Switching tab, pole piece and naked battery cell

Abstract

The current collector comprises a switching base material, the switching base material comprises a first end and a second end which are oppositely arranged, at least one surface of the first end of the switching base material is provided with a first conductive adhesive layer, and the second end of the switching base material is used for connecting a current collector; the thickness of the first conductive adhesive layer is D1, the thickness of the switching base material is D2, D1 is larger than or equal to 1 micrometer and smaller than or equal to 4 micrometers, and D1 / D2 is larger than or equal to 1 / 8 and smaller than or equal to 1 / 1.5. According to the utility model, the problem that the transfer tabs are easy to separate due to excessive layers of the transfer tabs is solved, and the bonding fixity of the adjacent transfer tabs is improved. The utility model also discloses a pole piece and a naked battery cell.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a switching tab, pole piece and bare electric core. BACKGROUND

[0002] The positive electrode current collector of the secondary battery is usually aluminum foil, and the negative electrode current collector is copper foil, but a scheme for further increasing the mass energy density of lithium battery monomer and reducing the mass of the current collector to reduce the mass of the battery is proposed. Based on this, a composite current collector with a polymer base layer emerged as the times require. The middle layer of this current collector is a low-density polymer layer, and the upper and lower surfaces are uniformly plated with a metal layer. Compared with pure copper foil, the mass can be reduced by 50-80%, thereby improving the mass energy density of the monomer battery.

[0003] Because the middle layer of the composite current collector is an insulating layer, it cannot be directly welded and connected. The prior art usually connects the metal switching tab to the upper and lower metal plating layers of the composite current collector, and then welds the multiple switching tabs with the external tab to form a conduction path. SUMMARY

[0004] The number of switching tab layers is twice the number of composite current collectors. The large number of switching tab layers increases the difficulty of welding with the external tab, making it impossible to completely and firmly weld and prone to separation between the switching tabs, and increasing the contact resistance of the welding. In order to overcome the above-mentioned shortcomings and deficiencies, the purpose of the utility model is to provide a switching tab, a pole piece and a bare electric core, which solve the problem of easy separation between the switching tabs caused by too many switching tab layers, and improve the bonding and fixing property of adjacent switching tabs.

[0005] The purpose of the utility model is achieved by the following technical solutions:

[0006] The utility model provides a kind of switching tab, including switching substrate, the switching substrate includes oppositely arranged first end and second end, at least one side of the first end of the switching substrate is equipped with first conductive adhesive layer, and the second end of the switching substrate is used to connect current collector;The thickness of the first conductive adhesive layer is D1, the thickness of the switching substrate is D2, 1 μm≤D1≤4 μm, 1 / 8≤D1 / D2≤1 / 1.5.

[0007] In an embodiment, the switching substrate is provided with an adhesive layer region, and the first conductive adhesive layer is located in the adhesive layer region. In the length direction of the switching tab, the length of the adhesive layer region is L1, and the length of the switching substrate is L2. 3mm≤L1≤5mm, 1 / 9≤L1 / L2≤1 / 4;And / or, in the thickness direction of the switching tab, the projection area of the first conductive adhesive layer is S1, and the projection area of the switching substrate is S2. 180mm 2 ≤S1≤300mm 21 / 13≤S1 / S2≤1 / 5.

[0008] In an embodiment, in the thickness direction of the adapter tab, the first conductive adhesive layer is one or more of a planar adhesive layer structure, a strip adhesive layer structure, or a dot adhesive layer structure; wherein the dot adhesive layer structure is composed of independently separated adhesive dots.

[0009] The utility model also provides a pole piece, including current collector and the adapter tab as described above, the current collector includes polymer layer and the metal layer which covers the upper and lower surfaces of polymer layer, along the length direction of current collector, adjacent coating area and empty foil area are equipped with on metal layer, the empty foil area with second end fixed connection of adapter substrate.

[0010] In an embodiment, the second end of the adapter substrate and the empty foil area are connected by the second conductive adhesive layer after hot pressing and melting.

