Pole piece and battery cell

Abstract

The utility model discloses a pole piece and a battery cell, a composite current collector in the pole piece comprises a first area and a second area, the two side surfaces of the first area are respectively provided with an active layer, and the second area comprises a plurality of soft tabs which are sequentially arranged along a first direction; the pole piece further comprises a first conductive adhesive, and the first conductive adhesive comprises a first adhesive body part which is located in the edge area of the outer surface of the first metal layer in at least part of the soft tabs; the second colloid part is positioned in the edge area of the outer surface of the second metal layer in at least part of the soft tabs; and the third colloid part is connected with the first colloid part and the second colloid part. According to the pole piece, conduction of the upper metal layer and the lower metal layer of the composite current collector is achieved by arranging the conductive adhesive on the surfaces of the upper side and the lower side of the soft tab, the process is simple, the cost is low, welding is not needed, and the problems that the welding process is complex, the cost is high, a base material is damaged, the welding yield is low, and the tensile strength of the welding position is low can be solved.

Description

Technical Field

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

[0002] In order to improve the nail penetration performance and impact resistance of the battery cell, technicians in the lithium battery industry began to try to convert the current collector from metal foil (such as copper foil, aluminum foil) to a composite current collector, which includes an insulating support layer and metal layers on the upper and lower sides of the support layer. In order to ensure that the metal layers on both sides of the support layer are conductive to each other, conductive layers are usually welded on the metal layers on both sides of the support layer, and then the excess parts are cut off by die cutting to form multiple soft pole ears of the same size. However, the following problems exist in this process:

[0003] The process of welding the conductive layer to the metal layers on the upper and lower sides of the support layer is complicated and the cost is high;

[0004] Due to the increase in the number of soft tab layers, a high-power welding machine is required for the final transfer welding, and the welding yield is low;

[0005] The tensile strength of the weld is low.

[0006] Therefore, when conducting the metal layers on the upper and lower sides of the support layer, how to avoid complex welding process, high cost, low welding yield and low tensile strength at the weld is a technical problem that needs to be urgently solved by technical personnel in this field. Utility Model Content

[0007] In view of this, the purpose of the utility model is to provide a pole piece and a battery cell, which realizes the conduction of the upper and lower metal layers of the composite current collector by arranging conductive glue on the upper and lower surfaces of the soft pole ear. The process is simple, the cost is low, and no welding is required. It can avoid the problems of complicated welding process, high cost, damage to the substrate, low welding yield, and low tensile strength at the weld.

[0008] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0009] A pole piece, comprising a composite current collector and an active layer, wherein the composite current collector comprises a first metal layer, a support layer, and a second metal layer which are stacked, the composite current collector comprises a first region and a second region, both side surfaces of the first region are respectively provided with the active layer, and the second region comprises a plurality of soft pole ears arranged in sequence along a first direction;

[0010] The pole piece further includes a first conductive adhesive, and the first conductive adhesive includes:

[0011] A first colloid portion is located at an edge region of an outer surface of the first metal layer in at least a portion of the soft electrode tab;

[0012] A second colloid portion is located at an edge region of an outer surface of the second metal layer in at least a portion of the soft electrode tab;

[0013] The third colloid part connects the first colloid part and the second colloid part.

[0014] Optionally, in the above-mentioned pole piece, at least one of the soft pole tabs provided with the first conductive glue comprises a plurality of side edges connected in sequence, and at least a portion of the side edges is provided with the third colloid portion.

[0015] Optionally, in the above-mentioned pole piece, the side edges of the soft pole ear include a first side edge, a second side edge and a third side edge, wherein:

[0016] The first side is parallel to the first direction and is located at one end of the soft electrode ear away from the first region; the second side and the third side are located on both sides of the soft electrode ear, one end of which is connected to the first side and the other end of which is connected to the composite current collector located in the first region;

[0017] The third colloid portion is located on the first side and extends along the extension direction of the first side; and / or, the third colloid portion is located on the second side and extends along the extension direction of the second side; and / or, the third colloid portion is located on the third side and extends along the extension direction of the third side.

[0018] Optionally, in the above-mentioned pole piece, the composite current collector further includes a third region, and the third region is located outside the first region side edge close to the second region of the first region; the third region is provided with a second conductive glue.

[0019] Optionally, in the above-mentioned pole piece, the second conductive glue comprises:

[0020] a fourth colloid portion, located on an outer surface of the first metal layer in the third region;

[0021] a fifth colloid portion, located on an outer surface of the second metal layer in the third region;

[0022] The sixth colloid part connects the fourth colloid part and the fifth colloid part.

