Battery cell and lithium ion battery

Abstract

The utility model is applicable to the technical field of lithium ion batteries, and provides a battery cell and a lithium ion battery. The adhesive tape is adhered to the side edge and / or the bottom of the battery cell body; the adhesive tape is provided with a hollow area penetrating through the adhesive tape. The hollow area is arranged on the adhesive tape, so that the hollow area can form a channel for the battery cell body to absorb free electrolyte while uniform stress and good shaping of the battery cell body are ensured, and the shaping effect of the battery cell and the battery performance can be effectively ensured.

Description

Technical Field

[0001] This application belongs to the field of lithium-ion battery technology, and particularly relates to a battery cell and a lithium-ion battery. Background Technology

[0002] Lithium-ion batteries are generally composed of two or more cells, which are fixed together by wrapping with tape to improve the overall structural stability of the cells. This also prevents the cells from colliding with the casing and causing the electrode sheets to roll over.

[0003] In the conventional manufacturing process, a 10mm-25mm wide adhesive tape is applied to the bottom of the battery cell. However, this tape only covers a small portion of the cell; the majority of the area remains uncovered. Figure 1 As shown. During charging and discharging, changes in the thickness of the electrode sheets and the battery cell directly lead to uneven stress between the coated and uncoated areas at the bottom, easily causing deformation and wrinkles, thus inducing rapid cell failure. The Chinese utility model patents with application numbers CN201210308438.7 and CN200810052296.6 employ a full-coverage method, which can significantly improve the flatness of the battery cell, such as... Figure 2 As shown. However, the tape used in the above-mentioned coating method can affect the cell's absorption of electrolyte, thereby deteriorating the cell's cycle performance and affecting the performance of the lithium-ion battery. Utility Model Content

[0004] This application provides a battery cell that aims to solve the problem that the existing battery cell coating method affects the cell's absorption of electrolyte, thereby deteriorating the cell's cycle performance and affecting the performance of lithium-ion batteries.

[0005] This application provides a battery cell comprising:

[0006] The battery cell itself; and

[0007] Adhesive tape applied to the side and / or bottom of the battery cell body;

[0008] The tape has a perforated area that runs through it.

[0009] Furthermore, the hollowed-out area includes at least one of the following shapes: circle, triangle, quadrilateral, polygon, or irregular shape.

[0010] Furthermore, the equivalent circle diameter of the hollowed-out area is 0.5mm to 10mm.

[0011] Furthermore, the spacing between adjacent hollowed-out areas is 2mm to 20mm.

[0012] Furthermore, the hollowed-out areas are arranged at equal or unequal intervals.

[0013] Furthermore, an adhesive application area is provided at the bottom of the battery cell body, and adhesive tape is applied to the adhesive application area.

[0014] Secondly, this application also provides a lithium-ion battery, comprising:

[0015] Battery casing, with an opening at the top;

[0016] A cover plate that mates with the opening to seal the battery casing; and

[0017] The battery cells, as described above, are located inside the battery casing.

[0018] Furthermore, the cathode material of the lithium-ion battery is at least one of lithium iron phosphate, nickel-cobalt-manganese ternary cathode, nickel-cobalt-aluminum ternary cathode, lithium cobalt oxide, lithium manganese oxide, and lithium nickel-manganese oxide.

[0019] Furthermore, the lithium-ion battery is one or more of cylindrical batteries, pouch batteries, and prismatic batteries.

[0020] The beneficial effects of this application are as follows: The battery cell provided by this application includes a cell body and an adhesive tape attached to the side and / or bottom of the cell body; the adhesive tape has a perforated area penetrating the tape. By setting a perforated area on the adhesive tape, this application ensures that the cell body is evenly stressed and well shaped, while the perforated area forms a channel for the cell body to absorb free electrolyte, effectively ensuring the shaping effect of the cell and the battery performance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the encapsulation structure of a battery cell in the prior art;

[0022] Figure 2 This is a schematic diagram of the encapsulation structure of a battery cell in another embodiment of the prior art;

[0023] Figure 3 This is a schematic diagram of a battery cell embodiment provided in this application, where the hollowed-out area is a square.

[0024] Figure 4 This is a schematic diagram of a battery cell embodiment provided in this application, where the hollowed-out area is a triangle.

[0025] Figure 5 This is a schematic diagram of a battery cell embodiment provided in this application, where the hollowed-out area is circular.

