Single battery

Abstract

The utility model discloses a single battery which comprises a first conductive piece, a second conductive piece and a battery cell assembly, specifically, the first conductive piece is provided with a conductive hole, and the conductive hole penetrates through the first conductive piece in the thickness direction of the first conductive piece; the second conductive piece penetrates through the conductive hole, and the second conductive piece and the first conductive piece are fixed and electrically connected; and the battery core assembly is welded with the second conductive piece. Compared with the prior art, the material selection of the second conductive part is slightly limited by the structural strength, and the welding performance of the second conductive part and the battery cell assembly is good.

Description

Technical Field

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

[0002] The busbar is a crucial component of a battery, responsible for collecting and converging current from the cells. The casing, another important part of the battery, functions to seal and protect the internal structure. Due to their different functions, they are typically made of different materials. A common configuration is a copper busbar paired with an aluminum alloy casing. Because of the significant differences in melting points and fluidity between the two, welding the busbar and casing presents certain challenges, easily leading to incomplete soldering on one side or overheating on the other, which affects the battery's electrical performance and lifespan. Utility Model Content

[0003] One objective of this invention is to provide a single-cell battery that addresses the technical problem of poor welding results due to difficulty in matching parameters when welding the casing and the busbar.

[0004] To achieve the above objectives, the present invention provides a solution as follows: a single-cell battery, comprising a first conductive element, a second conductive element, and a cell assembly. Specifically, the first conductive element has a conductive hole that penetrates the first conductive element in the thickness direction; the second conductive element passes through the conductive hole and is fixed and electrically connected to the first conductive element; the cell assembly is welded to the second conductive element.

[0005] In some embodiments of this application, a welding hole is also formed on the second conductive element, and the opening direction of the welding hole is towards the side of the second conductive element away from the cell assembly.

[0006] In some embodiments of this 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 this application, the depth of the welding hole is L1, the projection length of the second conductive element in the thickness direction of the first conductive element is L2, and 50% ≤ L1 / L2 ≤ 90%.

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

[0009] In some embodiments of this application, the distance between the bottom of the welding hole and the surface of the second conductive element near the cell assembly is L4, where 0.05mm≤L4≤2mm.

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

[0011] In some embodiments of this application, the area of ​​the first conductive element near the cell assembly is S1, and the projected area of ​​the contact surface between the second conductive element and the busbar on the first conductive element is S2, where 20% ≤ S2 / S1 ≤ 90%.

[0012] In some embodiments of this application, the second conductive element is connected to the busbar by a first weld, the projected area of ​​the first weld on the surface of the busbar is S3, the surface area of ​​the busbar on the side closer to the structure of the first conductive element is S4, and S3 / S4≥10%.

[0013] In some embodiments of this application, the second conductive element is welded to the side of the busbar closer to the first conductive element, and the side of the busbar away from the second conductive element is electrically connected to the battery cell.

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

[0015] In some embodiments of this application, the battery cell assembly includes an electrically connected core and a tab, with the tab and a second conductive element welded together.

[0016] In some embodiments of this application, the second conductive element and the electrode tab are made of the same material.

[0017] In some embodiments of this application, there are multiple conductive holes, and the second conductive element is provided in a corresponding manner to each conductive hole.

[0018] In some embodiments of this application, a plurality of conductive holes are arranged in a circumferential array on the first conductive element.

[0019] In some embodiments of this application, the material of the second conductive element is copper.

[0020] In some embodiments of this application, the single cell further includes a first insulating layer that encloses a second conductive element, with at least a partial exposure of the side of the second conductive element closest to the cell assembly.

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

[0022] In some embodiments of this application, the area of ​​the exposed portion of the second conductive element on the side near the cell assembly is S5, and the area of ​​the first conductive element on the side near the cell assembly is S1, where 40% ≤ S5 / S1 ≤ 100%.

[0023] In some embodiments of this application, the second conductive element and the first conductive element are riveted together.

[0024] In some embodiments of this application, the first conductive element includes a first surface and a second surface opposite to each other, and the second conductive element includes a rivet base, a rivet post and a rivet buckle connected in sequence. Specifically, the rivet post has a conductive hole; the rivet base is connected to one end of the rivet post and abuts against the first surface; the rivet buckle is connected to the end of the rivet post away from the rivet base and is riveted to the second surface.

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

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

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

[0028] In some embodiments of this 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 this application, the diameter of the rivet base is D4, where 2mm≤D4≤20mm.

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

[0031] In some embodiments of this application, the thickness of the rivet base is L8, where 0.05mm≤L8≤2mm.

[0032] In some embodiments of this application, the single cell further includes a first isolation sleeve, a rivet post passing through the first isolation sleeve, and a rivet base and a first surface clamping the first isolation sleeve.

[0033] In some embodiments of this application, the diameter of the rivet base is D4, the outer diameter of the first isolation sleeve is D5, and 70% ≤ D4 / D5 ≤ 120%.

[0034] In some embodiments of this application, the thickness of the first isolation sleeve is L9, where 0.5 ≤ L9 ≤ 1.5 mm.

[0035] In some embodiments of this application, a riveting hole is also formed on the second conductive member, and the opening direction of the riveting hole is towards the side of the second conductive member away from the battery cell assembly.

[0036] In some embodiments of this application, the edge of the rivet hole is provided with an inner chamfer. On any cross section passing through the axis of the rivet hole, the angle between the inner chamfer plane and the second surface is A2, where 30°≤A2≤85°.

[0037] In some embodiments of this application, the diameter of the rivet hole is D6, the minimum outer diameter of the second conductive element is D7, and 30% ≤ D6 / D7 ≤ 80%.

[0038] In some embodiments of this application, the single cell further includes a fastener, the second conductive element includes a through post and a stop, the through post passes through the conductive hole, the stop abuts against the first conductive element, and the fastener passes through at least one of the first conductive element and the second conductive element to achieve the connection between the first conductive element and the second conductive element.

[0039] In some embodiments of this application, a first hole is provided on the edge, and a fastener passes through the first hole and is connected to the first conductive element.

[0040] In some embodiments of this application, a second isolation layer is provided between the first conductive element and the second conductive element.

[0041] In some embodiments of this application, the second isolation layer is at least one of PP film or PPS film.

[0042] In some embodiments of this application, a third insulating layer is provided on the surface of the fastener that contacts the first conductive element and the second conductive element.

[0043] In some embodiments of this application, the third isolation layer is a nickel plating layer.

[0044] In some embodiments of this application, the distance between the surface of the through post near the cell assembly and the surface of the first conductive element near the cell assembly is H1, where 0.8 ≤ H1 ≤ 2 mm.

[0045] In some embodiments of this application, the projected area of ​​the outer edge of the stop on the first conductive element is S6, the contact area between the stop and the first conductive element is S7, and 5% ≤ S7 / S6 ≤ 35%.

[0046] In some embodiments of this application, there are multiple first holes on each flange.

[0047] In some embodiments of this application, a plurality of first holes are distributed in a circumferential array on the retaining edge.

[0048] In some embodiments of this application, the retaining edge abuts against the side of the first conductive element away from the cell assembly.

[0049] In some embodiments of this application, the diameter of the first hole is D8, where 2.5mm ≤ D8 ≤ 16mm.

[0050] In some embodiments of this application, the first conductive element is provided with a second hole, and the fastener passes through the first hole and is inserted into the second hole.

[0051] In some embodiments of this application, the fastener is a screw, and the fastener is threaded into the second hole.

[0052] In some embodiments of this application, the fastener includes a first part and a second part that are connected to each other. The first part passes through a first hole, and the second part abuts against the side of the second conductive member away from the first conductive member.

[0053] In some embodiments of this application, the diameter of the first part is D9, where 2.5mm ≤ D9 ≤ 16mm.

[0054] In some embodiments of this application, the thickness of the second part is L10, where 0.5mm ≤ L10 ≤ 2mm.

[0055] In some embodiments of this application, a third hole is provided on the first conductive element, and a fastener passes through the third hole and is connected to the second conductive element.

[0056] In some embodiments of this application, the single cell further includes a second insulating sleeve, which is sleeved on the through post, and the first conductive element and the second conductive element at least partially sandwich the second insulating sleeve.

[0057] In some embodiments of this application, the first conductive element includes a plate and a boss, a conductive hole is formed in the plate, the boss protrudes from the inner wall of the conductive hole, and a second isolation sleeve is sandwiched between the boss and the guard.

[0058] In some embodiments of this application, the height of the boss is H2, where 0.5mm < H2 ≤ 5mm.

[0059] In some embodiments of this application, the height of the boss is H2, the thickness of the first conductive element is L11, and 20% ≤ H2 / L11 ≤ 50%.

[0060] In some embodiments of this application, the height of the boss is H2, the thickness of the first conductive element is L11, the natural length of the second insulating sleeve is L12, and H2+L12>L11.

[0061] In some embodiments of this application, the second isolation sleeve includes a ring sleeve portion and a gasket portion, the ring sleeve portion being at least partially inserted into the electrical conductivity hole, and the gasket portion being at least partially clamped by a retaining edge and a first conductive element.

[0062] In some embodiments of this application, the outer diameter of the gasket portion is D10, the outer diameter of the retaining edge is D11, and 70% ≤ D11 / D10 ≤ 120%.

[0063] In some embodiments of this application, the thickness of the gasket portion is L13, where 0.5 ≤ L13 ≤ 1.5 mm.

[0064] In some embodiments of this application, the second conductive element passes through the conductive hole and is snapped together with the first conductive element.

[0065] In some embodiments of this application, the first conductive element includes a first surface and a second surface disposed opposite to each other, and the second conductive element includes a base, a connecting rod and a buckle connected in sequence, the connecting rod having a conductive hole passing through it; the base is connected to one end of the connecting rod and abuts against the second surface; the buckle is connected to the end of the connecting rod away from the base and is engaged with the first surface.

[0066] In some embodiments of this application, the outer diameter of the base is D12, where 2mm≤D12≤20mm.

[0067] In some embodiments of this application, the diameter of the conductive hole is D1, the outer diameter of the base is D12, and 130% ≤ D12 / D1 ≤ 200%.

[0068] In some embodiments of this application, the thickness of the base is L14, where 0.2mm≤L14≤2mm.

[0069] In some embodiments of this application, the outer diameter of the buckle decreases as it moves away from the base.

[0070] In some embodiments of this application, the diameter of the conductive hole is D1, the maximum outer diameter of the buckle is D13, and 102% ≤ D13 / D1 ≤ 150%.

[0071] In some embodiments of this application, the diameter of the conductive hole is D1, the minimum outer diameter of the buckle is D14, and 60% ≤ D14 / D1 ≤ 97%.

[0072] In some embodiments of this application, on any cross section passing through the buckle axis, the angle between the tangent of the buckle's outer contour and the first surface is A3, where 60% ≤ A3 ≤ 85%.

[0073] In some embodiments of this application, the single cell further includes a second insulating sleeve, which is sleeved on the through post, and the first conductive element and the second conductive element at least partially sandwich the second insulating sleeve.

[0074] In some embodiments of this application, the first conductive element includes a plate and a boss, a conductive hole is formed in the plate, the boss protrudes from the inner wall of the conductive hole, and a second isolation sleeve is sandwiched between the boss and the base.

[0075] In some embodiments of this application, the height of the boss is H2, where 1mm ≤ H2 ≤ 5mm.

[0076] In some embodiments of this application, the height of the boss is H2, the thickness of the first conductive element is L11, and 40% ≤ H2 / L11 ≤ 60%.

[0077] In some embodiments of this application, the height of the boss is H2, the thickness of the first conductive element is L11, the natural length of the second insulating sleeve is L12, and H2+L12≥L11.

[0078] In some embodiments of this application, the second isolation sleeve includes a ring portion and a gasket portion, the ring portion being at least partially inserted into the conductive hole, and the gasket portion being at least partially clamped by the base and the first conductive element.

[0079] In some embodiments of this application, the outer diameter of the gasket portion is D10, the outer diameter of the base is D12, and 70% ≤ D12 / D10 ≤ 120%.

[0080] In some embodiments of this application, the thickness of the gasket portion is L13, where 0.5 ≤ L13 ≤ 1.5 mm.

[0081] In some embodiments of this application, the first conductive element is further formed with a pressure relief groove, which is recessed on the surface of the first conductive element to avoid the conductive hole.

