Lithium ion battery

Abstract

The application provides a lithium ion battery. The lithium ion battery comprises a cylindrical shell, a top cover, a bottom cover and an electrode assembly. The cylindrical shell comprises a first flat plate, a first arc-shaped plate, a second flat plate and a second arc-shaped plate connected head to tail to form an accommodating cavity, and the first arc-shaped plate and / or the second arc-shaped plate protrudes towards a side away from the accommodating cavity. The top cover is arranged on a first opening end of the cylindrical shell. The bottom cover is arranged on a second opening end of the cylindrical shell. The electrode assembly is arranged in the accommodating cavity. The first flat plate and the second flat plate are arranged in parallel to each other, and the first flat plate and the second flat plate have a distance H1. The maximum distance D1 between the first arc-shaped plate and the second arc-shaped plate satisfies the following relationships: H1 is greater than or equal to 2.0 mm; D1 is greater than 2.0 mm; and / or D1 is greater than H1. The application effectively solves the problem of low internal space utilization of the lithium ion battery in the related art.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a lithium-ion battery. Background Technology

[0002] Currently, lithium-ion battery design mainly focuses on the development of soft-pack cylindrical, prismatic, and hard-shell cylindrical and prismatic lithium-ion batteries. However, these battery forms are gradually showing some limitations in the application of wearable products.

[0003] In the existing technology, although soft-pack cylindrical and square lithium-ion batteries are widely used in wearable devices due to their thinness and flexibility, the side sealing and folding process of both results in low utilization of internal space, which affects the improvement of battery energy density. Since the capacity of active materials inside the battery is limited by the space occupied by the folding, the optimal configuration cannot be achieved. Summary of the Invention

[0004] The main objective of this application is to provide a lithium-ion battery to solve the problem of low internal space utilization in lithium-ion batteries in related technologies.

[0005] To achieve the above objectives, this application provides a lithium-ion battery, comprising: a cylindrical casing including a first flat plate, a first arc-shaped plate, a second flat plate, and a second arc-shaped plate connected end to end to form a receiving cavity, wherein the first arc-shaped plate and / or the second arc-shaped plate protrudes toward a side opposite to the receiving cavity; a top cover disposed on a first open end of the cylindrical casing; a bottom cover disposed on a second open end of the cylindrical casing; and a cell assembly disposed within the receiving cavity; wherein the first flat plate and the second flat plate are arranged parallel to each other, and there is a distance H1 between the first flat plate and the second flat plate, and the maximum distance D1 between the first arc-shaped plate and the second arc-shaped plate satisfies the following relationships: H1≥2.0mm; and / or, D1>2.0mm; and / or, D1>H1.

[0006] Furthermore, the first arc-shaped plate and the second arc-shaped plate are symmetrically arranged about the center plane S1 of the cylindrical shell.

[0007] Furthermore, the centers of the first and second arc-shaped plates are set concentrically.

[0008] Furthermore, the connection between the first flat plate and the first arc-shaped plate is transitioned through a first arc plate; and / or, the connection between the first flat plate and the second arc-shaped plate is transitioned through a second arc plate; and / or, the connection between the second flat plate and the first arc-shaped plate is transitioned through a third arc plate; and / or, the connection between the second flat plate and the second arc-shaped plate is transitioned through a fourth arc plate.

[0009] Furthermore, the battery cell assembly includes a positive electrode tab, and the top cover includes: a cover plate having a through hole; a terminal post passing through the through hole, with a first end of the terminal post connected to the positive electrode tab; a pressure ring fitted over the second end of the terminal post to press the terminal post tightly against the cover plate; and a sealing structure, wherein a portion of the sealing structure is located between the hole wall of the through hole and the terminal post, a portion of the sealing structure is located between the first end of the terminal post and the cover plate, and another portion of the sealing structure is located between the pressure ring and the cover plate.

[0010] Furthermore, along the direction from the top cover to the cylindrical shell, the through hole includes a first hole segment, a second hole segment, and a third hole segment connected in sequence, wherein the inner diameter of the first hole segment is larger than the inner diameter of the second hole segment, and the inner diameter of the second hole segment is larger than the inner diameter of the third hole segment; wherein, along the direction from the top cover to the cylindrical shell, the inner diameter of the first hole segment gradually decreases; and / or, at least a portion of the inner diameter of the second hole segment gradually decreases.

