Cylindrical battery and battery pack

Abstract

The application relates to the technical field of battery manufacturing, and provides a cylindrical battery and a battery pack. The cylindrical battery of the application comprises a battery cell, a current collecting disc and a pole; the battery cell, the current collecting disc and the pole are arranged in sequence along the height direction of the battery, the pole lug of the battery cell is connected with the current collecting disc, the current collecting disc and the pole are connected through a conductive connecting part, and the conductive connecting part is arranged close to the geometric center of the main body of the current collecting disc; when the current flowing through the conductive connecting part reaches a preset value K, the conductive connecting part is overheated and fused to disconnect the electrical connection between the battery cell and the pole. The cylindrical battery of the application can be fused when the current is too large, and the use safety of the cylindrical battery is improved.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a cylindrical battery and battery pack. Background Technology

[0002] With the rapid development of the lithium battery industry, cylindrical batteries have secured a significant position in the energy storage field due to their mature manufacturing processes and wide range of applications. Among them, large cylindrical batteries, compared to small cylindrical batteries, have become an important direction for current technological development because they possess higher energy density and help reduce the overall manufacturing cost of battery packs.

[0003] In the structural design of large cylindrical batteries, the positive electrode is typically equipped with a current collector, and a terminal post for current conduction is located at the center of the current collector. To ensure the overcurrent performance of the terminal post, the overcurrent capacity of the terminal post in existing technologies is often set higher than the normal overcurrent requirement. This not only meets the overcurrent requirements under normal battery operating conditions, but also maintains an overcurrent state even in abnormal operating scenarios such as short circuits. This design results in the battery being unable to effectively cut off the current when encountering abnormal operating conditions, thus adversely affecting the safety of cylindrical batteries and hindering the improvement of their operational safety. Utility Model Content

[0004] In view of this, this application aims to provide a cylindrical battery to improve the safety of using cylindrical batteries.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows: A cylindrical battery includes cells, current collectors, and terminals arranged sequentially along the height of the battery. The electrode of the battery cell is connected to the current collector, and the current collector and the electrode are connected by a conductive connection part, which is located close to the geometric center of the current collector body. When the current flowing through the conductive connection reaches a preset value K, the conductive connection overheats and melts, thereby disconnecting the electrical connection between the battery cell and the electrode.

[0006] Furthermore, the conductive connection portion includes a connecting post; one end of the connecting post is connected to the current collector, and the other end of the connecting post is connected to the electrode post.

[0007] Furthermore, along the height direction of the battery, the cross-sectional area S2 of the connecting post is smaller than the cross-sectional area S1 of the electrode post.

[0008] Furthermore, the cross-sectional area S2 of the connecting post and the cross-sectional area S1 of the electrode post satisfy the following condition: 2S2 < S1 < 2.5S2; and / or, along the height direction of the battery, the cross-sectional profile of the electrode post is circular, rectangular, or polygonal.

[0009] Furthermore, along the height direction of the battery, the height h2 of the connecting post and the height h1 of the electrode post satisfy the following condition: h1 < h2 < 1.2h1.

[0010] Furthermore, along the height direction of the battery, the cross-sectional profile of the electrode post is circular, and the cross-sectional profile of the electrode post gradually increases from top to bottom; along the height direction of the battery, the cross-sectional area S2 of the connecting post, the cross-sectional area S11 of the top end of the electrode post, and the cross-sectional area S12 of the bottom end of the electrode post satisfy the following relationship: S2 < S11 < S12.

[0011] Furthermore, the cross-sectional area S2 of the connecting post and the cross-sectional area S12 of the bottom end of the pole post satisfy the following condition: 2S2 < S12 < 3S2; and / or, the cross-sectional area S2 of the connecting post and the cross-sectional area S11 of the top end of the pole post satisfy the following condition: 1.3S2 < S11 < 1.8S2.

[0012] Furthermore, along the height direction of the battery, the height h2 of the connecting post and the height h1 of the electrode post satisfy the following condition: h1 < h2 < 1.3h1.

[0013] Furthermore, the connecting post, the pole post, and the collector plate are coaxially arranged; and / or, the preset value K satisfies: 600A≤K≤800A.

