, and the controller is triggered to control the drive unit to drive the heat exchange plate to rise, so that the inner cavity of the battery cell shell, the accommodating cavity and the internal flow channel of the liquid inlet pipe are all connected through the cooling medium flow channel, so that the cooling medium flows into the heat dissipation gap.

[0018] Step 4: Circulate the cooling medium in the heat dissipation gap through the solenoid valve.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] During use, a low-temperature cooling medium is introduced into the heat exchange end through the supply mechanism to absorb the heat dissipated by the electrical chips on both sides, thereby reducing the internal core temperature of the energy storage battery module. The cooling and heat dissipation are more thorough, more efficient and better. The cooling medium that has passed through the heat exchange end can be cooled again by the heat exchange return mechanism and flow back into the supply mechanism at a low temperature for the next cycle. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is an overall structural appearance diagram of the present invention.

[0023] Figure 2 for Figure 1 A longitudinal sectional view.

[0024] Figure 3 This is a longitudinal cross-sectional view of the energy storage battery module of the present invention along its length.

[0025] Figure 4 for Figure 3 Enlarged view of the local structure shown in section A.

[0026] Figure 5 This is a side view of the heat exchange plate of the present invention.

[0027] Figure 6 This is a longitudinal cross-sectional view of the energy storage battery module of the present invention along its width direction. Detailed Implementation

[0028] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0031] Furthermore, the terms indicating orientation, such as "up," "down," "left," "right," "upper end," "lower end," and "longitudinal," are all based on the posture and position of the device or equipment described in this solution during normal use.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0033] This embodiment discloses, as follows: Figures 1 to 6 The battery energy storage system and method shown include a controller (not shown), a cabinet 10, energy storage battery modules 20 disposed within the cabinet 10, a power-off module 30 for controlling the connection and disconnection of the energy storage battery modules 20 with a load or charging power supply, and a heat dissipation system 40 for cooling the energy storage battery modules 20. Multiple energy storage battery modules 20 are arranged longitudinally in layers at the center of the cabinet 10. Further, the heat dissipation system 40 includes a liquid cooling mechanism 41 for liquid cooling of the energy storage battery modules 20, a supply mechanism 42 for supplying cooling medium to the liquid cooling mechanism 41, and a heat exchange return mechanism 43 for cooling the high-temperature cooling medium flowing through the energy storage battery modules 20 and returning it to the supply mechanism 42. Each energy storage battery module 20 includes a cell housing 21 and multiple rectangular, side-mounted battery cells 22 arranged horizontally within the cell housing 21. A heat dissipation gap 50 is provided between two adjacent electrical chips 22. The heat exchange end of the liquid cooling mechanism 41 extends into the heat dissipation gap 50 and is in contact with the electrical chips 22 on both sides, so that when the cooling medium flows through the heat exchange end, the heat of the electrical chip 22 is transferred to the cooling medium and carried away.

[0034] During use, the low-temperature cooling medium is input into the heat exchange end through the supply mechanism 42 to absorb the heat dissipated by the electric chips 22 on both sides, thereby reducing the internal core temperature of the energy storage battery module 20. The cooling and heat dissipation are more thorough, more efficient and better. The cooling medium that has passed through the heat exchange end can be cooled by the heat exchange return mechanism 43 and then flow back into the supply mechanism 42 at a low temperature for the next cycle.

[0035] In this embodiment, the liquid cooling mechanism 41 is also used to trigger the power-off module 30 to disconnect the load or charging power supply from the energy storage battery module 20. The power-off module 30 can be a conventional circuit breaker, which can execute the power-off command issued by the system after being connected to the controller. Specifically, the liquid cooling mechanism 41 includes a heat exchange plate 411 with a accommodating cavity 410 for the flow of cooling medium, and a drive unit 412 for driving the heat exchange plate 411 to rise and fall. Generally, the heat exchange plate 411 is made of copper or aluminum alloy with a thickness of 5-10 mm, while the accommodating cavity 410 has a thickness of 2-6 mm. Preferably, the heat exchange plate 411 has a thickness of 5 mm and the accommodating cavity 410 has a thickness of 3 mm. This ensures that the heat from the electrical chip 22 is transferred to the cooling medium in the accommodating cavity 410 quickly enough, ensuring timely heat exchange and preventing heat accumulation in the electrical chip 22. It also provides a certain buffer deformation space between two adjacent electrical chips 22, allowing them to compress the outer wall of the accommodating cavity 410 inwards when the electrical chip 22 bulges. Specifically, the length of the heat exchange plate 411 is greater than the length of the electrical chip 22 to ensure that the entire side surface of the electrical chip 22 can be in contact with the heat exchange plate 411, ensuring the speed and effectiveness of heat transfer.

