Battery pack

Abstract

The invention provides a battery pack. The battery pack comprises a box body and a liquid cooling pipe, and a battery module and immersion liquid for immersing the battery module are arranged in the box body; the liquid cooling pipe comprises a liquid cooling main body arranged in the box body and a liquid inlet pipe nozzle and a liquid outlet pipe nozzle which are communicated with the liquid cooling main body, the liquid cooling main body is in contact with the immersion liquid, and the liquid inlet pipe nozzle and the liquid outlet pipe nozzle are communicated with the outside of the box body. The immersion liquid is arranged in the box body and does not circularly flow with the outside, so that the mechanical strength and structural air tightness requirements of the box body are reduced, the processing difficulty is reduced, the liquid cooling pipe is arranged in the box body, and a plurality of convex parts are arranged on the outer wall of the liquid cooling main body, so that the contact area between the liquid cooling main body and the immersion liquid can be increased; the liquid inlet pipe nozzle and the liquid outlet pipe nozzle of the liquid cooling pipe are communicated with the outside of the box body, and cooling liquid circularly flowing with the outside can be arranged in the liquid cooling pipe, so that the heat exchange efficiency of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack. Background Art

[0002] In the related art, immersed battery packs can be divided into immersed battery packs with circulating immersion liquid and immersed battery packs with stationary immersion liquid.

[0003] For immersed battery packs with circulating immersion fluid, the fluid can continuously flow into the battery pack at a constant temperature, achieving a significant cooling effect. However, the circulating immersion fluid places high demands on the battery pack's mechanical strength and structural airtightness, making processing more challenging. For immersed battery packs with stationary immersion fluid, the mechanical strength and structural airtightness requirements are lower, making processing even easier. However, a stationary immersion battery pack cannot exchange heat with the outside world and cannot meet the heat dissipation requirements of the battery pack during high-power charging and discharging. Summary of the Invention

[0004] The embodiments of the present application provide a battery pack that can improve the technical problem that an immersed battery pack with stationary immersion liquid cannot exchange heat with the outside world and cannot meet the heat dissipation requirements of the battery pack during charging and discharging at high power.

[0005] An embodiment of the present application provides a battery pack, comprising:

[0006] A box body, wherein a battery module and an immersion liquid for immersing the battery module are arranged in the box body;

[0007] The liquid cooling tube includes a liquid cooling body arranged in the box body and a liquid inlet nozzle and a liquid outlet nozzle connected to the liquid cooling body, the liquid cooling body is in contact with the immersion liquid, the liquid inlet nozzle and the liquid outlet nozzle are connected to the outside of the box body, and the outer wall of the liquid cooling body is provided with multiple protrusions.

[0008] In some embodiments, a cross-sectional area of ​​the protrusion farther from the central axis of the liquid-cooled body is smaller than a cross-sectional area of ​​the protrusion closer to the central axis of the liquid-cooled body.

[0009] In some embodiments, the shape of the protrusion includes a cone, a pyramid, a truncated cone, or a truncated pyramid.

[0010] In some embodiments, the liquid cooling tube includes at least one of a first sub-tube or a second sub-tube, the liquid cooling body of the first sub-tube is arranged between the side wall of the battery module and the side wall of the box body, and the liquid cooling body of the second sub-tube is arranged between the top surface of the battery module and the top wall of the box body.

[0011] In some embodiments, the liquid inlet nozzle and the liquid outlet nozzle of each of the liquid cooling tubes are both disposed on the side wall of the same side of the box.

[0012] In some embodiments, the liquid cooling tube includes at least the second sub-tube, the immersion liquid includes a phase change material, and at least a portion of the second sub-tube is located between the liquid surface of the immersion liquid and the top wall of the box.

[0013] In some embodiments, the battery pack includes a plurality of heat exchange protrusions arranged along the length direction of the box body or the width direction of the box body, and two adjacent heat exchange protrusions are spaced apart. The heat exchange protrusions include a first protrusion arranged between the top wall of the box body and the battery module and / or a second protrusion arranged between the bottom wall of the box body and the battery module, and the battery module is arranged in contact with the heat exchange protrusions.

[0014] In some embodiments, the battery pack includes a first protrusion and a second protrusion, and a thickness of the first protrusion is less than or equal to a thickness of the second protrusion.

[0015] In some embodiments, the thickness of the second protrusion is 1.5 to 10 times the thickness of the first protrusion.

