Battery cells and batteries

Abstract

The battery cell (10) and battery include an electrode piece (1), a separator (2), a tab (3) connected to the electrode piece (1), and an insulating support portion (4) installed at the end of the electrode piece (1) to support the tab (3), and the tab (3) extends outward through the insulating support portion (4).

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from Chinese Patent Application No. "202010614979.7" entitled "Battery Cell and Battery" filed by BBD Company Limited on June 30, 2020.

[0002] The present application relates to the field of batteries, and in particular to battery cells and batteries having such cells. [Background technology]

[0003] In the related art, a battery cell has electrode pieces, a separator, and a tab. During the process of connecting the tab to the cover plate of the battery, after the connection between the tab and the cover plate is completed to form the battery, the tab may be bent to different degrees. During the bending process, the tab may be tilted, and the base of the tab may press down on the separator, causing close contact between the positive electrode piece, separator, and negative electrode piece. During use of the battery, the pressed separator may be damaged, causing insulation failure of the separator, and the positive electrode piece may come into contact with the negative electrode piece, potentially causing an internal short circuit in the battery cell and reducing the safety of the battery. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems in the prior art by providing a battery cell in which an insulating support portion supports the tab, reducing the risk of the separator being damaged when the tab pushes down on the separator, and further reducing the risk of a short circuit occurring inside the battery cell, thereby improving the safety of the battery during use.

[0005] The present application further provides a battery.

[0006] The battery cell of the present application includes an electrode piece, a separator, a tab connected to the electrode piece, and an insulating support portion installed at the end of the electrode piece and supporting the tab, the tab extending outward through the insulating support portion.

[0007] In the battery cell of the present application, by installing an insulating support part, in the process of connecting the tab to the battery cover plate, the insulating support part provides support for the tab, preventing the tab from tilting significantly and preventing the tab from pressing against the separator, reducing the risk of separator damage and the risk of short circuits occurring inside the battery cell, thereby improving the safety of the battery when used.

[0008] In some examples herein, the tab includes a tab root portion connected to the end of the electrode piece and a tab head portion remote from the end of the electrode piece, and the insulating support portion supports the tab root portion.

[0009] In some examples herein, the thickness of the insulating support is equal to the thickness of the electrode strip.

[0010] In some examples of the present application, the electrode piece includes a positive electrode piece having the insulating support portion attached to one end thereof, and the free end surface of the insulating support portion extends beyond the end surface of the separator on the same side.

[0011] In some examples herein, the tab includes a positive electrode tab connected to a positive electrode piece that extends outwardly through the insulating support.

[0012] In some examples of the present application, the electrode piece further includes a negative electrode piece having the insulating support portion attached to an end thereof and extending outward through the insulating support portion, and the tab further includes a negative electrode tab connected to the negative electrode piece.

[0013] In some examples herein, the positive and negative tabs are brought out from the same side of the battery cell.

[0014] In some examples herein, the positive and negative tabs are brought out from different sides of the battery cell.

[0015] In some examples of the present application, the height Ht of an insulating support portion supporting a tab connected to a positive electrode piece, the thickness Dt of the insulating support portion located between the separator and the tab connected to the positive electrode piece, the bending angle α of the tab, and the thickness x of the separator satisfy the relationship Ht≧(100 μm+x−Dt) / cosα.

[0016] In some examples of the present application, Ht, Dt, and x further satisfy the relationship 10 mm≧Ht≧2(100 μm+x−Dt).

[0017] In some examples of the present application, the electrode pieces include negative electrode pieces, and the height Ht of the insulating support portion that supports the tab connected to the negative electrode piece satisfies 1 mm≦Ht≦10 mm.

[0018] In some examples herein, the insulating support portion and the end portion of the electrode piece are attached face-to-face.

[0019] In some examples of the present application, the thickness Dt of the insulating support portion located between the separator and the tab satisfies 4 μm≦Dt≦100 μm. A battery according to the present application includes the battery cell described above.

[0020] In some examples of the present application, the thickness x of the separator satisfies the relationship 4 μm≦x≦40 μm.

[0021] In some examples herein, the insulating support is configured as a support of inorganic salt material.

[0022] In some examples of the present application, the inorganic salt material support is a support made of aluminum oxide or aluminum hydroxide or silicon oxide or silicon hydroxide or magnesium oxide or magnesium hydroxide.

[0023] In some examples herein, the insulating support comprises a support of a heat resistant polymeric material.

[0024] In some examples of the present application, the heat-resistant polymeric support is a support made of polyimide film, thermoplastic polyester, or polybutylene terephthalate.

[0025] In some examples herein, the insulating support has a rectangular cross section.

[0026] The battery according to the present application includes the battery cell.

