An immersed liquid-cooled lithium battery module

Abstract

This invention discloses an immersion-type liquid-cooled lithium battery module. The invention includes cylindrical battery cells, a module housing, a coolant inlet, a first coolant outlet, and a second coolant outlet. In the radial direction of the module, the cylindrical battery cells are closely arranged around the center of the module housing, with adjacent battery cells being tangent to each other. In the axial direction of the module, the battery cells are connected in series. The coolant inlet is located at the center of the top of the module and is used to inject coolant at a certain flow rate. The first and second coolant outlets are located at the top of the module and are used to discharge the coolant. This invention can achieve rapid heat dissipation from the cylindrical lithium battery, and the cylindrical housing structure allows for a compact arrangement of the lithium batteries, ensuring that the maximum temperature difference between battery cells does not exceed 3°C.

Description

Technical Field

[0001] This invention relates to the field of electrochemical new energy technology, and more specifically, to an immersion liquid-cooled lithium battery module. Background Technology

[0002] Lithium-ion batteries are widely used in power and energy storage fields due to their high energy density, high operating voltage, high output power, long charge-discharge cycle life, low self-heating rate, and green safety and environmental friendliness. However, batteries generate heat during use, and if this heat accumulates inside the battery, it can easily lead to thermal runaway, causing serious safety accidents. Therefore, thermal management technology is particularly important in the design of lithium-ion battery modules.

[0003] Currently, battery cooling technologies mainly include air cooling, liquid cooling plates, and phase change materials. These technologies can achieve battery cooling to a certain extent, but with the increasing demands for battery capacity and charging speed, technologies with better thermal conductivity are needed. Direct liquid cooling technology, as an emerging technology, has the advantages of high thermal conductivity and high safety. The lithium battery cells are directly immersed in the coolant, which increases the contact area between the liquid and the cells. Moreover, even if thermal runaway occurs, the coolant can act as the first line of defense to reduce the risk of an accident.

[0004] Although patents CN117497938A, CN116315288A, CN117199607A, CN117335051A, CN116487755A, CN219832789U, and CN218472082U disclose a number of immersion-type lithium battery modules or systems, these all target pouch or hard-shell batteries and do not involve cylindrical batteries. Furthermore, existing technologies only address the overall structure of the liquid cooling system and do not design the cooling channel structure inside the module, making it impossible to achieve a temperature difference of less than 5°C between individual battery cells. Therefore, it is necessary to develop an immersion-type liquid-cooled module structure suitable for cylindrical lithium batteries and design the flow channel structure within each module to achieve rapid battery cooling while ensuring that the maximum temperature difference between individual battery cells does not exceed 3°C. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an immersion liquid-cooled lithium battery module with high heat exchange efficiency and high safety.

[0006] The present invention includes cylindrical battery cells, a module housing, a coolant inlet, a first coolant outlet, and a second coolant outlet; in the radial direction of the module, the cylindrical battery cells are closely arranged around the center of the module housing, and adjacent battery cells are tangent to each other; in the axial direction of the module, the battery cells are connected in series.

[0007] The coolant inlet is located at the center of the top of the module and is used to inject coolant at a certain flow rate;

[0008] The first coolant outlet and the second coolant outlet are located at the top of the module and are used to discharge the coolant.

[0009] The beneficial effects of this invention are:

[0010] The lithium battery module designed in this invention enables rapid heat dissipation from cylindrical lithium batteries. The cylindrical casing allows for a compact arrangement of the lithium batteries, ensuring a maximum temperature difference of no more than 3°C between individual cells. Coolant flows in from the center of the module, allowing the low-temperature liquid to remove more heat. A guide cone at the bottom of the module prevents direct impact on the bottom and guides the fluid towards the vicinity of the module walls. A rectifier within the module enhances the mixing effect of the coolant near the walls, promoting heat exchange between the battery and the coolant.

[0011] Furthermore, the coolant used in this invention is a non-flammable liquid, which can serve as the first line of defense against the spread of danger in the event of battery runaway. Therefore, this invention is a highly efficient and safe lithium battery module that can be widely applied in power batteries and energy storage. Attached Figure Description

[0012] Figure 1 This is an axial cross-sectional view of an immersed liquid-cooled lithium battery module according to an embodiment of the present invention;

[0013] Figure 2 This is a radial cross-sectional view of an immersion liquid-cooled lithium battery module according to an embodiment of the present invention;

[0014] Figure 3 This is a simulation diagram of the temperature difference between individual battery cells in Example 1;

[0015] Figure 4 This is a simulation diagram of the temperature difference between individual battery cells in Example 2;

[0016] Figure 5 This is a simulation diagram of the temperature difference between individual battery cells in Example 3. Detailed Implementation

[0017] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] This application discloses an immersion liquid-cooled lithium battery module, comprising the following structures: a cylindrical battery cell, a module housing, a coolant inlet, a first coolant outlet, a second coolant outlet, a rectifier, a flow guide cone, and a separator.