[0026] Figure 6 This is a schematic diagram of the cycle performance of one embodiment of the battery cell provided in this application;

[0027] Figure 7This is a schematic diagram of the battery cell structure of Comparative Example 1, one embodiment of the battery cell provided in this application;

[0028] Figure 8 This is a schematic diagram of the battery cell structure of Comparative Example 2, one embodiment of the battery cell provided in this application.

[0029] Explanation of reference numerals in the attached diagram: 100 - battery cell body, 200 - tape, 210 - hollow area. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0031] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference values ​​and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0036] The battery cell provided in this application includes a cell body and an adhesive tape attached to the sides and / or bottom of the cell body; the adhesive tape has a perforated area extending through it. By creating a perforated area on the adhesive tape, this application ensures that the cell body is evenly stressed and well-shaped, while the perforated area forms a channel for the cell body to absorb free electrolyte, effectively guaranteeing the shaping effect of the cell and the battery performance.

[0037] like Figures 1 to 8 As shown, one embodiment of this application provides a battery cell, comprising:

[0038] Battery cell body 100; and

[0039] Adhesive tape 200 is affixed to the side and / or bottom of the battery cell body 100;

[0040] The tape 200 has a perforated area 210 that runs through the tape 200.

[0041] The cell body 100 is composed of cells assembled by winding. Typically, the cell body 100 consists of at least two cell arrays. For example, several cell units can be arranged in a straight line to form the cell body 100, or the cell units arranged in a straight line can be used as a group of cells, and then several groups of cells can be arranged side by side to form the cell body 100. Further details are omitted.

[0042] The sides and / or bottom of the cell body 100 are designated as adhesive application areas. Preferably, the bottom of the cell body 100 is designated as the adhesive application area. The adhesive application area is used to apply adhesive tape 200 to wrap and fix several individual cell units, thereby improving the overall structural stability of the cell body 100.

[0043] Since the cell body 100 needs to be immersed in the electrolyte to allow the cell body 100 to contact and absorb the electrolyte, a hollow area 210 is provided through the tape 200. This hollow area 210 penetrates the tape 200, meaning that the hollow area 210 can form a channel for the cell body 100 to absorb free electrolyte. The rest of the tape 200 can support and fix the cell body 100. While ensuring that the cell body 100 is evenly stressed and well shaped, the electrolyte circulates and contacts the cell body 100 to react, which can effectively ensure the shaping effect of the cell and the battery performance.

[0044] In some embodiments, the cutout area 210 can be designed in various shapes, such as at least one of a circle, triangle, quadrilateral, polygon, or irregular shape, preferably a circle.

[0045] For example, the cutout area 210 can be designed as a square, such as... Figure 3 As shown.

[0046] As one possible implementation, the hollowed-out area 210 can be designed as a triangle, such as... Figure 4 As shown.

[0047] As another possible implementation, the hollowed-out area 210 can be designed as a circle, such as... Figure 5 As shown.

[0048] For example, taking the 3914895-50Ah square lithium-ion battery as an example, the cycle performance of Example 1, Comparative Example 1, and Comparative Example 2 was experimentally measured as follows: Figure 6 As shown, Figure 6 In the diagram, the square represents Example 1, the circle represents Comparative Example 1, the triangle represents Comparative Example 2, the horizontal axis represents the number of cycles, and the vertical axis represents the capacity retention rate.

[0049] In Example 1, during the assembly of the 3914895-50Ah square lithium-ion battery, a 105mm patterned adhesive tape 200 is affixed to the center of the bottom of the cell body 100. The cutout area 210 of the adhesive tape 200 is a 2mm circle. Figure 5 As shown. The tape 200 not only ensures that the cell body 100 is subjected to uniform force, but the hollow pattern on the tape 200 also provides channels for the cell body 100 to absorb electrolyte, ensuring better cycle performance.

[0050] In Comparative Example 1, during the assembly of the 3914895-50Ah square lithium-ion battery, a 25mm wide adhesive tape 200 was attached to the center of the bottom of the cell body 100, and electrolyte injection and formation were performed according to the standard procedure. After being fully charged at 1C and disassembled, the cell body 100 showed deformation on both sides of the adhesive tape 200, with obvious bending and wrinkles, such as... Figure 7 As shown.

[0051] In Comparative Example 2, during the cell assembly process of the 3914895-50Ah square lithium-ion battery, three 45mm wide adhesive tapes 200 were applied to the center of the bottom of the cell body 100 to ensure complete adhesion. Afterward, electrolyte injection and formation were performed according to standard procedures. Upon disassembly after a full charge at 1C current, the cell body 100 showed good flatness and no obvious deformation. Figure 8 As shown.

