Single battery

Abstract

The single battery comprises a first conductive part, a second conductive part, an isolation ring and a battery cell assembly, specifically, the first conductive part comprises a working surface and an appearance surface which are oppositely arranged, a conductive hole is formed in the first conductive part, the conductive hole penetrates through the working surface and the appearance surface, and the working surface faces the interior of the single battery; the second conductive part comprises a riveting column, and a riveting seat and a riveting buckle connected to two ends of the riveting column, the riveting column penetrates through the conductive hole, and the riveting buckle is riveted on the appearance surface; the isolating ring is sleeved on the riveting column, and is clamped between the riveting seat and the working surface; and the battery core assembly is welded with the second conductive piece. The first conductive part and the second conductive part are separated by the isolation ring, so that the first conductive part and the second conductive part are not easy to be subjected to electrochemical corrosion even if being soaked in electrolyte.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a single battery. Background Art

[0002] In order to improve the welding performance of the busbar and the single cell housing, an effective improvement method is to embed a terminal made of the same material as the busbar on the cover of the single cell, so that the terminal and the busbar can be welded homogeneously. In the above technical solution, because the terminal and the cover are made of dissimilar metals, and the inside of the single cell is often filled with electrolyte, obvious electrochemical corrosion will occur between the cover and the terminal, which not only affects the current carrying capacity of the first conductive member and the second conductive member, but also destroys the airtightness of the single cell housing. Summary of the invention

[0003] An object of the present invention is to provide a single cell, which aims to solve the technical problem that parameters are difficult to match and welding effect is poor when the shell and the busbar are welded together.

[0004] To achieve the above-mentioned purpose, the present invention provides a solution: a single battery, which includes a first conductive member, a second conductive member, an isolation ring and a battery cell assembly. Specifically, the first conductive member includes a working surface and an appearance surface that are arranged opposite to each other, and an electrical conduction hole is opened on the first conductive member, and the electrical conduction hole passes through the working surface and the appearance surface, and the working surface faces the interior of the single battery; the second conductive member includes a rivet column and a rivet seat and a rivet buckle connected to both ends of the rivet column, the rivet column is penetrated by the conductive hole, and the rivet buckle is riveted to the appearance surface; the isolation ring is sleeved on the rivet column, and the rivet seat and the working surface are sandwiched by the isolation ring; the battery cell assembly is welded and connected to the second conductive member.

[0005] In some embodiments of the present application, a welding hole is further formed on the second conductive member, and an opening direction of the welding hole is toward a side of the second conductive member away from the battery cell assembly.

[0006] In some embodiments of the present application, the diameter of the conductive hole is D1, the diameter of the welding hole is D2, and 30%≤D2 / D1≤90%.

[0007] In some embodiments of the present application, the depth of the welding hole is L1, the projection length of the second conductive member in the thickness direction of the first conductive member is L2, and 50%≤L1 / L2≤90%.

[0008] In some embodiments of the present application, the minimum distance between the hole wall of the welding hole and the outer wall of the second conductive member is L3, and L3 is ≥ 0.05 mm.

[0009] In some embodiments of the present application, the distance between the bottom of the welding hole and the surface of the second conductive member on one side close to the battery cell assembly is L4, and 0.05mm≤L4≤2mm.

[0010] In some embodiments of the present application, the battery cell assembly includes a battery cell and a busbar, and the busbar is electrically connected to the battery cell and the second conductive member, respectively.

[0011] In some embodiments of the present application, the area of ​​the working surface is S1, the projected area of ​​the contact surface between the second conductive member and the busbar on the working surface is S2, and 20%≤S2 / S1≤90%.

[0012] In some embodiments of the present application, the second conductive element is connected to the busbar through a first weld, the projection area of ​​the first weld on the busbar surface is S3, the surface area of ​​the busbar close to the first conductive element structure is S4, and S3 / S4≥10%.

[0013] In some embodiments of the present application, the second conductive member is welded to a side of the busbar close to the first conductive member, and a side of the busbar away from the second conductive member is electrically connected to the battery cell.

[0014] In some embodiments of the present application, the second conductive member and the busbar are made of the same material.

[0015] In some embodiments of the present application, the battery cell assembly includes a winding core and a pole tab that are electrically connected, and the pole tab is welded to the second conductive member.

[0016] In some embodiments of the present application, the second conductive member and the tab are made of the same material.

[0017] In some embodiments of the present application, there are multiple conductive holes, and the second conductive members are arranged corresponding to the conductive holes one by one.

[0018] In some embodiments of the present application, a plurality of electrical conductive holes are arranged in a circular array on the first conductive member.

[0019] In some embodiments of the present application, the material of the second conductive member includes copper.

[0020] In some embodiments of the present application, the single cell further includes a first isolation layer, the first isolation layer wraps the second conductive member, and the rivet seat is at least partially exposed.

[0021] In some embodiments of the present application, the material of the first isolation layer includes at least one of steel and nickel.

[0022] In some embodiments of the present application, the area of ​​the exposed portion of the rivet seat is S5, the area of ​​the first conductive member close to the battery cell assembly is S1, and 40%≤S5 / S1≤100%.

[0023] In some embodiments of the present application, the diameter of the rivet seat is D4, the outer diameter of the isolation ring is D5, and 70%≤D4 / D5≤120%.

[0024] In some embodiments of the present application, the thickness of the isolation ring is L9, 0.5≤L9≤1.5mm.

[0025] In some embodiments of the present application, an outer edge of one end of the rivet button away from the rivet seat is provided with an outer chamfer, and on any cross section passing through the axis of the rivet button, an angle between the outer chamfer and the appearance surface is A1, 10°≤A1≤85°.

[0026] In some embodiments of the present application, the distance between the outer edge of the outer chamfer and the appearance surface is L5, the thickness of the rivet is L6, and 0≤L5 / L6≤70%.

[0027] In some embodiments of the present application, the thickness of the rivet is L6, the projection length of the second conductive member in the thickness direction of the rivet is L7, and 10%≤L6 / L7≤40%.

[0028] In some embodiments of the present application, the diameter of the conductive hole is D1, the outer diameter of the rivet is D3, and 120%≤D3 / D1≤200%.

[0029] In some embodiments of the present application, the diameter of the rivet seat is D4, 2mm≤D4≤20mm.

[0030] In some embodiments of the present application, the diameter of the conductive hole is D1, the diameter of the rivet seat is D4, and 130%≤D4 / D1≤200%.

[0031] In some embodiments of the present application, the thickness of the rivet seat is L8, 0.05mm≤L8≤2mm.

[0032] In some embodiments of the present application, a rivet hole is further formed on the second conductive member, and an opening direction of the rivet hole is toward a side of the second conductive member away from the battery cell assembly.

[0033] In some embodiments of the present application, the edge of the riveting hole is provided with an inner chamfer, and on any cross section passing through the axis of the riveting hole, the angle between the inner chamfer plane and the appearance surface is A2, 30°≤A2≤85°.

[0034] In some embodiments of the present application, the diameter of the riveting hole is D6, the minimum outer diameter of the second conductive member is D7, and 30%≤D6 / D7≤80%.

[0035] In some embodiments of the present application, the first conductive member is further formed with a pressure relief groove, and the pressure relief groove is recessed on the surface of the first conductive member to avoid the electrical conductive hole.

[0036] In some embodiments of the present application, the distance between the edge of the pressure relief groove and the edge of the conductive hole is L10, 2mm<L10<35mm.

[0037] In some embodiments of the present application, the maximum width of the pressure relief groove is L11, 0.05mm≤L11≤5mm.

[0038] In some embodiments of the present application, the pressure relief groove is opened on the exterior surface.

[0039] In some embodiments of the present application, the distance between the bottom of the pressure relief groove and the working surface is L12, 0.02mm≤L12≤1.5mm.

