Individual cells and battery packs

Abstract

This utility model relates to the field of battery technology and discloses a single cell and a battery pack, which improves the effective connection area of ​​the current collector and enhances battery performance. The single cell includes: a housing having an inner cavity and a through hole; an electrode assembly disposed in the inner cavity; a terminal post passing through the through hole; and a current collector located axially between the electrode assembly and the terminal post, including a central portion connected to and electrically conductive with the terminal post and an edge structure connected to and electrically conductive with the electrode assembly; the edge structure includes at least two connecting portions and at least two welding portions, the connecting portions and welding portions circumferentially surrounding the central portion and alternately arranged; the welding portions and the central portion are respectively connected to the two ends of the connecting portions radially; a first gap is provided between the welding portion and the central portion, and a second gap is provided between the welding portion and the adjacent connecting portion; the first gap and the second gap penetrate the current collector axially, and the first gap between each welding portion and the central portion connects the welding portion to the second gap between the welding portion and the adjacent connecting portion.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a single battery cell and a battery pack. Background Technology

[0002] In pursuit of high energy density in batteries, some technical solutions use high-nickel ternary materials as the main cathode material. However, high-nickel ternary materials have poorer thermal stability compared to other cathode materials, leading to greater safety risks. To reduce these safety risks, a fusible link is typically added to the current collector inside the battery. This fusible link is more prone to melting due to overheating from overcurrent than other structural components, thus ensuring the battery's safety in use.

[0003] In related technologies, current collectors typically include a central welding area, an annular welding area surrounding the central welding area, and a fusion structure connecting the central welding area and the annular welding area. However, the fusion structure often results in a wide gap between the central welding area and the annular welding area. Since the overall area of ​​the current collector is limited, a wide gap occupies too much current collector area, leading to a reduction in the area of ​​the annular welding area. This, in turn, reduces the contact area between the annular welding area and the electrode assembly, increasing the battery impedance and degrading the battery's electrical performance. Utility Model Content

[0004] In view of this, the present invention provides a single cell battery and a battery pack to solve the problem that the reduced area of ​​the annular welding zone caused by the setting of the fusion structure in the current collector leads to a decrease in battery performance.

[0005] In a first aspect, this utility model provides a single-cell battery, comprising: a casing having two perpendicular axial, radial, and circumferential directions; the casing having an inner cavity and a through hole communicating with the inner cavity; an electrode assembly disposed in the inner cavity; a terminal post passing through the through hole; and a current collector comprising a central portion and an edge structure; the current collector is axially located between the electrode assembly and the terminal post; the central portion is connected to and electrically conductively connected to the terminal post; the edge structure is connected to and electrically conductively connected to the electrode assembly; the edge structure comprises at least two connecting portions and at least two welding portions, each connecting portion and each welding portion being alternately arranged around the central portion circumferentially; each welding portion connecting an adjacent connecting portion at a radially distant end from the central portion, and the outer edge of the central portion connecting an connecting portion at a radially close end to the central portion; each welding portion having a first gap with the central portion, and each welding portion having a second gap with an adjacent connecting portion; each first gap and each second gap penetrating the current collector axially, and the first gap between each welding portion and the central portion communicating with the second gap between the welding portion and the adjacent connecting portions.

[0006] Optionally, the projection of the central part onto a plane perpendicular to the axial direction is circular, and in the projection of the collector plate onto a plane perpendicular to the axial direction, the notch shape corresponding to each first gap is a strip extending along an arc.

[0007] Optionally, each connection extends radially and maintains a constant width, and in the projection of the collector plate onto a plane perpendicular to the axial direction, the notch shape corresponding to each second gap is a strip extending along a straight line.

[0008] Optionally, the orthographic projection of each welded part on a plane perpendicular to the axial direction is a fan shape, and in the projection of the collector plate on a plane perpendicular to the axial direction, the notch shape corresponding to each second gap is a strip extending radially.

