Battery liquid cooling system

Abstract

Disclosed in the present application is a battery liquid cooling system, comprising: a battery module formed by stacking a plurality of battery cells; a battery casing, an accommodation recess being provided in the battery casing, and the battery module being assembled in the accommodation recess; flow channel plates, located between at least two adjacent battery cells, liquid cooling flow channels being provided in each flow channel plate, and the liquid cooling flow channels being spaced apart from the battery cells, or each flow channel plate being attached to a side surface of a battery cell on at least one side to form liquid cooling flow channels; an immersion liquid inlet, a cooling liquid being introduced into the accommodation recess through the immersion liquid inlet; and an immersion liquid outlet, the immersion liquid outlet being in communication with the accommodation recess, and the liquid cooling flow channels being in communication with the accommodation recess.

Description

Battery liquid cooling system

[0001] The present application claims priority to the Chinese patent application No. 2024222125022 filed on September 9, 2024 with the China Patent Office, the whole content of the above application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery liquid cooling system. BACKGROUND

[0003] With the rapid development of electric vehicles, energy storage systems and portable electronic devices, high-performance and high-energy-density lithium batteries as their core power source, the efficiency and reliability of their thermal management systems have become one of the key technical challenges. Although the traditional air cooling and direct contact liquid cooling systems can solve the heat dissipation of the battery pack to some extent, when facing high-power-density and large-capacity battery packs, their heat dissipation efficiency and temperature uniformity often cannot meet the ideal state. Therefore, the immersion liquid cooling system has gradually become a research hotspot due to its excellent heat dissipation performance. TECHNICAL PROBLEM

[0004] Currently, the immersion liquid cooling system mostly adopts a static immersion method, that is, the cooling liquid (usually an insulating liquid with low viscosity and high thermal conductivity) is statically surrounded around the battery monomer, and absorbs the heat generated by the battery during charging and discharging through heat conduction. However, this non-flowing mode has significant limitations: as the battery continues to work, the cooling liquid gradually warms up due to absorbing heat, resulting in a decrease in cooling efficiency, which may further cause the risk of battery overheating, affecting the battery life and system safety.

[0005] To overcome the above-mentioned defects, researchers have begun to explore the immersion liquid cooling scheme of flowing cooling liquid, in order to enhance the heat exchange efficiency of the cooling liquid by improving its flowability, and to achieve more uniform and efficient battery cooling. However, in the related battery pack design, a thin plate-shaped material with elasticity is often used as a spacer between the battery cells. The original intention of this design is to provide necessary mechanical support and insulation protection, but when facing flowing cooling liquid, its structural characteristics become a limiting factor, which is not sufficient to support the smooth flow of the cooling liquid, resulting in an increase in the flow resistance of the cooling liquid between the battery cells, a decrease in the flow speed, and even the formation of dead zones or vortexes in some areas, which seriously affects the effective heat transfer of the battery cells. TECHNICAL SOLUTION

[0006] The application provides a battery liquid cooling system, a battery liquid cooling system, comprising: a battery module, the battery module is stacked by a plurality of battery cells; a battery shell, the battery shell has a containing groove inside, the battery module is assembled in the containing groove; a flow channel plate, the flow channel plate is located between at least two adjacent battery cells, the flow channel plate is provided with a liquid cooling flow channel, the liquid cooling flow channel is arranged apart from the battery cell, or the flow channel plate is attached to at least one side of the battery cell side to form a liquid cooling flow channel; an immersion liquid inlet, the immersion liquid inlet is connected to the battery shell, and the immersion liquid inlet introduces cooling liquid into the containing groove; an immersion liquid outlet, the immersion liquid outlet is connected to the battery shell, and the immersion liquid outlet is communicated with the containing groove; wherein the liquid cooling flow channel is communicated with the containing groove. Advantages

[0007] The application provides a battery liquid cooling system, which has the following advantages: by using the above scheme, the flow channel plate with a clear liquid cooling flow channel is arranged between the battery cells, which can guide the cooling liquid to flow orderly and efficiently between the battery cells. This design avoids the situation that the cooling efficiency decreases after the cooling liquid is heated in the traditional static immersion method, because the flowing cooling liquid can continuously take away heat and maintain a low temperature through system circulation. BRIEF DESCRIPTION OF DRAWINGS [0007.1][According to Rule 91, correct on 08.01.2025] Figure 1 is a cross-sectional schematic view of a battery liquid cooling system according to an embodiment of the application;

