Cylindrical battery and battery pack

Abstract

Provided in the present application are a cylindrical battery and a battery pack. The cylindrical battery comprises a case and a cell arranged in the case, wherein the cell comprises a first tab and a second tab, which are both located on the same side of the cell and have opposite polarities; the case comprises a circumferential side wall, and a first end wall and a second end wall which are located at two ends of the circumferential side wall; and a terminal assembly is provided on the first end wall, a first output terminal is provided on the case of the cylindrical battery, a second output terminal is provided on the first end wall, and a first insulation layer and a second insulation layer are provided on the outer peripheral surface of the cell. During the use of the cylindrical battery, significant heat is generated at the connections of the first tab and the second tab with the terminal assembly. The first insulation layer has a high heat deflection temperature, and can thus withstand the high temperature at the connections, so as to prevent the first insulation layer from melting at high temperature and thus detaching from the cell.

Description

Cylindrical batteries and battery packs

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411436067.X, filed on October 15, 2024, entitled “Cylindrical Battery and Battery Pack”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of new energy battery technology, specifically to a cylindrical battery and battery pack. Background Technology

[0004] The battery pack is a key component of new energy vehicles, and it contains multiple batteries. Each battery includes a cell, and each cell includes tabs. These tabs are welded to terminals on the end cap, allowing the cell to connect to external electrical devices. Furthermore, to ensure the insulation performance of the cells, they are covered with an insulating film.

[0005] During battery use, current flows through the terminals and tabs. Since both are made of metal, significant heat is generated in the area where the terminals and tabs connect. The insulating film located near this area may melt due to the high temperature, causing it to detach from the battery cell and affecting normal battery operation. Summary of the Invention

[0006] Therefore, the technical problem to be solved by this application is to overcome the defect that the insulating film near the connection area between the tab and the terminal in the battery is easily affected by high temperature during use, thereby providing a cylindrical battery and battery pack.

[0007] To address the aforementioned issues, this application provides a cylindrical battery, comprising a casing and a cell disposed within the casing. The cell includes a first tab and a second tab, both located on the same side of the cell, and having opposite polarities. The casing includes a circumferential sidewall and a first endwall and a second endwall located at opposite ends of the circumferential sidewall. A terminal assembly is disposed on the first endwall. A first output electrode is disposed on the casing of the cylindrical battery, and a second output electrode is disposed on the first endwall. A first insulating layer and a second insulating layer are disposed on the outer circumferential surface of the cell. The first insulating layer is disposed close to the first endwall, and the second insulating layer is located on the side of the first insulating layer opposite to the first endwall. Furthermore, the heat distortion temperature of the first insulating layer is greater than that of the second insulating layer.

[0008] Optionally, the heat distortion temperature of the first insulating layer is in the range of 220-280°C; and / or, the heat distortion temperature of the second insulating layer is in the range of 100-150°C.

[0009] Optionally, the housing serves as the first output electrode, the pole assembly serves as the second output electrode, and the first and second tabs are electrically connected to the housing and the pole assembly, respectively.

[0010] Optionally, along the axial direction of the cell, the distance between the edge of the first insulating layer facing the first end wall and the first end wall is in the range of 0 to 4 mm.

[0011] Optionally, the size of the first insulating layer is smaller than the size of the second insulating layer along the axial direction of the battery cell.

[0012] Optionally, along the axial direction of the cell, the ratio of the size of the first insulating layer to the size of the second insulating layer is in the range of 0.04 to 0.21.

[0013] Optionally, when the radius of the cylindrical battery is greater than or equal to 40 mm, the ratio of the size of the first insulating layer to the size of the second insulating layer is in the range of 0.06 to 0.18.

[0014] Optionally, the size of the first insulating layer along the axial direction of the cell is in the range of 8 mm to 18 mm.

[0015] Optionally, there is an overlap between the first insulating layer and the second insulating layer, and the size of the overlap is in the range of 0 to 4 mm along the axial direction of the cell.