[0016] In some embodiments, the battery pack also includes a liquid cooling plate, which is arranged between the inner wall of the box and the heat exchange protrusion. The liquid cooling plate includes a main body and a liquid cooling interface connected to the main body, and the liquid cooling interface is connected to the outside of the box.

[0017] In some embodiments, the battery pack also includes a liquid cooling plate, which is integrally arranged with the top wall of the box or the bottom wall of the box. The liquid cooling plate includes a main body and a liquid cooling interface connected to the main body, and the liquid cooling interface is connected to the outside of the box.

[0018] In some embodiments, the liquid cooling plate and the heat exchange protrusion are integrally provided.

[0019] In some embodiments, the battery module includes multiple battery cells, and a structural member is arranged between two adjacent battery cells. The battery cell includes adjacent first and second side walls, the area of ​​the first side wall is larger than the area of ​​the second side wall, and the structural member is in contact with the first side wall.

[0020] Beneficial effects of the embodiments of the present application:

[0021] In the embodiments of the present application, an immersion liquid is provided in the box body, and the immersion liquid does not circulate with the outside world, thereby reducing the mechanical strength and structural airtightness requirements of the box body and reducing the processing difficulty. A liquid cooling tube is provided in the box body, and a plurality of protrusions are provided on the outer wall of the liquid cooling body, which can increase the contact area between the liquid cooling body and the immersion liquid. The liquid inlet nozzle and the liquid outlet nozzle of the liquid cooling tube are connected to the outside of the box body, and a coolant that circulates with the outside world can be provided inside the liquid cooling tube, thereby improving the heat exchange efficiency of the battery pack and improving the technical problem that the immersed battery pack with stationary immersion liquid cannot exchange heat with the outside world and cannot meet the heat dissipation requirements of the battery pack under high power charging and discharging. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a three-dimensional schematic diagram of a battery pack provided in an embodiment of the present application;

[0024] Figure 2 yes Figure 1 Schematic diagram of the disassembled structure of the battery pack;

[0025] Figure 3 yes Figure 2 Another partial structural diagram in FIG;

[0026] Figure 4 This is a force simulation diagram of the cover of an immersed battery pack with circulating immersion liquid in the related art;

[0027] Figure 5 is a partially enlarged structural schematic diagram of a liquid cooling body provided in an embodiment of the present application;

[0028] Figure 6 This is an assembly diagram of the liquid cooling plate and the heating protrusion provided in an embodiment of the present application;

[0029] Figure 7 yes Figure 6 Schematic diagram of the enlarged structure at A in the middle;

[0030] Figure 8 yes Figure 2 Schematic diagram of the partial disassembly structure of the battery module;

[0031] Figure 9 It is a structural schematic diagram of the bottom wall of the box body of an embodiment of the present application.

[0032] Description of reference numerals:

[0033] The box body 10, the top wall 10a of the box body 10, the side walls 10b of the box body 10, the bottom wall 10c of the box body 10, and the ribs 11;

[0034] Battery module 20, battery cell 21, first side wall 211, second side wall 212, structural member 22, end plate 23, bus bar 24;

[0035] Liquid cooling tube 30, liquid cooling body 31, protrusion 311, liquid inlet nozzle 321, liquid outlet nozzle 322, first sub-tube 301, second sub-tube 302;

[0036] Heat exchange protrusion 40, first protrusion 41, second protrusion 42;

[0037] Liquid cooling plate 50, main body 51, liquid cooling interface 52;

[0038] The thickness s1 of the first protrusion 41 and the thickness s2 of the second protrusion 42;

[0039] The height direction D1 of the box body 10 , the length direction D2 of the box body 10 , and the width direction D3 of the box body 10 . DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; and "inside" and "outside" refer to the outline of the device.

[0041] The embodiment of the present application provides a battery pack, such as Figures 1 to 3 As shown, the battery pack includes a box body 10 and a liquid cooling tube 30. The box body 10 is provided with a battery module 20 and an immersion liquid (not shown in the figure) for immersing the battery module 20; the liquid cooling tube 30 includes a liquid cooling body 31 arranged in the box body 10 and a liquid inlet nozzle 321 and a liquid outlet nozzle 322 connected to the liquid cooling body 31. The liquid cooling body 31 is in contact with the immersion liquid, and the liquid inlet nozzle 321 and the liquid outlet nozzle 322 are connected to the outside of the box body 10.