[0040] In some embodiments of the present application, the angle between the pressure relief groove and the two groove walls is A3, 20°≤A3≤90°.

[0041] In some embodiments of the present application, the cross-section of the pressure relief groove perpendicular to its extension direction is a trapezoid, and the lower base of the trapezoid is located on the surface of the first conductive member.

[0042] In some embodiments of the present application, the length of the upper base of the trapezoid is L13, 0.02mm≤L13≤3mm.

[0043] In some embodiments of the present application, the bottom of the pressure relief groove has rounded corners.

[0044] In some embodiments of the present application, the radius of the fillet is R1, the maximum width of the pressure relief groove is L11, and 20%≤R1 / L11≤100%.

[0045] In some embodiments of the present application, the single cell further includes a second isolation layer, and the second isolation layer covers a surface of the first conductive member facing the battery cell assembly.

[0046] In some embodiments of the present application, the second isolation layer is a nickel plating layer or an iron alloy plating layer.

[0047] In some embodiments of the present application, the second isolation layer is one of a PP film and a PPS.

[0048] In some embodiments of the present application, the area of ​​the first conductive member close to the battery cell assembly is S1, the projection area of ​​the second isolation layer on the surface of the first conductive member is S8, and 5%≤S8 / S1≤97%.

[0049] In some embodiments of the present application, the thickness of the second isolation layer is L14, 0.05 mm ≤ L14 ≤ 2 mm.

[0050] In some embodiments of the present application, the thickness of the second isolation layer is evenly distributed on the entire surface of the first conductive member.

[0051] In some embodiments of the present application, the thickness of the second isolation layer increases as it approaches the conductive hole.

[0052] In some embodiments of the present application, the single cell battery further includes a shell, one side of the shell is open, the first conductive member blocks the opening of the shell and together with the shell forms an accommodating space, and the battery cell assembly is disposed in the accommodating space.

[0053] In some embodiments of the present application, the single cell further includes a second weld, and the first conductive member and the cover plate are connected via the second weld.

[0054] In some embodiments of the present application, the height of the second weld protruding from the shell surface is H3, 0mm≤H3≤3mm.

[0055] In some embodiments of the present application, the width of the second weld is L15, 2mm≤L15≤6mm.

[0056] In some embodiments of the present application, the first conductive member includes a first plate, a second plate and a third plate, the conductive hole is opened in the first plate, the third plate is wrapped around the first plate, the shell is connected to the third plate, the opposite ends of the second plate are respectively connected to the first plate and the third plate, and the first plate and the second plate are embedded in the opening of the shell.

[0057] In some embodiments of the present application, the first plate and the second plate are connected by an arc.

[0058] In some embodiments of the present application, the radius of the arc is R2, 0.1mm≤R2≤2mm.

[0059] In some embodiments of the present application, the radius of the arc is R2, the thickness of the first plate is L16, and 20%≤R2 / L16≤100%.

[0060] In some embodiments of the present application, there is an assembly gap between the second plate and the housing.

[0061] In some embodiments of the present application, the width of the assembly gap is L17, 0.1 mm ≤ L17 ≤ 0.5 mm.

[0062] The beneficial effects of the present invention are:

[0063] A sealing ring is sandwiched between the rivet seat of the second conductive member and the working surface of the first conductive member, so that there is no direct contact between the first conductive member and the second conductive member exposed to the electrolyte environment, so that there is no condition for electrochemical corrosion to occur between the two. At this time, the first conductive member and the second conductive member can be selected to be made of different materials, so that the welding of the second conductive member and the busbar of the battery cell assembly is homogeneous welding, and the weld quality is better, and the service life of the single battery will not be affected by electrochemical corrosion between the first conductive member and the second conductive member. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0065] Figure 1 is a schematic diagram of the overall structure of a single cell provided by an embodiment of the present invention;

[0066] Figure 2 is an overall cross-sectional view of a single cell provided by an embodiment of the present invention;

[0067] Figure 3 yes Figure 2 A partial enlarged view of the middle A area;

[0068] Figure 4 is a schematic diagram of the coordination of a second conductive member and a battery cell assembly provided by another embodiment of the present invention;

[0069] Figure 5 is a schematic diagram of the coordination of the second conductive member and the first isolation layer provided by an embodiment of the present invention;

[0070] Figure 6 is a schematic diagram of the coordination of the first conductive member, the second conductive member and the isolation ring provided by an embodiment of the present invention;

[0071] Figure 7 is a schematic diagram of the coordination of the first conductive member, the second conductive member and the isolation ring provided in an embodiment of the present invention;

[0072] Figure 8 yes Figure 2 A partial enlarged view of the middle B area;

[0073] Fig. 9 is a schematic diagram of the coordination between the pressure relief groove and the second conductive member provided by another embodiment of the present invention;

[0074] Fig.10 is a schematic diagram of the coordination between the pressure relief groove and the second conductive member provided by another embodiment of the present invention;

[0075] Fig.11 is a schematic diagram of the coordination of a first conductive member, a second conductive member, an isolation ring, and a second isolation layer provided by an embodiment of the present invention;

[0076] Fig.12 is a schematic diagram of the coordination of a first conductive member, a second conductive member, an isolation ring, and a second isolation layer provided by another embodiment of the present invention;

[0077] Fig.13It is a schematic diagram of the connection relationship between the first conductive member and the shell provided in an embodiment of the present invention.

[0078] Description of Figure Numbers:

[0079] 10. First conductive member; 11. Conductive hole; 12. Pressure relief groove; 13. First plate; 14. Second plate; 15. Third plate; 20. Second conductive member; 21. Welding hole; 22. Rivet column; 23. Rivet seat; 24. Rivet buckle; 241. External chamfer; 242. Riveted hole; 243. Internal chamfer; 30. Battery cell assembly; 31. Battery cell; 311. Winding core; 312. Tab; 32. Busbar; 41. First weld; 42. Second weld; 51. First isolation layer; 52. Second isolation layer; 60. Isolation ring; 70. Shell; 80. Assembly gap. DETAILED DESCRIPTION

[0080] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0081] In order to solve the electrochemical corrosion problem in a single cell, an embodiment of the present invention provides a single cell. The single cell includes a first conductive member 10 , a second conductive member 20 , an isolation ring 60 and a cell assembly 30 .

[0082] See also Figures 1 to 3 As shown, Figure 1 is a schematic diagram of the overall structure of a single cell provided by an embodiment of the present invention; Figure 2 is an overall cross-sectional view of a single cell provided by an embodiment of the present invention; Figure 3 yes Figure 2 The above figures together show the matching relationship among the first conductive member 10 , the second conductive member 20 and the battery cell 31 .

[0083] Specifically, the first conductive member 10 includes a working surface and an appearance surface that are relatively arranged, the working surface faces the interior of the single battery, and an electrical conduction hole 11 is opened on the first conductive member 10, and the electrical conduction hole 11 passes through the working surface and the appearance surface, and the thickness direction of the first conductive member 10 passes through the first conductive member 10; the second conductive member 20 includes a rivet column 22 and a rivet seat 23 and a rivet buckle 24 connected to both ends of the rivet column 22, the rivet column 22 passes through the electrical conduction hole 11, and the rivet buckle 24 is riveted to the appearance surface; the isolation ring 60 is sleeved on the rivet column 22, and the rivet seat 23 and the working surface clamp the isolation ring 60; the battery cell assembly 30 is welded and connected to the second conductive member 20.

