Flexible heat insulation structure of battery cell module, battery cell module and charge-discharge cycle testing device

Abstract

The utility model discloses a battery cell module flexible heat insulation structure, a battery cell module and a charge-discharge cycle test device, the battery cell module flexible heat insulation structure comprises: a plurality of battery cells arranged in groups; the liquid cooling plate is arranged between the adjacent battery cells, and the cooling surfaces on the two sides of the liquid cooling plate are respectively attached to the side surfaces of the corresponding battery cells; the liquid cooling plate is provided with a cooling liquid inlet flow path and a cooling liquid outlet flow path; the liquid cooling plate is made of a flexible material, and liquid cooling cavities distributed on the cross section at intervals are formed in the liquid cooling plate so as to form a cooling liquid internal flow path; a cooling liquid outlet flow path of the liquid cooling plate is provided with a pressure regulating valve, and the pressure regulating valve is used for regulating the pressure of the cooling surface of the liquid cooling plate acting on the side surface of the battery cell, so that the battery cell is in a circulating comfortable pressure state. The heat insulation structure can ensure the structural strength of the module, heat dissipation, heat insulation and circulation under constant comfortable pressure at the same time, and can improve the cycle performance of the battery cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a flexible heat insulation structure of a battery cell module. BACKGROUND

[0002] Due to excellent performance such as high voltage, high specific energy, long cycle life, etc., current lithium ion battery cells are widely used in both power batteries and energy storage batteries, and the safety problem of battery cell thermal runaway caused by mechanical, electrical and thermal abuse is particularly important.

[0003] When a certain battery cell experiences thermal runaway, a large amount of high-temperature and high-pressure gas will be generated by the internal violent reaction, and the internal space of the battery cell shell is limited. If the explosion-proof valve cannot timely discharge the generated gas, there may be a risk of explosion. However, if the shell can be deformed to some extent to increase the internal gas storage space, it will help to reduce the rapid rise of internal pressure during thermal runaway and reduce the risk of explosion. On the other hand, the high temperature of the thermal runaway battery cell will spread to the adjacent battery cells, triggering chain thermal runaway of the adjacent battery cells, and therefore, it is necessary to consider increasing the heat insulation medium between the battery cells.

[0004] Currently, when lithium ion battery cells are used in groups, the heat insulation medium between the battery cells and the battery cells generally has two forms: aerogel and liquid cooling plate.

[0005] The bearing capacity of the aerogel is relatively low, and increasing the density is an effective method to improve the strength of the aerogel, but the increase in density will also cause the deformation capacity and heat insulation performance of the material to decrease; moreover, the resilience of the aerogel may lag behind the discharge shrinkage deformation of the battery cell, causing the adhesive surface between the aerogel and the battery cell to bear tension, and there is a risk of adhesive failure and structural damage.

[0006] The liquid cooling plate generally adopts a thin-walled hollow tube made of metal, and has low compression and resilience. During the cycle process, it does not release the expansion gap for the battery cell, causing the expansion force to continuously increase, which on the one hand affects the cycle performance of the battery cell, and on the other hand may crack the liquid cooling plate, causing the cooling liquid to leak; at the same time, when the battery cell discharges and shrinks, the liquid cooling plate does not rebound, causing the adhesive surface between the liquid cooling plate and the battery cell to bear tension, and there is also a risk of adhesive failure and structural damage. CONTENT OF THE INVENTION

[0007] The purpose of the present application is to provide a flexible heat insulation structure of a battery cell module to solve the above technical problems.

[0008] Another purpose of the present application is to provide a battery cell module provided with the flexible heat insulation structure.

[0009] Still another purpose of the present application is to provide a charge and discharge cycle test device provided with the flexible heat insulation structure.