[0036] The lower end of the heat exchange plate 411 forms the aforementioned heat exchange end and extends into the heat dissipation gap 50, fitting against the battery cells 22 on both sides of the heat dissipation gap 50 to ensure contact area and improve heat transfer efficiency. The top of the battery cell housing 21 is provided with a clearance hole 211 that matches the upper end of the heat exchange plate 411. After assembly, the inner wall of the clearance hole 211 slides tightly against the side wall of the heat exchange plate 411. The accommodating cavity 410 is rectangular and its height is less than the height of the inner cavity of the battery cell housing 21, so that its side wall can fit tightly against the inner wall of the clearance hole 211 during the upward movement of the heat exchange plate 411, preventing the upper end of the heat exchange plate 411 from being squeezed inward and deformed due to the pressure of the inner wall of the clearance hole 211. In order to ensure the sealing of the battery cell housing 21 during the longitudinal movement of the heat exchange plate 411, a sealing gasket can be provided on the side wall of the upper end of the heat exchange plate 411.

[0037] Furthermore, a liquid inlet pipe 60 and a liquid outlet pipe 70 are vertically provided on the bottom surface of the cell housing 21, extending into the accommodating cavity 410. The lower ends of both the liquid inlet pipe 60 and the liquid outlet pipe 70 protrude from the bottom of the cell housing 21 and communicate with the supply mechanism 42. The liquid inlet pipe 60 and the liquid outlet pipe 70 are located at opposite ends of the accommodating cavity 410, allowing the cooling medium to remain in the accommodating cavity 410 for a certain period of time and fully absorb the heat from the cell 22. Both the liquid inlet pipe 60 and the liquid outlet pipe 70 slide tightly against the heat exchange plate 411. Generally, a sealing sleeve is provided at the bottom of the heat exchange plate 411 to tightly fit the outer wall of the liquid inlet pipe 60 and the liquid outlet pipe 70, to prevent leakage of the cooling medium.

[0038] In this embodiment, the cooling medium is perfluorohexanone liquid. A baffle 61, sealing its internal flow channel 600, is provided at the upper end of the inlet pipe 60. A cooling medium flow port 62 is axially penetrating the upper sidewall of the inlet pipe 60. The two cavities of the internal flow channels on the upper and lower sides of the baffle 61 are connected through the cooling medium flow port 62. The axial length of the cooling medium flow port 62 is greater than the longitudinal stroke of the heat exchange plate 411. That is, the upper and lower ends of the cooling medium flow port 62 are located on the upper and lower sides of the baffle 61, respectively, preventing the cooling medium from impacting the top wall of the accommodating cavity 410 upwards. Simultaneously, it allows the cooling medium to be sprayed laterally onto the sidewall of the accommodating cavity 410 for cooling in a short time. When assembled, the lower end of the cooling medium flow port 62 is flush with the bottom surface of the accommodating cavity 410 to prevent the cooling medium in the accommodating cavity 410 from leaking from the lower end of the cooling medium flow port 62 into the inner cavity of the cell casing 21 in the initial state. Furthermore, the structure and arrangement of the liquid outlet pipe 70 are the same as those of the liquid inlet pipe 60. It is also equipped with a baffle 71 inside and a cooling medium flow channel 72 on the side wall, so as to discharge the liquid in the battery cell housing 21 and the accommodating cavity 410 in a timely manner, and avoid the risk of explosion caused by the continuous increase of pressure inside the battery cell housing 21.