[0042] like Figure 2As shown, the box body 10 includes a top wall 10a and a bottom wall 10c opposite to each other, and a side wall 10b disposed between the top wall 10a and the bottom wall 10c. The side wall 10b is connected to the edge of the top wall 10a and the edge of the bottom wall 10c to form a sealed accommodation space. The number of side walls 10b can be set as needed. Figure 1 The number of side walls 10b is four for illustration, which should not be construed as limiting the present application.

[0043] like Figure 1 and Figure 2 As shown, the battery module 20 is disposed in the accommodation space of the box body 10. The battery module 20 includes a plurality of stacked battery cells 21.

[0044] The immersion liquid immerses the battery module 20, wherein immersion means that the immersion liquid contacts the battery module 20. It should be noted that when the immersion liquid is a single-phase immersion liquid, the immersion liquid can almost fill the accommodation space in the box 10. When the immersion liquid is a phase change material, the liquid level of the immersion liquid can be lower than the height of the box 10, that is, the liquid level of the immersion liquid can be spaced apart from the top wall 10a of the box 10. The height of the box 10 refers to the direction from the bottom wall 10c of the box 10 to the top wall 10a of the box 10, that is, Figure 1 and Figure 2 The direction shown by D1 in FIG.

[0045] The immersion fluid can include fluorinated liquids, hydrofluoroethers, silicone oils, and hydrocarbon compounds. The immersion fluid provides both cooling and insulation. The battery module 20 generates heat during operation, and the immersion fluid, in contact with the battery module 20, helps cool the module and prevents it from heating too quickly.

[0046] like Figure 2 As shown, the liquid cooling pipe 30 includes a liquid cooling body 31, a liquid inlet nozzle 321 and a liquid outlet nozzle 322. The liquid cooling body 31 is disposed in the accommodation space of the box body 10, and the liquid outlet nozzle 322 is disposed through the side wall 10b of the box body 10.

[0047] See also Figure 5 The liquid cooling tube 30 is a hollow tubular structure. The cross section of the inner wall of the liquid cooling tube 30 can be circular, square, oval, etc. The coolant can flow along the interior of the liquid cooling tube 30.

[0048] like Figure 2 As shown, the liquid cooling body 31 is disposed in the housing 10. The extension direction of the liquid cooling body 31 can be set as needed. For example, the shape of the liquid cooling body 31 can match the shape of the housing 10, thereby making the battery pack structure more compact.

[0049] like Figure 5As shown, the outer wall of the liquid-cooling body 31 is provided with multiple protrusions 311. By providing multiple protrusions 311, the surface area of ​​the liquid-cooling body 31 can be increased, thereby improving the heat exchange capacity of the liquid-cooling body 31. It should be noted that the protrusions 311 do not need to be provided on the outer walls of the liquid inlet nozzle 321 and the liquid outlet nozzle 322, so as to prevent the protrusions 311 from affecting the seal between the liquid inlet nozzle 321, the liquid outlet nozzle 322 and the housing 10. In other words, the protrusions 311 can be provided only on the liquid-cooling body 31.

[0050] In some embodiments, the inner diameter of the liquid cooling tube 30 ranges from 1 mm to 30 mm, and the outer diameter of the liquid cooling tube 30 ranges from 1 mm to 30 mm. The outer diameter of the liquid cooling tube 30 refers to the maximum dimension of the cross-section of the liquid cooling tube 30 excluding the protrusion 311, while the inner diameter of the liquid cooling tube 30 refers to the maximum dimension of the inner wall in the cross-section. The outer diameter of the liquid cooling tube 30 is greater than the inner diameter of the liquid cooling tube 30. Half the difference between the outer diameter and the inner diameter of the liquid cooling tube 30 is the wall thickness of the liquid cooling tube 30.

[0051] Optionally, the inner diameter of the liquid cooling tube 30 is 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc.

[0052] Optionally, the outer diameter of the liquid cooling tube 30 is 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc.

[0053] The number of liquid cooling tubes 30 can be set as needed. For example, there can be one or more liquid cooling tubes 30. The multiple liquid cooling tubes 30 can be arranged along the height direction D1 of the box body 10. The height direction D1 of the box body 10 is the direction from the bottom wall 10c of the box body 10 to the top wall 10a of the box body 10.

[0054] The liquid inlet nozzle 321, the liquid cooling body 31, and the liquid outlet nozzle 322 form a channel for the flow of coolant. Coolant can flow into the liquid cooling body 31 through the liquid inlet nozzle 321 and out through the liquid outlet nozzle 322. The liquid cooling tube 30 can exchange heat with the outside world through the coolant, conducting heat from the interior of the housing 10 out of the housing 10 via the coolant, thereby lowering the temperature within the housing 10 and improving the heat exchange efficiency of the battery pack, making the battery pack suitable for the heat dissipation requirements of high-power charging and discharging. The coolant can be a refrigerant such as R134a.

