Multi-tab cell and battery

Abstract

Disclosed in the present application are a multi-tab cell and a battery. The multi-tab cell comprises: a first electrode sheet; a second electrode sheet, wherein the first electrode sheet and the second electrode sheet are stacked and wound to form a cell, the first electrode sheet and the second electrode sheet each comprise an electrode sheet main body and a plurality of empty-foil areas, which are arranged at intervals on one side of the electrode sheet main body in the length direction of the electrode sheet main body, the empty-foil areas on the first electrode sheet are stacked to form a first conduction portion, and the empty-foil areas on the second electrode sheet are stacked to form a second conduction portion; and two tabs, which have opposite polarities and are electrically connected to the first electrode sheet and the second electrode sheet, respectively, wherein at least one of the empty-foil areas in the first conduction portion and / or the second conduction portion is a first empty-foil area, and the remaining empty-foil areas are second empty-foil areas, each first empty-foil area has an extension portion extending outwards in the length direction, and the extension portion can cover at least some of the second empty-foil areas. By means of the multi-tab cell of the present application, a plurality of empty-foil areas can be effectively fixed.

Description

Multi-tab cells and batteries Technical Field

[0001] The present application belongs to the field of new energy battery technology, and in particular relates to a multi-tab battery cell and a battery. Background Art

[0002] Soft-pack lithium-ion batteries are widely used in various digital products and mobile devices. With each successive generation of these products, the demands on the battery's range and charging speed have become increasingly stringent. Typical fast-charging cells feature multiple tabs. For applications requiring particularly high charge rates, these multiple tabs are used to reduce impedance and increase charging and discharging speeds.

[0003] Whether it is a wound multi-electrode structure or a laminated multi-electrode structure, multiple empty foil areas are required on the electrode. After the multiple layers of empty foil areas are stacked and welded together, the layers of electrode plates are connected to increase the charging and discharging speed. However, when the multiple layers of empty foil areas are wound or laminated, the holes in the foil areas of each layer may not be completely aligned. If the alignment is not high, welding may not be able to proceed properly, and the layers of electrode plates will not be able to connect properly.

[0004] Summary of the Invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a multi-tab battery cell that can effectively fix multiple layers of empty foil areas, eliminate their alignment deviation, and ensure connectivity between the multiple layers of empty foil areas.

[0006] This application also proposes another multi-electrode battery cell;

[0007] The present application also proposes a battery using the above-mentioned multi-electrode battery cell.

[0008] The multi-electrode battery cell according to the first embodiment of the present application includes:

[0009] First pole piece;

[0010] A second pole piece, wherein the first pole piece and the second pole piece are stacked and wound to form a battery core, wherein the first pole piece and the second pole piece each have a pole piece body and a plurality of hollow foil areas spaced apart along the length direction of the pole piece body on one side of the pole piece body, wherein the hollow foil areas on the first pole piece are stacked to form a first conductive portion, and the hollow foil areas on the second pole piece are stacked to form a second conductive portion;

[0011] Two pole tabs, the two pole tabs having opposite polarities and electrically connected to the first pole piece and the second pole piece respectively;

[0012] In which, at least one of the empty foil areas in the first conductive portion and / or the second conductive portion is defined as a first empty foil area, and the remaining empty foil areas are defined as second empty foil areas. The first empty foil area has an extension portion extending along the length direction, and the extension portion can cover at least a portion of the second empty foil area.

[0013] The multi-electrode battery cell according to the embodiment of the present application has at least the following beneficial effects:

[0014] The multi-pole battery cell has a first electrode piece and a second electrode piece. The two electrode pieces with opposite polarities are stacked and wound to form a battery cell. The empty foil areas on the first electrode piece are stacked and connected to form a first conductive part, and the empty foil areas on the second electrode piece are stacked and connected to form a second conductive part. The first electrode pieces of each layer are connected and the second electrode pieces of each layer are connected, so that fast charging and discharging can be achieved. There is a first empty foil area in the first conductive part and the second conductive part. The first empty foil area can wrap at least part of the second empty foil area, so that when multiple empty foil areas are superimposed, even if the alignment degree is not high, the alignment error can be covered, and the empty foil area can be effectively fixed to improve welding stability.

[0015] In other embodiments of the present application, the first empty foil area is located on the outside of the battery cell in the thickness direction.