[0082] In some embodiments of this application, the distance between the edge of the pressure relief groove and the edge of the electrical conductivity hole is L15, where 2mm < L15 < 35mm.

[0083] In some embodiments of this application, the maximum width of the pressure relief groove is L16, where 0.05mm≤L16≤5mm.

[0084] In some embodiments of this application, the first conductive element includes a first surface and a second surface disposed opposite to each other, the first surface being oriented toward the cell assembly, and a pressure relief groove being formed on the second surface.

[0085] In some embodiments of this application, the distance between the bottom of the pressure relief groove and the first surface is L17, where 0.02mm≤L17≤1.5mm.

[0086] In some embodiments of this application, the included angle between the pressure relief groove and the two groove walls is A4, where 20°≤A4≤90°.

[0087] In some embodiments of this application, the pressure relief groove has a trapezoidal cross-section perpendicular to its extension direction, and the lower base of the trapezoid is located on the surface of the first conductive element.

[0088] In some embodiments of this application, the length of the upper base of the trapezoid is L18, where 0.02mm≤L18≤3mm.

[0089] In some embodiments of this application, the bottom of the pressure relief groove has rounded corners.

[0090] In some embodiments of this application, the radius of the fillet is R1, the maximum width of the pressure relief groove is L16, and 20% ≤ R1 / L16 ≤ 100%.

[0091] In some embodiments of this application, the single cell further includes a fourth insulating layer covering the surface of the first conductive element facing the cell assembly.

[0092] In some embodiments of this application, the fourth isolation layer is either a nickel plating layer or an iron alloy plating layer.

[0093] In some embodiments of this application, the fourth isolation layer is either a PP film or PPS.

[0094] In some embodiments of this application, the area of ​​the first conductive element near the cell assembly is S1, and the projected area of ​​the fourth insulating layer on the surface of the first conductive element is S8, where 5% ≤ S8 / S1 ≤ 97%.

[0095] In some embodiments of this application, the thickness of the fourth isolation layer is L19, where 0.05mm≤L19≤2mm.

[0096] In some embodiments of this application, the thickness of the fourth insulating layer is uniformly distributed across the entire surface of the first conductive element.

[0097] In some embodiments of this application, the thickness of the fourth isolation layer increases as it approaches the conductive hole.

[0098] In some embodiments of this application, the thickness of the first conductive element is L11, where 0.5mm ≤ L11 ≤ 2mm.

[0099] In some embodiments of this application, the single battery cell also includes a casing with an opening on one side. A first conductive element blocks the opening of the casing, and the casing together forms an accommodating space. The battery cell assembly is disposed within the accommodating space.

[0100] In some embodiments of this application, the single cell further includes a second weld, through which the first conductive element and the casing are connected.

[0101] In some embodiments of this application, the height of the second weld protruding from the surface of the housing is H3, where 0mm≤H3≤3mm.

[0102] In some embodiments of this application, the width of the second weld is L20, where 2mm ≤ L20 ≤ 6mm.

[0103] In some embodiments of this application, the first conductive element includes a first plate, a second plate, and a third plate. A conductive hole is formed in the first plate, the third plate is wrapped around the first plate, the housing is connected to the third plate, and the opposite ends of the second plate are respectively connected to the first plate and the third plate. The first plate and the second plate are embedded in the opening of the housing.

[0104] In some embodiments of this application, the first plate and the second plate are connected by an arc.

[0105] In some embodiments of this application, the radius of the arc is R2, where 0.1mm ≤ R2 ≤ 2mm.

[0106] In some embodiments of this application, the radius of the arc is R2, the thickness of the first plate is L21, and 20% ≤ R2 / L21 ≤ 100%.

[0107] In some embodiments of this application, there is an assembly gap between the second plate and the housing.

[0108] In some embodiments of this application, the width of the assembly gap is L22, where 0.1mm≤L22≤0.5mm.

[0109] The beneficial effects of this utility model are as follows:

[0110] The second conductive element passes through the conductive hole on the first conductive element, and the second conductive element and the first conductive element are physically connected and simultaneously conductive. The second conductive element is welded to the battery cell assembly. Compared with the prior art, the material selection of the second conductive element in this application is less restricted by structural strength. Therefore, the first conductive element and the second conductive element in this application can be configured with different materials. For example, the first conductive element can be configured with an aluminum alloy structure commonly used in existing top cover assemblies to ensure the strength of the single battery cell casing; the second conductive element can be configured with the same material as the busbar of the battery cell assembly, so that the welding of the second conductive element and the busbar of the battery cell assembly is homogeneous welding, resulting in better weld quality. Attached Figure Description

[0111] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0112] Figure 1 This is a schematic diagram of the overall structure of a single battery provided in an embodiment of this utility model;

[0113] Figure 2 This is an overall cross-sectional view of a single battery provided in an embodiment of this utility model;

[0114] Figure 3 yes Figure 2 A magnified view of a portion of region A in the middle;

[0115] Figure 4 This is a schematic diagram of the cooperation between the second conductive element and the battery cell assembly provided in another embodiment of the present invention;

[0116] Figure 5 This is a schematic diagram of the cooperation between the second conductive element and the first insulating layer provided in this embodiment of the utility model;

[0117] Figure 6This is a schematic diagram of the cooperation between the first conductive element and the second conductive element provided in this embodiment of the utility model;

[0118] Figure 7 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the first isolation sleeve according to another embodiment of the present invention;

[0119] Figure 8 This is an overall cross-sectional view of a single battery provided in another embodiment of this utility model;

[0120] Figure 9 yes Figure 8 A magnified view of a portion of region B in the middle;

[0121] Figure 10 yes Figure 9 A magnified view of a portion of region C in the middle;

[0122] Figure 11 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the fastener provided in another embodiment of this utility model;

[0123] Figure 12 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the fastener provided in another embodiment of this utility model;

[0124] Figure 13 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, the fastener, and the second isolation sleeve provided in another embodiment of this utility model;

[0125] Figure 14 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, the fastener, and the second isolation sleeve provided in another embodiment of this utility model;

[0126] Figure 15 This is an overall cross-sectional view of a single battery provided in another embodiment of this utility model;

[0127] Figure 16 yes Figure 15 A magnified view of a portion of region D in the middle;

[0128] Figure 17 This is a schematic diagram of the cooperation between the first conductive element and the second conductive element provided in another embodiment of this utility model;

[0129] Figure 18 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the second isolation sleeve provided in another embodiment of this utility model;

[0130] Figure 19 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the second isolation sleeve provided in another embodiment of this utility model;

[0131] Figure 20yes Figure 2 A magnified view of a portion of region E in the middle;

[0132] Figure 21 This is a schematic diagram of the cooperation between the pressure relief groove and the second conductive component provided in another embodiment of this utility model;

[0133] Figure 22 This is a schematic diagram of the cooperation between the pressure relief groove and the second conductive component provided in another embodiment of this utility model;

[0134] Figure 23 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the fourth insulating layer provided in this embodiment of the utility model;

[0135] Figure 24 This is a schematic diagram showing the cooperation of the first conductive element, the second conductive element, and the fourth insulating layer according to another embodiment of the present invention;

[0136] Figure 25 This is a schematic diagram showing the connection relationship between the first conductive element and the housing provided in this embodiment of the utility model.

[0137] Explanation of icon numbers:

[0138] 10. First conductive element; 11. Plate body; 111. Conductive hole; 112. Second hole; 113. Third hole; 114. Pressure relief groove; 12. Boss; 13. First plate; 14. Second plate; 15. Third plate; 20. Second conductive element; 21. Welding hole; 22. Rivet post; 23. Rivet seat; 24. Rivet buckle; 241. Outer chamfer; 242. Riveting hole; 243. Inner chamfer; 25. Through post; 26. Edge retainer; 261. First hole; 27. Connecting rod; 28. Bottom 29. Socket; 30. Buckle; 31. Battery cell assembly; 31. Battery cell; 311. Core; 312. Electrode; 32. Busbar; 41. First weld; 42. Second weld; 51. First isolation layer; 52. Second isolation layer; 53. Third isolation layer; 54. Fourth isolation layer; 55. First isolation sleeve; 56. Second isolation sleeve; 561. Ring part; 562. Gasket part; 60. Fastener; 61. First part; 62. Second part; 70. Housing; 80. Assembly gap. Detailed Implementation

[0139] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0140] To address the technical problems of complex welding parameters and poor weld quality between the casing and cell assembly 30 of a single battery cell, this utility model provides a single battery cell comprising a first conductive element 10, a second conductive element 20, and a cell assembly 30.

[0141] Please see Figures 1 to 3 As shown, Figure 1 This is a schematic diagram of the overall structure of a single battery provided in an embodiment of this utility model; Figure 2 This is an overall cross-sectional view of a single battery provided in an embodiment of this utility model;

[0142] Figure 3 yes Figure 2 The enlarged view of region A in the middle, together with the above figures, shows the cooperation relationship between the first conductive element 10, the second conductive element 20 and the battery cell 31.

[0143] Specifically, the first conductive element 10 has a conductive hole 111, which penetrates the first conductive element 10 in the thickness direction; the second conductive element 20 passes through the conductive hole 111, and is fixed and electrically connected to the first conductive element 10; the battery cell assembly 30 is welded to the second conductive element 20.

[0144] In this embodiment, the second conductive element 20 passes through the conductive hole 111. The first conductive element 10 and the second conductive element 20 are fixed to each other and electrically connected. Due to the separate design of the first conductive element 10 and the second conductive element 20, they can be configured with different materials according to requirements. For example, the second conductive element 20 is configured with the same material as the area of ​​the cell assembly 30 to which it is welded, which optimizes the weld performance between the second conductive element 20 and the cell assembly 30. At the same time, since the area of ​​the second conductive element 20 on the entire shell is small, the material adjustment of the second conductive element 20 will not have a significant impact on the structural performance of the single battery shell.

[0145] Compared with the prior art, since the second conductive element 20 can be configured as needed to adapt to the cell assembly 30, the single cell of this embodiment can significantly optimize the weldability between the casing and the cell assembly 30 without significantly affecting the strength of the single cell casing. It is no longer necessary to configure complex welding parameters for dissimilar metals on both sides. This improves the weld strength and conductivity, simplifies the production process, optimizes the performance of the single cell, and extends the service life of the single cell.

[0146] In some embodiments of this application, a welding hole 21 is also formed on the second conductive element 20, and the opening direction of the welding hole 21 is towards the side of the second conductive element 20 away from the cell assembly 30.

[0147] For clarity, the processing steps of a single battery cell are explained here. Typically, during the processing of a single battery cell, in order to weld the casing and the cell assembly 30, the conductive area of ​​the cell assembly 30 is brought into contact with the casing from the inside. Then, the welding torch is aimed at the corresponding area on the outside of the casing, and by applying voltage and high temperature, the conductive area of ​​the cell assembly 30 that is in contact with the casing is melted through the casing. The molten metal solidifies to form a weld.

[0148] Because the welding process requires melting through the outer shell, the thickness of the outer shell determines the power requirement and penetration of the weld. In this embodiment, the second conductive element 20 is welded to the cell assembly 30. Therefore, the smaller the distance between the outer and inner surfaces of the welding area of ​​the second conductive element 20, the easier the welding will be. By opening welding holes 21 on the second conductive element 20, the welding torch can be brought closer to the area where the cell assembly 30 and the second conductive element 20 are connected. This reduces energy loss during transmission and prevents overheating of the second conductive element 20 during welding, effectively ensuring that the second conductive element 20 retains good electrical and mechanical properties after welding.

[0149] Furthermore, the diameter of the electrical conductivity hole 111 is D1, and the diameter of the welding hole 21 is D2, with 30% ≤ D2 / D1 ≤ 90%.

[0150] The diameter of the welding hole 21 is limited by the diameter of the electrical conductivity hole 111. A larger welding hole 21 allows a larger welding torch to be inserted into it for welding. However, given a fixed size for the electrical conductivity hole 111, an excessively large welding hole 21 would result in an excessively thin wall thickness at the location of the welding hole 21 in the second conductive component 20, affecting the strength and current-carrying capacity of the second conductive component 20. A value of 30% ≤ D2 / D1 ≤ 90% allows for easier insertion of the welding torch into the welding hole 21 while ensuring the strength and current-carrying capacity of the second conductive component 20.

