Cylindrical battery, battery pack, and electric device

Abstract

This utility model relates to a cylindrical battery, a battery pack, and an electrical device. The cylindrical battery includes a casing, a cell, terminals, and a first insulating member. The casing includes a top cover. The cell is disposed within the casing and includes a first tab and a second tab with opposite polarities. The terminals include a terminal body and an inner connection portion. The terminal body extends along its height and passes through the top cover. The inner connection portion is connected to one end of the terminal body located within the casing and extends radially outward from the terminal body. One of the first tab and the second tab is electrically connected to the inner connection portion, and the other is electrically connected to the casing. The first insulating member includes an annular disk portion, which includes a first part located between the top cover and the inner connection portion and in contact with both. The radial dimension of the first part is L1, and the radial dimension of the first insulating member is L2, both in mm, where 0.1 ≤ L1 / L2 ≤ 0.45. The first insulating member not only stably supports the top cover and the inner connection portion to achieve insulation between them but also reduces the probability of heat concentration at the terminals.

Description

Technical Field

[0001] This utility model relates to the field of, and in particular to, a cylindrical battery, a battery pack, and an electrical device. Background Technology

[0002] Cylindrical batteries, as a common lithium-ion battery structure, are widely used in electric vehicles, energy storage systems, and consumer electronics due to their high energy density and mature manufacturing process.

[0003] In the design of cylindrical batteries, the insulation performance and structural stability between the terminals and the casing are crucial to the battery's safety and reliability. Traditional cylindrical batteries typically achieve electrical isolation between the terminals and the casing (especially the top cover) through insulating components to prevent short circuits caused by direct contact between the positive and negative electrodes. However, during battery operation, factors such as vibration and thermal expansion can cause displacement or deformation of the insulating components, thus affecting the insulation effect. Furthermore, an unreasonable design of the contact area and distribution between the terminals and the insulating components can lead to localized heat concentration, affecting the battery's thermal management performance and reducing battery life.

[0004] Therefore, optimizing the structural design of the insulating components to ensure stable insulation between the terminals and the casing, while improving the supporting performance of the insulating components and improving heat distribution, has become an urgent problem to be solved in the field of cylindrical battery technology. Utility Model Content

[0005] In view of this, the present invention provides a cylindrical battery, a battery pack, and an electrical device, which aims to ensure stable insulation between the terminals and the casing while improving the support performance of the insulation components and improving heat distribution.

[0006] In a first aspect, the cylindrical battery provided by this utility model includes a casing, a cell, terminals, and a first insulating member. The casing includes a top cover. The cell is disposed inside the casing and includes a first tab and a second tab with opposite polarities. The terminals include a terminal body and an inner connection portion. The terminal body extends along the height direction and passes through the top cover, and the terminal body is insulated from the casing. The inner connection portion is connected to one end of the terminal body located inside the casing and extends radially outward from the terminal body. The first tab is electrically connected to the inner connection portion, and the second tab is electrically connected to the casing. The first insulating member includes an annular disk portion, which includes a first part located between the top cover and the inner connection portion and in contact with both. The radial dimension of the first part is L1 (mm), and the radial dimension of the first insulating member is L2 (mm), where 0.1 ≤ L1 / L2 ≤ 0.45.

[0007] Secondly, the battery pack provided by this utility model includes the cylindrical battery mentioned above.

[0008] Thirdly, the electrical equipment provided by this utility model includes the cylindrical battery mentioned above, or the battery pack mentioned above.

[0009] The positive effects of the battery pack and the electrical equipment using it proposed in this utility model are as follows:

[0010] A first insulating element is provided between the top cover and the inner connection portion to achieve insulation between the top cover and the inner connection portion, preventing short circuits caused by contact between the positive and negative electrodes. Furthermore, since the first insulating element is in contact with both the top cover and the inner connection portion, it can be stably supported between them, preventing displacement due to adverse vibrations during battery operation. Moreover, the cylindrical battery provided by this invention limits the ratio of the radial dimension of the first portion to the radial dimension of the first insulating element within the aforementioned range, ensuring stable support of the first insulating element between the top cover and the inner connection portion while reducing the probability of heat concentration at the terminals. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below.