[0016] In other embodiments of the present application, the number of the first empty foil areas is two, and the two first empty foil areas are respectively located on both sides of the battery core in the thickness direction.

[0017] In other embodiments of the present application, along the length direction, both sides of the first empty foil area have the extension portion.

[0018] In other embodiments of the present application, along the width direction of the pole piece body, the width of the extension portion is smaller than the width of the second empty foil area, and the extension portion is arranged at an end of the first empty foil area relatively away from the pole piece body; or, along the width direction of the pole piece body, the width of the extension portion is equal to the width of the second empty foil area.

[0019] In other embodiments of the present application, the first conductive portion, the second conductive portion, and the two tabs are all located on the same side of the battery cell.

[0020] The multi-electrode battery cell according to the second embodiment of the present application includes:

[0021] a plurality of first pole pieces;

[0022] a plurality of second pole pieces, wherein the first pole pieces and the second pole pieces are alternately stacked to form a battery cell, wherein each of the first pole pieces and the second pole pieces comprises a pole piece body and a hollow foil area located on one side of the pole piece body, wherein the hollow foil areas on each of the first pole pieces are stacked to form a first conductive portion, and the hollow foil areas on each of the second pole pieces are stacked to form a second conductive portion;

[0023] Two pole tabs, the two pole tabs having opposite polarities and respectively connected to one of the first pole pieces and one of the second pole pieces;

[0024] Wherein, the first conductive portion, and / or at least one of the empty foil areas in the second conductive portion is defined as a first empty foil area, and the rest are second empty foil areas, the first empty foil area has an extension portion extending along the width direction of the electrode body, and the extension portion can cover at least a portion of the second empty foil area.

[0025] In other embodiments of the present application, the first empty foil area is located on the outside of the battery cell in the thickness direction.

[0026] In other embodiments of the present application, the number of the first empty foil areas is two, and the two first empty foil areas are respectively located on both sides of the battery core in the thickness direction.

[0027] In other embodiments of the present application, along the length direction of the pole piece body, the width of the extension portion is smaller than the width of the second empty foil area, and the extension portion is arranged at an end of the first empty foil area relatively away from the pole piece body; or, along the length direction of the pole piece body, the width of the extension portion is equal to the width of the second empty foil area.

[0028] A battery according to a third embodiment of the present application includes:

[0029] The above-mentioned multi-pole battery cell.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0032] FIG1 is a schematic diagram of a multi-tab battery cell according to an embodiment of the present application;

[0033] FIG2 is a schematic diagram of the unfolding of the first pole piece in an embodiment of one aspect of the present application;

[0034] FIG3 is a schematic diagram of an unfolded first pole piece in another embodiment of the present application;

[0035] FIG4 is a schematic diagram of an unfolded first pole piece in another embodiment of the present application;

[0036] FIG5 is a schematic diagram of an unfolded first pole piece in another embodiment of the present application;

[0037] FIG6 is a schematic diagram of a multi-tab battery cell according to another embodiment of the present application;

[0038] FIG7 is a schematic diagram of the unfolding of the first pole piece in another embodiment of the present application;

[0039] FIG8 is a schematic diagram of the unfolding of the first pole piece in another embodiment of the present application.

[0040] Reference numerals: first pole piece 100 , pole piece body 110 , hollow foil area 120 , first hollow foil area 121 , extension portion 1211 , second hollow foil area 122 ; first conductive portion 200 ; second conductive portion 300 ; pole tab 400 . DETAILED DESCRIPTION

[0041] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0042] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0043] In the description of this application, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0044] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0045] In the description of this application, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0046] The present application proposes a multi-electrode battery cell and a battery, wherein the multi-electrode battery cell has a first electrode piece and a second electrode piece, and the two electrode pieces with opposite polarities constitute the battery cell, and the battery cell also has a first conductive portion and a second conductive portion, which connect the first electrode pieces of each layer and the second electrode pieces of each layer, so as to achieve fast charging and discharging, and at least one of the first conductive portion and the second conductive portion has a first empty foil area, and the first empty foil area has an extension portion. When the battery cell is formed, the extension portion can wrap at least a portion of the second empty foil area, so that when multiple empty foil areas are superimposed, even if the alignment is not high, the alignment error can be covered, and the multiple layers of empty foil areas can be effectively fixed to improve welding stability. In order to achieve the above-mentioned purpose, the multi-electrode battery cell proposed in the present application includes a first electrode piece and a second electrode piece with empty foil areas, and multiple empty foil areas are stacked and connected to form a first conductive portion and a second conductive portion arranged at intervals, each empty foil area has at least one first empty foil area, and the rest are second empty foil areas, and the first empty foil area has an extension portion that can wrap at least a portion of the second empty foil area, so as to effectively fix it and cover the alignment error.