[0009] Optionally, the central part and the edge structure are located in the same plane, the side of the central part opposite to the electrode assembly is coated with an insulating layer, the side of the welded part opposite to the pole post is coated with an insulating layer, and the connecting part is coated with an insulating layer on both sides in the axial direction.

[0010] Optionally, the central portion protrudes axially toward the pole relative to the welded portion, and at least a portion of the connecting portion protrudes axially toward the pole relative to the welded portion.

[0011] Optionally, the edge structure also includes multiple protrusions, each protruding axially toward the pole post, and each protrusion circumferentially surrounding the center and arranged alternately.

[0012] Optionally, it also includes an insulating sealing assembly, which includes a lower plastic part, a sealing ring, and an upper plastic part. The lower plastic part is disposed in the inner cavity and is connected to the inner wall of the housing facing the electrode assembly. The upper plastic part is connected to the outer wall of the housing facing away from the electrode assembly and is connected to the outer peripheral wall of the electrode post. The sealing ring is sleeved on the electrode post and abuts between the lower plastic part and the upper plastic part.

[0013] Optionally, it also includes a riveting block, which is disposed at the end of the pole away from the housing and connected to the outer peripheral wall of the pole.

[0014] Secondly, this utility model also provides a battery pack, including: the single battery cell as described above.

[0015] The technical solution of this utility model has at least the following advantages:

[0016] 1. The first gap on the current collector is located radially between the welded part and the center part. Therefore, the size of the connecting part will not affect the radial size of the first gap. This avoids the gap between the welded part and the center part being too large due to the setting of the connecting part, thereby increasing the effective area of ​​the welded part and the center part, reducing the battery impedance, and improving the battery performance.

[0017] 2. The second gap on the manifold is located circumferentially between the adjacent connection and weld, so the dimensions of the connection will not affect the circumferential dimension of the second gap. This design allows for more flexible dimensional settings of the connection, enabling it to meet various fusing conditions and improving applicability. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in 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 utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a current collector in the prior art;

[0020] Figure 2 This is a schematic diagram of the structure of a single battery according to an embodiment of the present utility model;

[0021] Figure 3 This is a cross-sectional view of a single battery cell according to an embodiment of the present utility model;

[0022] Figure 4 for Figure 3 A magnified view of part A in the diagram;

[0023] Figure 5 This is a schematic diagram of the structure of a collector disk according to an embodiment of the present utility model;

[0024] Figure 6 for Figure 5 A magnified view of part B in the diagram;

[0025] Figure 7 This is a partial cross-sectional view of a collector plate according to an embodiment of the present utility model;

[0026] Figure 8 This is a schematic diagram of the structure of a collector plate according to another embodiment of the present utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] 101. Central welding area; 102. Circumferential welding area; 103. Fusion structure; 104. Gap;

[0029] 1. Collector plate; 11. Center section; 12. Edge structure; 121. Connecting part; 122. Welding part; 13. First gap; 14. Second gap; 15. Protrusion; 2. Electrode post; 3. Electrode assembly; 4. Housing; 41. Inner cavity; 42. Through hole; 5. Lower plastic part; 6. Upper plastic part; 7. Sealing ring; 8. Riveting block;

[0030] Z, axial direction; R, radial direction; θ, circumferential direction. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0032] In related technologies, the configuration of the collector disk 1 is typically as follows: Figure 1 As shown, the current collector 1 includes a central welding area 101, an annular welding area 102 surrounding the central welding area 101, and a fusible structure 103 connecting the central welding area 101 and the annular welding area 102. The central welding area 101 is connected to the electrode post 2, and the annular welding area 102 is connected to the electrode assembly 3 (bare cell). In actual operation, to meet the overcurrent fusing requirements, the radial length of the fusible structure 103 is relatively large (usually >1mm), thus forming a relatively wide gap 104 between the central welding area 101 and the annular welding area 102. However, the overall area of ​​the current collector 1 is limited, and the wide gap 104 will occupy too much area of ​​the current collector 1, resulting in a reduction in the area of ​​the annular welding area 102. This reduces the contact area between the annular welding area 102 and the electrode assembly 3, increases the battery impedance, and degrades the battery's electrical performance.