[0027] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present application. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view of a battery cell according to an embodiment of the present application. [Figure 2] FIG. 10 is a schematic diagram showing a case where the tab of the battery cell according to the embodiment of the present application is tilted. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, the embodiments of the present application will be described in detail. Examples of the embodiments are shown in the drawings, and the same or similar reference numerals throughout indicate the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the drawings are merely illustrative and are intended to interpret the present application, but should not be understood as limiting the present application.

[0030] Hereinafter, a battery cell 10 according to an embodiment of the present application will be described with reference to FIGS. 1 and 2, and the battery cell 10 may be installed in a battery.

[0031] As shown in FIGS. 1 and 2 , a battery cell 10 according to an embodiment of the present invention includes an electrode piece 1, a separator 2, an insulating support 4, and a tab 3. The tab 3 is connected to the electrode piece 1, which includes a positive electrode piece 11 and a negative electrode piece 12. The tab 3 includes a positive electrode tab 33 connected to the positive electrode piece 11 and a negative electrode tab 34 connected to the negative electrode piece 12. The insulating support 4 is installed at the end of the electrode piece 1 to support the tab 3, and the tab 3 extends outward through the insulating support 4. The insulating support 4 is installed at the end of the electrode piece 1 connected to the tab 3, i.e., the insulating support 4 is installed at the end of the electrode piece 1 from which the tab 3 is pulled out. Note that the insulating support 4 may be installed at both the end of the positive electrode piece 11 and the end of the negative electrode piece 12, and both the positive electrode tab 33 and the negative electrode tab 34 may extend outward through the insulating support 4.

[0032] As shown in FIG. 1 , insulating supports 4 are provided at the upper ends of the positive electrode pieces 11 and the lower ends of the negative electrode pieces 12. The upper end of the positive electrode tab 33 is installed to extend upward through the insulating support 4, and the lower end of the negative electrode tab 34 is installed to extend downward through the insulating support 4. Specifically, when the positive electrode tab 33 or the negative electrode tab 34 is connected to a battery cover plate, for example, when the positive electrode tab 33 is connected to the battery cover plate, if the tab 3 is bent, the insulating support 4 can support the tab 3. The insulating support 4 continues to support the tab 3 even after the connection between the tab 3 and the cover plate is completed to form the battery. Compared to the prior art, the tab 3 is not significantly tilted and does not press excessively against the separator 2. This reduces the risk of damage to the separator 2 when the battery cell 10 is vibrated or pressed. Direct contact between the positive electrode piece 11 and the negative electrode piece 12 can be prevented, thereby reducing the risk of short circuits inside the battery cell 10 and improving the safety of the battery. FIG. 1 shows a situation in which the positive electrode tab 33 and the negative electrode tab 34 are pulled out from different sides, i.e., the positive electrode tab 33 is pulled out upward and the negative electrode tab 34 is pulled out downward. It should be understood that the positive electrode tab 33 and the negative electrode tab 34 may also be pulled out from the same side, i.e., the positive electrode tab 33 is pulled out upward together with the negative electrode tab 34, or both are pulled out downward. Regardless of how the positive electrode tab 33 and the negative electrode tab 34 are pulled out, an insulating support 4 is installed at the end of the electrode piece 1 from which the tab 3 is pulled out.

[0033] Therefore, by installing the insulating support part 4, in the process of connecting the tab 3 to the cover plate of the battery, the insulating support part 4 provides support to the tab 3, preventing the tab 3 from tilting significantly and preventing the tab 3 from pressing against the separator 2, reducing the risk of the separator 2 being damaged and reducing the risk of a short circuit occurring inside the battery cell 10, thereby improving the safety of the battery when used.

[0034] In some embodiments of the present application, as shown in FIG. 1 , the tab 3 may include a tab root portion 31 connected to the end of the electrode piece 1 and a tab head portion 32 spaced from the end of the electrode piece 1, and the insulating support portion supports the tab root portion 31. The positive electrode tab 33 and the negative electrode tab 34 may each include a tab root portion 31 and a tab head portion 32. Taking the positive electrode tab 33 as an example, as shown in FIG. 1 , the tab root portion 31 is located below the tab head portion 32, is connected to the tab head portion 32, and is connected to the upper end of the positive electrode piece 11. During the process of connecting the positive electrode tab 33 to the cover plate of the battery, the insulating support portion 4 supports the tab root portion 31, preventing the positive electrode tab 33 from being significantly tilted and allowing the bending angle of the positive electrode tab 33 to be appropriate. This prevents the positive electrode tab 33 from excessively pressing against the separator 2 and effectively preventing damage to the separator 2. Furthermore, it prevents direct contact between the positive electrode piece 11 and the negative electrode piece 12, further improving the safety of the battery.