[0008] [According to Rule 91, correct on 08.01.2025] Figure 2 is a schematic view of a flow channel plate structure according to an embodiment of the application;

[0009] [According to Rule 91, correct on 08.01.2025] Figure 3 is a schematic view of one side structure of a flow channel plate solution inlet and outlet according to an embodiment of the application;

[0010] [According to Rule 91, correct on 08.01.2025] Figure 4 is a schematic view of a flow channel plate structure according to an embodiment of the application;

[0011] [According to Rule 91, correct on 08.01.2025] Figure 5 is a schematic view of one side structure of a flow channel plate solution inlet and outlet according to an embodiment of the application;

[0012] [According to Rule 91, correct on 08.01.2025] Figure 6 is a schematic view of a flow channel plate structure according to an embodiment of the application;

[0013] [According to Rule 91, correct on 08.01.2025] Figure 7 is a schematic view of one side structure of a flow channel plate solution inlet and outlet according to an embodiment of the application.

[0014] Wherein, the reference signs have the following meanings: 1, flow channel plate; 11, liquid cooling channel; 12, liquid cooling flow channel; 13, convex rib; 14, solution inlet and outlet; 2, first surface; 3, second surface; 4, battery shell; 41, containing groove; 5, battery module; 51, battery cell; 6, immersion liquid inlet; 7, immersion liquid outlet.

[0015] Embodiments of the present application

[0016] The technical scheme adopted by the present application is:

[0017] A battery liquid cooling system, comprising: a battery module, the battery module is stacked by a plurality of battery cells; a battery shell, the battery shell has a containing groove inside, the battery module is assembled in the containing groove; a flow channel plate, the flow channel plate is located between at least two adjacent battery cells, the flow channel plate is provided with a liquid cooling flow channel, the liquid cooling flow channel is arranged apart from the battery cell, or the flow channel plate is attached to the side surface of at least one side of the battery cell to form a liquid cooling flow channel; an immersion liquid inlet, the immersion liquid inlet is connected to the battery shell, the immersion liquid inlet introduces cooling liquid into the containing groove; an immersion liquid outlet, the immersion liquid outlet is connected to the battery shell, the immersion liquid outlet is communicated with the containing groove; wherein the liquid cooling flow channel is communicated with the containing groove.

[0018] By adopting the above scheme, by arranging the flow channel plate with clear liquid cooling flow channel between the battery cells, the cooling liquid can be guided to flow orderly and efficiently between the battery cells. This design avoids the situation that the cooling efficiency of the cooling liquid decreases after being heated in the traditional static immersion method, because the flowing cooling liquid can continuously take away heat and maintain a low temperature through system circulation.

[0019] Optionally, a plurality of liquid cooling flow channels are provided, and the liquid cooling flow channels are arranged in parallel at equal intervals.

[0020] By adopting the above scheme, the equal-interval and parallel liquid cooling flow channels ensure the uniform distribution and flow of the cooling liquid in the battery pack, which means that each region of the battery cell can obtain similar cooling effect, avoiding the situation of local overheating or uneven cooling, thereby improving the overall performance and life of the battery pack.

[0021] Optionally, the liquid cooling flow channel is provided with a solution inlet and outlet at both ends, and the area of the solution inlet and outlet is the same as the cross-sectional area of the liquid cooling flow channel.

[0022] By adopting the above scheme, the area of the inlet and outlet is the same as the cross-sectional area of the liquid cooling flow channel, which means that when the cooling liquid enters and exits the flow channel, there will be no additional flow resistance caused by the sudden change of the cross-sectional area, and at the same time, it helps to ensure the uniform distribution of the cooling liquid among the multiple liquid cooling flow channels.

[0023] Optionally, the flow channel plate comprises a first surface and a second surface opposite to the first surface, a plurality of liquid cooling grooves are arranged on the first surface in sequence and are equidistant and parallel to each other, and a convex rib is formed between every two adjacent liquid cooling grooves in a direction perpendicular to the liquid cooling grooves.

