An aluminum-plastic film, a case, and a battery

Abstract

The utility model relates to a battery field especially relates to an aluminum plastic film, shell and battery, including first composite layer, aluminum foil matrix layer and second composite layer, along the length direction of aluminum plastic film, the thickness of center area is greater than the thickness of rim area, transition area thickness decreases from center area to rim area direction, first composite layer and second composite layer cover opposite sides of aluminum foil matrix layer respectively, the side of first composite layer away from aluminum foil matrix layer is equipped as plane, the side of second composite layer away from aluminum foil matrix layer is equipped as plane, the part of aluminum plastic film corresponding to center area is used to form the bottom of battery shell at least partially, the part of aluminum plastic film corresponding to rim area is used to form the top seal portion of battery shell at least partially, the utility model discloses the aluminum foil matrix layer is closer to the rim of aluminum plastic film, and its thickness is thinner, after aluminum plastic film is manufactured as battery shell, the weak area of battery shell is formed to the thinner area of aluminum foil matrix layer, and it is convenient for gas to escape from weak area, reduces the occurrence of explosion phenomenon.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, and in particular relates to an aluminum-plastic film, a casing and a battery. Background Technology

[0002] The battery casing of lithium-ion pouch batteries is usually made of aluminum-plastic composite film, which is formed by stamping aluminum-plastic composite film to form a membrane casing with an inner cavity. The battery cell is placed inside the membrane casing to achieve the encapsulation of the battery cell.

[0003] Lithium-ion pouch batteries may bulge during cycling, especially under high-rate and fast-charging conditions. Increased internal pressure in the battery casing can cause bulging, and the top seal of the existing battery casing is difficult to open in time to release pressure, resulting in reduced battery safety performance. Summary of the Invention

[0004] The technical problem to be solved by this utility model is: to address the issue that the top seal of the existing battery casing is difficult to open in time for pressure relief, which leads to a reduction in the safety performance of the battery, and to provide an aluminum-plastic film, casing and battery.

[0005] To address the aforementioned problems, one embodiment of this utility model provides an aluminum-plastic film, comprising a first composite layer, an aluminum foil substrate layer, and a second composite layer; Along the length of the aluminum-plastic film, the aluminum foil substrate layer is divided into a central region, a transition region, and an edge region from its center to one side edge; the thickness of the central region is greater than the thickness of the edge region; the thickness of the transition region decreases from the central region to the edge region. The first composite layer and the second composite layer respectively cover opposite sides of the aluminum foil substrate layer; The side of the first composite layer facing away from the aluminum foil substrate layer is set as a plane, and the side of the second composite layer facing away from the aluminum foil substrate layer is set as a plane; The portion of the aluminum-plastic film corresponding to the central region is at least partially used to form the bottom of the battery casing; the portion of the aluminum-plastic film corresponding to the edge region is at least partially used to form the top seal of the battery casing.

[0006] Optionally, along the length of the aluminum-plastic film, one side of the aluminum foil substrate layer gradually approaches the other side of the aluminum foil substrate layer from the center outwards; or... Along the length of the aluminum-plastic film, the two sides of the aluminum foil substrate layer gradually move towards the other side of the aluminum foil substrate layer from the middle to the outer edge.

[0007] Optionally, the first composite layer includes a first anti-corrosion layer, and the second composite layer includes a second anti-corrosion layer; The first anti-corrosion layer and the second anti-corrosion layer respectively cover opposite sides of the aluminum foil substrate layer; the side of the first anti-corrosion layer away from the aluminum foil is set as a plane, and the side of the second anti-corrosion layer away from the aluminum foil substrate layer is set as a plane.

[0008] Optionally, the first composite layer further includes a first adhesive layer and a sealing layer disposed sequentially on the first anti-corrosion layer, and the second composite layer further includes a second adhesive layer and a substrate layer disposed sequentially on the second anti-corrosion layer; The sealing layer is used to form the inner side of the battery casing; Along the length of the aluminum-plastic film, the sum of the thicknesses of the first adhesive layer and the sealing layer is constant; Along the length of the aluminum-plastic film, the sum of the thicknesses of the second adhesive layer and the substrate layer is constant.

