Battery

Abstract

The utility model discloses a battery. The battery provided by the utility model comprises a battery cell and a shell, a storage cavity is formed in the shell, the battery cell is packaged in the storage cavity, the shell comprises a non-thinned part and at least one thinned part, the thinned part is located on the inner wall surface of the storage cavity, the thickness of the thinned part is smaller than that of the non-thinned part, and the density of the thinned part is larger than that of the non-thinned part. According to the battery disclosed by the utility model, the thinning part with smaller thickness is arranged in the shell so as to improve the energy density, meanwhile, the density of the thinning part with smaller thickness is improved, and particles in the thinning part are arranged more tightly due to smaller thickness and larger density, so that the compactness of the thinning part is improved, and the waterproof performance and the corrosion resistance of the thinning part are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery processing technology, and specifically to a battery. Background Technology

[0002] With the development of battery processing technology, how to improve the energy density of batteries is a problem that needs to be solved. Batteries consist of a casing and cells encapsulated inside the casing. In the existing technology, in order to improve the space utilization inside the casing and thus increase the energy density, the side of the casing facing the cell is thinned to increase the space of the storage cavity, thereby increasing the size of the cell and thus increasing the energy density. However, after the inner side of the casing is thinned, the waterproof performance and corrosion resistance of the thinned area are reduced. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery that improves the waterproof and corrosion-resistant properties of the thinned portion.

[0004] A battery according to an embodiment of the present invention includes a battery cell and a casing. The casing has a storage cavity, and the battery cell is encapsulated within the storage cavity. The casing includes a non-thinned portion and at least one thinned portion. The thinned portion is located on the inner wall surface of the storage cavity. The thickness of the thinned portion is less than the thickness of the non-thinned portion, and the density of the thinned portion is greater than the density of the non-thinned portion.

[0005] The battery according to the embodiments of the present invention has at least the following beneficial effects: The battery of the present invention has a thinner part with a smaller thickness inside the shell to improve the energy density. At the same time, the density of the thinner part with a smaller thickness is increased. The smaller thickness and higher density make the arrangement of particles in the thinner part more compact, that is, improve the compactness of the thinner part, so as to improve the waterproof performance and corrosion resistance of the thinner part.

[0006] According to some embodiments of this utility model, the shell material is aluminum-plastic film. Aluminum-plastic film has certain corrosion resistance and barrier properties, and it also has good cold stamping formability, allowing it to be obtained in the required shape and size through stamping processes. This characteristic enables aluminum-plastic film to be better processed into thinner sections.

[0007] According to some embodiments of this utility model, the housing has a first polypropylene layer on one side located within the storage cavity, and the outer peripheral surface of the battery cell is covered with a second polypropylene layer, with the first polypropylene layer and the second polypropylene layer interconnected. The two layers can be thermally fused together by methods such as hot pressing, thus eliminating the need for hot melt adhesive on the outer periphery of the battery cell, thereby reducing the overall size of the battery cell and increasing energy density.

[0008] According to some embodiments of this utility model, the battery includes tabs connected to the battery cell. Along the thickness direction of the battery, the projection of the tabs lies within the thinned portion. The thickness of the portion with tabs may be greater than the thickness of the portion of the battery cell without tabs. Therefore, providing a thinned portion at the corresponding location can further improve the internal space utilization of the battery, thereby increasing the energy density.

[0009] According to some embodiments of this utility model, the inner wall surface of the storage cavity includes a first arc portion, and the thinned portion forms a groove. The two ends of the first arc portion are respectively connected to the groove wall of the groove and the non-thinned portion. The first arc portion can reduce the sharpness of the groove edge formed by the thinned portion, avoid the connection between the thinned portion and the non-thinned portion being too sharp and causing puncture to the battery cell, and improve safety performance.

[0010] According to some embodiments of this utility model, the inner wall surface of the storage cavity includes a top wall, a bottom wall, and a side wall. The top wall and the bottom wall are spaced apart along the thickness direction of the battery cell. The top wall and the bottom wall are connected through the side wall. At least one of the bottom wall and the top wall is provided with the thinning portion. Preferably providing the thinning portion on the bottom wall allows for better control of its size, ensuring that the battery cell is placed precisely at the corresponding position of the thinning portion when placed on the bottom wall. This maximizes the effectiveness of the thinning portion and improves the product quality of the processed battery. Providing the thinning portion on the top wall, also along the thickness direction of the battery cell, can further improve the battery's energy density and the utilization rate of the thinning portion.

