CN216354653U - Battery core and battery - Google Patents

Abstract

The application provides an electric core and a battery, wherein the electric core comprises an electric core body, a switching piece and a pole lug group, the pole lug group comprises a plurality of pole lugs which are arranged in a stacking mode along the thickness direction of the electric core body, the switching piece is respectively connected with at least part of the pole lugs in the pole lug group, each pole lug comprises an insulating layer, a first conducting layer and a second conducting layer, and the first conducting layer and the second conducting layer respectively cover two opposite surfaces of the insulating layer; the battery cell body comprises a first surface and a second surface which are opposite to each other along the thickness direction; in the pole lug group, the pole lug closest to the first surface in the pole lugs is an outer pole lug, and the extension length of at least one of the other pole lugs except the outer pole lug is greater than that of the outer pole lug. The conductive layer on the inner side can be exposed out of the end face, facing the first face, of the pole lug group, so that the adaptor can be electrically connected with more conductive layers. Therefore, the battery core and the battery provided by the application can improve the conduction ratio of the conducting layers in the plurality of tabs and reduce the internal resistance of the battery.

Description

Battery core and battery

Technical Field

The application relates to the technical field of batteries, in particular to an electric core and a battery.

Background

The lithium ion battery has the advantages of large capacity, small volume, light weight, environmental protection and the like, and is widely applied to industries such as digital electronic products, electric automobiles and the like.

In the related art, the battery cell includes a battery cell body and a plurality of tabs, and the tabs may be formed of a metal material. In order to reduce the weight of the tab and increase the energy density of the battery, a polymer with lower density can be used to replace part of the metal in the tab, for example, the tab with a sandwich structure of metal layer-polymer layer-metal layer.

However, the polymer layer in the tab is made of an insulating material, and the metal layers on both sides of the tab are isolated by the polymer layer and cannot be conducted, so that the conduction ratio of the metal layers on the tabs is low, and the internal resistance of the battery is high.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing problems, embodiments of the present application provide a battery cell and a battery, which can increase the conduction ratio of metal layers of a plurality of tabs and reduce the internal resistance of the battery.

In order to achieve the above object, the embodiments of the present application provide the following technical solutions:

a first aspect of an embodiment of the present application provides an electrical core, including an electrical core body, an adaptor and a tab group, where the tab group includes a plurality of tabs stacked in a thickness direction of the electrical core body, the adaptor is connected to at least some tabs in the tab group, each tab includes an insulating layer, a first conductive layer and a second conductive layer, and the first conductive layer and the second conductive layer cover two opposite surfaces of the insulating layer respectively;

the battery cell body comprises a first surface and a second surface which are opposite to each other along the thickness direction;

in the pole lug group, the pole lug closest to the first surface in the pole lugs is an outer pole lug, and the extension length of at least one of the other pole lugs except the outer pole lug is greater than that of the outer pole lug.

The electric core that this embodiment provided, electric core include electric core body, adaptor and utmost point ear group, and utmost point ear group includes a plurality of utmost point ears that range upon range of setting in the thickness direction along electric core body, and the adaptor is connected with at least part utmost point ear in the utmost point ear group respectively. The tab comprises an insulating layer, a first conducting layer and a second conducting layer, wherein the first conducting layer and the second conducting layer cover two opposite surfaces of the insulating layer respectively, the insulating layer can adopt a light polymer layer, and the first conducting layer and the second conducting layer can adopt metal layers, so that the weight of the tab is reduced, and the energy density of a battery is improved. The battery cell body comprises a first surface and a second surface which are opposite to each other in the thickness direction. In the pole lug group, the pole lug closest to the first surface in the plurality of pole lugs is an outer pole lug, and the extension length of at least one of the other pole lugs except the outer pole lug in the plurality of pole lugs is greater than that of the outer pole lug. Like this, can expose inboard metal level at the terminal surface of the first face of orientation of utmost point ear group for the adaptor can realize electric connection with more metal levels, with the proportion of the metal level that is switched on in improving utmost point ear group, thereby reduce the internal resistance of electricity core.

In one possible implementation manner, in the tab group, along the direction from the first surface to the second surface, the extension lengths of the tabs sequentially increase and then decrease.

In one possible implementation manner, in the pole lug group, the extension lengths of the plurality of pole lugs are sequentially increased along the direction from the first surface to the second surface.