[0055] Alternatively, as Figure 1 and Figure 2 As shown, the liquid inlet nozzle 321 and the liquid outlet nozzle 322 are arranged on the same side of the box body 10, so that the liquid inlet nozzle 321 and the liquid outlet nozzle 322 are more convenient to operate when connected to the external pipeline. The external pipeline can be used to provide circulating coolant for the liquid cooling tube 30.

[0056] In some embodiments, the liquid inlet nozzle 321 and the liquid outlet nozzle 322 may also be disposed on different sides of the box body 10 .

[0057] like Figure 4 As shown, Figure 4 This is a force simulation diagram of the box cover of an immersion battery pack with circulating immersion liquid in the related art. Different pressure levels are distinguished by different colors in the simulation diagram. In the color bar chart on the left, the pressure value decreases from top to bottom. That is to say, the upper color represents a larger pressure value, and the lower color represents a smaller pressure value. Among them, the pressure in the red area is the largest, and the pressure in the blue area is relatively small. Among them, the pressure in the middle area of ​​the box cover is greater than the pressure in the edge area of ​​the box cover. That is to say, in the immersion battery pack with circulating immersion liquid, the force on the box cover is uneven. In order to prevent the box cover from being deformed or damaged under pressure, it is necessary to make the box cover able to withstand the pressure in the middle area (that is, the pressure value in the red area), which puts higher requirements on the mechanical strength of the box cover, resulting in increased processing difficulty and increased processing cost.

[0058] In this application, however, the immersion liquid does not need to circulate with the outside world. Compared to battery packs with circulating immersion liquid, the force applied to the housing 10 is more uniform, the mechanical strength requirements for the housing 10 are lower, and the processing difficulty of the housing 10 is relatively low. Therefore, the battery pack of this application can not only reduce the processing difficulty of the battery pack housing 10, but also meet the heat dissipation requirements of the battery pack under high-power charging and discharging.

[0059] When the cell 21 in the battery module 20 opens its valve, the substance ejected from the cell 21 will contaminate the immersion liquid. Since the immersion liquid in the box 10 is not exchanged with the outside world, it will not affect the immersion liquid of other parallel battery packs, reducing safety hazards.

[0060] In some embodiments, the cross-sectional area of ​​the protrusion 311 away from the central axis of the liquid-cooled body 31 is smaller than the cross-sectional area of ​​the protrusion 311 closer to the central axis of the liquid-cooled body 31. This means that the protrusion 311 has a variable cross-sectional area in the height direction. For ease of description, the end of the protrusion 311 away from the liquid-cooled body 31 is referred to as the top end, and the end of the protrusion 311 closer to the liquid-cooled body 31 is referred to as the bottom end. The height direction of the protrusion 311 is the direction from the bottom end of the protrusion 311 to the top end of the protrusion 311. The cross-sectional area refers to the area on a plane perpendicular to the height direction of the protrusion 311. The cross-sectional area at the top end of the protrusion 311 is smaller than the cross-sectional area at the bottom end of the protrusion 311.

[0061] The shape of the convex portion 311 can be set as needed. The convex portion 311 can be tapered, such as conical, pyramidal, etc. The convex portion 311 can be a table, such as a truncated table, a prism, etc., but is not limited thereto. Figure 53 shows a case where the convex portion 311 is a quadrangular pyramid. The convex portion 311 can be formed by knurling or toothing.

[0062] In some embodiments, the height of the protrusion 311 is greater than the wall thickness of the liquid-cooling body 31. The wall thickness of the liquid-cooling body 31 refers to half of the difference between the outer diameter of the liquid-cooling body 31 and the inner diameter of the liquid-cooling body 31.

[0063] In some embodiments, the liquid cooling tube 30 includes at least one of the first sub-tube 301 or the second sub-tube 302. The liquid cooling body 31 of the first sub-tube 301 is arranged between the side wall of the battery module 20 and the side wall 10b of the box body 10, and the liquid cooling body 31 of the second sub-tube 302 is arranged between the top surface of the battery module 20 and the top wall 10a of the box body 10.