[0023] Optionally, in the above-mentioned pole piece, the second conductive adhesive is connected to the first conductive adhesive.

[0024] Optionally, in the above-mentioned pole piece, the width dimension b1 of the first conductive glue is in the range of 0.01 mm≤b1≤2 mm;

[0025] and / or, the thickness dimension h1 of the first colloid part is in the range of h3≤100 μm;

[0026] and / or, the thickness dimension h2 of the second colloid portion is in the range of h4≤100 μm;

[0027] And / or, the width dimension b2 of the second conductive adhesive is in the range of 0.01 mm ≤ b1 ≤ 2 mm;

[0028] and / or, the thickness dimension h3 of the fourth colloid part is in the range of h3≤100 μm;

[0029] And / or, the thickness dimension h4 of the fifth colloid part is in the range of h4≤100 μm.

[0030] A battery cell comprises the pole piece mentioned above.

[0031] Optionally, in the above battery cell, in the third direction, a plurality of the soft electrode tabs are stacked and arranged, and connected by the first conductive adhesive.

[0032] Optionally, the above-mentioned battery cell further includes a hard pole tab, and the hard pole tab is connected to the soft pole tab through the first conductive glue.

[0033] Optionally, in the above battery cell, the electrode piece further includes a third metal layer located on two opposite sides of the second region, and the third metal layer is connected to the soft electrode ear through a first conductive adhesive.

[0034] Optionally, in the above battery core, the hard electrode tab and the third metal layer are connected via a first conductive adhesive.

[0035] It can be seen from the above technical scheme that in the battery cell and its pole piece provided by the utility model, by setting the first conductive adhesive on the upper and lower surfaces and sides of the soft pole ear, the metal layers on the upper and lower sides of the composite current collector (i.e., the first metal layer and the second metal layer) can be connected, and the process is simple and the cost is low. Moreover, in the pole piece, by replacing welding with the first conductive adhesive, the substrate damage caused by welding of the composite current collector can be effectively avoided, as well as the problems of complex welding process, high cost, low welding yield, low tensile strength at the welding point, etc., which can greatly improve the tensile strength of the soft pole ear. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 The diagram is a schematic diagram of a pole piece structure provided with an active layer and a plurality of soft pole ears.

[0038] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure decomposition of the electrode at the position of the dot-dash line L1 (the composite current collector and the active layer in the electrode are separated).

[0039] Figure 3 A schematic diagram of the structure when the first conductive glue is arranged in the edge area (entirely) of the soft electrode ear provided in an embodiment of the utility model.

[0040] Figure 4 Schematic diagrams of various exemplary structures when the first conductive adhesive is provided in the edge area (part) of the soft electrode ear according to the embodiments of the present invention.

[0041] Figure 5 for Figure 3 The cross-sectional structure diagram of the position of the dotted line L2 in FIG. Figure 4 Schematic diagram of the cross-sectional structure at the position of the dot-dash line L3.

[0042] Figure 6 A schematic diagram of a pole piece structure in which conductive glue is arranged at the edge area of ​​the pole piece provided in an embodiment of the utility model.

[0043] Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure at the position of the dotted line L4.

[0044] Figure 8 A schematic structural diagram of a soft tab combination external module provided in an embodiment of the utility model.

[0045] Fig. 9 A schematic diagram of the connection structure of a hard pole tab and a soft pole tab combined external module provided in an embodiment of the utility model.

[0046] Fig.10 A schematic diagram of the connection structure of the conductive foil and the soft electrode ear provided in an embodiment of the utility model.

[0047] in:

[0048] 1-composite current collector, 2-active layer, 3-soft pole ear, 5-hard pole ear, 6-third metal layer,

[0049] 11-first metal layer, 12-support layer, 13-second metal layer,

[0050] 41-first conductive adhesive, 42-second conductive adhesive,

[0051] 411-first colloid part, 412-second colloid part, 413-third colloid part,

[0052] 421 - the fourth colloid portion, 422 - the fifth colloid portion, 423 - the sixth colloid portion. DETAILED DESCRIPTION

[0053] The utility model discloses a pole piece and a battery cell, which realize conduction of the upper and lower metal layers of a composite current collector by arranging conductive glue on the upper and lower surfaces of a soft pole ear. The process is simple, the cost is low, and no welding is required, which can avoid the problems of complex welding process, high cost, damage to the substrate, low welding yield, low tensile strength at the weld, etc.