[0151] Optionally, the depth of the welding hole 21 is L1, and the projected length of the second conductive element 20 in the thickness direction of the first conductive element 10 is L2, where 50% ≤ L1 / L2 ≤ 90%.

[0152] The depth of the welding hole 21 is limited by the second conductive element 20. If the welding hole 21 is too shallow, the welding current or heat energy needs to penetrate the thicker bottom of the second conductive element 20, wasting energy and damaging the crystal structure of the second conductive element 20. If the welding hole 21 is too deep, the bottom of the second conductive element 20 will be too thin, posing a risk of excessively rapid heating or even burn-through during the welding process. A value of 50% ≤ L1 / L2 ≤ 90% can ensure that the thickness of the bottom of the second conductive element 20 is suitable for the welding step.

[0153] It should be noted that the thickness direction mentioned in this embodiment does not necessarily mean that the dimension of the first conductive element 10 in this direction is smaller than its diameter. The description here only indicates that in most existing single-cell batteries, the thickness direction is unambiguously represented by the direction in which the first conductive element 10 is fastened to the housing 70. All dimensional descriptions mentioned below are merely general descriptions in this technical field without additional limitations, and do not imply the absence of special cases. Their specific references should be based on the markings in the corresponding drawings.

[0154] Optionally, the minimum distance between the wall of the welding hole 21 and the outer wall of the second conductive element 20 is L3, where L3 ≥ 0.05 mm.

[0155] The welding hole 21 is preferably coaxially arranged with the second conductive element 20. However, considering the processing accuracy and assembly clearance, there are also application scenarios where the two are eccentrically arranged. Limiting L3 to ≥ 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 element 20 from being too close, thus avoiding the second conductive element 20 from being broken down due to insufficient current carrying capacity during the subsequent use of the single cell.

[0156] Optionally, the distance between the bottom of the welding hole 21 and the surface of the second conductive element 20 near the cell assembly 30 is L4, where 0.05mm≤L4≤2mm.

[0157] The dimensions of the second conductive element 20 vary depending on the capacity and design of the individual battery cell. However, the thickness of the bottom of the second conductive element 20, which 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 element 20 closest to the cell assembly 30—is limited by the welding process and has a specific range of parameters. This range does not change significantly with variations in the second conductive element 20. Calculations show that a value range of 0.05mm ≤ L4 ≤ 2mm is optimal. This range avoids the bottom of the excessively thin second conductive element 20 being burned through, while also preventing energy waste due to an excessively thick bottom.

[0158] In some embodiments of this application, the battery cell assembly 30 includes a battery cell 31 and a busbar 32, the busbar 32 being electrically connected to the battery cell 31 and the second conductive element 20, respectively.

[0159] The busbar 32 can collect the current of the entire cell 31. The second conductive element 20 is welded to the busbar 32. The current of the cell 31 is conducted to the first conductive element 10 through the busbar 32 and the second conductive element 20. During the entire current transmission process, the original largest resistance section is greatly optimized because the second conductive element 20 and the busbar 32 are welded together, which improves the energy efficiency of the single cell.

[0160] Furthermore, the area of ​​the first conductive element 10 near the cell assembly 30 is S1, and the projected area of ​​the contact surface between the second conductive element 20 and the busbar 32 on the first conductive element 10 is S2, where 20% ≤ S2 / S1 ≤ 90%.

[0161] The larger the contact area between the second conductive element 20 and the busbar 32, the stronger the current conduction capacity between them. However, this positive correlation has a limit due to the area of ​​the busbar 32. 20% ≤ S2 / S1 ≤ 90% is a numerical range from which a more intuitive performance optimization can be obtained by increasing the area of ​​the busbar 32 and the second conductive element 20.

[0162] It should be noted that the projected area here refers to the area of ​​the largest shape that the structure can enclose on the corresponding plane. For structures with internal holes, the projected area should be defined by the outer edge of the projected shape.

[0163] Optionally, the second conductive element 20 is connected to the busbar 32 via a first weld 41. The projected area of ​​the first weld 41 on the surface of the busbar 32 is S3, and the surface area of ​​the busbar 32 on the side closer to the structure of the first conductive element 10 is S4, where S3 / S4≥10%.

[0164] The larger the proportion of the first weld 41, the more stable the connection between the busbar 32 and the second conductive element 20. Especially in technical solutions that require stabilizing the position of the cell assembly 30 through the first weld 41, the cross-sectional area of ​​the first weld 41 directly affects whether the cell assembly 30 can maintain its connection with the second conductive element 20. S3 / S4≥10% is the preferred numerical range for maintaining the connection between the second conductive element 20 and the busbar 32.

[0165] Optionally, the second conductive element 20 is welded to the side of the busbar 32 closest to the first conductive element 10, and the side of the busbar 32 furthest from the second conductive element 20 is electrically connected to the battery cell 31.

[0166] The two sides of the busbar 32 are electrically connected to the second conductive element 20 and the battery cell 31, respectively, which can make full use of the surface area of ​​the busbar 32 to increase the current-carrying area and current-carrying capacity.

[0167] Optionally, the second conductive element 20 and the busbar 32 are made of the same material.

[0168] The second conductive component 20 and the busbar 32, which are made of the same material, are similar in welding parameters and flowability, and the effect of homogeneous welding is better.

[0169] Please refer to the following: Figure 4 As shown, Figure 4 This is a schematic diagram of the cooperation between the second conductive element and the battery cell assembly provided in another embodiment of this utility model.

[0170] In some embodiments of this application, the battery cell assembly 30 includes an electrically connected core 311 and a tab 312, with the tab 312 welded to a second conductive element 20.

[0171] This embodiment provides another technical solution. In some technical solutions that do not include the busbar 32, the second conductive element 20 can also be directly electrically connected to the battery cell 31. Specifically, the battery cell 31 includes a core 311 and a tab 312, and the second conductive element 20 and the tab 312 are welded together.

[0172] Furthermore, the second conductive element 20 and the tab 312 are made of the same material.

[0173] Similar to the busbar 32, the second conductive element 20 and the tab 312, which are made of the same material, have similar welding parameters and flowability, resulting in better homogeneous welding.

[0174] In some embodiments of this application, there are multiple conductive holes 111, and the second conductive element 20 is provided in correspondence with each conductive hole 111.

[0175] Multiple conductive holes 111 can disperse the current-carrying area, resulting in better current-carrying performance while keeping the total current-carrying area constant.

[0176] Furthermore, a plurality of conductive holes 111 are arranged in a circumferential array on the first conductive element 10.

[0177] On the one hand, the conductive holes 111 in the circular array can make the current distribution more uniform and optimize the electrical performance of the single cell. On the other hand, the conductive holes 111 in the circular array can also minimize the damage to the mechanical performance of the single cell caused by the opening on the first conductive element 10.

[0178] In some embodiments of this application, the material of the second conductive element 20 is copper.

[0179] The existing battery cell assembly 30, whether it is the type that outputs directly to the outside through the tab 312 or the type that outputs after being combined through the busbar 32, is mostly made of copper at the output end. The material configuration of the second conductive element 20 as copper can enhance the welding compatibility between the second conductive element 20 and the battery cell assembly 30, simplify the welding process, and optimize the weld performance.

[0180] It should be noted that in this embodiment, the busbar 32 and the tab 312 are described as output terminals. In a considerable number of cell assemblies 30, the busbar 32 and the tab 312 simultaneously serve as current input terminals. The description here only indicates that the busbar 32 and the tab 312 serve as output terminals during the use of a single battery cell, and does not limit them to only output. This should not be used to limit the scope of protection of this application. The output of the following embodiments should also be understood in this way.

[0181] Please refer to the following: Figure 5 As shown, Figure 5 This is a schematic diagram of the cooperation between the second conductive element and the first insulating layer provided in an embodiment of this utility model.

[0182] Furthermore, the single cell also includes a first insulating layer 51, which encloses a second conductive element 20, with at least a partial exposure of the side of the second conductive element 20 closest to the cell assembly 30.

[0183] In actual processing, the second conductive element 20 and the cell assembly 30 only partially come into contact and are welded. Therefore, with the welded area exposed, setting a first insulating layer 51 to protect other areas of the second conductive element 20 is an effective way to extend its service life. During actual single-cell operation, because the first conductive element 10 and the second conductive element 20 are dissimilar metals, their connection area immersed in the electrolyte will experience electrochemical corrosion. Using the first insulating layer 51 to isolate the first conductive element 10 and the second conductive element 20 can effectively slow down the corrosion rate at their joint.

[0184] Furthermore, the first insulating layer 51 is made of at least one of steel and nickel.

[0185] On the one hand, steel and nickel are both commonly used materials for the first conductive element 10, so electrochemical corrosion is unlikely to occur between the first insulating layer 51 and the first conductive element 10 in direct contact; on the other hand, the joint between the first insulating layer 51 and the second conductive element 20 is sealed between the second conductive element 20 and the battery cell assembly 30, making it difficult for electrolyte to enter and creating an environment conducive to electrochemical corrosion, thus making it difficult for electrochemical corrosion to occur.

[0186] Optionally, the area of ​​the exposed portion of the second conductive member 20 on the side near the cell assembly 30 is S5, and the area of ​​the first conductive member 10 on the side near the cell assembly 30 is S1, where 40% ≤ S5 / S1 ≤ 100%.

[0187] Sufficient exposed area of ​​the second conductive element 20 is a prerequisite for ensuring good weldability and current carrying capacity between the second conductive element 20 and the 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%.

[0188] Please refer to the following: Figure 6 As shown, Figure 6 This is a schematic diagram of the cooperation between the first conductive element and the second conductive element provided in the embodiment of this utility model.

[0189] In some embodiments of this application, the second conductive element 20 and the first conductive element 10 are riveted together.

[0190] Riveting is a commonly used processing technique. That is, a riveting machine is used to deform and expand the second conductive element 20 that passes through the electrical conductive hole 111 and lock it at the edge of the electrical conductive hole 111. The riveting and fixing of the second conductive element 20 and the first conductive element 10 can achieve a good connection effect between the first conductive element 10 and the second conductive element 20 while having a high productivity.

[0191] Furthermore, the first conductive element 10 includes a first surface and a second surface opposite to each other, and the second conductive element 20 includes a rivet seat 23, a rivet post 22 and a rivet buckle 24 connected in sequence. Specifically, the rivet post 22 has a conductive hole 111 passing through it; the rivet seat 23 is connected to one end of the rivet post 22 and abuts against the first surface; the rivet buckle 24 is connected to the end of the rivet post 22 away from the rivet seat 23 and is riveted to the second surface.

[0192] The rivet base 23 abuts against the first surface, and the rivet 24 abuts against the second surface. The formation of the rivet 24 depends on the deformation brought about by the riveting machine. The length of the rivet post 22 depends on the amount of deformation of the rivet post 24 during the riveting process. Therefore, the rivet post 22 can adapt to the thickness of the first conductive element 10, so that the rivet base 23 and the rivet post 24 can clamp the first conductive element 10 well.

[0193] Furthermore, the outer edge of the end of the rivet 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 24, the angle between the outer chamfer 241 and the second surface is A1, where 10°≤A1≤85°.

[0194] The outer chamfer 241 effectively prevents scratch damage between the rivet 24 and other components. An excessively large A1 will lead to the formation of new protrusions, rendering the outer chamfer 241 meaningless. Conversely, an excessively small A1 will require the rivet 24 to extend outwards a greater distance to accommodate its thickness. A value between 10° ≤ A1 ≤ 85° is beneficial for structural design and compatible with existing riveting machines. Preferred values ​​for A1 are 45°, 48°, or 54°.

[0195] Specifically, the distance between the outer edge of the outer chamfer 241 and the second surface is L5, the thickness of the rivet 24 is L6, and 0≤L5 / L6≤70%.

[0196] If the distance between the outer edge of the outer chamfer 241 and the second surface is too thick, it will affect the appearance of the individual cells and increase the risk of damage caused by collisions between individual cells in the battery pack. 0≤L5 / L6≤70% is a better value choice, and the most preferred value for L5 / L6 is 0%, that is, the outer edge of the outer chamfer 241 is directly attached to the surface of the first conductive element 10.

[0197] Optionally, the thickness of the rivet 24 is L6, and the projected length of the second conductive element 20 in the thickness direction of the rivet 24 is L7, where 10% ≤ L6 / L7 ≤ 40%.