[0012] It should be understood that the following figures only show some embodiments of the present invention and should not be regarded as a limitation on the scope.

[0013] It should also be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0014] It should also be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0015] Figure 1 This is a schematic diagram of the structure of a cylindrical battery according to an embodiment of the present invention.

[0016] Figure 2 yes Figure 1 An exploded view of a cylindrical battery.

[0017] Figure 3 yes Figure 1 A cross-sectional view of a cylindrical battery.

[0018] Figure 4 yes Figure 3 A schematic diagram of a portion of a cylindrical battery.

[0019] Figure 5 yes Figure 3 A schematic diagram of a portion of a cylindrical battery.

[0020] Figure 6 yes Figure 4 Enlarged view of section A.

[0021] Figure 7 yes Figure 2A schematic diagram of the structure of the top cover.

[0022] Figure 8 This is an exploded view of a battery pack according to an embodiment of the present invention.

[0023] Figure 9 This is an exploded view of an electrical device according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached drawings: Cylindrical battery - 100; Casing - 10; Top cover - 11; Mounting hole - 12; Mounting groove - 13; Cell - 20; Tab - 21; First tab - 211; Second tab - 212; Cell body - 22; Top surface - 221; Bottom surface - 222; Terminal post - 30; Terminal post body - 31; Inner connection - 32; Outer connection - 33; First insulator - 40; Annular disc - 41; First part - 411; Second part - 412; Cylindrical part - 42; Flange - 43; Support pad - 50; Second insulator - 60; Seal - 70; Battery pack - 200; Electrical device - 1000. Detailed Implementation

[0025] The embodiments of the present invention will now be described by way of example with reference to the accompanying drawings. It should be understood that there are many ways to implement the present invention, and it should not be construed as being limited to the embodiments described herein. The embodiments described herein are only for a more thorough and clear understanding of the present invention.

[0026] <Example cylindrical battery>

[0027] Figure 1 and Figure 2 The structure of a cylindrical battery 100 is shown below. The cylindrical battery 100 includes a casing 10, a cell 20, and terminals 30. Figures 3 to 7 This section introduces the components of the cylindrical battery 100.

[0028] The housing 10 includes a top cover 11, which has a mounting hole 12 extending through the height direction.

[0029] The battery cell 20 is disposed within the housing 10 and includes a first tab 211, a second tab 212, and a battery cell body 22. The battery cell body 22 has a top surface 221 and a bottom surface 222 opposite to each other along its height direction, with the top surface 221 being closer to the top cover 11 than the bottom surface 222. The first tab 211 and the second tab 212 have opposite polarities and are electrically connected to the battery cell body 22. As an example, the battery cell body 22 is formed by winding a positive electrode plate, a negative electrode plate, and a separator. The first tab 211 is the positive tab 21, and the second tab 212 is the negative tab 21. The first tab 211 is connected to the positive electrode plate and extends from the top surface 221 of the battery cell body 22, while the second tab 212 is connected to the negative electrode plate and extends from the bottom surface 222 of the battery cell body 22. The second tab 212 is electrically connected to the housing 10.

[0030] The electrode post 30 includes an electrode post body 31, an inner connection portion 32, and an outer connection portion 33. The electrode post body 31 extends along the height direction and passes through the mounting hole 12. The electrode post 30 is insulated from the housing 10. The inner connection portion 32 is connected to the end of the electrode post body 31 located inside the housing 10 and extends radially outward from the electrode post body 31. The first electrode tab 211 is electrically connected to the inner connection portion 32. The outer connection portion 33 is connected to the end of the electrode post body 31 located outside the housing 10 and extends radially outward from the electrode post body 31. The outer connection portion 33 is used to connect to an external circuit.

[0031] It should be noted that, since the radial dimensions of both the inner portion 32 and the outer portion 33 are larger than those of the pole body 31, and the inner diameter of the mounting hole 12 is smaller than the outer diameters of the inner portion 32 and the outer portion 33, if the pole 30 is integrally formed before installation, the inner portion 32 will not be able to pass through the mounting hole 12. Therefore, during the installation of the pole 30 onto the top cover 11, the pole 30 needs to pass entirely through the mounting hole 12, and then the inner portion 32 and the outer portion 33 are formed through a flanging or riveting process, extending radially outward from the pole body 31.