[0014] Compared with related technologies, this application has the following advantages: (1) The cylindrical battery described in this application can ensure the overcurrent capacity of the cylindrical battery under normal use by connecting the current collector and the terminal through the conductive connection. By making the conductive connection close to the geometric center of the current collector, the current conduction path is optimized, reducing the local overheating problem caused by uneven current distribution. Furthermore, by setting the conductive connection, when the current flowing through the conductive connection reaches a preset value K, it can melt and disconnect the electrical connection between the cell and the terminal, which helps to avoid the use of the cylindrical battery under abnormal conditions such as short circuit. This effectively avoids the risk of cell damage and thermal runaway caused by abnormal use, thereby helping to improve the safety of the cylindrical battery.

[0015] (2) By including a connecting post in the conductive connection part, and connecting the two ends of the connecting post to the current collector and the pole respectively, the column shape makes the cross-section consistent, which can ensure the conductivity stability during normal use and the reliability of the connecting post melting when it reaches the preset value K. The structure is simple, easy to process and manufacture, and conducive to design and implementation.

[0016] (3) By making the cross-sectional area S2 of the connecting column smaller than the cross-sectional area S1 of the pole column, it is ensured that the preset value K of the connecting column fuse is less than the fuse value of the pole column, which helps to ensure the over-current capacity of the cylindrical battery during normal use.

[0017] (4) By making the relationship between S2 and S1 satisfy: 2S2 < S1 < 2.5S2, it can not only ensure the structural strength of the connecting column and the pole column, avoid the risk of fracture caused by the too-thin connecting column, but also help to control the resistance difference between the connecting column and the pole column, so that the fusing specificity of the connecting column is stabilized within the preset range, avoid the situation that S2 is too large and the preset value K is too large and loses the meaning of short-circuit protection, and avoid the situation that S2 is too small and the preset value K is too small and affects the normal use of the cylindrical battery. At the same time, by setting the cross-sectional profile of the pole column in a simple geometric shape, it is convenient for processing and manufacturing.

[0018] (5) By making the relationship between the height h2 of the connecting column and the height h1 of the pole column satisfy: h1 < h2 < 1.2h1, by making the length of the connecting column greater than that of the pole column, it is convenient to increase the heating length of the connecting column when current passes through, which helps to optimize the fusing time of the connecting column. And the limitation of the height of the connecting column helps to avoid the overall structure being too high, improves the structural compactness of the cylindrical battery, and is convenient for design and implementation.

[0019] (6) By defining the pole column as a frustum shape, and the side with the larger area of the pole column faces the inside of the cylindrical battery, it is convenient to restrain the pole column on the cylindrical battery after the connecting column fuses, avoiding the risk of the pole column being ejected from the cylindrical battery, and making the area of the smaller surface of the pole column still larger than that of the connecting column, which helps to ensure that the fusing function is still reflected on the connecting column and guarantees the reliability of the protection function.

[0020] (7) By further defining the relationship between the cross-sectional area S2 of the connecting column and the cross-sectional area S12 at the bottom end of the pole column, the conductivity and structural strength of the pole column and the connecting column are guaranteed. At the same time, by further defining the relationship between the cross-sectional area S2 of the connecting column and the cross-sectional area S11 at the top end of the pole column, the fusing priority of the connecting column during abnormal current is ensured, which is convenient for design and implementation.

[0021] (8) By defining the relationship between the height h2 of the connecting column and the height h1 of the pole column, on the premise that the pole column is set as a frustum shape, the connection transition between the connecting column and the pole column is smoother, reducing the eddy current loss during current conduction, and guaranteeing the reliability of the connecting column heating and fusing, optimizing the fusing performance of the connecting column, which helps to design and implement.

[0022] (9) By making the connecting post, electrode post and current collector coaxial, the current conduction path is further optimized, avoiding local overheating caused by current deviation, and improving the concentricity of the assembly of each component, reducing mechanical stress concentration, and improving the structural stability of the cylindrical battery. At the same time, by making the preset value K satisfy: 600A≤K≤800A, the fusing current of the conductive connection is further optimized while ensuring the normal overcurrent capacity of the conductive connection, which is conducive to design implementation.

[0023] This application also proposes a battery pack comprising a cylindrical battery as described above.