[0019] In the radial direction of the module, cylindrical battery cells are closely arranged around the center of the module housing, with adjacent cells being tangent to each other and the center of the circle formed by the cells coinciding with the center of the module.

[0020] The individual modules are connected in series along the axial direction of the module. The coolant inlet is located at the center of the top of the module and is used to inject coolant at a certain flow rate.

[0021] The coolant outlet is located at the center of the top of the module and is used to discharge coolant.

[0022] The guide cone is located at the center of the bottom of the module and is used to change the flow direction of the coolant.

[0023] The rectifier is located on the inner wall of the module housing to promote coolant mixing. The baffle is installed between the top of the battery cell and the top of the module to separate the coolant inlet and outlet channels.

[0024] Furthermore, the housing size of the module and the number of battery cells arranged tangentially in the axial direction need to be determined according to the module capacity requirements.

[0025] Furthermore, the distance between the battery cell of the module and the top and bottom of the module is 0.1r to r, and preferably 0.2r to 0.8r to ensure smooth fluid flow at the top and bottom, where r is the diameter of the battery cell.

[0026] Furthermore, the distance between the coolant outlet of the module and the center of the module is 0.1R to 0.9R. In order to ensure the residence time of the fluid in the module, it is preferably 0.5R to 0.8R, where R is the radius of the module cross-section.

[0027] Furthermore, the coolant inlet diameter of the module is 0.1r to 2r, and preferably 0.2r to 1.5r to ensure the flow rate of the inlet fluid, where r is the diameter of the battery cell.

[0028] Furthermore, the coolant outlet diameter of the module is 0.05R to 0.5R, and preferably 0.05R to 0.3R to ensure the flow rate of the outlet fluid, where R is the radius of the module's cross-section.

[0029] Furthermore, the rectifiers of the module are triangular prisms, evenly distributed in the circumferential and axial directions of the module, with 2 to 10 rectifiers arranged in the circumferential direction and 3 to 10 rectifiers arranged in the axial direction.

[0030] Furthermore, the flow guide cone of the module is conical with a apex angle of 10° to 150°. In order to reduce the resistance of the fluid changing direction after reaching the bottom of the module, it is preferably 45° to 120°. The bottom diameter is 0.1r to 3r, preferably 0.5r to 2r, where r is the diameter of the battery cell.

[0031] Furthermore, the coolant used in the module is a liquid with good thermal conductivity and flame retardancy. In order to ensure a good cooling effect, a fluorinated liquid is preferred.

[0032] Furthermore, the flow rate of each coolant inlet of the module is 1 to 10 L / min, and preferably 2 to 5 L / min for better heat dissipation capability.

[0033] Example 1:

[0034] This embodiment includes: a cylindrical battery cell 1, a module housing 2, a coolant inlet 3, a first coolant outlet 4, a second coolant outlet 5, a rectifier 6, a flow guide cone 7, and a separator 8.

[0035] In this embodiment, cylindrical battery cells are arranged closely around the center of the module housing in the circumferential direction of the module. Adjacent cells are tangent to each other and the center of the circle formed by the cells coincides with the center of the module.

[0036] The individual cells are connected in series along the module's height. The coolant inlet is located at the center of the top of the module, for injecting coolant at a controlled flow rate. The coolant outlet is also located at the center of the top of the module, for discharging coolant. A guide cone is located at the center of the bottom of the module, for changing the direction of coolant flow. A rectifier is located on the inner wall of the module housing, for promoting coolant mixing. A baffle is installed between the top of the individual cells and the top of the module, for separating the coolant inlet and outlet channels.

[0037] Furthermore, the module contains 15 4680 cylindrical battery cells connected in series. The diameter and height of each cell are 46cm and 80cm, respectively, and the module diameter is 156.4cm.

[0038] Furthermore, the distances between the individual battery cells and the top and bottom of the module are 10cm and 20cm, respectively.

[0039] Furthermore, the distance between the two coolant outlets of the module and the center of the module is 39.1 cm.

[0040] Furthermore, the coolant inlet diameter is 20cm.

[0041] Furthermore, the coolant outlet diameter is 10cm.

