Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries. The single battery comprises a cover plate assembly and an electrode assembly, the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction, the electrode assembly comprises an electrode main body and a tab which are connected with each other, the cover plate assembly comprises a cover plate body and a pole, the pole is arranged on the cover plate body, and a first through hole is formed in the pole in the thickness direction; the single battery further comprises a connecting piece, the connecting piece comprises a first section and a second section, the first section penetrates through the first hole and is connected with the pole, the first section covers and seals the first hole, and the second section is arranged on the side, facing the electrode body, of the cover plate body and is connected with the first section and the tab. By arranging the connecting piece with the n-shaped structure and forming the first hole in the pole, the connecting piece does not need to be bent in the process of being connected with the tab and the pole, and the first section of the connecting piece can be accommodated in the first hole, so that the occupation of the internal space of the battery is reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a single cell and a battery pack. Background Art

[0002] As lithium-ion battery technology matures, it is widely used as a power battery in electric vehicles. However, the pole and tab in the battery cover assembly are usually connected by a connecting piece, which needs to be bent after welding to the tab. Summary of the Invention

[0003] Purpose of the invention: An embodiment of the present application provides a single cell battery, aiming to overcome the current technical problem of bending of the connecting piece and occupying the internal space of the battery; another purpose of the embodiment of the present application is to provide a battery pack.

[0004] Technical solution: The present application discloses a single battery cell, comprising: a cover plate assembly and an electrode assembly, wherein the electrode assembly is disposed on one side of the cover plate assembly in the thickness direction thereof, the electrode assembly comprising an electrode body and a terminal lug connected thereto, the cover plate assembly comprising a cover plate body and a terminal post, the terminal post being disposed on the cover plate body, the terminal post having a first through hole formed therethrough along the thickness direction;

[0005] The single battery also includes a connecting piece, which includes a first section and a second section. The first section is inserted into the first hole and connected to the pole. The first section covers the first hole. The second section is arranged on the side of the cover body facing the electrode body and connects the first section and the pole ear respectively.

[0006] In some embodiments, the first section includes a first wall and multiple second walls, the first wall connects the pole and covers the first hole, the multiple second walls are arranged circumferentially and connected to the side of the first wall facing the electrode assembly, the first wall and the multiple second walls form a main body groove, and the second wall is connected to the second section at an end away from the first wall.

[0007] In some embodiments, the cover plate assembly further includes a first welding portion connecting an inner wall of the first hole and the first wall;

[0008] And / or, the first welding portion connects the inner wall of the first hole and the plurality of second walls.

[0009] In some embodiments, the first wall has a wall thickness dimension of d1 mm, the second wall has a wall thickness dimension of d2 mm, and the second section has a wall thickness dimension of d3 mm, satisfying: 1.5≤d1≤3.2, 1.2≤d2≤2.0, 0.45≤d3≤1.2.

[0010] In some embodiments, the electrode tab includes a gathered segment and a connecting segment, wherein the gathered segment is connected to the electrode body, the connecting segment is connected to the second segment, and the gathered segment is connected to the connecting segment at an end away from the electrode body.

[0011] In some embodiments, the connecting section is connected to a side of the second section facing away from the electrode body, and the retracted section is spaced apart from the second section.

[0012] In some embodiments, the cover body is provided with an assembly hole along the thickness direction;

[0013] The pole includes a main body, a first connecting portion, and a second connecting portion, wherein the main body is inserted into the assembly hole, the first connecting portion is arranged on one side of the cover body along the thickness direction, and surrounds and connects the main body, the second connecting portion is arranged at one end of the main body away from the first connecting portion along the thickness direction, and forms a limiting groove with the main body, the first hole passes through the main body and the second connecting portion along the thickness direction, and on a plane perpendicular to the thickness direction, the orthographic projection of the limiting groove is located outside the orthographic projection of the first hole;

[0014] a welding block, disposed on a side of the cover body away from the first connecting portion and partially embedded in the limiting groove;

[0015] The cover plate body is sandwiched between the first connecting portion and the welding block.

