Battery cell and battery

Abstract

The utility model discloses a battery cell and a battery, which are applied to the technical field of batteries. According to the utility model, the diaphragm layer between the adjacent tabs is punctured by adding the conductive structure with the convex structure to realize interlayer conduction, and when the structure is subsequently welded, the welded tabs can be heated to a local melting state by utilizing resistance heat generated by the convex structure, so that the welding is realized. The structure is simple in process, one-time welding forming can be achieved, and compared with a conventional welding structure, the welding effect is better; meanwhile, the diaphragm layer is melted in the subsequent welding process, so that the tabs are connected, the resistance value of the welding area is small, good conductivity of the welding area can be ensured, and the conductivity is better than that of a conventional welding structure.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery. Background Art

[0002] At present, the commonly used welding processes for multi-electrode tab structures are ultrasonic welding, laser welding, resistance welding, etc. The welding structures of these welding methods are relatively similar. When welding multiple tabs together, it is usually necessary to perform pre-welding before final welding, which is a complex process. Moreover, the above welding processes are not effective when welding multi-electrode tab structures with a diaphragm layer in the middle. Phenomena such as cold welding and hot spots are prone to occur. In addition, the presence of the diaphragm layer leads to poor electrical conductivity in the welding area. Therefore, how to improve the welding effect and electrical conductivity of multi-electrode tab structures with a diaphragm layer is a technical problem that technicians in this field currently need to solve. Utility Model Content

[0003] In view of this, the purpose of the present invention is to provide a battery cell and a battery for solving the problems of poor welding effect and poor conductivity in welding of a multi-electrode tab structure with a diaphragm layer.

[0004] To solve the above technical problems, the present invention provides a battery cell; the battery cell includes a first electrode piece, a second electrode piece, and a separator layer located between the first electrode piece and the second electrode piece; the first electrode piece includes a first current collector and a first active material layer provided on a surface of the first current collector, and at least one first electrode tab extending outward from one side of the first current collector;

[0005] The diaphragm layer includes a first portion extending out of the first active material layer;

[0006] The first portion of the diaphragm layer and the first electrode tab are alternately arranged along a first direction to form a first electrode tab portion;

[0007] Also includes:

[0008] Conductive structure; the conductive structure includes a protruding structure, and the protruding structure at least partially penetrates the first electrode portion along the first direction.

[0009] Optionally, the first electrode tab includes a first connection region in contact with the protruding structure; the first electrode tab and the protruding structure are connected in the first connection region.

[0010] Optionally, the first tab portion includes a second connection region surrounding the protruding structure; and the first tabs adjacent to each other along the first direction are connected within the second connection region.

[0011] Optionally, the conductive structure includes at least two protruding structures; and the first tabs adjacent to each other along the first direction are connected between adjacent protruding structures.

[0012] Optionally, the resistance between the first tabs adjacent to each other along the first direction is 0.5 mΩ-1000 mΩ, inclusive;

[0013] And / or, the internal resistance of all the first tabs as a whole is 1 mΩ-1000 mΩ, including the values at both ends.

[0014] Optionally, the diaphragm layer includes a carbonized region; the diameter of the carbonized region is 5 mm to 10 mm, including both ends;

[0015] And / or, the diaphragm layer includes a contraction area; the diameter of the contraction area is 5 mm-10 mm, including the values at both ends.

[0016] Optionally, the conductive structure includes a second pole tab; the protruding structure is provided on a surface of the second pole tab; and the second pole tab is provided on a first side of the first pole tab portion along the first direction.

[0017] Optionally, a protective sheet is provided on the second side of the first tab portion along the first direction.

[0018] Optionally, the protective sheet has a thickness of 0.1 mm to 5 mm, inclusive;

[0019] and / or, a ratio of the area of the protective sheet to the area occupied by the protruding structure is 1.1-5, inclusive;

[0020] And / or, the welding adhesion between the protection sheet and the first tab portion is 0-0.5N, including the value at the right end.

[0021] Optionally, the second electrode tab includes a first portion and a second portion along the second direction; the protruding structure is provided on a side surface of the first portion; and a first adhesive layer is provided on both side surfaces of the second portion.

[0022] Optionally, the first adhesive layer is a PP adhesive layer;

[0023] and / or, the distance between the first adhesive layer and the protruding structure is 0.1 mm to 1 mm, inclusive;

[0024] and / or, the width of the first adhesive layer is 1 mm to 10 mm, inclusive;

[0025] and / or, the length of the first adhesive layer is 5 mm to 20 mm, inclusive;

[0026] and / or, the thickness of the first adhesive layer is 0.005 mm to 1 mm, inclusive;

[0027] And / or, a distance between an edge of a side of the second portion facing away from the first portion and the protruding structure is 5 mm to 20 mm, including both ends.