In one possible implementation, the thickness of the insulating layer is not more than 20 μm;

and/or the thickness of the first conductive layer is not more than 5 μm;

and/or the thickness of the second conductive layer is not more than 5 μm;

and/or the extension length of each tab ranges from 1mm to 30 mm;

and/or the length of each tab along the direction perpendicular to the extension length ranges from 2mm to 60 mm;

and/or in the pole lug group, along the thickness direction of the battery cell body, the difference value of the extension length of each two adjacent pole lugs is the same;

and/or in the pole lug group, along the thickness direction of the battery cell body, the difference range of the extension lengths of two adjacent pole lugs is 0.5mm-10 mm;

and/or, in the pole ear group, the number of pole ears ranges from 2 to 50;

and/or, in the pole ear group, the number of the pole ears is odd.

In one possible implementation manner, the adaptor includes a clamping portion, and the clamping portion includes a first clamping portion and a second clamping portion that are connected and oppositely disposed;

the first clamping portion is connected with the end face, facing the first face, of the polar lug group, and the second clamping portion is connected with the end face, facing the second face, of the polar lug group.

In one possible implementation manner, the first conductive layer is arranged on a surface of the tab facing the first surface, the second conductive layer is arranged on a surface of the tab facing the second surface, the first clamping portion is connected with at least part of the first conductive layer in the tab group, and the second clamping portion is connected with at least part of the second conductive layer in the tab group;

and/or the clamping part is welded with the polar lug group to form a welding stamp, the welding stamp penetrates through the polar lug group along the thickness direction of the polar lug group, one end, close to the first surface, of the welding stamp is connected with the first clamping part, and one end, close to the second surface, of the welding stamp is connected with the second clamping part.

In a possible implementation manner, the adaptor further includes an extension portion, and the extension portion is connected with one end of the clamping portion, which is away from the battery cell body;

wherein the content of the first and second substances,

the thickness of the clamping part is not less than that of the extension part;

and/or the extension has a thickness in the range of 0.01mm to 1 mm;

and/or, along the direction of the extension length, the length range of the adapter is 5mm-100 mm;

and/or the length of the adapter in a direction perpendicular to the extension length ranges from 1mm to 80 mm.

In one possible implementation manner, the battery cell body comprises a first pole piece and a second pole piece which are mutually overlapped and have opposite polarities, and a diaphragm is arranged between the adjacent first pole piece and the second pole piece; the polar lug group comprises a first polar lug group and a second polar lug group, the first pole piece is electrically connected with the first polar lug group, and the second pole piece is electrically connected with the second polar lug group;

the first pole lug group comprises a plurality of first pole lugs, and the first pole lugs are stacked in the thickness direction of the battery cell body; along the direction from the first surface to the second surface, the extension lengths of the first tabs are sequentially increased and then decreased;

and/or the second pole lug group comprises a plurality of second pole lugs, and the second pole lugs are stacked along the thickness direction of the battery cell body; along the direction of first face to second face, the extending length of a plurality of second utmost point ears increases earlier in proper order then reduces.

In one possible implementation manner, the first pole piece and the second pole piece are both one, and the first pole piece, the diaphragm and the second pole piece which are sequentially stacked are wound around a winding center to form a winding structure; a plurality of first tabs are arranged on the first pole piece; and/or a plurality of second tabs are arranged on the second pole piece;

or the first pole piece and the second pole piece are multiple, the multiple first pole pieces and the multiple second pole pieces are sequentially staggered and stacked along the same direction, and a diaphragm is arranged between every two adjacent first pole pieces and second pole pieces; each first pole piece is provided with a first pole lug, and each second pole piece is provided with a second pole lug.

A second aspect of the embodiments of the present application provides a battery, including the battery cell in the first aspect.

The battery that this embodiment provided, battery include electric core, and electric core includes electric core body, adaptor and utmost point ear group, and utmost point ear group includes a plurality of utmost point ears that range upon range of setting along the thickness direction of electric core body, and the adaptor is connected with at least some utmost point ears in the utmost point ear group respectively. The tab comprises an insulating layer, a first conducting layer and a second conducting layer, wherein the first conducting layer and the second conducting layer cover two opposite surfaces of the insulating layer respectively, the insulating layer can adopt a light polymer layer, and the first conducting layer and the second conducting layer can adopt metal layers, so that the weight of the tab is reduced, and the energy density of a battery is improved. The battery cell body comprises a first surface and a second surface which are opposite to each other in the thickness direction. In the pole lug group, the pole lug closest to the first surface in the plurality of pole lugs is an outer pole lug, and the extension length of at least one of the other pole lugs except the outer pole lug in the plurality of pole lugs is greater than that of the outer pole lug. Like this, can expose inboard metal level at the terminal surface of the first face of orientation of utmost point ear group for the adaptor can realize electric connection with more metal levels, with the proportion of the metal level that is switched on in improving utmost point ear group, thereby reduce the internal resistance of electricity core.