[0011] Furthermore, along the direction from the top cover to the cylindrical shell, the pressure ring includes a first ring body, a second ring body, and a third ring body connected in sequence. The outer diameter of the first ring body is larger than the outer diameter of the second ring body, and the outer diameter of the second ring body is larger than the outer diameter of the third ring body. The outer circumferential surface of the second ring body is connected to the outer circumferential surface of the third ring body through an annular plane. The third ring body, at least a portion of the second ring body, and the annular plane are pressed against the sealing structure. Among these, along the direction from the top cover to the cylindrical shell, the outer diameter of the second ring body gradually decreases; and / or, the outer diameter of the third ring body gradually decreases.

[0012] Furthermore, the electrode post includes: a column body, which is inserted into the through hole, the column body including a first column body segment and a second column body segment connected to each other, the outer diameter of the first column body segment being larger than the outer diameter of the second column body segment; a connecting plate, which is connected to the end of the first column body segment away from the second column body segment, and the connecting plate is connected to the positive electrode tab; wherein, the end of the second column body segment away from the first column body segment has a deformation hole, and the diameter of the deformation hole gradually decreases along the direction from the second column body segment to the first column body segment, so as to generate a deformation compression ring and sealing structure under pressure.

[0013] Furthermore, the battery cell assembly includes a negative electrode tab. Along the direction from the bottom cover to the cylindrical housing, the bottom cover includes a first plate, a second plate, and a third plate connected in sequence. The connection between the first plate and the second plate forms a first stepped surface, and the connection between the second plate and the third plate forms a second stepped surface. The first plate is located outside the cylindrical housing, the second plate extends into the cylindrical housing and its outer peripheral surface contacts the cavity wall of the receiving cavity, and the negative electrode tab is connected to the third plate.

[0014] Furthermore, the battery cell assembly also includes multiple electrode groups, each electrode group including a positive electrode, a separator and a negative electrode connected in sequence; wherein, the multiple electrode groups are stacked or wound in sequence.

[0015] Applying the technical solution of this application, a lithium-ion battery includes a cylindrical shell, a top cover, a bottom cover, and a cell assembly. The cylindrical shell includes a first flat plate, a first arc-shaped plate, a second flat plate, and a second arc-shaped plate connected end-to-end to form a receiving cavity. The first arc-shaped plate and / or the second arc-shaped plate protrude towards the side opposite to the receiving cavity. The top cover is disposed on the first open end of the cylindrical shell. The bottom cover is disposed on the second open end of the cylindrical shell. The cell assembly is disposed within the receiving cavity. Thus, by arranging the first and second flat plates parallel to each other and the first and / or second arc-shaped plates protruding towards the side opposite to the receiving cavity, the cylindrical shell forms an elliptical-like structure. This provides a larger receiving cavity space without increasing the overall volume of the battery, thereby increasing the loading of active materials and solving the problem of low internal space utilization in lithium-ion batteries in related technologies, thereby effectively improving the energy density of lithium-ion batteries. Meanwhile, by limiting the distance H1 between the first plate and the second plate, and the maximum distance D1 between the first arc plate and the second arc plate to satisfy the following relationships: H1≥2.0mm; and / or, D1>2.0mm; and / or, D1>H1, the cylindrical shell can ensure a certain thickness to ensure structural strength and safety, while also making the lithium-ion battery thinner and more suitable for the lightweight requirements of wearable devices.

[0016] Compared to traditional square or cylindrical batteries, the cylindrical casing of the lithium-ion battery in this application is better able to adapt to irregular spaces inside wearable devices, thus improving space utilization. Attached Figure Description

[0017] 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:

[0018] Figure 1 A cross-sectional view of a first embodiment of a lithium-ion battery according to this application is shown;

[0019] Figure 2 It shows Figure 1 A cross-sectional view of the cylindrical casing of a lithium-ion battery.

[0020] Figure 3 It shows Figure 1 A cross-sectional view of the top cover of the lithium-ion battery in the image;

[0021] Figure 4 It shows Figure 3 A sectional view of the top cover plate of the structure;

[0022] Figure 5 It shows Figure 3 A cross-sectional view of the pole of the top cover;

[0023] Figure 6 It shows Figure 3 A cross-sectional view of the pressure ring of the top cover;

[0024] Figure 7 It shows Figure 1 A cross-sectional view of the bottom cover of the lithium-ion battery; and

[0025] Figure 8 A cross-sectional view of the cylindrical casing of a lithium-ion battery according to Embodiment 2 of this application is shown.