[0011] According to some embodiments of this utility model, the inner wall surface of the storage cavity further includes a second arc portion. The side wall is connected to the bottom wall through the second arc portion. The bottom wall is provided with the thinning portion, and the distance between the thinning portion on the bottom wall near the second arc portion and the second arc portion is L1, where 0 < L1 ≤ 2 mm. The second arc portion can also reduce the sharpness at the connection between the side wall and the bottom wall, avoiding phenomena such as the casing puncturing the battery cell. The casing at the corner needs to have sufficient thickness to have sufficient structural strength to prevent deformation, cracking, etc. Therefore, the thinning portion cannot be opened at the location of the second arc portion, nor can it be too far away. Thus, L1 within the above range can take into account both the advantages of energy density and casing strength.

[0012] According to some embodiments of this utility model, the top wall and the bottom wall each have at least one thinning portion, and the battery cell is sandwiched between the thinning portions of the top wall and the bottom wall. The top and bottom walls are distributed along the thickness direction of the battery cell. Providing thinning portions on both the top and bottom walls can further increase the volume of the storage cavity, reduce the space occupied by the casing, and facilitate improved space utilization and energy density.

[0013] According to some embodiments of this utility model, the thickness of the thinned portion is D1, and the thickness of the non-thinned portion is D2, where 0.6 ≤ D1 / D2 < 1. The ratio between the thickness of the thinned portion and the thickness of the non-thinned portion needs to be within a suitable range to balance the dual requirements of energy density and battery structural strength. When D1 / D2 is less than 0.6, it indicates that the thickness of the thinned portion is reduced by more than 40% compared to the thickness of the non-thinned portion. In this case, the thickness of the thinned portion is reduced too much compared to the non-thinned portion, so the battery structural strength at this point may not be guaranteed, and risks such as deformation and breakage may occur during use.

[0014] According to some embodiments of this utility model, 80μm≤D1≤110μm. Besides meeting the thickness ratio requirement with the non-thinned portion, the specific thickness of the thinned portion itself also needs to be limited. Specifically, it can be values ​​such as 80μm, 100μm, or 110μm. When the thickness D1 of the thinned portion is less than 80μm, the thinning effect is not significant, and the improvement in energy density is also not significant, failing to meet the product's requirement for increased energy density. When the thickness D1 of the thinned portion is greater than 110μm, the thickness reduction is too large, which can easily damage the shell structure at the thinned portion.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a schematic diagram of the battery structure in one embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram showing the unfolded casing of the battery in one embodiment of the present invention;

[0019] Figure 3 for Figure 2 Enlarged view of region A in the middle;

[0020] Figure 4 This is a top view of the battery casing unfolded in one embodiment of the present invention.

[0021] Reference numerals: battery 100, cell 101, casing 102, storage cavity 103, thinned portion 104, non-thinned portion 105, first polypropylene layer 106, second polypropylene layer 107, top wall 108, bottom wall 109, side wall 110, first arc portion 301, second arc portion 302, tab 401. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these 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 utility model, and should not be construed as limiting this utility model.

[0023] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0024] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0026] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] refer to Figure 1 and Figure 2According to an embodiment of the present invention, a battery 100 includes a cell 101 and a casing 102. The casing 102 has a storage cavity 103, and the cell 101 is encapsulated within the storage cavity 103. The casing 102 includes a non-thinned portion 105 and at least one thinned portion 104. The thinned portion 104 is located on the inner wall surface of the storage cavity 103. The thickness of the thinned portion 104 is less than the thickness of the non-thinned portion 105, and the density of the thinned portion 104 is greater than the density of the non-thinned portion 105. The battery 100 of the present invention provides a thinned portion 104 with a smaller thickness within the casing 102 to increase energy density. Simultaneously, increasing the density of the thinned portion 104, resulting in a smaller thickness and higher density, allows for a more compact arrangement of particles within the thinned portion 104, thus improving the compactness of the thinned portion 104 and enhancing its waterproof and corrosion-resistant properties.

[0028] It should be noted that, specifically, in some embodiments of this utility model, the thinning portion 104 is processed on the housing 102 by pressure or rolling. For example, when the housing 102 is made of aluminum-plastic film, rolling a certain area of ​​the aluminum-plastic film facing the battery cell 101 will reduce the overall thickness of that area. However, rolling does not cause mass loss, so the density after rolling or pressure is greater, thus forming the thinning portion 104. Since the inner layer material is not removed, the existing waterproof and corrosion-resistant properties are retained, and the improved density further enhances the waterproof and corrosion-resistant properties. Existing methods such as laser thinning or chemical etching remove the inner surface of the housing 102, which not only reduces the thickness but also causes mass loss. Furthermore, when the housing 102 is made of composite materials such as aluminum-plastic film, the inner layer often plays a role in corrosion resistance. Removing the inner layer will reduce the waterproof and corrosion-resistant properties of the thinned area.