[0016] In some embodiments, the second connecting portion has a riveted section, and the riveted section is protruded on a side of the second connecting portion away from the first hole;

[0017] The welding block includes a convex portion, which is arranged on a side of the welding block facing the second connecting portion and is embedded in the limiting groove;

[0018] In the thickness direction, the protrusion abuts against the riveting section.

[0019] In some embodiments, the protrusion has a first surface, the first surface is located on a side of the protrusion away from the main body, and the limiting groove has a second surface, the second surface is arranged opposite to the first surface;

[0020] The cover plate assembly further includes a second welding portion connecting the first surface and the second surface.

[0021] An embodiment of the present application further discloses a battery pack, comprising a single battery as described in the above embodiment.

[0022] Beneficial effects: The single cell battery in the embodiment of the present application includes: a cover plate assembly and an electrode assembly, wherein the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction thereof, the electrode assembly includes an electrode body and a pole tab connected to each other, the cover plate assembly includes a cover plate body and a pole post, the pole post is arranged on the cover plate body, and the pole post is provided with a first through hole along the thickness direction; the single cell battery also includes a connecting piece, the connecting piece includes a first section and a second section, the first section is arranged in the first hole and connected to the pole post, the first section covers the first hole, and the second section is arranged on the side of the cover plate body facing the electrode body, and respectively connects the first section and the pole tab. By providing a connecting piece with an "X" structure and providing a first hole on the pole post, the connecting piece does not need to be bent during the connection process with the pole tab and the pole post, and the first section of the connecting piece can be accommodated in the first hole, thereby reducing the space occupied by the internal battery.

[0023] The battery pack disclosed in the embodiment of the present application includes the single battery as described in the above embodiment, and thus can have all the technical features and technical effects of the above single battery, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic diagram of the three-dimensional structure of a single cell according to an embodiment of the present application;

[0026] Figure 2 This is a schematic diagram of the three-dimensional structure of the cover plate assembly in the single cell of the embodiment of the present application;

[0027] Figure 3 This is a schematic top view of the structure of a single cell according to an embodiment of the present application;

[0028] Figure 4 for Figure 3 Schematic cross-sectional view along the AA direction;

[0029] Figure 5 for Figure 3 A schematic cross-sectional view along the BB direction;

[0030] Figure 6 for Figure 4 A partial enlarged schematic diagram of point C in the middle;

[0031] Figure 7 This is a schematic diagram of the connection relationship between the electrode assembly and the connecting piece in the single battery of the embodiment of the present application;

[0032] Figure 8 This is a schematic top view of a single battery cell in an embodiment of the present application after the electrode assembly and the connecting piece are connected;

[0033] Figure 9 for Figure 8 Schematic cross-sectional view along the DD direction;

[0034] Figure 10 This is a schematic diagram of the three-dimensional structure of a cover plate assembly in a single cell according to another embodiment of the present application;

[0035] Figure 11 This is a schematic cross-sectional view of a single cell along the AA direction according to another embodiment of the present application;

[0036] Figure 12 for Figure 11 A partial enlarged schematic diagram of point E in the middle;

[0037] Figure 13 This is an exploded cross-sectional diagram of the welding block and the terminal in the single battery of the embodiment of the present application.

[0038] Description of reference numerals:

[0039] 10. Cover plate assembly; 20. Electrode assembly; 110. Cover plate body; 120. Electrode column; 121. Main body; 122. First connecting portion; 123. Second connecting portion; 124. Restricting groove; 125. Riveted section; 126. Second surface; 130. Connecting piece; 131. First section; 132. Second section; 140. First welding portion; 150. Welding block; 151. Protrusion; 152. First surface; 160. Second welding portion; 210. Electrode body; 220. Electrode tab; 221. Retracted section; 222. Connecting section; 1100. Assembly hole; 1200. First hole; 1300. Body groove; 1311. First wall; 1312. Second wall

[0040] X, thickness direction. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of this application.

[0042] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly defined. Terms such as "first", "second", and "third" are simply names for parts or embodiments for the convenience of description, and do not imply that there is an order of importance between parts or embodiments.

[0043] It should also be noted that in the drawings of the present application, the arrow marked X indicates the thickness direction X. In the description of the present application, the thickness direction X is introduced to more clearly define the structure and relative position relationship of each component in the single cell.