[0026] The above figures include the following reference numerals:

[0027] 10. Cylindrical shell; 11. First flat plate; 12. First arc-shaped plate; 13. Second flat plate; 14. Second arc-shaped plate;

[0028] 20. Top cover; 21. Cover plate; 211. Through hole; 2111. First hole section; 2112. Second hole section; 2113. Third hole section; 22. End post; 221. Post body; 2211. First post body section; 2212. Second post body section; 2213. Deformation hole; 222. Connecting plate; 23. Pressure ring; 231. First ring body; 232. Second ring body; 233. Third ring body; 234. Annular plane; 24. Sealing structure;

[0029] 30. Bottom cover; 31. First plate; 32. Second plate; 33. Third plate; 34. First step surface; 35. Second step surface;

[0030] 40. Battery cell assembly; 41. Positive electrode tab; 42. Negative electrode tab; 43. Electrode assembly; 431. Positive electrode sheet; 432. Separator; 433. Negative electrode sheet. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0034] To address the issue of low internal space utilization in lithium-ion batteries in related technologies, this application provides a lithium-ion battery.

[0035] Example 1

[0036] like Figures 1 to 7 As shown, the lithium-ion battery includes a cylindrical casing 10, a top cover 20, a bottom cover 30, and a cell assembly 40. The cylindrical casing 10 includes a first flat plate 11, a first arc-shaped plate 12, a second flat plate 13, and a second arc-shaped plate 14 connected end-to-end to form a receiving cavity. The first arc-shaped plate 12 and the second arc-shaped plate 14 protrude towards the side opposite to the receiving cavity. The top cover 20 is disposed on the first open end of the cylindrical casing 10, and the bottom cover 30 is disposed on the second open end of the cylindrical casing 10. The cell assembly 40 is disposed within the receiving cavity. The first flat plate 11 and the second flat plate 13 are arranged parallel to each other, with a distance H1 between them. The maximum distance D1 between the first arc-shaped plate 12 and the second arc-shaped plate 14 satisfies the following relationship: H1 ≥ 2.0 mm, D1 > 2.0 mm, D1 > H1.

[0037] By applying the technical solution of this embodiment, the first flat plate 11 and the second flat plate 13 are arranged parallel to each other, and the first arc-shaped plate 12 and the second arc-shaped plate 14 protrude towards the side away from the receiving cavity, so that the cylindrical shell 10 forms an elliptical structure. This provides a larger receiving cavity space without increasing the overall volume of the battery, thereby increasing the loading of active materials and solving the problem of low internal space utilization in lithium-ion batteries in related technologies, thus effectively improving the energy density of lithium-ion batteries. At the same time, by limiting the distance H1 between the first flat plate 11 and the second flat plate 13 and the maximum distance D1 between the first arc-shaped plate 12 and the second arc-shaped plate 14 to satisfy the following relationships: H1≥2.0mm, D1>2.0mm, D1>H1, the cylindrical shell 10 can ensure a certain thickness to ensure structural strength and safety, while also making the lithium-ion battery thinner and more suitable for the lightweight requirements of wearable devices.

[0038] Compared to traditional square or cylindrical batteries, the cylindrical casing of the lithium-ion battery in this embodiment is better able to adapt to irregular spaces inside wearable devices, thus improving space utilization.

[0039] In other embodiments not shown in the accompanying drawings, only the first arc-shaped plate protrudes toward the side opposite to the receiving cavity, so that the shape of the cylindrical shell can be selected more flexibly to meet different usage requirements and working conditions, and also improve the processing flexibility of the workers.

[0040] In other embodiments not shown in the accompanying drawings, the first plate and the second plate are separated by a distance H1 and satisfy the relationship: H1 ≥ 2.0 mm.

[0041] In other embodiments not shown in the accompanying drawings, the maximum distance D1 between the first arc-shaped plate and the second arc-shaped plate satisfies the relationship: D1 > 2.0 mm.

[0042] In other embodiments not shown in the accompanying drawings, there is a distance H1 between the first plate and the second plate, and the maximum distance D1 between the first arc plate and the second arc plate satisfies the relationship: D1 > H1.

[0043] In other embodiments not shown in the accompanying drawings, the first plate and the second plate are separated by a distance H1 and satisfy the relationship: H1 ≥ 2.0 mm, or the maximum distance D1 between the first arc plate and the second arc plate satisfies the relationship: D1 > 2.0 mm.

[0044] In other embodiments not shown in the accompanying drawings, the first plate and the second plate are separated by a distance H1 and satisfy the relationship: H1 ≥ 2.0 mm, and the maximum distance D1 between the first arc plate and the second arc plate satisfies the relationship: D1 > H1.

[0045] Optionally, the first arc-shaped plate 12 and the second arc-shaped plate 14 are symmetrically arranged about the center plane S1 of the cylindrical shell 10; or, the centers of the first arc-shaped plate 12 and the second arc-shaped plate 14 are concentric. In this way, the above arrangement makes the shape selection of the first arc-shaped plate 12 and the second arc-shaped plate 14 more flexible to meet different usage requirements and working conditions, and also improves the processing flexibility of the workers.