[0009] Optionally, the first composite layer includes a first anti-corrosion layer, a first adhesive layer and a sealing layer arranged in sequence, and the second composite layer includes a second anti-corrosion layer, a second adhesive layer and a substrate layer arranged in sequence. The first anti-corrosion layer and the second anti-corrosion layer respectively cover the opposite sides of the aluminum foil substrate layer; Along the length of the aluminum-plastic film: the thickness of the first anti-corrosion layer is constant, and the thickness of the second anti-corrosion layer is constant; the side of the first adhesive layer facing away from the first anti-corrosion layer is planar, and the side of the second adhesive layer facing away from the second anti-corrosion layer is planar; along the length of the aluminum-plastic film: the thickness of the sealing layer is constant, and the thickness of the substrate layer is constant; or... Along the length of the aluminum-plastic film: the thickness of the first anti-corrosion layer is constant, the thickness of the second anti-corrosion layer is constant, the thickness of the first adhesive layer is constant, and the thickness of the second adhesive layer is constant; the side of the sealing layer away from the first adhesive layer is set as a plane, and the side of the substrate layer away from the second adhesive layer is set as a plane.

[0010] Optionally, along the length of the aluminum-plastic film, the thickness of the aluminum foil substrate layer gradually decreases from the center to the outer edge; or, The thickness of the central region is constant, and the thickness of the edge region is constant; or... The thickness of the central region is constant, while the thickness of the edge region gradually decreases in the direction away from the transition region.

[0011] Optionally, at least one surface of the transition zone is an inclined surface or a curved surface; The two sides of the edge region are planes, or at least one side of the edge region is an inclined plane or a curved surface.

[0012] Optionally, the aluminum foil substrate layer has a first surface and a second surface opposite to each other along its thickness direction; Along the thickness direction of the aluminum-plastic film, the first surface protrudes towards the first anti-corrosion layer; the vertex of the first surface is located at the center line of the first surface; the side surface of the first composite layer facing the first surface is adapted to the shape of the first surface; Along the thickness direction of the aluminum-plastic film, the second surface protrudes toward the second anti-corrosion layer; the vertex of the second surface is located at the center line of the second surface; the side surface of the second anti-corrosion layer facing the second surface is adapted to the shape of the second surface.

[0013] Optionally, both the first surface and the second surface are curved surfaces, and along the length of the aluminum-plastic film, the first surface and the second surface are close to each other away from the center of the aluminum-plastic film.

[0014] On the other hand, the present invention also provides a battery casing, which is formed by folding the above-mentioned aluminum-plastic film along a preset axis, wherein the aluminum-plastic film is punched along at least one side of the preset axis to form a first receiving groove, and the first receiving groove is used to receive the battery cell. The side of the first composite layer that is away from the aluminum foil substrate layer is located on the side of the aluminum-plastic film closer to the battery cell; The portion of the aluminum-plastic film corresponding to the central region at least partially forms the bottom of the battery casing; the portion of the aluminum-plastic film corresponding to the edge region at least partially forms the top seal of the battery casing.

[0015] Optionally, the portion of the aluminum-plastic film corresponding to the central area forms the bottom of the battery casing, or forms the bottom of the battery casing and the transition portion between the bottom of the casing and the side of the casing; The aluminum-plastic film, corresponding to the edge area, forms the top seal of the battery casing, or forms the top seal and a portion of the top edge of the battery casing.

[0016] Furthermore, this utility model also provides a battery, including the aforementioned casing.

[0017] This utility model provides an aluminum-plastic film, a casing, and a battery. The aluminum foil substrate layer has an uneven thickness, with the thickness decreasing closer to the edge of the aluminum-plastic film. When the aluminum-plastic film is stamped and manufactured into a battery casing, the thinner areas of the aluminum-plastic film form weak areas in the battery casing. When the battery cell expands, the gas bursts through the weak areas of the battery casing, causing the gas to escape and thus reducing gas accumulation and minimizing the occurrence of explosions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the layer structure of the aluminum-plastic film provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the layer structure of the aluminum-plastic film provided in one embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the thickness variation of the aluminum foil substrate layer provided in one embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the thickness variation of the aluminum foil substrate layer in one embodiment of the present invention. Figure 5 This is a schematic diagram of the structure of the aluminum-plastic film after double-sided perforation in one embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the aluminum-plastic film after a single-sided perforation in one embodiment of the present invention; Figure 7 This is a schematic diagram of the aluminum-plastic film after it has been perforated on both sides and folded in half, according to one embodiment of the present invention.

