Cylindrical battery structure with central heat dissipation

Abstract

The utility model discloses a cylindrical battery structure with central heat dissipation, including shell, the upper portion of shell is equipped with the first opening of the convenience of loading into the roll core, be provided with the upper cover on the first opening, the shell has the bottom plate, be equipped with the second opening on the bottom plate, the roll core has the first center hole, still including the heat conduction needle of passing through the second opening and installing in the first center hole, the heat conduction needle has the second center hole of opening downward, be provided with temperature measuring element in the second center hole, the utility model has the beneficial effect for: setting temperature measuring element in the second center hole of heat conduction needle, can directly measure the roll core central region temperature, and do not increase the battery external size, make the heat management early warning of battery more accurate, and early warning thermal runaway, improve security greatly.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a cylindrical battery structure with central heat dissipation. Background Technology

[0002] Traditional cylindrical batteries rely on passive heat dissipation from the outside of the casing or on liquid cooling plates for heat dissipation. However, the central area of ​​the internal core is a "thermal island," where heat accumulates severely during charging and discharging, which can easily lead to electrolyte decomposition, thermal shrinkage of the separator, and even the risk of thermal runaway. In addition, existing temperature measurement methods mostly involve externally mounted thermal sensors or indirect temperature measurement via the tabs, which cannot directly obtain the true internal temperature of the core. The temperature measurement error is usually 5-10℃, making it difficult to accurately predict internal thermal anomalies.

[0003] For example, the patent application number "CN202411901589.2" discloses "a composite cylindrical battery thermal management system". Although it improves the heat dissipation effect of the battery, it still dissipates heat on the outside of the battery. During the use of the battery, the temperature inside the core cannot be measured, and the heat inside cannot be dissipated. Summary of the Invention

[0004] The purpose of this invention is to provide a cylindrical battery structure with central heat dissipation, which can not only measure the actual temperature inside the core, but also effectively dissipate the internal heat, thereby achieving efficient cooling of the battery.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A cylindrical battery structure with central heat dissipation includes a housing, a first opening on the upper part of the housing for easy insertion of a winding core, a top cover plate on the first opening, a bottom plate on the housing, a second opening on the bottom plate, and a first central hole on the winding core. It also includes a heat-conducting needle that passes through a second opening and is installed in a first central hole. The heat-conducting needle has a second central hole with the opening facing downwards, and a temperature sensing element is disposed in the second central hole.

[0006] Preferably, the inner diameter of the second central hole is not less than 1.5 mm.

[0007] Preferably, the depth to which the heat-conducting needle is inserted into the first central hole is not less than 1 / 2 of the depth of the first central hole.

[0008] Preferably, the end of the heat-conducting needle away from its opening is a closed end, and the closed end is hemispherical or conical in shape.

[0009] Preferably, the temperature sensing element is disposed inside the heat-conducting needle on the side near the closed end.

[0010] Preferably, the outer side of the lower part of the heat-conducting needle is welded and fixed to the base plate.

[0011] Preferably, the outer diameter of the heat-conducting needle is smaller than the inner diameter of the first central hole.

[0012] Preferably, the base plate has an annular groove on the outer side of the second opening, and the outer side of the lower part of the heat-conducting needle has an annular boss that can be accommodated in the annular groove.

[0013] Preferably, the inner diameter of the annular groove is greater than the outer diameter of the annular boss, and the inner diameter of the second opening is greater than the inner diameter of the first central hole.

[0014] Preferably, the surface of the heat-conducting needle is smooth and burr-free.

[0015] The beneficial effects of this utility model are as follows: 1. A temperature sensing element is installed in the second center hole of the heat-conducting needle, which can directly measure the temperature of the core area without increasing the external size of the battery. This makes the battery's thermal management warning more accurate and provides early warning of thermal runaway, greatly improving safety. When the battery experiences abnormalities such as internal short circuit, overcharging, or high-rate discharge, the core temperature will rise sharply before the surface temperature. If only surface temperature measurement is relied upon, the "early warning window of thermal runaway" may be missed, leading to the risk of fire and explosion. In addition, it can detect abnormal internal heating in the first instance, and the BMS (Battery Management System) can trigger protective measures such as cutting off charging and discharging for individual cells in advance, thus curbing thermal runaway from the source.

[0016] 2. As cylindrical batteries develop towards "high rate" and "large capacity", the internal heat density increases significantly, and the temperature difference between the center and the surface will further expand. The limitations and errors of traditional surface temperature measurement will be relatively large. This application directly inserts the heat-conducting needle into the core to conduct heat out of the core. When discharging at a rate greater than 6C, the internal temperature is 8-15℃ lower than that of the traditional structure, and the risk of thermal runaway is reduced by more than 40%.

[0017] 3. The depth to which the heat-conducting needle is inserted into the first center hole is not less than 1 / 2 of the depth of the first center hole, which can ensure that the temperature of the core center is discharged, and the temperature of the core center point can be detected during temperature measurement. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of Embodiment 1; Figure 2 This is a cross-sectional view of Example 2; Figure 3 for Figure 2 A magnified view of a section at point I.

[0019] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0020] The present invention will now be further described with reference to the accompanying drawings.

[0021] Example 1 like Figure 1 As shown, this embodiment of a cylindrical battery structure with central heat dissipation includes a housing 1. The housing 1 has a first opening at its upper part for easy insertion of a winding core 2. A top cover 3 is provided on the first opening. The housing 1 has a bottom plate 7, and the bottom plate 7 has a second opening for easy insertion of a heat-conducting needle 4. The winding core 2 has a first central hole 5 for accommodating the heat-conducting needle 4. The heat-conducting needle 4 passes through the second opening and is installed in the first central hole 5. The heat-conducting needle 4 has a second central hole 6 with its opening facing downwards. A temperature sensing element (not shown in the figure) is provided in the second central hole 6. The signal acquisition mode and connection method of this temperature sensing element are existing conventional technologies and will not be described in detail in this embodiment. The outer diameter of the heat-conducting needle 4 is smaller than the inner diameter of the first central hole 5, creating a clearance fit between them, facilitating the insertion of the heat-conducting needle 4 and reducing the risk of damaging the cylindrical winding core.