[0084] The first conductive member 10 and the second conductive member 20 are designed separately, and the two can be configured with different materials according to needs. Exemplarily, the second conductive member 20 is configured with the same material as the area of ​​the battery cell assembly 30 to which it is welded, so as to optimize the weld performance between the second conductive member 20 and the battery cell assembly 30. However, the interior of the single cell is often filled with electrolyte, and the joint of the first conductive member 10 and the second conductive member 20 is immersed in the electrolyte, which will cause more serious electrochemical corrosion, resulting in a gap between the first conductive member 10 and the second conductive member 20, which not only affects the current carrying capacity of the first conductive member 10 and the second conductive member 20, but also destroys the airtightness of the single cell shell.

[0085] Compared with the prior art, an isolation ring 60 is sandwiched between the rivet seat 23 of the second conductive member 20 and the working surface of the first conductive member 10 in this embodiment, so that the first conductive member 10 and the second conductive member 20 made of dissimilar metal materials are separated, the corrosion rate is slowed down, and the working life of the single battery is extended.

[0086] The rivet seat 23 abuts against the working surface, and the rivet button 24 abuts against the appearance surface. The formation of the rivet button 24 depends on the deformation caused by the riveting machine stamping. The length of the rivet column 22 depends on the deformation of the rivet button 24 during the riveting process. Therefore, the rivet column 22 can adapt to the thickness of the first conductive member 10 and the isolation ring 60, so that the rivet seat 23 and the rivet button 24 can better clamp the first conductive member 10 and the isolation ring 60. The slight deformation of the isolation ring 60 after being clamped can also better seal the gap between the first conductive member 10 and the second conductive member 20, thereby enhancing the airtightness of the single battery.

[0087] In some embodiments of the present application, a welding hole 21 is further formed on the second conductive member 20 , and the opening direction of the welding hole 21 is toward a side of the second conductive member 20 away from the battery cell assembly 30 .

[0088] For the sake of clarity, the processing steps of a single cell are explained here. Normally, during the processing of a single cell, in order to achieve welding between the outer shell and the battery cell assembly 30, the conductive area of ​​the battery cell assembly 30 is abutted against the outer shell from the inside of the outer shell, and then the welding gun is aimed at the corresponding area on the outside of the outer shell, and the conductive area of ​​the battery cell assembly 30 and the abutting area of ​​the outer shell are melted through the outer shell by applying voltage and high temperature, and a weld is formed after the molten metal solidifies.

[0089] Because the above welding process needs to be melted across the outer shell, the thickness of the outer shell determines the power requirement and weld penetration of the welding. In this embodiment, the second conductive member 20 is welded to the battery cell assembly 30. Therefore, the smaller the distance between the outer surface and the inner surface of the welding area of ​​the second conductive member 20, the easier it is to weld. Providing a welding hole 21 on the second conductive member 20 allows the welding gun to be closer to the area where the battery cell assembly 30 and the second conductive member 20 are connected. On the one hand, this reduces the loss during energy transmission, and on the other hand, it also avoids overburning of the second conductive member 20 during welding, effectively ensuring that the second conductive member 20 still retains good electrical and mechanical properties after welding.

[0090] Furthermore, the diameter of the conductive hole 11 is D1, the diameter of the welding hole 21 is D2, and 30%≤D2 / D1≤90%.

[0091] The diameter of the welding hole 21 is limited by the diameter of the conductive hole 11. A larger welding hole 21 allows a larger welding gun to be inserted into the welding hole 21 for welding. However, when the size of the conductive hole 11 is determined, an overly large welding hole 21 will make the wall thickness of the second conductive member 20 where the welding hole 21 is opened too thin, affecting the strength and current carrying capacity of the second conductive member 20. The selection of the value of 30%≤D2 / D1≤90% can make the welding hole 21 as easy as possible for the welding gun to be inserted while ensuring the strength and current carrying capacity of the second conductive member 20.

[0092] Optionally, the depth of the welding hole 21 is L1, the projection length of the second conductive member 20 in the thickness direction of the first conductive member 10 is L2, and 50%≤L1 / L2≤90%.

[0093] The depth of the welding hole 21 is limited by the second conductive member 20. A too shallow welding hole 21 requires the welding current or heat energy to penetrate the thicker bottom of the second conductive member 20, which wastes energy and destroys the crystal structure of the second conductive member 20. A too deep welding hole 21 makes the bottom of the second conductive member 20 too thin, which may cause the risk of overheating or even burning through during welding. The value selection of 50%≤L1 / L2≤90% can make the thickness of the bottom of the second conductive member 20 suitable for the welding process.

[0094] It should be noted that the thickness direction mentioned in this embodiment does not mean that the size of the first conductive member 10 in this direction must be smaller than its diameter. The description here only represents that in most existing single cells, the thickness direction is the direction in which the first conductive member 10 is buckled with the housing 70. All the size descriptions involved below are only general descriptions of the technical field without additional restrictions, and do not mean that there are no special cases. The specific references should be based on the marks in the corresponding drawings.

[0095] Optionally, the minimum distance between the hole wall of the welding hole 21 and the outer wall of the second conductive member 20 is L3, and L3 is ≥ 0.05 mm.

[0096] The welding hole 21 is preferably coaxially arranged with the second conductive part 20, but considering the processing accuracy and assembly concessions, there are also application scenarios in which the two are eccentrically arranged. Limiting L3 ≥ 0.05 mm can effectively prevent the distance between the hole wall of the welding hole 21 and the outer wall of the second conductive part 20 from being too close, thereby avoiding breakdown of the second conductive part 20 due to insufficient current carrying capacity during the subsequent use of the single cell.

[0097] Optionally, the distance between the bottom of the welding hole 21 and the surface of the second conductive member 20 on one side close to the battery cell assembly 30 is L4, and 0.05 mm ≤ L4 ≤ 2 mm.

[0098] The size of the second conductive member 20 changes with the capacity and design of the single battery, but the bottom thickness of the second conductive member 20 that carries the welding current and heat, that is, the distance between the bottom of the welding hole 21 and the surface of the second conductive member 20 close to the battery cell assembly 30, is limited by the welding process and has a specific range of parameters, which will not be significantly changed by the change of the second conductive member 20. Calculations show that the value range of 0.05mm≤L4≤2mm can prevent the bottom of the second conductive member 20 that is too thin from being burned through, and can also prevent energy waste caused by an overly thick bottom, which is a better parameter configuration.

[0099] In some embodiments of the present application, the battery cell assembly 30 includes a battery cell 31 and a busbar 32 , and the busbar 32 is electrically connected to the battery cell 31 and the second conductive member 20 , respectively.

[0100] The busbar 32 can collect the current of the entire battery cell 31. The second conductive member 20 and the busbar 32 are welded, and the current of the battery cell 31 is conducted to the first conductive member 10 via the busbar 32 and the second conductive member 20. During the entire current transmission process, the original largest resistance segment is greatly optimized because the second conductive member 20 and the busbar 32 are welded, thereby improving the energy efficiency of the single battery.

[0101] Furthermore, the area of ​​the working surface is S1, the projected area of ​​the contact surface between the second conductive member 20 and the busbar 32 on the working surface is S2, and 20%≤S2 / S1≤90%.

[0102] The larger the contact area between the second conductive member 20 and the busbar 32, the stronger the flow conductivity between the two. However, this positive correlation has a limit due to the area of ​​the busbar 32. 20% ≤ S2 / S1 ≤ 90% is a numerical range that can obtain more intuitive performance optimization from the increase in the area of ​​the busbar 32 and the second conductive member 20.

[0103] It should be noted that the projection area here refers to the area of ​​the largest figure that can be enclosed by the projection of the structure on the corresponding plane. For structures with holes inside, the projection area should be enclosed by the outer edge of the projection figure.

[0104] Optionally, the second conductive member 20 is connected to the busbar 32 via a first weld 41, a projection area of ​​the first weld 41 on the surface of the busbar 32 is S3, a surface area of ​​the busbar 32 close to the first conductive member 10 is S4, and S3 / S4 ≥ 10%.