[0198] Although the thickness of the rivet 24 varies depending on the thickness of the material it is riveted to, the thickness of the rivet 24 itself still has some reference value. If the rivet 24 is too small, there is a risk that the rivet 24 will fall off the rivet post 22, resulting in the failure of the connection between the first conductive element 10 and the second conductive element 20. On the other hand, if the rivet 24 is too large, it indicates that there is a defect in the riveting size selection, resulting in a large waste of materials and increasing the redundant weight of the single battery. 10% ≤ L6 / L7 ≤ 40% can ensure the connection effect of the first conductive element 10 and the second conductive element 20 while saving materials as much as possible. The preferred values ​​for L6 / L7 are 20%, 23%, and 25%.

[0199] Optionally, the diameter of the electrical conductivity hole 111 is D1, and the outer diameter of the rivet 24 is D3, where 120% ≤ D3 / D1 ≤ 200%.

[0200] The outer diameter of the rivet 24 determines the riveting strength. Given a fixed size for the electrical conductive hole 111, a larger outer diameter of the rivet 24 results in a better riveting effect. However, an excessively large rivet 24 will lead to space occupation and material waste. A ratio of 120% ≤ D3 / D1 ≤ 200% is chosen to save material as much as possible while ensuring riveting strength. Provided the machining accuracy allows, D3 / D1 is preferably 128% or 130%.

[0201] Optionally, the diameter of the rivet 23 is D4, where 2mm≤D4≤20mm.

[0202] The diameter of the rivet base 23 determines the pressure-bearing capacity of the second conductive component 20 during the riveting process. This is not affected by the conductive hole 111. An excessively large rivet base 23 will undoubtedly occupy extra space. Therefore, 2mm≤D4≤20mm can avoid damage to the rivet base 23 during the riveting process while saving space as much as possible. D4 is preferably 4mm, 6mm, or 8mm.

[0203] Optionally, the diameter of the electrical conductivity hole 111 is D1, and the diameter of the rivet seat 23 is D4, where 130% ≤ D4 / D1 ≤ 200%.

[0204] The selection of the rivet base 23 should also refer to the electrical conductive hole 111. If the size of the rivet base 23 is too small, there is a risk that the rivet base 23 will be directly inserted into the electrical conductive hole 111 with an interference fit. If the size of the rivet base 23 is too large, it will result in the occupation of extra space. 130%≤D4 / D1≤200% is the preferred solution. Under the premise that the machining accuracy allows, D4 / D1 is preferably 130%, 132%, or 135%.

[0205] Optionally, the thickness of the rivet base 23 is L8, where 0.05mm≤L8≤2mm.

[0206] The thickness of the rivet base 23 also affects the load-bearing capacity during the riveting process. A rivet base 23 that is too thin is prone to breakage during riveting, while a rivet base 23 that is too large will occupy extra space. Therefore, 0.05mm≤L8≤2mm can avoid damage to the rivet base 23 during riveting while saving space as much as possible. The preferred values ​​for L8 are 0.1mm, 0.5mm, and 1mm.

[0207] Please refer to the following: Figure 7 As shown, Figure 7 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, and the first isolation sleeve 55 provided in another embodiment of this utility model.

[0208] Optionally, the single cell also includes a first isolation sleeve 55, a rivet post 22 passing through the first isolation sleeve 55, and a rivet base 23 and the first surface clamping the first isolation sleeve 55.

[0209] The first isolation sleeve 55 separates the rivet base 23 and the first surface, preventing electrochemical corrosion caused by the first conductive component 10 and the second conductive component 20 being immersed in the electrolyte and in direct contact. In addition, the first isolation sleeve 55 is sandwiched between the rivet base 23 and the first surface. During the riveting process, the first isolation sleeve 55 will undergo slight deformation to adapt to the rivet base 23 and the first surface, which can effectively increase the airtightness at the electrical conductivity hole 111.

[0210] Specifically, the diameter of the rivet seat 23 is D4, and the outer diameter of the first isolation sleeve 55 is D5, with 70% ≤ D4 / D5 ≤ 120%.

[0211] The diameter of the rivet 23 should be as close as possible to the outer diameter of the first separator 55. A large difference in size will create redundant structures, affecting the space utilization of individual cells and increasing additional production costs. 70% ≤ D4 / D5 ≤ 120%. Provided the machining accuracy allows, D4 / D5 can be selected as 95%, 98%, or 100%. D4 ≤ D5 can avoid electrochemical corrosion caused by the rivet 23 and the first separator facing each other directly.

[0212] Specifically, the thickness of the first isolation sleeve 55 is L9, 0.5≤L9≤1.5mm.

[0213] The thickness of the first insulating sleeve 55 is an important parameter affecting its insulation and sealing performance. If the first insulating sleeve 55 is too thin, it cannot seal well and is easily squeezed and damaged during riveting. If the first insulating sleeve 55 is too thick, it will take up extra space and affect the space utilization rate of the single cell.

[0214] In some embodiments of this application, a riveting hole 242 is also formed on the riveted second conductive member 20, and the opening direction of the riveting hole 242 is towards the side of the second conductive member 20 away from the cell assembly 30.

[0215] The setting of the riveting hole 242 is conducive to the insertion of the riveting machine punch and also to the rivet 24 rolling around, reducing the risk of the second conductive component 20 being damaged due to the riveting process.

[0216] Furthermore, the edge of the rivet hole 242 is provided with an inner chamfer 243. On any cross section passing through the axis of the rivet hole 242, the angle between the plane of the inner chamfer 243 and the second surface is A2, 30°≤A2≤85°.

[0217] The setting of the inner chamfer 243 is beneficial to guide the riveting punch and the riveting hole 242 to align. If A2 is too large, the outer edge of the inner chamfer 243 will be too narrow, resulting in insufficient guiding effect. If A2 is too small, the punch and the inner chamfer 243 will collide and cannot be guided. 30°≤A2≤85° can ensure a good guiding effect. The optimal values ​​for A2 are 40°, 45°, and 48°.

[0218] Optionally, the diameter of the rivet hole 242 is D6, and the minimum outer diameter of the second conductive element 20 is D7, with 30% ≤ D6 / D7 ≤ 80%.

[0219] The diameter of the riveting hole 242 is limited by the outer diameter of the second conductive component 20. A larger riveting hole 242 results in a thinner hole wall, making the riveting process easier. However, an excessively large riveting hole 242 will result in an excessively thin wall thickness at the location of the riveting hole in the second conductive component 20, affecting its strength and current-carrying capacity. A value selection of 30% ≤ D6 / D7 ≤ 80% can ensure the strength and current-carrying capacity of the second conductive component 20 while facilitating the riveting process as much as possible. The optimal values ​​for D6 / D7 are 40% or 50%.

[0220] Please refer to the following: Figure 8 and Figure 9 As shown, Figure 8 This is an overall cross-sectional view of a single battery provided in another embodiment of this utility model; Figure 9 yes Figure 8 A magnified view of a portion of region B in the middle.

[0221] In some embodiments of this application, the single cell also includes a fastener 60, and the second conductive element 20 includes a through post 25 and a stop 26. The through post 25 passes through the conductive hole 111, and the stop 26 abuts against the first conductive element 10. The fastener 60 passes through at least one of the first conductive element 10 and the second conductive element 20 and realizes the connection between the first conductive element 10 and the second conductive element 20.

[0222] Unlike riveting, in this embodiment, the second conductive element 20 only needs to abut against one side surface of the first conductive element 10, making assembly more flexible and facilitating the design of the structure on the other side of the first conductive element 10 opposite to the abutment point.

[0223] Furthermore, a first hole 261 is provided on the retaining edge 26, and the fastener 60 passes through the first hole 261 and is connected to the first conductive element 10.

[0224] The fastener 60 is connected to the first conductive element 10 on one hand, and the fastener 60 passes through the first hole 261 on the other hand. With the fastener 60 fixed, the first conductive element 10 and the second conductive element 20 are tightened, which optimizes the connection effect and airtightness of the first conductive element 10 and the second conductive element 20.

[0225] Please refer to the following: Figure 10 As shown, Figure 10 yes Figure 9 A magnified view of a portion of region C.

[0226] Furthermore, a second insulating layer 52 is provided between the first conductive element 10 and the second conductive element 20.

[0227] The second isolation layer 52 isolates the first conductive element 10 and the second conductive element 20 at least partially, thus avoiding electrochemical corrosion caused by direct exposure of the first conductive element 10 and the second conductive element 20.

[0228] Specifically, the second isolation layer 52 is at least one of PP film or PPS film.

[0229] PP film and PPS film are relatively mature protective materials in the field of lithium batteries, with low cost and high processing efficiency.

[0230] Optionally, the surface of the fastener 60 that contacts the first conductive element 10 and the second conductive element 20 is provided with a third insulating layer 53.

[0231] The third isolation layer 53 protects the fastener 60, preventing it from wearing out during the fastening process and affecting its fastening effect.

[0232] Specifically, the third isolation layer 53 is a nickel plating layer.

[0233] The nickel plating can provide protection while also ensuring conductivity, which is especially beneficial for the full-coverage protection of the first conductive component 10.

[0234] Optionally, the distance between the surface of the through post 25 near the cell assembly 30 and the surface of the first conductive element 10 near the cell assembly 30 is H1, where 0.8≤H1≤2mm.

[0235] The distance between the surface of the through-post 25 near the cell assembly 30 and the surface of the first conductive element 10 near the cell assembly 30, i.e., the height of the through-post 25 protruding from the first conductive surface, is crucial. If H1 is too large, it will result in a large gap between the cell assembly 30 and the first conductive element 10; if H2 is too small, it will pose a risk of short circuit between the first conductive element 10 and the cell assembly 30, affecting the safety of the individual battery. A distance of 0.8 ≤ H1 ≤ 2 mm can maximize the space utilization within the individual battery while ensuring safety. Where production precision allows, H1 is preferably 8 mm, 9 mm, or 10 mm.

[0236] Optionally, the projected area of ​​the outer edge of the stop 26 on the first conductive element 10 is S6, and the contact area between the stop 26 and the first conductive element 10 is S7, where 5% ≤ S7 / S6 ≤ 35%.

[0237] The contact area between the retaining edge 26 and the first conductive element 10 affects the connection strength and current carrying capacity of the first conductive element 10 and the second conductive element 20. 5% ≤ S7 / S6 ≤ 35% can enhance the connection strength and current carrying capacity of the first conductive element 10 and the second conductive element 20 as much as possible under the premise that the size of the second conductive element 20 is fixed. S7 / S6 is preferably 20% and 30%.

[0238] Please refer to the following: Figure 11 As shown, Figure 11 This is a schematic diagram of the cooperation between the first conductive element 10, the second conductive element 20, and the fastener 60 provided in another embodiment of this utility model.

[0239] Optionally, there may be multiple first holes 261 on each flange 26.

[0240] Multiple first holes 261 can distribute the load, resulting in better fixing effect without changing the total cross-sectional area of ​​the fastener 60.

[0241] Furthermore, multiple first holes 261 are distributed in a circumferential array on the retaining edge 26.

[0242] On the one hand, the first hole 261 in the circumferential array can make the force of the fastener 60 more uniform and enhance the connection strength between the first conductive element 10 and the second conductive element 20. On the other hand, the first hole 261 distributed in the circumferential array can also minimize the damage to the mechanical properties of the second conductive element 20 caused by the hole in the flange 26.

[0243] Optionally, the retaining edge 26 abuts against the side of the first conductive member 10 away from the cell assembly 30.

[0244] The flange 26 of the second conductive element 20 abuts against the side of the first conductive element 10 away from the cell assembly 30. That is, the second conductive element 20 is inserted from the outside of the single cell and can be installed last after the first conductive element 10, cell assembly 30 and other structures are assembled. The second conductive element 20 abuts against the cell assembly 30 at the same time as it is inserted and connected to the first conductive element 10.

[0245] Optionally, the diameter of the first hole 261 is D8, where 2.5mm ≤ D8 ≤ 16mm.

[0246] The diameter of the first hole 261 should be set to fit the fastener 60. 2.5mm≤D8≤16mm can fit fasteners 60 of commonly used sizes. The preferred diameters of the first hole 261 are 2.5mm and 16mm.

[0247] Optionally, the first conductive element 10 is provided with a second hole 112, and the fastener 60 passes through the first hole 261 and is inserted into the second hole 112.