[0046] In this embodiment, the first arc plate 12 and the second arc plate 14 are symmetrically arranged about the center plane S1 of the cylindrical shell 10, thereby ensuring the balanced spatial distribution of the cylindrical shell 10, thus providing better mechanical stability, and helping to reduce structural deformation or damage to the lithium-ion battery caused by external impact or pressure during use.

[0047] In other embodiments not shown in the accompanying drawings, the centers of the first and second arc-shaped plates are concentric to ensure the radial structural consistency of the cylindrical shell, which helps to evenly distribute internal pressure, reduce stress concentration, and further improve the stability and durability of the battery structure.

[0048] Optionally, the connection between the first flat plate 11 and the first arc-shaped plate 12 is transitioned by a first arc plate; and / or, the connection between the first flat plate 11 and the second arc-shaped plate 14 is transitioned by a second arc plate; and / or, the connection between the second flat plate 13 and the first arc-shaped plate 12 is transitioned by a third arc plate; and / or, the connection between the second flat plate 13 and the second arc-shaped plate 14 is transitioned by a fourth arc plate. In this way, the above arrangement ensures a smooth transition at the connection between the flat plate and the arc-shaped plate, not only avoiding sharp edges or corners that could cut or scratch the user and improving the user experience, but also preventing stress concentration at the connection that could affect the structural strength of the cylindrical shell 10.

[0049] In this embodiment, the connection between the first flat plate 11 and the first arc-shaped plate 12 is transitioned by a first arc plate; the connection between the first flat plate 11 and the second arc-shaped plate 14 is transitioned by a second arc plate; the connection between the second flat plate 13 and the first arc-shaped plate 12 is transitioned by a third arc plate; and the connection between the second flat plate 13 and the second arc-shaped plate 14 is transitioned by a fourth arc plate. By using arc plates for transitional connections at the connections of the first flat plate 11 and the first arc-shaped plate 12, the first flat plate 11 and the second arc-shaped plate 14, the second flat plate 13 and the first arc-shaped plate 12, and the second flat plate 13 and the second arc-shaped plate 14, stress can be effectively dispersed, avoiding stress concentration points at the edges of the cylindrical shell 10, thereby improving the structural strength and compressive strength of the cylindrical shell 10. Simultaneously, arc transition connections distribute loads more evenly than right-angle connections, reducing localized stress in the material and extending the lifespan of the lithium-ion battery.

[0050] Specifically, the transition design of the first, second, third, and fourth arc plates can make the internal space of the cylindrical shell 10 smoother and more continuous, reduce the ineffective area of ​​the internal space, thereby increasing the loading of active materials inside the lithium-ion battery and thus improving the energy density of the lithium-ion battery.

[0051] like Figure 3 As shown, the battery cell assembly 40 includes a positive electrode tab 41, and the top cover 20 includes a cover plate 21, a terminal post 22, a pressure ring 23, and a sealing structure 24. The cover plate 21 has a through hole 211, through which the terminal post 22 passes, with its first end connected to the positive electrode tab 41. The pressure ring 23 is fitted over the second end of the terminal post 22 to press it firmly against the cover plate 21. A portion of the sealing structure 24 is located between the wall of the through hole 211 and the terminal post 22, another portion is located between the first end of the terminal post 22 and the cover plate 21, and a third portion is located between the pressure ring 23 and the cover plate 21. Thus, by inserting the terminal post 22 through the through hole 211 of the cover plate 21 and then pressing it with the pressure ring 23, along with the sealing structure 24, the assembly process of the top cover 20 is simplified, the assembly difficulty is reduced, and production efficiency and product consistency are improved. Meanwhile, the tight connection and optimized sealing structure of the components in the top cover 20 help improve the internal thermal conduction path of the battery, enabling the heat generated during battery operation to be more effectively dissipated through the top cover assembly, thereby improving the battery's thermal management and heat dissipation performance, extending the life of the lithium-ion battery and enhancing safety.

[0052] Specifically, the connection between the terminal post 22 and the positive electrode tab 41, and the pressing action of the clamping ring 23 on the terminal post 22, ensure the stable electrical connection of the lithium-ion battery during charging and discharging. The multi-directional arrangement of the sealing structure 24 (located between the hole wall of the through hole 211 and the terminal post 22, between the first end of the terminal post 22 and the cover plate 21, and between the clamping ring 23 and the cover plate 21) forms multiple sealing layers, effectively preventing electrolyte leakage and the intrusion of external moisture or impurities, improving the encapsulation sealing performance of the lithium-ion battery, and increasing the safety and service life of the lithium-ion battery. The clamping ring 23 is sleeved on the second end of the terminal post 22 and presses the terminal post 22 onto the cover plate 21 by riveting or other means. This not only enhances the connection strength between the terminal post 22 and the cover plate 21, but also further improves the structural stability of the top cover 20, enabling it to withstand internal pressure changes during the charging and discharging process of the lithium-ion battery and maintain the integrity of the top cover 20.