[0035] In some embodiments of the present application, as shown in FIG. 1 , the cross section of the insulating support part 4 is rectangular. A rectangular insulating support part 4 is easily achieved by coating molding during the manufacturing process. It should be understood that the cross section of the insulating support part 4 is not limited to a rectangle and may be other shapes, such as a trapezoid. The thickness of the insulating support part 4 is equal to the thickness of the electrode piece 1. In the positive electrode piece 11, the thickness of the insulating support part 4 is the distance between the left and right surfaces of the insulating support part 4 in the left-right direction in FIG. 1 , and the distance between the left and right surfaces of the insulating support part 4 is equal to the distance between the left and right surfaces of the positive electrode piece 11. In the up-down direction in FIG. 1 , the left surface of the insulating support part 4 and the left surface of the positive electrode piece 11 are located in the same plane, and the right surface of the insulating support part 4 and the right surface of the positive electrode piece 11 are located in the same plane. Similarly, in the negative electrode piece 12, in the left-right direction in FIG. 1 , the thickness of the insulating support part 4 is the distance between the left and right surfaces of the insulating support part 4, and the distance between the left and right surfaces of the insulating support part 4 is equal to the distance between the left and right surfaces of the negative electrode piece 12. In the up-down direction in FIG. 1 , the left surface of the insulating support part 4 and the left surface of the negative electrode piece 12 are located in the same plane, and the right surface of the insulating support part 4 and the right surface of the negative electrode piece 12 are also located in the same plane. This configuration allows the insulating support part 4 to better support the positive electrode tab 33 and the negative electrode tab 34, ensures that the bending angles of the positive electrode tab 33 and the negative electrode tab 34 are more appropriate, and better prevents the positive electrode tab 33 and the negative electrode tab 34 from crushing the separator 2. Furthermore, it prevents contact between the positive electrode tab 33 and the negative electrode piece 12 and between the negative electrode tab 34 and the positive electrode piece 11, thereby better preventing the risk of a short circuit in the battery cell 10.

[0036] 1 , an insulating support part 4 is provided at one end of the positive electrode piece 11, and the free end face of the insulating support part 4 extends beyond the end face of the separator 2 on the same side. The insulating support part 4 is provided at the upper end of the positive electrode piece 11, and the upper end face of the insulating support part 4 extends beyond the upper end face of the separator 2. When the positive electrode tab 33 is bent, this configuration allows the positive electrode tab 33 and the separator 2 to be separated, preventing the positive electrode tab 33 from pressing against the separator 2. This further prevents the separator 2 from being damaged and ensures the insulating performance of the separator 2.

[0037] In some embodiments of the present application, as shown in FIG. 1 , the height Ht of the insulating support portion 4 supporting the tab 3 (i.e., the positive electrode tab 33) connected to the positive electrode piece 11, the thickness Dt of the insulating support portion 4, the bending angle α of the tab 3, and the thickness x of the separator 2 satisfy the relational expression Ht≧(100 μm+x−Dt) / cosα. The height direction of the insulating support part 4 is the vertical direction in FIG. 1, the thickness direction of the insulating support part 4 is the horizontal direction in FIG. 1, and the thickness x of the separator 2 satisfies the relational expression 4 μm≦x≦40 μm. By configuring in this manner, after the positive electrode tab 33 is bent, the bending angle of the positive electrode tab 33 can be made appropriate, which further prevents the tab 3 from pressing against the separator 2. This further reduces the risk of the separator 2 being damaged when the battery cell 10 is vibrated or pressed, and further prevents direct contact between the positive electrode piece 11 and the negative electrode piece 12. This further reduces the risk of a short circuit occurring inside the battery cell 10, and further improves the safety of the battery.

[0038] In some embodiments of the present application, Ht, Dt, and x further satisfy the relationship 10 mm ≥ Ht ≥ 2 (100 μm + x - Dt), which allows for a more appropriate bending angle of the positive electrode tab 33, further preventing the tab 3 from pressing against the separator 2, further reducing the risk of separator 2 being damaged, and preventing direct contact between the positive electrode piece 11 and the negative electrode piece 12, further reducing the risk of short circuits occurring inside the battery cell 10 and improving battery safety. Designing the relationship for the height of the insulating support 4 not only provides support for the tab, but also ensures that the insulating support is present at the base of the tab, preventing short circuits and providing better insulation.

[0039] In some embodiments of the present application, as shown in FIG. 1, the height Ht of the insulating support part 4 supporting the tab 3 (negative electrode tab 34) connected to the negative electrode piece 12 satisfies the relationship 1 mm≦Ht≦10 mm, and the height direction of the insulating support part 4 is the vertical direction in FIG. 1. By configuring in this manner, it is possible to ensure that the end of the negative electrode piece 12 has a certain structural strength, and it is possible to ensure that the positive electrode piece 11 and the negative electrode piece 12 do not tilt when the tab 3 is bent, so that the state of the tab 3 when it is pulled out can be guaranteed, and wear of the separator 2 can be avoided, thereby ensuring insulation between the positive electrode piece 11 and the negative electrode piece 12.