[0010] To achieve the above object, the application provides a flexible heat insulation structure of a battery cell module, comprising:

[0011] a plurality of battery cells arranged in groups along a first direction;

[0012] a liquid cooling plate arranged between adjacent battery cells in the first direction, the cooling surfaces on both sides of the liquid cooling plate being respectively attached to the side surfaces of the corresponding battery cells; the liquid cooling plate is provided with a cooling liquid inlet flow path and a cooling liquid outlet flow path;

[0013] The liquid cooling plate is a flexible material liquid cooling plate, and the inside of the liquid cooling plate is provided with liquid cooling cavities spaced apart along a second direction in the cross section, the liquid cooling cavities forming an internal cooling liquid flow path; the cooling liquid inlet flow path and / or the cooling liquid outlet flow path of the liquid cooling plate is provided with a pressure regulating valve, the pressure regulating valve being used to adjust the pressure of the cooling surface of the liquid cooling plate acting on the side surface of the battery cell, so that the battery cell is in a cyclic comfortable pressure state.

[0014] Optionally, a plurality of liquid cooling plates are included, the cooling liquid inlet flow paths of the liquid cooling plates are combined into an inlet flow path, the inlet flow path is provided with the pressure regulating valve, and / or the cooling liquid outlet flow paths of the liquid cooling plates are combined into an outlet flow path, the outlet flow path is provided with the pressure regulating valve, so as to simultaneously adjust the cooling liquid pressure inside the liquid cooling plate.

[0015] Optionally, a plurality of liquid cooling plates are included, the liquid cooling plates are divided into groups, the cooling liquid inlet flow paths of the liquid cooling plates in each group are combined into an inlet flow path, the inlet flow path is provided with the pressure regulating valve, and / or the cooling liquid outlet flow paths of the liquid cooling plates in each group are combined into an outlet flow path, each flow path is provided with the pressure regulating valve, so as to adjust the cooling liquid pressure inside the liquid cooling plate in groups.

[0016] Optionally, a plurality of liquid cooling plates are included, the cooling liquid inlet flow paths and / or the cooling liquid outlet flow paths of the liquid cooling plates are respectively provided with the pressure regulating valve, so as to respectively adjust the cooling liquid pressure inside each liquid cooling plate.

[0017] Optionally, the inside of the liquid cooling plate is provided with a layer of liquid cooling cavities spaced apart along the second direction in the cross section, or the inside of the liquid cooling plate is provided with at least two layers of liquid cooling cavities spaced apart along the second direction in the cross section.

[0018] Optionally, the liquid cooling cavities in two adjacent layers are distributed in a staggered manner along the second direction in the cross section of the battery cell.

[0019] Optionally, in the cross section of the liquid cooling plate, the length of the liquid cooling cavities gradually increases in the order from both ends to the middle.

[0020] Optionally, the pressure regulating range of the pressure regulating valve covers (F0 / A, Fmax / A), wherein F0 is the initial pre-tightening force of the cell, Fmax is the maximum cyclic swelling force of the cell at EOL, and A is the area of the side surface of the cell.

[0021] To achieve the above-mentioned another object, the application provides a cell module with a cell module flexible heat insulation structure, which is any one of the above-mentioned cell module flexible heat insulation structures.

[0022] To achieve the above-mentioned another object, the application provides a charge-discharge cycle test device, which comprises a cell module flexible heat insulation structure, which is any one of the above-mentioned cell module flexible heat insulation structures.

[0023] The cell module flexible heat insulation structure provided by the application is arranged between the side surfaces of the cells arranged in groups and comprises a liquid cooling plate made of flexible material. The inlet flow path of the liquid cooling plate can be connected to the cooling liquid flowing from the whole vehicle system, and the cooling and heat dissipation capacity of the flexible liquid cooling plate is relied on to realize the heat insulation between the cells. Since the outlet flow path is provided with a pressure regulating valve, the cooling liquid in the liquid cooling plate can maintain a constant pressure under the action of the pressure regulating valve. The pressure regulating valve can not only ensure the overall bearing capacity of the cells arranged in groups and realize the circulation of the cells under a comfortable pressure to improve the cycle performance, but also keep the compression and rebound deformation of the flexible liquid cooling plate consistent with the charging expansion and discharging shrinkage deformation of the cells during use. In this way, the cooling surface of the liquid cooling plate can be perfectly matched with the side surface of the cell, and there is no hysteresis, which improves the cooling and heat dissipation efficiency and further improves the heat insulation capacity.

