Cylindrical battery and cylindrical battery thermal management system

Abstract

The embodiment of the invention provides a cylindrical battery and a thermal management system of the cylindrical battery, the cylindrical battery comprises a shell and a battery cell, the shell comprises a peripheral shell, a bottom shell and an end cover, and the bottom shell and the end cover are respectively connected to two ends of the peripheral shell in the axial direction; the battery cell is arranged in the shell, and an inner pipe which is arranged in the axial direction of the battery cell and penetrates through the interior of the battery cell is connected between the bottom shell and the end cover; and the inner pipe is used for being communicated with an external cooling pipeline or allowing the external cooling pipeline to penetrate through. According to the cylindrical battery disclosed by the invention, heat in the battery cell can be directly taken away by utilizing the cooling pipeline which is communicated with the inner pipe or penetrates through the inner pipe, so that accurate adjustment of the temperature in the cylindrical battery is realized, the problem of difficulty in heat exchange in a large-size cylindrical battery is solved, the performance and the safety of the battery are improved, and the limitation of an internal heat dissipation section on the size of the cylindrical battery is relieved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a cylindrical battery and a thermal management system for the cylindrical battery. Background Technology

[0002] Currently, there are three main cell designs for power batteries: pouch, prismatic, and cylindrical, which can meet the different requirements of battery systems for energy density, discharge power, and charging speed. With the continuous development of PACK integration solutions towards CTP and CTC, the cylindrical battery solution led by Tesla is gaining increasing industry recognition and adoption. Cylindrical batteries are also developing towards larger sizes, and this battery system solution has shown significant advantages in energy density, discharge power, and safety.

[0003] As the size of cylindrical batteries increases, internal heat exchange becomes more difficult, affecting the core temperature of the cell. Excessively high core temperatures can limit battery performance and safety. Currently, common cooling solutions are side or bottom cooling, but neither of these methods can guarantee efficient and precise temperature control within the cell, thus limiting further increases in the size of cylindrical batteries. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a cylindrical battery. This cylindrical battery has an inner tube inside its casing that can communicate with or allow cooling pipes to pass through, directly removing heat from the cell's interior. This enables precise temperature regulation of the cylindrical battery's internal structure, solving the problem of difficult heat exchange inside large-size cylindrical batteries, improving battery performance and safety, and removing the size limitation imposed by internal heat dissipation bottlenecks on the cylindrical battery.

[0005] Embodiments of the present invention also propose a thermal management system for cylindrical batteries.

[0006] The cylindrical battery of this invention includes a casing and a cell. The casing includes an outer shell and a bottom shell and an end cap respectively connected to the two ends of the outer shell along the axial direction. The cell is disposed inside the casing, and an inner tube is connected between the bottom shell and the end cap, which is arranged along the axial direction of the cell and passes through the inside of the cell. The inner tube is used to connect to an external cooling pipe or to allow an external cooling pipe to pass through.

[0007] The cylindrical battery of this invention includes an outer shell and a bottom shell and an end cap respectively connected to both ends of the outer shell. The battery cell is disposed inside the shell, and an inner tube arranged along the axial direction of the battery cell is connected between the bottom shell and the end cap. The inner tube is used to connect to or allow external cooling pipes to pass through. Thus, the cooling pipes connected to or passing through the inner tube can directly remove the heat inside the battery cell, thereby achieving precise regulation of the internal temperature of the cylindrical battery, solving the problem of difficult heat exchange inside large-size cylindrical batteries, improving battery performance and safety, and removing the limitation of internal heat dissipation on the size of cylindrical batteries.

[0008] In some embodiments, the central axis of the inner tube is collinear with the central axis of the battery cell.

[0009] In some embodiments, if the diameter of the inner tube is d and the diameter of the bottom shell is D, then 0.1 ≤ d / D ≤ 0.4 is satisfied.

[0010] In some embodiments, the bottom shell is provided with a first opening, the end cap is provided with a second opening, and the two ends of the inner tube are respectively connected to the first opening and the second opening.