[0054] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0055] See also Figure 1 and Figure 2 The pole piece provided by the embodiment of the utility model includes a composite current collector 1 and an active layer 2. The composite current collector 1 includes a first metal layer 11, a support layer 12, and a second metal layer 13. The first metal layer 11, the support layer 12, and the second metal layer 13 are stacked in the thickness direction of the pole piece. Moreover, the composite current collector 1 includes a first area A1 and a second area A2: the first area A1 is the main part of the current collector, and the active layer 2 is respectively arranged on both sides thereof; the second area A2 is located on the side of the current collector, and includes a plurality of soft pole ears 3 arranged in sequence along the first direction (i.e., the length direction of the pole piece).

[0056] For further information, see Figures 3 to 5, the electrode piece is also provided with a first conductive glue 41, and the first conductive glue 41 is divided into a first colloid part 411, a second colloid part 412, and a third colloid part 413 according to its different positions on the soft pole ear, wherein the first colloid part 411 covers at least a portion of the edge area of ​​the outer surface of the first metal layer 11 in the soft pole ear 3, the second colloid part 412 covers at least a portion of the edge area of ​​the outer surface of the second metal layer 13 in the soft pole ear 3, and the third colloid part 413 connects the first colloid part 411 and the second colloid part 412. It can be seen that the outer side surfaces of the upper and lower metal layers in the soft pole ear 3 are respectively provided with the first conductive glue 41, at least in the area close to the side, and the upper and lower metal layers in the soft pole ear 3 are conductively connected through the first conductive glue 41. It should be noted here that the "edge area" mentioned in this article refers to a partial area located on the side of the part, which is adjacent to the side of the part and extends with the side of the part. For details, please refer to Figure 3 The gray area covered by the first colloid portion 411 in FIG.

[0057] It can be seen that the pole piece provided by the embodiment of the utility model can realize the conduction of the metal layers (i.e., the first metal layer 11 and the second metal layer 13) on the upper and lower surfaces and sides of the soft pole ear 3 by setting the first conductive glue 41, and the process is simple and the cost is low. Moreover, in the pole piece, the first conductive glue 41 is used instead of welding to effectively avoid the damage to the substrate caused by the composite current collector 1 during welding, as well as the problems of complex welding process, high cost, low welding yield, and low tensile strength at the welding point, which can greatly improve the tensile strength of the soft pole ear 3.

[0058] In a specific implementation, the second area A2 is provided on at least one side of the composite current collector 1 by die-cutting, that is, one or more soft pole ears 3 are provided on at least one side of the composite current collector 1, each soft pole ear 3 is not coated with the active layer 2, and a first conductive glue 41 is provided in at least part of the edge area, so as to realize the function of charging and discharging the pole piece. Among them, part or all (that is, at least one) of the multiple soft pole ears 3 are provided with the first conductive glue 41. Moreover, at least one soft pole ear 3 provided with the first conductive glue 41 includes a plurality of sides connected in sequence, and each side is respectively provided with a third colloid part 413, such as Figure 3 and Figure 5 Or, at least one soft electrode ear 3 provided with a first conductive glue 41 includes a plurality of side edges connected in sequence, wherein at least a portion of the side edges is provided with a third colloid portion 413, such as Figure 4 and Figure 5As shown in . In short, in a specific implementation, as long as part of the soft pole tabs 3 in the pole piece are connected through the first colloid part 411, the second colloid part 412, and the third colloid part 413 in the first conductive glue 41, the conduction of the upper and lower metal layers of the composite current collector 1 in the pole piece can be guaranteed. Therefore, in a specific embodiment, the plurality of soft pole tabs 3 of the pole piece can be respectively connected through the first colloid part 411, the second colloid part 412, and the third colloid part 413 in the first conductive glue 41; or, in some embodiments, at least one soft pole tab 3 in each pole piece can be connected through the first colloid part 411, the second colloid part 412, and the third colloid part 413 in the first conductive glue 41, and the remaining soft pole tabs 3 may not be provided with the third colloid part 413 or the first conductive glue 41.