[0064] The first sub-tube 301 and the second sub-tube 302 differ in position and shape. Figure 2 As shown, the first sub-tube 301 is disposed between the battery module 20 and the side wall 10b of the box body 10. The first sub-tube 301 can surround the outer periphery of the side wall of the battery module 20. The number of the first sub-tubes 301 can be set as needed. Figure 2 , there are two first sub-tubes 301. When there are multiple first sub-tubes 301, the multiple first sub-tubes 301 can be spaced apart in the height direction D1 of the housing 10 to exchange heat with immersion liquids at different depths.

[0065] like Figure 3 As shown, Figure 3 and Figure 2 The difference is that the box 10 is omitted and Figure 3 The battery module 20 and the liquid cooling tube 30 are in an assembled state. The second sub-tube 302 can be set between the top wall 10a of the box body 10 and the battery module 20. The number of the second sub-tubes 302 can be set as needed. Figure 3 3 shows a case where the number of second sub-tubes 302 is 2. When there are multiple second sub-tubes 302, the multiple second sub-tubes 302 can be arranged at intervals to exchange heat with immersion liquid in different areas.

[0066] Alternatively, multiple second sub-tubes 302 may be connected in series. This means that the liquid outlet of one second sub-tube 302 may be connected to the liquid inlet of another adjacent second sub-tube 302. This arrangement simplifies the assembly process of the liquid cooling tube 30 and the housing 10.

[0067] In some embodiments, as Figure 2 and Figure 3As shown, the liquid inlet nozzle 321 and the liquid outlet nozzle 322 of each liquid cooling tube 30 are arranged on the side wall of the same side of the box body 10, so that the liquid inlet nozzle 321 and the liquid outlet nozzle 322 are easier to operate when connected to the external pipeline. The external pipeline can be used to provide circulating coolant for the liquid cooling tube 30.

[0068] In some embodiments, the liquid cooling tube 30 includes at least a second sub-tube 302 , the immersion liquid includes a phase change material, and at least a portion of the second sub-tube 302 is located between the liquid surface of the immersion liquid and the top wall 10 a of the box 10 .

[0069] The immersion liquid includes a phase change material, such as a fluorinated liquid. Phase change materials have a low boiling point. When the ambient heat reaches certain conditions, they utilize latent heat to absorb heat and produce a boiling phase change, thereby cooling the battery module 20. After the immersion liquid evaporates, the immersion liquid vapor rises along the height direction D1 of the housing 10 and contacts the second sub-tube 302. Because coolant flows through the interior of the second sub-tube 302, the temperature of the second sub-tube 302 is lower than the temperature of the immersion liquid vapor. When the immersion liquid vapor contacts the second sub-tube 302, it condenses on the surface of the second sub-tube 302 and becomes liquid, then drips into the housing 10, achieving evaporation-condensation cycle heat exchange.

[0070] It should be noted that since the surface of the liquid-cooled body 31 is provided with multiple protrusions 311, the protrusions 311 have a variable cross-section in the height direction, which can greatly increase the effective heat transfer area between the immersion liquid and the liquid-cooled body 31, so that the phase-change immersion liquid produces a large number of bubble nucleate boiling cores, promotes the generation and escape of bubbles, and thus accelerates the evaporation and condensation speed of the immersion liquid and improves the heat exchange efficiency.

[0071] When the immersion fluid is single-phase, convection is the primary method of heat exchange between the immersion fluid and the battery module 20, requiring a larger amount of immersion fluid. When the immersion fluid is a phase-change material, convection is the primary method of heat exchange between the immersion fluid and the battery module 20, supplemented by latent heat of phase change. With the same heat exchange capacity, the amount of immersion fluid used can be reduced, thereby increasing the energy density per unit mass of the battery pack.

[0072] In some embodiments, as Figure 2 and Figure 3 As shown, the battery pack includes a plurality of heat exchange protrusions 40 arranged along the length direction D2 of the box body 10 or the width direction D3 of the box body 10, and two adjacent heat exchange protrusions 40 are spaced apart. The heat exchange protrusions 40 include a first protrusion 41 arranged between the top wall 10a of the box body 10 and the battery module 20 and / or a second protrusion 42 arranged between the bottom wall 10c of the box body 10 and the battery module 20. The battery module 20 is arranged in contact with the heat exchange protrusion 40.

[0073] The first protrusion 41 and the second protrusion 42 are located at different positions. The first protrusion 41 contacts the upper surface of the battery module 20, and the second protrusion 42 contacts the lower surface of the battery module 20. Figure 2 and Figure 3 As shown, a plurality of second protrusions 42 are shown. Figure 6 and Figure 7 As shown, a plurality of first protrusions 41 are shown.

