Aluminum-plastic film and soft-pack battery

Abstract

The utility model belongs to the technical field of aluminum-plastic film structure, and specifically relates to an aluminum-plastic film, comprising a main body and an edge portion connected to each other, wherein the edge portion extends from the main body along the width direction; the thickness of the main body is d 1 , the thickness of the edge portion is d 2 , where d 1 and d 2 Satisfy the relationship: d 1 / d 2 =a%, a=60-99. The utility model can reduce the volume of the aluminum-plastic film by providing a thickness difference between the main body and the edge of the aluminum-plastic film without affecting the safety performance and electrical performance of the soft-pack battery using the aluminum-plastic film. Under the condition of the same specifications of the battery, the volume of the battery cell using the aluminum-plastic film of the utility model is larger, and the energy density of the battery is increased. In addition, the utility model also discloses a soft-pack battery including the above aluminum-plastic film.

Description

Technical Field

[0001] The utility model belongs to the technical field of aluminum-plastic film structures, and in particular relates to an aluminum-plastic film and a soft-pack battery. Background Art

[0002] Nowadays, with the development of modern society and the enhancement of people's environmental awareness, more and more devices choose lithium-ion batteries as power sources, such as mobile phones, laptops, power tools and electric vehicles. In recent years, lithium-ion batteries have gradually extended from the portable electronic product market to the field of high-end electronic products and power batteries, and higher requirements have been put forward for the energy density, cycle life and safety performance of batteries.

[0003] Among them, soft-pack batteries are widely used in 3C, energy storage and power battery fields due to their excellent safety performance, light weight and low internal resistance. Soft-pack batteries use lightweight aluminum-plastic film as the battery shell material, and the battery is sealed by heating and melting the polypropylene layer inside the aluminum-plastic film. Existing battery cells have thickness differences, which are generally thickest at the tabs and thinnest at the edges. The aluminum-plastic film structure is mostly a flat structure with consistent thickness, which increases the battery volume and reduces the volume share of the cell in the battery, thereby reducing the energy density. To this end, it is urgent to propose a new technical solution to solve the above problems. Utility Model Content

[0004] One of the purposes of the utility model is to provide an aluminum-plastic film to address the deficiencies of the prior art. The aluminum-plastic film has a thickness difference between the main body and the edge, thereby reducing the volume of the aluminum-plastic film, increasing the volume proportion of the battery cell in the battery, and thus increasing the energy density of the battery.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An aluminum-plastic film comprises a main body and an edge portion connected to each other, wherein the edge portion extends from the main body along a width direction;

[0007] The thickness of the main body is d1, and the thickness of the edge is d2, wherein d1 and d2 satisfy the relationship: d1 / d2=a%, a=60-99.

[0008] It should be noted that the utility model is applicable to general battery cell structures. Such structures are thicker at the ear positions and thinner at the edges, so that the battery cell is a structure that is thick in the middle and thin on both sides. The structure of the aluminum-plastic film in the utility model corresponds to the battery cell structure, which is a structure that is thin in the middle and thick on both sides. It can reduce the volume fraction of the aluminum-plastic film in the overall soft-pack battery without affecting the safety performance and electrical performance of the soft-pack battery, thereby increasing the energy density of the soft-pack battery.

[0009] As an improvement of the aluminum-plastic film described in the utility model, the width w1 of the main body and the width w2 of the edge portion satisfy the relationship: w2 / w1=b%, b=10-50. Correspondingly, the width of the main body corresponds to the width of the thicker area in the middle of the battery cell, and the width of the edge portion corresponds to the width of the thinner area on both sides of the battery cell.

[0010] As an improvement of the aluminum-plastic film described in the utility model, the main body portion includes a first main body portion and a second main body portion connected to each other, the second main body portion extends from the first main body portion along a height direction, the height direction is perpendicular to the width direction, and the second main body portion is arranged corresponding to the battery cell tab area wrapped by the aluminum-plastic film.

[0011] As an improvement of the aluminum-plastic film of the utility model, the thickness of the first main body portion is greater than the thickness of the second main body portion, which can further reduce the volume of the aluminum-plastic film and thus increase the energy density of the battery.

[0012] As an improvement of the aluminum-plastic film of the utility model, the thickness d3 of the first main body portion and the thickness d4 of the second main body portion satisfy the relationship: d3=2d4.

[0013] As an improvement of the aluminum-plastic film of the utility model, the edge portion includes a first edge portion and a second edge portion connected to each other, and the second edge portion is located at both ends of the first edge portion in the height direction.

[0014] As an improvement of the aluminum-plastic film of the utility model, the first edge portion is arranged corresponding to the first main body portion, and the second edge portion is arranged corresponding to the second main body portion.

[0015] As an improvement of the aluminum-plastic film of the utility model, the thickness d5 of the first edge portion and the thickness d6 of the second edge portion satisfy the relationship: d6 <d5<2d6。

[0016] As an improvement of the aluminum-plastic film of the utility model, the thickness of the second edge portion away from the end of the second main body portion is greater than the thickness of the second edge portion toward the end of the second main body portion.