[0011] The utility model also provides a bare electric core, including external adapter tab and a plurality of pole pieces as described above, a plurality of pole pieces are sequentially stacked and set up, a plurality of adapter tabs are connected to form adapter tab group through the first conductive adhesive layer, the one end of adapter tab group away from current collector is connected with external adapter tab.

[0012] In an embodiment, the adapter tab on the outer side of the adapter tab group is connected with the external adapter tab through the first conductive adhesive layer after hot pressing and melting.

[0013] In an embodiment, the adapter tab on the outer side of the adapter tab group is connected with the external adapter tab by welding.

[0014] In an embodiment, the first conductive adhesive layer is a dot adhesive layer structure, and the dot adhesive layer structure is composed of a plurality of independently separated adhesive dots.

[0015] In an embodiment, at least one of the two surfaces of the two adjacent adapter tabs in contact is provided with the first conductive adhesive layer.

[0016] The utility model has the advantages that the first conductive adhesive layer is arranged on at least one side of the first end of the adapter substrate, the adapter tab can be directly used in the later tab adapter process, and the adapter tab is electrically connected to the external tab through welding and / or hot pressing; the first conductive adhesive layer on the adapter substrate is molten at the temperature of welding or hot pressing, the adjacent adapter tabs are fixed through bonding, the problem that the middle layer is easily separated due to too many layers of the adapter tab is avoided, and the bonding property of the adjacent adapter tabs is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced the drawings needed to be used in the embodiments, it should be understood, the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other related drawings according to these drawings.

[0018] Figure 1 It is the structural schematic diagram of the adapter tab of the embodiment of the utility model;

[0019] Figure 2 It is the overhead schematic diagram of the first conductive adhesive layer of the adapter tab;

[0020] Figure 3 It is the structural schematic diagram of the tab of an embodiment of the utility model;

[0021] Figure 4 It is the structural schematic diagram of the multiple tabs of Figure 3 in the stacking;

[0022] Figure 5 It is the structural schematic diagram of the tab of another embodiment of the utility model;

[0023] Figure 6 It is the structural schematic diagram of the multiple tabs and the external tab of Figure 4 welded into the bare battery;

[0024] Figure 7 It is the overhead schematic diagram of Figure 6 ;

[0025] Figure 8 It is the front view schematic diagram of the single tab in the bare battery of Figure 6 ;

[0026] In the figure: 100, pole piece; 200, adapter tab group; 1, current collector; 11, polymer layer; 12, metal layer; 121, coating area; 122, empty foil area; 2, adapter tab; 21, adapter substrate; 22, first conductive adhesive layer; 3, active material layer; 4, external tab; 5, adhesive layer area; 51, adhesive printing site; 6, solder printing area; 61, solder printing site; 7, roll solder printing area; 8, second conductive adhesive layer. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application will be described below in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the description of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] In the description of the present application, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0029] The terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the present application is used, and are only for the convenience of description and simplification of the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0030] The terms "first", "second", "third" and the like are only for distinguishing similar attributes of elements, and do not indicate or imply relative importance or a particular order.

[0031] The terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, in addition to including the listed elements, other elements not explicitly listed can also be included.

[0032] The present application provides a kind of adapter tab 2, such as Figures 1 to 6As shown, the adapter substrate 21 includes a first end and a second end arranged oppositely, at least one side of the first end of the adapter substrate 21 is provided with a first conductive adhesive layer 22, the first conductive adhesive layer 22 is used for bonding and conducting two adjacent adapter tabs 2 arranged adjacently; the second end of the adapter substrate 21 is used for connecting the current collector 1; the thickness of the first conductive adhesive layer 22 is D1, the thickness of the adapter substrate 21 is D2, 1 μm≤D1≤4 μm, 1 / 8≤D1 / D2≤1 / 1.5.

