Novel battery cell and battery using same

Abstract

The utility model discloses a novel battery cell, which comprises at least one pole piece group, and the pole piece group comprises a first pole piece, a second pole piece, a third pole piece and a fourth pole piece, the first pole piece is provided with a first tab, the second pole piece is provided with a second tab, the second pole piece comprises two parallel second pole piece parts and a bending part connected with one ends of the two second pole piece parts, and the first pole piece is positioned between the two second pole piece parts and the bending part; and the first diaphragm is arranged between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are completely separated by the first diaphragm. The utility model also discloses a battery using the novel battery cell. According to the scheme, when the pole piece group is produced, the larger second pole piece is folded to cover the first pole piece, namely, the initial state of the second pole piece is larger, so that the die cutting frequency required for manufacturing the second pole piece is reduced compared with that of a traditional small pole piece, and the possibility of causing burrs on the edge of the pole piece is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium - ion batteries, in particular to a novel battery cell and a battery using the battery cell. Background Art

[0002] At present, there are two processes for preparing battery cells, namely the stacking process and the winding process. Among them, the stacking process produces stacked battery cells, and many small electrode sheets need to be die - cut from the electrode sheets. The more die - cutting times, the easier it is to cause burrs on the edges of the electrode sheets. While the winding process produces wound battery cells, and diaphragm wrinkles or electrode sheet material dropping will occur during the winding process, which will affect the cycle life and safety performance of the battery. Summary of the Invention

[0003] In order to overcome the defects in the prior art, the utility model provides a novel battery cell and a battery using the battery cell.

[0004] To achieve the above object, the technical solution adopted by the utility model is: a novel battery cell, including at least one electrode sheet group, and the electrode sheet group includes:

[0005] A first electrode sheet, and the first electrode sheet is provided with a first tab.

[0006] A second electrode sheet, the second electrode sheet is provided with a second tab, the second electrode sheet includes two parallel second electrode sheet parts, and a bending part connected to one ends of the two second electrode sheet parts, and the first electrode sheet is located between the two second electrode sheet parts and the bending part;

[0007] A first separator, the first separator is arranged between the first electrode sheet and the second electrode sheet, and the first separator completely separates the first electrode sheet and the second electrode sheet.

[0008] Through the above technical solution, when producing the electrode sheet group, a larger second electrode sheet is folded into a size covering the first electrode sheet, that is, the initial state of the second electrode sheet is larger. Therefore, the number of die - cutting times required for making the second electrode sheet is less than that of traditional small electrode sheets, thereby reducing the possibility of causing burrs on the edges of the electrode sheets.

[0009] Further, the first electrode sheet is provided with at least two first tabs, and the two first tabs are arranged on the same side of the first electrode sheet. Arranging the tabs on the same side of the electrode sheet facilitates the subsequent connection of each tab.

[0010] Further, the first electrode sheet is folded along a first direction so that the first tabs overlap. Through this solution, the first electrode sheet is also folded from a larger sheet body into the required size, which can also reduce the number of die - cutting times of the first electrode sheet and reduce the possibility of causing burrs on the edges of the electrode sheets.

[0011] Further, the second pole piece portion and the bending portion are perpendicular to each other. That is, the outer edge of the second pole piece is in a right angle state. When assembling the pole piece groups into a battery, the pole piece groups can be closely attached to each other without gaps, and the pole piece groups and the battery housing can also be closely attached to each other without gaps, thus avoiding space waste.

[0012] Further, the pole piece group further includes a second separator, and the second separator is closely attached to the three sides of the second pole piece facing away from the first separator. The pole piece groups can be separated from each other through the second separator.

[0013] Further, the novel battery cell includes at least two of the pole piece groups, and the pole piece groups are stacked.

[0014] Further, all the first pole tabs in the novel battery cell are ultrasonically welded, and all the second pole tabs in the novel battery cell are ultrasonically welded.

[0015] A battery includes the above novel battery cell, a housing for installing the novel battery cell, and a cover for sealing the novel battery cell in the housing. The cover is provided with electrode posts, and the first pole tab and the second pole tab are respectively connected to the electrode posts.