[0248] The perforation on the edge 26 will not affect the airtightness of the individual battery. The fastener 60 passes through the first hole 261 and is inserted into the second hole 112, which can achieve connection while having almost no impact on the airtightness of the individual battery.

[0249] Specifically, fastener 60 is a screw, and fastener 60 is threaded into the second hole 112.

[0250] Fastener 60 is optional, consisting of screws. The parts are low-cost, the production line technology is mature, and the production efficiency is high.

[0251] Please refer to the following: Figure 12 As shown, Figure 12 This is a schematic diagram of the cooperation between the first conductive element 10, the second conductive element 20, and the fastener 60 provided in another embodiment of this utility model.

[0252] Optionally, the fastener 60 includes a first part 61 and a second part 62 connected to each other. The first part 61 passes through the first hole 261 or the third hole 113, and the second part 62 abuts against the side of the second conductive member 20 away from the first conductive member 10, or the second part 62 abuts against the side of the first conductive member 10 away from the second conductive member 20.

[0253] The second part 62 abuts against the first conductive element 10 or the second conductive element 20. When the fastener 60 is removed, the abutment surface still maintains its original structure, reducing damage to the parts.

[0254] Specifically, the diameter of the first part 61 is D9, and 2.5mm≤D9≤16mm.

[0255] For the first part 61, under the premise of meeting the strength requirements, selecting a common part size range of 2.5mm≤D9≤16mm can reduce production costs. D9 is preferably 2.5mm and 16mm.

[0256] Specifically, the thickness of the second part 62 is L10, 0.5mm≤L10≤2mm.

[0257] The thickness of the second part 62 affects its load-bearing capacity during the fastening process. If the second part 62 is too thin, it is prone to breakage during the fastening process, while if the second part 62 is too large, it will occupy extra space. Therefore, 0.5mm≤L10≤2mm can avoid damage to the second part 62 during the fastening process while saving space as much as possible. L10 is preferably 0.5mm and 1mm.

[0258] In some embodiments of this application, a third hole 113 is provided on the first conductive element 10, and the fastener 60 passes through the third hole 113 and is connected to the second conductive element 20.

[0259] This embodiment provides another method for fastening the first conductive element 10 and the second conductive element 20.

[0260] In some embodiments of this application, the single cell further includes a second insulating sleeve 56, which is sleeved on the through post 25, and the first conductive member 10 and the second conductive member 20 at least partially sandwich the second insulating sleeve 56.

[0261] The second isolation sleeve 56 enhances the airtightness at the electrical conductivity hole 111. Due to the clamping of the first conductive element 10 and the second conductive element 20, the second isolation sleeve 56 can further fill the surface defects of the parts that may compromise airtightness by adapting to the slight deformation of the surfaces of the two elements.

[0262] Please refer to the following: Figure 13 As shown, Figure 13 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, the fastener 60, and the second isolation sleeve 56 provided in another embodiment of this utility model.

[0263] Furthermore, the first conductive element 10 includes a plate 11 and a boss 12. A conductive hole 111 is formed in the plate 11, and the boss 12 protrudes from the inner wall of the conductive hole 111. The boss 12 and the baffle 26 clamp the second isolation sleeve 56.

[0264] The second isolation sleeve 56 is clamped by the second conductive element 20 and the boss 12, which can better position the second isolation element and prevent the second isolation element from being pushed out of the conductive hole 111 during the insertion of the second conductive element 20, thus affecting the assembly effect and sealing ability.

[0265] Furthermore, the height of boss 12 is H2, where 0.5mm < H2 ≤ 5mm.

[0266] The height of the boss 12 affects its load-bearing capacity. If the height of the boss 12 is too small, it may be crushed by the second conductive component 20. If the height of the boss 12 is too large, the space for placing the second insulating component will be too small, affecting the sealing effect. 0.5mm < H2 ≤ 5mm is the choice to minimize the space occupied by the boss 12 while ensuring its strength.

[0267] Optionally, the height of the boss 12 is H2, and the thickness of the first conductive element 10 is L11, where 20% ≤ H2 / L11 ≤ 50%.

[0268] The height of the boss 12 is also affected by the thickness of the first conductive element 10. In actual production, the height of the boss 12 needs to ensure its own strength and also needs to take into account the thickness of the first conductive element 10. 20%≤H2 / L11≤50% can provide as much space as possible for the second insulating element while ensuring the strength of the boss 12 itself.

[0269] Optionally, the height of the boss 12 is H2, the thickness of the first conductive element 10 is L11, the natural length of the second isolation sleeve 56 is L12, and H2+L12>L11.

[0270] The sum of the height of the boss 12 and the natural length of the second isolation sleeve 56 is greater than the thickness of the first conductive element 10. That is, during the process of the second conductive element 20 being inserted into the conductive hole 111 and assembled into place, the second isolation sleeve 56 is squeezed, its length becomes shorter and its thickness increases, resulting in a better sealing effect.

[0271] Please refer to the following: Figure 14 As shown, Figure 14 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, the fastener 60, and the second isolation sleeve 56 provided in another embodiment of this utility model.

[0272] Optionally, the second isolation sleeve 56 includes a ring sleeve portion 561 and a gasket portion 562. The ring sleeve portion 561 is at least partially inserted into the electrical conductivity hole 111, and the gasket portion 562 is at least partially clamped by the retaining edge 26 and the first conductive member 10.

[0273] The gasket portion 562 of the second isolation sleeve 56 is clamped by the second conductive member 20 and the first conductive member 10, which fixes the position of the second isolation sleeve 56 by the edge of the conductive hole 111, preventing the second isolation sleeve 56 from sliding into the conductive hole 111 and causing assembly errors.

[0274] Furthermore, the outer diameter of the gasket portion 562 is D10, and the outer diameter of the flange 26 is D11, with 70% ≤ D11 / D10 ≤ 120%.

[0275] The diameter of the gasket portion 562 should be as close as possible to the outer diameter of the flange 26. Excessive difference in size between the two will result in redundant structures and increase production costs. 70% ≤ D11 / D10 ≤ 120%. Provided the machining accuracy allows, D11 / D10 can be selected as 98%, 100%, or 102%.

[0276] Optionally, the thickness of the gasket portion 562 is L13, where 0.5 ≤ L13 ≤ 1.5 mm.

[0277] The thickness of the gasket portion 562 is an important parameter affecting the insulation and sealing performance of the second separator 56. If the gasket portion 562 is too thin, it cannot seal well and is easily crushed during tightening. If the second separator 56 is too thick, it will occupy extra space and affect the space utilization rate of the individual battery.

[0278] Please refer to the following: Figure 15 and Figure 16 As shown, Figure 15 This is an overall cross-sectional view of a single battery provided in another embodiment of this utility model. Figure 16 yes Figure 15 A magnified view of a portion of region D.

[0279] In some embodiments of this application, the second conductive element 20 passes through the conductive hole 111 and is snapped together with the first conductive element 10.

[0280] The second conductive element 20 and the first conductive element 10 are snapped together, that is, the part of the second conductive element 20 whose outer diameter is larger than the conductive hole 111 is squeezed out from the conductive hole 111 and snapped together with the other end of the conductive hole 111. The assembly process is mature and the production efficiency is high.

[0281] Specifically, the first conductive element 10 includes a first surface and a second surface arranged opposite to each other, and the second conductive element 20 includes a base 28, a connecting rod 27 and a buckle 29 connected in sequence. The connecting rod 27 has a conductive hole 111 passing through it. The base 28 is connected to one end of the connecting rod 27 and abuts against the second surface. The buckle 29 is connected to the end of the connecting rod 27 away from the base 28 and is snapped onto the first surface.

[0282] The buckle 29 is engaged with the first surface to fix the second conductive component 20 to the first surface, and the base 28 abuts against the second surface to prevent the second conductive component 20 from sliding into the conductive hole 111 or squeezing the battery cell assembly 30.

[0283] Furthermore, the outer diameter of the base 28 is D12, where 2mm ≤ D12 ≤ 20mm.

[0284] The diameter of the base 28 determines the pressure-bearing capacity of the second conductive element 20 during the snap-fit ​​process. This is not affected by the conductive hole 111. An excessively large base 28 will undoubtedly occupy extra space. Therefore, 2mm≤D12≤20mm can avoid damage to the base 28 during the snap-fit ​​process while saving space as much as possible. D12 is preferably 4mm, 6mm, or 8mm.

[0285] Optionally, the diameter of the electrical conductivity hole 111 is D1, and the outer diameter of the base 28 is D12, where 130% ≤ D12 / D1 ≤ 200%.

[0286] The selection of the base 28 should also refer to the electrical conductivity hole 111. If the size of the base 28 is too small, there is a risk that the base 28 will be directly inserted into the electrical conductivity hole 111 due to interference fit. If the size of the base 28 is too large, it will result in the occupation of extra space. 130% ≤ D12 / D1 ≤ 200% is the preferred solution. Under the premise that the machining accuracy allows, D12 / D1 is preferably 130%, 132%, or 135%.

[0287] Optionally, the thickness of the base 28 is L14, where 0.2mm≤L14≤2mm.

[0288] The thickness of the base 28 also affects the pressure resistance during the snap-fit ​​process. A base 28 that is too thin is prone to breakage during snap-fit, while a base 28 that is too large will occupy extra space. Therefore, 0.2mm≤L14≤2mm can avoid damage to the base 28 during the snap-fit ​​process while saving space as much as possible. The preferred values ​​for L14 are 0.5mm and 1mm.

[0289] Please refer to the following: Figure 17 As shown, Figure 17 This is a schematic diagram of the cooperation between the first conductive element 10 and the second conductive element 20 provided in another embodiment of this utility model.

[0290] Optionally, the outer diameter of the latch 29 decreases as it moves away from the base 28.

[0291] The outer diameter of the snap 29 decreases as it moves away from the base 28, meaning that the second conductive element 20 has a guiding slope at the insertion front end, which is beneficial for the alignment of the snap.

[0292] Furthermore, the diameter of the electrical conductivity hole 111 is D1, the maximum outer diameter of the buckle 29 is D13, and 102% ≤ D13 / D1 ≤ 150%.

[0293] To ensure proper contact between the latch 29 and the first surface, the maximum outer diameter of the latch 29, i.e., the outer edge of its contact area with the first surface, should be sufficiently large. However, since the latch 29 passes through the electrical conductivity hole 111 with an interference fit, an excessively large outer diameter of the latch 29 may cause the electrical conductivity hole 111 to crack. A ratio of 102% ≤ D13 / D1 ≤ 150% can reduce the risk of cracking the electrical conductivity hole 111 while ensuring stable contact between the latch 29 and the first surface. Preferably, D13 / D1 is 105%, 108%, or 110%.

[0294] Optionally, the diameter of the electrical conductivity hole 111 is D1, and the minimum outer diameter of the buckle 29 is D14, with 60% ≤ D14 / D1 ≤ 97%.

[0295] The minimum outer diameter of the latch 29, that is, the portion of the latch 29 that first inserts into the conductive hole 111, serves to guide the insertion of the second conductive element 20. A sufficiently small D14 is beneficial for guiding the insertion of the second conductive element 20, while an excessively small D14 will not enhance the guiding effect and may instead cause the second conductive element 20 to collide with the edge of the conductive hole 111 during insertion. 60% ≤ D14 / D1 ≤ 97% is a range of values ​​with good guiding effect, and D14 / D1 is preferably 85%, 90%, or 92%.

[0296] Optionally, on any cross section passing through the axis of the buckle 29, the angle between the tangent of the outer contour of the buckle 29 and the first surface is A3, where 60% ≤ A3 ≤ 85%.

[0297] The angle between the tangent of the outer contour of the snap fastener 29 and the first surface determines the difficulty of inserting the snap fastener 29 into the electrical conductivity hole 111. A larger A3 makes it easier to guide alignment after the sidewall of the snap fastener 29 contacts the edge of the electrical conductivity hole 111, but also requires higher precision from the snap fastener insertion machine. A smaller A3, while reducing the alignment guiding force after the sidewall of the snap fastener 29 contacts the edge of the electrical conductivity hole 111, provides a larger eccentricity error range for the snap fastener 29 insertion. With the same maximum outer diameter, a snap fastener 29 with a smaller A3 can be guided to alignment with a larger eccentricity. A value of 60% ≤ A3 ≤ 85% maximizes the eccentricity error range while ensuring sufficient contact force at the edge of the electrical conductivity hole 111 for guidance. A3 is preferably 70% or 75%.