[0024] The battery pack described in this application has the same beneficial effects as the cylindrical battery described above compared to the prior art, so it will not be described again here. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the cylindrical battery structure described in the embodiments of this application; Figure 2 This is a top view of one embodiment of the cylindrical battery described in this application. Figure 3 for Figure 2 Cross-sectional view at point AA; Figure 4 This is a schematic diagram of one embodiment of the terminal of the cylindrical battery described in this application. Figure 5 This is a side view of one embodiment of the terminal post of the cylindrical battery described in this application. Figure 6 This is a top view of another embodiment of the cylindrical battery described in this application. Figure 7 for Figure 6 Cross-sectional view of BB section; Figure 8 This is a schematic diagram of another embodiment of the terminal of the cylindrical battery described in this application. Figure 9 This is a side view of another embodiment of the terminal post of the cylindrical battery described in this application. Explanation of reference numerals in the attached figures: 1. Battery cell; 2. Current collector; 3. Terminal post; 4. Conductive connection part; 401. Connecting post; 5. Housing; 6. Conductive terminals; 7. Insulating components. Detailed Implementation

[0026] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0028] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying 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, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0030] In this application, 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 this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0032] The first aspect of this application provides a cylindrical battery that is used in a battery pack, mainly as an energy storage unit of the battery pack. The cylindrical battery of this embodiment, with its innovative structural design, can disconnect the connection between the terminal and the current collector in abnormal use conditions such as short circuits, thereby improving the safety of the cylindrical battery.

[0033] In related technologies, with the development of the lithium battery industry, large cylindrical batteries have been widely used because they have higher energy density than small cylindrical batteries, which can reduce the overall manufacturing cost of battery packs. In large cylindrical batteries, the positive electrode is usually equipped with a current collector, and the current collector usually has a current-conducting terminal. The side of the current collector away from the terminal is usually connected to the battery cell.

[0034] However, to ensure the overcurrent capability of the terminals, existing terminals are typically over-designed, not only meeting the overcurrent requirements under normal battery use but also maintaining an overcurrent state even in abnormal usage scenarios such as short circuits. This prevents the cylindrical battery from cutting off current transmission under abnormal conditions, adversely affecting the safety of cylindrical batteries and hindering the improvement of their operational safety.

[0035] In view of this, in order to overcome the shortcomings of related technologies, the cylindrical battery of this embodiment combines... Figures 1 to 5 As shown, the overall design includes battery cells, current collectors, and terminals.

[0036] The battery cells, current collectors, and terminals are arranged sequentially along the height of the battery. The tabs of the battery cells are connected to the current collectors, and the current collectors and terminals are connected by a conductive connection, which is located close to the geometric center of the current collector body. When the current flowing through the conductive connection reaches a preset value K, the conductive connection overheats and melts, thus breaking the electrical connection between the battery cells and terminals.

[0037] Therefore, by connecting the current collector and the terminal through a conductive connection, the overcurrent capacity of the cylindrical battery under normal use can be guaranteed. By placing the conductive connection close to the geometric center of the current collector, the current conduction path is optimized, reducing local overheating caused by uneven current distribution. Furthermore, the conductive connection allows the battery to melt and disconnect the electrical connection between the cell and the terminal when the current flowing through it reaches a preset value K. This helps to prevent the use of the cylindrical battery under abnormal conditions such as short circuits, effectively avoiding the risks of cell damage and thermal runaway caused by abnormal use, thus improving the safety of cylindrical batteries.

[0038] Based on the above general introduction, specifically, for the cylindrical battery in this embodiment, as shown in the figures, as an exemplary implementation, it generally includes a housing 5 and conductive terminals 6.

[0039] The housing 5 has a cavity for accommodating the battery cell 1. The current collector 2 is located on one side of the positive electrode of the battery cell 1. The electrode post 3 is located on the current collector 2 through the conductive connection part 4. The conductive terminal 6 is located on one side of the housing 5 and has a through hole. The end of the electrode post 3 extends into the through hole and is fixedly connected to the conductive terminal 6.

[0040] To better ensure the performance of the cylindrical battery, an insulating component 7 is provided between the conductive terminal 6 and the housing 5. The housing 5 has terminal mounting holes, the insulating component 7 covers the terminal mounting holes, and the conductive terminal 6 is assembled on the insulating component 7.

[0041] In specific implementations, the above-mentioned housing 5, conductive terminal 6 and insulating component 7 can refer to the relevant structures in existing cylindrical batteries, and will not be described in detail here.