The construction of the present application and other objects and advantages thereof will be more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of an adapter provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a pole piece provided in an embodiment of the present application;

fig. 4 is a sectional view taken along the line a-a in fig. 3.

Description of reference numerals:

100: an electric core;

200: a cell body;

210: a first side;

220: a second face;

230: pole pieces;

231: a current collector;

232: an active material layer;

300: a pole ear group;

310: a tab;

311: a first conductive layer;

312: a second conductive layer;

313: an insulating layer;

320: an outer tab;

400: an adapter;

411: a first clamping section;

412: a second clamping section;

420: an extension portion.

Detailed Description

In the related art, the battery core includes a battery core body, and two electrode ear groups are arranged on the battery core body, for example, the two electrode ear groups may be a positive electrode ear group and a negative electrode ear group. In same utmost point ear group, utmost point ear group includes a plurality of utmost point ears of following the range upon range of setting of electricity core body thickness direction. The pole lug comprises a light insulating layer and metal layers covering two opposite surfaces of the insulating layer, and the insulating layer is adopted to replace part of the metal layers, so that the overall quality of the pole lug can be reduced, and the energy density of the battery is improved.

However, the length of the tab is an extended length in the width direction of the pole piece, and the extended lengths of the tabs are all equal. Therefore, the insulating layer of the tab located at the outermost side of the tab group blocks the metal layer located at the inner side of the insulating layer, so that the metal layer located at the inner side of the insulating layer cannot be electrically connected with an external circuit structure, the proportion of the conducted metal layer in each tab is low, and the internal resistance of the battery is increased.

Based on foretell problem, this embodiment provides an electricity core and battery, and electricity core includes electric core body, adaptor and utmost point ear group, and utmost point ear group includes a plurality of utmost point ears that set up along the range upon range of thickness direction of electric core body, and the adaptor is connected with at least part utmost point ear in the utmost point ear group respectively. The tab comprises an insulating layer, a first conducting layer and a second conducting layer, wherein the first conducting layer and the second conducting layer cover two opposite surfaces of the insulating layer respectively, the insulating layer can adopt a light polymer layer, and the first conducting layer and the second conducting layer can adopt metal layers, so that the weight of the tab is reduced, and the energy density of a battery is improved. The battery cell body comprises a first surface and a second surface which are opposite to each other in the thickness direction. In the pole lug group, the pole lug closest to the first surface in the plurality of pole lugs is an outer pole lug, and the extension length of at least one of the other pole lugs except the outer pole lug in the plurality of pole lugs is greater than that of the outer pole lug. Like this, can expose inboard metal level at the terminal surface of the first face of orientation of utmost point ear group for the adaptor can realize electric connection with more metal levels, with the proportion of the metal level that is switched on in improving utmost point ear group, thereby reduce the internal resistance of electricity core.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the present application provides a battery, as shown in fig. 1, the battery includes a battery cell 100, where the battery cell 100 refers to an electrochemical cell that is installed inside the battery and includes positive and negative electrode plates. The battery cell 100 is not generally used directly, and a battery for charge/discharge may be formed by mounting the battery cell 100 inside a battery case. Since the battery cell 100 is a power storage portion in the battery, the quality of the battery cell 100 directly determines the quality of the battery.

The following provides a detailed description of the battery cell 100 provided in the embodiment of the present application.

As shown in fig. 2 and fig. 3, the battery cell 100 includes a cell body 200, where the cell body 200 includes at least two pole pieces 230 that are stacked on each other and have opposite polarities, and a diaphragm is disposed between two adjacent pole pieces 230.

In the embodiment of the present application, the X direction shown in fig. 3 is the length direction of the pole piece 230, and the Y direction shown in fig. 3 is the width direction of the pole piece 230. The extending direction of the extending length of the tab 310 coincides with the width direction of the pole piece 230, that is, the length of the tab 310 in the Y direction is the extending length. It is to be understood that the length direction and the width direction described in the embodiments of the present application are only for convenience of description and are not meant to be limiting in any dimension, for example, the length may be shorter than the width.

As shown in fig. 2, the cell body 200 includes a first surface 210 and a second surface 220, which are oppositely disposed, along the thickness direction of the cell body 200

In this embodiment, as shown in fig. 4, the pole piece 230 includes a current collector 231, and a tab 310 is connected to the current collector 231.

Specifically, the tab 310 includes an insulating layer 313, a first conductive layer 311, and a second conductive layer 312, and the first conductive layer 311 and the second conductive layer 312 cover opposite surfaces of the insulating layer 313, respectively. The first conductive layer 311 and the second conductive layer 312 may be metal layers, the material of the metal layers may be aluminum, copper, or the like, and the metal layers may be coated or otherwise covered on the surface of the insulating layer 313. The insulating layer 313 may be polyethylene terephthalate (PET), non-woven fabric, or other lightweight insulating material.