[0024] The cell module and the charge-discharge cycle test device provided by the application are provided with the cell module flexible heat insulation structure. Since the cell module flexible heat insulation structure has the above-mentioned technical effects, the cell module and the charge-discharge cycle test device provided with the cell module flexible heat insulation structure should also have corresponding technical effects. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The axial side view of the cell module flexible heat insulation structure provided by the first embodiment of the application;

[0026] Figure 2 The axial side view of the cell module flexible heat insulation structure provided by the first embodiment of the application; Figure 1 The cross-sectional view of the cell module flexible heat insulation structure shown in the first embodiment of the application;

[0027] Figure 3 The structure schematic view of the liquid cooling cavity of the liquid cooling plate in the cross section in the form of an ellipse;

[0028] Figure 4 The structure schematic view of the liquid cooling cavity of the liquid cooling plate in the cross section in the form of a rectangle;

[0029] Figure 5 Structure diagram of liquid cooling cavity of liquid cooling plate in cross section;

[0030] Figure 6 Structure diagram of liquid cooling plate with two layers of liquid cooling cavities in cross section;

[0031] Figure 7 Structure diagram of liquid cooling plate with three layers of liquid cooling cavities in cross section and staggered distribution;

[0032] Figure 8 Structure diagram of liquid cooling cavity of liquid cooling plate in cross section with gradually increasing length from both ends to the middle;

[0033] Figure 9 Structure diagram of liquid cooling plate with pressure regulating valve arranged in cooling liquid outlet flow path of each liquid cooling plate;

[0034] Figure 10 Structure diagram of liquid cooling plate with pressure regulating valve arranged in cooling liquid outlet flow path after merging into a common flow path;

[0035] Figure 11 Structure diagram of liquid cooling plate with pressure regulating valve arranged in cooling liquid outlet flow path in groups;

[0036] Figure 12 Structure diagram of liquid cooling plate with parallel flow path for cooling liquid internal flow path;

[0037] Figure 13 Structure diagram of liquid cooling plate with S-shaped flow path for cooling liquid internal flow path.

[0038] In the drawings:

[0039] 10 - battery cell; 20 - liquid cooling plate; 21 - liquid cooling cavity; 22 - cooling liquid inlet flow path; 23 - cooling liquid outlet flow path; 24 - liquid inlet header; 25 - liquid outlet header; 30 - pressure regulating valve. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present application, the present application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0041] In this document, the terms "upper", "lower", "inner", "outer" and the like are established based on the positional relationship shown in the drawings, and according to different drawings, the corresponding positional relationship may also change accordingly, therefore, it cannot be understood as an absolute limitation on the scope of protection; moreover, such as "first" and "second" and the like, the relationship terms are only used to distinguish one part from another part with the same name, and do not necessarily require or imply any such actual relationship or order between the parts.

[0042] Please refer to Figure 1 、 Figure 2 , Figure 1 The axial side view of the flexible thermal insulation structure of the battery cell module provided in the first embodiment of the present application is shown in the figure. Figure 2 The cross-sectional view of the flexible thermal insulation structure of the battery cell module is shown in the figure. Figure 1

[0043] As shown in the figure, in a specific embodiment, the flexible thermal insulation structure of the battery cell module provided in the present application is mainly composed of battery cells 10 and liquid cooling plates 20, etc. The number of battery cells 10 is multiple, and the multiple battery cells 10 are arranged in groups along a first direction, i.e. the X direction shown in the coordinate system, and a certain spacing is left between the battery cells 10 to place the liquid cooling plates 20. For the sake of simplicity, only three battery cells 10 and two liquid cooling plates 20 are shown in the figure. Figure 1

[0044] A liquid cooling plate 20 is arranged between two adjacent battery cells 10 in the first direction. The liquid cooling plate 20 is generally in a flat plate structure, and has a large area on both sides to form cooling surfaces. The cooling surfaces on both sides are respectively attached to the side surfaces of the battery cells 10 on the corresponding side to exchange heat through the face-to-face contact, so as to achieve the purpose of cooling the battery cells.