[0042] It is worth mentioning that the preset value K of the conductive connection part 4 above needs to be designed according to the specific operating current of the cylindrical battery. It is only necessary to ensure that it meets the overcurrent capacity under normal use of the cylindrical battery and can cause the conductive connection part 4 to heat up and melt when the cylindrical battery is used abnormally.

[0043] In practical implementation, the above preset value K can be set based on the operating current of the cylindrical battery and experience. The preset value K can be set slightly less than the short-circuit current of the cylindrical battery to further reduce the risk caused by excessive current during abnormal use. For example, when the short-circuit current of the cylindrical battery reaches 900A, the preset value K can be set to 600A-800A. It needs to be set in combination with the specific operating current of the cylindrical battery to meet the normal use of the cylindrical battery.

[0044] Continue to combine Figures 1 to 5 As shown, in some exemplary embodiments, this example may include a conductive connection 4 including a connecting post 401, one end of which is connected to the current collector 2 and the other end of which is connected to the pole post 3.

[0045] It is understandable that by making the conductive connection part 4 include the connecting post 401, and the two ends of the connecting post 401 are respectively connected to the current collector 2 and the pole post 3, the column shape makes the cross-section consistent, which can ensure the conductivity stability during normal use, as well as the reliability of the connecting post 401 melting when it reaches the preset value K. The structure is simple, easy to process and manufacture, and conducive to design and implementation.

[0046] In practical implementation, the preset value K can be adjusted, for example, by adjusting the dimensions of the connecting post 401 (such as cross-sectional area and height). Of course, in addition to adjusting the dimensions of the connecting post 401, the preset value K can also be adjusted by changing the material of the connecting post 401.

[0047] Continue to combine Figures 1 to 5 As shown, in some exemplary embodiments, the conductive connection portion 4 includes a connecting post 401 as an example. In this embodiment, for example, the cross-sectional area S2 of the connecting post 401 along the height direction of the battery is smaller than the cross-sectional area S1 of the electrode post 3.

[0048] It is understandable that by making the cross-sectional area S2 of the connecting post 401 smaller than the cross-sectional area S1 of the electrode post 3, the preset value K of the connecting post 401 melting is less than the melting value of the electrode post 3, which helps to ensure the overcurrent capacity of the cylindrical battery during normal use.

[0049] Continue to combine Figures 1 to 5 As shown, in some exemplary embodiments, taking the example that the cross-sectional area S2 of the connecting post 401 is smaller than the cross-sectional area S1 of the pole post 3, this embodiment may, for example, satisfy the following condition between the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S1 of the pole post 3: 2S2<S1<2.5S2. Along the height direction of the battery, the cross-sectional profile of the pole post is circular, rectangular or polygonal.

[0050] It is understandable that by ensuring that S2 and S1 satisfy the condition 2S2 < S1 < 2.5S2, the structural strength of the connecting post 401 and the terminal post 3 can be guaranteed, avoiding the risk of breakage caused by the connecting post 401 being too thin. It also helps to control the resistance difference between the connecting post 401 and the terminal post 3, so that the fusing point of the connecting post 401 is kept within a preset range. This avoids S2 being too large, the preset value K being too large, which would result in the loss of short-circuit protection, and avoids S2 being too small, the preset value K being too small, which would affect the normal use of the cylindrical battery. At the same time, by setting the cross-sectional profile of the terminal post to have a simple geometric shape, it is easier to process and manufacture.

[0051] In practical implementation, the cross-sectional areas of the connecting column 401 and the pole column 3 are simple geometric shapes, and can be determined by calculating the area of ​​their end faces.

[0052] Continue to combine Figures 1 to 5 As shown, in some exemplary embodiments, the conductive connection part 4 includes the connecting post 401 as an example. In this embodiment, for example, the height h2 of the connecting post 401 and the height h1 of the electrode post 3 along the height direction of the battery can satisfy: h1 < h2 < 1.2h1.

[0053] It is understandable that by ensuring that the height h2 of the connecting post 401 and the height h1 of the electrode post 3 satisfy the condition h1 < h2 < 1.2h1, and by making the length of the connecting post 401 greater than that of the electrode post 3, it is easier to increase the heating length of the connecting post 401 when current flows through it. This helps to optimize the melting time of the connecting post 401. Furthermore, limiting the height of the connecting post 401 helps to avoid the overall structure being too tall, improves the structural compactness of the cylindrical battery, and facilitates design and implementation.