[0022] The inner diameter of the second central hole 6 is not less than 1.5mm. This size of hole can accommodate the insertion of temperature sensing elements and also facilitates the formation of a heat dissipation channel, making it easier to dissipate heat from inside the battery.

[0023] The other end (i.e., the upper end) of the heat-conducting needle 4 away from its opening is the closed end, which is shaped like a hemispherical head or a conical head, making it easy to insert into the first central hole 5.

[0024] The temperature sensing element is located inside the heat-conducting needle 4, near the sealed end. During actual installation, it can be placed close to the inside of the sealed end, combined with the following setting: the heat-conducting needle 4 is inserted into the first central hole 5 to a depth of 1 / 2 of the first central hole 5. This effectively allows the temperature sensing element to measure the temperature at the center of the battery (i.e., the middle section of the first central hole 5), ensuring that the temperature at the center of the core 2 is discharged, or, conversely, detecting the center temperature during temperature measurement.

[0025] In this embodiment, when processing the heat-conducting needle 4, it is necessary to ensure that its surface is smooth and free of burrs to avoid damaging the core. During assembly, first insert the core 2 along the first opening on the upper part of the outer shell 1 (ensuring that the first center hole 5 of the core 2 is aligned with the second opening of the base plate 7), and then install the upper cover plate 3 on the outer shell 1. After that, insert the heat-conducting needle 4 along the second opening into the first center hole 5, and then weld the outer side of the lower part of the heat-conducting needle 4 to the second opening of the base plate 7 for fixation.

[0026] This device incorporates a temperature sensing element within the second central hole of the heat-conducting needle, enabling direct measurement of the temperature in the central region of the winding core without increasing the external dimensions of the battery. This allows for more accurate thermal management and early warning of thermal runaway, significantly improving safety. By directly inserting the heat-conducting needle into the winding core, heat is dissipated from within the core. When discharging at a rate greater than 6C, the internal temperature is reduced by 8-15°C compared to traditional structures, lowering the risk of thermal runaway by more than 40%.

[0027] Example 2 In this embodiment, the main focus is on further designing the mounting structure of the heat-conducting pin 4 and the base plate 7. The structure of other parts is consistent with that in Embodiment 1, specifically as follows: like Figure 2 and Figure 3 As shown, the base plate 7 has an annular groove 101 on the outer side of the second opening 102, and an annular boss 401 that can be accommodated in the annular groove 101 is provided on the outer side of the lower part of the heat-conducting needle 4.

[0028] In use, the heat-conducting needle 4 passes through the second opening 102 and is inserted into the first central hole 5. The annular boss 401 is embedded in the annular groove 101, and the two are welded and sealed together. The inner diameter of the annular groove 101 is larger than the outer diameter of the annular boss 401, and the inner diameter of the second opening 102 is larger than the inner diameter of the first central hole 5. The reason for this limitation is that during actual production and assembly, the cylindrical core 2 is installed inside the outer casing 1, and there is a slight gap between it and the inner wall of the outer casing 1. It may not be completely coaxial and may have a certain error. Through the aforementioned limitation, the heat-conducting needle 4 has a certain radial movement space, which is conducive to accurate insertion into the first central hole 5 and avoids damage to the core 2 due to offset.

[0029] The above embodiments are not intended to limit the shape, material, structure, etc. of this utility model in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this utility model and to simplify the description, and do not 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 limiting the scope of protection of this utility model.

[0031] If the terms "first" or "second" are used in this document to define the components, those skilled in the art should know that the use of "first" or "second" is merely for the convenience of describing this utility model and simplifying the description, and unless otherwise stated, the above terms have no special meaning.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A cylindrical battery structure with central heat dissipation, comprising a housing, a first opening at the top of the housing for convenient insertion of a winding core, a top cover plate disposed on the first opening, and a bottom plate, characterized in that, The base plate has a second opening, and the core has a first center hole; It also includes a heat-conducting needle that passes through a second opening and is installed in a first central hole. The heat-conducting needle has a second central hole with the opening facing downwards, and a temperature sensing element is disposed in the second central hole.

2. The cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The inner diameter of the second central hole is not less than 1.5 mm.

3. The cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The depth to which the heat-conducting needle is inserted into the first central hole is not less than 1 / 2 of the depth of the first central hole.

4. The cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The end of the heat-conducting needle away from its opening is a closed end, and the closed end is shaped like a hemispherical head or a conical head.

5. A cylindrical battery structure with central heat dissipation according to claim 4, characterized in that, The temperature sensing element is located inside the heat-conducting needle on the side near the closed end.

6. A cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The outer side of the lower part of the heat-conducting needle is welded and fixed to the base plate.

7. A cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The outer diameter of the heat-conducting needle is smaller than the inner diameter of the first central hole.

8. A cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The base plate has an annular groove on the outside of the second opening, and the lower outer side of the heat-conducting needle has an annular boss that can be accommodated in the annular groove.

9. A cylindrical battery structure with central heat dissipation according to claim 8, characterized in that, The inner diameter of the annular groove is larger than the outer diameter of the annular boss, and the inner diameter of the second opening is larger than the inner diameter of the first central hole.

10. A cylindrical battery structure with central heat dissipation according to claim 1, characterized in that, The surface of the heat-conducting needle is smooth and burr-free.

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