[0024] By adopting the above scheme, the existence of the convex rib increases the overall structural strength of the flow channel plate. In the battery pack, the flow channel plate needs to withstand the pressure from the battery cell, the weight of the cooling liquid, and possible vibration and impact. The convex rib acts as a reinforcing rib, effectively dispersing and resisting these forces, improving the stability and durability of the flow channel plate. Although the convex rib itself does not directly participate in the flow of the cooling liquid, it can act as a bridge for heat conduction. When the heat generated by the battery cell is transmitted to the flow channel plate through the liquid cooling groove, the convex rib can quickly disperse the heat to other parts of the flow channel plate, and then through other liquid cooling grooves or heat dissipation structures to take away the heat.

[0025] Optionally, the second surface is also provided with a plurality of liquid cooling grooves and convex ribs corresponding to the first surface.

[0026] By adopting the above scheme, since the first surface and the second surface are both provided with liquid cooling grooves and convex ribs, the cooling liquid can flow on both surfaces at the same time, achieving double cooling efficiency. This design enables the battery pack to better control the temperature under high power output or extreme working conditions, improving the thermal management capability and safety of the system.

[0027] Optionally, the flow channel plate comprises a first surface and a second surface opposite to the first surface, and the liquid cooling flow channel is located between the first surface and the second surface.

[0028] By adopting the above scheme, the design of the internal liquid cooling flow channel helps to achieve thermal uniformity between the battery cells and within the battery cells. When the cooling liquid flows in the flow channel, it can uniformly take away the heat from various parts of the battery cell, preventing local overheating. This helps to improve the overall performance of the battery pack and prolong the service life.

[0029] Optionally, the length of the liquid cooling flow channel located at the edge of the flow channel plate from the edge of the flow channel plate is X1, the interval distance between every two adjacent liquid cooling flow channels is X2, and X1>X2.

[0030] By adopting the above scheme, it helps to reduce the edge effect caused by possible machining errors, uneven installation or external environmental influences at the edge of the flow channel plate. This edge effect may interfere with the flow of the cooling liquid and affect the heat conduction efficiency. Leaving a certain space at the edge of the flow channel plate can enhance the stability of the entire structure, that is, by offsetting the liquid cooling flow channel inward by a certain distance, it can ensure that the flow of the cooling liquid in the main working area is more stable and efficient.

[0031] Optionally, X2 is in the range of 5mm-6mm, and X1 is in the range of 7-8mm.

[0032] By adopting the above scheme, during the manufacturing and installation process, considering the particularity and precision requirement of the edge of the flow channel plate, the liquid cooling flow channel is arranged at a certain distance from the edge, which can reduce the manufacturing difficulty and installation risk.

[0033] Optionally, the thickness of the flow channel plate is not less than 4mm, and the distance between the liquid cooling flow channel and the first surface or the second surface is not less than 0.5mm.

[0034] By adopting the above scheme, the flow channel plate can provide a relatively solid support structure to prevent deformation or rupture during use, and the distance between the liquid cooling flow channel and the first surface and the second surface helps to achieve effective heat exchange between the cooling liquid and the battery cell.

[0035] Optionally, the thickness of the flow channel plate is not less than 4mm, and the depth of the liquid cooling channel is 1.5mm-3mm.

[0036] By adopting the above scheme, the depth of the liquid cooling channel can ensure stable flow of the cooling liquid in the channel, and also ensure sufficient heat exchange area. Shallow channel may not provide enough flow space, resulting in too fast flow rate of the cooling liquid, large pressure loss, and thus affecting the heat exchange efficiency; while too deep channel will increase the manufacturing cost and difficulty, and may not be conducive to the uniform distribution of the cooling liquid in the channel. Therefore, selecting appropriate channel depth is one of the key factors to ensure the performance of the cooling system.