[0105] The larger the proportion of the first weld 41, the more stable the connection between the busbar 32 and the second conductive member 20. In particular, in the technical solution that requires stabilizing the position of the battery cell assembly 30 by the first weld 41, the cross-sectional area of ​​the first weld 41 is directly related to whether the battery cell assembly 30 can maintain the connection with the second conductive member 20. S3 / S4≥10% is the preferred numerical range for maintaining the connection between the second conductive member 20 and the busbar 32.

[0106] Optionally, the second conductive member 20 is welded to a side of the busbar 32 close to the first conductive member 10 , and a side of the busbar 32 away from the second conductive member 20 is electrically connected to the battery cell 31 .

[0107] The two sides of the busbar 32 are electrically connected to the second conductive member 20 and the battery cell 31 respectively, so that the surface area of ​​the busbar 32 can be fully utilized as much as possible to increase the flow area and current carrying capacity.

[0108] Optionally, the second conductive member 20 and the busbar 32 are made of the same material.

[0109] The second conductive member 20 and the busbar 32 made of the same material have similar welding parameters and fluidity, and the effect of homogeneous welding is better.

[0110] Please also read Figure 4 As shown, Figure 4 It is a schematic diagram of the coordination between the second conductive member 20 and the battery cell assembly 30 provided in another embodiment of the present invention.

[0111] In some embodiments of the present application, the battery cell assembly 30 includes a winding core 311 and a tab 312 that are electrically connected, and the tab 312 is welded to the second conductive member 20 .

[0112] This embodiment provides another technical solution. In the technical solution in which the busbar 32 is not provided, the second conductive member 20 can also be directly electrically connected to the battery cell 31. Specifically, the battery cell 31 includes a winding core 311 and a pole tab 312, and the second conductive member 20 and the pole tab 312 are welded and connected.

[0113] Furthermore, the second conductive member 20 and the tab 312 are made of the same material.

[0114] Similar to the busbar 32 , the second conductive member 20 and the tab 312 made of the same material have similar welding parameters and fluidity, and the effect of homogeneous welding is better.

[0115] In some embodiments of the present application, there are multiple conductive holes 11 , and the second conductive members 20 are disposed corresponding to the conductive holes 11 one by one.

[0116] The plurality of conductive holes 11 can disperse the current-carrying area, thereby achieving a better current-carrying effect while keeping the total flow area unchanged.

[0117] Furthermore, a plurality of conductive holes 11 are arranged in a circumferential array on the first conductive member 10 .

[0118] On the one hand, the conductive holes 11 formed in a circumferential array can make the current distribution more uniform and optimize the electrical performance of the single cell. On the other hand, the conductive holes 11 formed in a circumferential array can also minimize the damage to the mechanical performance of the single cell caused by opening holes in the first conductive member 10.

[0119] In some embodiments of the present application, the material of the second conductive member 20 includes copper.

[0120] The existing battery cell assembly 30, whether it is the type that outputs directly to the outside through the pole ear 312 or the type that outputs after convergence through the busbar 32, the material of the output end is mostly made of copper. The material of the second conductive member 20 includes copper, which can enhance the welding matching degree between the second conductive member 20 and the battery cell assembly 30, simplify the welding process, and optimize the weld performance.

[0121] It should be noted that in this embodiment, the busbar 32 and the pole lug 312 are described as output ends. In a considerable number of battery cell assemblies 30, the busbar 32 and the pole lug 312 both assume the function of current input. The description here only expresses that during the use of the single battery, the busbar 32 and the pole lug 312 assume the output function, and does not limit them to only output. The protection scope of this application cannot be limited to this. The output of the following embodiments is also understood in this way.

[0122] Please also read Figure 5 As shown, Figure 5 It is a schematic diagram of the coordination of the second conductive member 20 and the first isolation layer 50 provided in an embodiment of the present invention.

[0123] Furthermore, the single battery cell further includes a first isolation layer 51 , which wraps the second conductive member 20 , and a side of the second conductive member 20 close to the battery cell assembly 30 is at least partially exposed.

[0124] In the actual processing, the second conductive member 20 and the battery cell assembly 30 are only welded at the abutting part. Therefore, when the welding area is exposed, setting the first isolation layer 51 to protect other areas of the second conductive member 20 is an effective method to extend the service life of the second conductive member 20. In the actual operation of the single battery, because the first conductive member 10 and the second conductive member 20 are dissimilar metals, the connection area between the two immersed in the electrolyte will produce a certain amount of electrochemical corrosion. Using the first isolation layer 51 to isolate the first conductive member 10 and the second conductive member 20 can effectively reduce the corrosion rate of the joint between the two.

[0125] Furthermore, the material of the first isolation layer 51 includes at least one of steel and nickel.

[0126] On the one hand, steel and nickel are also commonly used materials for the first conductive member 10. Therefore, electrochemical corrosion is unlikely to occur between the first insulating layer 51 and the first conductive member 10 that are in direct contact. On the other hand, the joint between the first insulating layer 51 and the second conductive member 20 is closed between the second conductive member 20 and the battery cell assembly 30. It is difficult for the electrolyte to enter, and there is no environment for electrochemical corrosion. Therefore, electrochemical corrosion is unlikely to occur.

[0127] Optionally, the area of ​​the exposed portion of the second conductive member 20 close to the battery cell assembly 30 is S5, the area of ​​the first conductive member 10 close to the battery cell assembly 30 is S1, and 40%≤S5 / S1≤100%.

[0128] Sufficient exposed area of ​​the second conductive member 20 is a prerequisite for ensuring good weldability and current carrying capacity between the second conductive member 20 and the battery cell assembly 30. When S5 / S1 is less than 40%, the welding effect will be significantly affected. The preferred value of S5 / S1 is 70% or 80%.

[0129] Please also read Figure 6 and Figure 7 As shown, Figure 6 1 is a schematic diagram of the coordination of the first conductive member 10, the second conductive member 20 and the isolation ring 60 provided in an embodiment of the present invention; Figure 7 It is a schematic diagram of the coordination of the first conductive member 10, the second conductive member 20 and the isolation ring 60 provided in an embodiment of the present invention.

[0130] In some embodiments of the present application, an outer edge of one end of the rivet button 24 away from the rivet seat 23 is provided with an outer chamfer 241. On any cross section passing through the axis of the rivet button 24, the included angle between the outer chamfer 241 and the appearance surface is A1, 10°≤A1≤85°.

[0131] The setting of the outer chamfer 241 can effectively prevent the rivet 24 from being scratched and damaged by other parts. An excessively large A1 will lead to the formation of new ridges, making the outer chamfer 241 meaningless, while an excessively small A1 will lead to the rivet 24 extending a long distance outward to absorb the thickness of the rivet 24. The selection of a value of 10°≤A1≤85° is conducive to structural design and can also be adapted to existing riveting machines. The preferred value of A1 is 45°, 48° or 54°.

[0132] Specifically, the distance between the outer edge of the outer chamfer 241 and the appearance surface is L5, the thickness of the rivet button 24 is L6, and 0≤L5 / L6≤70%.

[0133] If the distance between the outer edge of the outer chamfer 241 and the appearance surface is too great, it will affect the appearance of the single battery and increase the risk of damage caused by collision of the single batteries in the battery pack. 0≤L5 / L6≤70% is a better numerical choice, and L5 / L6 is most preferably 0%, that is, the outer edge of the outer chamfer 241 directly fits the surface of the first conductive component 10.

[0134] Optionally, the thickness of the rivet buckle 24 is L6, the projection length of the second conductive member 20 in the thickness direction of the rivet buckle 24 is L7, and 10%≤L6 / L7≤40%.

