Negative pole piece, battery cell, battery pack and vehicle

Abstract

The utility model discloses a negative pole piece, a battery cell, a battery pack and a vehicle, the negative pole piece comprises a pole piece main body, a tab, an insulating layer and a reinforcing rib, and the pole piece main body is coated with a negative pole coating layer; the tab is arranged independent of the negative electrode coating layer and comprises a tab main body and a tab root part, and the tab main body is connected with the pole piece main body into a whole through the tab root part; the insulating layer covers at least part of the lug root part, and the insulating layer also covers the part, adjacent to the lug root part, of the negative electrode coating layer; and the reinforcing ribs are at least partially arranged on the insulating layer and on the pole piece main body at the position of the root part of the pole lug. Therefore, on one hand, the strength of the lug root part can be enhanced, and the anti-folding capability of the lug on the negative pole piece is improved; and on the other hand, the reinforcing ribs can be prevented from pressing the negative coating layer of the pole piece main body in the processing and forming process, the negative coating layer of the negative pole piece is prevented from powder falling and falling, and the effect of improving the yield of the manufacturing process of the negative pole piece is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of battery-related technology, and in particular relates to a negative electrode sheet, a battery cell, a battery pack, and a vehicle. Background Technology

[0002] To meet the battery capacity requirements of electrical devices, thinner electrode foils are typically used to increase battery energy density. However, with thinner electrode foils, the die-cutting process produces more burrs, and the resulting tabs have weaker support, making them prone to collapse. Furthermore, thinner tabs are susceptible to folding during subsequent winding processes. Folding can lead to an abnormally high discharge / charge power of the cell, and severe folding can affect the cell's cycle interface. Therefore, it is necessary to improve and optimize the tab's resistance to folding before ultrasonic welding.

[0003] Currently, the common practice is to add reinforcing ribs to the tab, and to enhance the tab's resistance to bending by adjusting the position, shape, and pressure of these ribs. However, the placement of the reinforcing ribs on existing negative electrode sheets has its limitations. During processing, the reinforcing ribs cannot be pressed into the negative electrode coating layer. If they are pressed into the coating layer, it will cause the coating to flake off, affecting the performance of the negative electrode sheet and thus weakening its resistance to bending. Utility Model Content

[0004] In view of this, it is necessary to provide a negative electrode sheet, a battery cell, a battery pack, and a vehicle for solving the above-mentioned technical problems.

[0005] A negative electrode sheet, comprising:

[0006] The electrode body is coated with a negative electrode coating layer;

[0007] The tab is set independently of the negative electrode coating layer. The tab includes a tab body and a tab root. The tab body is connected to the electrode sheet body as one unit through the tab root.

[0008] An insulating layer is provided that covers at least a portion of the base of the electrode tab, and the insulating layer also covers a portion of the negative electrode coating layer adjacent to the base of the electrode tab;

[0009] Reinforcing ribs are at least partially disposed on the insulating layer at the location of the root of the tab and on the electrode body.

[0010] It can be understood that by increasing the insulating layer and enabling the reinforcing rib of the negative pole piece to cover the tab root of the tab, on one hand, the strength of the tab root can be enhanced, and the anti-folding capability of the tab on the negative pole piece can be improved; on the other hand, the reinforcing rib can be prevented from being pressed to the negative coating layer of the pole piece main body in the process of molding, and the negative coating layer of the negative pole piece can be prevented from falling off, thereby improving the manufacturing process yield of the negative pole piece.

[0011] In one of the embodiments, the reinforcing rib covers the position of the insulating layer at the tab root.

[0012] It can be understood that the reinforcing rib completely covers the tab root, so that the anti-folding capability of the tab on the negative pole piece can be further improved.

[0013] In one of the embodiments, the insulating layer is configured as a ceramic layer.

[0014] It can be understood that the insulating layer is configured as a ceramic layer, so that the insulating layer on the negative pole piece can share the same material as the ceramic layer on the positive pole piece, thereby facilitating the manufacturing of the negative pole piece.

[0015] In one of the embodiments, the thickness of the insulating layer is set as T1, and the thickness of the pole piece main body is set as T2, wherein 2T1≤T2.

[0016] In one of the embodiments, the insulating layer includes a first insulating part, the first insulating part covers the tab root, and the first insulating part also covers the part of the negative coating layer on the side of the tab root in the width direction of the insulating layer.

[0017] The width of the first insulating part is set as D1, wherein 4mm≤D1≤7mm.

[0018] In one of the embodiments, the insulating layer further includes a second insulating part, the second insulating part is arranged on the negative coating layer and is independent of the tab root.

[0019] The width of the second insulating part is set as D2, wherein 2mm≤D2≤5mm.

[0020] In one of the embodiments, the reinforcing rib includes a first reinforcing part, the first reinforcing part is arranged on the insulating layer.

[0021] The width of the first reinforcing part is set as D3, wherein 1mm≤D3≤3mm.

[0022] The application further provides an electric core including the negative pole piece.

[0023] The application further provides a battery pack comprising the above-mentioned battery cell.