[0045] The liquid cooling plate 20 is a flexible material liquid cooling plate, and has liquid cooling cavities 21 spaced apart in a second direction in the cross section to form the internal flow path of the cooling liquid. The internal flow path of the cooling liquid can be a parallel flow path as shown in the figure, an S-shaped flow path as shown in the figure, or other forms of flow paths. The second direction is the Z direction shown in the coordinate system. When a certain battery cell 10 is in thermal runaway, the cooling effect of the liquid cooling plate 20 can timely take away the heat of the battery cell 10 to avoid spreading to the adjacent battery cells 10, thereby achieving the effect of thermal insulation. Figure 12 Figure 13 Figure 1

[0046] The liquid cooling plate 20 is provided with a cooling liquid inlet flow path 22 and a cooling liquid outlet flow path 23. In the present embodiment, the cooling liquid inlet flow path 22 is provided with a liquid inlet header tank 24 on one side, and the cooling liquid outlet flow path 23 is provided with a liquid outlet header tank 25 on one side. The downstream of the liquid outlet header tank 25 forms an outlet flow path, and a pressure regulating valve 30 is arranged on the outlet flow path. The pressure regulating valve 30 is used to adjust the pressure of the cooling surface of the liquid cooling plate 20 acting on the side surface of the battery cell 10, so that the battery cell 10 is in a cyclic comfortable pressure state.

[0047] The liquid inlet header tank 24 of the liquid cooling plate 20 can be connected to the cooling system of the whole vehicle, and the liquid outlet header tank 25 returns to the cooling system through the pressure regulating valve 30 to realize the circulation of the cooling liquid.

[0048] ​​​​​The material of the liquid cooling plate 20 can be silicone, PVC (polyvinyl chloride plastic), rubber, or SMC (Sheet Molding Compound, a kind of sheet molding material made by impregnating resin paste into fibers or chopped fiber mat covered with polyethylene film on both sides), or other similar flexible materials. Such materials have high strength, and under the action of the outlet pressure regulating valve 30, the cooling liquid inside the liquid cooling plate 20 can maintain a certain pressure, ensuring the overall load capacity after grouping. The flexible liquid cooling plate deforms and rebounds by internal liquid flow at room temperature and low temperature. Since the pressure is constant, there is no hysteresis.

[0049] According to the initial pre-tightening force F0 and the maximum cyclic expansion force Fmax of the battery cell, the pressure regulating range (F0 / A, Fmax / A) of the pressure regulating valve 30 can be determined, where F0 is the initial pre-tightening force of the battery cell, Fmax is the maximum cyclic expansion force of the battery cell at EOL, and A is the area of the side surface of the battery cell, i.e. the large surface area. Assuming that the comfortable pressure of the battery cell during cycling (i.e. the force most conducive to cycling performance) is F, the pressure of the pressure regulating valve can be set to F / A. Under this pressure, the battery cell 10 can be ensured to cycle within the comfortable pressure range throughout its life cycle, which is conducive to the cycling performance.

[0050] Note: EOL, an abbreviation of End of Life or End of Service, has a specific meaning in the battery field, which means that the battery has undergone the complete charge and discharge cycle set by the manufacturer, or its performance has declined to the point where it cannot meet the use requirements, and it needs to be replaced. Once the battery enters the EOL state, it means that it is difficult to provide enough power for the device, and a new battery must be replaced. Although the EOL battery may still work, its performance has been greatly reduced and needs to be replaced in time.

[0051] When the outlet pressure is set through the pressure regulating valve 30, the flexible liquid cooling plate 20 can provide a support force F = P * A, where P is the set outlet pressure and A is the contact area between the liquid cooling plate 20 and the battery cell 10 shell. The value of P can be adjusted and kept constant by the pressure regulating valve 30, and the value of A is the large surface area of the battery cell 10 shell. Therefore, F remains constant throughout the cycling process, and a suitable constant force is more conducive to battery cycling.

[0052] Of course, the P calculated according to F = P * A is not an absolute value, and in actual adjustment, the pressure regulating valve 30 is allowed to have a reasonable range of error.

[0053] Thus, the compression and rebound deformation of the flexible liquid cooling plate 20 can be consistent with the charging expansion and discharging shrinkage deformation of the battery cell 10, so as to realize the ideal adhesion of the cooling surface of the liquid cooling plate 20 to the side surface of the battery cell 10, improve the cooling and heat dissipation efficiency, and further improve the heat insulation capacity.