[0028] Optionally, the conductive structure includes a second tab and a transfer plate; the transfer plate includes a base and the protruding structure provided on a surface of the base;

[0029] The second tab is disposed on a first side of the first tab portion along the first direction, and the adapter is disposed on a second side of the first tab portion along the first direction.

[0030] Optionally, a protective sheet is provided on a surface of the adapter sheet facing away from the first tab portion.

[0031] Optionally, the adapter plate is a metal adapter plate;

[0032] and / or, the base has a thickness of 0.1 mm to 3 mm, inclusive;

[0033] And / or, the area of the adapter is smaller than the area of the first tab portion;

[0034] and / or, the length of the base is smaller than the length of the first tab;

[0035] And / or, the width of the base is smaller than the width of the first tab;

[0036] And / or, the protruding structure is a conical structure or a truncated cone structure;

[0037] The diameter of the truncated cone structure is 0.1 mm to 3 mm, including the values at both ends;

[0038] And / or, the angle of the truncated cone structure is 30° to 60°, inclusive;

[0039] And / or, the height of the truncated cone structure is 0.05 mm to 0.3 mm, inclusive;

[0040] And / or, the number of the frustum structures in the second direction is 1 to 5, inclusive;

[0041] And / or, the number of the frustum structures in the third direction is 1 to 30, inclusive;

[0042] And / or, the spacing between adjacent frustum structures is 0.1 mm to 3 mm, including the values at both ends.

[0043] Optionally, the welding area between the first tab portion and the second tab is provided with a weld mark; the weld mark corresponds to the protruding structure one-to-one.

[0044] Optionally, the ratio of the diameter of the weld mark to the diameter of the protruding structure is 1 to 1.2, including both ends.

[0045] Optionally, the battery cell is a multi-electrode winding core; each of the first pole pieces of the multi-electrode winding core includes a plurality of first pole tabs;

[0046] Alternatively, the battery cell is a multi-tab stacked core; each first pole piece of the multi-tab stacked core includes one first pole tab.

[0047] In order to solve the above technical problems, the present invention also provides a battery, including: the battery cell described above.

[0048] It can be seen that the utility model achieves interlayer conductivity by adding a conductive structure with a raised structure to pierce the diaphragm layer between adjacent tabs. When the structure is subsequently welded, the resistance heat generated by the raised structure can be used to heat the tabs to a partially molten state, thereby achieving welding. This structural process is simple and can achieve one-time welding and better welding effect than conventional welding structures. At the same time, the diaphragm layer will melt during the subsequent welding process, so that the tabs can be connected. The resistance value of the welding area is small, which can ensure good conductivity of the welding area, and has better conductivity than conventional welding structures. The utility model also provides a battery that uses the above-mentioned battery cell and also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0050] Figure 1 A partial schematic diagram of a welding structure provided by an embodiment of the present utility model;

[0051] Figure 2 A partial physical diagram of a welding structure provided in an embodiment of the utility model;

[0052] Figure 3 A schematic diagram of the shrinkage of a diaphragm layer provided in an embodiment of the present utility model;

[0053] Figure 4A partial schematic diagram of a welding structure provided by an embodiment of the present utility model;

[0054] Figure 5 A three-dimensional diagram of a welding structure provided by an embodiment of the present utility model;

[0055] Figure 6 A schematic diagram of a first conductive structure provided by an embodiment of the present utility model;

[0056] Figure 7 A top view of an adapter provided in an embodiment of the present utility model;

[0057] Figure 8 A side view of an adapter provided in an embodiment of the present utility model;

[0058] Figure 9 A schematic diagram of the area occupied by a protruding structure provided in an embodiment of the present utility model;

[0059] Figure 10 A schematic diagram of a second conductive structure provided by an embodiment of the present utility model;

[0060] Figure 11 A schematic structural diagram of a welding seal provided in an embodiment of the present utility model;

[0061] Figure 12 A schematic diagram of a third conductive structure provided by an embodiment of the present utility model;

[0062] Figure 13 A side view of a second electrode tab provided in an embodiment of the present utility model;

[0063] Figure 14 A top view of a second electrode tab provided in an embodiment of the present utility model;

[0064] Figure 15 A schematic structural diagram of the first diaphragm layer provided in an embodiment of the present utility model;

[0065] Figure 16 A schematic structural diagram of a second diaphragm layer provided in an embodiment of the present utility model;

[0066] Figure 17 This is a schematic structural diagram of the third diaphragm layer provided in an embodiment of the present utility model.