[0016] Optionally, when the ratio of the area of ​​the first electrode end face to the area of ​​the second electrode end face is in the range of 0.5 to 1, the distance from the edge of the overlapping portion near the first end wall to the first end wall is in the range of 10 mm to 18 mm.

[0017] Optionally, the ratio of the thickness of the first insulating layer to the thickness of the second insulating layer is in the range of 0.6 to 1.2.

[0018] This application also provides a battery pack, including the cylindrical battery described above.

[0019] This application has the following advantages:

[0020] Using the technical solution of this application, a first insulating layer and a second insulating layer are disposed on the outer peripheral surface of the battery cell, with the first insulating layer positioned close to the terminal assembly. During the use of a cylindrical battery, the terminal assembly generates significant heat, while the first insulating layer has a high heat distortion temperature, thus able to withstand the high temperatures at the connection point and preventing the first insulating layer from melting and detaching from the battery cell. The second insulating layer is less affected by high temperatures, therefore its heat distortion temperature is relatively low, ensuring good heat dissipation and preventing high heat accumulation on the battery cell surface. Therefore, the technical solution of this application solves the defect in the prior art where the insulating film near the connection area between the tabs and terminals is easily affected by high temperatures during battery use. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 shows a schematic diagram of the cylindrical battery structure of this application;

[0023] Figure 2 shows a schematic diagram of the first end wall and cell structure of the cylindrical battery in Figure 1;

[0024] Figure 3 shows a front view of the first end wall and the cell in Figure 2;

[0025] Figure 4 shows a schematic diagram of the first and second insulating layers of the battery cell in Figure 2 having an overlapping portion.

[0026] Explanation of reference numerals in the attached drawings: 10, housing; 20, battery cell; 11, circumferential sidewall; 12, first end wall; 13, second end wall; 14, pole assembly; 30, first insulating layer; 40, second insulating layer; 50, overlapping portion. Detailed Implementation

[0027] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 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. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 according to the specific circumstances.

[0030] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0031] As shown in Figures 1 to 3, an embodiment of the cylindrical battery according to this application includes a housing 10 and a battery cell 20 disposed within the housing 10. The battery cell 20 includes a first tab and a second tab, both located on the same side of the cell 20, and having opposite polarities. The housing 10 includes a circumferential sidewall 11 and a first endwall 12 and a second endwall 13 located at both ends of the circumferential sidewall 11. A terminal assembly 14 is disposed on the first endwall 12. A first output stage is disposed on the housing 10 of the cylindrical battery, and a second output stage is disposed on the first endwall 12.

[0032] Furthermore, a first insulating layer 30 and a second insulating layer 40 are provided on the outer peripheral surface of the battery cell 20. The first insulating layer 30 is disposed close to the first end wall 12, and the second insulating layer 40 is located on the side of the first insulating layer 30 away from the first end wall 12. The heat deformation temperature of the first insulating layer 30 is greater than that of the second insulating layer 40.

[0033] Using the technical solution of this embodiment, a first insulating layer 30 and a second insulating layer 40 are provided on the outer peripheral surface of the battery cell 20, with the first insulating layer 30 positioned close to the terminal assembly 14. During the use of the cylindrical battery, the terminal assembly 14 generates significant heat, while the first insulating layer 30 has a high heat distortion temperature, thus it can withstand the high temperatures at the connection point, preventing the first insulating layer 30 from melting and detaching from the battery cell 20. The second insulating layer 40 is less affected by high temperatures, therefore its heat distortion temperature is relatively low, ensuring good heat dissipation and preventing the accumulation of high heat on the surface of the battery cell 20. Therefore, the technical solution of this embodiment solves the defect in the prior art where the insulating film near the connection area between the tabs and terminals is easily affected by high temperatures during battery use.

[0034] It should be noted that, of the first and second electrodes, one is a positive electrode and the other is a negative electrode.