[0011] In some embodiments, the inner tube includes a first segment communicating with the first opening and a second segment communicating with the second opening, as well as an intermediate segment connecting the first segment and the second segment, wherein the cross-sectional area of ​​the first segment and / or the second segment gradually increases in the direction away from the intermediate segment.

[0012] In some embodiments, the bottom shell is provided with a first opening, the end cap is provided with a second opening, and the two ends of the inner tube pass through the first opening and the second opening, respectively.

[0013] In some embodiments, the inner tube has sealing protrusions at both ends in the axial direction, the sealing protrusions being arranged around the outer circumferential surface of the inner tube and protruding outwards from the radial direction of the inner tube.

[0014] In some embodiments, there are multiple sealing protrusions, and the multiple sealing protrusions are arranged at intervals along the length direction of the inner tube.

[0015] In some embodiments, the inner tube is a circular tube;

[0016] And / or, the bottom shell, the inner tube, and the outer peripheral shell are integrally formed.

[0017] The cylindrical battery thermal management system of this invention includes a cooling assembly and a cylindrical battery as described in the above embodiments, wherein the cooling assembly includes cooling pipes.

[0018] The cylindrical battery thermal management system of this invention, by using the above-mentioned cylindrical battery, allows the cooling pipes connected to or passing through the inner tube to directly remove heat from the inside of the cell, thereby achieving precise regulation of the internal temperature of the cylindrical battery, solving the problem of difficult internal heat exchange in large-size cylindrical batteries, improving battery performance and safety, and removing the limitation of internal heat dissipation on the size of the cylindrical battery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a cylindrical battery according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a cylindrical battery according to another embodiment of the present invention.

[0021] Figure 3 This is a cross-sectional view of a cylindrical battery according to an embodiment of the present invention.

[0022] Figure label:

[0023] 1. Housing, 11. Bottom shell, 12. Outer shell, 13. End cap, 2. Battery cell, 3. Inner tube, 4. Cooling pipe, 5. Sealing insulation layer. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] The following is for reference. Figures 1-3 A cylindrical battery according to an embodiment of the present invention.

[0026] like Figures 1-3 As shown, the cylindrical battery of this embodiment includes a housing 1 and a cell 2. The housing 1 includes an outer shell 12 and a bottom shell 11 and an end cap 13 respectively connected to the two ends of the outer shell 12 along the axial direction. The cell 2 is disposed inside the housing 1, and an inner tube 3 is connected between the bottom shell 11 and the end cap 13, which is arranged along the axial direction of the cell 2 and passes through the inside of the cell 2. The inner tube 3 is used to connect to an external cooling pipe 4 or to allow the external cooling pipe 4 to pass through.

[0027] In other words, compared to conventional cylindrical batteries, this application adds an inner tube 3 inside the casing 1, and the battery cell 2 is located between the inner tube 3 and the outer casing 12. Since the inner tube 3 is inside the battery cell 2 as a whole, when the inner tube 3 is connected to the external cooling pipe 4 or when the external cooling pipe 4 passes through it, the cooling medium in the cooling pipe 4 can directly carry away the heat inside the battery cell 2, thereby precisely controlling the temperature inside the battery cell 2.

[0028] The cylindrical battery of this invention has a housing 1 including an outer peripheral shell 12 and a bottom shell 11 and an end cap 13 respectively connected to the two ends of the outer peripheral shell 12. The battery cell 2 is disposed inside the housing 1, and an inner tube 3 is connected between the bottom shell 11 and the end cap 13 along the axial direction of the battery cell 2. The inner tube 3 is used to connect to an external cooling pipe 4 or to allow the external cooling pipe 4 to pass through. Thus, the cooling pipe 4 connected to or passing through the inner tube 3 can directly remove the heat inside the battery cell 2, realize the precise regulation of the internal temperature of the cylindrical battery, solve the problem of difficult heat exchange inside large-size cylindrical batteries, improve battery performance and safety, and remove the limitation of internal heat dissipation on the size of the cylindrical battery.