The conductive layer of the tab 310 facing the first surface 210 is a first conductive layer 311, and the conductive layer of the tab 310 facing the second surface 220 is a second conductive layer 312.

It is realized that, as shown in fig. 4, the current collector 231 and the tab 310 may have the same material and structure, for example, one end edge of the current collector 231 in the width direction may be subjected to laser die cutting to form a plurality of tabs 310. In this way, the insulating layer 313 of the current collector 231 and the insulating layer 313 of the tab 310, the first conductive layer 311 of the current collector 231 and the first conductive layer 311 of the tab 310, and the second conductive layer 312 of the current collector 231 and the second conductive layer 312 of the tab 310 are integrally formed, so that the connection strength between the current collector 231 and the tab 310 is high.

It is realized that the material and structure of the current collector 231 and the tab 310 may be different.

It is realized that the thickness of the insulating layer 313 is not more than 20 μm. Illustratively, the thickness of the insulating layer 313 may be 1 μm, 3 μm, 5 μm, 7 μm, 10 μm, 13 μm, 15 μm, 17 μm, or 20 μm, so that it may be avoided that the insulating layer 313 is too thick, which may result in occupying a large space inside the battery.

It is realized that the thickness of the first conductive layer 311 is not more than 5 μm. Illustratively, the thickness of the first conductive layer 311 may be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, or 5 μm, so as to avoid that the first conductive layer 311 is too thick, which may occupy a large space inside the battery.

It can be realized that the thickness of the second conductive layer 312 is not more than 5 μm. For example, the thickness of the second conductive layer 312 may be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, or 5 μm, etc., and the principle thereof is similar to that of the first conductive layer 311 and is not described again.

In addition, as shown in fig. 4, the pole piece 230 further includes an active material layer 232, and the active material layer 232 is coated on the surface of the current collector 231, it is understood that the active material layer 232 may be coated on one surface or both surfaces of the current collector 231, or a partial area of one surface of the current collector 231, or a partial area of both surfaces of the current collector 231 according to the manufacturing requirement of the pole piece 230.

In particular, the at least two pole pieces 230 may include a first pole piece and a second pole piece. That is, the cell body 200 may include a first pole piece, a diaphragm and a second pole piece, the polarities of the first pole piece and the second pole piece are opposite, the diaphragm is located between the adjacent first pole piece and the adjacent second pole piece, and the diaphragm is used to electrically insulate the first pole piece and the second pole piece. The first pole piece can be provided with a first pole lug, and the second pole piece can be provided with a second pole lug.

One of the first and second pole pieces may be a negative pole piece, and the other of the first and second pole pieces may be a positive pole piece.

In some examples, the cell body 200 may be a wound cell body. The first pole piece, the diaphragm and the second pole piece which are sequentially stacked are wound around a winding center to form a winding structure.

It can be realized that a plurality of first tabs can be connected to the first pole piece.

It can be realized that a plurality of second tabs can be connected to the second tab.

It can be realized that a first tab is connected to the first pole piece.

It is possible to realize that a second tab is connected to the second tab.

In other examples, the cell body 200 may be a laminated cell body. The first pole pieces are multiple, the second pole pieces are multiple, the multiple first pole pieces and the multiple second pole pieces are sequentially arranged in a staggered and stacked mode along the same direction, and a diaphragm is arranged between every two adjacent first pole pieces and every two adjacent second pole pieces, so that the first pole pieces and the second pole pieces are electrically insulated. Each first pole piece is connected with a first pole lug, and each second pole piece is connected with a second pole lug.

In the embodiment of the present application, as shown in fig. 1, a tab group 300 is disposed on the battery cell body 200, and the tab group 300 is composed of tabs 310. The number of the polar ear groups 300 may be plural, for example, the number of the polar ear groups 300 is two, three or four, etc.

The number of the tabs 310 in the tab group 300 is at least one, that is, the number of the tabs 310 in the tab group 300 may be one or more.

The present embodiment is described with the number of tabs 310 in the tab group 300 being plural.

In this embodiment, the battery cell 100 further includes an adaptor 400, and the number of the adaptor 400 may be multiple, for example, the number of the adaptor 400 is two, three, or four.

The plurality of adapters 400 are connected with the plurality of tab sets 300 in a one-to-one correspondence manner, that is, one of the tab sets 300 is correspondingly connected with one of the adapters 400. The adaptor 400 and the tab set 300 may be connected by ultrasonic welding, laser welding, riveting, resistance welding, etc., and the tab 310 in the tab set 300 is led out to an external circuit structure through the adaptor 400.