[0135] Although the thickness of the rivet button 24 will change due to the thickness of the material it rivets, the thickness of the rivet button 24 itself still has a certain reference value. A too small size of the rivet button 24 may cause the rivet button 24 to fall off the rivet column 22, resulting in failure of the connection between the first conductive member 10 and the second conductive member 20. A too large size of the rivet button 24 indicates that there is a defect in the selection of the riveting size, resulting in a large waste of materials and an increase in the redundant weight of the single battery. 10%≤L6 / L7≤40% can ensure the connection effect of the first conductive member 10 and the second conductive member 20 while saving materials as much as possible. The preferred values ​​of L6 / L7 are 20%, 23%, and 25%.

[0136] Optionally, the diameter of the conductive hole 11 is D1, the outer diameter of the rivet button 24 is D3, and 120%≤D3 / D1≤200%.

[0137] The outer diameter of the rivet buckle 24 determines the riveting strength. Under the premise that the size of the conductive hole 11 is fixed, the larger the outer diameter of the rivet buckle 24, the better the riveting effect. Correspondingly, an oversized rivet buckle 24 will cause space occupation and material waste. 120% ≤ D3 / D1 ≤ 200% is a choice to save materials as much as possible while ensuring the riveting strength. Under the premise that the processing accuracy allows, D3 / D1 is preferably 128% or 130%.

[0138] Optionally, the diameter of the rivet seat 23 is D4, 2mm≤D4≤20mm.

[0139] The diameter of the rivet seat 23 determines the pressure bearing capacity of the second conductive member 20 during the riveting process, which is not affected by the conductive hole 11. An oversized rivet seat 23 will undoubtedly occupy extra space. Therefore, 2mm≤D4≤20mm can save space as much as possible to avoid the rivet seat 23 being damaged by the riveting process. D4 is preferably 4mm, 6mm and 8mm.

[0140] Optionally, the diameter of the conductive hole 11 is D1, the diameter of the rivet seat 23 is D4, and 130%≤D4 / D1≤200%.

[0141] The selection of the rivet seat 23 should also refer to the conductive hole 11. When the rivet seat 23 is too small, there is a risk that the rivet seat 23 will be directly inserted into the conductive hole 11 due to interference fit with the conductive hole 11, and if the rivet seat 23 is too large, it will occupy extra space. 130%≤D4 / D1≤200% is the preferred solution. Under the premise that the processing accuracy allows, D4 / D1 is preferably 130%, 132%, or 135%.

[0142] Optionally, the thickness of the rivet seat 23 is L8, 0.05mm≤L8≤2mm.

[0143] The thickness of the rivet seat 23 also affects the pressure bearing capacity during the riveting process. A too thin rivet seat 23 is easily broken during the riveting process, while an overly large rivet seat 23 will occupy extra space. Therefore, 0.05mm≤L8≤2mm can save space as much as possible to avoid the rivet seat 23 being damaged by the riveting process. L8 is preferably 0.1mm, 0.5mm and 1mm.

[0144] Specifically, the diameter of the rivet seat 23 is D4, the outer diameter of the isolation ring 60 is D5, and 70%≤D4 / D5≤120%.

[0145] The diameter of the rivet seat 23 and the outer diameter of the isolation ring 60 should be as close as possible. If the size difference between the two is too large, redundant structures will be generated, affecting the space utilization of the single battery and increasing the additional production cost. 70% ≤ D4 / D5 ≤ 120%. Under the premise of machining accuracy, D4 / D5 can be selected as 95%, 98% or 100%. D4 ≤ D5 can avoid electrochemical corrosion caused by the rivet seat 23 and the working surface facing each other.

[0146] Specifically, the thickness of the isolation ring 60 is L9, 0.5≤L9≤1.5 mm.

[0147] The thickness of the isolation ring 60 is an important parameter that affects its insulation and sealing performance. An isolation ring 60 that is too thin cannot be well sealed and is easily squeezed and damaged during riveting. An isolation ring 60 that is too thick will occupy extra space and affect the space utilization of the single battery.

[0148] In some embodiments of the present application, a rivet hole 242 is further formed on the riveted second conductive member 20 , and the opening direction of the rivet hole 242 is toward a side of the second conductive member 20 away from the battery cell assembly 30 .

[0149] The provision of the riveting hole 242 facilitates the insertion of the riveting machine punch and also facilitates the rivet buckle 24 to be rolled around, thereby reducing the risk of the second conductive member 20 being damaged due to the riveting process.

[0150] Furthermore, an inner chamfer 243 is provided at the edge of the rivet hole 242 , and on any cross section passing through the axis of the rivet hole 242 , the included angle between the plane of the inner chamfer 243 and the appearance surface is A2, 30°≤A2≤85°.

[0151] The setting of the inner chamfer 243 is beneficial to guiding the alignment of the riveting machine punch and the riveting hole 242. If A2 is too large, the outer edge of the inner chamfer 243 will be too narrow and the guiding effect will be insufficient. If A2 is too small, the punch and the inner chamfer 243 will collide and guidance will be impossible. 30°≤A2≤85° can ensure a better guiding effect. The most preferred A2 is 40°, 45°, and 48°.

[0152] Optionally, the diameter of the riveting hole 242 is D6, the minimum outer diameter of the second conductive member 20 is D7, and 30%≤D6 / D7≤80%.

[0153] The diameter of the rivet hole 242 is limited by the outer diameter of the second conductive member 20. A larger rivet hole 242 makes the hole wall of the rivet hole 242 thinner, making the riveting process easier to perform. However, an oversized rivet hole 242 will make the wall thickness of the second conductive member 20 where the rivet hole 242 is opened too thin, affecting the strength and current carrying capacity of the second conductive member 20. The value selection of 30%≤D6 / D7≤80% can make the riveting process as easy as possible while ensuring the strength and current carrying capacity of the second conductive member 20. The most preferred value of D6 / D7 is 40% or 50%.

[0154] Please also read Figure 8 As shown, Figure 8 yes Figure 2 A partial enlarged view of area B.

[0155] In some embodiments of the present application, the first conductive member 10 is further formed with a pressure relief groove 12 , and the pressure relief groove 12 is recessed on the surface of the first conductive member 10 to avoid the conductive hole 11 .

[0156] The provision of the pressure relief groove 12 reduces the structural strength of the first conductive member 10 in the corresponding area, making it a structural weakness of the single cell housing. When an unexpected situation occurs inside the single cell, such as thermal runaway, causing the internal pressure to rise, the first conductive member 10 in the pressure relief groove 12 area is destroyed, and the internal pressure of the single cell is released, thereby avoiding the occurrence of explosion due to excessive accumulation of internal pressure.

[0157] Furthermore, the distance between the edge of the pressure relief groove 12 and the edge of the conductive hole 11 is L10, 2mm<L10<35mm.

[0158] The pressure relief groove 12 is arranged to avoid the conductive hole 11. The distance between the edge of the pressure relief groove 12 and the edge of the conductive hole 11 will have an additional impact on the structural strength of the first conductive member 10. When the pressure relief groove 12 and the conductive hole 11 are too close, there is a risk of cracking of the pressure relief groove 12 when the second conductive member 20 is assembled. 2mm<L10<35mm can ensure the stability of the assembly of the second conductive member 20 under the premise of the structure being as tight as possible. L10 is preferably 2mm, 3mm or 5mm.

[0159] Optionally, the maximum width of the pressure relief groove 12 is L11, 0.05 mm ≤ L11 ≤ 5 mm.

[0160] The width of the pressure relief groove 12 affects the distribution of the structural weak surface formed by it. If the pressure relief groove 12 is too narrow, the pressure relief effect will be weak. If the pressure relief groove 12 is too wide, it will have a greater impact on the structural strength of the first conductive member 10, so that it is also at risk of rupture under normal use conditions. 0.05mm≤L11≤5mm can meet the pressure relief function of the pressure relief groove 12 while ensuring the structural strength of the first conductive member 10. L11 is preferably 0.1mm or 0.2mm.