[0016] Further, within the same battery, all the first pole tabs are ultrasonically welded to form a first pole tab group, all the second pole tabs are ultrasonically welded to form a second pole tab group, and the first pole tab group and the second pole tab group are respectively connected to the electrode posts through connecting pieces.

[0017] By means of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0018] In this application, by folding the larger second pole piece to include the first pole piece, the number of die-cutting times required for manufacturing the second pole piece is reduced, thereby reducing the possibility of burrs on the edge of the pole piece;

[0019] In this application, by folding the larger first pole piece into the required size, the number of die-cutting times required for manufacturing the first pole piece is reduced, thereby reducing the possibility of burrs on the edge of the pole piece.

[0020] To make the above and other objects, features and advantages of the present utility model more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic structural diagram of a pole piece group in an embodiment of the present invention;

[0023] Figure 2 It is a schematic structural diagram of two stacked pole piece groups in an embodiment of the present invention;

[0024] Figure 3 It is a schematic structural diagram of the battery cell in an embodiment of the present invention.

[0025] The reference numerals of the above drawings: 1. First pole piece; 11. First pole tab; 2. First separator; 3. Second pole piece; 31. Second pole tab; 4. Second separator; 5. Connecting piece. Detailed implementation manners

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] It should be noted that in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes to distinguish similar objects, and there is no sequence between them, nor can they be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0028] Embodiment: As shown in Figures 1-3 Embodiment 1 discloses a new type of battery cell, including at least one pole piece group, and the pole piece group includes:

[0029] A first pole piece 1, and two first pole tabs 11 are symmetrically arranged on one side of the first pole piece 1. The first pole piece 1 is folded in half along the first direction so that the two first pole tabs 11 overlap. The first direction is the width direction of the first pole piece 1 itself.

[0030] A first separator 2 is disposed outside the first electrode tab 1, and the first separator 2 covers three consecutive sides of the first electrode tab 1. During assembly, one end of the first separator 2 coincides with one end of the first electrode tab 1, and the first separator 2 is sequentially folded inward along the three consecutive sides of the first electrode tab 1. It should be noted that the bending portion of the first separator 2 is a right angle.

[0031] A second electrode tab 3 is disposed outside the first separator 2, and two second tab ears 31 are symmetrically disposed on one side of the second electrode tab 3. The second electrode tab 2 covers three sides of the first separator 2 facing away from the first electrode tab 1. During assembly, one end of the second electrode tab 3 coincides with one end of the first separator 2, and the second electrode tab 3 is sequentially folded inward along the side of the first separator 2, and the bending portion of the second electrode tab 3 is also a right angle. It should be noted that the two second tab ears 31 are symmetric with respect to the first electrode tab 1.

[0032] A second separator 4 is disposed outside the second electrode tab 3, and the second separator 4 covers three consecutive sides of the second electrode tab 3. During assembly, one end of the second separator 4 coincides with one end of the second electrode tab 3, and the second separator 4 is sequentially folded inward along the side of the second electrode tab 3, and the bending portion of the second separator 4 is also a right angle.

[0033] Through the above technical solution, the first electrode tab 1, the first separator 2, the second electrode tab 3, and the second separator 4 are folded and combined into the electrode tab group. Both the first electrode tab 1 and the second electrode tab 3 are formed by folding a larger electrode tab in half. Compared with the traditional lamination process for producing laminated battery cells, which requires multiple die cuttings to produce a large number of small electrode tabs for lamination, it is known that the die cutting process may cause burrs on the edges of the electrode tabs. In this application, a larger electrode tab is folded in half to the required size. The number of die cuttings of the electrode tabs is reduced, thereby reducing the possibility of burrs on the edges of the electrode tabs. Thereby, the yield is improved.

[0034] Optionally, a plurality of first tab ears 11 may be provided on the first electrode tab 1. Among them, the first tab ears 11 are arranged in a counter-supporting manner on one side of the first electrode tab 1. When folding the first electrode tab 1, the center of every two adjacent first tab ears 11 is used as the folding line, so as to ensure that the first tab ears 11 on the folded first electrode tab 1 can overlap. It is convenient to connect the first tab ears 11 subsequently.