[0033] To solve the above-mentioned technical problems, this utility model provides a single battery cell and a battery pack.

[0034] The following is combined Figures 2 to 8 The following describes embodiments of the present invention.

[0035] According to an embodiment of the present invention, a battery pack is provided, comprising one or more individual batteries. Specifically, as shown in the embodiment... Figures 2-4As shown, the single-cell battery includes a housing 4, an electrode assembly 3, a terminal post 2, and a current collector 1. The housing 4 has an inner cavity 41, and a through hole 42 communicating with the inner cavity 41. The housing 4 has two perpendicular axes Z, R, and θ. The electrode assembly 3 and the current collector 1 are disposed within the inner cavity 41, the terminal post 2 passes through the through hole 42, and the current collector 1 is located between the electrode assembly 3 and the terminal post 2 in the Z-axis direction. It can be understood that the single-cell battery of this invention can be a cylindrical battery.

[0036] The axial direction Z, radial direction R, and circumferential direction θ are mutually perpendicular. It should be noted that in all embodiments of this application, the axial direction Z refers to the direction indicated by the arrow in the accompanying drawings. It should be understood that reversing one or more of the axial direction Z, radial direction R, and circumferential direction θ will not substantially affect the single cell and battery pack provided in the embodiments of this application, nor will it lead to adverse results such as the inability to achieve the desired technical effect. The axial direction Z is the direction indicated by the straight line perpendicular to the side of the current collector 1 facing the electrode assembly 3. A cylindrical coordinate system is constructed with the straight line passing through the center of the current collector 1 and parallel to the axial direction Z as the axis. The circumferential direction θ refers to the direction of the tangent to the circle centered at the intersection of the aforementioned axis and the aforementioned plane, which is perpendicular to the axial direction Z. The radial direction R refers to the direction of the ray originating from the intersection of the aforementioned axis and the aforementioned plane within the aforementioned plane.

[0037] It should be understood that the concepts of axial direction Z, radial direction R, and circumferential direction θ are introduced in all embodiments of this application merely for the convenience of describing spatial positional relationships and should not be construed as limiting the scope of the embodiments of this application. Therefore, the fact that axial direction Z, radial direction R, and circumferential direction θ are mutually perpendicular can be reasonably interpreted, based on the actual technical scenario, as a nearly perpendicular directional relationship between each pair of axial direction Z, radial direction R, and circumferential direction θ, for example, the included angle between each pair of axial direction Z, radial direction R, and circumferential direction θ is in the range of 85°-95°... As long as the technical solution conforms to the spirit of this application or achieves the technical effect described in this application, it can be considered to fall within the scope defined by the appended claims.

[0038] Furthermore, such as Figure 5As shown, the collector plate 1 includes a central portion 11 and an edge structure 12. The central portion 11 is connected to and electrically conductive with the electrode post 2, and the edge structure 12 is connected to and electrically conductive with the electrode assembly 3. This invention does not specifically limit the connection method between the central portion 11 and the electrode post 2. Exemplarily, the central portion 11 and the electrode post 2 can be connected and electrically conductive by welding, bonding with conductive adhesive, etc., preferably by welding. This invention also does not specifically limit the connection method between the edge structure 12 and the electrode assembly 3. Exemplarily, the edge structure 12 and the electrode assembly 3 can be connected and electrically conductive by welding, bonding with conductive adhesive, etc., preferably by welding.

[0039] Furthermore, the edge structure 12 includes at least two connecting portions 121 and at least two welding portions 122, each connecting portion 121 and each welding portion 122 being arranged alternately around the central portion 11 in the circumferential direction θ. At both ends of the welding portion 122 in the circumferential direction θ, a one-to-one connection is made to the ends of the two connecting portions 121 adjacent to the welding portion 122 in the circumferential direction θ that are far from the central portion 11 in the radial direction R. The outer edge of the central portion 11 is connected to the ends of the connecting portions 121 that are close to the central portion 11 in the radial direction R. A first gap 13 is provided between each welding portion 122 and the central portion 11, and a second gap 14 is provided between each welding portion 122 and the adjacent connecting portion 121. Each first gap 13 and each second gap 14 penetrates the collector plate 1 in the axial direction Z, and the first gap 13 between each welding portion 122 and the central portion 11 connects to the second gap 14 between the welding portion 122 and the adjacent connecting portion 121.