[0047] In some embodiments, referring to Figures 1 to 5 , the multi-tab battery cell proposed in this application includes a first pole piece 100, a second pole piece, and two pole pieces 400 of opposite polarity. The first pole piece 100 and the second pole piece are stacked and wound to form a battery cell. The first pole piece 100 and the second pole piece each include a pole piece body 110 and a plurality of hollow foil areas 120. Referring to Figures 2 to 5 , the first pole piece 100 and the second pole piece have opposite polarities, that is, one is a positive pole piece and the other is a negative pole piece. The two have similar structures. Here, we take the first pole piece 100 as an example for explanation. The first pole piece 100 includes a pole piece body 110 and a plurality of empty foil areas 120. The plurality of empty foil areas 120 are spaced apart on one side of the pole piece body 110 along the length direction of the pole piece body 110. When the first pole piece 100 and the second pole piece are stacked and wound, the plurality of empty foil areas 120 on the first pole piece 100 are stacked and connected to form a first conductive portion 200, and the plurality of empty foil areas 120 on the second pole piece are stacked and connected to form a second conductive portion 300.

[0048] It should be noted that the pole piece body 110 of the first pole piece 100 generally has an active coating, and the pole piece body 110 of the second pole piece also has an active coating. The first pole piece 100 and the second pole piece are stacked and wound to form multiple layers. When the first pole piece 100 and the second pole piece are stacked and wound, the active coatings on the first pole piece 100 and the second pole piece need to be set accordingly, and a diaphragm is generally provided between the first pole piece 100 and the second pole piece. The size of the diaphragm corresponds to the active coating to ensure that the charging and discharging functions are normally realized after the battery cell is formed. And the two pole tabs 400 of opposite polarity are electrically connected to the first pole piece 100 and the second pole piece respectively (the two pole tabs 400 of opposite polarity are also the positive pole tab and the negative pole tab, which are respectively connected to the positive pole piece and the negative pole piece). During the charge and discharge process, the current is introduced into the first pole piece 100 and the second pole piece through the positive pole tab and the negative pole tab. Because the empty foil area 120 on each layer of the first pole piece 100 is connected, the empty foil area 120 on each layer of the second pole piece is also connected, which can make the charge and discharge current of each layer synchronized and uniform, achieving the effect of fast charging of the current general multi-pole tab process. And compared with the existing multi-pole tab structure battery cell, there is no need to perform transfer welding and other processes on the pole tab 400 and the multi-pole tab, making it simpler to manufacture.

[0049] 2 to 5 , the first electrode 100 in the unfolded state is shown in the figure, and has a plurality of empty foil areas 120 spaced apart along the length direction of the electrode body 110. For the convenience of description, we define at least one empty foil area 120 on the first electrode 100 as a first empty foil area 121, and the remaining empty foil areas 120 as second empty foil areas 122 (the second electrode and the first electrode 100 have similar structures, and here we only take the first electrode 100 as an example for illustration). Among them, the first empty foil area 121 has an extension portion 1211 extending along the length direction. When the first electrode 100 and the second electrode are wound to form a battery cell, the extension portion 1211 on the first empty foil area 121 can cover at least part of the second empty foil area 122. It can be understood that the first empty foil area 121 is provided with an extension portion 1211, and the extension portion 1211 extends along the length direction. When the battery cell is wound, the first empty foil area 121 and the second empty foil area 122 are stacked, and the extension portion 1211 can wrap the multiple second empty foil areas 122 after stacking. Therefore, even if the alignment between the multiple empty foil areas 120 is not high, the extension portion 1211 can cover the alignment error and effectively fix the multiple second empty foil areas 122. When the multiple empty foil areas 120 are connected (generally by welding), the stability of the connection can be improved, ensuring that the first conductive portion 200 can connect each layer of the first electrode 100, and ensuring the normal use of the multi-electrode tab 400 battery cell.