[0161] Optionally, the pressure relief groove 12 is opened on the exterior surface.

[0162] The pressure relief groove 12 is opened on the exterior surface. When the internal pressure of the single cell rises, the working surface of the first conductive member 10 is pressurized, the first conductive member 10 bulges outward, and the pressure relief groove 12 tends to open. There is also stress concentration at the bottom of the pressure relief groove 12, which is conducive to the destruction of the first conductive member 10 when the internal pressure of the single cell rises.

[0163] Specifically, the distance between the bottom of the pressure relief groove 12 and the working surface is L12, 0.02mm≤L12≤1.5mm.

[0164] If the distance between the bottom of the pressure relief groove 12 and the working surface is too large, the pressure relief effect will be weak. If the distance between the bottom of the pressure relief groove 12 and the working surface is too small, the structural strength of the first conductive member 10 will be greatly affected, and there is a risk of rupture under normal use conditions. 0.02mm≤L12≤1.5mm can meet the pressure relief function of the pressure relief groove 12 while ensuring the structural strength of the first conductive member 10. L12 is preferably 0.1mm or 0.15mm.

[0165] It should be noted that the bottom here does not refer to a specific plane, but should be understood as the position closest to the working surface in the pressure relief groove 12, and the shape of this embodiment cannot be limited to this.

[0166] Optionally, the included angle between the pressure relief groove 12 and the two groove walls is A3, 20°≤A3≤90°.

[0167] The angle A3 is related to the stress concentration at the bottom of the pressure relief groove 12. When the angle A3 is too small, the stress concentration at the bottom of the pressure relief groove 12 will be more obvious, and the first conductive member 10 will also crack when the single cell generates heat during normal operation. If the angle A3 is too large, the width of the widest part of the pressure relief groove 12 will be too large, which will also affect the strength of the first conductive member 10. It is found through experiments that 20°≤A3≤90° is a better angle range, and A3 is further preferably 50° or 60°.

[0168] Please also read Fig. 9 As shown, Fig. 9 It is a schematic diagram of the coordination between the pressure relief groove 12 and the second conductive member 20 provided in another embodiment of the present invention.

[0169] Optionally, the cross section of the pressure relief groove 12 perpendicular to the extension direction thereof is a trapezoid, and the lower base of the trapezoid is located on the surface of the first conductive member 10 .

[0170] The presence of a plane at the bottom of the pressure relief groove 12 can alleviate stress concentration to a certain extent, enhance the structural strength of the first conductive member 10 while keeping the depth of the pressure relief groove 12 and the thickness of the first conductive member 10 unchanged, and avoid accidental damage to the first conductive member 10 during normal use.

[0171] Specifically, the length of the upper base of the trapezoid is L13, 0.02mm≤L13≤3mm.

[0172] If the length of the upper bottom is too small, the effect of relieving stress concentration will not be obvious enough. If the length of the upper bottom is too large, the pressure relief groove 12 will be too wide, which will also affect the structural strength of the first conductive member 10. 0.02mm≤L13≤3mm is the value range that is not easy to produce stress concentration under the premise of maintaining a narrow pressure relief groove 12. L13 is preferably 1mm.

[0173] Please also read Fig.10 As shown, Fig.10 It is a schematic diagram of the coordination between the pressure relief groove 12 and the second conductive member 20 provided in another embodiment of the present invention.

[0174] Optionally, the bottom of the pressure relief groove 12 has rounded corners.

[0175] The rounded corners at the bottom of the pressure relief groove 12 can alleviate stress concentration to a certain extent, enhance the structural strength of the first conductive member 10 while keeping the depth of the pressure relief groove 12 and the thickness of the first conductive member 10 unchanged, and avoid accidental damage to the first conductive member 10 during normal use.

[0176] Specifically, the radius of the fillet is R1, the maximum width of the pressure relief groove 12 is L11, and 20%≤R1 / L11≤100%.

[0177] If the radius of the fillet is too small, the effect of relieving stress concentration will not be obvious enough. If the radius of the fillet is too large, the pressure relief groove 12 will be too wide, which will also affect the structural strength of the first conductive member 10. 20%≤R1 / L11≤100% is the value range that is not prone to stress concentration while maintaining a narrow pressure relief groove 12. R1 / L11 is preferably 50%.

[0178] Please also read Fig.11 As shown, Fig.11 It is a schematic diagram of the coordination of the first conductive member 10, the second conductive member 20, the isolation ring 60 and the second isolation layer 52 provided in an embodiment of the present invention.

[0179] In some embodiments of the present application, the single battery further includes a second isolation layer 52 , and the second isolation layer 52 covers a surface of the first conductive member 10 facing the battery cell assembly 30 .

[0180] The second isolation layer 52 covers the surface of the first conductive member 10 facing the battery cell assembly 30 , isolating the first conductive member 10 at least partially from the electrolyte, thereby alleviating the corrosion rate of the first conductive member 10 and extending the service life of the single battery.

[0181] Exemplarily, the second isolation layer 52 is a nickel plating layer or an iron alloy plating layer.

[0182] The nickel plating layer or iron alloy plating layer has electrical conductivity. When the second isolation layer 52 is sandwiched between the first conductive member 10 and the second conductive member 20, the second isolation layer 52 can share part of the current, isolating the first conductive member 10 and the second conductive member 20 immersed in the electrolyte area without significantly affecting the current carrying capacity of the single cell.

[0183] Exemplarily, the second isolation layer 52 is a PP film or PPS.

[0184] PP film and PPS film are relatively mature protective materials in the lithium battery field, with low cost and high processing efficiency.

[0185] Specifically, the area of ​​the first conductive member 10 close to the battery cell assembly 30 is S1, the projection area of ​​the second isolation layer 52 on the surface of the first conductive member 10 is S8, and 5%≤S8 / S1≤97%.

[0186] The area ratio of the second isolation layer 52 is related to its isolation capability, and 5%≤S8 / S1≤97% is an optimal value range in experiments.

[0187] Specifically, the thickness of the second isolation layer 52 is L14, 0.05 mm≤L14≤2 mm.

[0188] The isolation effect of the second isolation layer 52 is positively correlated with its thickness. A second isolation layer 52 that is too thin has the risk of being penetrated, and a second isolation layer 52 that is too thick will cause additional space occupation and increase in production costs. 0.05mm≤L14≤2mm is a value range that minimizes space occupation while ensuring the isolation effect.

[0189] Specifically, the thickness of the second isolation layer 52 is evenly distributed on the entire surface of the first conductive member 10 .

[0190] The evenly distributed second isolation layer 52 has a uniform isolation effect, a simple processing technology and high production efficiency.

[0191] Please also read Fig.12 As shown, Fig.12 It is a schematic diagram of the coordination of the first conductive member 10, the second conductive member 20, the isolation ring 60 and the second isolation layer 52 provided by another embodiment of the present invention.

[0192] Optionally, the thickness of the second isolation layer 52 increases as it approaches the conductive hole 11 .

[0193] There are multiple component abutment surfaces near the conductive hole 11 , and a larger thickness of the second isolation layer 52 applied at the conductive hole 11 can effectively enhance the isolation effect in the corresponding area.

[0194] In some embodiments of the present application, the thickness of the first conductive member 10 is L11, 0.5 mm ≤ L11 ≤ 2 mm.

[0195] The first conductive part 10 has the functions of conduction and physical protection. A first conductive part 10 that is too thin will have poor current carrying capacity and structural strength, while a first conductive part 10 that is too thick will increase production costs and cause additional weight and volume. 0.5mm≤L11≤2mm is a value range that can maintain good structural strength and current carrying capacity while minimizing space occupancy, and L11 is preferably 1mm.