[0040] In the single-cell batteries provided in the embodiments of this application, the current collector 1 has a thin sheet structure perpendicular to the axial direction Z. Therefore, the two ends of the welding part 122 in the circumferential direction θ are connected one-to-one to the ends of the two connecting parts 121 adjacent to the welding part 122 in the circumferential direction θ, which are far away from the center part 11 in the radial direction R. The outer edge of the center part 11 is connected to the end of the connecting part 121 in the radial direction R, which is close to the center part 11. Essentially, the thin sheet-like current collector 1 is divided into the center part 11, the welding part 122, and the connecting part 121 according to their functions. Of course, it can also be regarded as the side of the welding part 122 being connected to the side of the connecting part 121, and the side of the connecting part 121 being connected to the side of the center part 11.

[0041] Understandably, the welding portion 122 of the edge structure 12 is used to connect to and electrically conduct with the electrode assembly 3, and the connecting portion 121 is connected between the central portion 11 and the welding portion 122 to form a fluid channel for current between the central portion 11 and the welding portion 122, and to realize the overcurrent melting function when the current is overloaded.

[0042] In this embodiment, the first gap 13 on the current collector 1 is located radially R between the welded portion 122 and the center portion 11. Therefore, the size of the connecting portion 121 does not affect the size of the first gap 13 in the radial direction R, avoiding excessively large gaps between the welded portion 122 and the center portion 11 due to the connection portion 121. This increases the effective area of ​​the welded portion 122 and the center portion 11, reduces the battery impedance, and improves battery performance. Furthermore, the second gap 14 on the current collector 1 is located circumferentially θ between the adjacent connecting portion 121 and the welded portion 122. Therefore, the size of the connecting portion 121 does not affect the size of the second gap 14 in the circumferential direction θ. This arrangement allows for more flexible sizing of the connecting portion 121, enabling it to meet various melting conditions and improving applicability.

[0043] In some embodiments, the projection of the central portion 11 onto a plane perpendicular to the Z-axis is circular, and the notch shape corresponding to each first gap 13 in the projection of the current collector 1 onto the plane perpendicular to the Z-axis is a strip extending along an arc. Typically, the projection of the end of the electrode post 2 opposite to the current collector 1 onto the plane perpendicular to the Z-axis is circular or annular. In this embodiment, setting the central portion 11 as circular increases the effective connection area between the central portion 11 and the electrode post 2, further improving battery performance. Setting the first gap 13 as a strip extending along an arc simplifies the manufacturing process and facilitates the production of the current collector 1.

[0044] For example, the first gap 13 can be an arc extending along the circumferential direction θ. In the projection on the plane perpendicular to the axial direction Z, the projection of the central portion 11 is circular. The notch shape corresponding to the first gap 13 extends along the edge of the projection of the central portion 11. The projection of the current collector 1 on the plane perpendicular to the axial direction Z is also circular. The dimension of the current collector 1 in the axial direction Z, that is, the thickness of the current collector 1, can be less than 2 mm, and the radius of the current collector 1 is 5-100 mm. This satisfies the welding and current carrying requirements, and saves the assembly space of the housing 4 in the axial direction Z, thereby improving the energy density of the battery.

[0045] For example, the radius of the central part 11 accounts for 2%-50% of the radius of the collector plate 1. Of course, in some special cases, the radius of the central part 11 may also account for more than 50% or less than 2% of the radius of the collector plate 1, and its specific size can be adaptively adjusted according to the actual size of the pole post 2.