[0042] Furthermore, the angle between the coolant outlet 1 and coolant outlet 2 of the module and the center of the module is 180°.

[0043] Furthermore, the rectifiers of the module are regular triangular prisms with a side length of 4.6cm and a thickness of 10cm. They are evenly distributed in the circumferential and axial directions of the module, with 5 rectifiers arranged in the circumferential direction and 6 rectifiers arranged in the axial direction.

[0044] Furthermore, the module's guide cone is conical with a apex angle of 120° and a bottom diameter of 46cm.

[0045] Furthermore, the coolant used in the module is a fluorinated liquid.

[0046] Furthermore, the flow rate at each coolant inlet is 1.4 L / min.

[0047] This embodiment was simulated using COMSL simulation software. When each battery cell was charged at 0.5C, the temperature difference between the battery cells within the module was 0.4℃. The simulation results are as follows: Figure 3 As shown, this demonstrates that the immersion module of this structure has a very good cooling effect.

[0048] Example 2:

[0049] This embodiment includes a cylindrical battery cell 1, a module housing 2, a coolant inlet 3, a first coolant outlet 4, a second coolant outlet 5, a rectifier 6, a flow guide cone 7, and a separator 8.

[0050] In this embodiment, cylindrical battery cells are arranged closely around the center of the module housing on the module's circumference, with adjacent cells being tangent to each other and the center of the circle formed by the cells coinciding with the center of the module.

[0051] The individual cells are connected in series along the module's height. The coolant inlet is located at the center of the top of the module, for injecting coolant at a controlled flow rate. The coolant outlet is also located at the center of the top of the module, for discharging coolant. A guide cone is located at the center of the bottom of the module, for changing the direction of coolant flow. A rectifier is located on the inner wall of the module housing, for promoting coolant mixing. A baffle is installed between the top of the individual cells and the top of the module, for separating the coolant inlet and outlet channels.

[0052] Furthermore, the module contains 15 4680 cylindrical battery cells connected in series. The diameter and height of each cell are 46cm and 80cm, respectively, and the module diameter is 156.4cm.

[0053] Furthermore, the distances between the individual battery cells and the top and bottom of the module are 10cm and 20cm, respectively.

[0054] Furthermore, the distance between the two coolant outlets of the module and the center of the module is 39.1 cm.

[0055] Furthermore, the coolant inlet diameter is 20cm.

[0056] Furthermore, the coolant outlet diameter is 10cm.

[0057] Furthermore, the angle between the coolant outlet 1 and coolant outlet 2 of the module and the center of the module is 180°.

[0058] Furthermore, the rectifiers of the module are regular triangular prisms with a side length of 4.6cm and a thickness of 10cm. They are evenly distributed in the circumferential and axial directions of the module, with 5 rectifiers arranged in the circumferential direction and 6 rectifiers arranged in the axial direction.

[0059] Furthermore, the module's guide cone is conical with a apex angle of 120° and a bottom diameter of 46cm.

[0060] Furthermore, the coolant used in the module is a fluorinated liquid.

[0061] Furthermore, the flow rate at each coolant inlet is 1.4 L / min.

[0062] The COMSL simulation software was used to simulate this embodiment. When each battery cell was charged at 2C, the temperature difference between the battery cells in the module was 2.44℃. The simulation results are as follows. Figure 4 As shown, this demonstrates that the immersion module of this structure has a very good cooling effect.

[0063] Example 3:

[0064] This embodiment includes: a cylindrical battery cell 1, a module housing 2, a coolant inlet 3, a first coolant outlet 4, a second coolant outlet 5, a rectifier 6, a flow guide cone 7, and a separator 8.

[0065] In this embodiment, cylindrical battery cells are arranged closely around the center of the module housing on the module's circumference, with adjacent cells being tangent to each other and the center of the circle formed by the cells coinciding with the center of the module.

[0066] The individual cells are connected in series along the module's height. The coolant inlet is located at the center of the top of the module, for injecting coolant at a controlled flow rate. The coolant outlet is also located at the center of the top of the module, for discharging coolant. A guide cone is located at the center of the bottom of the module, for changing the direction of coolant flow. A rectifier is located on the inner wall of the module housing, for promoting coolant mixing. A baffle is installed between the top of the individual cells and the top of the module, for separating the coolant inlet and outlet channels.

[0067] Furthermore, the module contains 15 4680 cylindrical battery cells connected in series. The diameter and height of each cell are 46cm and 80cm, respectively, and the module diameter is 130cm.

[0068] Furthermore, the distances between the individual battery cells and the top and bottom of the module are 10cm and 20cm, respectively.