[0020] The reference numerals in the accompanying drawings are as follows: 1. Aluminum foil substrate layer; 11. Central area; 12. Transition area; 13. Edge area; 2. First composite layer; 21. First anti-corrosion layer; 22. First adhesive layer; 23. Sealing layer; 3. Second composite layer; 31. Second anti-corrosion layer; 32. Second adhesive layer; 33. Substrate layer; 4. Shell; 41. First receiving groove. Detailed Implementation

[0021] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and 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, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] like Figures 1 to 7 As shown, one embodiment of this utility model provides an aluminum-plastic film, specifically referring to... Figure 1 and Figure 2 The aluminum-plastic film includes a first composite layer 2, an aluminum foil substrate layer 1, and a second composite layer 3. Along the length of the aluminum-plastic film, the aluminum foil substrate layer 1 is divided into a central region 11, a transition region 12, and an edge region 13 from its center to one side edge. The thickness of the central region 11 is greater than the thickness of the edge region 13. The thickness of the transition region 12 decreases from the central region 11 to the edge region 13. The first composite layer 2 and the second composite layer 3 respectively cover opposite sides of the aluminum foil substrate layer 1. The side of the first composite layer 2 away from the aluminum foil substrate layer 1 is planar, and the side of the second composite layer 3 away from the aluminum foil substrate layer 1 is planar. The portion of the aluminum-plastic film corresponding to the central region 11 is at least partially used to form the bottom of the battery casing 4. The portion of the aluminum-plastic film corresponding to the edge region 13 is at least partially used to form the top seal of the battery casing 4.

[0025] In existing technologies, the thickness of the aluminum foil substrate layer is constant along the length of the aluminum-plastic film, resulting in a similar thickness at every point of the casing formed after stamping. With this type of aluminum-plastic film, existing battery casings lack a venting point when the battery cell expands, leading to gas accumulation and a high risk of explosion. Furthermore, during battery cycling, the casing is repeatedly squeezed and stretched as the cell expands, causing corner cracks and other problems. This allows moisture to enter the battery, corroding electrode materials and causing issues such as excessive battery thickness, increased internal resistance, gas buildup, and leakage, ultimately leading to battery cycle failure and even safety issues like combustion and explosion. In this embodiment, the thickness of the aluminum foil substrate layer 1 is uneven, thinning closer to the edge of the aluminum-plastic film. When the aluminum-plastic film is stamped and manufactured into the battery casing 4, the thinner areas form weak points in the battery casing 4 (e.g., the top seal). When the battery cell expands, the gas escapes through these weak points, cracking the battery casing 4 and reducing gas accumulation, thus minimizing the risk of explosion. The aluminum-plastic film corresponding to the central area 11 is at least partially used to form the bottom of the battery casing 4, thereby strengthening the bottom of the battery casing 4 and preventing the corner of the bottom edge of the battery cell from directly squeezing the bottom rounded corner of the battery casing 4, which would cause the casing 4 to crack. The thickness of the aluminum foil layer is configured according to the load size to optimize the load margin of each area of ​​the aluminum-plastic film, ensuring the reliability and safety of the battery.

[0026] In addition, the overall amount of aluminum foil substrate layer 1 used is reduced due to the thinning of the thickness of both sides of the aluminum foil substrate layer 1, thereby increasing the energy density of the battery cell.

[0027] Reference Figure 1 In one embodiment, along the length of the aluminum-plastic film, both sides of the aluminum foil substrate layer 1 gradually converge towards the other side of the aluminum foil substrate layer 1 from the middle to the outer edge. In other words, both sides of the aluminum-plastic film are curved surfaces, and the thickness of the aluminum-plastic film gradually decreases from the middle to the outer edge.

[0028] Reference Figure 2 In one embodiment, along the length of the aluminum-plastic film, one side of the aluminum foil substrate layer 1 gradually approaches the other side of the aluminum foil substrate layer 1 from the center outwards. In other words, one surface of the aluminum-plastic film is flat, and the other surface is curved, and the thickness of the aluminum-plastic film gradually decreases from the center to the outer edge.