[0074] Multiple heat exchange protrusions 40 can be arranged along the length direction D2 or the width direction D3 of the housing 10, with adjacent heat exchange protrusions 40 spaced apart to form a groove. The heat exchange protrusions 40 are arranged in contact with the battery module 20, thereby increasing the contact area between the battery module 20 and the immersion liquid and reducing the temperature difference between the battery module 20 and the immersion liquid.

[0075] Optionally, the shape of the heat exchange protrusions 40 can be configured as desired, and this application does not impose any restrictions thereto. For example, the heat exchange protrusions 40 can extend in a straight line, a broken line, or a curved line. When the heat exchange protrusions 40 extend in a straight line, they can be formed as straight fins. When the heat exchange protrusions 40 extend along a broken line, they can be formed as serrated fins. When the heat exchange protrusions 40 extend along a curved line, they can be formed as wavy fins. The heat exchange protrusions 40 can also have other shapes, as long as grooves are formed between two adjacent heat exchange protrusions 40. Figure 2 、 Figure 3 、 Figure 6 and Figure 7 Straight fins are shown, but this should not be construed as limiting the present application.

[0076] In some embodiments, the battery pack includes a first protrusion 41 and a second protrusion 42, and a thickness s1 of the first protrusion 41 is less than or equal to a thickness s2 of the second protrusion 42. The thickness s1 of the first protrusion 41 refers to the dimension of the first protrusion 41 in the direction in which the plurality of first protrusions 41 are arranged. The thickness s2 of the second protrusion 42 refers to the dimension of the second protrusion 42 in the direction in which the plurality of second protrusions 42 are arranged.

[0077] In some embodiments, the arrangement direction of the first protrusions 41 can be the same as the arrangement direction of the second protrusions 42. For example, the first protrusions 41 and the second protrusions 42 can both be arranged along the width direction D3 of the box body 10. Alternatively, the first protrusions 41 and the second protrusions 42 can both be arranged along the length direction D2 of the box body 10.

[0078] In some embodiments, the arrangement direction of the first protrusions 41 can be different from the arrangement direction of the second protrusions 42. For example, the second protrusions 42 are arranged along the width direction D3 of the housing 10, and the first protrusions 41 are arranged along the length direction D2 of the housing 10. Alternatively, the second protrusions 42 are arranged along the length direction D2 of the housing 10, and the first protrusions 41 are arranged along the width direction D3 of the housing 10. With this arrangement, the battery module 20 can be evenly heated from different directions.

[0079] like Figure 3 , showing the thickness s2 of the second protrusion 42. Figure 7 , shows the thickness s1 of the first protrusion 41. When the immersion liquid is a single-phase immersion liquid, the thickness s1 of the first protrusion 41 may be equal to the thickness s2 of the second protrusion 42.

[0080] When the immersion liquid is a phase change material, the thickness s1 of the first protrusion 41 can be less than the thickness s2 of the second protrusion 42. The thickness s1 of the first protrusion 41 can be 0.3 mm to 2 mm. For example, the thickness s1 of the first protrusion 41 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc. The thickness s2 of the second protrusion 42 can be 0.3 mm to 2 mm. For example, the thickness s2 of the second protrusion 42 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc.

[0081] Optionally, the thickness s2 of the second protrusion 42 may be 1.5 to 10 times the thickness s1 of the first protrusion 41. Since the thickness s1 of the first protrusion 41 is smaller, a greater number of first protrusions 41 may be provided on the top wall 10a of the housing 10, thereby providing a larger surface area. This, in turn, increases the contact area between the immersion liquid vapor and the first protrusions 41, thereby improving the heat exchange efficiency of evaporation and condensation.

[0082] In some embodiments, as Figure 6 As shown, the battery pack also includes a liquid cooling plate 50, which is arranged between the inner wall of the box body 10 and the heat exchange protrusion 40. The liquid cooling plate 50 includes a main body 51 and a liquid cooling interface 52 connected to the main body 51, and the liquid cooling interface 52 is connected to the outside of the box body 10.

[0083] When the immersion liquid is a single-phase immersion liquid or a phase change material, a liquid cooling plate 50 can be installed in the battery pack. The liquid cooling plate 50 can be installed between the inner wall of the housing 10 and the heat exchange protrusion 40. For example, the liquid cooling plate 50 can be installed between the top wall 10a of the housing 10 and the first protrusion 41; or, the liquid cooling plate 50 can be installed between the bottom wall 10c of the housing 10 and the second protrusion 42.