[0054] As shown in Figure 2 , when the battery cell 10 is charged and expanded, the flexible liquid cooling plate 20 is deformed by being pressed, and the deformation of the liquid cooling plate 20 is completely consistent with the expansion deformation of the battery cell 10, which is beneficial to the cooling and heat dissipation of the battery cell 10. When the battery cell 10 is discharged and shrinks, the flexible liquid cooling plate 20 rebounds under the action of the internal pressure, and still maintains the adhesion to the large surface of the battery cell 10, and there is no problem of rebound hysteresis. Since the internal pressure of the flexible liquid cooling plate 20 is consistent with the outlet pressure, it can always remain constant, so that the battery cell 10 is always in the cycle comfort pressure range regardless of the expansion state, which is beneficial to the best cycle performance of the battery cell.

[0055] Please refer to Figure 9 , Figure 9 for the structure schematic diagram of the cooling liquid outlet flow path of each liquid cooling plate.

[0056] As shown in the figure, compared with the first embodiment, the difference of the present embodiment is that:

[0057] The cooling liquid outlet flow path 23 of each liquid cooling plate 20 is respectively provided with a pressure regulating valve 30, so that the cooling liquid pressure in each liquid cooling plate 20 can be adjusted respectively, and the pressure of the cooling surface of the liquid cooling plate 20 acting on the side surface of the battery cell 10 is adapted to the cycle comfort pressure F of the battery cell 10.

[0058] By adopting this structure form, the pressure of each liquid cooling plate 20 acting on the side surface of the battery cell 10 can be independently adjusted, so that in the case that the cycle comfort pressure F of the battery cell 10 exists difference, the flexibility of the pressure adjustment of the liquid cooling plate can be improved.

[0059] In the present embodiment, the same parts as in the first embodiment are given the same reference numerals, and the same textual description is omitted.

[0060] Please refer to Figure 10 , Figure 10 for the structure schematic diagram of the cooling liquid outlet flow path of each liquid cooling plate.

[0061] As shown in the figure, compared with the first embodiment, the difference of the present embodiment is that:

[0062] The cooling liquid outlet flow paths 23 of the liquid cooling plates 20 are all merged into the same outlet flow path, and the outlet flow path is provided with a pressure regulating valve 30, so that the cooling liquid pressure inside all the liquid cooling plates 20 can be simultaneously regulated, and the pressure of the cooling surface of the liquid cooling plates 20 acting on the side surface of the battery cell 10 is adapted to the circulating comfortable pressure of the battery cell 10.

[0063] This structure only needs to use a small number of pressure regulating valves 30 to regulate the pressure of the liquid cooling plates, and can simultaneously regulate all the liquid cooling plates 20 to keep the pressure consistent, which is simple in structure and convenient in layout, and is more suitable for the case where the circulating comfortable pressures F of the battery cells 10 are not greatly different.

[0064] In this embodiment, the same parts as in the first embodiment are given the same reference numerals, and the same textual description is omitted.

[0065] Please continue to refer to Figure 11 , Figure 11 The structure schematic view of the pressure regulating valve provided for the cooling liquid outlet flow path of the liquid cooling plate.

[0066] As shown in the figure, the difference between this embodiment and the first embodiment is that:

[0067] The liquid cooling plates 20 are divided into multiple groups, and the cooling liquid outlet flow paths 23 of three liquid cooling plates 20 in each group are merged into an outlet flow path, and each outlet flow path is provided with a pressure regulating valve 30, so that the cooling liquid pressure inside the liquid cooling plates 20 can be regulated in groups, and the pressure of the cooling surface of the liquid cooling plates 20 acting on the side surface of the battery cell 10 is adapted to the circulating comfortable pressure of the battery cell 10.

[0068] This group pressure regulating structure form combines the advantages of the Figure 9 , Figure 10 embodiments shown in the figures, and the number of pressure regulating valves 30 used is reasonable, and each pressure regulating valve 30 can regulate the pressure of multiple liquid cooling plates 20, and a better balance between structural complexity and control flexibility can be achieved.

[0069] In this embodiment, the same parts as in the first embodiment are given the same reference numerals, and the same textual description is omitted.

[0070] The above embodiments are only preferred solutions of the present application, and are not limited thereto, and targeted adjustments can be made according to actual needs to obtain different embodiments.