[0298] In some embodiments of this application, the single cell further includes a second insulating sleeve 56, which is sleeved on the through post 25, and the first conductive member 10 and the second conductive member 20 at least partially sandwich the second insulating sleeve 56.

[0299] The second isolation sleeve 56 enhances the airtightness at the electrical conductivity hole 111. Due to the clamping of the first conductive element 10 and the second conductive element 20, the second isolation sleeve 56 can further fill the surface defects of the parts that may compromise airtightness by adapting to the slight deformation of the surfaces of the two elements.

[0300] Please refer to the following: Figure 18 As shown, Figure 18 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, and the second isolation sleeve 56 provided in another embodiment of this utility model.

[0301] Furthermore, the first conductive element 10 includes a plate 11 and a boss 12. A conductive hole 111 is formed in the plate 11, and the boss 12 protrudes from the inner wall of the conductive hole 111. The boss 12 and the base 28 clamp a second isolation sleeve 56.

[0302] The second isolation sleeve 56 is clamped by the second conductive element 20 and the boss 12, which can better position the second isolation element and prevent the second isolation element from being pushed out of the conductive hole 111 during the insertion of the second conductive element 20, thus affecting the assembly effect and sealing ability.

[0303] Specifically, the height of boss 12 is H2, where 1mm ≤ H2 ≤ 5mm.

[0304] The height of the boss 12 affects its load-bearing capacity. If the height of the boss 12 is too small, it may be crushed by the second conductive component 20. If the height of the boss 12 is too large, the space for placing the second insulating component will be too small, affecting the sealing effect. 0.5mm < H2 ≤ 5mm is the choice to minimize the space occupied by the boss 12 while ensuring its strength.

[0305] Specifically, the height of the boss 12 is H2, and the thickness of the first conductive element 10 is L11, with 40% ≤ H2 / L11 ≤ 60%.

[0306] The height of the boss 12 is also affected by the thickness of the first conductive element 10. In actual production, the height of the boss 12 needs to ensure its own strength and also needs to take into account the thickness of the first conductive element 10. 20%≤H2 / L11≤60% can provide as much space as possible for the second insulating element while ensuring the strength of the boss 12 itself.

[0307] Specifically, the height of the boss 12 is H2, the thickness of the first conductive element 10 is L11, the natural length of the second isolation sleeve 56 is L12, and H2+L12≥L11.

[0308] The sum of the height of the boss 12 and the natural length of the second isolation sleeve 56 is greater than the thickness of the first conductive element 10. That is, during the process of the second conductive element 20 being inserted into the conductive hole 111 and assembled into place, the second isolation sleeve 56 is squeezed, its length becomes shorter and its thickness increases, resulting in a better sealing effect.

[0309] Please refer to the following: Figure 19 As shown, Figure 19This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, and the second isolation sleeve 52 provided in another embodiment of this utility model.

[0310] Optionally, the second isolation sleeve 56 includes a ring sleeve portion 561 and a gasket portion 562. The ring sleeve portion 561 is at least partially inserted into the electrical conductivity hole 111, and the gasket portion 562 is at least partially clamped by the base 28 and the first conductive member 10.

[0311] The gasket portion 562 of the second isolation sleeve 56 is clamped by the second conductive member 20 and the first conductive member 10, which fixes the position of the second isolation sleeve 56 by the edge of the conductive hole 111, preventing the second isolation sleeve 56 from sliding into the conductive hole 111 and causing assembly errors.

[0312] Specifically, the outer diameter of the gasket part 562 is D10, and the outer diameter of the base 28 is D12, with 70% ≤ D12 / D10 ≤ 120%.

[0313] The diameter of the gasket 562 should be as close as possible to the outer diameter of the base 28. A large difference in size will result in redundant structure and increase production costs. 70% ≤ D12 / D10 ≤ 120%. Provided the machining accuracy allows, D12 / D10 can be selected as 98%, 100%, or 102%.

[0314] Specifically, the thickness of the gasket portion 562 is L13, 0.5≤L13≤1.5mm.

[0315] The thickness of the gasket portion 562 is an important parameter affecting the insulation and sealing performance of the second separator 56. If the gasket portion 562 is too thin, it cannot seal well and is easily squeezed and damaged during snap-fitting. If the second separator 56 is too thick, it will occupy extra space and affect the space utilization rate of the individual battery.

[0316] Please refer to the following: Figure 20 As shown, Figure 20 yes Figure 2 A magnified view of a portion of region E in the middle.

[0317] In some embodiments of this application, the first conductive element 10 is further formed with a pressure relief groove 114, which is recessed on the surface of the first conductive element 10 to avoid the conductive hole 111.

[0318] The setting of the pressure relief groove 114 reduces the structural strength of the first conductive element 10 in the corresponding area, making it a structural weakness of the single cell casing. When an accident occurs inside the single cell, such as thermal runaway, causing the internal pressure to rise, the first conductive element 10 in the pressure relief groove 114 area is destroyed, the internal pressure of the single cell is released, and the excessive internal pressure accumulation prevents an explosion.

[0319] Furthermore, the distance between the edge of the pressure relief groove 114 and the edge of the electrical conductivity hole 111 is L15, where 2mm < L15 < 35mm.

[0320] The pressure relief groove 114 is designed to avoid the conductive hole 111. The distance between the edge of the pressure relief groove 114 and the edge of the conductive hole 111 will have an additional impact on the structural strength of the first conductive component 10. When the pressure relief groove 114 and the conductive hole 111 are too close, there is a risk that the pressure relief groove 114 will crack during the assembly of the second conductive component 20. 2mm < L15 < 35mm can ensure the stability of the assembly of the second conductive component 20 while keeping the structure as compact as possible. L15 is preferably 2mm, 3mm, or 5mm.

[0321] Optionally, the maximum width of the pressure relief groove 114 is L16, where 0.05mm≤L16≤5mm.

[0322] The width of the pressure relief groove 114 affects the distribution of weak surfaces in the structure it forms. If the pressure relief groove 114 is too narrow, the pressure relief effect will be weak; if the pressure relief groove 114 is too wide, it will have a significant impact on the structural strength of the first conductive element 10, posing a risk of breakage even under normal operating conditions. A width of 0.05mm ≤ L16 ≤ 5mm can satisfy the pressure relief function of the pressure relief groove 114 while ensuring the structural strength of the first conductive element 10. Preferably, L16 is 0.1mm or 0.2mm.

[0323] Optionally, the first conductive element 10 includes a first surface and a second surface disposed opposite to each other, the first surface being oriented toward the cell assembly 30, and the pressure relief groove 114 being formed on the second surface.

[0324] The pressure relief groove 114 is located on the second side. When the internal pressure of a single cell rises, the first side of the first conductive element 10 is pressed, and the first conductive element 10 bulges outward. The pressure relief groove 114 tends to open, and there is also stress concentration at the bottom of the pressure relief groove 114, which is conducive to the destruction of the first conductive element 10 when the internal pressure of the single cell rises.

[0325] Specifically, the distance between the bottom of the pressure relief groove 114 and the first surface is L17, where 0.02mm≤L17≤1.5mm.

[0326] If the distance between the bottom of the pressure relief groove 114 and the first surface is too large, the pressure relief effect will be weak. If the distance between the bottom of the pressure relief groove 114 and the first surface is too small, it will have a significant impact on the structural strength of the first conductive element 10, making it susceptible to breakage even under normal use conditions. A distance of 0.02mm ≤ L17 ≤ 1.5mm can satisfy the pressure relief function of the pressure relief groove 114 while ensuring the structural strength of the first conductive element 10. Preferably, L17 is 0.1mm or 0.15mm.

[0327] It should be noted that the bottom here does not refer to a specific plane, but should be understood as the position within the pressure relief groove 114 closest to the first surface, and should not be used to limit the shape of this embodiment.

[0328] Optionally, the included angle between the pressure relief groove 114 and the two groove walls is A4, where 20°≤A4≤90°.

[0329] The included angle A4 is related to the stress concentration at the bottom of the pressure relief groove 114. When the included angle A4 is too small, the stress concentration at the bottom of the pressure relief groove 114 will be more obvious, which will also cause the first conductive element 10 to crack when the single cell is working normally and generating heat. When the included angle A4 is too large, the width of the widest part of the pressure relief groove 114 will be too large, which will also affect the strength of the first conductive element 10. Through experiments, it can be found that 20°≤A4≤90° is a better included angle range, and A4 is further preferred to be 50° or 60°.

[0330] Please refer to the following: Figure 21 As shown, Figure 21 This is a schematic diagram of the cooperation between the pressure relief groove 114 and the second conductive element 20 provided in another embodiment of this utility model.

[0331] Optionally, the pressure relief groove 114 has a trapezoidal cross-section perpendicular to its extension direction, with the lower base of the trapezoid located on the surface of the first conductive element 10.

[0332] The pressure relief groove 114 has a flat bottom, which can alleviate stress concentration to a certain extent. Under the premise that the depth of the pressure relief groove 114 and the thickness of the first conductive element 10 remain unchanged, the structural strength of the first conductive element 10 is enhanced, and accidental damage to the first conductive element 10 during normal use is avoided.

[0333] Specifically, the length of the upper base of the trapezoid is L18, and 0.02mm≤L18≤3mm.

[0334] If the length of the upper bottom is too small, its effect of relieving stress concentration will not be obvious enough. If the length of the upper bottom is too large, the pressure relief groove 114 will be too wide, which will also affect the structural strength of the first conductive component 10. 0.02mm≤L18≤3mm is the range of values ​​that are not easy to generate stress concentration under the premise of keeping the pressure relief groove 114 relatively narrow. L18 is preferably 1mm.

[0335] Please refer to the following: Figure 22 As shown, Figure 22 This is a schematic diagram of the cooperation between the pressure relief groove 114 and the second conductive element 20 provided in another embodiment of this utility model.

[0336] Optionally, the bottom of the pressure relief groove 114 has rounded corners.

[0337] The bottom of the pressure relief groove 114 has rounded corners, which can alleviate stress concentration to a certain extent. Under the premise that the depth of the pressure relief groove 114 and the thickness of the first conductive element 10 remain unchanged, the structural strength of the first conductive element 10 is enhanced, and accidental damage to the first conductive element 10 during normal use is avoided.

[0338] Specifically, the radius of the rounded corner is R1, the maximum width of the pressure relief groove 114 is L16, and 20% ≤ R1 / L16 ≤ 100%.

[0339] If the radius of the fillet is too small, its effect of relieving stress concentration will not be obvious enough. If the radius of the fillet is too large, the pressure relief groove 114 will be too wide, which will also affect the structural strength of the first conductive component 10. 20%≤R1 / L16≤100% is the range of values ​​that are not easy to generate stress concentration under the premise of keeping the pressure relief groove 114 relatively narrow. R1 / L16 is preferably 50%.

[0340] Please refer to the following: Figure 23 As shown, Figure 23 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, and the fourth insulating layer 54 provided in this embodiment of the utility model.

[0341] In some embodiments of this application, the single cell also includes a fourth insulating layer 54, which covers the surface of the first conductive element 10 facing the cell assembly 30.

[0342] The fourth isolation layer 54 covers the surface of the first conductive element 10 facing the cell assembly 30, at least partially isolating the first conductive element 10 from the electrolyte, thereby slowing down the corrosion rate of the first conductive element 10 and extending the service life of the single cell.

[0343] For example, the fourth isolation layer 54 is either a nickel plating or an iron alloy plating.

[0344] The nickel or iron alloy plating has electrical conductivity. When the fourth isolation layer 54 is sandwiched between the first conductive element 10 and the second conductive element 20, the fourth isolation layer 54 can share part of the current. While isolating the first conductive element 10 and the second conductive element 20 from the area immersed in the electrolyte, it will not significantly affect the current carrying capacity of the single cell.

[0345] For example, the fourth isolation layer 54 is either a PP film or PPS.

[0346] PP film and PPS film are relatively mature protective materials in the field of lithium batteries, with low cost and high processing efficiency.

[0347] Specifically, the area of ​​the first conductive element 10 near the cell assembly 30 is S1, and the projected area of ​​the fourth insulating layer 54 on the surface of the first conductive element 10 is S8, where 5% ≤ S8 / S1 ≤ 97%.