The adaptor 400 corresponding to the tab set 300 is connected to at least some of the tabs 310 in the tab set 300, wherein the adaptor 400 can be connected to at least two tabs 310 in the tab set 300, for example, the number of tabs 310 connected by the adaptor 400 is 2, 3, 4 or more.

For example, the material of the interposer 400 may be aluminum, copper, nickel, or the like.

Specifically, as shown in fig. 2, the interposer 400 includes a clamping portion, the clamping portion includes a first clamping portion 411 and a second clamping portion 412 that are connected and disposed opposite to each other, and the tab group 300 is clamped between the first clamping portion 411 and the second clamping portion 412, so that the interposer 400 and the tab group 300 are electrically connected to each other. The first interposed portion 411 is connected to an end surface of the corresponding tab group 300 facing the first surface 210. The second interposed portion 412 is connected to an end surface of the corresponding tab group 300 facing the second surface 220.

The thicknesses of the first and second sandwiching portions 411 and 412 may be the same or different.

In addition, the adaptor 400 further includes an extension portion 420, and the extension portion 420 is connected to an end of the clamping portion away from the battery cell body 200, so that the adaptor 400 is more flexibly connected to an external circuit structure.

It is realized that the thickness of the interposed portion is not less than the thickness of the extending portion 420. That is, the sum of the thicknesses of the first interposed portion 411 and the second interposed portion 412 is equal to or greater than the thickness of the extending portion 420. Specifically, one of the first and second sandwiching portions 411 and 412 is integrally formed with the extending portion 420, and then connected to the other of the first and second sandwiching portions 411 and 412. Thus, the preparation process is simple. Alternatively, the first clamping portion 411 and the second clamping portion 412 are integrally formed and then connected to the extension portion 420, or the first clamping portion 411, the second clamping portion 412 and the extension portion 420 are integrally formed and prepared.

It is realized that the thickness of the extension part 420 ranges from 0.01mm to 1 mm. Illustratively, the thickness of the extension portion 420 may be 0.01mm, 0.1mm, 0.3m, 0.5mm, 0.7mm, or 1mm, so as to avoid that the extension portion 420 is too thin, which results in a low strength of the adaptor 400, and also avoid that the extension portion 420 is too thick, which results in a large occupied internal space of the battery.

It can be realized that the length of the adaptor 400, in the direction of the extension length of the tab 310, ranges from 5mm to 100 mm. I.e., the sum of the lengths of the sandwiched portion and the extension portion 420 ranges from 5mm to 100 mm. This length of adaptor 400 can be 5mm, 10mm, 30m, 50mm, 70mm or 100mm etc to can avoid adaptor 400 to be too short, it is lower with outside circuit structure connection flexibility, can avoid adaptor 400 overlength again, lead to occupying battery inner space great.

It can be realized that the length of the adaptor 400 in a direction perpendicular to the extension length of the tab 310 ranges from 1mm to 80 mm. This length of adaptor 400 can be 1mm, 5mm, 10m, 30mm, 50mm or 80mm etc to can avoid adaptor 400 too narrow, it is lower with utmost point ear group 300's joint strength, can avoid adaptor 400 too wide again, lead to occupying battery inner space great.

It is realized that the extension length of each tab 310 ranges from 1mm to 30 mm. The extension length of each tab 310 can be 1mm, 5mm, 10mm, 15m, 20mm or 30mm, so that the tab 310 can be prevented from being too short, the connection strength between the tab 310 and the adaptor 400 is low, and the tab 310 can be prevented from being too long, so that the battery can occupy a large internal space.

It is realized that the length of each tab 310 ranges from 2mm to 60mm in a direction perpendicular to the extended length of the tab 310. This length of every utmost point ear 310 can be 2mm, 5mm, 10mm, 20m, 30mm, 40mm or 60mm etc. to can avoid utmost point ear 310 too narrow, lead to utmost point ear 310 and adaptor 400's joint strength lower, can avoid utmost point ear 310 too wide again, lead to occupying battery inner space great.

The tab group 300 having a plurality of tabs 310 will be described in detail below.

As shown in fig. 1, in the tab group 300 including a plurality of tabs 310, the tabs 310 are stacked in the thickness direction of the cell body 200, and the tab 310 closest to the first surface 210 among the tabs 310 is an outer tab 320. An end face of the pole lug group 300 facing the first face 210 can be connected to the adapter 400. In this case, if the extension length of the outer tab 320 is the same as that of the other tabs 310. The interposer 400 can only be connected to the first conductive layer 311 of the outer tab 320, but cannot be electrically connected to other conductive layers. If the interposer 400 includes the first clamping portion 411 and the second clamping portion 412, the first clamping portion 411 can only be connected to the first conductive layer 311 of the outer tab 320, and the second clamping portion 412 can only be connected to the second conductive layer 312 of the tab 310 closest to the second surface 220, but cannot be electrically connected to other conductive layers. The conduction ratio of the conductive layers in the tab group 300 is low, and the internal resistance of the battery cell 100 is high.