[0067] The following are the descriptions of the reference numerals:

[0068] 01-first tab part; 1-first tab; 2-diaphragm layer; 21-substrate; 22-ceramic layer; 23-second adhesive layer; 3-convex structure; 31-truncated cone structure; 4-adapter; 5-base; 6-protective sheet; 7-second tab; 8-first adhesive layer; 9-weld stamp; 10-weld head; 11-weld seat;

[0069] T-thickness of the first tab; h1-length of the first tab; h2-width of the first tab;

[0070] t-thickness of the diaphragm layer; H1-length of the diaphragm layer;

[0071] L1-base thickness; L3-base length; L4-base width;

[0072] A-diameter of the frustum structure; ϴ-angle of the frustum structure; L2-height of the frustum structure; B-distance between adjacent frustum structures;

[0073] V1 - distance between the first adhesive layer and the protruding structure; V2 - width of the first adhesive layer; V3 - thickness of the first adhesive layer; V4 - distance between the edge of the second portion facing away from the first portion and the protruding structure; V5 - length of the first adhesive layer. DETAILED DESCRIPTION

[0074] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0075] Please refer to Figures 1 to 17 , an embodiment of the present invention provides a battery cell; the battery cell includes a first electrode piece, a second electrode piece, and a diaphragm layer 2 located between the first electrode piece and the second electrode piece; the first electrode piece includes a first current collector and a first active material layer arranged on the surface of the first current collector and at least one first electrode ear 1 extending outward from one side of the first current collector; characterized in that,

[0076] The diaphragm layer 2 includes a first portion extending out of the first active material layer;

[0077] The first portion of the diaphragm layer 2 and the first tab are alternately arranged along the first direction to form a first tab portion 01;

[0078] Also includes:

[0079] Conductive structure; the conductive structure includes a protruding structure 3, which at least partially penetrates the first electrode tab portion 01 along the first direction.

[0080] It should be noted that the first direction in this embodiment represents the thickness direction, the second direction represents the length direction, and the third direction represents the width direction. In this embodiment, one of the first and second pole pieces represents the positive pole piece and the other represents the negative pole piece.

[0081] In this embodiment, the first current collector may have the first active material layer provided on both surfaces thereof, or may have the first active material layer provided on one surface thereof.

[0082] This embodiment does not limit the specific type of battery cell. For example, the battery cell may be a multi-pole winding core; each first pole piece of the multi-pole winding core may include multiple first pole pieces 1; or, the battery cell may be a multi-pole stacked core; each first pole piece of the multi-pole stacked core may include one first pole piece 1.

[0083] After welding the battery cell in this embodiment, a welded structure can be obtained, in which the first pole tab portion 01 may include a first connection region in contact with the raised structure 3; within the first connection region, the first pole tab 1 and the raised structure 3 are connected. The first pole tab portion 01 may also include a second connection region surrounding the raised structure 3; within the second connection region, adjacent first pole tabs 1 along the first direction are connected. It should be noted that after welding is completed, in the region where the first pole tab 1 and the raised structure 3 are in contact, the first pole tab 1 will be connected to the raised structure 3, and this connection region is the first connection region; because the raised structure 3 will melt the diaphragm layer 2 within the portion surrounding the raised structure 3, adjacent first pole tabs 1 within this range can be directly connected, and this connection region is the second connection region.

[0084] This embodiment does not limit the specific number of raised structures 3. For example, the conductive structure may include one raised structure 3; the conductive structure may also include at least two raised structures 3. In this embodiment, when the conductive structure includes at least two raised structures 3, adjacent first electrode tabs 1 along the first direction are connected between adjacent raised structures 3. That is, a first electrode tab portion 01 in which multiple first electrode tabs 1 are interconnected is formed between adjacent raised structures 3. All first electrode tabs 1 are connected to the raised structures 3. The conductive structure and the first electrode tab portion 01 form a riveted structure as a whole, which has greater welding strength than conventional welded structures.

[0085] The structural cross-section after welding is completed is as follows Figure 1 and Figure 2 As shown, the diaphragm layer 2 in the partial area surrounding the protruding structure 3 has been completely melted to form a carbonized area, and the melted part of the first electrode tab 1 is squeezed between adjacent protruding structures 3 to form a frustum-shaped molten pool, so that the first electrode tabs 1 adjacent to each other along the first direction are connected. Figure 1 and Figure 2 Due to the melting, decomposition, and carbonization of the diaphragm layer 2, the diaphragm layer 2 itself has a high resistance. However, the conductivity is improved after carbonization, which significantly improves the conductivity of the overall welded structure. This embodiment does not limit the specific range of the carbonized area included in the diaphragm layer 2. For example, the diameter of the carbonized area can be 5 mm to 10 mm, inclusive.