[0035] Furthermore, in this embodiment, the test method for the high temperature resistance of the first insulating layer 30 and the second insulating layer 40 refers to the national standard GB / T1634-2004 Test Method for Heat Deflection Temperature and Heat Resistance of Plastics.

[0036] As shown in Figure 1, the cylindrical battery has an overall cylindrical structure. The casing 10 of the cylindrical battery includes a circumferential sidewall 11, a first end wall 12, and a second end wall 13. The circumferential sidewall 11 has a cylindrical structure, and the second end wall 13 is connected to the end of the circumferential sidewall 11. The two can be integrally formed, or they can be connected by welding, bonding, or fasteners. The circumferential sidewall 11 and the second end wall 13 form a structure with one open end.

[0037] As shown in Figures 1 and 2, a terminal assembly 14 is provided on the first end wall 12. During assembly, the first and / or second tabs on the battery cell 20 are first connected to the terminal assembly 14, that is, the first end wall 12 is connected to the battery cell 20. Then, the battery cell 20 is placed in the space enclosed by the circumferential side wall 11 and the second end wall 13. At this time, the first end wall 12 covers the opening of the circumferential side wall 11. Finally, the first end wall 12 is welded to the circumferential side wall 11.

[0038] Furthermore, to isolate the battery cell 20 from other structures, an insulating layer is wrapped around the battery cell 20. The insulating layer can be an insulating film, which is attached to the outer peripheral surface of the battery cell 20 in the circumferential direction.

[0039] Furthermore, in order to reduce the impact of heat generation at the pole assembly 14 on the insulation layer, the insulation layer in this embodiment is divided into a first insulation layer 30 and a second insulation layer 40.

[0040] Specifically, as shown in Figures 2 and 3, both the first insulating layer 30 and the second insulating layer 40 circumferentially cover the outside of the battery cell 20. The first insulating layer 30 and the second insulating layer 40 are distributed along the axial direction of the battery cell 20, with the first insulating layer 30 positioned close to the first end wall 12, that is, close to the connection position. The heat distortion temperature of the first insulating layer 30 is greater than that of the second insulating layer 40, and along the axial direction of the battery cell 20, the height of the first insulating layer 30 is less than the height of the second insulating layer 40.

[0041] In this embodiment, the first insulating layer 30 is located close to the terminal assembly 14 and has a high heat distortion temperature. Therefore, when the cylindrical battery is working, the heat generated by the terminal assembly 14 has a relatively small impact on the first insulating layer 30. The first insulating layer 30 can withstand high temperatures, preventing it from melting at high temperatures and detaching from the cell 20.

[0042] Furthermore, while the first insulating layer 30 has a high heat distortion temperature, its heat dissipation capacity is correspondingly reduced. To ensure the overall heat dissipation capacity of the cell 20, the heat distortion temperature of the second insulating layer 40 is set slightly lower than that of the first insulating layer 30. Since the second insulating layer 40 is located far from the terminal assembly 14, the heat generated by the terminal assembly 14 has a smaller impact on the second insulating layer 40, preventing it from melting. Moreover, the lower heat distortion temperature of the second insulating layer 40 provides excellent heat dissipation performance, ensuring the overall heat dissipation capacity of the cell 20.

[0043] Optionally, the heat distortion temperature of the first insulating layer 30 is in the range of 220°C to 280°C.

[0044] Specifically, the heat distortion temperature of the first insulating layer 30 cannot be too low or too high. If the heat distortion temperature of the first insulating layer 30 is too high, it will be detrimental to the heat dissipation of the cylindrical battery. If the heat distortion temperature of the first insulating layer 30 is too low, it will not be able to withstand the high temperature generated at the terminal assembly 14.

[0045] For example, the heat distortion temperature of the first insulating layer 30 can be selected as 220℃, 240℃, 260℃ or 280℃, or any value between two of these values.

[0046] Optionally, the heat distortion temperature of the second insulating layer 40 is in the range of 100°C to 150°C.