[0029] In one embodiment, the first composite layer 2 includes a first anti-corrosion layer 21, and the second composite layer 3 includes a second anti-corrosion layer 31; the first anti-corrosion layer 21 and the second anti-corrosion layer 31 respectively cover opposite sides of the aluminum foil substrate layer 1; the side of the first anti-corrosion layer 21 away from the aluminum foil is planar, and the side of the second anti-corrosion layer 31 away from the aluminum foil substrate layer 1 is planar.

[0030] In this embodiment, along the length of the aluminum-plastic film, since the thickness of the aluminum foil substrate layer 1 gradually decreases from its center to its edge, the thicknesses of the first anti-corrosion layer 21 and the second anti-corrosion layer 31 on both sides of the thickness of the aluminum foil substrate layer 1 are adaptively varied. This ensures that the overall thickness of the aluminum foil substrate layer 1, the first anti-corrosion layer 21, and the second anti-corrosion layer 31 remains constant along the length of the aluminum-plastic film, resulting in a consistent overall thickness. If the thicknesses of the first anti-corrosion layer 21 and the second anti-corrosion layer 31 are not adaptively varied, the overall thickness of the aluminum foil substrate layer 1, the first anti-corrosion layer 21, and the second anti-corrosion layer 31 may also be thinner in the middle and thinner at the edges, affecting subsequent stamping and other processes.

[0031] More specifically, the first composite layer 2 further includes a first adhesive layer 22 and a sealing layer 23 sequentially disposed on the first anti-corrosion layer 21, with the sealing layer 23 and the first anti-corrosion layer 21 fixed by the first adhesive layer 22. The second composite layer 3 further includes a second adhesive layer 32 and a substrate layer 33 sequentially disposed on the second anti-corrosion layer 31, with the substrate layer 33 and the second anti-corrosion layer 31 fixed by the second adhesive layer 32. The sealing layer 23 is used to form the inner side of the battery casing 4; the sum of the thicknesses of the first adhesive layer 22 and the sealing layer 23 is constant along the length direction of the aluminum-plastic film; the sum of the thicknesses of the second adhesive layer 32 and the substrate layer 33 is constant along the length direction of the aluminum-plastic film.

[0032] In this embodiment, to protect the aluminum foil substrate layer 1, a first anti-corrosion layer 21 and a second anti-corrosion layer 31 are respectively used to protect both sides of the aluminum foil substrate layer 1. The inner wall of the battery casing 4 is then sealed by a sealing layer 23. The substrate layer 33 serves as the outer wall of the battery casing 4, so that the first anti-corrosion layer 21, the second anti-corrosion layer 31, and the aluminum foil substrate layer 1 are all located inside the aluminum-plastic film. Only in abnormal situations will a cracking force be applied to the aluminum foil substrate layer 1. Under normal conditions, the first anti-corrosion layer 21, the second anti-corrosion layer 31, and the aluminum foil substrate layer 1 are all protected, reducing external damage to the three.

[0033] In other embodiments, the first composite layer 2 includes a first anti-corrosion layer 21, a first adhesive layer 22, and a sealing layer 23 arranged sequentially; the second composite layer 3 includes a second anti-corrosion layer 31, a second adhesive layer 32, and a substrate layer 33 arranged sequentially; the first anti-corrosion layer 21 and the second anti-corrosion layer 31 respectively cover opposite sides of the aluminum foil substrate layer 1; along the length direction of the aluminum-plastic film: the thickness of the first anti-corrosion layer 21 is constant, and the thickness of the second anti-corrosion layer 31 is constant; the side of the first adhesive layer 22 away from the first anti-corrosion layer 21 is planar, and the side of the second adhesive layer 32 away from the second anti-corrosion layer 31 is planar; along the length direction of the aluminum-plastic film: the thickness of the sealing layer 23 is constant, and the thickness of the substrate layer 33 is constant. Alternatively, along the length of the aluminum-plastic film: the thickness of the first anti-corrosion layer 21 is constant, the thickness of the second anti-corrosion layer 31 is constant, the thickness of the first adhesive layer 22 is constant, and the thickness of the second adhesive layer 32 is constant; the side of the sealing layer 23 facing away from the first adhesive layer 22 is planar, and the side of the substrate layer 33 facing away from the second adhesive layer 32 is planar. The same principle applies to the layer structure arrangement of the aluminum-plastic film described above, and will not be repeated here.