[0044] As a preface to the embodiments of the present application, the poles 120 in the current battery cover assembly 10 are mostly solid structures, which are relatively expensive; the connecting piece 130 welded to the pole tab 220 needs to be bent, which occupies more internal space of the battery, and there is a risk of tearing of the pole tab 220 during the bending process of the connecting piece 130, resulting in a low yield and insufficient product competitiveness.

[0045] In view of this, an embodiment of the present application provides a single cell battery, aiming to solve at least one of the above-mentioned technical problems.

[0046] See also Figures 1 to 4 As shown, the single cell disclosed in the embodiment of the present application includes: a cover assembly 10 and an electrode assembly 20, the electrode assembly 20 is arranged on one side of the cover assembly 10 in the thickness direction X, the electrode assembly 20 includes a tab 220, the cover assembly 10 includes a cover body 110 and a pole 120, the pole 120 is arranged on the cover body 110, and the pole 120 is provided with a through first hole 1200 along the thickness direction X; the single cell also includes a connecting piece 130, as shown Figure 4 and Figure 6As shown, the connecting piece 130 includes a first section 131 and a second section 132. The first section 131 is inserted into the first hole 1200 and connected to the electrode 120. The first section 131 covers the first hole 1200. The second section 132 is arranged on the side of the cover body 110 facing the electrode assembly 20 and connects the first section 131 to the electrode tab 220. Specifically, the single cell also includes a shell, which is used to provide mechanical support and containment for the electrode assembly 20, protecting it from environmental influences and preventing physical deformation and corrosion. The cover assembly 10 can cover the shell and seal the internal space of the shell. At the same time, the cover assembly 10 is used to connect the electrode assembly 20 with the external circuit to achieve current transmission.

[0047] It should be understood that by providing a through-hole 1200 in the electrode 120, the second section 132 of the connecting sheet 130 can be welded to the tab 220. The first section 131 of the connecting sheet 130 can be embedded in the first hole 1200 and connected to the electrode 120, thereby connecting the connecting sheet 130 to the tab 220 and the electrode 120. During this connection process, the connecting sheet 130 does not need to be bent, reducing the risk of tearing the tab 220 and improving production yield. Furthermore, the first hole 1200 provided in the electrode 120 significantly reduces the weight of the electrode 120, achieving a lightweight battery design. After passing through the first hole 1200, the second section 132 of the connecting sheet 130 can be connected to the electrode 120 and seal the first hole 1200, ensuring the sealing of the entire single cell structure. Furthermore, the second section 132 of the connecting sheet 130 can be directly welded to the busbar on the side facing away from the electrode assembly 20, shortening the current transmission path and reducing the internal resistance of the product.

[0048] The connecting piece 130 is formed as a single piece by extrusion. The connecting piece 130 includes a first section 131 and a second section 132 connected to each other. The first section 131 is raised relative to the second section 132. The first section 131 can be accommodated in the first hole 1200, reducing the internal space occupied by the battery. Its assembly structure is more stable and the spatial layout is more compact and reasonable. At the same time, the first hole 1200 provides a positioning for the installation of the connecting piece 130, reducing the difficulty of assembly, improving production efficiency, and helping to ensure product consistency and quality stability. The three-dimensional structure of the connecting piece 130 can form a stable electrical connection path between the pole 120 and the tab 220, while also making the mechanical structure of the entire single cell more stable.

[0049] The first hole 1200 formed in the terminal 120 increases the contact area between the connecting piece 130 and the terminal 120, reducing contact resistance and energy loss during current transmission, thereby ensuring stable current transmission during battery operation. Furthermore, the first hole 1200 acts as a limiter for the first section 131 of the connecting piece 130, preventing the connecting piece 130 from shifting or loosening when the battery is subjected to external forces. This enhances the reliability of the battery structure and improves the stability and safety of the battery during use.

[0050] Preferably, the first section 131 of the connecting piece 130 is provided with a chamfered structure to facilitate assembly of the first section 131 of the connecting piece 130 with the first hole 1200 .