[0046] For example, such as Figure 6As shown, the dimension of the first gap 13 in the radial direction R, that is, the width of the first gap 13, is D1, which is greater than 0.1mm to meet the processing capacity requirements. Of course, under the adjustment allowed by the processing capacity, D1 can also be less than or equal to 0.1mm. In this utility model, the width D1 of the first gap 13 can be controlled as small as possible to maximize the effective connection area between the central part 11 and the welded part 122. As long as D1 is greater than 0, the spacing function between the central part 11 and the welded part 122 can be achieved.

[0047] Furthermore, in some embodiments, each connecting portion 121 extends radially R while maintaining a constant width; that is, the projection of the connecting portion 121 onto a plane perpendicular to the axial direction Z is strip-shaped. Also, in the projection of the current collector 1 onto the plane perpendicular to the axial direction Z, the notch shape corresponding to each second gap 14 is a strip extending along a straight line. In this embodiment, both the connecting portion 121 and the second gap 14 are strip-shaped, facilitating manufacturing. Furthermore, the strip shape of the connecting portion 121 makes it easier to melt under high current conditions than other parts, achieving overcurrent fuse functionality and improving battery safety performance.

[0048] For example, such as Figure 6 As shown, the connecting part 121 is a strip extending radially R. The second gaps 14 on both sides of the connecting part 121 are parallel to each other to ensure that the connecting part 121 has a stable and uniform rated fusing current. The dimension of the second gap 14 in the circumferential direction θ, that is, the width of the second gap 14, is D2. D2 can be 0.1mm-10mm. Of course, under the adjustment allowed by processing capacity, D2 can also be less than or equal to 0.1mm. In this utility model, the width D2 of the second gap 14 can be controlled as small as possible to maximize the effective connection area of ​​the welding part 122. As long as D2 is greater than 0, the spacing function between the welding part 122 and the connecting part 121 can be achieved.

[0049] Among them, such as Figure 6 As shown, the dimension of the connecting part 121 in the circumferential direction θ, that is, the width of the connecting part 121, is D3. For example, D3 can be 1mm-80mm. The dimension of the connecting part 121 in the radial direction R, that is, the length of the connecting part 121, depends on the size of the current collector 1. The length of the connecting part 121 can be 0 or equal to the radius of the current collector 1, as long as it can connect between the welding part 122 and the center part 11 to achieve the function of overcurrent. The overcurrent area of ​​each connecting part 121 is S, that is... Figure 7 The area of ​​each shaded region in the diagram is S( Figure 7 The illustrated embodiment has three connecting portions 121, each with a flow-through area of ​​S. For example, the area S of the connecting portion 121 can be 0.1 mm². 2 -200mm 2 .

[0050] Understandably, in the technical solution of this utility model, the setting of the connecting part 121 is highly flexible, and the setting size and area of ​​the connecting part 121 can be adaptively adjusted according to the specific fusing conditions of the battery.

[0051] In some embodiments, the orthographic projection of each weld portion 122 onto a plane perpendicular to the Z-axis is fan-shaped, and in the projection of the current collector 1 onto the plane perpendicular to the Z-axis, the notch shape corresponding to each second gap 14 is a strip extending radially R. The fan-shaped configuration of the weld portion 122 increases the projected area of ​​the weld portion 122 onto the plane perpendicular to the Z-axis, thereby maximizing the effective connection area between the weld portion 122 and the electrode assembly 3, specifically the welding area between the two, further improving battery performance. Furthermore, the strip shape of the second gaps 14 facilitates manufacturing.

[0052] In some embodiments, such as Figure 5 , Figure 7 and Figure 8 In the illustrated embodiment, the projection of the central portion 11 onto the plane perpendicular to the Z-axis is circular, the projection of the connecting portion 121 onto the plane perpendicular to the Z-axis is strip-shaped, and the projection of the welded portion 122 onto the plane perpendicular to the Z-axis is fan-shaped. The length of the connecting portion 121 is less than the radius of the collector plate 1, and two adjacent welded portions 122 are connected at the end of the connecting portion 121 radially R away from the central portion 11, thus further increasing the connection area of ​​the welded portions 122.