[0034] Reference Figure 3 In one embodiment, the thickness of the central region 11 and the edge region 13 are constant along the length of the aluminum-plastic film, and at least one surface of the transition region 12 is a slope or curved surface; both sides of the edge region 13 are flat, or at least one surface of the edge region 13 is a slope or curved surface. In this embodiment, the thickness of the central region 11 and the edge region 13 is constant, there are no sharp points, and there is no puncture to the first anti-corrosion layer 21 and the second anti-corrosion layer 31 on their outer sides. The central region 11 and the edge region 13 are transitioned through the sloped transition region 12, resulting in a relatively simple and stable structure that is easy to process.

[0035] In other embodiments, the transition region 12 may be a curved surface.

[0036] In other embodiments, the edge region 13 may be a slope or a curved surface.

[0037] Reference Figure 4 In other embodiments, the thickness of the central region 11 is constant, and the thickness of the edge region 13 gradually decreases in the direction away from the transition region 12.

[0038] In other embodiments, the thickness of the aluminum foil substrate layer 1 gradually decreases from the center to the outer edge.

[0039] Reference Figure 1 and Figure 2In one embodiment, the aluminum foil substrate layer 1 has a first surface and a second surface opposite each other along its thickness direction; along the thickness direction of the aluminum-plastic film, the first surface protrudes toward the first anti-corrosion layer 21; the vertex of the first surface is located at the midline of the first surface; the side surface of the first composite layer 2 facing the first surface is adapted to the shape of the first surface. Along the thickness direction of the aluminum-plastic film, the second surface protrudes toward the second anti-corrosion layer 31; the vertex of the second surface is located at the midline of the second surface; the side surface of the second anti-corrosion layer 31 facing the second surface is adapted to the shape of the second surface.

[0040] Regardless of the shape of the first and second surfaces of the aluminum foil substrate layer 1, the surface of the first anti-corrosion layer 21 corresponding to the first surface is adapted to the shape of the first surface, enabling a stable bond between the first surface and the first anti-corrosion layer 21. Similarly, the second surface also achieves a stable bond with the second anti-corrosion layer 31 in this manner.

[0041] Reference Figure 1 and Figure 2 In one embodiment, both the first surface and the second surface are curved surfaces, and along the length of the aluminum-plastic film, the first surface and the second surface approach each other from the center away from the center of the aluminum-plastic film.

[0042] In one embodiment, both the first and second surfaces are curved surfaces, and along the length of the aluminum-plastic film, the first and second surfaces are close to each other away from the center of the aluminum-plastic film. In this embodiment, the aluminum foil substrate layer 1 can be thinned in a curved manner from the middle, thereby forming a weak area after the aluminum-plastic film is made into the battery casing 4.

[0043] Reference Figure 5 and Figure 7 In one embodiment, the present invention also provides a housing 4, which is formed by folding the aforementioned aluminum-plastic film along a preset axis. The aluminum-plastic film is punched with pits on both sides along the preset axis to form the first receiving groove 41. The two first receiving grooves 41 are interconnected after the aluminum-plastic film is folded to form a closed first inner cavity, which is used to accommodate the battery cell. The side of the first composite layer 2 that is away from the aluminum foil substrate layer 1 is located on the side of the aluminum-plastic film closer to the battery cell. The aluminum-plastic film at the location corresponding to the central region 11 at least partially forms the bottom of the battery casing 4; the aluminum-plastic film at the location corresponding to the edge region 13 at least partially forms the top seal of the battery casing 4.

[0044] In this embodiment, before the aluminum-plastic film is folded in half, first receiving grooves 41 are formed by punching indentations on both sides of the aluminum-plastic film along a preset axis. After the aluminum-plastic film is folded in half, the two first receiving grooves 41 are aligned and connected, forming a first inner cavity for accommodating the battery cell. Generally, the preset axis is located in the middle of the length direction of the aluminum-plastic film, and the first receiving groove 41 is a square groove with four corners at the bottom. The closer the first receiving groove 41 is to the preset axis, the thicker the aluminum foil substrate layer 1 is, that is, the thicker the wall of the receiving groove is. The thicker the wall at the bottom corner of the casing, the better it is to prevent corner cracking. The thickness at the two corners of the first receiving groove 41 away from the preset axis is thinner, and these two corners are also weak areas that can be used for pressure relief. Therefore, it can be seen that the battery casing 4 in this embodiment not only forms a weak area at the top of the casing 4, but also forms a weak area in the first receiving groove 41. The weak areas mentioned above can all be used for pressure relief.