[0051] See also Figure 2 and Figure 6 As shown, in some embodiments, the first section 131 includes a first wall 1311 and a plurality of second walls 1312, the first wall 1311 is connected to the pole 120 and covers the first hole 1200, the plurality of second walls 1312 are circumferentially arranged and connected to the side of the first wall 1311 facing the electrode assembly 20, the first wall 1311 and the plurality of second walls 1312 form a main body groove 1300, and the second wall 1312 is connected to the second section 132 at an end away from the first wall 1311. It should be understood that the first section 131 is surrounded by a first wall 1311 and multiple second walls 1312 to form a boss structure. The first wall 1311 is connected to the pole 120 and can cover the first hole 1200 to ensure the sealing inside the shell. The multiple second walls 1312 are arranged along the circumference and connected to the hole walls of the first hole 1200 of the pole 120 to form a stable current transmission path. At the same time, a relatively stable overall structure is formed in the first hole 1200 to better withstand external forces. For example, when the battery is subjected to vibration, extrusion, etc., the connecting piece 130 is not easy to loosen or fall off, thereby enhancing the mechanical structural strength of the single cell and improving the durability and safety of the battery.

[0052] At the same time, the first wall 1311 is connected to multiple second walls 1312 and forms a main body groove 1300. The main body groove 1300 can provide more heat dissipation space in the connection area between the connecting plate 130 and the pole 120, thereby improving the stability and reliability of the electrical connection of the single cell and ensuring smooth current transmission during operation of the battery.

[0053] See also Figure 6As shown, in some embodiments, the cover plate assembly 10 further includes a first welding portion 140, which connects the inner wall of the first hole 1200 and the first wall 1311; and / or, the first welding portion 140 connects the inner wall of the first hole 1200 and the plurality of second walls 1312. It should be understood that by having the first section 131 of the connecting piece 130 pass through the first hole 1200 of the pole 120 and by having the first welding portion 140 connect the first wall 1311 and the inner wall of the first hole 1200, a reliable mechanical and electrical connection is formed between the connecting piece 130 and the pole 120.

[0054] Furthermore, the first welding portion 140 connects the inner wall of the first hole 1200 and the first wall 1311, and at the same time connects the inner wall of the first hole 1200 and the plurality of second walls 1312 to increase the sealing path and connection tightness between the connecting piece 130 and the pole 120. The first welding portion 140 fills the gap between the inner wall of the first hole 1200 and the first section 131 to prevent gas or liquid from penetrating through the gap. The first welding portion 140 can withstand large external forces and prevent relative displacement between the connecting piece 130 and the pole 120. At the same time, the second section 132 of the connecting piece 130 connects the first section 131 and the pole lug 220, forming a complete connection path from the pole lug 220 to the pole 120, ensuring a stable connection between the electrode assembly 20 and the cover plate assembly 10.

[0055] See also Figures 7 to 9 As shown, in some embodiments, the first wall 1311 has a wall thickness dimension d1 mm, the second wall 1312 has a wall thickness dimension d2 mm, and the second segment 132 has a wall thickness dimension d3 mm, satisfying the following conditions: 1.5 ≤ d1 ≤ 3.2, 1.2 ≤ d2 ≤ 2.0, and 0.45 ≤ d3 ≤ 1.2. It should be understood that the thickness dimension of the first wall 1311 and the wall thickness dimension of the second wall 1312 in this embodiment refer to the distance between the inner and outer side surfaces of the portion of the connecting piece 130 that encloses the body groove 1300. Specifically, the wall thickness dimension of the first wall 1311 refers to the dimension along the thickness direction X, and the thickness dimension of the second wall 1312 refers to the radial width dimension on a plane perpendicular to the thickness direction X. The wall thickness dimension of the second segment 132 refers to the dimension of the second segment 132 along the thickness direction X.

[0056] By setting different wall thicknesses at different locations on the connecting piece 130, the connecting piece 130 is divided into different functional areas. The first wall 1311 needs to withstand internal battery pressure and external mechanical stress. By controlling the wall thickness of the first wall 1311 within the range of 1.5mm to 3.2mm, the first wall 1311 meets the deformation threshold. Furthermore, the first wall 1311 is directly welded to the busbar and is controlled to have sufficient thickness to provide structural support and load-bearing capacity. The second wall 1312, as a circumferential support structure, needs to withstand the thermal and assembly stresses generated by welding to the inner wall of the first hole 1200. By controlling the wall thickness of the second wall 1312 within the range of 1.2mm to 2.0mm, the second wall 1312 has sufficient structural strength and stability to avoid thermal deformation caused by welding. The third wall transmits current and withstands the tensile force of the tab 220. By controlling the wall thickness of the third wall within the range of 0.45mm to 1.2mm, the third wall balances conductivity and tensile strength.