[0024] The application further provides a vehicle comprising the above-mentioned battery pack.

[0025] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0026] The negative pole piece, the battery cell, the battery pack and the vehicle claimed in the application increase the insulating layer and enable the reinforcing rib of the negative pole piece to cover the tab root of the tab, which can enhance the strength of the tab root, improve the anti-folding capacity of the tab on the negative pole piece, avoid the reinforcing rib from pressing the negative coating layer of the main body of the pole piece during the process of molding, prevent the negative coating layer of the negative pole piece from falling off, and improve the production process yield of the negative pole piece. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 The structure of the negative pole piece provided by the application is shown in the figure.

[0029] Reference signs: 100, negative pole piece; 10, main body of pole piece; 11, negative coating layer; 20, tab; 21, main body of tab; 22, tab root; 30, insulating layer; 31, first insulating part; 32, second insulating part; 40, reinforcing rib; 41, first reinforcing part. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only some embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0031] It is to be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. When an element is referred to as being "fixed" to another element, it can be directly fixed to the other element or intervening elements can also be present.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for describing particular embodiments only and is not intended to be limiting of the application. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety for the teachings relevant to the sentence and / or paragraph in which the reference is presented.

[0033] The negative pole piece 100 claimed in the application is specifically applied to the negative pole piece on the battery cell in the power battery.

[0034] As shown in Figure 1 The negative pole piece 100 provided by the application includes a pole piece main body 10, a tab 20, an insulation layer 30, and a reinforcing rib 40. The pole piece main body 10 is coated with a negative coating layer 11. The tab 20 is arranged independently of the negative coating layer 11. The tab 20 includes a tab main body 21 and a tab root 22. The tab main body 21 is connected to the pole piece main body 10 as a whole through the tab root 22. The insulation layer 30 covers at least part of the tab root 22. In addition, the insulation layer 30 also covers the part of the negative coating layer 11 adjacent to the tab root 22. The reinforcing rib 40 is at least partially arranged on the insulation layer 30 at the position of the tab root 22 and on the pole piece main body 10. Here, the insulation layer 30 can completely cover the tab root 22. The reinforcing rib 40 can be pressed and formed on the negative pole piece 100 by using a special tool.

[0035] As can be seen from the above, the negative pole piece 100 of the application can cover the tab root 22 of the tab 20 by increasing the insulation layer 30 and making the reinforcing rib 40 of the negative pole piece 100. In this way, on the one hand, the strength of the tab root 22 can be enhanced, and the anti-folding capacity of the tab 20 on the negative pole piece 100 can be improved. On the other hand, the reinforcing rib 40 can be prevented from being pressed to the negative coating layer 11 of the pole piece main body 10 during the process of forming, so as to prevent the negative coating layer 11 of the negative pole piece 100 from falling off and improve the production process yield of the negative pole piece 100.

[0036] It should be noted that in the manufacturing of the negative electrode sheet 100, first, a copper foil material meeting the size requirements of the negative electrode sheet 100 is selected; then, the negative electrode coating layer 11 is coated on the selected copper foil material corresponding to the part of the sheet body 10; then, the insulating layer 30 is coated at the junction between the blank area of the copper foil material and the negative electrode coating layer 11; then, the blank area of the copper foil material and the corresponding insulating layer 30 are die-cut to obtain the tab 20 of the negative electrode sheet 100; finally, the reinforcing ribs 40 are pressed and formed on the insulating layer 30 at the position of the tab root 22 and the sheet body 10.

[0037] In an embodiment, the insulating layer 30 is configured as a ceramic layer, wherein the material of the ceramic layer can be the same as that of the ceramic layer on the positive electrode sheet in the battery cell, which can facilitate the manufacturing of the negative electrode sheet 100. It can be understood that in other embodiments, the material of the insulating layer 30 in the negative electrode sheet 100 can also be boehmite, which will not be described here.

[0038] In an embodiment, the thickness of the insulating layer 30 is set as T1, and the thickness of the sheet body 10 is set as T2, wherein 2T1≤T2. That is, the thickness of the insulating layer 30 does not exceed half of the thickness of the sheet body 10, so that the added insulating layer 30 on the negative electrode sheet 100 does not affect the overall thickness of the negative electrode sheet 100.

[0039] As shown in FIG. 1, Figure 1 In an embodiment, the insulating layer 30 includes a first insulating part 31, which covers the tab root 22 and covers the part of the negative electrode coating layer 11 on the side of the tab root 22 in the width direction of the insulating layer 30; wherein the width of the first insulating part 31 is set as D1, wherein 4mm≤D1≤7mm. It can be understood that in this embodiment, the width D1 of the first insulating part 31 can be specifically 4mm, 4.5mm, 5.5mm, 6mm, 7mm, etc., which will not be described here.