[0053] like Figure 4As shown, along the direction from the top cover 20 to the cylindrical shell 10, the through hole 211 includes a first hole section 2111, a second hole section 2112, and a third hole section 2113 connected in sequence. The inner diameter of the first hole section 2111 is larger than the inner diameter of the second hole section 2112, and the inner diameter of the second hole section 2112 is larger than the inner diameter of the third hole section 2113. This stepped hole design better accommodates and fixes the sealing structure 24. During the insertion and riveting process of the electrode post 22, the difference in hole diameter between different sections can compress the sealing structure 24, forming a multi-level seal, effectively preventing electrolyte leakage, and simultaneously enhancing the lithium-ion battery's protection against the external environment, thereby improving the safety and lifespan of the lithium-ion battery.

[0054] In this embodiment, the gradually decreasing diameter of each hole segment in the through hole 211, combined with the structure of the electrode post 22 and the pressure ring 23, can increase the structural strength of the top cover 20, thereby allowing the pressure ring 23 to more effectively fix the electrode post 22 during the riveting process, thus providing additional support when the internal pressure of the lithium-ion battery changes.

[0055] Optionally, along the direction from the top cover 20 to the cylindrical housing 10, the inner diameter of the first aperture section 2111 gradually decreases; and / or, at least a portion of the inner diameter of the second aperture section 2112 gradually decreases. This gradually decreasing aperture design helps to create a tighter seal. When the terminal post 22 passes through the through hole 211, the gradually decreasing aperture can more effectively compress the sealing structure 24, forming a multi-stage seal, reducing the risk of electrolyte leakage, enhancing the sealing performance of the lithium-ion battery package, and preventing the intrusion of external moisture or impurities, thereby improving the safety and lifespan of the lithium-ion battery.

[0056] In this embodiment, along the direction from the top cover 20 to the cylindrical shell 10, the inner diameter of the first hole section 2111 gradually decreases, and at least part of the inner diameter of the second hole section 2112 gradually decreases.

[0057] like Figure 6 As shown, along the direction from the top cover 20 to the cylindrical shell 10, the pressure ring 23 includes a first ring body 231, a second ring body 232, and a third ring body 233 connected in sequence. The outer diameter of the first ring body 231 is larger than the outer diameter of the second ring body 232, and the outer diameter of the second ring body 232 is larger than the outer diameter of the third ring body 233. The outer circumferential surface of the second ring body 232 is connected to the outer circumferential surface of the third ring body 233 through an annular plane 234. The third ring body 233, at least a portion of the second ring body 232, and the annular plane 234 are pressed against the sealing structure 24. In this way, the stepped structure design of the pressure ring 23, through the change of the outer diameter of the different ring bodies, can increase the contact area with the sealing structure 24 during the pressing process, thereby more effectively compressing the sealing structure 24, forming multiple seals, significantly enhancing the sealing performance between the top cover 20 and the cylindrical shell 10, and effectively preventing electrolyte leakage and the intrusion of external moisture or impurities.

[0058] Specifically, the aforementioned ring design of the pressure ring 23 (first ring 231, second ring 232, and third ring 233) and its gradually decreasing size increase the contact area and clamping force between it and the terminal post 22 and the cover plate 21, thereby improving the mechanical connection strength and structural stability of the top cover 20. It can withstand internal pressure changes during the charging and discharging of the lithium-ion battery, maintaining the integrity and reliability of the top cover 20. At the same time, a vertical force can be generated on the annular plane 234, thereby improving the clamping effect of the pressure ring 23 and enhancing the overall structural strength of the top cover 20.

[0059] Optionally, along the direction from the top cover 20 to the cylindrical housing 10, the outer diameter of the second ring 232 gradually decreases; and / or, the outer diameter of the third ring 233 gradually decreases. This gradual decrease in the outer diameter of the second ring 232 and / or the third ring 233 increases the contact area between them and the sealing structure 24 during the compression process, thereby forming a tighter seal to ensure the sealing performance between the top cover 20 and the cylindrical housing 10, effectively preventing electrolyte leakage and improving the stability and safety of the lithium-ion battery.

[0060] In this embodiment, along the direction from the top cover 20 to the cylindrical shell 10, the outer diameter of the second ring 232 gradually decreases, and the outer diameter of the third ring 233 gradually decreases.