[0057] Specifically, d1 can be any value selected from the group consisting of 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, and 3.2mm, or a range between two values. A larger d1 increases the structural strength of the first wall 1311, ensuring a better seal between the first wall 1311 and the terminal 120 and increasing the internal pressure limit of the battery. A smaller d1 facilitates a lightweight battery design and reduces costs.

[0058] Specifically, d2 can be any value among 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, or a range value between two values. When d2 is larger, the connection stability between the second wall 1312 and the pole 120 is higher, the structural rigidity of the second wall 1312 surrounding the body groove 1300 is enhanced, the mechanical / electrical connection between the connecting piece 130 and the electrode assembly 20 is more stable, and the contact resistance fluctuation under vibration conditions is reduced. In addition, when d2 is larger, the thermal conductivity of the second wall 1312 is higher, so as to accelerate the transfer of heat from the pole ear 220 and improve the stability of the electrical connection. When d2 is smaller, the internal space of the first hole 1200 occupied by the second wall 1312 is reduced, thereby improving space utilization and reducing material costs.

[0059] Specifically, d3 can be any value among 0.45mm, 0.55mm, 0.65mm, 0.75mm, 0.85mm, 0.95mm, 1.05mm, 1.15mm, and 1.2mm, or a range between two values. A larger d3 increases the current-conducting cross-sectional area of ​​the second segment 132, reduces the internal resistance of the connecting piece 130, and improves charge and discharge efficiency. Simultaneously, the mechanical strength of the second segment 132 is enhanced, and the fatigue resistance of the connection point between the tab 220 and the second segment 132 is improved, extending the battery life. Furthermore, the welding redundancy between the tab 220 and the second segment 132 is increased, reducing the risk of welding failure between the connecting piece 130 and the tab 220. A smaller d3 reduces the material usage of the connecting piece 130, lowering costs. Furthermore, assembly compatibility is improved, preventing excessive rigidity in the second segment 132 and reducing assembly stress concentration.

[0060] See also Figure 9 As shown, in some embodiments, the tab 220 includes a gathered section 221 and a connecting section 222. The gathered section 221 is connected to the electrode body 210, and the connecting section 222 is connected to the second section 132. The gathered section 221 is connected to the connecting section 222 at the end away from the electrode body 210. It should be understood that the gathered section 221 can guide the current dispersed on the electrode body 210 to the connecting section 222. At the same time, the gathered section 221 is connected to the connecting section 222 at the end away from the electrode body 210, so that the tab 220 serves as a transition and support between the electrode body 210 and the connecting sheet 130. The gathered section 221 can concentrate the stress generated by the electrode body 210 at the connection between it and the connecting section 222, preventing the stress from directly acting on the connection between the electrode body 210 and the connecting sheet 130, thereby enhancing the overall structural stability of the electrode assembly 20.

[0061] The gathered section 221 collects current from the electrode body 210. Due to its large contact area with the electrode body 210, it can evenly collect current generated in different parts of the electrode body 210. The current is then converged to the connecting section 222 through the gathered section 221, and then transmitted to the second section 132 of the connecting piece 130 through the connecting section 222. This structure ensures a gradual convergence and transition of current as it is transmitted from the electrode body 210 to the connecting piece 130, preventing current concentration in a localized area. This improves the uniformity of current distribution and contributes to enhanced battery performance and lifespan.

[0062] See also Figures 4 to 6As shown, in some embodiments, the connecting segment 222 is connected to the side of the second segment 132 facing away from the electrode body 210, and the gathered segment 221 is spaced apart from the second segment 132. It should be understood that by spacing the gathered segment 221 and the second segment 132 apart, the risk of a short circuit caused by accidental contact between the two is avoided. The spacing provides physical isolation, reducing the risk of compression interference between the gathered segment 221 and the connecting piece 130 during bending and deformation, preventing the tab 220 from being squeezed and damaged, reducing the possibility of a short circuit, and enhancing battery safety.