[0050] In some embodiments, referring to FIG1 , a plurality of empty foil areas 120 are stacked into a first conductive portion 200 and a second conductive portion 300. In the thickness direction of the battery cell, the first empty foil area 121 is at least one empty foil area 120 on the outside in the thickness direction. It can be understood that the first empty foil area 121 is located on the outside in the thickness direction of the battery cell and can wrap as many of the remaining second empty foil areas 122 as possible, that is, the second empty foil areas 122 can be aligned and effectively fixed by the extension portion 1211 to connect them and form a conductive portion.

[0051] It should be noted that, with reference to Figures 2 to 5, in some embodiments, the first empty foil area 121 is generally provided as two, and the two first empty foil areas 121 are the first electrode 100, and / or the two second electrode sheets away from the winding center (i.e., the two rightmost electrodes in the illustrated electrode sheet, and the left side of the illustrated electrode sheet is the winding center). It can be understood that, in a battery cell with a wound structure, the two first empty foil areas 121 away from the winding center are located on both sides of the thickness direction of the battery cell after winding, i.e., the bottom fold and the top fold of the multi-layer electrode sheet. It can be understood that, with such a configuration, when the battery cell is formed, the extensions 1211 on the two first empty foil areas 121 can wrap the multiple second empty foil areas 122 from both sides, thereby further ensuring that the multiple empty foil areas 120 are aligned and effectively fixed to ensure that subsequent welding can proceed normally, and the first conductive portion 200 and the second conductive portion 300 can connect the multi-layer electrode sheets.

[0052] It can also be understood that the number of the first empty foil areas 121 is not limited thereto. By providing a plurality of first empty foil areas 121 , when the battery cell is wound and formed, multiple layers of extension portions 1211 can be formed and stacked to wrap the multiple empty foil areas 120 , thereby further ensuring connectivity between the multiple layers of empty foil areas 120 .

[0053] 2 , 4 and 5 , along the length direction of the electrode body 110 , both sides of the first empty foil area 121 have extension portions 1211 . It can be understood that when the first electrode 100 and the second electrode are wound to form a battery cell, the multiple empty foil areas 120 on the first electrode 100 are stacked and connected to form a first conductive portion 200 , and the multiple empty foil areas 120 on the second electrode are stacked and connected to form a second conductive portion 300 . The extension portion 1211 on the first empty foil area 121 can wrap the second empty foil area 122 after at least part of the stacking. Along the length direction of the electrode body 110, the extension portion 1211 is provided on both sides of the first empty foil area 121. After the plurality of empty foil areas 120 are stacked, the extension portion 1211 on the first empty foil area 121 can wrap the plurality of second empty foil areas 122 from both sides in the length direction of the electrode body 110, so as to better fix the plurality of second empty foil areas 122. Even if the alignment of each second empty foil area 122 is not enough, it can be fixed from both sides to cover its alignment error, and then welding is performed to connect the plurality of empty foil areas 120, thereby ensuring that each empty foil area 120 can be effectively connected and the rapid charging and discharging of the battery can be carried out normally.

[0054] It should be noted that, in some embodiments, referring to Figure 3, along the length direction of the electrode body 110, the first empty foil area 121 has an extension portion 1211 on only one side, and the length of the extension portion 1211 is not limited. It can only wrap part of the second empty foil area 122, or it can be set to be longer to wrap all the empty foil areas 120 therein, so as to further ensure that even if the alignment of multiple empty foil areas 120 is not enough, the extension portion 1211 can wrap multiple layers of empty foil areas 120 therein, so that the multiple empty foil areas 120 are close together and aligned, welding can be better carried out, and it is ensured that the multiple empty foil areas 120 can be better connected.

[0055] In some embodiments, referring to FIG2 , along the length direction of the electrode body 110, both sides of the first empty foil area 121 have extensions 1211, along the width direction of the electrode body 110, the widths of the two extensions 1211 are smaller than the widths of the second empty foil area 122, and the two extensions 1211 are both arranged at one end of the first empty foil area 121 away from the electrode body 110. It can be understood that when the first electrode 100 and the second electrode are wound into a battery cell, the two extensions 1211 on the first empty foil area 121 can wrap the multiple second empty foil areas 122 from both sides, thereby covering To cover the alignment error, at the same time, the design of the "T"-shaped first empty foil area 121 can wrap the multiple empty foil areas 120 from both sides, and referring to Figure 1, the width of the two extensions 1211 is smaller than the width of the second empty foil area 122, and the multiple second empty foil areas 122 are wrapped from both sides. It can be understood that even if the alignment between the multiple empty foil areas 120 is not enough, the multiple empty foil areas 120 can be gathered and effectively fixed by wrapping them from the side away from the electrode body 110, so that subsequent welding can be better carried out, thereby ensuring the connectivity between the multiple empty foil areas 120.