[0033] In the embodiment, at least one side of the first end of the adapter substrate 21 is provided with the first conductive adhesive layer 22, the adapter tab 2 can be directly used in the later tab adapter process, and the tab of the current collector 1 is electrically conducted with the external tab 4 by cooperating with welding and / or hot pressing; the first conductive adhesive layer 22 on the adapter substrate 21 is molten at the temperature of welding or hot pressing, the bonding and fixing of the adjacent adapter tabs 2 are realized, and the problem that the intermediate layer is easy to separate due to too many layers of the adapter tabs 2 is avoided, and the bonding and fixing property of the adjacent adapter tabs 2 is improved.

[0034] The first conductive adhesive layer 22 can be arranged on the adapter substrate 21 in single side (one side) or double sides (two sides); from the perspective of saving cost, the first conductive adhesive layer 22 can be arranged in single side; the first conductive adhesive layer 22 is a high-molecular conductive adhesive layer, which is insoluble in electrolyte and can exist stably for a long time; the softening temperature of the first conductive adhesive layer 22 is 60-120 ℃ (which can be molten at the high temperature generated by ultrasonic welding); the adapter substrate 21 is an adapter foil, and the material is copper or aluminum metal; the thickness of the adapter substrate 21 is D2, 4 μm≤D2≤10 μm.

[0035] As an implementation manner, as shown in the drawings, Figure 7 The adapter substrate 21 is provided with an adhesive layer area 5, the first conductive adhesive layer 22 is located in the adhesive layer area 5, in the length direction of the adapter tab 2, the length of the adhesive layer area 5 is L1, the length of the adapter substrate 21 is L2, 3 mm≤L1≤5 mm, 1 / 9≤L1 / L2≤1 / 4; and / or, in the thickness direction D of the adapter tab 2, the projection area of the first conductive adhesive layer 22 is S1, the projection area of the adapter substrate 21 is S2, 180 mm 2 ≤S1≤300 mm 2 , 1 / 13≤S1 / S2≤1 / 5. Specifically, the length direction L of the current collector 1 is consistent with the length direction of the adapter substrate 21, the adapter substrate 21 includes a first end and a second end along the length direction thereof, the first end is connected with the external tab 4, and the second end is connected with the current collector 1; in the width direction of the adapter tab 2, the width of the adhesive layer area 5 is consistent with the width of the adapter substrate 21.

[0036] As an implementation form, in the thickness direction D of the adapter tab 2, the first conductive adhesive layer 22 is one or more of a planar adhesive layer structure (not shown), a strip adhesive layer structure (not shown), or a point adhesive layer structure (as shown in Figure 2 The point adhesive layer structure is preferred; as shown in Figure 7 When later welded with the external tab 4, the point distribution of the first conductive adhesive layer 22 on the adapter substrate 21 can overlap or stagger with the welding print point 61, preferably staggered, because the heat generated by welding melts the first conductive adhesive layer 22, which can fill the non-welding area and conduct the non-welding area, effectively solving the problem of easy separation between the tabs after welding.

[0037] The utility model also provides a pole piece 100, as shown in Figure 3 And Figure 7 The utility model discloses a pole piece 100, as shown in

[0038] As an implementation form, as shown in Figure 3 And Figure 7 The second end of the adapter substrate 21 and the hollow foil area 122 are connected by welding; or as shown in Figure 5 The second end of the adapter substrate 21 and the hollow foil area 122 are connected by the second conductive adhesive layer 8 after hot pressing and melting. Wherein, the second conductive adhesive layer 8 can be arranged on one surface of the second end of the adapter substrate 21, which is in contact with the hollow foil area 122; or the second conductive adhesive layer 8 is arranged on one surface of the hollow foil area 122, which is in contact with the adapter substrate 21.

[0039] Wherein, the second conductive adhesive layer 8 is a high-molecular conductive adhesive layer, which is insoluble in electrolyte and can exist stably for a long time; the softening temperature of the second conductive adhesive layer 8 is 60-120 DEG C; as shown in Figure 7 The size of the adapter tab 2 is consistent with the size of the current collector 1 in the width direction W of the current collector 1.