[0059] See also Figure 4 In some embodiments, the side of the soft pole ear 3 includes a first side, a second side and a third side, wherein: the first side is parallel to the first direction and is located at one end of the soft pole ear 3 away from the first area A1; the second side and the third side are respectively located on both sides of the soft pole ear 3, one end of the second side is connected to the first side, and the other end is connected to the composite current collector 1 located in the first area A1, and one end of the third side is connected to the first side, and the other end is connected to the composite current collector 1 located in the first area A1. In addition, the third colloid portion 413 is located on the first side and extends along the extension direction of the first side. At this time, the first conductive adhesive 41 is located on the first side as a whole and extends along the extension direction of the first side, that is, the first colloid portion 411, the second colloid portion 412, and the third colloid portion 413 in the first conductive adhesive 41 are all located on the first side and extend along the extension direction of the first side; and / or, the third colloid portion 413 is located on the second side and extends along the extension direction of the second side. At this time, the first conductive adhesive 41 is located on the second side as a whole and extends along the extension direction of the second side. Extension, that is, the first colloid part 411, the second colloid part 412, and the third colloid part 413 in the first conductive glue 41 are all located on the second side and extend along the extension direction of the second side; and / or, the third colloid part 413 is located on the third side and extends along the extension direction of the third side. At this time, the first conductive glue 41 is located on the third side as a whole and extends along the extension direction of the third side, that is, the first colloid part 411, the second colloid part 412, and the third colloid part 413 in the first conductive glue 41 are all located on the third side and extend along the extension direction of the third side.

[0060] In some embodiments, the first conductive adhesive 41 may be composed of a binder and a conductive filler, wherein the binder component is polyolefin, and the conductive filler is any one or more of Ag, Ni, Cu, Au, and Al. The resistivity of the first conductive adhesive 41 is ρ≤100Mω / cm 2 .

[0061] See also Figure 5In some embodiments, in the third direction (i.e., the thickness direction of the electrode, which is perpendicular to the plane formed by the first direction and the second direction), the thickness h1 of each layer of the first colloid part 411 is in the range of h1≤100μm, and the thickness h2 of each layer of the second colloid part 412 is in the range of h2≤100μm. Figures 3 to 5 As shown, the first conductive adhesive 41 is perpendicular to the side of the soft electrode ear (see Figure 3 The extension direction of the dot-dash line L2, and Figure 4 The width dimension b1 in the extension direction of the straight line L3 in the electrode is in the range of 0.01 mm ≤ b1 ≤ 2 mm. In addition, in any electrode piece, if the thickness of the active layer 2 is H2, the thickness of the first conductive glue 41 on the single soft electrode tab 3 is H4', and the thickness of the single soft electrode tab 3 is H3, then H2>H4'>H3.

[0062] For further information, see Figure 6 In some embodiments, the composite current collector 1 further includes a third region A3, which is located outside the first region side L5 of the first region A1 close to the second region A2, and is spaced apart from the roots of the plurality of soft pole ears 3 along the first direction, and the third region A3 is provided with a second conductive glue 42. Specifically, the second conductive glue 42 includes a fourth colloid portion 421, a fifth colloid portion 422, and a sixth colloid portion 423, wherein: the fourth colloid portion 421 is located outside the root of the soft pole ear 3, covering the outer surface of the first metal layer 11 in the third region A3; the fifth colloid portion 422 is located outside the root of the soft pole ear 3, covering the outer surface of the second metal layer 13 in the third region A3; the sixth colloid portion 423 connects the fourth colloid portion 421 and the fifth colloid portion 422. For details, please refer to Figure 6 and Figure 7 , Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure at the position of the dot-dash line L4 in FIG. It can be seen that the outer side surfaces of the metal layers on the upper and lower sides of the third area A3 located in the main edge area of ​​the composite current collector 1 are both provided with a second conductive adhesive 42, and the conductive connection is achieved through the second conductive adhesive 42. In a preferred embodiment, the second conductive adhesive 42 is connected to the first conductive adhesive 41.

[0063] In a specific implementation, before the electrode is die-cut, a portion of the area near the long side of the electrode and not coated with the active layer 2 can be reserved. For details, see Figure 6The area between the side L5 of the first area and the line L6 connecting the root of the soft pole ear; at the same time, die-cutting is performed in the area of ​​the uncoated active layer 2 between L6 and the long side of the pole piece to obtain a plurality of soft pole ears 3, and at this time, the plurality of soft pole ears 3 constitute the second area A2 described above. Then, conductive glue is provided on the upper and lower surfaces and the outer sides of at least part of the third area A3 and at least part of the second area A2 of the uncoated active layer 2. Among them, the second conductive glue 42 covers the third area A3 and its sides, and the first conductive glue 41 covers the upper and lower surface edge areas and the sides of the second area A2. It is preferred that the first conductive glue 41 located in the second area A2 and the second conductive glue 42 located in the third area A3 are connected in sequence. It can be seen that in the pole piece, not only is the first conductive glue 41 arranged at the edge area and outside the side of the soft pole ear 3, but also a third area A3 not coated with the active layer 2 is arranged at the edge area of ​​the pole piece body, and a second conductive glue 42 is arranged in the third area A3. The second conductive glue 42 and the first conductive glue 41 are beneficial to increase the conduction area of ​​the metal layers on the upper and lower sides of the composite current collector 1 (i.e., the first metal layer 11 and the second metal layer 13), improve the conductive reliability, reduce the internal resistance of the pole piece, and reduce the battery impedance.