[0071] For example, the liquid cooling cavity 21 of the liquid cooling plate 20 is in the shape of an ellipse (see Figure 3 ), a rectangle (see Figure 4 ), or a circle (see Figure 5etc., wherein the circular liquid cooling cavity 21 can form more flow channels, thereby improving heat dissipation efficiency and being easy to process and form, the elliptical liquid cooling cavity 21 is more likely to elastically deform when being extruded, thereby better adapting to the deformation of the battery cell 10, and the rectangular liquid cooling cavity 21 has a larger heat dissipation contact area, thereby facilitating the improvement of heat dissipation efficiency and also having the characteristics of being easy to elastically deform to adapt to the deformation of the battery cell 10.

[0072] Alternatively, the liquid cooling plate 20 is internally provided with two layers of liquid cooling cavities 21 spaced apart along the second direction in the cross section (see Figure 6 ), or, the liquid cooling plate 20 is internally provided with three layers of liquid cooling cavities 21 spaced apart along the second direction in the cross section, and the adjacent two layers of liquid cooling cavities 21 are distributed in a staggered manner along the second direction of the cross section of the battery cell (see Figure 7 By designing two layers of liquid cooling cavities 21 or three layers of staggered liquid cooling cavities 21, on the one hand, the structural strength and support performance of the liquid cooling plate 20 can be improved, and on the other hand, in the case that one of the liquid cooling cavities 21 cannot work normally, the remaining liquid cooling cavities 21 can still play a cooling and heat dissipation role, ensuring that the entire liquid cooling plate 20 does not completely fail.

[0073] In addition, in the cross section of the liquid cooling plate 20, the length of the liquid cooling cavity 21 can gradually increase in the order from both ends to the middle (see Figure 8 ) to adapt to the characteristics of the middle part of the battery cell 10 expanding and deforming more.

[0074] In addition, the pressure regulating valve 30 can also be arranged at the cooling liquid inlet flow path 22 of each liquid cooling plate, or the cooling liquid inlet flow path 22 and the cooling liquid outlet flow path 23 of each liquid cooling plate 20 are respectively provided with a pressure regulating valve 30, and the pressure in the liquid cooling plate 20 is adjusted through the cooperative matching of the two pressure regulating valves 30.

[0075] Similarly, if the cooling liquid inlet flow path 22 of the liquid cooling plate 20 is combined into an inlet merging flow path, for example, the inlet merging flow path is formed upstream of the liquid inlet header 24, the pressure regulating valve 30 can also be arranged on the inlet merging flow path, or the pressure regulating valve 30 is arranged on the inlet merging flow path and the outlet merging flow path at the same time, and the pressure in the liquid cooling plate 20 is adjusted through the cooperative matching of the two pressure regulating valves 30.

[0076] Moreover, the above structures can be combined without contradiction, etc. Since there are many possible ways, they will not be illustrated one by one here.

[0077] The battery cell module flexible heat insulation structure provided in the present application can not change the existing module form, nor need to additionally increase structural members, can simultaneously realize the guarantee of the module structural strength, heat dissipation and heat insulation, circulation under constant comfortable pressure, can improve the battery cell circulation performance, and reduce the risk of thermal runaway explosion and thermal runaway spread.

[0078] In addition to the flexible heat insulation structure of the battery cell module described above, the application also provides a battery cell module having the flexible heat insulation structure of the battery cell module, and the flexible heat insulation structure of the battery cell module is the flexible heat insulation structure of the battery cell module described above, and the remaining structure of the battery cell module will not be described herein.

[0079] As an extended application, the flexible heat insulation structure of the battery cell module described above can also be used in a charge-discharge cycle test device, that is, the metal rigid liquid cooling plate is replaced by the flexible liquid cooling plate in the cycle test tooling, and according to P=F / A, the outlet pressure P is set, so that the battery cell can be cycled under the comfortable pressure, and the cycle test performance is improved.

[0080] The flexible heat insulation structure of the battery cell module, the battery cell module and the charge-discharge cycle test device provided by the application are described in detail above. The principles and implementation modes of the application are described by applying specific examples, and the above description of the examples is only used to help understand the core idea of the application. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the application without departing from the principles of the application, and these improvements and modifications also fall within the protection scope of the claims of the application.