[0032] It is understood that in this invention, directional descriptions such as "top" and "bottom" are relative rather than absolute. These directional descriptions apply when the elements in this invention are in the placement posture and position shown in the figures. It should be noted that in the figures of this invention, arrows X+ and X- are used to indicate opposite sides in the height direction. For example, when describing the top and bottom of the cylindrical battery 100, the side indicated by arrow X+ is the top, and the side indicated by arrow X- is the bottom.

[0033] In the current embodiment, the terminal 30 serves as the positive electrode of the cylindrical battery 100, and the casing 10 serves as the negative electrode. If the terminal 30 comes into contact with the casing 10, a short circuit will occur. To ensure electrical safety between the terminal 30 and the casing 10, refer to... Figure 4 and Figure 5The cylindrical battery 100 provided by this utility model also includes a first insulating member 40. The first insulating member 40 includes an annular disk portion 41, which includes a first portion 411 located between the top cover 11 and the inner connection portion 32 and in contact with both. The radial dimension of the first portion 411 is L1 in mm, and the radial dimension of the first insulating member 40 is L2 in mm, where 0.1 ≤ L1 / L2 ≤ 0.45. For example, L1 / L2 can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or 0.45. Preferably, L1 / L2 can satisfy: 0.2 ≤ H2 / H3 ≤ 0.35.

[0034] A first insulating member 40 is provided between the top cover 11 and the inner connection portion 32 to achieve insulation between the top cover 11 and the inner connection portion 32, preventing short circuits caused by contact between the positive and negative electrodes. In addition, the first insulating member 40 is in contact with both the top cover 11 and the inner connection portion 32, so the first insulating member 40 can be stably supported between the top cover 11 and the inner connection portion 32, preventing it from being displaced due to adverse vibrations during battery operation.

[0035] Furthermore, the cylindrical battery 100 provided by this utility model limits the ratio of the radial dimension of the first portion 411 to the radial dimension of the first insulating member 40. If the ratio of the radial dimension of the first portion 411 to the radial dimension of the first insulating member 40 is too small, i.e., less than 0.1, the contact area between the first insulating member 40 and both the top cover 11 and the inner connection portion 32 is small, which reduces the stability of the first insulating member 40 supported between the top cover 11 and the inner connection portion 32. If the ratio of the radial dimension of the first portion 411 to the radial dimension of the first insulating member 40 is too large, i.e., greater than 0.45, the contact area between the first insulating member 40 and the inner connection portion 32 is large, which makes it difficult for the heat generated by the inner connection portion 32 during operation to dissipate, thereby affecting the heat dissipation of the terminal post 30. According to the cylindrical battery 100 provided by this utility model, the ratio of the radial dimension of the first part 411 to the radial dimension of the first insulating member 40 is limited to the above-mentioned numerical range, which can ensure that the first insulating member 40 is stably supported between the top cover 11 and the inner part 32, and reduce the probability of heat concentration in the terminal post 30.

[0036] refer to Figure 4 and Figure 5 The first insulating member 40 also includes a cylindrical portion 42, which extends from the outer edge of the annular disk portion 41 toward the side opposite to the top cover 11. The distance from the inner circumferential surface of the cylindrical portion 42 to the outer circumferential surface of the inner connecting portion 32 is L3, in mm, and 0.52≤L3 / L2≤0.87. For example, L3 / L2 can be 0.52, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.87. Preferably, L3 / L2 can satisfy: 0.6≤H2 / H3≤0.8.