[0047] Specifically, the heat distortion temperature of the second insulating layer 40 must not be too low or too high. If the heat distortion temperature of the second insulating layer 40 is too high, it will hinder the heat dissipation of the cylindrical battery. If the heat distortion temperature of the second insulating layer 40 is too low, the second insulating layer 40 will quickly deform under heat, which will easily lead to insulation failure. Even under the normal operating temperature of the cylindrical battery, the second insulating layer 40 may deform or even melt.

[0048] For example, the heat distortion temperature of the second insulating layer 40 can be selected as 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃, or any value between two values.

[0049] Furthermore, it is necessary to ensure that the heat distortion temperature of the first insulating layer 30 is greater than the heat distortion temperature of the second insulating layer 40.

[0050] Furthermore, in the aforementioned configuration of the first and second output stages, the housing 10 serves as the first output stage, and the electrode assembly 14 serves as the second output stage. In this configuration, the first electrode tab is electrically connected to the housing 10, and the second electrode tab is electrically connected to the electrode assembly 14.

[0051] As shown in Figure 3, in the technical solution of this embodiment, the distance d1 between the edge of the first insulating layer 30 facing the first end wall 12 and the first end wall 12 along the axial direction of the cell 20 is in the range of 0 to 4 mm.

[0052] It should be noted that the range of d1 mentioned above does not include 0.

[0053] Specifically, during the use of the cylindrical battery, the first end wall 12 plays a role in bearing the overcurrent, thus generating a large amount of heat and having a high temperature. Therefore, the aforementioned distance d1 should be taken as an appropriate value.

[0054] First, the distance d1 mentioned above cannot be too small. If the distance d1 is too small, it means that the first insulating layer 30 is close to the first end wall 12. Therefore, when the cylindrical battery is working, the heat of the first end wall 12 is more easily transferred to the first insulating layer 30, which makes it easier for the first insulating layer 30 to melt.

[0055] Secondly, the aforementioned distance d1 cannot be too large. If the distance d1 is too small, it means that the first insulating layer 30 is far from the first end wall 12, resulting in a larger exposed area on the outer surface of the cell 20, which weakens the insulation and heat dissipation performance of the first insulating layer 30 to the cell 20. Optionally, the distance d1 can be selected as 0.5mm, 1mm, 2mm, 3mm, or 4mm, or any value between two such values.

[0056] Furthermore, in the technical solution of this embodiment, along the axial direction of the cell 20, the size d2 of the first insulating layer 30 is smaller than the size d3 of the second insulating layer 40.

[0057] Specifically, for the insulating layer, good high-temperature resistance leads to poor heat dissipation. Therefore, if the size d2 of the first insulating layer 30 is too large, it will affect the heat dissipation of the cylindrical battery, especially in the area near the top of the cylindrical battery where heat is relatively high. Heat cannot dissipate outward, which can easily cause thermal runaway of the cylindrical battery. Therefore, the size d2 of the first insulating layer 30 needs to be set relatively small.

[0058] Furthermore, the second insulating layer 40 has poor high-temperature resistance, thus its heat dissipation capacity is strong. Therefore, the size d2 of the second insulating layer 40 needs to be set relatively large to ensure the overall heat dissipation performance of the cylindrical battery.

[0059] Therefore, taking all factors into consideration, in this embodiment, the size d2 of the first insulating layer 30 is smaller than the size d3 of the second insulating layer 40.

[0060] As shown in Figure 3, in the technical solution of this embodiment, the ratio of the size d2 of the first insulating layer 30 to the size d3 of the second insulating layer 40 along the axial direction of the cell 20 is in the range of 0.04 to 0.21.

[0061] As can be seen from Figure 3, in the direction shown in Figure 3, the dimension d2 of the first insulating layer 30 is the height of the first insulating layer 30 in the vertical direction, and the dimension d3 of the second insulating layer 40 is the height of the second insulating layer 40 in the vertical direction.