[0040] 1, the thickness Dt of the insulating support part 4 satisfies the relationship 4 μm≦Dt≦100 μm. The thickness design of the insulating support part 4 can effectively support the tab 3, and prevent short circuits caused by tilting and pressing the tab.

[0041] In some embodiments of the present application, the insulating support part 4 and the end of the electrode piece 1 are attached face-to-face. As shown in FIG. 1, the insulating support part 4 and the upper end of the positive electrode piece 11 are attached face-to-face, and the insulating support part 4 and the lower end of the negative electrode piece 12 are attached face-to-face. This configuration allows the insulating support part 4 to be securely attached to the end of the electrode piece 1 and can firmly support the tab 3, making the arrangement of the insulating support part 4 more rational.

[0042] In some embodiments of the present application, the insulating support member 4 may be made of an inorganic salt material or a heat-resistant polymer material. When the insulating support member 4 is made of an inorganic salt material, the insulating support member 4 may be made of aluminum oxide, aluminum hydroxide, silicon oxide, silicon hydroxide, magnesium oxide, or magnesium hydroxide. Alternatively, the insulating support member 4 may be made of a salt of nitrogen, sulfur, or phosphorus. When the insulating support member 4 is made of a heat-resistant polymer material, the insulating support member 4 may be made of aramid and a heat-resistant polymer material, such as PI (Polyimide Film), PET (Polyethylene terephthalate), or PBT (Polybutylene terephthalate). This configuration can prevent thermal deformation of the insulating support member 4, ensure the structural strength of the insulating support member 4, and enable the insulating support member 4 to reliably support the tab 3, thereby ensuring the operational reliability of the battery cell 10.

[0043] The battery according to the embodiment of the present application includes the battery cell 10 according to the above embodiment. When the battery cell 10 is installed in the battery and the tab 3 is connected to the cover plate of the battery, the insulating support part 4 supports the tab 3, preventing the tab 3 from tilting too much and preventing the tab 3 from pressing against the separator 2. This reduces the risk of the separator 2 being damaged and the risk of a short circuit occurring inside the battery cell 10, thereby improving the safety of the battery when used.

[0044] In the description herein, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "particular examples," or "some examples" mean that the specific features, structures, materials, or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the description herein, the exemplary use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined as appropriate in any one or more embodiments or examples.

[0045] Although the embodiments of the present application have been illustrated and described, as will be understood by those skilled in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is limited by the claims and their equivalents.

Claims

1. an electrode piece, a separator, and a tab connected to the electrode piece; an insulating support portion disposed at an end of the electrode piece and supporting the tab, the tab extending outward through the insulating support portion; The insulating support portion and the end portion of the electrode piece are attached face to face, the tab includes a tab root portion connected to an end of the electrode piece and a tab head portion spaced apart from the end of the electrode piece, the insulating support portion supporting the tab root portion; The electrode piece includes a positive electrode piece having the insulating support part installed at one end thereof, In the tab connected to the positive electrode piece, the tab head is bent relative to the tab base, and when the angle formed by the tab head near the boundary between the tab head and the tab base and the direction perpendicular to the tab base is defined as a tab bending angle α (0<α<90°), a height Ht of an insulating support portion that supports the tab connected to the positive electrode piece, a thickness Dt of the insulating support portion that is located between the separator and the tab connected to the positive electrode piece, a bending angle α of the tab, and a thickness x of the separator satisfy the relational expression Ht≧(100 μm+x−Dt) / cos α.

2. The battery cell according to claim 1 , wherein the thickness of the insulating support portion is equal to the thickness of the electrode piece.

3. A battery cell as described in claim 1, characterized in that the free end face of the insulating support part, at one end of which the positive electrode piece is installed, extends beyond the end face on the same side of the separator.

4. 2. The battery cell according to claim 1, wherein a height Ht of an insulating support portion supporting the tab connected to the positive electrode piece, a thickness Dt of the insulating support portion located between the separator and the tab connected to the positive electrode piece, and a thickness x of the separator satisfy the relationship 10 mm ≧ Ht ≧ 2 (100 μm + x − Dt).

5. 2. The battery cell according to claim 1, wherein the electrode pieces include negative electrode pieces, and a height Ht of an insulating support portion that supports a tab connected to the negative electrode piece satisfies 1 mm≦Ht≦10 mm.

6. The battery cell according to claim 1 , wherein the thickness Dt of the insulating support portion located between the separator and the tab satisfies 4 μm≦Dt≦100 μm.

7. A battery comprising the battery cell according to any one of claims 1 to 6.

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