[0040] The utility model also provides a bare electric core, as shown in Figure 4 And Figure 6As shown, the outer connection tab 4 and a plurality of the above-mentioned tab sheets 100 are included, the plurality of tab sheets 100 are sequentially stacked, the plurality of the connection tabs 2 are connected by the first conductive adhesive layer 22 to form a connection tab group 200, and the connection tab group 200 is connected to the outer connection tab 4 at an end away from the current collector 1.

[0041] As an implementation form, as shown in Figure 6 As shown, one of the connection tabs 2 on the outer side of the connection tab group 200 is bonded and fixed to the outer connection tab 4 by the first conductive adhesive layer 22 after heat pressing and melting, and at the same time, electrical connection is generated.

[0042] As an implementation form, as shown in Figure 6 As shown, one of the connection tabs 2 on the outer side of the connection tab group 200 is bonded and fixed to the outer connection tab 4 by the first conductive adhesive layer 22 after heat pressing and melting, and at the same time, electrical connection is generated. Figure 7 As shown, when the tab sheet 100 is welded to the outer connection tab 4, a welding area 6 is formed, in the length direction L of the current collector 1, the length of the adhesive layer area 5 of the first conductive adhesive layer 22 is L1, the length of the welding area 6 is L3, and L1>L3.

[0043] As an implementation form, as shown in Figure 6 As shown in Figure 7 As shown, the first conductive adhesive layer 22 is a point-shaped adhesive layer structure, which is composed of a plurality of independent separated adhesive points; the first conductive adhesive layer 22 forms an adhesive printing site 51 on the connection substrate 21, that is, one adhesive point corresponds to one adhesive printing site 51, the connection tab group 200 is welded to the outer connection tab 4 to form a welding printing site 61, and the welding printing site 61 and the adhesive printing site 51 are arranged in a staggered manner. It should be noted that the welding printing site 61 can also be arranged in an overlapping manner with the adhesive printing site 51.

[0044] As an implementation form, as shown in Figure 8As shown, at least one of the two surfaces of the two adjacent adapter tabs 2 in contact is provided with the first conductive adhesive layer 22. Specifically, when one surface of the first end of the adapter base material 21 is provided with the first conductive adhesive layer 22, and a plurality of adapter tabs 2 provided with the single-sided first conductive adhesive layer 22 are adhered to each other to form an adapter tab group 200, only one surface of the two surfaces of the two adjacent adapter tabs 2 in contact is provided with the first conductive adhesive layer 22, that is, the surface provided with the first conductive adhesive layer 22 is in contact with the surface of the adjacent adapter tab 2 which is not provided with the first conductive adhesive layer 22; or, when both surfaces of the first end of the adapter base material 21 are provided with the first conductive adhesive layer 22, and a plurality of adapter tabs 2 provided with the double-sided first conductive adhesive layer 22 are adhered to each other to form an adapter tab group 200, both surfaces of the two adjacent adapter tabs 2 in contact are provided with the first conductive adhesive layer 22; of course, the adapter tab 2 provided with the single-sided first conductive adhesive layer 22 and the adapter tab 2 provided with the double-sided first conductive adhesive layer 22 can be mixed and adhered to form an adapter tab group 200. Preferably, the single surface of the adapter base material 21 is provided with the first conductive adhesive layer 22.

[0045] The beneficial effects of the utility model are as follows:

[0046] The utility model provides the adapter tab 2 that first end is provided with the first conductive adhesive layer 22, and the adapter tab 2 can be directly used in the tab adapter process of later period, and is cooperated with the welding and / or hot pressing, and the tab (empty foil area 122) of current collector 1 and external tab 4 are electrically conducted, and the first conductive adhesive layer 22 on the adapter tab 2 melts under the temperature of welding or hot pressing, realizes the bonding of adjacent adapter tabs 2, avoids the problem of adapter tab 2 separation and false welding because of too many layers of adapter tab 2,

[0047] Further, the first conductive adhesive layer 22 is dot-like distributed at one end of the adapter tab 2, the adhesive layer area 5 of the first conductive adhesive layer 22 is coincided with the welding mark area 6, and the glue printing points 51 of the first conductive adhesive layer 22 are distributed staggeredly with the welding mark points 61; the first conductive adhesive layer 22 is molten under the influence of the high temperature of the surrounding welding mark, forms the conductive contact point in the non-welding mark area, enhances the welding firmness between the adapter tabs 2, and reduces the contact resistance between the tabs at the same time.