[0061] like Figure 5 As shown, the pole post 22 includes a column 221 and a connecting plate 222. The column 221 passes through the through hole 211 and includes a first column segment 2211 and a second column segment 2212 connected to each other. The outer diameter of the first column segment 2211 is larger than the outer diameter of the second column segment 2212. The connecting plate 222 is connected to the end of the first column segment 2211 away from the second column segment 2212 and is connected to the positive electrode tab 41. The end of the second column segment 2212 away from the first column segment 2211 has a deformation hole 2213. Along the direction from the second column segment 2212 to the first column segment 2211, the diameter of the deformation hole 2213 gradually decreases to deform and compress the pressure ring 23 and the sealing structure 24 under pressure. In this way, the design of two cylindrical segments of different diameters (first cylindrical segment 2211 and second cylindrical segment 2212) of the cylindrical body 221, and the stable connection between the connecting plate 222 and the positive electrode tab 41, ensure the stability and reliability of the electrical connection between the internal cell assembly 40 and the external circuit. At the same time, the above connection method reduces contact resistance, prevents loosening of electrical connections, and improves the performance of lithium-ion batteries.

[0062] Specifically, the design of the deformation hole 2213 in the second column section 2212 allows the electrode post 22 to deform during riveting or pressing, thereby pressing the pressure ring 23 and the sealing structure 24. The gradual reduction in the diameter of the deformation hole 2213 helps the electrode post 22 to achieve an ideal deformation effect under pressure, enhancing the tightness of the sealing structure 24, effectively preventing electrolyte leakage and the intrusion of external moisture or impurities, and improving the sealing performance of the battery package. At the same time, the above-mentioned structural design of the electrode post 22, especially the setting of the deformation hole 2213 at the end of the second column section 2212, can maintain the structural integrity and stability of the battery when it is subjected to external impact or pressure, improving the mechanical strength and durability of the lithium-ion battery.

[0063] like Figure 7 As shown, the battery cell assembly 40 includes a negative electrode tab 42. Along the direction from the bottom cover 30 to the cylindrical housing 10, the bottom cover 30 includes a first plate 31, a second plate 32, and a third plate 33 connected sequentially. A first stepped surface 34 is formed at the connection between the first plate 31 and the second plate 32, and a second stepped surface 35 is formed at the connection between the second plate 32 and the third plate 33. The first plate 31 is located outside the cylindrical housing 10, the second plate 32 extends into the cylindrical housing 10 and its outer circumferential surface contacts the cavity wall, and the negative electrode tab 42 is connected to the third plate 33. This multi-level plate design of the bottom cover 30 (first plate 31, second plate 32, third plate 33), especially the formation of the first stepped surface 34 and the second stepped surface 35, helps optimize the battery packaging structure, enabling the bottom cover 30 to fit tightly into the cavity of the cylindrical housing 10, improving the mechanical stability between components, reducing the waste of internal battery space, and thus increasing the energy density of the lithium-ion battery.

[0064] Specifically, by directly connecting the negative electrode tab 42 to the third plate 33 of the bottom cover 30, the stability and reliability of the electrical connection are effectively improved, the contact resistance in the connection path is reduced, the efficient electrical transmission between the cell assembly 40 and the cylindrical housing 10 is ensured, the energy consumption inside the lithium-ion battery is reduced, and the battery efficiency is improved.

[0065] like Figure 1As shown, the battery cell assembly 40 also includes multiple electrode groups 43, each electrode group 43 comprising a positive electrode 431, a separator 432, and a negative electrode 433 connected in sequence. The multiple electrode groups 43 are stacked or wound sequentially. This arrangement simplifies the structure of the battery cell assembly 40, making it easier to manufacture and implement, thus reducing manufacturing costs and difficulty. Furthermore, it allows for more diverse and flexible formation methods to meet different usage requirements and operating conditions, improving the processing flexibility for workers. Simultaneously, the stacked or wound structure of the multiple electrode groups 43 effectively utilizes the internal space of the battery cell assembly 40, enabling the lithium-ion battery to accommodate more active materials, thereby achieving higher energy density within the same volume.

[0066] Specifically, the sequential connection of the positive electrode 431, the separator 432, and the negative electrode 433 constructs a stable electrochemical reaction pathway. The separator 432, as an intermediate layer, not only effectively separates the positive and negative electrodes to prevent internal short circuits but also ensures efficient ion conduction, thereby improving the charge-discharge efficiency and cycle performance of the lithium-ion battery.

[0067] Optionally, the electrolyte is a liquid electrolyte, a gel electrolyte, or a solid electrolyte.

[0068] This application also provides a lithium-ion battery processing method, applicable to the aforementioned lithium-ion battery, the lithium-ion battery processing method comprising:

[0069] Step S1: Insert the pole into the through hole of the cover plate, install the sealing structure between the pole and the hole wall, put a pressure ring on one end of the pole, and tighten the pole and pressure ring by riveting to form the top cover.