[0062] First, the ratio of the dimension d2 of the first insulating layer 30 to the dimension d3 of the second insulating layer 40 cannot be too large. If this ratio is too large, it indicates that the height of the first insulating layer 30 is greater than the height of the second insulating layer 40. As mentioned above, although the first insulating layer 30 has strong high-temperature resistance, its heat dissipation capacity is relatively low. Therefore, if the ratio of d2 to d3 is large, it will reduce the overall heat dissipation performance of the cell 20. Furthermore, since the height of the second insulating layer 40 is greater than the height of the first insulating layer 30, the second insulating layer 40 also serves to securely wind the cell 20. If the dimension d3 of the second insulating layer 40 is relatively small, it will lead to a decrease in the secure winding ability of the second insulating layer 40 over the cell 20, resulting in looseness inside the cell 20 and affecting the performance of the cylindrical battery.

[0063] Secondly, the ratio of the dimension d2 of the first insulating layer 30 to the dimension d3 of the second insulating layer 40 cannot be too small. If the ratio is too small, it means that the height of the first insulating layer 30 is smaller than the height of the second insulating layer 40. This will reduce the overall area of ​​the first insulating layer 30, decrease its resistance to high temperatures, and make it easier for heat on the first end wall 12 to continue to be transferred downwards from the first insulating layer 30 to the second insulating layer 40, which may easily cause the second insulating layer 40 to melt.

[0064] Optionally, the ratio of the size d2 of the first insulating layer 30 to the size d3 of the second insulating layer 40 can be selected as 0.04, 0.08, 0.1, 0.15, 0.2 or 0.21, or any value between two values.

[0065] Furthermore, in the technical solution of this embodiment, the size d2 of the first insulating layer 30 along the axial direction of the cell 20 is in the range of 8mm to 18mm.

[0066] Specifically, the height d2 of the first insulating layer 30 should be within an appropriate range. If d2 is too large, the first insulating layer 30, which has poor heat dissipation capacity, will be too large, affecting the overall heat dissipation capacity of the cylindrical battery. If d2 is too small, the second insulating layer 40 will still be attached to the high-temperature area near the first end wall 12, which may easily cause the second insulating layer 40 to melt and lead to insulation failure.

[0067] For example, the dimension d2 of the first insulating layer 30 can be 8mm, 9mm, 10mm, 12mm, 15mm or 18mm, or any value between two such values.

[0068] In the technical solution of this embodiment, when the radius of the cylindrical battery is greater than or equal to 40mm, the ratio of the size d2 of the first insulating layer 30 to the size d3 of the second insulating layer 40 is in the range of 0.06 to 0.18.

[0069] Specifically, for cylindrical batteries, a larger radius results in a larger cell radius, thus leading to higher energy density and greater heat generation during operation. Especially at the top (the location of the first end wall 12), where heat is concentrated, the temperature is higher. Therefore, the size d2 of the first insulating layer 30 should be appropriately increased to cope with the high temperature. That is, the larger the radius of the cylindrical battery, the greater the ratio of the size d2 of the first insulating layer 30 to the size d3 of the second insulating layer 40 should be.

[0070] As shown in Figure 4, in the technical solution of this embodiment, there is an overlapping portion 50 between the first insulating layer 30 and the second insulating layer 40. Along the axial direction of the cell 20, the size d4 of the overlapping portion 50 is in the range of 0 to 4 mm.

[0071] It should be noted that the value range of d4 mentioned above does not include 0.

[0072] Specifically, the overlapping portion 50 can be formed by the first insulating layer 30 covering a portion of the second insulating layer 40 from the outside downward (towards the second end wall 13), or by the second insulating layer 40 covering a portion of the first insulating layer 30 from the outside upward (towards the first end wall 12).

[0073] The reason for setting the overlapping portion 50 in this embodiment is to ensure that the outer periphery of the battery cell 20 is completely wrapped by the first insulating layer 30 and the second insulating layer 40, thereby ensuring the insulation performance of the first insulating layer 30 and the second insulating layer 40 on the battery cell 20 and improving the heat dissipation effect.