[0196] It should be noted that the first conductive member 10 may be formed by splicing a plurality of plates, each of which is located in a different plane. In this case, L11 should be defined as the thickness of the plate rather than the distance between the two farthest plate surfaces.

[0197] Please also read Fig.13 As shown, Fig.13 It is a schematic diagram of the connection relationship between the first conductive member 10 and the housing 70 provided in an embodiment of the present invention.

[0198] In some embodiments of the present application, the single battery further includes a shell 70 , one side of the shell 70 is open, the first conductive member 10 blocks the opening of the shell 70 and together with the shell 70 forms an accommodating space, and the battery cell assembly 30 is disposed in the accommodating space.

[0199] The first conductive member 10 blocks the opening and encloses the shell 70 to form an accommodating space, and the battery cell assembly 30 is arranged in the accommodating space, so that the connection between the first conductive member 10 and the second conductive member 20 can be completed first. When the first conductive member 10 is buckled into the shell 70, the second conductive member 20 abuts against the battery cell assembly 30. Alternatively, the first conductive member 10, the shell 70 and the battery cell assembly 30 are assembled first, and then the second conductive member 20 is inserted into the conductive hole 11 and abuts against the battery cell assembly 30, and the assembly process is more flexible.

[0200] Furthermore, the single cell further includes a second weld 42 , and the first conductive member 10 and the cover plate are connected via the second weld 42 .

[0201] The first conductive member 10 and the cover plate are connected via the second weld 42, which ensures the connection strength and air tightness of the single cell housing. Moreover, since the second weld 42 assumes a considerable part of the connection function, the requirement for the welding strength between the second conductive member 20 and the battery cell assembly 30 is reduced in disguise, making it less likely for the second conductive member 20 and the battery cell assembly 30 to be short-circuited.

[0202] Specifically, the height of the second weld 42 protruding from the surface of the shell 70 is H3, 0mm≤H3≤3mm.

[0203] The portion of the second weld 42 protruding from the surface of the shell 70 will increase the probability of scratches on adjacent single cells in the battery pack. Therefore, 0mm≤H3≤3mm is configured to protect the single cells and extend the service life of the single cells. If conditions permit, a grinder can also be used to make H3 as close to 0mm as possible.

[0204] Specifically, the width of the second weld 42 is L15, 2mm≤L15≤6mm.

[0205] Because the mechanical properties of the weld are usually greater than those of the parent material, a sufficiently large width of the second weld 42 can ensure the connection strength between the shell 70 and the first conductive component 10. However, due to the limitations of the strength of the shell 70 and the first conductive component 10 themselves, an excessively large second weld 42 cannot improve the overall strength of the single cell housing. 2mm≤L15≤6mm can minimize energy waste while ensuring the connection strength between the first conductive component 10 and the shell 70.

[0206] Optionally, the first conductive member 10 includes a first plate 13, a second plate 14 and a third plate 15, the conductive hole 11 is opened in the first plate 13, the third plate 15 is wrapped around the first plate 13, the shell 70 is connected to the third plate 15, the opposite ends of the second plate 14 are respectively connected to the first plate 13 and the third plate 15, and the first plate 13 and the second plate 14 are embedded in the opening of the shell 70.

[0207] The first plate 13 and the second plate 14 are embedded in the opening of the shell 70, and the first conductive part 10 and the shell 70 can be positioned without a mold before the third plate 15 and the shell 70 are welded, which serves as an anti-foolproof structure and avoids the risk of the assembler installing the first conductive part 10 upside down.

[0208] Furthermore, the first plate 13 and the second plate 14 are connected by an arc.

[0209] When the inner edge of the opening of the shell 70 abuts against the arc, there is a tendency to spontaneously guide the first plate 13 and the second plate 14 into the opening, which can guide assembly in addition to positioning, thereby reducing the requirements for alignment accuracy during the assembly process.

[0210] Specifically, the radius of the arc is R2, 0.1 mm ≤ R2 ≤ 2 mm.

[0211] Too small an arc radius results in a smaller alignment guiding area and weaker guiding effect, while too large an arc radius reduces the connection strength between the first plate 13 and the second plate 14. 0.1 mm ≤ R2 ≤ 2 mm can obtain as obvious a guiding effect as possible while ensuring the structural strength of the first conductive member 10, and R2 is preferably 0.5 mm or 1 mm.

[0212] Specifically, the radius of the arc is R2, the thickness of the first plate 13 is L16, and 20%≤R2 / L16≤100%.

[0213] The radius of the arc is also affected by the thickness of the first plate 13. A too small arc radius results in a smaller alignment guide area and a weaker guide effect, while a too large arc radius reduces the connection strength between the first plate 13 and the second plate 14. 20%≤R2 / L16≤100% can obtain as obvious a guide effect as possible while ensuring the structural strength of the first conductive member 10, and R2 / L16 is preferably 50%.

[0214] Optionally, an assembly gap 80 exists between the second plate 14 and the housing 70 .

[0215] The existence of the assembly gap 80 facilitates the embedding of the first plate 13 and the second plate 14 and reduces the alignment accuracy requirement during the assembly process.

[0216] Specifically, the width of the assembly gap 80 is L17, and 0.1 mm≤L17≤0.5 mm.

[0217] An assembly gap 80 that is too small is unlikely to produce significant optimization for the assembly process, while an assembly gap 80 that is too large will affect the airtightness between the first conductive member 10 and the housing 70. Therefore, the configuration of 0.1mm≤L17≤0.5mm can reduce the alignment accuracy requirement as much as possible while ensuring airtightness, and L17 is preferably 0.4mm or 0.5mm. It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0218] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element through an intermediate element.

[0219] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0220] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the design concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A single cell battery, characterized in that: include: A first conductive member, comprising a working surface and an appearance surface arranged opposite to each other, wherein the first conductive member is provided with an electrical conduction hole, the electrical conduction hole passes through the working surface and the appearance surface, and the working surface faces the interior of the single battery; The second conductive member includes a rivet post and a rivet seat and a rivet buckle connected to two ends of the rivet post, the rivet post passes through the conductive hole, and the rivet buckle is riveted to the appearance surface; An isolation ring is sleeved on the rivet column, and the rivet seat and the working surface sandwich the isolation ring; The battery cell assembly is connected to the second conductive member by welding.

2. The single cell according to claim 1, characterized in that: A welding hole is also formed on the second conductive member, and the opening direction of the welding hole is toward a side of the second conductive member away from the battery core assembly.

3. The single cell according to claim 2, characterized in that: The diameter of the conductive hole is D1, the diameter of the welding hole is D2, and 30%≤D2 / D1≤90%.

4. The single cell according to claim 2, characterized in that: The depth of the welding hole is L1, the projection length of the second conductive member in the thickness direction of the first conductive member is L2, and 50%≤L1 / L2≤90%.

5. The single cell according to claim 2, characterized in that: The minimum distance between the hole wall of the welding hole and the outer wall of the second conductive member is L3, and L3≥0.05 mm.

6. The single cell according to claim 2, characterized in that: The distance between the bottom of the welding hole and the surface of the second conductive member on one side close to the battery core assembly is L4, and 0.05mm≤L4≤2mm.

7. The single cell according to claim 1, characterized in that: The battery cell assembly includes a battery cell and a busbar, and the busbar is electrically connected to the battery cell and the second conductive member respectively.

8. The single cell according to claim 7, characterized in that: The area of ​​the working surface is S1, the projected area of ​​the contact surface between the second conductive member and the busbar on the working surface is S2, and 20%≤S2 / S1≤90%.

9. The single cell according to claim 7, characterized in that: The second conductive member is connected to the busbar via a first weld, a projection area of ​​the first weld on the surface of the busbar is S3, a surface area of ​​the busbar close to the first conductive member structure is S4, and S3 / S4≥10%.