[0029] Optionally, such as Figure 1 and Figure 2 As shown, the central axis of the inner tube 3 is collinear with the central axis of the cell 2. It is understandable that the closer to the center of the cell 2, the more difficult the heat exchange. Setting the inner tube 3 coaxially with the cell 2 allows the inner tube 3 to be positioned precisely in the center of the cell 2, further improving the heat dissipation effect in the middle position. Secondly, the cell 2 of a cylindrical battery is usually a wound core; setting the inner tube 3 coaxially with the cell 2 facilitates the alignment of the inner tube 3 with the center hole of the wound core, without interfering with the normal structure of the wound core.

[0030] Furthermore, if the diameter of the inner tube 3 is d and the diameter of the bottom shell 11 is D, then 0.1 ≤ d / D ≤ 0.4 is satisfied. It should be noted that the larger the diameter of the inner tube 3, the greater the allowable flow rate of the cooling medium, and correspondingly, the better the heat dissipation effect inside the battery cell 2. However, a larger diameter of the inner tube 3 will also reduce the effective assembly space of the battery cell 2. Therefore, the size of the inner tube 3 diameter should take into account both heat dissipation and the rationality of the battery cell 2 assembly space layout. The inventors have found through research that when the ratio of the diameter of the inner tube 3 to the diameter of the bottom shell 11 is between 0.1 and 0.4, it can satisfy the heat dissipation effect while ensuring that the battery cell 2 has sufficient assembly space. Specifically, the ratio can be determined based on the actual size and performance requirements of the cylindrical battery. For example, when the cylindrical battery is relatively small, its internal heat dissipation does not require a large flow of cooling medium, so the ratio of the diameter of the inner tube 3 to the diameter of the bottom shell 11 can be set to 0.1. The inner tube 3 occupies less space, and the reserved space for the assembly of the battery cell 2 is larger. However, when the cylindrical battery is large, its internal heat dissipation requires a larger flow of cooling medium, so the ratio of the diameter of the inner tube 3 to the diameter of the bottom shell 11 can be set to 0.4. The inner tube 3 occupies more space, allowing a larger flow of cooling medium to pass through to meet the heat dissipation requirements. Moreover, since the cylindrical battery is large, the relatively large diameter of the inner tube 3 will not cause insufficient space for the assembly of the battery cell 2 due to space occupation.

[0031] Furthermore, taking a common type of cylindrical battery as an example, the diameter of cell 2 is between 18-100mm and the length is between 50-300mm. Preferably, the diameter of cell 2 is between 50-80mm and the length is between 70-150mm; the diameter of inner tube 3 is between 1-20mm, preferably 3-10mm.

[0032] Optionally, such as Figure 1 and Figure 3 As shown, the bottom shell 11 has a first opening, and the end cap 13 has a second opening. The two ends of the inner tube 3 are connected to the first opening and the second opening, respectively. In other words, the openings at both ends of the inner tube 3 are formed on the bottom shell 11 and the end cap, respectively. In this embodiment, the cooling pipe 4 can pass through the inner tube 3.

[0033] Preferably, the inner tube 3 includes a first section communicating with the first opening, a second section communicating with the second opening, and an intermediate section connecting the first and second sections. The cross-sectional area of ​​the first and / or second sections gradually increases in the direction away from the intermediate section. Thus, the end of the inner tube 3 is designed as a gradually tapering cone, which can guide the installation of the cooling pipe 4 and improve the ease of assembly.

[0034] In other implementations, such as Figure 2 As shown, the bottom shell 11 has a first opening, and the end cap 13 has a second opening. The two ends of the inner tube 3 pass through the first opening and the second opening, respectively. In other words, the two ends of the inner tube 3 protrude outward to form a plug-in connector, so that the cooling pipe 4 can be plugged into the plug-in connector, and the cooling medium flows directly along the inner tube 3, resulting in better heat exchange.

[0035] Preferably, the inner tube 3 has sealing protrusions (not shown) at both ends in the axial direction. The sealing protrusions are arranged on the outer circumferential surface of the inner tube 3 and protrude radially outward from the inner tube 3. Thus, the sealing protrusions can seal and prevent dislodgement of the insertion fit between the cooling pipe 4 and the inner tube 3, avoid leakage, and improve the reliability of the assembly.