[0053] For example, the central part 11, the connecting part 121 and the welding part 122 can be integrally formed, which has a simple structure and is easy to process and manufacture.

[0054] In some embodiments, three connecting portions 121 and three welding portions 122 are provided. Each connecting portion 121 and each welding portion 122 is arranged alternately around the central portion 11 along the circumferential direction θ. This arrangement can ensure both the overcurrent capacity of the connecting portion 121 and the deformation resistance of the connecting portion 121, thereby reducing or even eliminating the risk of bending of the connecting portion 121.

[0055] Of course, in some embodiments not shown in the figures, the connecting part 121 and the welding part 122 may be provided in two, four, five or other quantities, as long as the number of both is greater than or equal to two.

[0056] Furthermore, in some embodiments, the central portion 11 and the edge structure 12 are located in the same plane. The side of the central portion 11 opposite to the electrode assembly 3 is coated with an insulating layer, the side of the welding portion 122 opposite to the electrode post 2 is coated with an insulating layer, and both sides of the connecting portion 121 in the axial Z direction are coated with an insulating layer. The fact that the central portion 11 and the edge structure 12 are located in the same plane reduces the size of the current collector 1 in the axial Z direction, thereby saving assembly space within the housing and increasing the battery's energy density.

[0057] In other embodiments, the central portion 11 protrudes relative to the welded portion 122 in the axial direction Z towards the pole post 2, and at least a portion of the connecting portion 121 protrudes relative to the welded portion 122 in the axial direction Z towards the pole post 2. This configuration eliminates the need for coating an insulating layer, simplifies the manufacturing process, and reduces costs.

[0058] In some embodiments, such as Figure 8 As shown, the edge structure 12 also includes a plurality of protrusions 15, each protruding along the axial direction Z of the pole post 2, and each protrusion 15 surrounding the center part 11 in the circumferential direction θ and being alternately arranged. The protrusions 15 can increase the strength of the edge structure 12 and facilitate the installation of the collector plate 1.

[0059] The protrusion 15 can be disposed on the welding portion 122 and offset from the connecting portion 121 along the circumferential direction θ. Exemplarily, the protrusion 15 can extend radially R and maintain a constant width. Exemplarily, the protrusion 15 can be integrally formed on the welding portion 122 and protrude along the direction of the axial Z-phase pole 2.

[0060] Furthermore, in some embodiments, such as Figure 4 As shown, the single-cell battery also includes an insulating and sealing assembly, which includes a lower plastic component 5, a sealing ring 7, and an upper plastic component 6. The lower plastic component 5 is disposed within the inner cavity 41 and is connected to the inner wall of the housing 4 facing the electrode assembly 3. The upper plastic component 6 is connected to the outer wall of the housing 4 facing away from the electrode assembly 3 and to the outer peripheral wall of the electrode post 2. The sealing ring 7 is fitted onto the electrode post 2 and abuts against the lower plastic component 5 and the upper plastic component 6. The arrangement of the lower plastic component 5, the sealing ring 7, and the upper plastic component 6 ensures both the sealing performance of the single-cell battery and the insulation between the electrode post 2 and the housing 4, as well as between the housing 4 and the current collector 1.

[0061] In some embodiments, the single battery cell further includes a riveting block 8, which is disposed at the end of the terminal post 2 away from the housing 4 and connected to the outer peripheral wall of the terminal post 2, so as to facilitate the connection and electrical conduction between the terminal post 2 and external components through the riveting block 8. At least a portion of the structure of the aforementioned upper plastic part 6 can be connected between the outer wall of the housing 4 and the riveting block 8.