[0029] It should be noted that, Figure 3 The shape of the shell 102 in the middle is Figure 2 The shell 102 shown is formed by folding the right side to the left and sealing it. This design is to improve manufacturing efficiency. In some embodiments of this utility model, the shell 102 can also be a split type, that is, the bottom wall 109 and the top wall 108 are separate designs. For example, when the shell 102 is made of aluminum-plastic film, two aluminum-plastic films are used to package a battery cell 101. A portion of the surface of one aluminum-plastic film serves as the bottom wall 109, and a portion of the surface of the other aluminum-plastic film serves as the top wall 108. Similarly, a thinning portion 104 can be processed on the inner wall of the shell 102. When the shell 102 is made of steel, the bottom wall 109 and the top wall 108 are manufactured separately, and then the two are welded together to form the side wall 110 and the storage cavity 103, etc.

[0030] In some embodiments of this utility model, the casing 102 is made of aluminum-plastic film. The aluminum-plastic film is a composite of aluminum foil and plastic film, resulting in a lightweight design. This reduces the overall weight of the battery 100, helping to increase its energy density and facilitating portability and transportation. The aluminum-plastic film has excellent barrier properties, effectively preventing the penetration of substances such as oxygen and moisture. This characteristic protects the battery 100 from the influence of external environments such as moisture and oxygen, maintaining the stability and safety of the battery 100. For solid-state batteries 100, the barrier properties of the aluminum-plastic film also prevent the exchange of substances between the battery 100's interior and the external environment, ensuring the long-term reliability of the battery 100. The aluminum-plastic film has a certain degree of corrosion resistance, maintaining stable performance under different environmental conditions. This is particularly important for the use of the battery 100 in harsh environments, extending its lifespan. The aluminum-plastic film has good cold-stamping formability, allowing it to be processed into the desired shape and size through stamping processes. This characteristic enables the aluminum-plastic film to be better processed into the thinned portion 104.

[0031] It should be noted that the shell 102 can also be a hard shell made of metal such as steel. Rolling or other processes can be performed on a designated area of ​​the hard shell to form a thinned part 104 with a smaller thickness and higher density, which can also enhance the waterproofness and corrosion resistance of the area.

[0032] refer to Figure 1In some embodiments of this utility model, the shell 102 has a first polypropylene layer 106 on one side inside the storage cavity 103, and the outer peripheral surface of the battery cell 101 is covered with a second polypropylene layer 107. The first polypropylene layer 106 and the second polypropylene layer 107 are connected to each other. In some embodiments of this utility model, the shell 102 is made of aluminum-plastic film. Specifically, the aluminum-plastic film consists of an outer nylon layer, a middle aluminum layer, and an inner layer facing the inside of the storage cavity 103. In this embodiment, the inner layer is the first polypropylene layer 106. Polypropylene has good corrosion resistance, high temperature resistance, and mechanical properties, and can withstand the heat and pressure generated by the battery 100 during use and maintain structural stability. The inner layer of the shell 102 is set as the first polypropylene layer 106, and the second polypropylene layer 107 is set on the outer peripheral surface of the battery cell 101. The two are made of the same material and can be thermally fused together by hot pressing or other methods. This eliminates the need to set hot melt adhesive on the outer periphery of the battery cell 101, thereby reducing the overall size of the battery cell 101 and increasing the energy density. Furthermore, since polypropylene material is easy to process and can be made into the required shape and size through various molding processes such as hot pressing and extrusion, it is easier to manufacture the thinned part 104. The polypropylene in the thinned part 104 formed by rolling and pressing has better density, better water resistance and corrosion resistance. In the prior art, the thinning of the shell 102 often involves removing the polypropylene in this area. Therefore, the thinning in the prior art will reduce the performance of the shell 102.

[0033] refer to Figure 4 In some embodiments of this utility model, the battery 100 includes tabs 401 connected to the cell 101. Along the thickness direction of the battery 100, the projection of the tabs 401 is located within the thinning portion 104. The tabs 401 serve as the conductive medium connecting the cell 101 to the external circuit. During manufacturing, the electrodes of each layer in the cell 101 may extend part of the tabs 401, and then be connected together by bonding or thermal fusion to connect to the external circuit. Therefore, the thickness of the portion with tabs 401 may be greater than the thickness of the portion of the cell 101 without tabs 401. Therefore, providing the thinning portion 104 at the corresponding location can further improve the space utilization rate inside the battery 100, thereby increasing the energy density.