[0036] Preferably, there are multiple sealing protrusions, which are spaced apart along the length of the inner tube 3. This allows the multiple sealing protrusions to form a multi-layered seal, further improving the sealing effect.

[0037] Preferably, the inner tube 3 is a circular tube. It can be understood that the cell 2 of the cylindrical battery is a winding core, and the inner hole of the winding core is a circular hole. The inner tube 3 is constructed as a circular tube to facilitate its fit with the inner wall of the winding core. At the same time, the circular tube occupies less space under the same flow cross section.

[0038] Alternatively, the inner tube 3 can also be square, oval, or triangular, etc., without limitation.

[0039] Preferably, the bottom shell 11, the inner tube 3, and the outer peripheral shell 12 are integrally formed, resulting in high structural strength, high connection reliability, and good sealing effect.

[0040] Furthermore, a sealing insulation layer 5 is provided between the end cap 13 and the outer peripheral shell 12 to prevent short circuits in the cylindrical battery.

[0041] The cylindrical battery thermal management system of this invention includes a cooling assembly and the cylindrical battery described in the above embodiment. The cooling assembly includes a cooling pipe 4, which passes through or connects to the inner tube 3.

[0042] The cylindrical battery thermal management system of this invention, by using the above-mentioned cylindrical battery, allows the cooling pipe 4, which is connected to or passes through the inner tube 3, to directly remove the heat inside the cell 2, thereby achieving precise regulation of the internal temperature of the cylindrical battery, solving the problem of difficult internal heat exchange in large-size cylindrical batteries, improving battery performance and safety, and removing the limitation of internal heat dissipation on the size of the cylindrical battery.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A cylindrical battery, characterized by comprising: The cylindrical battery comprises a shell and an electric core, the shell comprises an outer shell and a bottom shell and an end cover connected to two ends of the outer shell in the axial direction respectively, the electric core is arranged in the shell, and an inner tube is connected between the bottom shell and the end cover in the axial direction of the electric core and penetrates the inside of the electric core, and the inner tube is used for connecting or penetrating the external cooling pipeline.

2. The cylindrical battery according to claim 1, characterized by The central axis of the inner tube is collinear with the central axis of the electric core.

3. The cylindrical battery according to claim 1, characterized by, The diameter of the inner tube is d, the diameter of the bottom shell is D, and 0.1≤d / D≤0.4 is satisfied.

4. The cylindrical battery according to claim 1, characterized by, The bottom shell is provided with a first opening, the end cover is provided with a second opening, and the two ends of the inner tube are connected to the first opening and the second opening respectively.

5. The cylindrical battery according to claim 4, characterized by The inner tube comprises a first section connected to the first opening, a second section connected to the second opening, and an intermediate section connected between the first section and the second section, and the cross-sectional area of the first section and / or the second section gradually increases in the direction away from the intermediate section.

6. The cylindrical battery according to claim 1, characterized by, The bottom shell is provided with a first opening, the end cover is provided with a second opening, and the two ends of the inner tube are connected to the first opening and the second opening respectively.

7. The cylindrical battery according to claim 6, characterized by The inner tube is provided with a sealing protrusion at both ends in the axial direction, the sealing protrusion is annularly arranged on the outer circumferential surface of the inner tube and protrudes outward in the radial direction of the inner tube.

8. The cylindrical battery according to claim 7, characterized by The sealing protrusion is a plurality of sealing protrusions, and the plurality of sealing protrusions are arranged at intervals along the length direction of the inner tube.

9. The cylindrical battery according to claim 1, characterized by, The inner tube is a circular tube. And / or, the bottom shell, the inner tube and the outer shell are integrally formed.

10. A system for thermal management of a cylindrical battery, the system comprising: The cylindrical battery comprises a cooling assembly and a cylindrical battery according to any one of claims 1-9, and the cooling assembly comprises a cooling pipeline.

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