[0054] In specific implementation, the height h2 of the connecting post 401 refers to the distance between the top and bottom surfaces of the connecting post 401 along the height direction of the battery, and the height h1 of the electrode post 3 refers to the distance between the top and bottom surfaces of the electrode post 3 along the height direction of the battery.

[0055] Continue to combine Figure 1 ,as well as Figures 6 to 9 As shown, in some exemplary embodiments, still taking the conductive connection portion 4 including the connecting post 401 as an example, this embodiment may, for example, make the cross-sectional profile of the post 3 circular along the height direction of the battery, and the cross-sectional profile of the post 3 gradually increases from top to bottom.

[0056] Among them, along the height direction of the battery, the cross-sectional area S2 of the connecting post 401, the cross-sectional area S11 of the top end of the pole post 3, and the cross-sectional area S12 of the bottom end of the pole post 3 satisfy the following condition: S2 < S11 < S12.

[0057] Understandably, by defining the terminal post 3 as a frustum shape, with the larger side of the terminal post 3 facing the inside of the cylindrical battery, it is easier to constrain the terminal post 3 to the cylindrical battery after the connecting post 401 melts, thus avoiding the risk of the terminal post 3 being pushed out of the cylindrical battery. Furthermore, the smaller area of ​​the terminal post 3 is still larger than that of the connecting post 401, which helps to ensure that the melting function is still reflected in the connecting post 401, thus ensuring the reliability of the protection function.

[0058] In practical implementation, the shape of the through hole on the terminal matches the shape of the pole post 3 and is set as a tapered through hole. By limiting the shape of the pole post 3, it is easy to constrain the pole post 3 through the through hole on the terminal, which helps to constrain the pole post 3 on the cylindrical battery after the conductive connection part 4 melts.

[0059] In practical implementation, besides defining the pole post 3 as a frustum shape to facilitate its constraint on the terminal, a limiting structure can also be provided on the terminal to constrain the pole post 3. For example, a limiting claw can be provided on the terminal, and a limiting groove can be provided on the pole post 3. When the pole post 3 is assembled on the terminal, the limiting claw engages in the limiting groove. Of course, the above-mentioned limiting structure is difficult to manufacture, so this method was not used to limit the pole post 3 in this embodiment.

[0060] Continue to combine Figure 1 ,as well as Figures 6 to 9 As shown, in some exemplary embodiments, taking the pole post 3 as a frustum shape as an example, this embodiment may, for example, satisfy the following: 2S2 < S12 < 3S2 between the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S12 of the bottom end of the pole post 3; and 1.3S2 < S11 < 1.8S2 between the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S11 of the top end of the pole post 3.

[0061] It is understandable that by further limiting the relationship between the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S12 of the bottom end of the pole post 3, the conductivity and structural strength of the pole post 3 and the connecting post 401 are guaranteed. At the same time, by further limiting the relationship between the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S11 of the top end of the pole post 3, the fusing priority of the connecting post 401 in the event of an abnormal current is guaranteed, which facilitates design and implementation.

[0062] Continue to combine Figure 1 ,as well as Figures 6 to 9 As shown, in some exemplary embodiments, taking the pole post 3 as a frustum shape, this embodiment may, for example, make the height h2 of the connecting post 401 and the height h1 of the pole post 3 along the height direction of the battery satisfy: h1 < h2 < 1.3h1.

[0063] Understandably, by limiting the relationship between the height h2 of the connecting post 401 and the height h1 of the pole post 3, under the premise that the pole post 3 is set in a frustum shape, the connection transition between the connecting post 401 and the pole post 3 is made smoother, reducing eddy current losses during current conduction, ensuring the reliability of the connecting post 401's overheating and melting, optimizing the melting performance of the connecting post 401, and facilitating design and implementation.

[0064] In specific implementation, the height h2 of the connecting post 401 refers to the distance between the top and bottom surfaces of the connecting post 401 along the height direction of the battery, and the height h1 of the electrode post 3 refers to the distance between the top and bottom surfaces of the electrode post 3 along the height direction of the battery.