[0037] If the ratio of the distance from the inner circumferential surface of the cylindrical portion 42 to the outer circumferential surface of the inner connection portion 32 to the radial dimension of the first insulating member 40 is small, i.e., less than 0.52, then the radial dimension of the inner connection portion 32 is large. This not only increases manufacturing costs but also increases the difficulty of deforming the inner connection portion 32. If the ratio of the distance from the inner circumferential surface of the cylindrical portion 42 to the outer circumferential surface of the inner connection portion 32 to the radial dimension of the first insulating member 40 is large, i.e., greater than 0.87, then the radial dimension of the inner connection portion 32 is small. This will result in insufficient electrical connection area between it and the tab 21, leading to increased contact resistance. When current flows, the connection between the tab 21 and the inner connection portion 32 will heat up due to resistance, potentially causing thermal runaway. According to the cylindrical battery 100 provided by this utility model, the ratio of the distance from the inner circumferential surface of the cylindrical portion 42 to the outer circumferential surface of the inner connecting portion 32 to the radial dimension of the first insulating member 40 is limited to the above-mentioned numerical range. Under the premise of ensuring that the pole post 30 and the pole tab 21 have sufficient connection area, the manufacturing cost and processing difficulty can also be reduced.

[0038] Continue to refer to Figure 4 and Figure 5 The cylindrical portion 42 extends beyond the top surface 221 in the direction away from the top cover 11. According to the implementation provided by this invention, at least a portion of the cylindrical portion 42 is located between the cell body 22 and the housing 10, achieving insulation between the cell body 22 and the housing 10 and preventing short circuits caused by contact between them. Furthermore, since the first tab 211 extends from the top surface 221, the cylindrical portion 42 also extends beyond the first tab 211 in the direction away from the top cover 11. In this way, even if the radial distance between the first tab 211 and the housing 10 is small, the first tab 211 and the housing 10 can still be separated by at least a portion of the cylindrical portion 42, thereby achieving insulation between the first tab 211 and the housing 10, preventing short circuits caused by contact between them, and thus ensuring the electrical safety of the cylindrical battery 100.

[0039] As one possible implementation, the elastic modulus of the first insulating element 40 is E, in GPa, and 3 ≤ E ≤ 10. For example, E can be 3, 4, 5, 6, 7, 8, 9 or 10, and preferably, E can satisfy: 5 ≤ E ≤ 8.

[0040] During the charging and discharging process of the cylindrical battery 100, the cell body 22 may expand outward. After the cell body 22 expands outward, it will come into contact with the cylindrical portion 42. The cylindrical portion 42 has a small elastic modulus, and its structure can effectively absorb the expansion deformation of the cell body 22 through elastic deformation. Therefore, it significantly reduces the stress transmitted to the housing 10 and avoids obvious bulging deformation of the housing 10.

[0041] refer to Figure 4 and Figure 5The outer peripheral surface of the cylindrical portion 42 contacts the inner surface of the housing 10, and the inner peripheral surface of the cylindrical portion 42 gradually expands outward in the direction away from the annular disk portion 41. In this way, as at least a portion of the battery cell body 22 extends into the space defined by the cylindrical portion 42, the inner peripheral surface of the cylindrical portion 42 can guide the battery cell body 22 to be aligned. Even if there is an initial positional deviation, the battery cell body 22 can be installed into the target position through contact and sliding with the inner peripheral surface of the cylindrical portion 42. Therefore, this implementation method can reduce the installation difficulty and improve the installation efficiency.

[0042] refer to Figure 6 The annular disk portion 41 also includes a second portion 412 extending radially inward from the first portion 411. The second portion 412 contacts the top cover 11, and the bottom surface of the second portion 412 facing away from the top cover 11 is spaced apart from the inner connection portion 32. Since the second portion 412 is located between the top cover 11 and the inner connection portion 32, insulation between the top cover 11 and the inner connection portion 32 can be achieved. At the same time, the bottom surface of the second portion 412 is spaced apart from the inner connection portion 32, which can reduce the contact area between the first insulating member 40 and the inner connection portion 32. The heat generated by the pole post 30 during operation can be dissipated into the space between the second portion 412 and the inner connection portion 32, thus reducing the probability of heat concentration in the pole post 30.

[0043] As mentioned earlier, during the forming process of the inner connection portion 32, a flanging or riveting process can be used to extend it radially outward from the pole body 31. When the inner connection portion 32 is in the target position, it contacts the first insulating member 40. Therefore, during the forming process of the inner connection portion 32, the first insulating member 40 will be compressed by the inner connection portion 32. If the contact area between the first insulating member 40 and the inner connection portion 32 is small, it can easily cause structural damage to the first part 411.