[0062] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A single-cell battery, characterized in that, include: The housing (4) has two perpendicular axial (Z), radial (R) and circumferential (θ) directions. The housing (4) has an inner cavity (41) and a through hole (42) that connects to the inner cavity (41). Electrode assembly (3), the electrode assembly (3) being disposed in the inner cavity (41); The pole post (2) is inserted through the through hole (42); A collector plate (1) includes a central portion (11) and an edge structure (12); the collector plate (1) is located in the axial direction (Z) between the electrode assembly (3) and the pole post (2), the central portion (11) is connected to the pole post (2) and electrically conductive, and the edge structure (12) is connected to the electrode assembly (3) and electrically conductive; the edge structure (12) includes at least two connecting portions (121) and at least two welding portions (122), each of the connecting portions (121) and each of the welding portions (122) surrounds the central portion (11) in the circumferential direction (θ) and is alternately arranged; the welding portion (122) connects the adjacent connecting portions (121) at one end away from the central portion (11) in the radial direction (R), and the outer edge of the central portion (11) connects the connecting portion (121) at one end close to the central portion (11) in the radial direction (R); Each of the welded portions (122) is provided with a first gap (13) between itself and the center portion (11), and each of the welded portions (122) is provided with a second gap (14) between itself and the adjacent connecting portion (121). The first gap (13) and the second gap (14) both penetrate the collector plate (1) in the axial direction (Z). The first gap (13) between each welded portion (122) and the center portion (11) connects the welded portion (122) with the second gap (14) between the welded portion (122) and the adjacent connecting portion (121).

2. The single-cell battery according to claim 1, characterized in that, The projection of the central part (11) onto the plane perpendicular to the axis (Z) is circular, and in the projection of the collector plate (1) onto the plane perpendicular to the axis (Z), the notch shape corresponding to each of the first gaps (13) is a strip extending along the arc.

3. The single-cell battery according to claim 2, characterized in that, Each of the connecting portions (121) extends along the radial direction (R) and maintains a constant width, and in the projection of the collector plate (1) onto a plane perpendicular to the axial direction (Z), the notch shape corresponding to each of the second gaps (14) is a strip extending along a straight line.

4. The single-cell battery according to claim 2, characterized in that, The orthographic projection of each of the welded portions (122) on the plane perpendicular to the axis (Z) is fan-shaped, and in the projection of the collector plate (1) on the plane perpendicular to the axis (Z), the notch shape corresponding to each of the second gaps (14) is a strip extending along the radial direction (R).

5. The single-cell battery according to any one of claims 1-4, characterized in that, The central portion (11) and the edge structure (12) are located in the same plane. The side of the central portion (11) opposite to the electrode assembly (3) is coated with an insulating layer. The side of the welding portion (122) opposite to the pole post (2) is coated with an insulating layer. The connecting portion (121) is coated with an insulating layer on both sides in the axial direction (Z).

6. The single-cell battery according to any one of claims 1-4, characterized in that, The central portion (11) protrudes from the welded portion (122) in the direction of the pole post (2) along the axial direction (Z), and at least a portion of the connecting portion (121) protrudes from the welded portion (122) in the direction of the pole post (2) along the axial direction (Z).

7. The single-cell battery according to any one of claims 1-4, characterized in that, The edge structure (12) also includes a plurality of protrusions (15), each of which protrudes along the axial direction (Z) toward the pole post (2), and each of the protrusions (15) surrounds the center part (11) along the circumferential direction (θ) and is arranged alternately.

8. The single-cell battery according to any one of claims 1-4, characterized in that, It also includes an insulating sealing assembly, which includes a lower plastic part (5), a sealing ring (7), and an upper plastic part (6). The lower plastic part (5) is disposed in the inner cavity (41) and is connected to the inner wall of the housing (4) facing the electrode assembly (3). The upper plastic part (6) is connected to the outer wall of the housing (4) facing away from the electrode assembly (3) and is connected to the outer peripheral wall of the pole post (2). The sealing ring (7) is sleeved on the pole post (2) and abuts between the lower plastic part (5) and the upper plastic part (6).

9. The single-cell battery according to any one of claims 1-4, characterized in that, It also includes a riveting block (8), which is disposed at the end of the pole post (2) away from the housing (4) and connected to the outer peripheral wall of the pole post (2).

10. A battery pack, characterized in that, include: The single-cell battery as described in any one of claims 1-9.

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