[0035] In this application, the bending parts of the first electrode sheet 1, the first separator 2, the second electrode sheet 3, and the second separator 4 are all right angles. When assembling the electrode sheet group composed of the first electrode sheet 1, the first separator 2, the second electrode sheet 3, and the second separator 4 into a battery, the electrode sheet groups can be closely attached to each other without gaps, and the electrode sheet group and the battery housing can also be closely attached to each other without gaps, thus avoiding waste of space. In a wound-type battery cell produced by the traditional winding process, the corners formed after increasing the number of winding turns cause waste of space.

[0036] In a wound-type battery cell produced by the traditional winding process, the separator wrinkles during winding. The separator wrinkles will cause uneven distribution of internal resistance, resulting in local overcharge or over-discharge during the battery cycle, which in turn affects the cycle life and safety performance. And the separator wrinkles often appear at the positions of black spots and lithium deposition, and the black spots and lithium deposition also affect the battery performance. In this application, the first electrode sheet 1, the first separator 2, the second electrode sheet 3, and the second separator 4 remain flat after folding, thus avoiding separator wrinkles. In addition, during the winding process, a certain amount of force needs to be applied to the separator and the electrode sheet. However, in the actual operation process, errors are inevitable. When the tension control is not good, the separator will be over-stretched in the tape running direction, causing the battery cell to be deformed during winding, and then resulting in electrode sheet dropout. Electrode sheet dropout refers to the separation and shedding of the powder coating of the positive electrode sheet or the negative electrode sheet from the foil. The powder after shedding will become inactive and unable to play a role.

[0037] Embodiment 2 discloses a battery, which includes a new type of battery cell made of the above-mentioned electrode sheet group, a housing for installing the new type of battery cell, and a cover for sealing the battery cell in the housing. The cover is provided with electrode posts, and the first tab 1 and the second tab 3 are respectively connected to the electrode posts.

[0038] Among them, the battery includes at least two of the above-mentioned electrode sheet groups, and the electrode sheet groups are stacked. In the same battery, all the first tabs 11 are ultrasonically welded to form a first tab group, all the second tabs 31 are ultrasonically welded to form a second tab group, and the first tab group and the second tab group are respectively connected to the electrode posts through connecting pieces 5.

[0039] In the present utility model, specific embodiments are used to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A new type of battery cell, characterized in that, Comprising at least one electrode plate group, the electrode plate group comprising: A first electrode plate provided with a first tab; A second electrode plate provided with a second tab, the second electrode plate comprising two parallel second electrode plate portions and a bending portion connected to one end of the two second electrode plate portions, the first electrode plate being located between the two second electrode plate portions and the bending portion; A first separator disposed between the first electrode plate and the second electrode plate, the first separator completely separating the first electrode plate and the second electrode plate.

2. The novel battery cell according to claim 1, wherein, The first electrode plate is provided with at least two first tabs, and the two first tabs are disposed on the same side of the first electrode plate.

3. The novel battery cell according to claim 2, wherein, The first electrode plate is folded along a first direction so that the respective first tabs overlap.

4. The novel battery cell according to claim 1, wherein The second electrode plate portion and the bending portion are perpendicular to each other.

5. The novel battery cell according to claim 1, characterized in that, The electrode plate group further comprises a second separator, and the second separator is in close contact with three sides of the second electrode plate facing away from the first separator.

6. The novel battery cell according to claim 1 or 5, characterized in that, The novel battery cell comprises at least two of the electrode plate groups, and the electrode plate groups are stacked.

7. The novel battery cell according to claim 6, wherein, All the first tabs in the novel battery cell are ultrasonically welded, and all the second tabs in the novel battery cell are ultrasonically welded.

8. A battery, characterized in that, Comprising the novel battery cell according to any one of claims 1-7, a housing for mounting the novel battery cell, and a cover for sealing the novel battery cell in the housing, the cover being provided with electrode posts, and the first tab and the second tab are respectively connected to the electrode posts.

9. The battery according to claim 8, characterized in that, In the same battery, all the first tabs are ultrasonically welded to form a first tab group, all the second tabs are ultrasonically welded to form a second tab group, and the first tab group and the second tab group are respectively connected to the electrode posts through connecting pieces.

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