[0074] In some embodiments not shown, described in the direction shown in FIG3, the lower edge of the first insulating layer 30 and the upper edge of the second insulating layer 40 may be attached together or have a certain gap.

[0075] As shown in Figure 4, and explained in the direction shown in Figure 4, the dimension d4 of the overlapping part 50 is also the height value of the overlapping part 50.

[0076] First, the dimension d4 of the overlapping portion 50 cannot be too large. If the value of d4 is too large, it means that the overlapping portion 50 of the first insulating layer 30 and the second insulating layer 40 is too large. On the one hand, a thicker overlapping portion 50 will occupy the space of the cylindrical battery, making the capacity of the cylindrical battery smaller. On the other hand, it means that the overlapping portion 50 of the first insulating layer 30 and the second insulating layer 40 is too large, making it easier for the heat of the first insulating layer 30 to be transferred downward to the second insulating layer 40, which may cause the second insulating layer 40 to melt.

[0077] Secondly, the size d4 of the overlapping portion 50 cannot be too small. If the value of d4 is too small, it means that the overlapping portion 50 of the first insulating layer 30 and the second insulating layer 40 is less, and the heat of the first insulating layer cannot be quickly conducted through the second insulating layer, resulting in the first insulating layer being too hot.

[0078] For example, the dimension d4 of the overlapping portion 50 can be selected as 0.05mm, 1mm, 1.5mm, 2mm, 3mm or 4mm, or any value between two values.

[0079] Furthermore, in the technical solution of this embodiment, when the ratio of the area of ​​the first electrode end face to the area of ​​the second electrode end face is in the range of 0.5 to 1, the distance between the edge of the overlapping portion 50 on the side close to the first end wall 12 and the first end wall 12 is in the range of 10mm to 18mm.

[0080] Specifically, since the overlapping portion 50 is formed by stacking the first insulating layer 30 and the second insulating layer 40, the thickness of the overlapping portion 50 is relatively thick, which will hinder heat dissipation. Therefore, in this embodiment, the overlapping portion 50 needs to be at a certain distance from the top region (first end wall 12) where heat is concentrated. That is, as shown in Figure 4, the distance from the upper edge of the overlapping portion 50 to the first end wall 12 is in the range of 10mm to 18mm.

[0081] For example, the distance between the edge of the overlapping portion 50 and the first end wall 12 can be selected as 10mm, 12mm, 14mm, 15mm, 16mm or 18mm, or any value between two such values.

[0082] Furthermore, in the technical solution of this embodiment, the ratio of the thickness of the first insulating layer 30 to the thickness of the second insulating layer 40 is in the range of 0.6 to 1.2.

[0083] Specifically, in this embodiment, the thickness of the first insulating layer 30 is preferably set to be greater than the thickness of the second insulating layer 40, thereby enhancing the high temperature resistance of the first insulating layer 30 and making it less likely for the heat of the first insulating layer 30 to be transferred downward to the second insulating layer 40.

[0084] First, the ratio of the thickness of the first insulating layer 30 to the thickness of the second insulating layer 40 cannot be too large. If the ratio is too large, it means that the thickness of the first insulating layer 30 is relatively thick compared to the thickness of the second insulating layer 40. A thicker first insulating layer 30 will occupy space in the cylindrical battery, resulting in a smaller capacity of the cylindrical battery.

[0085] Secondly, the ratio of the thickness of the first insulating layer 30 to the thickness of the second insulating layer 40 cannot be too small. If the ratio is too small, it means that the thickness of the first insulating layer 30 is similar to that of the second insulating layer 40. A relatively thinner first insulating layer 30 will reduce its high-temperature resistance, making it easier for heat from the first insulating layer 30 to be transferred downwards to the second insulating layer 40, which could easily lead to the second insulating layer 40 melting.

[0086] For example, the ratio of the thickness of the first insulating layer 30 to the thickness of the second insulating layer 40 can be selected as 0.6, 0.8, 1, or 1.2, or any value between two values.