[0048] The preparation process of the bare battery core of the utility model: the first end of the adapter base material 21 is batch produced to coat the first conductive adhesive layer 22 to obtain the adapter tab 2, the second end of the adapter base material 21 is welded or bonded with the current collector 1 through the second conductive adhesive layer 8 to obtain the pole piece 100, a plurality of pole pieces 100 are stacked, and the end provided with the first conductive adhesive layer 22 is welded together with the external tab 4; the step of coating the first conductive adhesive layer 22 is reduced every time the pole piece is stacked, the process flow is simplified, and the application improvement scheme can realize batch production application without modifying the equipment.

[0049] Embodiment 1

[0050] The current collector 1 is provided with a polymer layer 11 in the middle and metal layers 12 on the upper and lower surfaces;

[0051] The adapter tab 2 comprises an adapter substrate 21, which is an adapter foil made of copper or aluminum metal and has a thickness of 4-10 μm. The width of the adapter foil is consistent with the width of the empty foil area 122 of the current collector 1, and the second end of the adapter foil is roll-welded to the conductive surface (empty foil area 122) of the upper and lower metal layers 12 of the current collector 1 to form the tab 100. The length of the adapter foil is longer than the length of the empty foil area 122 (tab) of the current collector 1, that is, the first end of the adapter foil extends outside the tab of the current collector 1, facilitating subsequent welding connection with the external tab 4.

[0052] The external tab 4 is made of copper or aluminum metal and has a thickness of 0.1-0.4 mm. Along the width direction of the current collector 1, the width of the external tab 4 is W1, and the width of the adapter foil is W2, and 0.8≤W1 / W2≤1. The external tab 4 is welded to the first end (non-roll-welded part) of the adapter tab 2 of the tab 100.

[0053] The first conductive adhesive layer 22 is one or more of an epoxy resin conductive adhesive layer, a phenolic resin conductive adhesive layer, or a polyurethane conductive adhesive layer. The first conductive adhesive layer 22 is dot-shapedly distributed on one side of the first end of the adapter tab 2 of the tab 100. The adhesive layer thickness of the first conductive adhesive layer 22 is 1 μm, and the distribution position of the adhesive layer area 5 is at the welding mark area 6. The distribution width of the adhesive layer area 5 is about 0.5-1.5 mm wider than the width of the welding mark area 6.

[0054] In this embodiment, as shown in Figure 6 and Figure 7 The current collector 1 is provided with multiple layers. The upper and lower surfaces of each single current collector 1 coated with a material are roll-welded with an adapter tab 2. The width of the adapter tab 2 is consistent with the width of the tab (empty foil area 122) of the current collector 1. The overlapping area of the tab of the current collector 1 and the adapter tab 2 is a roll-welded welding mark area 7. One side of the non-roll-welded end (first end) of the adapter tab 2 is dot-coated with a first conductive adhesive layer 22 having a thickness of 1 μm. The position of the adhesive layer area 5 of the dot-coated first conductive adhesive layer 22 on the tab 100 overlaps with the welding mark area 6. The length of the adhesive layer area 5 is L1, and the length of the welding mark area 6 is L3. L1>L3, and the length of the adhesive layer area 5 of the dot-coated first conductive adhesive layer 22 is about 0.5 mm wider than the welding mark area 6 on both sides, that is, L1=0.5+L3+0.5, so that the adhesive layer area 5 of the first conductive adhesive layer 22 can completely cover the welding mark area 6.

[0055] When the ultrasonic welding external tab 4, the first conductive adhesive layer 22 is softened and melted due to high temperature generated by ultrasonic, and after melting, the first conductive adhesive layer 22 will adhere to each other; the welding mark position 61 generated by welding of the external tab 4 and the glue mark position 51 of the first conductive adhesive layer 22 are distributed in a staggered manner, which enhances the adhesion and does not hinder the spot welding of the external tab 4; the molten conductive adhesive layer can fill the non-welding area of the welding position, and the conductive contact surface is also increased, which can reduce the resistance value of the battery cell.