[0045] Reference Figure 6 In one embodiment, the present invention also provides a housing 4, which is formed by folding the aforementioned aluminum-plastic film along a preset axis. The aluminum-plastic film is punched with a hole on one side along the preset axis to form the first receiving groove 41. The first receiving groove 41 forms a closed second inner cavity after the aluminum-plastic film is folded, and the second inner cavity is used to accommodate the battery cell. The side of the first composite layer 2 that is away from the aluminum foil substrate layer 1 is located on the side of the aluminum-plastic film closer to the battery cell. The aluminum-plastic film at the location corresponding to the central region 11 at least partially forms the bottom of the battery casing 4; the aluminum-plastic film at the location corresponding to the edge region 13 at least partially forms the top seal of the battery casing 4.

[0046] In this embodiment, before folding, the aluminum-plastic film has a first receiving groove 41 formed by punching a hole on one side of the preset axis, while the other side is a flat aluminum-plastic film. After folding, the aluminum-plastic film on one side covers the first receiving groove 41 to form a closed second inner cavity, which is used to accommodate the battery cell.

[0047] Reference Figure 5 and Figure 7 The aluminum-plastic film corresponds to the part of the central area 11, forming the bottom of the battery housing 4, or forming the bottom of the battery housing 4 and the transition part between the bottom of the housing 4 and the side of the housing 4.

[0048] The aluminum-plastic film, corresponding to the edge region 13, forms the top seal of the battery casing 4, or a portion of the top seal and top edge of the battery casing 4, thereby reinforcing easily damaged parts of the casing and preventing corner cracks at the bottom corners of the casing. Whether the edge region 13 of the aluminum-plastic film forms the top seal, the top seal, or a portion of the top edge of the battery casing 4, it facilitates gas passage through the central region 11 when the battery is in an abnormal state.

[0049] In one embodiment, the present invention also provides a battery, including the aforementioned casing 4.

[0050] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. An aluminum-plastic film, characterized in that, It includes a first composite layer (2), an aluminum foil substrate layer (1), and a second composite layer (3); Along the length of the aluminum-plastic film, the aluminum foil substrate layer (1) is divided into a central area (11), a transition area (12), and an edge area (13) from its middle part to its single edge; the thickness of the central area (11) is greater than the thickness of the edge area (13); the thickness of the transition area (12) decreases from the central area (11) to the edge area (13); The first composite layer (2) and the second composite layer (3) respectively cover the opposite sides of the aluminum foil substrate layer (1); The side of the first composite layer (2) away from the aluminum foil substrate layer (1) is set as a plane, and the side of the second composite layer (3) away from the aluminum foil substrate layer (1) is set as a plane; The portion of the aluminum-plastic film corresponding to the central region (11) is at least partially used to form the bottom of the battery casing (4); the portion of the aluminum-plastic film corresponding to the edge region (13) is at least partially used to form the top seal of the battery casing (4).

2. The aluminum-plastic film according to claim 1, characterized in that, Along the length of the aluminum-plastic film, one side of the aluminum foil substrate layer (1) gradually approaches the other side of the aluminum foil substrate layer (1) from the middle outwards, or... Along the length of the aluminum-plastic film, the two sides of the aluminum foil substrate layer (1) gradually move towards the other side of the aluminum foil substrate layer (1) from the middle to the outer edge.

3. The aluminum-plastic film according to claim 1, characterized in that, The first composite layer (2) includes a first anti-corrosion layer (21), and the second composite layer (3) includes a second anti-corrosion layer (31); The first anti-corrosion layer (21) and the second anti-corrosion layer (31) respectively cover the opposite sides of the aluminum foil substrate layer (1); the side of the first anti-corrosion layer (21) away from the aluminum foil is set as a plane, and the side of the second anti-corrosion layer (31) away from the aluminum foil substrate layer (1) is set as a plane.

4. The aluminum-plastic film according to claim 3, characterized in that, The first composite layer (2) further includes a first adhesive layer (22) and a sealing layer (23) sequentially disposed on the first anti-corrosion layer (21), and the second composite layer (3) further includes a second adhesive layer (32) and a substrate layer (33) sequentially disposed on the second anti-corrosion layer (31); The sealing layer (23) is used to form the inner side of the battery casing (4); Along the length of the aluminum-plastic film, the sum of the thicknesses of the first adhesive layer (22) and the sealing layer (23) is constant; Along the length of the aluminum-plastic film, the sum of the thicknesses of the second adhesive layer (32) and the substrate layer (33) is constant.