[0084] like Figure 6 As shown, the liquid cooling plate 50 includes a main body 51 and a liquid cooling interface 52. The main body 51 is plate-shaped and has channels within it for the flow of coolant. The liquid cooling interface 52 is used to connect to external equipment and supply circulating coolant to the main body 51. The liquid cooling interface 52 includes a liquid inlet and a liquid outlet. Coolant can flow from the liquid inlet into the main body 51 and then flow out from the liquid outlet.

[0085] The liquid inlet and outlet interfaces can be arranged on the same side of the main body 51 , so that the liquid inlet and outlet interfaces are more convenient to operate when connected to external pipes. The external pipes can be used to provide circulating coolant for the liquid cooling plate 50 .

[0086] In some embodiments, as Figure 6 As shown, the heat exchange protrusion 40 can be provided integrally with the liquid cooling plate 50. That is, a plurality of heat exchange protrusions 40 can be provided on the surface of the main body 51. With the above arrangement, the assembly process of the battery pack can be simplified.

[0087] In other embodiments, the liquid cooling plate 50 is integrally provided with the top wall 10a or the bottom wall 10c of the housing 10. This means that the liquid cooling plate 50 is provided at the top of the housing 10, serving as the top wall 10a of the housing 10; and / or the liquid cooling plate 50 is provided at the bottom of the housing 10, serving as the bottom wall 10c of the housing 10. This arrangement simplifies the assembly process of the battery pack.

[0088] In some embodiments, as Figure 2 and Figure 8 As shown, the battery module 20 includes a plurality of battery cells 21. For the convenience of explaining the structural member 22, Figure 8 Figure 2 shows two adjacent battery cells 21 after being disassembled and separated. A structural member 22 is provided between the two adjacent battery cells 21. The battery cell 21 includes a first side wall 211 and a second side wall 212. The area of ​​the first side wall 211 is larger than that of the second side wall 212. The structural member 22 is in contact with the first side wall 211.

[0089] The structural member 22 can be made of an elastic material, such as foam. By placing the structural member 22 between the battery cells 21, it can absorb dimensional tolerances of the battery cells 21. When the battery module 20 is assembled within the casing 10, the structural member 22 compresses to match the dimensions of the casing 10, reducing the machining precision requirements for the casing 10. Furthermore, the structural member 22 maintains the spacing between adjacent battery cells 21, allowing the space between adjacent battery cells 21 to be filled with immersion liquid, ensuring contact between the first sidewall 211 and the immersion liquid.

[0090] The battery cell 21 can be a square battery cell 21. The sidewalls of the battery cell 21 include a first sidewall 211 and a second sidewall 212 that are adjacent and connected. The area of ​​the first sidewall 211 is larger than the area of ​​the second sidewall 212. In other words, the first sidewall 211 is the large end surface of the battery cell 21, and the second sidewall 212 is the small end surface of the battery cell 21. The structural member 22 is disposed between the large end surfaces of two adjacent battery cells 21.

[0091] There may be two structural members 22, each in the form of an elongated plate. The long sides of the structural members 22 may extend along the height of the battery cells 21. The height of the battery cells 21 is the same as the height D1 of the housing 10. The structural member 22 has two opposing surfaces along the thickness direction, each of which contacts an adjacent first sidewall 211, thereby separating the two adjacent battery cells 21.

[0092] Alternatively, as Figure 3 As shown, the battery module 20 further includes end plates 23 , which are disposed at both ends of the battery module 20 . The end plates 23 can protect the battery cells 21 and prevent the battery cells 21 from being damaged by external collisions.

[0093] like Figure 3 As shown, a busbar 24 is further provided on the side of the battery cell 21 facing away from the bottom wall 10 c of the box body 10 , and the busbar 24 is used to achieve series and parallel connection of the multiple battery cells 21 .

[0094] In some embodiments, as Figure 9 As shown, a plurality of ribs 11 are provided on a surface of one side of the bottom wall 10 c of the box body 10 close to the battery module 20 . The ribs 11 extend in the same direction, and two adjacent ribs 11 are spaced apart.

[0095] The ribs 11 protrude from the bottom wall 10c of the housing 10. The ribs 11 extend along the longitudinal direction D2 of the housing 10, with flow channels formed between adjacent ribs 11. Because the immersion liquid is disturbed during heat exchange with the liquid cooling tubes 30, the ribs 11 allow the immersion liquid to flow along the flow channels formed between the ribs 11, thereby reducing disturbance of the immersion liquid.