[0348] The area ratio of the fourth isolation layer 54 is related to its isolation capacity, and 5% ≤ S8 / S1 ≤ 97% is the optimal range for the experiment.

[0349] Specifically, the thickness of the fourth isolation layer 54 is L19, 0.05mm≤L19≤2mm.

[0350] The isolation effect of the fourth isolation layer 54 is positively correlated with its thickness. If the fourth isolation layer 54 is too thin, there is a risk of it being penetrated. If the fourth isolation layer 54 is too thick, it will cause additional space occupation and increase production costs. 0.05mm≤L19≤2mm is the range of values ​​that minimizes space occupation while ensuring the isolation effect.

[0351] Specifically, the thickness of the fourth insulating layer 54 is uniformly distributed across the entire surface of the first conductive element 10.

[0352] The uniformly distributed fourth isolation layer 54 provides uniform isolation effect, has a simple processing technology, and high production efficiency.

[0353] Please refer to the following: Figure 24 As shown, Figure 24 This is a schematic diagram showing the cooperation of the first conductive element 10, the second conductive element 20, and the fourth insulating layer 54 provided in another embodiment of this utility model.

[0354] Optionally, the thickness of the fourth insulating layer 54 increases as it approaches the conductive hole 111.

[0355] There are multiple component contact surfaces near the electrical conductivity hole 111. Applying a thicker layer of the fourth isolation layer 54 to the electrical conductivity hole 111 can effectively enhance the isolation effect in the corresponding area.

[0356] In some embodiments of this application, the thickness of the first conductive element 10 is L11, where 0.5mm≤L11≤2mm.

[0357] The first conductive element 10 carries the functions of conductivity and physical protection. If the first conductive element 10 is too thin, its current carrying capacity and structural strength will be poor. If it is too thick, it will increase the production cost and add weight and volume. 0.5mm≤L11≤2mm is a range of values ​​that can maintain good structural strength and current carrying capacity while minimizing space occupation. L11 is preferably 1mm.

[0358] It should be noted that the first conductive element 10 may be composed of multiple plates 11 spliced ​​together, with each plate 11 located on a different plane. In this case, L11 should be defined as the thickness of the plate 11 rather than the distance between the surfaces of the two farthest plates 11.

[0359] Please refer to the following: Figure 25 As shown, Figure 25 This is a schematic diagram showing the connection relationship between the first conductive element 10 and the housing 70 provided in this embodiment of the utility model.

[0360] In some embodiments of this application, the single battery cell also includes a housing 70, with an opening on one side of the housing 70. A first conductive element 10 blocks the opening of the housing 70 and together with the housing 70 forms an accommodating space, and the cell assembly 30 is disposed within the accommodating space.

[0361] The first conductive element 10 seals the opening and forms an accommodating space with the housing 70. The battery cell assembly 30 is disposed in the accommodating space. This allows the connection of the first conductive element 10 and the second conductive element 20 to be completed first. When the first conductive element 10 is fastened to the housing 70, the second conductive element 20 abuts against the battery cell assembly 30. Alternatively, the assembly of the first conductive element 10, the housing 70 and the battery cell assembly 30 can be completed first, and then the second conductive element 20 can be inserted through the conductive hole 111 and abut against the battery cell assembly 30. The assembly process is more flexible.

[0362] Furthermore, the single cell also includes a second weld 42, through which the first conductive element 10 and the casing 70 are connected.

[0363] The first conductive element 10 and the casing 70 are connected by the second weld 42, which ensures the connection strength and airtightness of the single battery casing. Moreover, since the second weld 42 undertakes a large part of the connection function, it also indirectly reduces the welding strength requirements between the second conductive element 20 and the cell assembly 30, making it less likely for the second conductive element 20 and the cell assembly 30 to break the circuit.

[0364] Specifically, the height of the second weld 42 protruding from the surface of the shell 70 is H3, where 0mm≤H3≤3mm.

[0365] The portion of the second weld 42 that protrudes from the surface of the casing 70 increases the probability of scratching adjacent individual cells within the battery pack. Therefore, a configuration of 0mm≤H3≤3mm is used to protect the individual cells and extend their lifespan. Where conditions permit, a mill or similar device can be used to make H3 as close to 0mm as possible.

[0366] Specifically, the width of the second weld 42 is L20, where 2mm ≤ L20 ≤ 6mm.

[0367] Because the mechanical properties of the weld are usually greater than those of the base material, a sufficiently large second weld 42 width can ensure the connection strength between the casing 70 and the first conductive element 10. However, due to the limitations of the strength of the casing 70 and the first conductive element 10 themselves, an excessively large second weld 42 cannot improve the overall strength of the single-cell battery casing. 2mm≤L20≤6mm can minimize energy waste while ensuring the connection strength between the first conductive element 10 and the casing 70.

[0368] Optionally, the first conductive element 10 includes a first plate 13, a second plate 14 and a third plate 15. A conductive hole 111 is formed in the first plate 13. The third plate 15 is wrapped around the first plate 13. The housing 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. The first plate 13 and the second plate 14 are embedded in the opening of the housing 70.

[0369] The first plate 13 and the second plate 14 are embedded in the opening of the housing 70. They can be used to position the first conductive component 10 and the housing 70 without molds before the third plate 15 and the housing 70 are welded. This serves as a foolproof structure and avoids the risk of assembly workers installing the first conductive component 10 backwards.

[0370] Furthermore, the first plate 13 and the second plate 14 are connected by an arc.

[0371] When the inner edge of the opening of the housing 70 abuts the arc, there is a spontaneous tendency to guide the first plate 13 and the second plate 14 into the opening. In addition to positioning, it can also guide the assembly and reduce the requirements for alignment accuracy in the assembly process.

[0372] Specifically, the radius of the arc is R2, where 0.1mm ≤ R2 ≤ 2mm.

[0373] A radius that is too small results in a small alignment and guidance area, leading to a weaker guiding effect. Conversely, a radius that is too large will reduce the connection strength between the first plate 13 and the second plate 14. A radius of 0.1mm ≤ R2 ≤ 2mm can achieve the most significant guiding effect while ensuring the structural strength of the first conductive element 10. R2 is preferably 0.5mm or 1mm.

[0374] Specifically, the radius of the arc is R2, the thickness of the first plate 13 is L21, and 20% ≤ R2 / L21 ≤ 100%.

[0375] The radius of the arc is also affected by the thickness of the first plate 13. A radius that is too small results in a smaller alignment and guidance area and a weaker guidance effect, while a radius that is too large will reduce the connection strength between the first plate 13 and the second plate 14. A radius of 20% ≤ R2 / L21 ≤ 100% can achieve the most significant guidance effect while ensuring the structural strength of the first conductive element 10. R2 / L21 is preferably 50%.

[0376] Optionally, there is an assembly gap 80 between the second plate 14 and the housing 70.

[0377] The presence of the assembly gap 80 facilitates the insertion of the first plate 13 and the second plate 14, reducing the alignment accuracy requirements during the assembly process.

[0378] Specifically, the width of the assembly gap 80 is L22, 0.1mm≤L22≤0.5mm.

[0379] An excessively small assembly gap 80 makes it difficult to significantly optimize the assembly process, while an excessively large assembly gap 80 will affect the airtightness between the first conductive component 10 and the housing 70. Therefore, configuring a gap of 0.1mm ≤ L22 ≤ 0.5mm can minimize the alignment accuracy requirement while ensuring airtightness. L22 is preferably 0.4mm or 0.5mm. It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this embodiment of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0380] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0381] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0382] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the design concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A single-cell battery, characterized in that, include: A first conductive element has a conductive hole that penetrates the first conductive element in the thickness direction. A second conductive element is provided through the conductive hole, and the second conductive element is fixed and electrically connected to the first conductive element; The battery cell assembly is welded to the second conductive component.

2. The single-cell battery according to claim 1, characterized in that, The second conductive element also has a welding hole formed thereon, and the opening direction of the welding hole is towards the side of the second conductive element away from the cell assembly.

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

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

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

6. The single-cell battery according to claim 2, characterized in that, The distance between the bottom of the welding hole and the surface of the second conductive element near the cell assembly is L4, where 0.05mm≤L4≤2mm.

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

8. The single-cell battery according to claim 7, characterized in that, The area of ​​the first conductive element near the battery cell assembly is S1, and the projected area of ​​the contact surface between the second conductive element and the busbar on the first conductive element is S2, where 20%≤S2 / S1≤90%.

9. The single-cell battery according to claim 7, characterized in that, The second conductive element is connected to the busbar by a first weld. The projected area of ​​the first weld on the surface of the busbar is S3, and the surface area of ​​the busbar on the side closest to the structure of the first conductive element is S4. S3 / S4≥10%.

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

11. The single-cell battery according to claim 7, characterized in that, The second conductive element is made of the same material as the busbar.

12. The single-cell battery according to claim 1, characterized in that, The battery cell assembly includes an electrically connected core and a tab, wherein the tab and the second conductive element are welded together.

13. The single-cell battery according to claim 12, characterized in that, The second conductive element and the electrode tab are made of the same material.

14. The single-cell battery according to claim 1, characterized in that, There are multiple conductive holes, and the second conductive element is provided in a corresponding manner to each conductive hole.

15. The single-cell battery according to claim 14, characterized in that, A plurality of the aforementioned conductive holes are arranged in a circumferential array on the first conductive element.

16. The single-cell battery according to claim 1, characterized in that, The material of the second conductive element is copper.

17. The single-cell battery according to claim 16, characterized in that, The single cell also includes a first insulating layer that encloses the second conductive element, with at least a partial exposure of the side of the second conductive element closest to the cell assembly.

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

19. The single-cell battery according to claim 17, characterized in that, The area of ​​the exposed portion of the second conductive element on the side near the cell assembly is S5, and the area of ​​the first conductive element on the side near the cell assembly is S1, where 40%≤S5 / S1≤100%.

20. The single-cell battery according to claim 1, characterized in that, The second conductive element and the first conductive element are riveted together.

21. The single-cell battery according to claim 20, characterized in that, The first conductive element includes a first surface and a second surface opposite to each other, and the second conductive element includes: The rivet is inserted through the electrical conductivity hole; A rivet base is connected to one end of the rivet post, and the rivet base abuts against the first surface; A rivet is connected to the end of the rivet post away from the rivet seat, and the rivet is riveted to the second surface.

22. The single-cell battery according to claim 21, characterized in that, The outer edge of the end of the rivet away from the rivet seat is provided with an outer chamfer. On any cross section passing through the axis of the rivet, the angle between the outer chamfer and the second surface is A1, where 10°≤A1≤85°.

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

24. The single-cell battery according to claim 21, characterized in that, The thickness of the rivet is L6, and the projection length of the second conductive element in the thickness direction of the rivet is L7, where 10%≤L6 / L7≤40%.

25. The single-cell battery according to claim 21, characterized in that, The diameter of the conductive hole is D1, and the outer diameter of the rivet is D3, where 120% ≤ D3 / D1 ≤ 200%.

26. The single-cell battery according to claim 21, characterized in that, The diameter of the rivet base is D4, where 2mm ≤ D4 ≤ 20mm.

27. The single-cell battery according to claim 21, characterized in that, The diameter of the conductive hole is D1, and the diameter of the rivet base is D4, where 130% ≤ D4 / D1 ≤ 200%.

28. The single-cell battery according to claim 21, characterized in that, The thickness of the rivet base is L8, where 0.05mm ≤ L8 ≤ 2mm.

29. The single-cell battery according to claim 21, characterized in that, The single battery cell also includes a first insulating sleeve, the rivet post passes through the first insulating sleeve, and the rivet base and the first surface are sandwiched between the first insulating sleeve.

30. The single-cell battery according to claim 29, characterized in that, The diameter of the rivet base is D4, and the outer diameter of the first isolation sleeve is D5, with 70% ≤ D4 / D5 ≤ 120%.

31. The single-cell battery according to claim 29, characterized in that, The thickness of the first isolation sleeve is L9, 0.5≤L9≤1.5mm.

32. The single-cell battery according to claim 21, characterized in that, The second conductive element also has a riveting hole, the opening of which faces the side of the second conductive element away from the battery cell assembly.