[0017] The second purpose of the utility model is to provide a soft-pack battery, comprising the aluminum-plastic film as described above.

[0018] As an improvement of the battery described in the utility model, the battery also includes a battery cell and a tab extending therefrom, the battery cell is encapsulated inside the aluminum-plastic film, the tab is encapsulated with the aluminum-plastic film by tab glue, and the tab is at least partially exposed from the aluminum-plastic film.

[0019] The beneficial effect of the utility model is that the aluminum-plastic film of the utility model comprises a main body and an edge part connected to each other, and the edge part extends from the main body in the width direction; the thickness of the main body is d1, and the thickness of the edge part is d2, wherein d1 and d2 satisfy the relationship: d1 / d2=a%, a=60-99. The utility model reduces the thickness of the main body of the aluminum-plastic film, and the volume of the aluminum-plastic film is reduced relative to the flat structure with uniform thickness, thereby reducing the volume share of the aluminum-plastic film in the battery. When the overall size of the soft-pack battery is the same, the soft-pack battery of the utility model is used, and the volume of the battery cell is larger, thereby increasing the energy density of the soft-pack battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0021] Figure 1 It is a schematic diagram of the structure of a battery in an embodiment of the present utility model.

[0022] Figure 2 It is a schematic structural diagram of the top of the battery in an embodiment of the present utility model.

[0023] Figure 3 It is a schematic structural diagram of the bottom of the battery in an embodiment of the present utility model.

[0024] The reference numerals are described as follows:

[0025] 1. Main body; 11. First main body; 12. Second main body;

[0026] 2. edge portion; 21. first edge portion; 22. second edge portion;

[0027] G, height direction; K, width direction; D, growth angle;

[0028] 100, aluminum-plastic film; 200, tab; 300, tab glue. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0031] Reference to "embodiment" in this application means that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0034] In the present application, the soft-pack battery may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0035] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0036] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters, among which energy density is one of the important parameters of the battery.

[0037] For soft-pack batteries, a polymer shell is placed on a liquid battery, and the battery is packaged with an aluminum-plastic film. The inventors found that in soft-pack batteries, the structure of the battery core is usually an irregular structure with a large thickness in the middle and a small thickness at the edge, while the aluminum-plastic film is a flat structure with a uniform thickness. In view of this, in order to improve the energy density of the battery, the embodiment of the present application sets the aluminum-plastic film to a structure with a thin middle and thick edges to reduce the volume of the aluminum-plastic film, which relatively increases the volume ratio of the battery core in the soft-pack battery, thereby increasing the energy density of the soft-pack battery.

[0038] The following is combined with Figure 1-3 The utility model is further described in detail with specific implementation methods, but is not intended to limit the utility model. At the same time, the dotted lines and dash-dotted lines in the drawings are provided for convenience of explanation and do not exist in the actual structure. The shaded parts of the tabs 200 and the tab glue 300 in the drawings are the parts wrapped by the aluminum-plastic film 100 and will not be revealed in the overall structure of the battery.

[0039] like Figure 1As shown, an aluminum-plastic film includes a main body 1 and an edge 2 connected to each other, wherein the edge 2 extends from the main body 1 along a width direction K; the thickness of the main body 1 is d1, and the thickness of the edge 2 is d2, wherein d1 and d2 satisfy the relationship: d1 / d2=a%, and the value of a is 60-65, 65-70, 70-75, 75-80, 80-85 and 85-99.

[0040] In the corresponding soft-pack battery, this embodiment is applicable to a general cell structure, in which the tab position is thicker and the edge position is thinner, the main body 1 corresponds to the thicker middle part of the cell, and the edge 2 corresponds to the thinner edge part of the cell, so that the aluminum-plastic film in this embodiment can reduce the volume of the aluminum-plastic film without affecting the safety performance and electrical performance.

[0041] Specifically, the width w1 of the main body 1 and the width w2 of the edge portion 2 satisfy the relationship: w2 / w1=b%, where the value of b is 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45 and 45-50. It can be understood that there are two edge portions 2, which are located on both sides of the main body 1 in the width direction K. The w2 in the relationship w2 / w1=b% represents the width of the two edge portions 2.

[0042] Specifically, the main body 1 includes a first main body 11 and a second main body 12 connected to each other. The second main body 12 extends from the first main body 11 along a height direction G, and the height direction G is perpendicular to the width direction K. The thickness d3 of the first main body 11 and the thickness d4 of the second main body 12 satisfy the relationship: d3=2d4.

[0043] In this embodiment, two second main bodies 12 are provided, and the two main bodies 12 have the same length in the height direction G and are respectively located at the two ends of the first main body 11 in the height direction G. The upper first main body 11 is arranged corresponding to the pole ear in the soft-pack battery. The battery thickness at the pole ear position is thicker. The thinner second main body 12 is arranged, which can further reduce the volume of the aluminum-plastic film without affecting the safety and electrical performance of the battery.