[0034] It should be noted that in some embodiments of this utility model, the outer periphery of the battery cell 101 is also provided with hot melt adhesive or wrapped with tape, etc. The thinning part 104 on the inner wall surface of the storage cavity 103 corresponding to these parts can further improve the space utilization and energy density.

[0035] refer to Figure 2 and Figure 3In some embodiments of this utility model, the inner wall surface of the storage cavity 103 includes a first arcuate portion 301, and the thinned portion 104 is formed with a groove. The two ends of the first arcuate portion 301 are respectively connected to the groove wall and the non-thinned portion 105. The first arcuate portion 301 can reduce the sharpness of the groove edge formed by the thinned portion 104, avoiding the connection between the thinned portion 104 and the non-thinned portion 105 being too sharp and causing puncture to the battery cell 101, thus improving safety performance. It should be noted that in some embodiments of this utility model, the thinned portion 104 is processed by roller pressing. Due to the smoothness of the roller, the first arcuate portion 301 can naturally be processed, which is very simple.

[0036] refer to Figure 1 and Figure 2 In some embodiments of this utility model, the inner wall surface of the storage cavity 103 includes a top wall 108, a bottom wall 109, and a side wall 110. The top wall 108 and the bottom wall 109 are spaced apart along the thickness direction of the cell 101, and are connected by the side wall 110. At least one of the bottom wall 109 and the top wall 108 is provided with a thinning portion 104. It should be noted that the bottom wall 109 and the top wall 108 mentioned above refer to... Figure 1 and Figure 2 The state shown, in some embodiments of this utility model, is first in Figure 2 A thinning portion 104 is machined on the casing 102 shown. The battery cell 101 is then placed into the cavity above the bottom wall 109, and the top wall 108 is then placed on top for encapsulation. Therefore, preferentially creating the thinning portion 104 on the bottom wall 109 allows for better control of its size, ensuring that the battery cell 101 is positioned precisely on the bottom wall 109, maximizing the effectiveness of the thinning portion 104 and improving the overall quality of the processed battery 100. It should be noted that in actual use scenarios of the battery 100, the positions of the top wall 108 or bottom wall 109 shown in the figure may not necessarily be exactly as described. Figure 1 The bottom wall 109 refers to the area where the housing 102 is located below the cell 101 during the processing. The thinning portion 104 on the top wall 108 is also opened in the thickness direction of the cell 101, which can also improve the energy density of the battery 100 and the utilization rate of the thinning portion 104.

[0037] refer to Figure 2 and Figure 3In some embodiments of this utility model, the inner wall surface of the storage cavity 103 further includes a second arc portion 302, the side wall 110 is connected to the bottom wall 109 through the second arc portion 302, and the distance between the thinned portion 104 of the bottom wall 109 near the end of the second arc portion 302 and the second arc portion 302 is L1, 0<L1≤2mm. The second arc portion 302 can also reduce the sharpness at the connection between the side wall 110 and the bottom wall 109, avoiding the shell 102 from puncturing the cell 101. The shell 102 at the corner needs to have sufficient thickness to have sufficient structural strength to prevent deformation, cracking, etc. Therefore, the thinning portion 104 cannot be opened at the location of the second arc portion 302, nor can it be too far away. Thus, L1 can take into account both the advantages of energy density and shell 102 strength within the above range. Specifically, L1 can be a value such as 1mm, 1.5mm, 2mm, etc. When the thinning portion 104 is close to the second arc portion 302, the structural strength of the shell 102 at the corner may not be supported, and there may be risks of deformation and cracking during use and installation. When L1 is greater than 2mm, the distance is too large, and the size of the thinning portion 104 will become too small, reducing the space utilization of the storage cavity 103.

[0038] refer to Figure 3 In some embodiments of this utility model, the corners of the outer periphery of the housing 102 are also chamfered. This design can also reduce the sharpness of the corners, avoid adverse effects caused by collisions or scratches during the installation of the battery 100 on external devices, and prevent accidents such as punctures or scratches when staff handle the battery 100.

[0039] refer to Figure 1 In some embodiments of this utility model, the top wall 108 and the bottom wall 109 are each provided with at least one thinning portion 104, and the battery cell 101 is sandwiched between the thinning portion 104 of the top wall 108 and the thinning portion 104 of the bottom wall 109. The top wall 108 and the bottom wall 109 are distributed along the thickness direction of the battery cell 101. Providing thinning portions 104 on both the top wall 108 and the bottom wall 109 can further increase the volume of the storage cavity 103, reduce the space occupied by the housing 102, and facilitate the improvement of space utilization and energy density.