[0063] Connecting the connecting section 222 to the side of the second section 132 facing away from the electrode body 210 helps better utilize the space within the single cell, preventing interference between components and making the internal spatial layout of the battery more compact and orderly. Furthermore, the location of the connecting section 222 on the side of the second section 132 facing away from the electrode body 210 facilitates welding to the second section 132, reducing welding difficulty, improving welding quality and efficiency, and facilitating inspection and replacement during battery maintenance and overhaul, reducing maintenance costs and difficulty.

[0064] See also Figures 1 to 6 As shown, in some embodiments, the cover body 110 is provided with an assembly hole 1100 along the thickness direction X; the pole 120 includes a main body 121, a first connecting portion 122 and a second connecting portion 123, the main body 121 is passed through the assembly hole 1100, the first connecting portion 122 is provided on one side of the cover body 110 along the thickness direction X, and surrounds and connects the main body 121, and the second connecting portion 123 is provided at one end of the main body 121 along the thickness direction X away from the first connecting portion 122. It forms a limiting groove 124 with the main body 121, and the first hole 1200 passes through the main body 121 and the second connecting part 123 along the thickness direction X. On the plane perpendicular to the thickness direction X, the orthographic projection of the limiting groove 124 is located outside the orthographic projection of the first hole 1200; the welding block 150 is arranged on the side of the cover body 110 away from the first connecting part 122, and is partially embedded in the limiting groove 124; the cover body 110 is clamped between the first connecting part 122 and the welding block 150.

[0065] It should be understood that the pole 120 is provided on the cover body 110. Through the assembly connection relationship between the pole 120 and the welding block 150, the cover body 110 is firmly clamped between the first connecting portion 122 and the welding block 150, forming a mechanical clamp in the thickness direction X. The interlocking relationship between the welding block 150 and the limiting groove 124 can further limit the rotational displacement of the pole 120. At the same time, the main body 121 is inserted into the assembly hole 1100 of the cover body 110, limiting the radial displacement of the pole 120. This multiple connection and limiting method effectively enhances the tightness of the connection between the various components, can better resist the stress caused by factors such as thermal expansion and contraction or vibration during the battery charging and discharging process, and ensure the long-term stable operation of the battery in complex environments.

[0066] See also Figures 1 to 6 As shown, in some embodiments, the first connecting portion 122 is disposed on the side of the cover plate body 110 facing the electrode assembly 20, the welding block 150 is disposed on the side of the cover plate body 110 facing away from the electrode assembly 20, and the second connecting portion 123 is riveted outward to form a retaining groove 124, with the opening of the retaining groove 124 facing the outside of the single cell. It should be understood that by arranging the second connecting portion 123 of the terminal 120 and the welding block 150 on the side of the cover plate body 110 facing away from the electrode body 210, and supporting the first connecting portion 122 on the side of the cover plate body 110 facing the electrode assembly 20, a composite structure of internal support and external clamping is adopted to form a mechanical interlock, improving structural stability. This also reduces assembly difficulty, as the alignment of the welding block 150 with the retaining groove 124 is completed in a visible area outside the battery, avoiding obstruction of the internal space. Furthermore, the seal between the welding block 150 and the retaining groove 124 is easier to inspect and maintain.

[0067] It is also necessary to understand that the second section 132 of the connecting piece 130 is located on the side of the first connecting portion 122 facing the electrode body 210, and the second section 132 is spaced apart from the first connecting portion 122. The first connecting portion 122 can serve to separate the second section 132 from the cover body 110 to enhance electrical insulation and reduce the risk of short circuit caused by contact between the connecting piece 130 and the cover body 110.