[0070] Step S2: Assemble the cylindrical housing and bottom cover, and install the battery cell assembly into the receiving cavity of the cylindrical housing so that the negative electrode tab of the battery cell assembly is electrically connected to the bottom cover;

[0071] Step S3: Inject electrolyte into the receiving cavity through the first opening end of the cylindrical shell. After the electrolyte injection is completed, install the top cover on the first opening end to seal the first opening end so that the positive electrode tab of the battery cell assembly is electrically connected to the electrode post of the top cover.

[0072] Specifically, by inserting a sealing structure between the terminal post and the through hole, and then using a riveting method to tighten the terminal post and the pressure ring, the sealing performance between the top cover and the cylindrical shell is ensured, effectively isolating external moisture and impurities, preventing electrolyte leakage, and improving battery safety and stability. The positive and negative terminals of the cell assembly are electrically connected to the terminal post of the top cover and the bottom cover, respectively, ensuring efficient electrical transmission between the cell assembly and the battery casing, thereby reducing contact resistance and improving the charge-discharge efficiency and cycle performance of the lithium-ion battery. Simultaneously, the above steps provide a simple and efficient battery assembly process. First, the top cover assembly is assembled; then, the cell assembly is installed into the receiving cavity of the cylindrical shell; finally, the electrolyte is injected and the top cover is sealed. This sequential and modular assembly method simplifies the production process, improves assembly efficiency and yield, and reduces production costs.

[0073] Example 2

[0074] The difference between the lithium-ion battery in Example 2 and Example 1 is that the connection method between the flat plate and the curved plate is different.

[0075] like Figure 8 As shown, the first flat plate 11 is directly connected to the first arc-shaped plate 12, the first flat plate 11 is directly connected to the second arc-shaped plate 14, the second flat plate 13 is directly connected to the first arc-shaped plate 12, and the second flat plate 13 is directly connected to the second arc-shaped plate 14. This connection method makes connecting the flat plate and the arc-shaped plate easier and simpler, reducing the processing difficulty.

[0076] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0077] A lithium-ion battery includes a cylindrical casing, a top cover, a bottom cover, and a cell assembly. The cylindrical casing includes a first flat plate, a first arc-shaped plate, a second flat plate, and a second arc-shaped plate connected end-to-end to form a receiving cavity. The first arc-shaped plate and / or the second arc-shaped plate protrude towards the side opposite to the receiving cavity. The top cover is disposed on the first open end of the cylindrical casing. The bottom cover is disposed on the second open end of the cylindrical casing. The cell assembly is disposed within the receiving cavity. By arranging the first and second flat plates parallel to each other and the first and / or second arc-shaped plates protruding towards the side opposite to the receiving cavity, the cylindrical casing forms an elliptical-like structure. This allows for a larger receiving cavity space without increasing the overall battery volume, thereby increasing the loading of active materials and solving the problem of low internal space utilization in lithium-ion batteries in related technologies, thus effectively improving the energy density of lithium-ion batteries. Meanwhile, by limiting the distance H1 between the first plate and the second plate, and the maximum distance D1 between the first arc plate and the second arc plate to satisfy the following relationships: H1≥2.0mm; and / or, D1>2.0mm; and / or, D1>H1, the cylindrical shell can ensure a certain thickness to ensure structural strength and safety, while also making the lithium-ion battery thinner and more suitable for the lightweight requirements of wearable devices.

[0078] Compared to traditional square or cylindrical batteries, the cylindrical casing of the lithium-ion battery in this application is better able to adapt to irregular spaces inside wearable devices, thus improving space utilization.

[0079] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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 the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0080] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0081] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0082] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lithium-ion battery, characterized in that, include: The cylindrical shell (10) includes a first flat plate (11), a first arcuate plate (12), a second flat plate (13), and a second arcuate plate (14) connected end to end to form a receiving cavity, wherein the first arcuate plate (12) and / or the second arcuate plate (14) protrude toward a side away from the receiving cavity; A top cover (20) is disposed on the first open end of the cylindrical shell (10); A bottom cover (30) is disposed on the second open end of the cylindrical shell (10); The battery cell assembly (40) is disposed within the receiving cavity; The first plate (11) and the second plate (13) are arranged parallel to each other, and there is a distance H1 between the first plate (11) and the second plate (13). The maximum distance D1 between the first arc plate (12) and the second arc plate (14) satisfies the following relationship: H1 ≥ 2.0 mm; and / or, D1 > 2.0 mm; and / or, D1 > H1.