[0065] Continue to combine Figure 1 ,as well as Figures 6 to 9 As shown, in some exemplary embodiments, the conductive connection part 4 includes the connecting post 401 as an example. In this embodiment, the connecting post 401, the pole post 3 and the collector plate 2 can be arranged coaxially.

[0066] Understandably, by making the connecting post 401, the terminal post 3, and the current collector 2 coaxial, the current conduction path is further optimized, avoiding local overheating caused by current deviation, and improving the concentricity of the assembly of each component, reducing mechanical stress concentration, improving the structural stability of the cylindrical battery, and facilitating design implementation.

[0067] In practice, the connecting post 401 and the pole post 3 are both located on the same side of the current collector 2, and the other side of the current collector 2 is connected to the tab of the battery cell 1.

[0068] It is worth noting that, regarding the cylindrical battery of this embodiment, based on the above exemplary embodiments, in specific implementation, as a preferred embodiment, it is still... Figures 1 to 5 As shown, it generally includes a housing 5.

[0069] The casing 5 contains a battery cell 1, a current collector 2, and a terminal post 3 arranged sequentially along the height of the battery. The tabs of the battery cell 1 are connected to the current collector 2. The current collector 2 and the terminal post 3 are connected by a conductive connection part 4. The conductive connection part 4 includes a connecting post 401, the two ends of which are connected to the terminal post 3 and the current collector 2, respectively. The connecting post 401, the current collector 2, and the terminal post 3 are coaxially arranged.

[0070] The housing 5 has terminal mounting holes, and the terminal mounting holes are covered with insulating parts 7. The conductive terminals 6 are assembled on the insulating parts 7. The conductive terminals 6 have through holes, and the end of the pole post 3 extends into the through holes and is fixedly connected to the conductive terminals 6.

[0071] When the current flowing through the connecting post 401 reaches a preset value K, the connecting part overheats and melts, thus breaking the electrical connection between the battery cell 1 and the electrode post 3. The electrode post 3 is cylindrical, and the cross-sectional area S2 of the connecting post 401 and the cross-sectional area S1 of the electrode post 3 satisfy the following condition: 2S2 < S1 < 2.5S2. The height h2 of the connecting post 401 and the height h1 of the electrode post 3 satisfy the following condition: h1 < h2 < 1.2h1.

[0072] It is worth noting that, regarding the cylindrical battery of this embodiment, based on the above exemplary embodiments, in specific implementation, as another preferred embodiment, it is still... Figure 1 ,as well as Figures 6 to 9 As shown, it generally includes a housing 5.

[0073] The casing 5 contains a battery cell 1, a current collector 2, and a terminal post 3 arranged sequentially along the height of the battery. The tabs of the battery cell 1 are connected to the current collector 2. The current collector 2 and the terminal post 3 are connected by a conductive connection part 4. The conductive connection part 4 includes a connecting post 401, the two ends of which are connected to the terminal post 3 and the current collector 2, respectively. The connecting post 401, the current collector 2, and the terminal post 3 are coaxially arranged.

[0074] The housing 5 has terminal mounting holes, and the terminal mounting holes are covered with insulating parts 7. The conductive terminals 6 are assembled on the insulating parts 7. The conductive terminals 6 have through holes, and the end of the pole post 3 extends into the through holes and is fixedly connected to the conductive terminals 6.

[0075] When the current flowing through the connecting post 401 reaches a preset value K, the connecting part overheats and melts, thus breaking the electrical connection between the battery cell 1 and the electrode post 3. The electrode post 3 is frustum-shaped, and the cross-sectional area S2 of the connecting post 401 and the cross-sectional areas S11 at the top and S12 at the bottom of the electrode post 3 satisfy the following relationship: 2S2 < S12 < 3S2, 1.3S2 < S11 < 1.8S2. The height h2 of the connecting post 401 and the height h1 of the electrode post 3 satisfy the following relationship: h1 < h2 < 1.3h1.

[0076] In the preferred embodiment of the cylindrical battery described above, the specific configuration and arrangement of the cell 1, current collector 2, connecting post 401 and terminal post 3, etc., can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the cell 1, current collector 2, connecting post 401 and terminal post 3, etc., can also be referred to the descriptions in the above exemplary embodiments.