At least one of the remaining tabs 310 except for the outside tab 320 among the plurality of tabs 310 has an extended length greater than that of the outside tab 320. In this way, a portion of the conductive layer blocked by the insulating layer 313 of the outer tab 320 can be exposed, so that the adaptor 400 can be electrically connected to the exposed conductive layer, thereby reducing the internal resistance of the battery cell 100 and the battery.

The first sandwiched portion 411 is connected to at least a portion of the first conductive layer 311 in the tab set 300, and the exposed first conductive layers 311 in the tab set 300 may be connected to the first sandwiched portion 411. The second interposed portion 412 is connected to at least a portion of the second conductive layer 312 in the tab group 300, and the exposed second conductive layer 312 in the tab group 300 can be connected to the second interposed portion 412.

In some examples, in the tab group 300 including the plurality of tabs 310, the extending lengths of the plurality of tabs 310 sequentially increase in a direction from the first face 210 to the second face 220. The first interposed portion 411 is electrically connected to the first conductive layers 311 of all the tabs 310, the second conductive layer 312 of the tab 310 closest to the second surface 220 is electrically connected to the second interposed portion 412, and the second conductive layers 312 of the other tabs 310 are electrically connected to the first interposed portion 411 through the adjacent first conductive layers 311. In this way, all the conductive layers on the tabs 310 can be electrically connected to the adaptor 400, and the internal resistance of the battery cell 100 and the battery is low.

In other examples, as shown in fig. 2, in the tab group 300 including a plurality of tabs 310, the extending lengths of the plurality of tabs 310 sequentially increase and then decrease in the direction from the first surface 210 to the second surface 220. In this way, all the conductive layers in the tab set 300 can be electrically connected to the adaptor 400, so as to reduce the internal resistance of the battery cell 100 and the battery. In addition, the problem that the whole length of the pole lug group 300 is too large, so that the battery occupies a large internal space can be avoided.

Specifically, in the tab group 300, since the extension lengths of the tabs 310 are increased and then decreased, the tab 310 having the longest extension length is included in the tabs 310. The extending lengths of the portions of the tabs 310 located on the tabs 310 with the longest extending length and facing the first surface 210 sequentially increase along the direction from the first surface 210 to the second surface 220, the first clamping portion 411 may be connected to the first conductive layers 311 of the portions of the tabs 310, and the second conductive layers 312 of the portions of the tabs 310 may be connected to the first clamping portion 411 through the adjacent first conductive layers 311. The extending lengths of the portions of the tabs 310 located on the tabs 310 with the longest extending length and facing the second surface 220 sequentially increase along the direction from the second surface 220 to the first surface 210, the second clamping portions 412 may be connected to the second conductive layers 312 of the portions of the tabs 310, and the first conductive layers 311 of the portions of the tabs 310 are connected to the second clamping portions 412 through the adjacent second conductive layers 312.

In an embodiment in which the cell body 200 is a wound cell body, as shown in fig. 3, the pole piece 230 is in an unfolded state, i.e., the pole piece 230 is before winding. A plurality of tabs 310 are located at one end of pole piece 230 in the width direction, and the plurality of tabs 310 are arranged at intervals along the length direction of pole piece 230. The extending lengths of the tabs 310 sequentially increase and then decrease from one end to the other end of the pole piece 230 in the length direction.

It can be realized that, in the tab group 300 including a plurality of tabs 310, the difference between the extending lengths of every two adjacent tabs 310 is the same along the thickness direction of the cell body 200. Thus, the extending lengths of the tabs 310 are changed in an arithmetic progression, and the change is regular.

Specifically, in the tab group 300 including a plurality of tabs 310, the difference between the extending lengths of two adjacent tabs 310 along the thickness direction of the battery cell body 200 is in a range of 0.5mm to 10 mm. For example, the difference between the extension lengths of two adjacent tabs 310 may be 0.5mm, 1mm, 2mm, 3m, 5mm, 7mm, or 10mm, so as to prevent the extension lengths of two adjacent tabs 310 from being too close to each other and the conductive layer from being exposed, and prevent the extension length difference of two adjacent tabs 310 from being too large, which results in an excessively large overall length of the tab group 300 and a large occupied internal space of the battery.