[0086] After welding, the structure has heat-affected zone, such as Figure 3 As shown, the diaphragm layer 2 shrinks from the inside outward due to heat, forming a shrinkage area. This shrinkage prevents the diaphragm layer 2 from melting and adhering to the welding head 10 or welding base 11 on the side thereof during welding. This embodiment does not limit the specific range of the shrinkage area included in the diaphragm layer 2. For example, the diameter of the shrinkage area can be 5 mm to 10 mm, inclusive.

[0087] After welding is completed, the diaphragm melts, so that the first tabs 1 adjacent to each other along the first direction can be electrically connected. This embodiment does not limit the specific resistance between the first tabs 1 adjacent to each other along the first direction. For example, the resistance between the first tabs 1 adjacent to each other along the first direction (including Figure 4 The resistance between any adjacent first tabs 1 in the embodiment may be 0.5 mΩ to 1000 mΩ, inclusive. This embodiment is not limited to a specific internal resistance of the first tabs 1 as a whole. For example, the internal resistance of all first tabs 1 as a whole may be 1 mΩ to 1000 mΩ, inclusive.

[0088] This embodiment does not limit the specific structure of the conductive structure, and for example, it can be the following three structures:

[0089] (1) If Figure 5 and Figure 6 As shown, the conductive structure may include a transfer plate 4; the transfer plate 4 may include a base 5 and a protruding structure 3 arranged on the surface of the base 5; the transfer plate 4 may be arranged on the first side of the first tab portion 01 along the first direction.

[0090] This embodiment does not limit the specific type of adapter plate 4. The adapter plate 4 can be, but is not limited to, a metal adapter plate 4. This embodiment does not limit the specific type of metal adapter plate 4. The adapter plate 4 can be made of any metal material. This embodiment does not limit the specific size of the adapter plate 4. The area of the adapter plate 4 can be, but is not limited to, smaller than the area of the first tab portion 01.

[0091] This embodiment does not limit the specific thickness of the base 5. For example, the thickness L1 of the base 5 can be between 0.1 mm and 3 mm, inclusive. This embodiment does not limit the specific length of the base 5. For example, the base length L3 can be less than the length h1 of the first tab, and the base width L4 can be less than the width h2 of the first tab 1. In other words, the area of the adapter 4 is smaller than the area of the first tab 1.

[0092] like Figure 7 and Figure 8 As shown, the present embodiment does not limit the specific shape of the protruding structure 3. For example, the protruding structure 3 may be a conical structure or a truncated cone structure 31. The present embodiment does not limit the specific diameter of the truncated cone structure 31. For example, the diameter A of the truncated cone structure 31 may be 0.1 mm to 3 mm, including the values at both ends. The truncated cone structure 31 includes a first circular bottom surface in contact with the base 5, and a second circular bottom surface not in contact with the base 5. The diameter of the first circular bottom surface is larger than that of the second circular bottom surface. In the present embodiment, the diameter A of the truncated cone structure refers to the diameter of the first circular bottom surface. The present embodiment does not limit the specific angle of the truncated cone structure 31. For example, the angle ϴ of the truncated cone structure may be 30° to 60°, including the values at both ends. The angle ϴ of the truncated cone structure refers to the inclination angle of the side of the truncated cone structure 31. The present embodiment does not limit the specific height of the truncated cone structure 31. For example, the height L2 of the truncated cone structure may be 0.05 mm to 0.3 mm, including the values at both ends. This embodiment does not limit the specific number of frustum structures 31. For example, the number of frustum structures 31 in the second direction can be 1 to 5, inclusive; and / or the number of frustum structures 31 in the third direction can be 1 to 30, inclusive. This embodiment does not limit the specific spacing between adjacent frustum structures 31. For example, the spacing B between adjacent frustum structures can be 0.1 mm to 3 mm, inclusive. The specific diameter, height, and number of the conical structures in this embodiment can refer to the frustum structure 31 and will not be repeated here.

[0093] Furthermore, in this embodiment, a protective sheet 6 may be provided on the second side of the first tab portion 01 along the first direction. The provision of the protective sheet 6 can prevent the first tab portion 01 from adhering to the welding head 10 or welding seat 11 in the welding device during welding, thereby avoiding tearing of the first tab 1 or the diaphragm layer 2 to generate burrs or damage.