[0069] Furthermore, the distance between the two coolant outlets of the module and the center of the module is 39.1 cm.

[0070] Furthermore, the coolant inlet diameter is 20cm.

[0071] Furthermore, the coolant outlet diameter is 10cm.

[0072] Furthermore, the angle between the coolant outlet 1 and coolant outlet 2 of the module and the center of the module is 180°.

[0073] Furthermore, the rectifiers of the module are regular triangular prisms with a side length of 4.6cm and a thickness of 10cm. They are evenly distributed in the circumferential and axial directions of the module, with 5 rectifiers arranged in the circumferential direction and 6 rectifiers arranged in the axial direction.

[0074] Furthermore, the module's guide cone is conical with a apex angle of 120° and a bottom diameter of 46cm.

[0075] Furthermore, the coolant used in the module is a fluorinated liquid.

[0076] Furthermore, the flow rate at each coolant inlet is 2.8 L / min.

[0077] The COMSL simulation software was used to simulate this embodiment. When each battery cell was charged at 2C, the temperature difference between the battery cells in the module was 1.85℃. The simulation results are as follows. Figure 5 As shown, this demonstrates that the immersion module of this structure has a very good cooling effect.

[0078] The above description is merely illustrative of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the content of this specification or exceed the scope defined by the claims, all of which should fall within the protection scope of this invention.

Claims

1. An immersion liquid-cooled lithium battery module, characterized by, It includes a cylindrical battery cell (1), a module housing (2), a coolant inlet (3), a first coolant outlet (4), and a second coolant outlet (5); In the radial direction of the module, cylindrical battery cells (1) are closely arranged around the center of the module housing (2), and adjacent battery cells are tangent to each other; In the axial direction of the module, the battery cells (1) are connected in series; The coolant inlet (3) is located at the center of the top of the module and is used to inject coolant at a certain flow rate; The first coolant outlet (4) and the second coolant outlet (5) are located at the top of the module and are used to discharge the coolant; It also includes a rectifier (6), which is located on the inner wall of the module housing and is used to promote the mixing of coolant; It also includes a flow guide cone (7), which is located at the center of the bottom of the module and is used to change the flow direction of the coolant.

2. The immersion liquid-cooled lithium battery module according to claim 1, characterized in that, The rectifier (6) is triangular prism and is evenly distributed in the circumferential and axial directions of the module. There are 2 to 10 rectifiers (6) arranged in the circumferential direction and 3 to 10 rectifiers (6) arranged in the axial direction.

3. The immersion liquid-cooled lithium battery module according to claim 1, characterized in that, The guide cone (7) is conical in shape, with a apex angle of 10°~150° and a base diameter of 0.1 mm. r ~3 r , r The diameter of the battery cell.

4. The immersion liquid-cooled lithium battery module according to claim 3, characterized in that, The apex angle of the guide cone (7) is 45°~120°, and the bottom diameter is 0.

5. r ~2 r .

5. The immersion liquid-cooled lithium battery module according to claim 1, characterized in that, It also includes a separator (8), which is installed between the top of the battery cell (1) and the top of the module to separate the coolant inlet and outlet channels.

6. The immersion liquid-cooled lithium battery module according to claim 5, characterized in that, The center of the circle formed by the battery cells (1) coincides with the center of the module.

7. The immersion liquid-cooled lithium battery module according to claim 1, characterized in that, The distance between the individual battery cells and the top and bottom of the module is 0.

1. r ~ r The coolant inlet diameter is 0.1 mm. r ~2 r , r The diameter of the battery cell is given, and the flow rate at each coolant inlet is 1~10 L / min.

8. The immersion liquid-cooled lithium battery module according to claim 7, characterized in that, The distance between the individual battery cells and the top and bottom of the module is 0.

2. r ~0.8 r The coolant inlet diameter is 0.2 mm. r ~1.5 r The flow rate at each coolant inlet is 2~5 L / min.

9. The immersion liquid-cooled lithium battery module according to claim 7, characterized in that, The distance from the coolant outlet to the center of the module is 0.

1. R ~0.9 R The coolant outlet diameter is 0.05 mm. R ~0.5 R , R R is the radius of the module's cross-section.

10. The immersion liquid-cooled lithium battery module according to claim 8, characterized in that, The distance from the coolant outlet to the center of the module is 0.

5. R ~0.8 R The coolant outlet diameter is 0.05 mm. R ~0.3 R , R R is the radius of the module's cross-section.

11. The immersion liquid-cooled lithium battery module according to any one of claims 7 to 10, characterized in that, The coolant used is a fluorinated liquid.

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