[0064] In some embodiments, the second conductive adhesive 42 may be composed of a binder and a conductive filler, wherein the binder component is polyolefin, and the conductive filler is any one or more of Ag, Ni, Cu, Au, and Al. The resistivity of the second conductive adhesive 42 is ρ≤100Mω / cm 2 .

[0065] Also, see Figure 7 In some embodiments, in the third direction (i.e., the thickness direction of the electrode, which is perpendicular to the plane formed by the first direction and the second direction), the thickness h3 of each layer of the fourth colloid part 421 is in the range of h3≤100μm, and the thickness h4 of each layer of the fifth colloid part 422 is in the range of h4≤100μm. Figure 6 to Figure 7 As shown, the second conductive adhesive 42 is perpendicular to the side of the soft electrode ear (see Figure 6 The width dimension b2 in the extension direction of the dotted line L4) is in the range of 0.01mm≤b2≤2mm. In addition, in any electrode piece, if the thickness of the active layer 2 is H2, the thickness of the second conductive glue 42 is H4", and the thickness of a single soft electrode ear 3 is H3, then H2>H4”>H3.

[0066] In addition, the embodiment of the utility model further provides a battery cell, which includes the pole piece described above. Figure 8, in the third direction, the multiple soft pole ears 3 in the battery cell are stacked and connected by the first conductive adhesive 41 to form a soft pole ear combination external module. The "multiple soft pole ears 3" mentioned in this paragraph can be soft pole ears on multiple different pole pieces in a laminated battery, that is, when multiple pole pieces are stacked, their soft pole ears are aligned up and down respectively to form a structure in which multiple soft pole ears 3 are stacked; or, the "multiple soft pole ears 3" mentioned in this paragraph can also be multiple soft pole ears in the same pole piece in a rolled core battery that are stacked and arranged in the same projection area. In other words, in some embodiments, the battery cell is a winding structure, and the multiple soft pole ears 3 in the soft pole ear combination external module are located on the same pole piece; or, in some embodiments, the battery cell is a laminated structure, and the multiple soft pole ears 3 in the soft pole ear combination external module are located on multiple pole pieces of the same polarity and different positions. It can be seen that in a specific embodiment, when the electrode sheet provided with the first conductive glue 41 and the diaphragm are wound or stacked, the first conductive glue 41 provided on the soft electrode ear 3 can realize the fixation and electrical connection of the multi-layer soft electrode ear 3, and no welding is required, and no other material layers need to be added. The number of material layers at the connection of the multi-layer soft electrode ear 3 can be effectively reduced, and the battery yield can be improved. Moreover, the process is simple and the cost is low.

[0067] like Fig. 9 As shown, after the electrode sheet winding or lamination process is completed, the hard electrode ear 5 (or called the main electrode ear) can be fixed and electrically connected through the soft electrode ear combination external connection module composed of the first conductive glue 41 and the multi-layer soft electrode ear 3 to realize the function of connecting the battery cell with the external charging and discharging device. Among them, in the third direction, the thickness of the single-layer hard electrode ear> the thickness of the single-layer conductive glue between adjacent soft electrode ears> the thickness of the single-layer soft electrode ear.

[0068] Or, if Fig.10 As shown, after the electrode glue coating process is completed, the third metal layer 6 (such as conductive foil) is connected to the upper and lower sides of the soft pole ear 3 through the first conductive glue 41. Specifically, one layer of the third metal layer 6 is connected to one side of the soft pole ear 3 through the first colloid part 411, and extends outwardly relative to the soft pole ear 3 by a certain length; another layer of the third metal layer 6 is connected to the other side of the soft pole ear 3 through the second colloid part 412, and extends outwardly relative to the soft pole ear 3 by a certain length, so as to realize the function of connecting the battery cell with the external charging and discharging device. Furthermore, it also includes a hard pole ear 5, and the hard pole ear 5 and the third metal layer 6 are connected by the first conductive glue 41.