[0039] In this embodiment, two parallel capacitor plates 80 are respectively provided on the two inner sidewalls of the accommodating cavity 410 along its thickness direction. The upper end face of the heat exchange plate 411 is provided with connection pins 90 for connecting the capacitor plates 80 to the controller. Furthermore, the two capacitor plates 80 form a capacitor unit, and multiple capacitor units are provided and evenly arranged along the length direction of the heat exchange plate 411 to correspond to the length of the capacitor chip 22.

[0040] When assembled, the height of the cooling medium liquid level 500 is higher than or level with the horizontal center line of the capacitor plate 80. This ensures that when the part of the heat exchange plate 411 corresponding to the accommodating cavity 410 is squeezed by the expansion and bulging of the capacitor chips 22 on both sides, the distance between the two capacitor plates 80 decreases, thereby causing a change in the output capacitance of the capacitor unit. The controller can detect the bulging situation inside the capacitor chip 22 in a timely manner through the through hole, so as to facilitate timely notification to the background management system to take corresponding response measures. This allows the management personnel to check the equipment in time or disconnect the power to isolate it, and prevent the battery from spontaneously combusting due to the continuous deterioration of the bulging and the rupture of the capacitor chip 22.

[0041] Furthermore, when the two side walls of the accommodating cavity 410 are compressed, the liquid level of the cooling medium rises simultaneously. This rise causes a change in the dielectric constant of the capacitor unit, which in turn causes a change in the output capacitance of the capacitor unit. This change, together with the aforementioned change caused by the change in spacing, provides a triggering effect for the controller, effectively ensuring the accuracy and stability of the battery bulging. The output capacitance changes twice also trigger the controller to control the drive unit 412 to drive the heat exchange plate 411 to rise, and to connect the battery cell housing 21, the accommodating cavity 410, and the internal flow channel through the cooling medium flow channel port 62. This allows the cooling medium in the outlet pipe 70 and the accommodating cavity 410 to flow into the inner cavity of the battery cell housing 21 and quickly fill the inner cavity 210 and the heat dissipation gap 50. This ensures that in the initial stage when the battery cell 22 ruptures and burns due to bulging, the cooling medium quickly enters the rupture location of the battery cell 22 and promptly blocks the combustion reaction of the battery, preventing the battery cell 22 from burning further and causing the fire to spread. This enables automatic fire extinguishing.

[0042] To further ensure sufficient cooling medium between the heat exchange plate and the battery chip, strip-shaped grooves 41a are provided on both sides of the heat exchange plate 411 for the flow and storage of cooling medium. Correspondingly, inlet pipes and outlet pipes are provided at both ends of the strip-shaped grooves and connected to them. The triggering condition of the drive unit 412 can be set by the value of the output capacitor. For example, when the output capacitance of all five capacitor units changes, the background system determines that the expansion of the battery chip 22 has reached a level sufficient to break it. The background system then disconnects the charging power supply or load through the controller power-off module 30 and controls the drive unit 412 to drive the heat exchange plate 411 to rise. This connects the accommodating cavity 410 and the inner cavity of the battery cell housing 21 through the cooling medium flow channel 62, allowing the cooling medium to quickly fill the heat dissipation gap 50 and cover the side wall of the battery chip 22. This ensures that when a crack appears in the battery chip 22, the cooling medium can enter the battery chip 22 in time to block the internal electrochemical reaction, thus suppressing thermal runaway within the battery chip and effectively preventing the battery chip from catching fire. In addition, other fire-fighting aids can be added to the cooling medium to further enhance the fire-fighting effect of the battery. Alternatively, trifluoropropane or water-based fire extinguishing agents can also be used.

[0043] In this embodiment, the top surface of the accommodating cavity 410 is provided with an exhaust channel 100 that communicates with the outside. The heat exchange plate 411 is provided with an exhaust solenoid valve 110 corresponding to the exhaust channel. The exhaust solenoid valve 110 and the liquid outlet pipe 70 are both connected to the heat exchange reflux mechanism 43. They are used to promptly discharge the floating droplets above the liquid surface after the cooling medium absorbs heat and remove the heat in the accommodating cavity 410. At the same time, they can also maintain the constant pressure in the accommodating cavity 410.