2. The lithium-ion battery according to claim 1, characterized in that, The first arc-shaped plate (12) and the second arc-shaped plate (14) are symmetrically arranged about the center plane S1 of the cylindrical shell (10).

3. The lithium-ion battery according to claim 1, characterized in that, The first arc plate (12) and the second arc plate (14) are arranged concentrically.

4. The lithium-ion battery according to claim 1, characterized in that, The connection between the first flat plate (11) and the first arc-shaped plate (12) is transitioned by a first circular arc plate; and / or, The connection between the first flat plate (11) and the second arc-shaped plate (14) is transitioned by a second arc plate; and / or, The second flat plate (13) and the first arc-shaped plate (12) are connected by a third arc-shaped plate; and / or, The second flat plate (13) and the second arc plate (14) are connected by a fourth arc plate.

5. The lithium-ion battery according to claim 1, characterized in that, The battery cell assembly (40) includes a positive electrode tab (41), and the top cover (20) includes: Cover plate (21) has through hole (211); A pole post (22) is inserted into the through hole (211), and the first end of the pole post (22) is connected to the positive electrode tab (41); A pressure ring (23) is fitted over the second end of the pole post (22) to press the pole post (22) tightly onto the cover plate (21); The sealing structure (24) is located between the hole wall of the through hole (211) and the pole post (22), a portion of the sealing structure (24) is located between the first end of the pole post (22) and the cover plate (21), and another portion of the sealing structure (24) is located between the pressure ring (23) and the cover plate (21).

6. The lithium-ion battery according to claim 5, characterized in that, Along the direction from the top cover (20) to the cylindrical shell (10), the through hole (211) includes a first hole segment (2111), a second hole segment (2112), and a third hole segment (2114) connected in sequence. The inner diameter of the first hole segment (2111) is larger than the inner diameter of the second hole segment (2112), and the inner diameter of the second hole segment (2112) is larger than the inner diameter of the third hole segment (2114). The inner diameter of the first hole segment (2111) gradually decreases along the direction from the top cover (20) to the cylindrical shell (10), and / or, at least a portion of the inner diameter of the second hole segment (2112) gradually decreases.

7. The lithium-ion battery according to claim 5, characterized in that, Along the direction from the top cover (20) to the cylindrical shell (10), the pressure ring (23) includes a first ring body (231), a second ring body (232), and a third ring body (233) connected in sequence. The outer diameter of the first ring body (231) is larger than the outer diameter of the second ring body (232), and the outer diameter of the second ring body (232) is larger than the outer diameter of the third ring body (233). The outer circumferential surface of the second ring body (232) is connected to the outer circumferential surface of the third ring body (233) through an annular plane (234). The third ring body (233), at least a portion of the second ring body (232), and the annular plane (234) are pressed against the sealing structure (24). The outer diameter of the second ring body (232) gradually decreases along the direction from the top cover (20) to the cylindrical shell (10), and / or the outer diameter of the third ring body (233) gradually decreases.

8. The lithium-ion battery according to claim 5, characterized in that, The pole (22) includes: A column (221) is inserted into the through hole (211). The column (221) includes a first column segment (2211) and a second column segment (2212) that are connected to each other. The outer diameter of the first column segment (2211) is larger than the outer diameter of the second column segment (2212). A connecting plate (222) is connected to the end of the first column segment (2211) away from the second column segment (2212), and the connecting plate (222) is connected to the positive electrode tab (41); The second column segment (2212) has a deformation hole (2213) at the end away from the first column segment (2211). The diameter of the deformation hole (2213) gradually decreases along the direction from the second column segment (2212) to the first column segment (2211) so as to deform and press the pressure ring (23) and the sealing structure (24) under pressure.

9. The lithium-ion battery according to claim 1, characterized in that, The battery cell assembly (40) includes a negative electrode tab (42). Along the direction from the bottom cover (30) to the cylindrical housing (10), the bottom cover (30) includes a first plate (31), a second plate (32), and a third plate (33) connected in sequence. A first step surface (34) is formed at the connection between the first plate (31) and the second plate (32), and a second step surface (35) is formed at the connection between the second plate (32) and the third plate (33). The first plate (31) is located outside the cylindrical housing (10), the second plate (32) extends into the cylindrical housing (10) and its outer peripheral surface contacts the cavity wall of the receiving cavity, and the negative electrode tab (42) is connected to the third plate (33).

10. The lithium-ion battery according to claim 1, characterized in that, The battery cell assembly (40) also includes multiple electrode groups (43), each of the electrode groups (43) including a positive electrode (431), a separator (432) and a negative electrode (433) connected in sequence; wherein, the multiple electrode groups (43) are stacked or wound in sequence.

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