[0056] In some embodiments, referring to Figures 4 and 5, along the width direction of the electrode body 110, the width of the extension portion 1211 is equal to the width of the second empty foil area 122. It can be understood that the width of the extension portion 1211 is equal to the width of the second empty foil area 122. After multiple empty foil areas 120 are stacked, the extension portion 1211 can completely cover at least a portion of the second empty foil area 122 from the width direction of the electrode body 110 (when the length of the extension portion 1211 is sufficient, it can cover all of the second empty foil areas 122). When the extension portion 1211 can completely cover the second empty foil area 122, even if the second empty foil areas 122 are not aligned and have deviations, the deviations between the second empty foil areas 122 can be eliminated, so that the second empty foil areas 122 are aligned, that is, the alignment between the empty foil areas 120 is ensured, so that they are aligned, thereby ensuring normal welding and normal communication between the empty foil areas 120.

[0057] In some embodiments, the battery cell generally needs to be placed in a battery shell, and it is also necessary to inject electrolyte into the shell before it can be used normally. The battery cell proposed in this application arranges the first conductive part 200, the second conductive part 300 and the two pole ears 400 on the same side of the battery cell. After the battery cell is placed in the shell, only the pole body 110 will react with the electrolyte for charging and discharging. The two pole ears 400 and the first conductive part 200 and the second conductive part 300 are arranged on the same side of the battery cell. When the battery cell is placed in the shell, the space occupied will be less. The shell of the same volume can accommodate more space for the battery cell body, that is, the energy density of the battery will be higher.

[0058] In some embodiments, referring to Figures 2 to 5, along the length direction of the first pole piece 100, the pole tab 400 is connected to the middle position of the pole piece body 110 in the length direction, and / or, along the length direction of the second pole piece, the pole tab 400 is connected to the middle position of the pole piece body 110 in the length direction. It can be understood that both the first pole piece 100 and the second pole piece have a large length. During the charge and discharge process, they are connected to the outside world through the positive pole tab and the negative pole tab. The current interacts with the outside world through the positive pole tab and the negative pole tab. On the pole piece body 110, there is an active coating. The pole tab 400 is set in the middle position of the pole piece body 110. During charge and discharge, the active materials at various positions on the first pole piece 100 and the second pole piece are not too far away from the pole piece. The current can quickly reach various positions of the pole piece, thereby further improving the charge and discharge rate of the battery.

[0059] It should be noted that, in other embodiments, along the length direction of the first pole piece 100, the pole tab 400 is connected to the edge position of the pole piece body 110 in the length direction, and / or, along the length direction of the second pole piece, the pole tab 400 is connected to the edge position of the pole piece body 110 in the length direction. Correspondingly, a blank area is provided at the edge position of the first pole piece 100, and / or, a blank area is provided at the edge position of the second pole piece. The pole tab 400 can be directly connected to the blank area, thereby eliminating the need to process the active coating area of ​​the pole piece, thereby simplifying the production and processing steps.

[0060] According to the multi-electrode battery cell proposed in the embodiment of the second aspect of the present application, it includes a plurality of first pole pieces 100 and a plurality of second pole pieces, wherein each first pole piece 100 includes a pole piece body 110 and an empty foil area 120, and the pole piece body 110 has an active coating, and each second pole piece includes a pole piece body 110 and an empty foil area 120, and the pole piece body 110 also has an active coating, and the battery cell also has two pole pieces 400 with opposite polarity, namely a positive pole piece and a negative pole piece, wherein one pole piece 400 is electrically connected to one of the first pole pieces 100, and the other pole piece 400 is electrically connected to one of the second pole pieces. Referring to Figures 7 and 8, in the illustrated embodiment, the left side is a first pole piece 100 connected to the pole piece 400, and the right side is a first pole piece 100 not connected to the pole piece 400. It can be understood that there is only one first pole piece 100 connected to the pole piece 400, and there can be multiple first pole pieces 100 not connected to the pole piece 400. The same is true for the second electrode piece. The electrode tab 400 is electrically connected to one of the second electrode pieces. There are multiple second electrode pieces that are not connected to the electrode tab 400. In addition, generally, the number of first electrode pieces 100 and second electrode pieces corresponds to each other, and each first electrode piece 100 and second electrode piece is alternately stacked to form a battery cell.