[0087] This application also provides a battery pack, and embodiments of the battery pack according to this application include the cylindrical battery described above.

[0088] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A cylindrical battery, characterized by comprising: The battery includes a housing (10) and a battery cell (20) disposed within the housing (10). The battery cell (20) includes a first tab and a second tab, both located on the same side of the battery cell (20), and having opposite polarities. The housing (10) includes a circumferential sidewall (11) and a first endwall (12) and a second endwall (13) located at both ends of the circumferential sidewall (11). A terminal assembly (14) is disposed on the first endwall (12). A first output terminal is disposed on the housing (10) of the cylindrical battery, and a second output terminal is disposed on the first endwall (12). The outer peripheral surface of the battery cell (20) is provided with a first insulating layer (30) and a second insulating layer (40). The first insulating layer (30) is disposed close to the first end wall (12), and the second insulating layer (40) is located on the side of the first insulating layer (30) away from the first end wall (12). The heat deformation temperature of the first insulating layer (30) is greater than that of the second insulating layer (40).

2. The cylindrical battery according to claim 1, characterized by The heat distortion temperature of the first insulating layer (30) is in the range of 220-280°C; and / or, the heat distortion temperature of the second insulating layer (40) is in the range of 100-150°C.

3. The cylindrical battery according to claim 1, characterized by, The housing (10) serves as the first output electrode, and the pole assembly (14) serves as the second output electrode. The first tab and the second tab are electrically connected to the housing (10) and the pole assembly (14), respectively.

4. The cylindrical battery according to claim 1, characterized by, Along the axial direction of the cell (20), the distance (d1) between the edge of the first insulating layer (30) facing the first end wall (12) and the first end wall (12) is in the range of 0 to 4 mm.

5. The cylindrical battery according to claim 1, characterized by, Along the axial direction of the cell (20), the size (d2) of the first insulating layer (30) is smaller than the size (d3) of the second insulating layer (40).

6. The cylindrical battery according to any one of claims 1 to 5, characterized by, Along the axial direction of the cell (20), the ratio of the size (d2) of the first insulating layer (30) to the size (d3) of the second insulating layer (40) is in the range of 0.04 to 0.

21.

7. The cylindrical battery according to claim 6, characterized by When the radius of the cylindrical battery is greater than or equal to 40 mm, the ratio of the size (d2) of the first insulating layer (30) to the size (d3) of the second insulating layer (40) is in the range of 0.06 to 0.

18.

8. The cylindrical battery according to any one of claims 1 to 5, characterized by, Along the axial direction of the cell (20), the size (d2) of the first insulating layer (30) is in the range of 8 mm to 18 mm.

9. The cylindrical battery according to claim 1, characterized by, There is an overlap (50) between the first insulating layer (30) and the second insulating layer (40), and the size (d4) of the overlap (50) is in the range of 0 to 4 mm along the axial direction of the cell (20).

10. The cylindrical battery as claimed in claim 9, wherein When the ratio of the area of ​​the first electrode end face to the area of ​​the second electrode end face is in the range of 0.5 to 1, the distance from the edge of the overlapping portion (50) on the side closest to the first end wall (12) to the first end wall (12) is in the range of 10 mm to 18 mm.

11. The cylindrical battery according to any one of claims 1 to 5, characterized by, The ratio of the thickness of the first insulating layer (30) to the thickness of the second insulating layer (40) is in the range of 0.6 to 1.

2.

12. The cylindrical battery according to any one of claims 1 to 11, characterized by, The thickness of the first insulating layer (30) is set to be greater than the thickness of the second insulating layer (40), thereby enhancing the high temperature resistance of the first insulating layer (30).

13. The cylindrical battery according to any one of claims 1 to 12, characterized by, The ratio of the thickness of the first insulating layer (30) to the thickness of the second insulating layer (40) is greater than 1 and less than or equal to 1.

2.

14. A battery pack, characterized by Includes the cylindrical battery as described in any one of claims 1 to 13.

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