10. The single cell according to claim 7, characterized in that: The second conductive member is welded to a side of the busbar close to the first conductive member, and a side of the busbar away from the second conductive member is electrically connected to the battery cell.

11. The single cell according to claim 7, characterized in that: The second conductive member and the busbar are made of the same material.

12. The single cell according to claim 1, characterized in that: The battery cell assembly comprises a winding core and a pole tab which are electrically connected, and the pole tab is welded to the second conductive member.

13. The single cell according to claim 12, characterized in that: The second conductive member and the tab are made of the same material.

14. The single cell according to claim 1, characterized in that: There are a plurality of the conductive holes, and the second conductive members are arranged corresponding to the conductive holes one by one.

15. The single cell according to claim 14, characterized in that: A plurality of the electrical conductive holes are arranged in a circular array on the first conductive member.

16. The single cell according to claim 1, characterized in that: The material of the second conductive member includes copper.

17. The single cell according to claim 16, characterized in that: The single cell further includes a first isolation layer, the first isolation layer wraps the second conductive member, and the rivet seat is at least partially exposed.

18. The single cell according to claim 17, characterized in that: The material of the first isolation layer includes at least one of steel and nickel.

19. The single cell according to claim 17, characterized in that: The area of ​​the exposed portion of the rivet seat is S5, the area of ​​the first conductive member close to the battery core assembly is S1, and 40%≤S5 / S1≤100%.

20. The single cell according to any one of claims 1 to 19, characterized in that: The diameter of the rivet seat is D4, the outer diameter of the isolation ring is D5, and 70%≤D4 / D5≤120%.

21. The single cell according to any one of claims 1 to 19, characterized in that: The thickness of the isolation ring is L9, 0.5≤L9≤1.5mm.

22. The single cell according to any one of claims 1 to 19, characterized in that: An outer edge of one end of the rivet button away from the rivet seat is provided with an outer chamfer, and on any cross section passing through the axis of the rivet button, an included angle between the outer chamfer and the appearance surface is A1, 10°≤A1≤85°.

23. The single cell according to claim 22, characterized in that: The distance between the outer edge of the outer chamfer and the appearance surface is L5, the thickness of the rivet is L6, and 0≤L5 / L6≤70%.

24. The single cell according to any one of claims 1 to 19, characterized in that: The thickness of the rivet button is L6, the projection length of the second conductive member in the thickness direction of the rivet button is L7, and 10%≤L6 / L7≤40%.

25. The single cell according to any one of claims 1 to 19, characterized in that: The diameter of the conductive hole is D1, the outer diameter of the rivet button is D3, and 120%≤D3 / D1≤200%.

26. The single cell according to any one of claims 1 to 19, characterized in that: The diameter of the rivet seat is D4, 2mm≤D4≤20mm.

27. The single cell according to any one of claims 1 to 19, characterized in that: The diameter of the conductive hole is D1, the diameter of the rivet seat is D4, and 130%≤D4 / D1≤200%.

28. The single cell according to any one of claims 1 to 19, characterized in that: The thickness of the rivet seat is L8, 0.05mm≤L8≤2mm.

29. The single cell according to any one of claims 1 to 19, characterized in that: A rivet hole is also formed on the second conductive member, and the opening direction of the rivet hole is toward a side of the second conductive member away from the battery core assembly.

30. The single cell according to claim 29, characterized in that: The edge of the riveting hole is provided with an inner chamfer, and on any cross section passing through the axis of the riveting hole, the angle between the inner chamfer plane and the appearance surface is A2, 30°≤A2≤85°.

31. The single cell according to claim 29, characterized in that: The diameter of the riveting hole is D6, the minimum outer diameter of the second conductive member is D7, and 30%≤D6 / D7≤80%.

32. The single cell according to any one of claims 1 to 31, characterized in that: The first conductive member is further formed with a pressure relief groove, and the pressure relief groove is recessed on the surface of the first conductive member to avoid the electrical conduction hole.

33. The single cell according to claim 32, characterized in that: The distance between the edge of the pressure relief groove and the edge of the conductive hole is L10, 2mm<L10<35mm.

34. The single cell according to claim 32, characterized in that: The maximum width of the pressure relief groove is L11, 0.05mm≤L11≤5mm.

35. The single cell according to claim 32, characterized in that: The pressure relief groove is arranged on the exterior surface.

36. The single cell according to claim 35, characterized in that: The distance between the bottom of the pressure relief groove and the working surface is L12, 0.02mm≤L12≤1.5mm.

37. The single cell according to claim 32, characterized in that: The included angle of the pressure relief groove relative to the two groove walls is A3, 20°≤A3≤90°.

38. The single cell according to claim 32, characterized in that: The cross section of the pressure relief groove perpendicular to the extension direction thereof is a trapezoid, and the lower base of the trapezoid is located on the surface of the first conductive member.

39. The single cell according to claim 38, characterized in that: The upper base length of the trapezoid is L13, 0.02mm≤L13≤3mm.

40. The single cell according to claim 32, characterized in that: The bottom of the pressure relief groove has a rounded corner.

41. The single cell according to claim 40, characterized in that: The radius of the fillet is R1, the maximum width of the pressure relief groove is L11, and 20%≤R1 / L11≤100%.

42. The single cell according to any one of claims 1 to 31, characterized in that: The single battery further includes a second isolation layer, and the second isolation layer covers a surface of the first conductive member on one side facing the battery core assembly.

43. The single cell according to claim 42, characterized in that: The second isolation layer is a nickel plating layer or an iron alloy plating layer.

44. The single cell according to claim 42, characterized in that: The second isolation layer is one of a PP film and a PPS film.

45. The single cell according to claim 42, characterized in that: The area of ​​the first conductive member close to the battery core assembly is S1, the projection area of ​​the second isolation layer on the surface of the first conductive member is S8, and 5%≤S8 / S1≤97%.

46. ​​The single cell according to claim 42, characterized in that: The thickness of the second isolation layer is L14, 0.05 mm ≤ L14 ≤ 2 mm.

47. The single cell according to claim 42, characterized in that: The thickness of the second isolation layer is evenly distributed on the entire surface of the first conductive member.

48. The single cell according to claim 42, characterized in that: The thickness of the second isolation layer increases as it approaches the conductive hole.

49. The single cell according to any one of claims 1 to 31, characterized in that: The single battery further comprises a shell, one side of which is open, the first conductive member blocks the opening of the shell and is combined with the shell to form an accommodating space, and the battery cell assembly is arranged in the accommodating space.

50. The single cell according to claim 49, characterized in that: The single battery cell further includes a second weld, and the first conductive member and the cover plate are connected via the second weld.

51. The single cell according to claim 50, characterized in that: The height of the second weld protruding from the shell surface is H3, 0mm≤H3≤3mm.

52. The single cell according to claim 50, characterized in that: The width of the second weld is L15, 2mm≤L15≤6mm.

53. The single cell according to claim 49, characterized in that: The first conductive member includes a first plate, a second plate and a third plate, the conductive hole is opened in the first plate, the third plate is wound around the first plate, the shell is connected to the third plate, the opposite ends of the second plate are respectively connected to the first plate and the third plate, and the first plate and the second plate are embedded in the opening of the shell.

54. The single cell according to claim 53, characterized in that: The first plate and the second plate are connected by an arc.

55. The single cell according to claim 54, characterized in that: The radius of the arc is R2, 0.1mm≤R2≤2mm.

56. The single cell according to claim 54, characterized in that: The radius of the arc is R2, the thickness of the first plate is L16, and 20%≤R2 / L16≤100%.

57. The single cell according to claim 53, characterized in that: An assembly gap exists between the second plate and the housing.

58. The single cell according to claim 57, characterized in that: The width of the assembly gap is L17, 0.1mm≤L17≤0.5mm.

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