5. The aluminum-plastic film according to claim 1, characterized in that, The first composite layer (2) includes a first anti-corrosion layer (21), a first adhesive layer (22) and a sealing layer (23) arranged in sequence, and the second composite layer (3) includes a second anti-corrosion layer (31), a second adhesive layer (32) and a substrate layer (33) arranged in sequence; The first anti-corrosion layer (21) and the second anti-corrosion layer (31) respectively cover the opposite sides of the aluminum foil substrate layer (1); Along the length of the aluminum-plastic film: the thickness of the first anti-corrosion layer (21) is constant, and the thickness of the second anti-corrosion layer (31) is constant; the side of the first adhesive layer (22) away from the first anti-corrosion layer (21) is planar, and the side of the second adhesive layer (32) away from the second anti-corrosion layer (31) is planar; along the length of the aluminum-plastic film: the thickness of the sealing layer (23) is constant, and the thickness of the substrate layer (33) is constant; or, Along the length of the aluminum-plastic film: the thickness of the first anti-corrosion layer (21) is constant, the thickness of the second anti-corrosion layer (31) is constant, the thickness of the first adhesive layer (22) is constant, and the thickness of the second adhesive layer (32) is constant; the side of the sealing layer (23) away from the first adhesive layer (22) is set as a plane, and the side of the substrate layer (33) away from the second adhesive layer (32) is set as a plane.

6. The aluminum-plastic film according to claim 1, characterized in that, Along the length of the aluminum-plastic film, the thickness of the aluminum foil substrate layer (1) gradually decreases from the center to the outer edge; or, The thickness of the central region (11) is constant, and the thickness of the edge region (13) is constant; or, The thickness of the central region (11) is constant, and the thickness of the edge region (13) gradually decreases in the direction away from the transition region (12).

7. The aluminum-plastic film according to claim 6, characterized in that, At least one surface of the transition region (12) is an inclined surface or a curved surface; The two sides of the edge region (13) are planes, or at least one side of the edge region (13) is an inclined plane or a curved surface.

8. The aluminum-plastic film according to claim 3, characterized in that, The aluminum foil substrate layer (1) has a first surface and a second surface opposite to each other along its thickness direction; Along the thickness direction of the aluminum-plastic film, the first surface protrudes toward the first anti-corrosion layer (21); the vertex of the first surface is located at the center line of the first surface; The side surface of the first composite layer (2) facing the first surface is adapted to the shape of the first surface; Along the thickness direction of the aluminum-plastic film, the second surface protrudes toward the second anti-corrosion layer (31); the vertex of the second surface is located at the center line of the second surface; The side surface of the second anti-corrosion layer (31) facing the second surface is adapted to the shape of the second surface.

9. The aluminum-plastic film according to claim 8, characterized in that, Both the first surface and the second surface are curved surfaces. Along the length of the aluminum-plastic film, the first surface and the second surface are close to each other away from the center of the aluminum-plastic film.

10. A battery casing (4), characterized in that, The aluminum-plastic film according to any one of claims 1-9 is folded along a preset axis, and the aluminum-plastic film is punched along at least one side of the preset axis to form a first receiving groove (41), the first receiving groove (41) is used to receive the battery cell; The side of the first composite layer (2) facing away from the aluminum foil substrate layer (1) is located on the side of the aluminum-plastic film closer to the battery cell; The aluminum-plastic film at the part corresponding to the central area (11) at least partially forms the bottom of the battery casing (4); the aluminum-plastic film at the part corresponding to the edge area (13) at least partially forms the top seal of the battery casing (4).

11. The battery casing (4) according to claim 10, characterized in that, The aluminum-plastic film corresponds to the part of the central area (11) to form the bottom of the battery housing (4), or to form the bottom of the battery housing (4) and the transition part between the bottom of the housing (4) and the side of the housing (4); The aluminum-plastic film, corresponding to the edge area (13), forms the top seal of the battery housing (4), or forms the top seal and part of the top edge of the battery housing (4).

12. A battery, characterized in that, Includes the housing (4) as described in any one of claims 10 or 11.

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