[0044] It is understandable that in some other embodiments, only one second main body portion 12 may be provided to meet the corresponding tab setting, and the thickness of the second main body portion 12 can be less than that of the first main body portion 11. The specific thickness relationship can be adjusted according to actual conditions.

[0045] Specifically, the edge portion 2 includes a first edge portion 21 and a second edge portion 22 connected to each other, the second edge portion 22 is located at both ends of the first edge portion 21 in the height direction G, the first edge portion 21 is arranged corresponding to the first main body portion 11, and the second edge portion 22 is arranged corresponding to the second main body portion 12. The thickness d5 of the first edge portion 21 and the thickness d6 of the second edge portion 22 satisfy the relationship: d6 <d5<2d6。

[0046] In this embodiment, the second edge portion 22 is respectively arranged on both sides of the first edge portion 21. The arrangement of the second edge portion 21 further reduces the volume of the aluminum-plastic film. It can be understood that in some other embodiments, the second edge portion 22 can be arranged only on one side of the first edge portion 21 close to the pole ear. It can be understood that the second edge portion 22 and the second main body portion 12 do not need to exist at the same time.

[0047] In this embodiment, if Figure 2 and Figure 3 As shown, the thickness of the second edge portion 22 at one end away from the second main body portion 12 is greater than the thickness of the second edge portion 22 toward the second main body portion 12, and the thickness of the first edge portion 21 gradually increases from the first main body portion 11 to the edge of the aluminum-plastic film, forming an increase angle D. The value of the increase angle D is 0-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40° and 40-45°, which can effectively increase the thickness of the first edge portion 21 while achieving a better packaging effect.

[0048] Soft pack battery

[0049] like Figure 1 As shown, a soft-pack battery includes the above-mentioned aluminum-plastic film 100, and also includes a battery cell and a tab 200 led out thereof. The battery cell is encapsulated inside the aluminum-plastic film 100, and the tab 200 is encapsulated with the aluminum-plastic film 100 through a tab glue 300, and the tab 200 is at least partially exposed from the aluminum-plastic film 100.

[0050] Since the thickness of the main body 1 in the aluminum-plastic film 100 is less than the thickness of the edge portion 2, the volume of the aluminum-plastic film 100 is small, and the volume of the battery cell that can be accommodated in the soft-pack battery is increased. Therefore, when the overall size of the soft-pack battery is the same, the volume of the battery cell in the soft-pack battery using this embodiment is larger, thereby increasing the energy density of the soft-pack battery.

[0051] Electrical devices

[0052] An electrical device includes the above-mentioned soft-pack battery, and the battery can be a lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc. Among them, the electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical devices.

[0053] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.

Claims

1. An aluminum-plastic film, characterized in that: It comprises a main body portion (1) and an edge portion (2) which are connected to each other, wherein the edge portion (2) extends from the main body portion (1) along a width direction (K); The thickness of the main body (1) is d1, and the thickness of the edge (2) is d2, wherein d1 and d2 satisfy the relationship: d1 / d2=a%, a=60-99.

2. The aluminum-plastic film according to claim 1, characterized in that: The width w1 of the main body (1) and the width w2 of the edge (2) satisfy the relationship: w2 / w1=b%, b=10-50.

3. The aluminum-plastic film according to claim 1, characterized in that: The main body (1) comprises a first main body (11) and a second main body (12) connected to each other, wherein the second main body (12) extends from the first main body (11) along a height direction (G), and the height direction (G) is perpendicular to the width direction (K).

4. The aluminum-plastic film according to claim 3, characterized in that: The thickness of the first main body portion (11) is greater than the thickness of the second main body portion (12).

5. The aluminum-plastic film according to claim 3, characterized in that: The thickness d3 of the first main body portion (11) and the thickness d4 of the second main body portion (12) satisfy the relationship: d3=2d4.

6. The aluminum-plastic film according to claim 3, characterized in that: The edge portion (2) comprises a first edge portion (21) and a second edge portion (22) which are connected to each other, and the second edge portion (22) is located at both ends of the first edge portion (21) in the height direction (G).

7. The aluminum-plastic film according to claim 6, characterized in that: The first edge portion (21) is arranged corresponding to the first main body portion (11), and the second edge portion (22) is arranged corresponding to the second main body portion (12).

8. The aluminum-plastic film according to claim 6, characterized in that: The thickness d5 of the first edge portion (21) and the thickness d6 of the second edge portion (22) satisfy the relationship: d6 <d5<2d6。 9. The aluminum-plastic film according to claim 6, characterized in that: The thickness of the second edge portion (22) at an end away from the second main body portion (12) is greater than the thickness of the second edge portion (22) at an end facing the second main body portion (12).

10. A soft pack battery, characterized in that: The invention comprises the aluminum-plastic film (100) according to any one of claims 1 to 9, and also comprises a battery cell and a tab (200) extending therefrom, wherein the battery cell is encapsulated inside the aluminum-plastic film (100), the tab (200) is encapsulated with the aluminum-plastic film (100) by tab glue (300), and the tab (200) is at least partially exposed outside the aluminum-plastic film (100).

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