[0068] See also Figures 10 to 12As shown, in some embodiments, the first connecting portion 122 is disposed on the side of the cover plate body 110 facing away from the electrode assembly 20, the welding block 150 is disposed on the side of the cover plate body 110 facing the electrode assembly 20, and the second connecting portion 123 is riveted away from the first hole 1200 to form a retaining groove 124 (inward riveting). In this case, the opening of the retaining groove 124 is located within the single cell. It should be understood that by arranging the second connecting portion 123 and the welding block 150 on the side of the cover plate body 110 facing the electrode body 210, and supporting the first connecting portion 122 on the side of the cover plate body 110 facing away from the electrode assembly 20, a composite structure of external support and internal locking is used to form a mechanical interlock, enhancing the battery's external impact resistance and improving structural stability. The retaining groove 124 opens inward, shortening the overall dimension of the electrode post 120 along the thickness direction X. The retaining groove 124 formed internally by the inward riveting process does not occupy external space, thereby improving battery space utilization.

[0069] It should also be understood that the second section 132 of the connecting piece 130 is located on the side of the limit block facing the electrode body 210. The limit block can serve to separate the second section 132 from the cover body 110 to enhance electrical insulation and reduce the risk of short circuit caused by contact between the connecting piece 130 and the cover body 110.

[0070] See also Figure 6 、 Figure 12 As shown, in some embodiments, the second connecting portion 123 has a riveted section 125, which is protruded on the side of the second connecting portion 123 away from the first hole 1200; the welding block 150 includes a protrusion 151, which is arranged on the side of the welding block 150 facing the second connecting portion 123, and the protrusion 151 is embedded in the limiting groove 124; in the thickness direction X, the protrusion 151 abuts against the riveted section 125.

[0071] It should be understood that by riveting the second connecting portion 123 in a direction away from the first hole 1200 to form a riveted section 125, the riveted section 125 is used to connect and limit the welding block 150 to ensure that the welding block 150 and the first connecting portion 122 can firmly clamp the cover body 110. The welding block 150 is partially embedded in the limiting groove 124, which increases the connection area and connection strength between the welding block 150 and the pole 120, effectively avoiding loose connections due to thermal expansion and contraction or mechanical vibration during battery charging and discharging, improving the reliability of the internal connection of the battery, and thus improving the overall performance and service life of the battery.

[0072] It should be understood that the riveting of the riveted segments 125 and the protrusions 151 increases the contact area and mechanical strength of the connection, forming a tight connection between the riveted segments 125 and the protrusions 151 and distributing stress, preventing loosening or falling of the connection, thereby safeguarding the integrity of the battery's internal structure and maintaining stable battery performance. During assembly, the riveted segments 125 provide clear positioning and guidance for the welding block 150, reducing assembly difficulty and improving assembly efficiency.

[0073] It should also be understood that the pole 120 of the present application can be completed in a single process during the manufacturing process, eliminating the need for complex secondary machining processes, greatly improving production efficiency and reducing processing costs. The structural design of the pole 120 facilitates the assembly of the various components. The main body 121 of the pole 120 is provided with an assembly hole 1100, and the welding block 150 is directly embedded in the retaining groove 124, thereby achieving a stable connection between the pole 120 and the cover body 110. This reduces complex assembly steps and additional fixing components, improves production efficiency, reduces production costs, and facilitates large-scale production.

[0074] See also Figure 6 and cooperate with Figure 13 As shown, in some embodiments, the protrusion 151 has a first surface 152, which is located on the side of the protrusion 151 facing away from the main body 121. The limiting groove 124 has a second surface 126, which is arranged opposite to the first surface 152. The cover plate assembly 10 also includes a second welding portion 160, which connects the first surface 152 and the second surface 126. It should be understood that the second welding portion 160 connects the protrusion 151 and the riveted section 125, and the abutment between the protrusion 151 and the riveted section 125 makes the connection between the protrusion 151 and the riveted section 125 tighter. At the same time, the second welding portion 160 can fill the assembly gap between the protrusion 151 and the riveted section 125, thereby reducing the risk of electrolyte leakage or external contamination entering the interior of the battery.

[0075] The present application also discloses a battery pack including the single cell battery of the above embodiment. Therefore, the battery pack can have all the technical features and effects of the single cell battery, which will not be described in detail here.