[0096] It should be noted that when the liquid cooling plate 50 is disposed between the bottom wall 10 c of the box body 10 and the second protrusion 42 , the rib 11 on the bottom wall 10 c of the box body 10 may be omitted.

[0097] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery pack, characterized in that: include: A box (10), wherein a battery module (20) and an immersion liquid for immersing the battery module (20) are arranged in the box (10); The liquid cooling tube (30) comprises a liquid cooling body (31) arranged in the housing (10) and a liquid inlet nozzle (321) and a liquid outlet nozzle (322) connected to the liquid cooling body (31); the liquid cooling body (31) is in contact with the immersion liquid; the liquid inlet nozzle (321) and the liquid outlet nozzle (322) are connected to the outside of the housing (10); and the outer wall of the liquid cooling body (31) is provided with a plurality of protrusions (311).

2. The battery pack according to claim 1, wherein: The cross-sectional area of ​​the convex portion (311) away from the central axis of the liquid-cooling body (31) is smaller than the cross-sectional area of ​​the convex portion (311) close to the central axis of the liquid-cooling body (31).

3. The battery pack according to claim 2, wherein: The shape of the protrusion (311) includes a cone, a pyramid, a truncated cone, and a prism.

4. The battery pack according to claim 1, wherein: The liquid cooling tube (30) includes at least one of a first sub-tube (301) and a second sub-tube (302); the liquid cooling body (31) of the first sub-tube (301) is arranged between the side wall of the battery module (20) and the side wall (10b) of the box (10); and the liquid cooling body (31) of the second sub-tube (302) is arranged between the top surface of the battery module (20) and the top wall (10a) of the box (10).

5. The battery pack according to claim 4, characterized in that: The liquid inlet nozzle (321) and the liquid outlet nozzle (322) of each liquid cooling tube (30) are both arranged on the side wall of the same side of the box body (10).

6. The battery pack according to claim 4, characterized in that: The liquid cooling tube (30) includes at least the second sub-tube (302), the immersion liquid includes a phase change material, and at least part of the second sub-tube (302) is located between the liquid surface of the immersion liquid and the top wall (10a) of the box (10).

7. The battery pack according to any one of claims 1 to 6, characterized in that: The battery pack includes a plurality of heat exchange protrusions (40) arranged along the length direction of the box body (10) or the width direction of the box body (10), and two adjacent heat exchange protrusions (40) are arranged at intervals. The heat exchange protrusions (40) include a first protrusion (41) arranged between the top wall (10a) of the box body (10) and the battery module (20) and / or a second protrusion (42) arranged between the bottom wall (10c) of the box body (10) and the battery module (20), and the battery module (20) is arranged in contact with the heat exchange protrusions (40).

8. The battery pack according to claim 7, characterized in that: The battery pack comprises a first protrusion (41) and a second protrusion (42), wherein a thickness (s1) of the first protrusion (41) is less than or equal to a thickness (s2) of the second protrusion (42).

9. The battery pack according to claim 8, characterized in that: The thickness (s2) of the second protrusion (42) is 1.5 to 10 times the thickness (s1) of the first protrusion (41).

10. The battery pack according to claim 7, characterized in that: The battery pack further comprises a liquid cooling plate (50), the liquid cooling plate (50) being arranged between the inner wall of the box body (10) and the heat exchange protrusion (40), the liquid cooling plate (50) comprising a main body (51) and a liquid cooling interface (52) communicating with the main body (51), and the liquid cooling interface (52) communicating with the outside of the box body (10).

11. The battery pack according to claim 7, wherein: The battery pack further includes a liquid cooling plate (50), the liquid cooling plate (50) being integrally provided with the top wall (10a) of the box body (10) or the bottom wall (10c) of the box body (10), the liquid cooling plate (50) including a main body (51) and a liquid cooling interface (52) communicating with the main body (51), and the liquid cooling interface (52) communicating with the outside of the box body (10).

12. The battery pack according to claim 10 or 11, characterized in that: The liquid cooling plate (50) and the heat exchange protrusion (40) are integrally arranged.

13. The battery pack according to claim 7, wherein: The battery module (20) comprises a plurality of battery cells (21), a structural member (22) is provided between two adjacent battery cells (21), the battery cells (21) comprise adjacent first side walls (211) and second side walls (212), the area of ​​the first side walls (211) is greater than the area of ​​the second side walls (212), and the structural member (22) is in contact with the first side walls (211).

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