[0052] Optionally, the tape 200 has multiple cutout areas 210, which can be arranged in an orderly or disordered manner. For example, the cutout areas 210 can be arranged at equal or unequal intervals, preferably at equal intervals.

[0053] Optionally, the interval between two adjacent cutout areas 210 is 2mm to 20mm. For example, the interval between two adjacent cutout areas 210 can be any value among 2mm, 3mm, 4mm, 5mm, 8mm, 10mm, 12mm, 15mm, 18mm or 2mm to 20mm, without specific limitation.

[0054] In implementation, the interval between two adjacent hollow areas 210 can be the shortest distance between them. For example, taking a circular hollow area 210 as an example, when two circular hollow areas 210 are arranged horizontally, the distance between the intersection of the horizontal line passing through the center of the circular hollow area 210 and the two circles is recorded as the interval between the two hollow areas 210. Of course, in some other embodiments, the interval between two hollow areas 210 can also be determined in other ways. For example, the distance between the centers of the two circular hollow areas 210 can be used as the interval between the two hollow areas 210, or when the hollow area 210 is square or triangular, the distance between the geometric center points of the hollow areas 210 can be used as the interval between the two hollow areas 210. Further details are omitted.

[0055] Furthermore, the area of ​​the hollowed-out regions 210 of different shapes can be converted into the area of ​​an equivalent circle. For example, the diameter of the equivalent circle of the hollowed-out region 210 is 0.5mm to 10mm. For instance, the diameter of the equivalent circle of the hollowed-out region 210 can be any value among 0.5mm, 1mm, 1.5mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or 0.5mm to 10mm, preferably 2mm, without specific limitation. Through the above arrangement, the battery cell body 100 can be effectively supported and fixed while ensuring that the channel formed by the hollowed-out region 210 for the battery cell body 100 to absorb free electrolyte is large enough to ensure battery performance.

[0056] In some embodiments, this application also provides a lithium-ion battery, comprising:

[0057] Battery casing (not shown), with an opening at the top;

[0058] A cover plate (not shown) that mates with the opening to seal the battery casing; and

[0059] The battery cells, as described above, are located inside the battery casing.

[0060] In practice, the battery casing and cover plate form a sealed container, which can be filled with electrolyte, allowing the battery cells inserted into the container to come into contact with and react with the electrolyte.

[0061] In some embodiments, the cathode material of the lithium-ion battery is at least one of lithium iron phosphate, nickel-cobalt-manganese ternary cathode, nickel-cobalt-aluminum ternary cathode, lithium cobalt oxide, lithium manganese oxide, and lithium nickel-manganese oxide, without specific limitation.

[0062] Furthermore, the lithium-ion battery is one or more of cylindrical batteries, pouch batteries, and prismatic batteries.

[0063] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the battery cell in the lithium-ion battery described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments, and will not be repeated here.

[0064] The battery cell provided in this application includes a cell body 100 and an adhesive tape 200 attached to the sides and / or bottom of the cell body 100; the adhesive tape 200 has a perforated area 210 penetrating through the tape 200. By providing the perforated area 210 on the adhesive tape 200, this application ensures that the cell body 100 is evenly stressed and well shaped, while the perforated area 210 forms a channel for the cell body 100 to absorb free electrolyte, effectively ensuring the shaping effect of the cell and the battery performance.

[0065] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized by, The battery cell comprises: a cell body; and a tape attached to the side and / or bottom of the cell body; the tape is provided with a hollowed-out area penetrating through the tape.

2. The battery cell of claim 1, wherein, The hollowed-out area comprises at least one of a circle, a polygon, or an irregular shape.

3. The battery cell of claim 1, wherein, The equivalent circle diameter of the hollowed-out area is 0.5 mm to 10 mm.

4. The battery cell of claim 1, wherein, The spacing distance between adjacent hollowed-out areas is 2 mm to 20 mm.

5. The battery cell of claim 1, wherein, The hollowed-out areas are arranged at equal or unequal distances.

6. The battery cell of claim 1, wherein, The bottom of the cell body is provided with a tape-attached area, and the tape is attached to the tape-attached area.

7. A lithium-ion battery, characterized by The battery cell comprises: a battery shell having an opening at the top; a cover plate matched with the opening for covering the battery shell; and a battery cell as claimed in any one of claims 1 to 6 arranged in the battery shell.

8. The lithium-ion battery of claim 7, wherein, The lithium ion battery is one or more of a cylindrical battery, a soft-pack battery, and a square battery.

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