[0061] It should be noted that the first electrode sheets 100 and the second electrode sheets are alternately stacked to form a battery cell. The hollow foil areas 120 on the first electrode sheets 100 are stacked and connected to form a first conductive portion 200. The hollow foil areas 120 on the second electrode sheets are stacked and connected to form a second conductive portion 300. To prevent short circuits within the battery cell, the first conductive portion 200 and the second conductive portion 300 are generally spaced apart and are generally coated with insulating glue.

[0062] It can be understood that when the first electrode sheet 100 and the second electrode sheet are alternately stacked, the active coatings on the two electrode sheets need to be set accordingly, and a diaphragm is generally provided between the adjacent first electrode sheets 100 and the second electrode sheets. The length and width of the diaphragm correspond to the size of the active coating on the first electrode sheet 100 and the active coating on the second electrode sheet to realize the charging and discharging function of the battery cell. After being connected, the multiple layers of empty foil areas 120 form a first conductive portion 200 and a second conductive portion 300. In addition, on one of the first pole pieces 100, there is also a pole ear 400 that is directly electrically connected to the first pole piece 100, and on one of the second pole pieces, there is also a pole ear 400 that is directly electrically connected to the second pole piece (the two pole ears 400 are generally a positive pole ear and a negative pole ear, respectively). During the charge and discharge process, the current is introduced into the first pole piece 100 and the second pole piece through the positive pole ear and the negative pole ear. Because the empty foil area 120 on each layer of the first pole piece 100 is connected, the empty foil area 120 on each layer of the second pole piece is also connected, which can make the charge and discharge current of each layer synchronized and uniform, achieving the effect of fast charging of the current general multi-pole ear process. And compared with the existing multi-pole ear structure battery cell, there is no need to perform transfer welding and other processes on the pole ear 400 and the multi-pole ear, making it simpler to manufacture.

[0063] It should be noted that, for the convenience of description, along the thickness direction of the battery cell, we define the first conductive portion 200, and / or, at least one empty foil area 120 on the second conductive portion 300 as a first empty foil area 121, and the rest are second empty foil areas 122. The first empty foil area 121 has an extension portion 1211 extending along the width direction of the electrode body 110. When the first electrode 100 and the second electrode are stacked into a battery cell, the extension portion 1211 can cover at least part of the second empty foil area 122. It can be understood that, with reference to Figure 6, When the first electrode piece 100 and the second electrode piece are stacked into a battery cell, multiple empty foil areas 120 are stacked, and the extension portion 1211 of the first empty foil area 121 can wrap at least part of the second empty foil area 122. Even if the alignment between the multiple empty foil areas 120 is not enough, the multiple empty foil areas 120 can be effectively fixed, and subsequent welding is facilitated to proceed normally, ensuring that the first conductive portion 200 and the second conductive portion 300 can be smoothly formed, and each layer of the first electrode piece 100 can be connected to each other, and each layer of the second electrode piece can also be connected to each other.

[0064] In some embodiments, referring to Figure 6, multiple empty foil areas 120 are stacked into a first conductive portion 200 and a second conductive portion 300. In the thickness direction of the battery cell, the first empty foil area 121 is at least one empty foil area 120 on the outside in the thickness direction. It can be understood that the first empty foil area 121 is located on the outside in the thickness direction of the battery cell and can wrap the remaining second empty foil areas 122 as much as possible, that is, the respective second empty foil areas 122 can be aligned and effectively fixed by the extension portion 1211 to connect them to form a conductive portion.

[0065] It should be noted that, with reference to Figures 7 and 8, in some embodiments, two first empty foil areas 121 are generally provided, that is, a first electrode sheet 100 having a first empty foil area 121, and / or two second electrode sheets. When each first electrode sheet 100 and each second electrode sheet are alternately stacked, the two first electrode sheets 100 having the first empty foil area 121 are respectively located above and below in the thickness direction of the battery cell, and the same applies to the second electrode sheet. It can be understood that in a battery cell with a laminated structure, the two first electrode sheets 100 having the first empty foil area 121 are respectively located on both sides in the thickness direction of the battery cell, that is, the bottommost and topmost of the multiple layers of first electrode sheets 100. With this arrangement, when the battery cell is formed, the extensions 1211 on the two first empty foil areas 121 can wrap around the multiple second empty foil areas 122 from both sides, thereby further ensuring that the multiple empty foil areas 120 are aligned and effectively fixed, ensuring that subsequent welding can proceed normally, and the first conductive portion 200 and the second conductive portion 300 can connect the multiple layers of electrode sheets.