[0044] In this embodiment, the upper end of the heat exchange plate 411 is provided with an extension arm 120, which is longitudinally slidably connected to the outer wall of the cell housing 21. The drive unit 412 is located on the outside of the cell housing 21 and is used to drive the extension arm 120 to move up and down. Furthermore, a base plate 130 is provided at the bottom of the cell housing 21. The cell housing 21 and the drive unit 412 are both located on the upper surface of the base plate 130. A protective cover 131 is provided above the base plate to protect the cell housing. The liquid inlet pipe 60 and the liquid outlet pipe 70 are also located on the base plate 130 and pass through the cell housing 21 and the accommodating cavity 410 to facilitate the connection of the supply mechanism 42 and the heat exchange reflux mechanism 43 to circulate the cooling medium, and also to facilitate fixed installation.

[0045] In this embodiment, the supply mechanism 42 includes a storage tank 421 for storing cooling medium and a supply pump 422 for pumping the cooling medium from the storage tank 421 into the outlet pipe 70; the supply pump 422 is electrically connected to the controller; the heat exchange reflux mechanism 43 includes a cooling tank 431 for storing low-temperature coolant and a heat exchange tube 432 disposed in the cooling tank 431; one end of the heat exchange tube 432 is connected to the outlet pipe 70 and the outlet end of the exhaust solenoid valve 110, and the other end is connected to the storage tank 421. The cooling tank 431 is filled with coolant for heat exchange of the heat exchange tube 432, and ordinary water is generally sufficient as the coolant. Of course, the functions of the cooling tank 431 and the coolant can also be achieved by a cooling fan, which can also be used to quickly cool the heat exchange tube 432.

[0046] In this embodiment, a reflux pump 140 is provided between the heat exchange tube 432, the liquid outlet tube 70, and the solenoid valve. The reflux pump 140 is connected to the controller for easy control and to prevent the cooling medium from flowing back.

[0047] Furthermore, this embodiment also provides a temperature control method for a battery energy storage device, the method comprising the following steps:

[0048] Step 1: The low-temperature cooling medium in the storage tank 421 is pumped into the accommodating cavity 410 by the supply pump 422 to absorb the heat dissipated by the electrical chips 22 on both sides of the accommodating cavity 410, thereby reducing the internal temperature of the energy storage battery module 20.

[0049] Step 2: The high-temperature cooling medium in the accommodating cavity 410 is pumped into the heat exchange tube 432 by the return pump 140, so as to transfer heat to the low-temperature coolant in the cooling tank 431, so that the cooling medium returns to the storage tank 421 in a low-temperature state.

[0050] Step 3: The bulging detection of the battery chip 22 is achieved by changing the spacing between the two capacitor plates, and the controller is triggered to control the drive unit 412 to drive the heat exchange plate 411 to rise, so that the inner cavity of the battery cell shell 21, the accommodating cavity 410 and the internal flow channel of the liquid inlet pipe 60 are all connected through the cooling medium flow channel port 62, so that the cooling medium flows into the heat dissipation gap 50.

[0051] Step 4: Circulate the cooling medium within the heat dissipation gap 50 using a solenoid valve. It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the scope of protection of the appended claims.