[0044] To solve the above problems, refer to Figure 6 The cylindrical battery 100 provided by this utility model also includes a support pad 50, which surrounds the electrode body 31 and is located between the second part 412 and the inner connection part 32. Both the second part 412 and the inner connection part 32 are in contact with the support pad 50. During the forming process of the inner connection part 32, the support pad 50 and the first insulating member 40 jointly bear the pressure from the inner connection part 32, thus reducing the risk of damage to the first insulating member 40.

[0045] Furthermore, the thermal conductivity of the support pad 50 is greater than that of the first insulating element 40. This allows the heat generated by the electrode post 30 during operation to be dissipated through the support pad 50, thus reducing the probability of heat concentration in the electrode post 30.

[0046] It is understood that the present invention does not impose any special restrictions on the materials of the first insulating element 40 and the support pad 50. For example, the material of the first insulating element 40 can be one of polyphenylene sulfide (PPS), liquid crystal polymer (LCP), and polypropylene (PP), and the material of the support pad 50 can be one of stainless steel, aluminum alloy, and copper.

[0047] refer to Figure 6 The inner edge of the annular disk portion 41 is provided with a flange portion 43 protruding toward the top cover 11, and the flange portion 43 extends into the mounting hole 12. In this way, the flange portion 43 is located between the inner peripheral surface of the mounting hole 12 and the outer peripheral surface of the pole body 31, thereby achieving insulation between the top cover 11 and the pole 30.

[0048] refer to Figure 6 and Figure 7 The cylindrical battery 100 also includes a second insulating member 60 and a sealing member 70. A mounting groove 13 is provided on the side of the top cover 11 facing away from the cell 20. The second insulating member 60 is located in the mounting groove 13 and spaced between the external connection portion 33 and the top cover 11. The sealing member 70 is located in the mounting groove 13 and surrounds the terminal body 31. By providing the mounting groove 13 on the top cover 11, and with both the second insulating member 60 and the sealing member 70 located within the mounting groove 13, the overall structure of the cylindrical battery 100 can be made more compact. Simultaneously, the second insulating member 60, located in the mounting groove 13 and spaced apart from the external connection portion 33 and the top cover 11, can achieve insulation between the terminal 30 and the top cover 11, preventing short circuits caused by contact between the two. The sealing member 70, surrounding the terminal body 31 and located in the mounting groove 13, helps enhance the sealing performance between the terminal 30 and the casing 10, preventing electrolyte leakage from the cell 20 or external impurities from entering the battery, thereby improving the battery's reliability and lifespan.

[0049] <Example Battery Pack>

[0050] This utility model embodiment also provides a battery pack 200, see reference. Figure 8 The battery pack 200 includes multiple cylindrical batteries 100, which can be connected in series and / or in parallel.

[0051] <Example Electrical Equipment>

[0052] This utility model embodiment also provides an electrical device 1000, which may include the battery pack 200 or the cylindrical battery 100 described above.

[0053] By way of example only, electrical equipment 1000 can be, but is not limited to, vehicles, ships, aircraft, household appliances, and industrial equipment. For example, vehicles can be passenger cars, trucks, engineering vehicles, etc.

[0054] In addition, the electrical equipment 1000 can also be used for the storage, conversion and release of recyclable electrical energy.

[0055] In a non-restrictive example, refer to Figure 9 The electrical equipment 1000 can be used for the electric vehicle 1000, and the battery pack 200 can be used as a power source to provide power to the electric vehicle 1000.

[0056] It should be understood that the term "comprising" and its variations used in this utility model are open-ended, meaning "including but not limited to". The term "according to" means "at least in part according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least another embodiment".