[0094] This embodiment does not limit the specific thickness of the protective sheet 6. For example, the thickness of the protective sheet 6 can be 0.1 mm to 5 mm, including both ends. This embodiment does not limit the specific area of the protective sheet 6. The area of the protective sheet 6 must be larger than the area occupied by the protruding structure 3. For example, the ratio of the area of the protective sheet 6 to the area occupied by the protruding structure 3 can be 1.1 to 5, including both ends. It should be noted that when the conductive structure includes at least two protruding structures 3, the area occupied by the protruding structure 3 is Figure 9 The dashed box area shown surrounds all raised structures 3. This embodiment does not limit the specific welding adhesion of the protective sheet 6. For example, the welding adhesion between the protective sheet 6 and the first tab portion 01 can be 0-0.5N, including the value on the right end. The specific value of the welding adhesion can be achieved by adjusting it during the welding process. There is almost no welding effect between the protective sheet 6 and the first tab portion 01, and it can be easily removed. This structure can prevent the first tab portion 01 from adhering to the welding head 10 or welding base 11 in the welding device.

[0095] (2) If Figure 10 As shown, the conductive structure may include a second tab 7 and a transfer plate 4; the transfer plate 4 may include a base 5 and a protruding structure 3 disposed on a surface of the base 5; the second tab 7 may be disposed on a first side of the first tab portion 01 along a first direction, and the transfer plate 4 may be disposed on a second side of the first tab portion 01 along the first direction. It should be noted that in this embodiment, the first tab 1 is a soft tab, and the second tab 7 is a hard tab. By adding a hard tab connected to the soft tab, the hard tab has a stronger bending resistance than the soft tab due to the characteristics of its material and structure, thereby enhancing the stability of the tab structure.

[0096] This embodiment does not limit the specific parameters of the adapter plate 4 in the second conductive structure. You may refer to the above-mentioned definition of the adapter plate 4 in the first conductive structure, which will not be repeated here.

[0097] Furthermore, in this embodiment, a protective sheet 6 may be provided on the side of the adapter plate 4 facing away from the first tab portion 01. The protective sheet 6 can prevent the adapter plate 4 from adhering to the welding head 10 or welding seat 11 of the welding device during welding, thereby avoiding burrs caused by tearing or damage to the weld mark 9, which may result in poor welding results.

[0098] This embodiment does not limit the specific parameters of the protection sheet 6 in the second conductive structure. You may refer to the above definition of the protection sheet 6 in the first conductive structure, which will not be repeated here.

[0099] like Figure 11 As shown, in this embodiment, a weld mark 9 is provided at the welding area between the first tab portion 01 and the second tab 7; the weld mark 9 corresponds one-to-one with the protrusion structure 3 and is formed at the welding area where the protrusion structure 3 and the second tab 7 contact. This embodiment does not limit the specific diameter of the weld mark 9; the ratio of the diameter of the weld mark 9 to the diameter of the protrusion structure 3 can be 1 to 1.2, inclusive.

[0100] (3) If Figure 12 As shown, the conductive structure may include a second electrode tab 7 ; a protrusion structure 3 is provided on a surface of the second electrode tab 7 ; and the second electrode tab 7 is provided on a first side of the first electrode tab portion 01 along a first direction.

[0101] This embodiment does not limit the specific parameters of the protruding structure 3 in the third conductive structure. You may refer to the above definition of the protruding structure 3 in the first conductive structure, which will not be repeated here.

[0102] Furthermore, in this embodiment, a protective sheet 6 may be provided on the second side of the first tab portion 01 along the first direction. The provision of the protective sheet 6 can prevent the first tab portion 01 from adhering to the welding head 10 or welding seat 11 in the welding device during welding, thereby avoiding tearing of the first tab 1 or the diaphragm layer 2 to generate burrs or damage.

[0103] This embodiment does not limit the specific parameters of the protection sheet 6 in the third conductive structure. You may refer to the above definition of the protection sheet 6 in the first conductive structure, which will not be repeated here.

[0104] It should be noted that the second tab 7 is longer than the adapter plate 4. In this embodiment, the second tab 7 may include a first portion and a second portion along the second direction. The protrusion 3 may be provided on one side of the first portion. The first adhesive layer 8 may be provided on both sides of the second portion. The first adhesive layer 8 protects the second tab 7.