Claims

1. Flexible thermal insulation structure for battery cell modules, including: A battery cell (10), wherein a plurality of said battery cells (10) are arranged in a group along a first direction; A liquid cooling plate (20) is provided between adjacent cells (10) in the first direction. The cooling surfaces on both sides of the liquid cooling plate (20) are respectively attached to the sides of the corresponding cells (10). The liquid cooling plate (20) is provided with a coolant inlet flow path (22) and a coolant outlet flow path (23). The liquid cooling plate (20) is a flexible liquid cooling plate with liquid cooling cavities (21) spaced apart along the second direction in its cross-section. The liquid cooling cavities (21) form an internal flow path for the coolant. The coolant inlet flow path (22) and / or the coolant outlet flow path (23) of the liquid cooling plate (20) are provided with pressure regulating valves (30). The pressure regulating valves (30) are used to adjust the pressure exerted by the cooling surface of the liquid cooling plate (20) on the side of the battery cell (10) so that the battery cell (10) is in a comfortable circulating pressure state.

2. The flexible thermal insulation structure for the battery cell module according to claim 1, characterized in that, The system includes multiple liquid cooling plates (20), the coolant inlet flow path (22) of each liquid cooling plate (20) is merged into an inlet manifold flow path, the inlet manifold flow path is provided with the pressure regulating valve (30), and / or, the coolant outlet flow path (23) of each liquid cooling plate (20) is merged into an outlet manifold flow path, the outlet manifold flow path is provided with the pressure regulating valve (30) to simultaneously regulate the cooling pressure inside the liquid cooling plate (20).

3. The flexible thermal insulation structure for the battery cell module according to claim 1, characterized in that, The system includes multiple liquid cooling plates (20), which are divided into multiple groups. The coolant inlet flow path (22) of each group of liquid cooling plates (20) is merged into an inlet manifold flow path. Each inlet manifold flow path is equipped with a pressure regulating valve (30). Alternatively, the coolant outlet flow path (23) of each group of liquid cooling plates (20) is merged into an outlet manifold flow path. Each outlet manifold flow path is equipped with a pressure regulating valve (30) to adjust the cooling pressure inside the liquid cooling plates (20) in groups.

4. The flexible thermal insulation structure for the battery cell module according to claim 1, characterized in that, The system includes multiple liquid cooling plates (20), and each liquid cooling plate (20) is provided with a pressure regulating valve (30) in the coolant inlet flow path (22) and / or the coolant outlet flow path (23) to adjust the cooling pressure inside each liquid cooling plate (20).

5. The flexible thermal insulation structure for the battery cell module according to claim 1, characterized in that, The liquid cooling plate (20) has a layer of liquid cooling cavities (21) spaced apart along the second direction in the cross-section, or the liquid cooling plate (20) has at least two layers of liquid cooling cavities (21) spaced apart along the second direction in the cross-section.

6. The flexible thermal insulation structure for the battery cell module according to claim 5, characterized in that, The liquid cooling cavities (21) of the two adjacent layers are staggered along the second direction on the cross-section of the cell (10).

7. The flexible thermal insulation structure for the battery cell module according to claim 5, characterized in that, On the cross-section of the liquid cooling plate (20), the length of the liquid cooling cavity (21) gradually increases from both ends to the middle.

8. The flexible thermal insulation structure for the battery cell module according to any one of claims 1 to 7, characterized in that, The pressure regulating valve (30) has a pressure regulating range covering (F0 / A, Fmax / A), where F0 is the initial preload of the battery cell, Fmax is the maximum cyclic expansion force of the battery cell at EOL, and A is the area of ​​the side of the battery cell.

9. A battery cell module, characterized in that, a flexible heat insulation structure for the battery cell module is provided. The flexible thermal insulation structure of the battery cell module is the flexible thermal insulation structure of the battery cell module as described in any one of claims 1 to 8.

10. A charge-discharge cycle testing device, comprising a flexible heat-insulating structure for battery cell modules, characterized in that, The flexible thermal insulation structure of the battery cell module is the flexible thermal insulation structure of the battery cell module as described in any one of claims 1 to 8.

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