33. The single-cell battery according to claim 32, characterized in that, The edge of the rivet hole is provided with an inner chamfer. On any cross section passing through the axis of the rivet hole, the angle between the inner chamfer plane and the second surface is A2, where 30°≤A2≤85°.

34. The single-cell battery according to claim 32, characterized in that, The diameter of the rivet hole is D6, the minimum outer diameter of the second conductive component is D7, and 30%≤D6 / D7≤80%.

35. The single-cell battery according to claim 1, characterized in that, The single cell also includes a fastener, the second conductive element includes a through post and a stop, the through post passes through the conductive hole, the stop abuts against the first conductive element, and the fastener passes through at least one of the first conductive element and the second conductive element to achieve the connection between the first conductive element and the second conductive element.

36. The single-cell battery according to claim 35, characterized in that, The retaining edge has a first hole, and the fastener passes through the first hole and connects to the first conductive element.

37. The single-cell battery according to claim 36, characterized in that, A second insulating layer is provided between the first conductive element and the second conductive element.

38. The single-cell battery according to claim 37, characterized in that, The second isolation layer is at least one of PP film or PPS film.

39. The single-cell battery according to claim 36, characterized in that, The fastener has a third insulating layer on the surface that contacts the first conductive element and the second conductive element.

40. The single-cell battery according to claim 39, characterized in that, The third isolation layer is a nickel plating layer.

41. The single-cell battery according to claim 36, characterized in that, The distance between the surface of the through-post near the cell assembly and the surface of the first conductive element near the cell assembly is H1, where 0.8 ≤ H1 ≤ 2 mm.

42. The single-cell battery according to claim 36, characterized in that, The projected area of ​​the outer edge of the stop on the first conductive element is S6, and the contact area between the stop and the first conductive element is S7, where 5% ≤ S7 / S6 ≤ 35%.

43. The single-cell battery according to claim 36, characterized in that, There are multiple first holes on each of the said flanges.

44. The single-cell battery according to claim 43, characterized in that, Multiple first holes are distributed in a circumferential array on the flange.

45. The single-cell battery according to claim 36, characterized in that, The retaining edge abuts against the side of the first conductive element away from the cell assembly.

46. ​​The single-cell battery according to claim 36, characterized in that, The diameter of the first hole is D8, and 2.5mm≤D8≤16mm.

47. The single-cell battery according to claim 36, characterized in that, The first conductive element has a second hole, and the fastener passes through the first hole and is inserted into the second hole.

48. The single-cell battery according to claim 47, characterized in that, The fastener is a screw, and the fastener is threaded into the second hole.

49. The single-cell battery according to claim 36, characterized in that, The fastener includes a first part and a second part that are connected to each other. The first part passes through the first hole, and the second part abuts against the side of the second conductive member away from the first conductive member.

50. The single-cell battery according to claim 49, characterized in that, The diameter of the first part is D9, and 2.5mm≤D9≤16mm.

51. The single-cell battery according to claim 49, characterized in that, The thickness of the second part is L10, where 0.5mm ≤ L10 ≤ 2mm.

52. The single-cell battery according to claim 35, characterized in that, The first conductive element has a third hole, and the fastener passes through the third hole and is connected to the second conductive element.

53. The single-cell battery according to claim 35, characterized in that, The single cell also includes a second insulating sleeve, which is sleeved on the through post, and the first conductive element and the second conductive element at least partially sandwich the second insulating sleeve.

54. The single-cell battery according to claim 53, characterized in that, The first conductive element includes a plate and a boss. The conductive hole is formed in the plate, and the boss protrudes from the inner wall of the conductive hole. The boss and the retaining edge sandwich the second isolation sleeve.

55. The single-cell battery according to claim 54, characterized in that, The height of the boss is H2, where 0.5mm < H2 ≤ 5mm.

56. The single-cell battery according to claim 54, characterized in that, The height of the boss is H2, and the thickness of the first conductive element is L11, where 20% ≤ H2 / L11 ≤ 50%.

57. The single-cell battery according to claim 54, characterized in that, The height of the boss is H2, the thickness of the first conductive element is L11, and the natural length of the second isolation sleeve is L12, where H2 + L12 > L11.

58. The single-cell battery according to claim 53, characterized in that, The second isolation sleeve includes a ring sleeve portion and a gasket portion. The ring sleeve portion is at least partially inserted into the conductive hole, and the gasket portion is at least partially clamped by the retaining edge and the first conductive element.

59. The single-cell battery according to claim 58, characterized in that, The outer diameter of the gasket portion is D10, and the outer diameter of the retaining edge is D11, with 70% ≤ D11 / D10 ≤ 120%.

60. The single-cell battery according to claim 58, characterized in that, The thickness of the gasket portion is L13, where 0.5 ≤ L13 ≤ 1.5 mm.

61. The single-cell battery according to claim 1, characterized in that, The second conductive element passes through the conductive hole and is snapped together with the first conductive element.

62. The single-cell battery according to claim 61, characterized in that, The first conductive element includes a first surface and a second surface disposed opposite to each other, and the second conductive element includes: The connecting rod passes through the electrical conductivity hole; A base is connected to one end of the connecting rod, and the base abuts against the second surface; A buckle is connected to the end of the connecting rod away from the base, and the buckle is engaged with the first surface.

63. The single-cell battery according to claim 62, characterized in that, The outer diameter of the base is D12, where 2mm ≤ D12 ≤ 20mm.

64. The single-cell battery according to claim 62, characterized in that, The diameter of the conductive hole is D1, and the outer diameter of the base is D12, where 130% ≤ D12 / D1 ≤ 200%.

65. The single-cell battery according to claim 62, characterized in that, The thickness of the base is L14, where 0.2mm≤L14≤2mm.

66. The single-cell battery according to claim 62, characterized in that, The outer diameter of the buckle decreases as it moves away from the base.

67. The single-cell battery according to claim 66, characterized in that, The diameter of the conductive hole is D1, and the maximum outer diameter of the buckle is D13, where 102%≤D13 / D1≤150%.

68. The single-cell battery according to claim 66, characterized in that, The diameter of the conductive hole is D1, and the minimum outer diameter of the buckle is D14, with 60%≤D14 / D1≤97%.

69. The single-cell battery according to claim 66, characterized in that, On any cross section passing through the axis of the buckle, the angle between the tangent of the outer contour of the buckle and the first surface is A3, where 60%≤A3≤85%.

70. The single-cell battery according to claim 62, characterized in that, The single cell also includes a second insulating sleeve, which is sleeved on the second conductive element, and the first conductive element and the second conductive element at least partially sandwich the second insulating sleeve.

71. The single-cell battery according to claim 70, characterized in that, The first conductive element includes a plate and a boss. The conductive hole is formed in the plate, and the boss protrudes from the inner wall of the conductive hole. The boss and the base sandwich the second isolation sleeve.

72. The single-cell battery according to claim 71, characterized in that, The height of the boss is H2, where 1mm ≤ H2 ≤ 5mm.

73. The single-cell battery according to claim 71, characterized in that, The height of the boss is H2, and the thickness of the first conductive element is L11, where 40% ≤ H2 / L11 ≤ 60%.

74. The single-cell battery according to claim 71, characterized in that, The height of the boss is H2, the thickness of the first conductive element is L11, the natural length of the second isolation sleeve is L12, and H2+L12≥L11.

75. The single-cell battery according to claim 70, characterized in that, The second isolation sleeve includes a ring portion and a gasket portion. The ring portion is at least partially inserted into the conductive hole, and the gasket portion is at least partially clamped by the base and the first conductive element.

76. The single-cell battery according to claim 75, characterized in that, The outer diameter of the gasket is D10, and the outer diameter of the base is D12, where 70% ≤ D12 / D10 ≤ 120%.

77. The single-cell battery according to claim 75, characterized in that, The thickness of the gasket portion is L13, where 0.5 ≤ L13 ≤ 1.5 mm.

78. The single-cell battery according to any one of claims 1 to 77, characterized in that, The first conductive element also has a pressure relief groove, which is recessed on the surface of the first conductive element to avoid the conductive hole.

79. The single-cell battery according to claim 78, characterized in that, The distance between the edge of the pressure relief groove and the edge of the electrical conductivity hole is L15, where 2mm < L15 < 35mm.

80. The single-cell battery according to claim 78, characterized in that, The maximum width of the pressure relief groove is L16, where 0.05mm ≤ L16 ≤ 5mm.

81. The single-cell battery according to claim 78, characterized in that, The first conductive element includes a first surface and a second surface disposed opposite to each other, the first surface being oriented toward the battery cell assembly, and the pressure relief groove being formed on the second surface.

82. The single-cell battery according to claim 81, characterized in that, The distance between the bottom of the pressure relief groove and the first surface is L17, where 0.02mm≤L17≤1.5mm.

83. The single-cell battery according to claim 78, characterized in that, The included angle between the pressure relief groove and the two groove walls is A4, where 20°≤A4≤90°.

84. The single-cell battery according to claim 78, characterized in that, The pressure relief groove has a trapezoidal cross-section perpendicular to its extension direction, and the lower base of the trapezoid is located on the surface of the first conductive element.

85. The single-cell battery according to claim 84, characterized in that, The length of the upper base of the trapezoid is L18, where 0.02mm ≤ L18 ≤ 3mm.

86. The single-cell battery according to claim 78, characterized in that, The bottom of the pressure relief groove has rounded corners.

87. The single-cell battery according to claim 86, characterized in that, The radius of the fillet is R1, and the maximum width of the pressure relief groove is L16, where 20% ≤ R1 / L16 ≤ 100%.

88. The single-cell battery according to any one of claims 1 to 77, characterized in that, The single cell also includes a fourth insulating layer, which covers the surface of the first conductive element facing the cell assembly.

89. The single-cell battery according to claim 88, characterized in that, The fourth isolation layer is either a nickel plating layer or an iron alloy plating layer.

90. The single-cell battery according to claim 88, characterized in that, The fourth isolation layer is either PP film or PPS.

91. The single-cell battery according to claim 88, characterized in that, The area of ​​the first conductive element near the cell assembly is S1, and the projected area of ​​the fourth insulating layer on the surface of the first conductive element is S8, where 5%≤S8 / S1≤97%.

92. The single-cell battery according to claim 88, characterized in that, The thickness of the fourth isolation layer is L19, where 0.05mm ≤ L19 ≤ 2mm.

93. The single-cell battery according to claim 88, characterized in that, The thickness of the fourth insulating layer is uniformly distributed across the entire surface of the first conductive element.

94. The single-cell battery according to claim 88, characterized in that, The thickness of the fourth isolation layer increases as it approaches the conductive hole.

95. The single-cell battery according to any one of claims 1 to 77, characterized in that, The thickness of the first conductive element is L11, where 0.5mm ≤ L11 ≤ 2mm.

96. The single-cell battery according to any one of claims 1 to 77, characterized in that, The single battery also includes a housing with an opening on one side. The first conductive element blocks the opening of the housing and together with the housing, they form an accommodating space. The battery cell assembly is disposed within the accommodating space.

97. The single-cell battery according to claim 96, characterized in that, The single cell also includes a second weld, through which the first conductive element and the casing are connected.

98. The single-cell battery according to claim 97, characterized in that, The height of the second weld protruding from the surface of the shell is H3, where 0mm ≤ H3 ≤ 3mm.

99. The single-cell battery according to claim 97, characterized in that, The width of the second weld is L20, where 2mm ≤ L20 ≤ 6mm.

100. The single-cell battery according to claim 96, characterized in that, The first conductive element includes a first plate, a second plate, and a third plate. The conductive hole is formed in the first plate. The third plate is wrapped around the first plate. The housing is connected to the third plate. The opposite ends of the second plate are respectively connected to the first plate and the third plate. The first plate and the second plate are embedded in the opening of the housing.

101. The single-cell battery according to claim 100, characterized in that, The first plate and the second plate are connected by an arc.

102. The single-cell battery according to claim 101, characterized in that, The radius of the arc is R2, where 0.1mm ≤ R2 ≤ 2mm.

103. The single-cell battery according to claim 101, characterized in that, The radius of the arc is R2, the thickness of the first plate is L21, and 20%≤R2 / L21≤100%.

104. The single-cell battery according to claim 100, characterized in that, There is an assembly gap between the second plate and the housing.

105. The single-cell battery according to claim 104, characterized in that, The width of the assembly gap is L22, 0.1mm≤L22≤0.5mm.

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