[0066] It can also be understood that the number of the first empty foil areas 121 is not limited thereto. Multiple first empty foil areas 121 are provided. When the first pole pieces 100 and the second pole pieces are alternately stacked to form a battery cell, a multi-layer extension portion 1211 can be formed to wrap the multiple empty foil areas 120 after stacking, thereby further ensuring the connectivity between the multiple layers of empty foil areas 120.

[0067] 6 to 8 , along the width direction of the electrode body 110 , both sides of the first empty foil area 121 have an extension portion 1211 . It can be understood that when each first electrode 100 and each second electrode are alternately stacked to form a battery cell, the multiple empty foil areas 120 on each first electrode 100 are stacked and connected to form a first conductive portion 200 , and the multiple empty foil areas 120 on each second electrode are stacked and connected to form a second conductive portion 300 . The extension portion 1211 on the first empty foil area 121 can wrap the second empty foil area 122 after at least part of the stacking. Along the width direction of the electrode body 110, the extension portion 1211 is provided on both sides of the first empty foil area 121. After the multiple empty foil areas 120 are stacked, the extension portion 1211 on the first empty foil area 121 can wrap the multiple second empty foil areas 122 from both sides in the width direction of the electrode body 110, so as to better fix the multiple second empty foil areas 122. Even if the alignment of each second empty foil area 122 is not enough, it can be fixed from both sides to cover its alignment error, and then welding is performed to connect the multiple empty foil areas 120, thereby ensuring that each empty foil area 120 can be effectively connected and the rapid charging and discharging of the battery can be carried out normally.

[0068] It should be noted that, in some embodiments, along the width direction of the electrode body 110, the first empty foil area 121 has an extension portion 1211 on only one side, and the length of the extension portion 1211 is not limited. It can only wrap part of the second empty foil area 122, or it can be set longer to wrap all the empty foil areas 120 therein, so as to further ensure that even if the alignment of multiple empty foil areas 120 is not enough, multiple layers of empty foil areas 120 can be wrapped therein, so that the multiple empty foil areas 120 are brought close and aligned, so that they can be better connected.

[0069] In some embodiments, referring to FIG7 , along the width direction of the electrode body 110, both sides of the first empty foil area 121 have extensions 1211, along the length direction of the electrode body 110, the width of the two extensions 1211 is less than the width of the second empty foil area 122, and the two extensions 1211 are both arranged at one end of the first empty foil area 121 away from the electrode body 110. It can be understood that when each first electrode 100 and each second electrode are alternately stacked into a battery cell, the two extensions 1211 on the first empty foil area 121 can wrap the multiple second empty foil areas 122 from both sides, thereby And cover its alignment error. At the same time, the design of the "T"-shaped first empty foil area 121 can wrap multiple empty foil areas 120 from both sides, and referring to Figure 6, the width of the two extensions 1211 is smaller than the width of the second empty foil area 122, and the multiple second empty foil areas 122 are wrapped from both sides. It can be understood that even if the alignment between the multiple empty foil areas 120 is not enough, the multiple empty foil areas 120 can be gathered and effectively fixed by wrapping them from the side away from the electrode body 110, so that subsequent welding can be better carried out, thereby ensuring the connectivity between the multiple empty foil areas 120.

[0070] In some embodiments, referring to Figure 8, along the length direction of the electrode body 110, the width of the extension portion 1211 is equal to the width of the second empty foil area 122. It can be understood that the width of the extension portion 1211 is equal to the width of the second empty foil area 122. After multiple empty foil areas 120 are stacked, the extension portion 1211 can completely cover at least a portion of the second empty foil area 122 from the width direction of the electrode body 110 (when the length of the extension portion 1211 is sufficient, it can cover all of the second empty foil areas 122). When the extension portion 1211 can completely cover the second empty foil area 122, even if the second empty foil areas 122 are not aligned and have deviations, the deviations between the second empty foil areas 122 can be eliminated, so that the second empty foil areas 122 are aligned, that is, the alignment between the empty foil areas 120 is ensured, so that they are aligned, thereby ensuring normal welding and normal communication between the empty foil areas 120.