It is realized that in the tab set 300 including the plurality of tabs 310, the number of tabs 310 ranges from 2 to 50. For example, the number of the tabs 310 may be 2, 3, 5, 11, 21, 31, 41, or 50, so as to avoid that the internal resistance of the battery is large due to too small number of the tabs 310, and to avoid that the internal space of the battery is large due to too large number of the tabs 310.

It is realized that the number of the tabs 310 is odd in each of the ear groups. Like this, along the thickness direction of electricity core body 200, can set up the utmost point ear 310 that extends the length the longest in utmost point ear group 300 at utmost point ear group 300's midmost, and the utmost point ear 310 quantity on the relative two sides of utmost point ear 310 that extends the length the longest equals for the terminal surface that is close to first face 210 of utmost point ear group 300 and the terminal surface that is close to second face 220 of utmost point ear group 300 are comparatively symmetrical.

In some embodiments, the clamping portion is welded to the tab group 300 and forms a welding stamp, and the welding stamp penetrates through the tab group 300 along a thickness direction of the tab group 300, wherein the number of tabs 310 through which the welding stamp can penetrate may be multiple, for example, the welding stamp may penetrate through a part of the number of tabs 310 in the tab group 300 or all of the tabs 310. One end of the solder print near the first surface 210 is connected to the first clamping portion 411, so that the first clamping portion 411 can electrically connect the plurality of tabs 310 penetrated by the solder print through the solder print. One end of the solder print near the second surface 220 is connected to the second clamping portion 412, so that the second clamping portion 412 can be electrically connected to the plurality of tabs 310 penetrated by the solder print through the solder print.

The present embodiment is described with the number of the tab groups 300 being two.

Specifically, the tab assembly 300 may include a first tab assembly and a second tab assembly, wherein the first tab assembly is electrically connected to the first tab assembly, and the second tab assembly is electrically connected to the second tab assembly. The first pole lug group is electrically connected with the first adaptor, and the second pole lug group is electrically connected with the second adaptor.

Namely, the first pole lugs on the first pole piece jointly form a first pole lug group, and the second pole lugs on the second pole piece jointly form a second pole lug group.

It can be realized that the first tab group includes a plurality of first tabs, and the plurality of first tabs are stacked in the thickness direction of the cell body 200; along the direction from the first surface 210 to the second surface 220, the extension lengths of the plurality of first tabs sequentially increase and then decrease. Therefore, all conducting layers of the first tabs are electrically connected with the first adapter, and the conducting proportion of the conducting layers in the first tab groups is 100%, so that the internal resistance of the battery cell 100 and the internal resistance of the battery are lower.

It can be realized that the second tab group includes a plurality of second tabs, and the plurality of second tabs are stacked in the thickness direction of the cell body 200; along the direction from the first surface 210 to the second surface 220, the extending lengths of the plurality of second tabs sequentially increase and then decrease. Therefore, all the conducting layers of the second tabs are electrically connected with the second adaptor, and the conducting proportion of the conducting layers in the second tab groups is 100%, so that the internal resistance of the battery cell 100 and the internal resistance of the battery are lower.

One specific implementation is as follows:

the current collector 231 of the positive plate adopts an aluminized film, the thickness of the insulating layer 313 is 8 microns, the thickness of the aluminum layer is 1 micron, and the total thickness of the current collector 231 of the positive plate is 10 microns; the current collector 231 of the negative plate adopts a copper-plated film, the thickness of the insulating layer 313 is 3 μm, the thickness of the copper layer is 1 μm, and the total thickness of the current collector 231 of the negative plate is 5 μm. Through processes of stirring, coating, rolling, slitting and the like, the number of the positive lugs is 7 when the current collector 231 of the positive plate is subjected to die cutting, the extending lengths of the positive lugs are respectively 5mm, 6mm, 7mm, 8mm, 7mm, 6mm and 5mm from one end to the other end of the positive plate in the length direction, and the length value of each positive lug in the length direction of the positive plate is 10 mm. The length of the clamping portion of the adaptor 400 is 10mm, the thicknesses of the first clamping portion 411 and the second clamping portion 412 are 0.2mm and 0.1mm respectively, the length of the extension portion 420 is 10mm, and the thickness of the extension portion 420 is 0.2 mm. The adaptor 400 is joined to the tab set 300 formed of a plurality of positive tabs by ultrasonic welding.

It should be noted that the numerical values and numerical ranges related to the embodiments of the present application are approximate values, and there may be a certain range of errors depending on the manufacturing process, and the error may be considered as negligible by those skilled in the art.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. An electric core is characterized by comprising an electric core body, an adapter and a pole lug group, wherein the pole lug group comprises a plurality of pole lugs which are arranged in a stacking mode along the thickness direction of the electric core body, the adapter is respectively connected with at least part of the pole lugs in the pole lug group, each pole lug comprises an insulating layer, a first conducting layer and a second conducting layer, and the first conducting layer and the second conducting layer respectively cover two opposite surfaces of the insulating layer;

the battery cell body comprises a first surface and a second surface which are opposite to each other in the thickness direction;

in the pole lug group, the pole lug closest to the first surface in the pole lugs is an outer side pole lug, and the extension length of at least one of the pole lugs except the outer side pole lug is greater than that of the outer side pole lug.