[0105] like Figure 13 and 14 As shown, this embodiment does not limit the specific type of the first adhesive layer 8. The first adhesive layer 8 can be, but is not limited to, a PP (polypropylene) adhesive layer. This embodiment does not limit the specific distance between the first adhesive layer 8 and the protruding structure 3. For example, the distance V1 between the first adhesive layer and the protruding structure is 0.1 mm to 1 mm, inclusive. This embodiment does not limit the specific width of the first adhesive layer 8. For example, the width V2 of the first adhesive layer is 1 mm to 10 mm, inclusive. This embodiment does not limit the specific length of the first adhesive layer 8. For example, the length V5 of the first adhesive layer is 5 mm to 20 mm, inclusive. This embodiment does not limit the specific thickness of the first adhesive layer 8. For example, the thickness V3 of the first adhesive layer is 0.005 mm to 1 mm, inclusive.

[0106] This embodiment does not limit the specific distance between the edge of the second portion facing away from the first portion and the protruding structure 3 . For example, the distance V4 between the edge of the second portion facing away from the first portion and the protruding structure may be 5 mm to 20 mm, including both ends.

[0107] This embodiment does not limit the specific type of the first electrode tab 1. The first electrode tab 1 can be, but is not limited to, a metal electrode tab. Furthermore, the first electrode tab 1 can be a copper electrode tab or an aluminum electrode tab. This embodiment does not limit the specific thickness of the first electrode tab 1. For example, the thickness T of the first electrode tab can range from 1 μm to 20 μm, inclusive. This embodiment does not limit the specific dimensions of the first electrode tab 1. For example, the width h2 of the first electrode tab can be less than or equal to the width of the diaphragm layer 2, and the length h1 of the first electrode tab can be less than or equal to the length H1 of the diaphragm layer. This embodiment does not limit the specific number of first electrode tabs 1. For example, the number of first electrode tabs 1 can range from 2 to 50, inclusive.

[0108] This embodiment does not limit the type of the outermost layer of the first electrode tab portion 01 . For example, the outermost layer of the first electrode tab portion 01 may be the first electrode tab 1 or the separator layer 2 .

[0109] This embodiment does not limit the specific thickness of the diaphragm layer 2 . For example, the thickness t of the diaphragm layer may be 1 μm to 20 μm, including both ends.

[0110] This embodiment does not limit the specific number of separator layers 2 between adjacent first electrode tabs 1 . For example, one or more separator layers 2 may be included between adjacent first electrode tabs 1 .

[0111] This embodiment does not limit the specific type of the diaphragm layer 2. For example, the following three types of diaphragm layers 2 may be used:

[0112] (1) If Figure 15 As shown, the diaphragm layer 2 may include a substrate 21; the diaphragm layer 2 of such a single-layer structure is a non-adhesive diaphragm;

[0113] (2) If Figure 16 As shown, the diaphragm layer 2 may include a second adhesive layer 23, a ceramic layer 22, a substrate 21, a ceramic layer 22, and a second adhesive layer 23 arranged in sequence along a first direction; the diaphragm layer 2 of this multi-layer structure is a single-sided ceramic adhesive diaphragm;

[0114] (3) If Figure 17 As shown, the diaphragm layer 2 may include a second adhesive layer 23, a ceramic layer 22, a substrate 21 and a second adhesive layer 23 arranged in sequence along a first direction; the diaphragm layer 2 of such a multi-layer structure is an adhesive diaphragm with double-sided ceramics.

[0115] This embodiment does not limit the specific thickness of the substrate 21. For example, the thickness of the substrate 21 can be 3 μm to 10 μm, inclusive. This embodiment does not limit the specific type of the substrate 21. For example, the substrate 21 can be a PP substrate 21 or a PE (Polyethylene) substrate 21.

[0116] This embodiment does not limit the specific thickness of the ceramic layer 22. For example, the thickness of the ceramic layer 22 can be 0.5 μm to 5 μm, including both ends. This embodiment does not limit the specific type of the ceramic layer 22. For example, the ceramic layer 22 can be an inorganic ceramic layer 22 or an aluminum oxide ceramic layer 22.

[0117] The present embodiment does not limit the specific thickness of the second adhesive layer 23 . For example, the thickness of the second adhesive layer 23 may be 0.5 μm-5 μm, inclusive. The present embodiment does not limit the specific type of the second adhesive layer 23 . For example, the second adhesive layer 23 may be a PVDF (Polyvinylidene Fluoride) adhesive layer.