[0037] [Corrected according to Rule 91 on 08.01.2025] Embodiment 1 of the present application, as shown in FIGS. 1-7, discloses a battery liquid cooling system, comprising a battery module 5, a battery shell 4, a flow channel plate 1, an immersion liquid inlet 6 and an immersion liquid outlet 7, the battery module 5 is stacked by a plurality of battery cells 51, the battery shell 4 has a containing groove 41 inside, the battery module 5 is assembled in the containing groove 41, specifically, the battery module 5 and the containing groove 41 can be fixed by structural glue, the flow channel plate 1 is located between at least two adjacent battery cells 51, the flow channel plate 1 is provided with a liquid cooling flow channel 12, the liquid cooling flow channel 12 is arranged between the battery cells 51, or the flow channel plate 1 is attached to at least one side of the battery cell side to form a liquid cooling flow channel 12; it should be noted that both ends of the liquid cooling flow channel 12 need to be communicated with the containing groove 41, the immersion liquid outlet 7 and the immersion liquid inlet 6 are connected to the battery shell 4, the immersion liquid outlet 7 is communicated with the containing groove 41; the immersion liquid inlet 6 introduces cooling liquid into the containing groove 41, and the cooling liquid flows through the liquid cooling flow channel 12 and finally flows out of the immersion liquid outlet 7, which can guide the cooling liquid to flow orderly and efficiently between the battery cells. This design avoids the situation that the cooling efficiency decreases after the cooling liquid is heated in the traditional static immersion method, because the flowing cooling liquid can continuously take away heat and maintain a lower temperature through system circulation. The immersion liquid inlet 6 can also be connected to a heat exchange device and a circulating pump to heat the cooling liquid flowing out of the containing groove 41, and this device is related to the prior art, so it is not described here.

[0038] It should be noted that the flow channel design between the battery cells in the battery module 5 in the immersion battery pack of embodiment 1 is not limited to flowing immersion liquid or non-flowing immersion liquid.

[0039] [According to the rules 91 correction 08.01.2025] In a specific embodiment, referring to FIGS. 2-3, the flow channel plate 1 is made of a porous diaphragm material about 4 mm thick, which can be more than 4 mm. The porous design allows the cooling liquid to enter the material inside, improving the heat conduction performance. Of course, in other embodiments, other materials can also be used, and the present embodiment is not limited. The flow channel plate 1 includes a first surface 2 and a second surface 3 opposite to the first surface 2. The first surface 2 or the second surface 3 is provided with a plurality of liquid cooling channels 11, and the liquid cooling channels 12 are arranged in parallel at equal intervals. The spacing of the liquid cooling channels 11 can be selected to be 5-6 mm, and the depth of the liquid cooling channel 11 is 3 mm, that is, the thickness of the flow channel plate 1 at the liquid cooling channel is 1 mm. The liquid cooling channel 11 is attached to the side wall of the battery cell, so that the liquid cooling channel 11 is enclosed to form a liquid cooling channel 12. The liquid cooling channel 12 is provided with a solution inlet and outlet 14 at both ends, and the area of the solution inlet and outlet 14 is the same as the cross-sectional area of the liquid cooling channel 12, so that the cooling liquid flows uniformly in the liquid cooling channel 12 in the battery pack. Between every two liquid cooling channels 11, a convex rib 13 is formed, which is used to abut the battery cell to resist the impact force when the battery pack is impacted.

[0040] It should be noted that the cross section of the liquid cooling channel 11 includes but is not limited to U-shaped, rectangular or semicircular, and the spacing and depth of the liquid cooling channel 11 can be changed based on actual conditions, and the present embodiment is not limited. In some embodiments, the convex rib 13 can be integrally formed with the flow channel plate 1, or it can be wrapped with flexible material on the flat plate to form the convex rib 13. After multiple winding, a plurality of convex ribs 13 are formed, and the liquid cooling channel 11 is formed between adjacent convex ribs 13.

[0041] When the liquid cooling system of the battery pack is working, the cooling liquid can flow in the liquid cooling channel 12 in the battery pack under the action of an additional liquid cooling pump, thereby achieving the heat exchange effect of the battery cell, and also having a certain shock absorption and buffering effect.