2. The cell of claim 1, wherein in the tab group, the extension lengths of the tabs sequentially increase and then decrease in a direction from the first face to the second face.

3. The electrical core of claim 1, wherein in the tab group, the extended lengths of a plurality of the tabs sequentially increase in a direction from the first face to the second face.

4. The cell of any of claims 1 to 3,

the thickness of the insulating layer is not more than 20 μm;

and/or the thickness of the first conductive layer is not more than 5 μm;

and/or the thickness of the second conductive layer is not more than 5 μm;

and/or the extension length of each tab ranges from 1mm to 30 mm;

and/or the length of each tab along the direction perpendicular to the extending length ranges from 2mm to 60 mm;

and/or in the pole lug group, along the thickness direction of the battery cell body, the difference value of the extension length of each two adjacent pole lugs is the same;

and/or in the pole lug group, along the thickness direction of the battery core body, the difference of the extension lengths of two adjacent pole lugs ranges from 0.5mm to 10 mm;

and/or, in the pole ear group, the number of the pole ears ranges from 2 to 50;

and/or, in the pole lug group, the number of the pole lugs is odd.

5. The electric core according to any of claims 1 to 3, wherein the adaptor comprises a clamping portion, and the clamping portion comprises a first clamping portion and a second clamping portion which are connected and arranged oppositely;

the first portion of establishing that presss from both sides with the orientation of utmost point ear group the terminal surface of first face is connected, the second press from both sides the portion of establishing with the orientation of utmost point ear group the terminal surface of second face is connected.

6. The battery cell of claim 5, wherein the first conductive layer is disposed on a surface of the tab facing the first surface, the second conductive layer is disposed on a surface of the tab facing the second surface, the first clamping portion is connected to at least a portion of the first conductive layer in the tab group, and the second clamping portion is connected to at least a portion of the second conductive layer in the tab group;

and/or, press from both sides the portion of establishing with utmost point ear group welding and form and weld the seal, weld the seal along the thickness direction of utmost point ear group runs through utmost point ear group, weld the seal and be close to the one end of first face with first clamp portion is connected, weld the seal and be close to the one end of second face with the second presss from both sides the portion of establishing and connects.

7. The battery cell of claim 5, wherein the adaptor further comprises an extension portion, and the extension portion is connected to an end of the clamping portion facing away from the battery cell body;

wherein the content of the first and second substances,

the thickness of the clamping part is not less than that of the extension part;

and/or the extension has a thickness in the range of 0.01mm to 1 mm;

and/or, along the direction of the extension length, the length range of the adapter is 5mm-100 mm;

and/or the length of the adapter piece in the direction perpendicular to the extension length ranges from 1mm to 80 mm.

8. The battery cell of any of claims 1 to 3, wherein the battery cell body comprises a first pole piece and a second pole piece that are stacked on each other and have opposite polarities, and a separator is disposed between the first pole piece and the second pole piece; the pole lug group comprises a first pole lug group and a second pole lug group, the first pole piece is electrically connected with the first pole lug group, and the second pole piece is electrically connected with the second pole lug group;

the first pole lug group comprises a plurality of first pole lugs, and the first pole lugs are stacked along the thickness direction of the battery cell body; along the direction from the first surface to the second surface, the extension lengths of the first tabs are sequentially increased and then decreased;

and/or the second pole lug group comprises a plurality of second pole lugs, and the second pole lugs are stacked along the thickness direction of the battery cell body; and along the direction from the first surface to the second surface, the extension lengths of the second tabs are sequentially increased and then decreased.

9. The battery cell of claim 8, wherein the first pole piece and the second pole piece are both one, and the first pole piece, the diaphragm and the second pole piece, which are stacked in sequence, are wound around a winding center to form a winding structure; the first pole piece is provided with a plurality of first pole lugs; and/or a plurality of second tabs are arranged on the second pole piece;

or, the first pole piece and the second pole piece are both multiple, the multiple first pole pieces and the multiple second pole pieces are sequentially staggered and stacked in the same direction, and the diaphragm is arranged between every two adjacent first pole pieces and second pole pieces; each first pole piece is provided with one first pole lug, and each second pole piece is provided with one second pole lug.

10. A battery comprising a cell according to any of claims 1 to 9.

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