[0077] The cylindrical battery of this embodiment adopts the above design. By connecting the current collector 2 and the terminal 3 through the conductive connection part 4, the overcurrent capacity of the cylindrical battery under normal use can be guaranteed. By placing the conductive connection part 4 close to the geometric center of the current collector 2, the current conduction path is optimized, reducing the local overheating problem caused by uneven current distribution. Furthermore, by setting the conductive connection part 4, when the current flowing through the conductive connection part 4 reaches a preset value K, it can melt and disconnect the electrical connection between the cell 1 and the terminal 3. This helps to avoid the use of the cylindrical battery under abnormal conditions such as short circuits, effectively avoiding the risks of cell 1 damage and thermal runaway caused by abnormal use, thereby helping to improve the safety of the cylindrical battery.

[0078] An embodiment of the second aspect of this application provides a battery pack comprising cylindrical batteries as described above.

[0079] In the battery pack of this embodiment, the cylindrical battery serves as an energy storage unit and is generally connected to the battery management system within the battery pack. The connection method between the cylindrical battery and the battery management system can be referenced from existing connection methods in battery packs (such as wiring harness connections), and will not be elaborated further here.

[0080] The vehicle in this embodiment uses a cylindrical battery as described above, and through the provision of the conductive connection part 4, it can melt and disconnect the electrical connection between the cell 1 and the terminal 3 when the current flowing through the conductive connection part 4 reaches a preset value K. This helps to avoid the use of the cylindrical battery under abnormal conditions such as short circuits, effectively avoiding the risks of cell 1 damage and thermal runaway caused by abnormal use, thereby helping to improve the safety of cylindrical battery use.

[0081] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A cylindrical battery, characterized in that: This includes the battery cells, current collectors, and terminals arranged sequentially along the height of the battery. The electrode of the battery cell is connected to the current collector, and the current collector and the electrode are connected by a conductive connection part, which is located close to the geometric center of the current collector body. When the current flowing through the conductive connection reaches a preset value K, the conductive connection overheats and melts, thereby disconnecting the electrical connection between the battery cell and the electrode.

2. The cylindrical battery according to claim 1, characterized in that: The conductive connection portion includes a connecting post; One end of the connecting post is connected to the collector plate, and the other end of the connecting post is connected to the pole post.

3. The cylindrical battery according to claim 2, characterized in that: Along the height direction of the battery, the cross-sectional area S2 of the connecting post is smaller than the cross-sectional area S1 of the electrode post.

4. The cylindrical battery according to claim 3, characterized in that: The cross-sectional area S2 of the connecting post and the cross-sectional area S1 of the pole post satisfy the following condition: 2S2 < S1 < 2.5S2; and / or, Along the height direction of the battery, the cross-sectional profile of the electrode post is circular, rectangular, or polygonal.

5. The cylindrical battery according to claim 2, characterized in that: Along the height direction of the battery, the height h2 of the connecting post and the height h1 of the electrode post satisfy the following condition: h1 < h2 < 1.2h1.

6. The cylindrical battery according to claim 2, characterized in that: Along the height direction of the battery, the cross-sectional profile of the electrode post is circular, and the cross-sectional profile of the electrode post gradually increases from top to bottom. Along the height direction of the battery, the cross-sectional area S2 of the connecting post, the cross-sectional area S11 of the top end of the electrode post, and the cross-sectional area S12 of the bottom end of the electrode post satisfy the following relationship: S2 < S11 < S12.

7. The cylindrical battery according to claim 6, characterized in that: The cross-sectional area S2 of the connecting column and the cross-sectional area S12 of the bottom end of the pole column satisfy the following condition: 2S2 < S12 < 3S2; and / or, The cross-sectional area S2 of the connecting post and the cross-sectional area S11 of the top of the pole post satisfy the following condition: 1.3S2 < S11 < 1.8S2.

8. The cylindrical battery according to claim 6, characterized in that: Along the height direction of the battery, the height h2 of the connecting post and the height h1 of the electrode post satisfy the following condition: h1 < h2 < 1.3h1.

9. The cylindrical battery according to any one of claims 2 to 8, characterized in that: The connecting post, the pole post, and the collector plate are coaxially arranged; and / or, The preset value K satisfies: 600A≤K≤800A.

10. A battery pack, characterized in that: The cylindrical battery includes any one of claims 1 to 9.

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