[0040] As shown in FIG. 1, Figure 1 In an embodiment, the insulating layer 30 further includes a second insulating part 32, which is arranged on the negative electrode coating layer 11 and is independent of the tab root 22; wherein the width of the second insulating part 32 is set as D2, wherein 2mm≤D2≤5mm. It can be understood that in this embodiment, the width D2 of the second insulating part 32 can be specifically 2mm, 2.5mm, 3mm, 4.6mm, 5mm, etc., which will not be described here.

[0041] As shown in FIG. 1, Figure 1As shown, in one embodiment, the reinforcing rib 40 is provided on the insulating layer 30 at the location of the tab root 22. That is, the reinforcing rib 40 in this embodiment can completely cover the tab root 22, which can further improve the anti-bending ability of the tab 20 on the negative electrode sheet 100. Here, the reinforcing rib 40 also covers the tab body 21 of the tab 20.

[0042] like Figure 1 As shown, in this embodiment, the reinforcing ribs 40 are mesh-like, so that the reinforcing ribs 40 in the negative electrode sheet 100 are connected as one, which can further improve the anti-bending ability of the electrode tab 20.

[0043] like Figure 1 As shown, in one embodiment, the reinforcing rib 40 includes a first reinforcing portion 41, which is disposed on the insulating layer 30. The width of the first reinforcing portion 41 is set to D3, where 1mm ≤ D3 ≤ 3mm. It can be understood that the specific value of the width D3 of the first reinforcing portion 41 in this embodiment can be 1mm, 1.5mm, 2mm, 2.6mm, 3mm, etc., which will not be elaborated here. It should be noted that the first reinforcing portion 41 of the reinforcing rib 40 can at least partially cover the portion of the first insulating portion 31 located at the electrode root 22 in the insulating layer 30, and can also simultaneously cover the portion of the first insulating portion 31 located in the negative electrode coating layer 11. This provides a larger range of dimensional flexibility for the subsequent processing of the reinforcing rib 40, thereby facilitating its processing.

[0044] In addition, it should be noted that when the negative electrode 100 of this application is applied to actual production, statistical records show that the folding rate of the negative electrode 100 in the ultrasonic welding process decreased from 0.61% to 0.18%, and the number of folded negative electrode 100 detected by Mylar visual inspection decreased from 10 pcs / day to 0.5 pcs / day. Obviously, the anti-folding effect of the negative electrode 100 of this application is significantly improved.

[0045] This application also provides a battery cell, including the aforementioned negative electrode 100.

[0046] This application also provides a battery pack including the aforementioned battery cells. Here, the battery pack is a power battery.

[0047] This application also provides a vehicle including the battery pack described above.

[0048] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] Those skilled in the art should understand that the above embodiments are only used to illustrate the present application, and are not used as limitation to the present application, and as long as the above embodiments are made within the scope of the present application, the appropriate changes and variations of the above embodiments fall within the scope of the present application.

Claims

1. A negative electrode sheet, characterized in that, The negative electrode plate (100) includes: The electrode body (10) is coated with a negative electrode coating layer (11); The tab (20) is set independently of the negative electrode coating layer (11). The tab (20) includes a tab body (21) and a tab root (22). The tab body (21) is connected to the electrode body (10) as a whole through the tab root (22). An insulating layer (30) is provided that covers at least a portion of the electrode root (22), and the insulating layer (30) is also provided that covers the portion of the negative electrode coating layer (11) adjacent to the electrode root (22); The reinforcing rib (40) is at least partially disposed on the insulating layer (30) at the location of the electrode root (22) and on the electrode body (10).

2. The negative electrode sheet according to claim 1, characterized in that, The reinforcing rib (40) is disposed on the insulating layer (30) at the location of the base (22) of the electrode ear.

3. The negative electrode sheet according to claim 1, characterized in that, The insulating layer (30) is configured as a ceramic layer.

4. The negative electrode sheet according to claim 1, characterized in that, The thickness of the insulating layer (30) is set to T1, and the thickness of the electrode body (10) is set to T2, wherein 2T1≤T2.

5. The negative electrode sheet according to claim 1, characterized in that, The insulating layer (30) includes a first insulating portion (31), which covers the root portion (22) of the electrode tab and also covers the portion of the negative electrode coating layer (11) located on one side of the root portion (22) of the electrode tab in the width direction of the insulating layer (30). The width of the first insulating part (31) is set to D1, wherein 4mm≤D1≤7mm.

6. The negative electrode sheet according to claim 1, characterized in that, The insulating layer (30) further includes a second insulating portion (32), which is disposed on the negative electrode coating layer (11) and is disposed independently of the electrode root portion (22); The width of the second insulating part (32) is set to D2, wherein 2mm≤D2≤5mm.

7. The negative electrode sheet according to claim 1, characterized in that, The reinforcing rib (40) includes a first reinforcing part (41), which is disposed on the insulating layer; The width of the first reinforcing part (41) is set to D3, where 1mm≤D3≤3mm.

8. A battery cell, characterized in that, Includes the negative electrode sheet (100) as described in any one of claims 1 to 7.

9. A battery pack, characterized in that, Includes the battery cell as described in claim 8.

10. A vehicle, characterized in that, Includes the battery pack as described in claim 9.

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