[0057] It should be understood that although terms such as "first" or "second" may be used in this invention to describe various elements (such as the first part and the second part), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0058] The scope of protection of this utility model is not limited to the above embodiments. Any variations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A cylindrical battery (100), characterized in that, include: The housing (10) includes a top cover (11); The battery cell (20) is disposed within the housing (10) and includes a first tab (211) and a second tab (212) with opposite polarities; A pole (30) includes a pole body (31) and an inner connection (32), the pole body (31) extending along the height direction and passing through the top cover (11), and the pole (30) being insulated from the housing (10), the inner connection (32) being connected to one end of the pole body (31) located inside the housing (10) and extending radially outward from the pole body (31), a first tab (211) being electrically connected to the inner connection (32), and a second tab (212) being electrically connected to the housing (10); and The first insulating element (40) includes an annular disk portion (41), the annular disk portion (41) including a first part (411) located between and in contact with the top cover (11) and the inner part (32), the first part (411) having a radial dimension of L1 in mm, and the first insulating element (40) having a radial dimension of L2 in mm, 0.1≤L1 / L2≤0.

45.

2. The cylindrical battery (100) according to claim 1, characterized in that, The first insulating member (40) further includes a cylindrical portion (42) that extends from the outer edge of the annular disk portion (41) toward the side away from the top cover (11). The distance from the inner circumferential surface of the cylindrical portion (42) to the outer circumferential surface of the inner connection portion (32) is L3, in mm, and 0.52≤L3 / L2≤0.

87.

3. The cylindrical battery (100) according to claim 1, characterized in that, The first insulating member (40) further includes a cylindrical portion (42) that extends from the outer edge of the annular disk portion (41) toward the side away from the top cover (11). The battery cell (20) includes a battery cell body (22) that has opposing top surface (221) and bottom surface (222) along the height direction. The top surface (221) is closer to the top cover (11) than the bottom surface (222). The cylindrical portion (42) extends beyond the top surface (221) in a direction away from the top cover (11).

4. The cylindrical battery (100) according to claim 3, characterized in that, The elastic modulus of the first insulating element (40) is E, with units of GPa, and 3≤E≤10.

5. The cylindrical battery (100) according to claim 1, characterized in that, The annular disk portion (41) further includes a second portion (412) extending radially inward from the first portion (411), the second portion (412) contacting the top cover (11), and the bottom surface of the second portion (412) facing away from the top cover (11) being spaced apart from the inner portion (32).

6. The cylindrical battery (100) according to claim 5, characterized in that, It also includes a support pad (50) surrounding the pole body (31) and located between the second part (412) and the inner part (32), both of which are in contact with the support pad (50), wherein the thermal conductivity of the support pad (50) is greater than that of the first insulating member (40).

7. The cylindrical battery (100) according to claim 6, characterized in that: The first insulating element (40) is made of one of polyphenylene sulfide, liquid crystal polymer, and polypropylene; and / or The support pad (50) is made of one of stainless steel, aluminum alloy and copper.

8. The cylindrical battery (100) according to claim 1, characterized in that, The first insulating member (40) further includes a cylindrical portion (42) that extends from the outer edge of the annular disk portion (41) toward the side away from the top cover (11). The outer peripheral surface of the cylindrical portion (42) contacts the inner surface of the housing (10), and the inner peripheral surface of the cylindrical portion (42) gradually expands outward in the direction away from the annular disk portion (41).

9. The cylindrical battery (100) according to claim 1, characterized in that, The top cover (11) is provided with a mounting hole (12) that extends through the height direction. The pole body (31) passes through the mounting hole (12). The inner edge of the annular disk (41) is provided with a flange (43) that protrudes toward the top cover (11). The flange (43) extends into the mounting hole (12).

10. The cylindrical battery (100) according to any one of claims 1 to 9, characterized in that, It also includes a second insulating member (60) and a sealing member (70). The pole post (30) also includes an external part (33), which is connected to one end of the pole post body (31) located outside the housing (10) and extends radially outward from the pole post body (31). The top cover (11) has a mounting groove (13) on the side facing away from the battery cell (20). The second insulating member (60) is located in the mounting groove (13) and spaced between the external part (33) and the top cover (11). The sealing member (70) is located in the mounting groove (13) surrounding the pole post body (31).

11. A battery pack (200), characterized in that, The cylindrical battery (100) includes any one of claims 1 to 10.

12. An electrical appliance (1000), characterized in that, It includes the cylindrical battery (100) according to any one of claims 1 to 11, or the battery pack (200) according to claim 11.

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