[0071] In some embodiments, the battery cell proposed in the present application arranges the first conductive part 200, the second conductive part 300 and the two tabs 400 on the same side of the battery cell. When the battery cell is placed in the shell, the space occupied will be less. The shell of the same volume can accommodate more space for the battery cell body, that is, the energy density of the battery will be higher.

[0072] According to the battery proposed in the embodiment of the third aspect of the present application, including the above-mentioned multi-pole battery cell, it should be noted that the battery has a shell, the shell defines a cavity for accommodating the battery cell, the battery cell is placed in the shell, and then the electrolyte is injected into the shell. The positive and negative pole ears on the battery cell are correspondingly connected to the positive and negative pole posts on the shell to form a battery that can be used normally.

[0073] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application and the features of the embodiments can be combined with each other unless there is a conflict.

Claims

1. Multi-pole battery cells, including: First pole piece; A second pole piece, wherein the first pole piece and the second pole piece are stacked and wound to form a battery core, wherein the first pole piece and the second pole piece each have a pole piece body and a plurality of empty foil areas spaced apart along the length direction of the pole piece body on one side of the pole piece body, wherein the empty foil areas on the first pole piece are stacked to form a first conductive portion, and the empty foil areas on the second pole piece are stacked to form a second conductive portion; Two pole tabs, the two pole tabs have opposite polarities and are electrically connected to the first pole piece and the second pole piece respectively; Among them, at least one of the empty foil areas in the first conductive portion and / or the second conductive portion is defined as a first empty foil area, and the remaining empty foil areas are second empty foil areas, and the first empty foil area has an extension portion extending along the length direction, and the extension portion can cover at least a portion of the second empty foil area.

2. The multi-electrode battery cell according to claim 1, wherein: The first empty foil area is located on the outside of the battery core in the thickness direction.

3. The multi-electrode battery cell according to claim 2, wherein: The number of the first empty foil areas is two, and the two first empty foil areas are respectively located on two sides of the battery core in the thickness direction.

4. The multi-electrode battery cell according to claim 1, wherein: Along the length direction, both sides of the first empty foil area have the extension parts.

5. The multi-electrode battery cell according to claim 4, wherein: Along the width direction of the pole piece body, the width of the extension portion is smaller than the width of the second empty foil area, and the extension portion is arranged at an end of the first empty foil area relatively far away from the pole piece body; or, along the width direction of the pole piece body, the width of the extension portion is equal to the width of the second empty foil area.

6. The multi-electrode battery cell according to claim 1, wherein: The first conducting portion, the second conducting portion and the two tabs are all located on the same side of the battery core.

7. Multi-electrode battery cells, among which: include: a plurality of first pole pieces; A plurality of second pole pieces, each of the first pole pieces and each of the second pole pieces are alternately stacked to form a battery cell, each of the first pole pieces and each of the second pole pieces has a pole piece body and an empty foil area located on one side of the pole piece body, each of the empty foil areas on each of the first pole pieces is stacked to form a first conductive portion, and each of the empty foil areas on each of the second pole pieces is stacked to form a second conductive portion; Two pole ears, the two pole ears have opposite polarities and are respectively connected to one of the first pole pieces and one of the the second pole piece; Among them, at least one of the empty foil areas in the first conductive portion and / or the second conductive portion is defined as a first empty foil area, and the rest are second empty foil areas, and the first empty foil area has an extension portion extending along the width direction of the electrode body, and the extension portion can cover at least a portion of the second empty foil area.

8. The multi-electrode battery cell according to claim 7, wherein: The first empty foil area is located on the outside of the battery core in the thickness direction.

9. The multi-electrode battery cell according to claim 8, wherein: The number of the first empty foil areas is two, and the two first empty foil areas are respectively located on two sides of the battery core in the thickness direction.

10. The multi-electrode battery cell according to claim 7, wherein: Along the length direction of the pole piece body, the width of the extension portion is smaller than the width of the second empty foil area, and the extension portion is arranged at an end of the first empty foil area relatively far away from the pole piece body; or, along the length direction of the pole piece body, the width of the extension portion is equal to the width of the second empty foil area.

11. Batteries, including: The multi-pole battery cell according to any one of claims 1 to 10.

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