[0076] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] The above is a detailed introduction to the single cell and battery pack provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single battery, characterized in that: include: A cover plate assembly (10) and an electrode assembly (20), wherein the electrode assembly (20) is arranged on one side of the cover plate assembly (10) in the thickness direction (X) thereof, the electrode assembly (20) comprises an electrode body (210) and a pole lug (220) connected to each other, the cover plate assembly (10) comprises a cover plate body (110) and a pole (120), the pole (120) is arranged on the cover plate body (110), and the pole (120) is provided with a through first hole (1200) along the thickness direction (X); The single cell battery further comprises a connecting piece (130), the connecting piece (130) comprising a first section (131) and a second section (132), the first section (131) being passed through the first hole (1200) and connected to the pole (120), the first section (131) covering the first hole (1200), and the second section (132) being arranged on a side of the cover plate body (110) facing the electrode body (210), and respectively connecting the first section (131) and the pole lug (220).

2. The single cell according to claim 1, characterized in that: The first section (131) includes a first wall (1311) and a plurality of second walls (1312), wherein the first wall (1311) is connected to the pole (120) and covers the first hole (1200), and the plurality of second walls (1312) are circumferentially arranged and connected to the side of the first wall (1311) facing the electrode assembly (20), the first wall (1311) and the plurality of second walls (1312) form a main body groove (1300), and the second wall (1312) is connected to the second section (132) at an end away from the first wall (1311).

3. The single cell according to claim 2, characterized in that: The cover plate assembly (10) further comprises a first welding portion (140), wherein the first welding portion (140) connects the inner wall of the first hole (1200) and the first wall (1311); And / or, the first welding portion (140) connects the inner wall of the first hole (1200) and the plurality of second walls (1312).

4. The single cell according to claim 2 or 3, characterized in that: The first wall (1311) has a wall thickness dimension of d1 mm, the second wall (1312) has a wall thickness dimension of d2 mm, and the second section (132) has a wall thickness dimension of d3 mm, satisfying: 1.5≤d1≤3.2, 1.2≤d2≤2.0, 0.45≤d3≤1.

2.

5. The single cell according to claim 1, characterized in that: The electrode tab (220) includes a folded section (221) and a connecting section (222), wherein the folded section (221) is connected to the electrode body (210), and the connecting section (222) is connected to the second section (132). The folded section (221) is connected to the connecting section (222) at an end away from the electrode body (210).

6. The single cell according to claim 5, characterized in that: The connecting section (222) is connected to a side of the second section (132) facing away from the electrode body (210), and the retracting section (221) is spaced apart from the second section (132).

7. The single cell according to claim 1, characterized in that: The cover plate body (110) is provided with an assembly hole (1100) along the thickness direction (X); The pole (120) comprises a main body (121), a first connecting portion (122) and a second connecting portion (123); the main body (121) is inserted into the assembly hole (1100); the first connecting portion (122) is arranged on one side of the cover body (110) along the thickness direction (X) and surrounds and connects the main body (121); the second connecting portion (123) is arranged at one end of the main body (121) away from the first connecting portion (122) along the thickness direction (X) and forms a limiting groove (124) with the main body (121); the first hole (1200) passes through the main body (121) and the second connecting portion (123) along the thickness direction (X); on a plane perpendicular to the thickness direction (X), the orthographic projection of the limiting groove (124) is located outside the orthographic projection of the first hole (1200); a welding block (150) disposed on a side of the cover plate body (110) facing away from the first connecting portion (122) and partially embedded in the limiting groove (124); The cover plate body (110) is sandwiched between the first connecting portion (122) and the welding block (150).

8. The single cell according to claim 7, characterized in that: The second connecting portion (123) has a riveted section (125), and the riveted section (125) is protrudingly provided on a side of the second connecting portion (123) away from the first hole (1200); The welding block (150) comprises a convex portion (151), the convex portion (151) is arranged on a side of the welding block (150) facing the second connecting portion (123), and the convex portion (151) is embedded in the limiting groove (124); In the thickness direction (X), the convex portion (151) abuts against the riveting section (125).

9. The single cell according to claim 8, characterized in that: The convex portion (151) has a first surface (152), the first surface (152) is located on a side of the convex portion (151) away from the main body (121), and the limiting groove (124) has a second surface (126), and the second surface (126) is arranged opposite to the first surface (152); The cover plate assembly (10) further includes a second welding portion (160), wherein the second welding portion (160) connects the first surface (152) and the second surface (126).

10. A battery pack, characterized in that: The method comprises the single cell according to any one of claims 1 to 9.

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