[0042] [According to the rules 91 correction 08.01.2025] in a specific embodiment, refer to Figs. 4-5, the flow channel plate 1 includes a first surface 2 and a second surface 3 opposite to the first surface 2, the first surface 2 and the second surface 3 are provided with a plurality of liquid cooling channels 11, every two adjacent liquid cooling channels 11 on the same surface form a convex rib 13, and the liquid cooling channels 11 on the same plane are arranged in turn, equidistantly and parallel, so that the first surface 2 and the second surface 3 of the flow channel plate 1 both have liquid cooling channels 11 and convex ribs 13, preferably, the convex ribs 13 and the liquid cooling channels 11 of the two surfaces are opposite to each other; the spacing of the liquid cooling channels 11 can be selected as 5-6mm, the depth of the liquid cooling channels 11 on the first plane and the liquid cooling channels 11 on the second plane is 1.5mm, that is, the spacing distance between the liquid cooling channels 11 on the first plane and the liquid cooling channels 11 on the second plane is 1mm, the liquid cooling channels 11 of the first surface 2 and the second surface 3 of the flow channel plate 1 are respectively attached to the opposite side walls between the two battery cells, so that the liquid cooling channels 11 form a liquid cooling channel 12, the two ends of the liquid cooling channel 12 are provided with solution inlets and outlets 14, the area of the solution inlet and outlet 14 is the same as the cross-sectional area in the liquid cooling channel 12, so that the cooling liquid flows uniformly in the liquid cooling channel 12 in the battery pack.

[0043] It should be noted that the cross section of the liquid cooling channel 11 includes but is not limited to U-shaped, rectangular or semicircular, and the spacing and depth of the liquid cooling channel 11 can be changed based on the actual situation, which is not limited in the embodiment; in some embodiments, the convex rib 13 can be integrally formed with the flow channel plate 1, or can be wrapped with flexible material on the plane plate to form the convex rib 13, and a plurality of convex ribs 13 are formed after multiple winding, and the liquid cooling channel 11 is formed between adjacent convex ribs 13.

[0044] [According to the rules 91 correction 08.01.2025] in a specific embodiment, refer to Figs. 6-7, the flow channel plate 1 includes a first surface 2 and a second surface 3 opposite to the first surface 2, and the liquid cooling channel 12 is located between the first surface 2 and the second surface 3. The liquid cooling channels 12 are arranged in turn, equidistantly and parallel, the spacing of the liquid cooling channels 12 can be selected as 5-6mm, and the distance between the liquid cooling channel 12 and the first surface 2 or the second surface 3 is not less than 0.5mm, which can be selected as 0.5mm. Therefore, the first surface 2 and the second surface 3 of the flow channel plate 1 are both planes, directly attached to the battery cell, and when the liquid cooling system of the battery pack works, the cooling liquid can flow in the liquid cooling channel 12 in the battery pack under the action of an additional liquid cooling pump, so as to realize the heat exchange effect of the battery cell, and the heat exchange is carried out by the whole flow channel plate 1, and the temperature uniformity is more optimal.

[0045] It should be noted that the cross section of the liquid cooling channel 11 includes but is not limited to U-shaped, rectangular or semicircular, and the spacing and depth of the liquid cooling channel 11 can be changed based on actual conditions, and the embodiment is not limited specifically.

[0046] [Corrected according to Rule 91 on 08.01.2025] In the above embodiment, referring to FIGS. 3, 5 and 7, the liquid cooling channel 12 located at the edge of the flow channel plate 1 is set to have a length X1 from the edge of the flow channel plate 1, and the interval distance between every two adjacent liquid cooling channels 12 is X2, then X1>X2. Wherein, the range of X2 is 5-6mm, and the range of X1 is 7-8mm, such design helps to reduce the edge effect caused by the possible machining error, uneven installation or external environmental influence of the edge of the flow channel plate 1. During manufacturing and installation, considering the particularity and precision requirement of the edge of the flow channel plate 1, setting the liquid cooling channel 12 at a certain distance from the edge can reduce the manufacturing difficulty and installation risk.

[0047] In summary, the battery liquid cooling system provided by the present application has the following technical effects:

[0048] 1. Improve heat dissipation efficiency: By setting clear liquid cooling channels 12 between the cells, the cooling liquid flows in an orderly manner, which can significantly improve the heat exchange efficiency. The flowing cooling liquid can continuously carry away the heat generated by the cells and maintain a low temperature through system circulation, thereby effectively preventing the battery from overheating and improving the overall heat dissipation capacity of the battery pack.