[0056] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the disclosed technical content without departing from the technical solution of the present application, and the equivalent embodiments of equivalent changes are equivalent. Any simple modification, equivalent change and modification of the above embodiments made according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

Claims

1. A tabbing, characterized by, The adapter substrate (21) comprises a first end and a second end arranged oppositely, at least one side of the first end of the adapter substrate (21) is provided with a first conductive adhesive layer (22), and the second end of the adapter substrate (21) is used for connecting the current collector (1); the thickness of the first conductive adhesive layer (22) is D1, the thickness of the adapter substrate (21) is D2, 1 μm≤D1≤4 μm, and 1 / 8≤D1 / D2≤1 / 1.

5.

2. The adapter tab of claim 1, wherein, The adapter substrate (21) is provided with a glue layer area (5), the first conductive glue layer (22) is located in the glue layer area (5), in the length direction of the adapter tab (2), the length of the glue layer area (5) is L1, the length of the adapter substrate (21) is L2, 3mm≤L1≤5mm, 1 / 9≤L1 / L2≤1 / 4; and / or, in the thickness direction (D) of the adapter tab (2), the projection area of the first conductive glue layer (22) is S1, the projection area of the adapter substrate (21) is S2, 180mm 2 ≤S1≤300mm 2 , 1 / 13≤S1 / S2≤1 / 5.

3. The adapter tab of claim 1, wherein, In the projection of the adapter tab (2) in the thickness direction (D), the first conductive adhesive layer (22) is one or more of a planar adhesive layer structure, a strip-shaped adhesive layer structure or a point-shaped adhesive layer structure; wherein the point-shaped adhesive layer structure is composed of a plurality of independently separated adhesive points.

4. A pole piece characterized by, The adapter tab (2) comprises a current collector (1) and a current collector (1) according to any one of claims 1-3; the current collector (1) comprises a polymer layer (11) and a metal layer (12) covering the upper and lower surfaces of the polymer layer (11); along the length direction (L) of the current collector (1), the metal layer (12) is provided with a paint area (121) and a blank foil area (122) adjacent to each other, and the blank foil area (122) is fixedly connected with the second end of the adapter substrate (21).

5. The pole piece of claim 4, wherein The blank foil area (122) and the second end of the adapter substrate (21) are connected by welding; or a second conductive adhesive layer (8) is arranged between the second end of the adapter substrate (21) and the blank foil area (122), and the blank foil area (122) and the second end of the adapter substrate (21) are connected by the second conductive adhesive layer (8) after hot pressing and melting.

6. A bare cell characterized by, The adapter tab (2) comprises an outer tab (4) and a plurality of tabs (100) according to any one of claims 4-5, a plurality of the tabs (100) are arranged in sequence, a plurality of the adapter tabs (2) are connected to form an adapter tab group (200) through the first conductive adhesive layer (22), and one end of the adapter tab group (200) away from the current collector (1) is connected with the outer tab (4).

7. The bare cell of claim 6, wherein, One of the adapter tabs (2) located outside the adapter tab group (200) is connected with the outer tab (4) through the first conductive adhesive layer (22) after hot pressing and melting.

8. The bare cell of claim 6, wherein, One of the adapter tabs (2) located outside the adapter tab group (200) is connected with the outer tab (4) by welding.

9. The bare cell of claim 8, wherein, The first conductive adhesive layer (22) is a point-shaped adhesive layer structure composed of a plurality of independently separated adhesive points; the first conductive adhesive layer (22) forms a printing point (51) on the adapter substrate (21), the adapter tab group (200) and the outer tab (4) are welded to form a welding point (61), and the welding point (61) and the printing point (51) are overlapped or misaligned.

10. The bare cell of claim 6, wherein, At least one of the two surfaces of the two adjacent adapter tabs (2) in contact is provided with the first conductive adhesive layer (22).

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