Claims

1. A battery energy storage device, characterized in that, The device includes a controller, a cabinet, an energy storage battery module housed within the cabinet, a power-off module for controlling the connection and disconnection of the energy storage battery module with a load or charging power supply, and a heat dissipation system for cooling the energy storage battery module. The heat dissipation system includes a liquid cooling mechanism for liquid cooling the energy storage battery module, a supply mechanism for supplying cooling medium to the liquid cooling mechanism, and a heat exchange return mechanism for cooling the cooling medium flowing through the energy storage battery module and returning it to the supply mechanism. The energy storage battery module includes a cell housing and multiple battery cells arranged horizontally side-by-side within the cell housing. Adjacent battery cells are positioned between... Each component has a heat dissipation gap, and the heat exchange end of the liquid cooling mechanism extends into the heat dissipation gap and is in contact with the battery cells on both sides. The liquid cooling mechanism is also used to trigger the power-off module to disconnect the load or charging power supply from the energy storage battery module. The liquid cooling mechanism includes a heat exchange plate with a accommodating cavity for cooling medium flow and a drive unit for driving the heat exchange plate to rise and fall. The lower end of the heat exchange plate forms the heat exchange end and extends into the heat dissipation gap, where it is in contact with the battery cells on both sides. The top of the battery cell housing has a clearance hole adapted to the upper end of the heat exchange plate. The bottom surface of the battery cell housing has a vertically extending end into the accommodating cavity. The cavity includes an inlet pipe and an outlet pipe, both of which slide tightly against the heat exchange plate. The cooling medium is perfluorohexanone liquid. The upper end of the inlet pipe is equipped with a baffle plate that seals its internal flow channel. An axial cooling medium flow channel port is provided on the upper side wall of the inlet pipe. The cavities on the upper and lower sides of the baffle plate are connected through the cooling medium flow channel port. The axial length of the cooling medium flow channel port is greater than the longitudinal stroke of the heat exchange plate. When assembled, the lower end of the cooling medium flow channel port is flush with the bottom surface of the cavity. Two parallel and opposite capacitor plates are respectively provided on the two inner side walls of the cavity along its thickness direction. The upper end face of the heat exchange plate is provided with connection pins that connect to the capacitor plates; two capacitor plates form a capacitor unit, and multiple capacitor units are provided and evenly arranged along the length of the heat exchange plate; when assembled, the height of the cooling medium is higher than or level with the horizontal center line of the capacitor plates, so that when the heat exchange plate is subjected to the expansion and compression of the battery cells on both sides, the distance between the two capacitor plates decreases and triggers the controller to control the drive unit to drive the heat exchange plate to rise, and the battery cell shell, the accommodating cavity and the internal flow channel are all connected through the cooling medium flow channel port.

2. The battery energy storage device according to claim 1, characterized in that, The top surface of the accommodating cavity is provided with an exhaust channel communicating with the outside. The heat exchange plate is provided with an exhaust solenoid valve corresponding to the exhaust channel. Both the exhaust solenoid valve and the liquid outlet pipe are connected to the heat exchange reflux mechanism.

3. The battery energy storage device according to claim 2, characterized in that, The heat exchange plate is provided with an extension arm at its upper end. The extension arm is longitudinally slidably connected to the outer wall of the battery cell housing. The drive unit is located on the outside of the battery cell housing and is used to drive the extension arm to move up and down.

4. The battery energy storage device according to claim 3, characterized in that, The supply mechanism includes a storage tank for storing cooling medium and a supply pump for pumping the cooling medium in the storage tank into the outlet pipe; the supply pump is electrically connected to the controller; the heat exchange reflux mechanism includes a cooling tank for storing low-temperature coolant and a heat exchange tube disposed in the cooling tank; one end of the heat exchange tube is connected to the outlet pipe and the outlet end of the exhaust solenoid valve, and the other end is connected to the storage tank.

5. The battery energy storage device according to claim 4, characterized in that, A reflux pump is provided between the heat exchange tube, the liquid outlet tube, and the solenoid valve.

6. A temperature control method for a battery energy storage device, wherein the battery energy storage device according to claim 5 is characterized in that, The method includes the following steps: Step 1: The low-temperature cooling medium in the storage tank is pumped into the accommodating cavity by the supply pump to absorb the heat dissipated by the electrical chips on both sides of the accommodating cavity, thereby reducing the internal temperature of the energy storage battery module. Step 2: The high-temperature cooling medium in the accommodating cavity is pumped into the heat exchange tube by the reflux pump to transfer heat to the low-temperature coolant in the cooling tank, so that the cooling medium can be returned to the storage tank at a low temperature. Step 3: The bulging of the battery chip is detected by changing the spacing between the two capacitor plates, and the controller is triggered to control the drive unit to drive the heat exchange plate to rise, so that the inner cavity of the battery cell shell, the accommodating cavity and the internal flow channel of the liquid inlet pipe are all connected through the cooling medium flow channel, so that the cooling medium flows into the heat dissipation gap. Step 4: Circulate the cooling medium in the heat dissipation gap through the solenoid valve.

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