[0049] 2. Improve temperature uniformity: The flowing cooling liquid can be more evenly distributed between the cells, reducing thermal stress caused by temperature gradients and improving the temperature uniformity inside the battery pack. This helps to prolong the battery life and improve the stability and reliability of the battery system.

[0050] 3. Reduce flow resistance: Compared with traditional designs that use elastic sheets as spacers, the flow channel plate 1 in the present application has clear liquid cooling channels 12, which can significantly reduce the flow resistance of the cooling liquid between the cells. This helps to increase the flow rate of the cooling liquid, improve heat exchange efficiency, and reduce the risk of forming dead zones or vortexes between the cells.

[0051] 4. Enhance structural strength: The flow channel plate 1 not only serves as a flow channel for the cooling liquid, but also has certain structural strength, which can provide necessary mechanical support for the battery pack. This design helps to enhance the overall structural stability of the battery pack and reduce the risk of damage caused by vibration or impact.

[0052] 5. Improve system safety: By improving heat dissipation efficiency and temperature uniformity, the liquid cooling channel 12 structure of the immersed battery helps to reduce the safety risks such as battery overheating and fire.

Claims

1. A battery liquid cooling system, comprising: a battery module (5) stacked by a plurality of battery cells (51) ; a battery housing (4) having a receiving groove (41) therein, the battery module (5) being fitted in the receiving groove (41) ; a flow channel plate (1) located between at least two adjacent battery cells (51), the flow channel plate (1) being provided with liquid cooling flow channels (12), the liquid cooling flow channels (12) being spaced apart from the battery cells (51), or the flow channel plate (1) being attached to at least one side of the battery cell side surface to form liquid cooling flow channels (12) ; a liquid immersion inlet (6) connected to the battery housing (4), the liquid immersion inlet (6) introducing cooling liquid into the receiving groove (41) ; a liquid immersion outlet (7) connected to the battery housing (4), the liquid immersion outlet (7) being in communication with the receiving groove (41) ; wherein the liquid cooling flow channels (12) are in communication with the receiving groove (41).

2. The battery liquid cooling system of claim 1, wherein, A plurality of liquid cooling flow channels (12) are provided and arranged in parallel at equal intervals.

3. The battery liquid cooling system of claim 2, wherein, Both ends of the liquid cooling flow channel (12) are provided with solution inlets and outlets (14), and the area of the solution inlets and outlets (14) is the same as the cross-sectional area of the liquid cooling flow channel (12).

4. The battery liquid cooling system of claim 2, wherein, The flow channel plate (1) comprises a first surface (2) and a second surface (3) opposite to the first surface (2), a plurality of liquid cooling grooves (11) and protrusions (13) are arranged on the first surface (2) at equal intervals and in parallel, and in the direction perpendicular to the liquid cooling grooves (11), a protrusion (13) is formed between every two adjacent liquid cooling grooves (11).

5. The battery liquid cooling system of claim 4, wherein, The second surface (3) is also provided with a plurality of liquid cooling grooves (11) and protrusions (13) corresponding to the first surface (2).

6. The battery liquid cooling system of claim 2, wherein, The flow channel plate (1) comprises a first surface (2) and a second surface (3) opposite to the first surface (2), and the liquid cooling flow channels (12) are located between the first surface (2) and the second surface (3).

7. A battery liquid cooling system according to any one of claims 1-6, wherein, The length of the liquid cooling flow channel (12) located at the edge of the flow channel plate (1) from the edge of the flow channel plate (1) is X1, and the interval distance between every two adjacent liquid cooling flow channels (12) is X2, then X1>X2.

8. The battery liquid cooling system of claim 7, wherein, The range of X2 is 5mm-6mm, and the range of X1 is 7-8mm.

9. The battery liquid cooling system of claim 6, wherein, The thickness of the flow channel plate (1) is not less than 4mm, and the distance between the liquid cooling flow channel (12) and the first surface (2) or the second surface (3) is not less than 0.5mm.

10. The battery liquid cooling system of claim 4 or 5, wherein, The thickness of the flow channel plate (1) is not less than 4mm, and the depth of the liquid cooling groove (11) is 1.5mm-3mm.

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