[0118] Based on the above embodiments, the present invention achieves interlayer conductivity by adding a conductive structure with a raised structure to pierce the diaphragm layer between adjacent tabs. When the structure is subsequently welded, the resistance heat generated by the raised structure can be used to heat the tabs to a partially molten state, thereby achieving welding. This structure is simple to process and can be welded in one go, resulting in better welding results than conventional welding structures. At the same time, during the subsequent welding process, the diaphragm layer will melt, allowing the tabs to be connected. The resistance value of the welding area is relatively low, ensuring good conductivity in the welding area, which is better than conventional welding structures.

[0119] A battery provided by an embodiment of the present invention may include: the above-mentioned battery cell.

[0120] The battery in this embodiment may be, but is not limited to, a lithium-ion battery.

[0121] Based on the above embodiments, the present invention adopts the above battery cells and also has the above beneficial effects.

[0122] In order to make the present invention easier to understand, the following takes the stacking structure of the metal layer and the diaphragm layer as an example and combines the specific welding process of the stacking structure to illustrate the welding structure provided by the embodiment of the present invention.

[0123] use Figure 6 The specific welding process of the conductive structure shown is as follows:

[0124] (1) Take an appropriate number of metal layers and diaphragm layers 2, cut them according to the actual size requirements, and then cross-stack the metal layers and diaphragm layers 2 on the welding station;

[0125] (2) shaping and smoothing the above metal layer, and placing a protective sheet 6 on top of the stacked structure;

[0126] (3) Use the metal protrusion structure 3 on the adapter plate 4 to pierce the stacked structure and stack the adapter plate 4 under the stacked structure;

[0127] (4) The welding head 10 uses a first electrode and the welding seat 11 uses a second electrode. The welding head 10 and the welding seat 11 are pressed down to apply welding pressure, so that the welding head 10 and the welding seat 11 form a current loop with the metal layer to be welded, and the metal layer to be welded is melted to form a molten pool to achieve welding. The protective sheet 6 can be retained or peeled off.

[0128] use Figure 10 The specific welding process of the conductive structure shown is as follows:

[0129] (1) Take an appropriate number of metal layers and diaphragm layers 2, cut them according to the actual size requirements, and then cross-stack the metal layers and diaphragm layers 2 on the welding station;

[0130] (2) Shaping and smoothing the above metal layer;

[0131] (3) Use the metal protrusion structure 3 on the adapter plate 4 to pierce the stacked structure and stack the adapter plate 4 under the stacked structure; place a protective sheet 6 under the adapter plate 4;

[0132] (4) The welding head 10 uses a first electrode and the welding seat 11 uses a second electrode. The welding head 10 and the welding seat 11 are pressed down to apply welding pressure, so that the welding head 10 and the welding seat 11 form a current loop with the metal layer to be welded, and the metal layer to be welded is melted to form a molten pool to achieve welding. The protective sheet 6 can be retained or peeled off.

[0133] use Figure 12 The specific welding process of the conductive structure shown is as follows:

[0134] (1) Take an appropriate number of metal layers and diaphragm layers 2, cut them according to the actual size requirements, and then cross-stack the metal layers and diaphragm layers 2 on the welding station;

[0135] (2) Shaping and smoothing the above metal layer, and placing a protective sheet 6 under the stacked structure;

[0136] (3) Using the metal protrusion structure 3 on the second tab 7 to pierce the stacked structure and stacking the second tab 7 on top of the stacked structure;

[0137] (4) The welding head 10 uses a first electrode and the welding seat 11 uses a second electrode. The welding head 10 and the welding seat 11 are pressed down to apply welding pressure, so that the welding head 10 and the welding seat 11 form a current loop with the metal layer to be welded, and the metal layer to be welded is melted to form a molten pool to achieve welding. The protective sheet 6 can be retained or peeled off.

[0138] The above is a detailed introduction to a welding structure and a battery provided by the present invention. For those skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A battery cell; the battery cell comprises a first electrode sheet, a second electrode sheet, and a separator layer located between the first electrode sheet and the second electrode sheet; the first electrode sheet comprises a first current collector, a first active material layer disposed on a surface of the first current collector, and at least one first electrode tab extending outward from one side of the first current collector; characterized in that: The diaphragm layer includes a first portion extending out of the first active material layer; The first portion of the diaphragm layer and the first electrode tab are alternately arranged along a first direction to form a first electrode tab portion; Also includes: Conductive structure; The conductive structure includes a protruding structure, and the protruding structure at least partially penetrates the first tab portion along the first direction.

2. The battery cell according to claim 1, characterized in that The first tab portion includes a first connection region in contact with the protruding structure; the first tab and the protruding structure are connected in the first connection region.