[0069] In specific implementation, the first conductive adhesive 41 and the second conductive adhesive 42 can be applied by a precision adhesive dispensing valve to ensure that the thickness of each layer of conductive adhesive is substantially equal. However, this is not limited to this. In other embodiments, the first conductive adhesive 41 and the second conductive adhesive 42 can also be provided by other methods, and the present invention does not specifically limit this.

[0070] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0071] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0072] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pole piece, comprising a composite current collector (1) and an active layer (2), wherein the composite current collector (1) comprises a first metal layer (11), a support layer (12) and a second metal layer (13) which are stacked, wherein the composite current collector (1) comprises a first region (A1) and a second region (A2), wherein the active layer (2) is disposed on both side surfaces of the first region (A1), and the second region (A2) comprises a plurality of soft pole tabs (3) arranged in sequence along a first direction; It is characterized in that It also includes a first conductive adhesive (41), wherein the first conductive adhesive (41) includes: A first colloid portion (411) is located in an edge region of an outer surface of the first metal layer (11) in at least a portion of the soft electrode tab (3); A second colloid portion (412) is located in an edge region of an outer surface of the second metal layer (13) in at least a portion of the soft electrode tab (3); The third colloid part (413) connects the first colloid part (411) and the second colloid part (412).

2. The pole piece according to claim 1, characterized in that: At least one of the soft pole tabs (3) provided with the first conductive glue (41) comprises a plurality of side edges connected in sequence, and at least a portion of the area of ​​at least some of the side edges is provided with the third glue portion (413).

3. The pole piece according to claim 2, characterized in that: The side edges of the soft electrode tab (3) include a first side edge, a second side edge and a third side edge, wherein: The first side edge is parallel to the first direction and is located at an end of the soft electrode ear (3) away from the first area (A1); The second side and the third side are respectively located on both sides of the soft electrode ear (3), one end of which is connected to the first side and the other end of which is connected to the composite current collector (1) located in the first area (A1); The third colloid portion (413) is located at the first side and extends along the extension direction of the first side; and / or, The third colloid portion (413) is located at the second side and extends along the extension direction of the second side; and / or, The third colloid portion (413) is located on the third side and extends along the extension direction of the third side.

4. The pole piece according to claim 1, characterized in that: The composite current collector (1) further comprises a third region (A3), wherein the third region (A3) is located outside a first region side edge (L5) of the first region (A1) close to the second region (A2); The third area (A3) is provided with a second conductive adhesive (42).

5. The pole piece according to claim 4, characterized in that: The second conductive adhesive (42) comprises: a fourth colloid portion (421) located on the outer surface of the first metal layer (11) in the third area (A3); a fifth colloid portion (422) located on the outer surface of the second metal layer (13) in the third area (A3); The sixth colloid part (423) connects the fourth colloid part (421) and the fifth colloid part (422).

6. The pole piece according to claim 5, characterized in that: The second conductive adhesive (42) is connected to the first conductive adhesive (41).

7. The pole piece according to claim 5 or 6, characterized in that: The width dimension b1 of the first conductive adhesive (41) is in the range of 0.01 mm ≤ b1 ≤ 2 mm; and / or, the thickness dimension h1 of the first colloid part (411) is in the range of h3≤100 μm; and / or, the thickness dimension h2 of the second colloid part (412) is in the range of h4≤100 μm; And / or, the width dimension b2 of the second conductive adhesive (42) is in the range of 0.01 mm ≤ b1 ≤ 2 mm; And / or, the thickness dimension h3 of the fourth colloid part (421) is in the range of h3≤100 μm; And / or, the thickness dimension h4 of the fifth colloid part (422) is in the range of h4≤100 μm.

8. A battery cell, characterized in that: Comprising a pole piece as claimed in any one of claims 1 to 7.

9. The battery cell according to claim 8, characterized in that: In the third direction, a plurality of the soft electrode tabs (3) are stacked and connected via the first conductive adhesive (41).

10. The battery cell according to claim 9, characterized in that: Also includes: A hard pole tab (5), wherein the hard pole tab (5) is connected to the soft pole tab (3) via the first conductive adhesive (41).

11. The battery cell according to claim 8, characterized in that: The pole piece further comprises a third metal layer (6) located on two opposite sides of the second area (A2), and the third metal layer (6) is connected to the soft pole ear (3) via a first conductive adhesive (41).

12. The battery cell according to claim 11, characterized in that: Also includes: A hard pole tab (5), wherein the hard pole tab (5) and the third metal layer (6) are connected via a first conductive adhesive (41).

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