[0040] refer to Figure 2In some embodiments of this utility model, the thickness of the thinned portion 104 is D1, and the thickness of the non-thinned portion 105 is D2, where 0.6 ≤ D1 / D2 < 1. The ratio between the thickness of the thinned portion 104 and the thickness of the non-thinned portion 105 needs to be within a suitable range to balance the dual requirements of energy density and structural strength of the battery 100. When D1 / D2 is less than 0.6, it indicates that the thickness of the thinned portion 104 is reduced by more than 40% compared to the thickness of the non-thinned portion 105. In this case, the thickness of the thinned portion 104 is reduced too much compared to the thickness of the non-thinned portion 105, so the structural strength of the battery 100 at this point may not be guaranteed, and risks such as deformation and breakage may occur during use.

[0041] In some embodiments of this utility model, 80μm≤D1≤110μm. Besides meeting the thickness ratio requirement with the non-thinned portion 105, the thickness of the thinned portion 104 itself also needs to be limited, specifically to values ​​such as 80μm, 100μm, and 110μm. When the thickness D1 of the thinned portion 104 is less than 80μm, the thinning effect of the thinned portion 104 is not significant, and the improvement in energy density is also not significant, failing to meet the product's requirement for increased energy density. When the thickness D1 of the thinned portion 104 is greater than 110μm, the thickness reduction of the thinned portion 104 is too large, which can easily damage the structure of the shell 102 at the thinned portion 104. For example, when the shell 102 is an aluminum-plastic film with an inner layer of polypropylene, it is necessary to maintain the quality of the thinned portion 104 and increase its density while reducing its thickness. A thickness greater than 110μm may excessively pressurize the internal polypropylene, leading to cracking.

[0042] It should be noted that the reference Figure 4 In some embodiments of this utility model, the battery 100 is a square battery 100. When viewed along the thickness direction of the battery 100, the thinned portion 104 is rectangular on the inner wall of the storage cavity 103, which allows for better processing and size control.

[0043] Furthermore, in some embodiments of this utility model, the long side and the wide side of the thinning portion 104 are also limited in size. Specifically, 5mm ≤ long side size ≤ 120mm, and 40mm ≤ wide side size ≤ 100mm. This design can take into account both the need to improve energy density and maintain the structural strength of the shell 102.

[0044] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A battery, characterized in that, include: Battery cell; A housing having a storage cavity inside, the battery cell being encapsulated within the storage cavity, the housing including a non-thinned portion and at least one thinned portion, the thinned portion being located on the inner wall surface of the storage cavity, the thickness of the thinned portion being less than the thickness of the non-thinned portion, and the density of the thinned portion being greater than the density of the non-thinned portion.

2. The battery according to claim 1, characterized in that, The shell material is aluminum-plastic film.

3. The battery according to claim 2, characterized in that, The housing has a first polypropylene layer on one side located inside the storage cavity, and the outer peripheral surface of the battery cell is covered with a second polypropylene layer, with the first polypropylene layer and the second polypropylene layer connected to each other.

4. The battery according to claim 1, characterized in that, The battery includes tabs connected to the battery cell, and the projection of the tabs is located within the thinned portion along the thickness direction of the battery.

5. The battery according to claim 1, characterized in that, The inner wall of the storage cavity includes a first arc portion, and the thinned portion is formed with a groove. The two ends of the first arc portion are respectively connected to the groove wall of the groove and the non-thinned portion.

6. The battery according to claim 1, characterized in that, The inner wall of the storage cavity includes a top wall, a bottom wall, and a side wall. The top wall and the bottom wall are spaced apart along the thickness direction of the battery cell. The top wall and the bottom wall are connected through the side wall. At least one of the bottom wall and the top wall is provided with the thinning portion.

7. The battery according to claim 6, characterized in that, The inner wall of the storage cavity also includes a second arc portion. The side wall is connected to the bottom wall through the second arc portion. The bottom wall is provided with the thinning portion, and the distance between the end of the thinning portion near the second arc portion and the second arc portion is L1, where 0 < L1 ≤ 2 mm.

8. The battery according to claim 6, characterized in that, The top wall and the bottom wall each have at least one thinning portion, and the battery cell is sandwiched between the thinning portion of the top wall and the thinning portion of the bottom wall.

9. The battery according to claim 1, characterized in that, The thickness of the thinned portion is D1, and the thickness of the non-thinned portion is D2, where 0.6 ≤ D1 / D2 < 1.

10. The battery according to claim 9, characterized in that, 80μm≤D1≤110μm.

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