3. The battery cell according to claim 1, characterized in that The first tab portion includes a second connection region surrounding the protruding structure; and the first tabs adjacent to each other along the first direction are connected in the second connection region.

4. The battery cell according to claim 3, characterized in that The conductive structure includes at least two protruding structures; and the first tabs adjacent to each other along the first direction are connected between adjacent protruding structures.

5. The battery cell according to claim 4, characterized in that: The resistance between the first tabs adjacent to each other along the first direction is 0.5 mΩ to 1000 mΩ, inclusive; And / or, the internal resistance of all the first tabs as a whole is 1 mΩ-1000 mΩ, including the values at both ends.

6. The battery cell according to claim 1, characterized in that The diaphragm layer includes a carbonized region; the diameter of the carbonized region is 5 mm to 10 mm, including both ends; And / or, the diaphragm layer includes a contraction area, and the diameter of the contraction area is 5 mm-10 mm, including the values at both ends.

7. The battery cell according to claim 1, characterized in that The conductive structure includes a second electrode tab; the protruding structure is provided on a surface of the second electrode tab; and the second electrode tab is provided on a first side of the first electrode tab portion along the first direction.

8. The battery cell according to claim 7, characterized in that: A protection sheet is provided on the second side of the first tab portion along the first direction.

9. The battery cell according to claim 8, characterized in that The thickness of the protective sheet is 0.1 mm to 5 mm, including both ends; and / or, a ratio of the area of the protective sheet to the area occupied by the protruding structure is 1.1-5, inclusive; And / or, the welding adhesion between the protection sheet and the first tab portion is 0-0.5N, including the value at the right end.

10. The battery cell according to claim 7, characterized in that: The second tab includes a first portion and a second portion along a second direction; the protruding structure is provided on a side surface of the first portion; and a first adhesive layer is provided on both side surfaces of the second portion.

11. The battery cell according to claim 10, characterized in that: The first adhesive layer is a PP adhesive layer; and / or, the distance between the first adhesive layer and the protruding structure is 0.1 mm to 1 mm, inclusive; and / or, the width of the first adhesive layer is 1 mm to 10 mm, inclusive; and / or, the length of the first adhesive layer is 5 mm to 20 mm, inclusive; and / or, the thickness of the first adhesive layer is 0.005 mm to 1 mm, inclusive; And / or, a distance between an edge of a side of the second portion facing away from the first portion and the protruding structure is 5 mm to 20 mm, including both ends.

12. The battery cell according to claim 1, characterized in that The conductive structure includes a second tab and a transfer plate; the transfer plate includes a base and the protruding structure provided on the surface of the base; The second tab is disposed on a first side of the first tab portion along the first direction, and the adapter is disposed on a second side of the first tab portion along the first direction.

13. The battery cell according to claim 12, characterized in that: A protective sheet is provided on a surface of the adapter sheet that is away from the first tab portion.

14. The battery cell according to claim 12, characterized in that: The adapter is a metal adapter; and / or, the base has a thickness of 0.1 mm to 3 mm, inclusive; And / or, the area of the adapter is smaller than the area of the first tab portion; and / or, the length of the base is smaller than the length of the first tab; And / or, the width of the base is smaller than the width of the first tab; And / or, the protruding structure is a conical structure or a truncated cone structure; The diameter of the truncated cone structure is 0.1 mm to 3 mm, including the values at both ends; And / or, the angle of the truncated cone structure is 30° to 60°, inclusive; And / or, the height of the truncated cone structure is 0.05 mm to 0.3 mm, inclusive; And / or, the number of the frustum structures in the second direction is 1 to 5, inclusive; And / or, the number of the frustum structures in the third direction is 1 to 30, inclusive; And / or, the spacing between adjacent frustum structures is 0.1 mm to 3 mm, including the values at both ends.

15. The battery cell according to claim 12, characterized in that: The welding area between the first tab portion and the second tab is provided with a welding mark; the welding mark corresponds to the protruding structure one by one.

16. The battery cell according to claim 15, characterized in that The ratio of the diameter of the weld mark to the diameter of the protruding structure is 1 to 1.2, inclusive.

17. The battery cell according to claim 1, characterized in that The battery core is a multi-electrode winding core; each of the first pole pieces of the multi-electrode winding core includes a plurality of first pole tabs; Alternatively, the battery cell is a multi-tab stacked core; each first pole piece of the multi-tab stacked core includes one first pole tab.

18. A battery, characterized in that: include: The battery cell according to any one of claims 1 to 17.

Images