Composite aluminum plastic film, packaging structure and battery

Abstract

The utility model provides a composite aluminum plastic film, a packaging structure and a battery. The composite aluminum plastic film comprises a polytetrafluoroethylene outer layer, a secondary outer layer, an aluminum foil middle layer, a secondary inner layer and a nylon inner layer which are sequentially stacked and connected with one another, wherein the secondary outer layer comprises kaolin and at least one of polyethylene glycol terephthalate, polyvinylidene fluoride and nylon; the secondary inner layer comprises kaolin and at least one of polyethylene glycol terephthalate, polyvinylidene fluoride and nylon. The composite aluminum plastic film provided by the utility model has excellent puncture resistance, high temperature resistance, oil bubble resistance, bending resistance and gas barrier property.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of battery packaging, specifically relates to a composite aluminum plastic film, packaging structure, battery. BACKGROUND

[0002] The aluminum plastic film commonly used in the market at present usually adopts a hot-press sealing process and is composed of an outer base resin layer, an intermediate aluminum foil layer and a hot-melt resin layer, and is compounded by using an adhesive or a thermoplastic resin flow casting method. The aluminum plastic film is mainly applied to the field of soft-pack batteries due to its good electrolyte corrosion resistance, moisture insulation performance and processing performance.

[0003] However, the puncture resistance of the aluminum plastic film is relatively low, the bending resistance is poor and the temperature durability is limited, which restricts its application in a wider field.

[0004] Therefore, developing a composite film with puncture resistance, high-temperature resistance, oil bubble resistance, bending resistance and gas barrier property can help to apply it to more scenarios. UTILITY MODEL CONTENTS

[0005] The utility model provides a kind of composite aluminum plastic film, packaging structure, battery, to solve the problem that the puncture resistance, high-temperature resistance, oil bubble resistance, bending resistance of aluminum plastic film in prior art still be poor with many properties such as gas barrier property.

[0006] The utility model provides a kind of composite aluminum plastic film in one aspect, including sequentially laminated and mutually connected polytetrafluoroethylene outer layer, secondary outer layer, aluminum foil intermediate layer, secondary inner layer and nylon inner layer;

[0007] Wherein, the secondary outer layer includes at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin;

[0008] The secondary inner layer includes at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin.

[0009] The composite aluminum plastic film described above, at least one between the polytetrafluoroethylene outer layer and the secondary outer layer, between the secondary outer layer and the aluminum foil intermediate layer, between the aluminum foil intermediate layer and the secondary inner layer, between the secondary inner layer and the nylon inner layer is connected by bonding layer.

[0010] The composite aluminum plastic film described above, the thickness of the polytetrafluoroethylene outer layer is 50-100 μm;And / or,

[0011] The thickness of the secondary outer layer is 15-35 μm;And / or,

[0012] The thickness of the aluminum foil intermediate layer is 15-55 μm;And / or,

[0013] the thickness of the secondary inner layer is 15-35 μm; and / or,

[0014] the thickness of the nylon inner layer is 50-100 μm; and / or,

[0015] the thickness of the adhesive layer is 3-6 μm.

[0016] The composite aluminum-plastic film as described above, wherein the mass percentage of the kaolin in the secondary outer layer is 1-10%; and / or,

[0017] the mass percentage of the kaolin in the secondary inner layer is 1-10%.

[0018] the mass percentage of the kaolin in the secondary inner layer is 1-10%.

[0019] The composite aluminum-plastic film as described above, wherein the polytetrafluoroethylene outer layer is a uniaxially stretched polytetrafluoroethylene film; and / or,

[0020] the nylon inner layer is a uniaxially stretched nylon film.

[0021] The composite aluminum-plastic film as described above, wherein the melting point of the polytetrafluoroethylene outer layer is 320-330℃; and / or,

[0022] the melting point of the secondary outer layer is 260-270℃; and / or,

[0023] the melting point of the aluminum foil intermediate layer is 600-660℃; and / or,

[0024] the melting point of the secondary inner layer is 230-240℃; and / or,

[0025] the melting point of the nylon inner layer is 190-200℃; and / or,

[0026] the melting point of the adhesive layer is 210-230℃.

[0027] The composite aluminum-plastic film as described above, wherein at least one of the nylon in the secondary inner layer, the nylon in the secondary outer layer, and the nylon in the nylon inner layer is selected from at least one of nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, and nylon 612.

[0028] The composite aluminum-plastic film as described above, wherein the adhesive layer comprises a bi-component polyurethane.

[0029] The utility model discloses still one aspect provides a kind of packaging structure, including the composite aluminum-plastic film as described above.

[0030] The packaging structure adopts electromagnetic induction treatment for packaging.

[0031] The utility model discloses still one aspect provides a battery, including electric core and as above-mentioned packaging structure, the electric core is encapsulated in the packaging structure.

[0032] Through setting the secondary outer layer of at least one of kaolin blended polyethylene terephthalate, polyvinylidene fluoride and nylon in the polytetrafluoroethylene outer layer and aluminum foil intermediate layer, and the secondary inner layer of at least one of kaolin blended polyethylene terephthalate, polyvinylidene fluoride and nylon in the aluminum foil intermediate layer and nylon outer layer, through the synergistic collocation of each layer, the chemical stability, high and low temperature resistance of the composite aluminum plastic film can be improved, the composite aluminum plastic film can resist corrosion of various chemical reagents, oil and the like and ensure its use stability in high and low temperature environment, and the bending resistance, puncture resistance and barrier property of the composite aluminum plastic film can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 For the composite aluminum plastic film in the embodiment of the utility model.

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] A: polytetrafluoroethylene outer layer;

[0036] B: secondary outer layer;

[0037] C: aluminum foil intermediate layer;

[0038] D: secondary inner layer;

[0039] E: nylon inner layer;

[0040] F: adhesive layer. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme in the embodiment of the utility model will be described clearly and completely below in conjunction with the embodiment of the utility model, obviously, the described embodiment is a part of the embodiment of the utility model, rather than all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0042] On the one hand, as Figure 1 The utility model provides a composite aluminum plastic film, including polytetrafluoroethylene outer layer A, secondary outer layer B, aluminum foil intermediate layer C, secondary inner layer D and nylon inner layer E that are sequentially laminated and are connected each other;

[0043] The secondary outer layer B comprises at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin.

[0044] The secondary inner layer D comprises at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin.

[0045] The arrangement order of each layer is defined by the sequential stacking and mutual connection, which can be direct connection or indirect connection. Specifically, the surface of the polytetrafluoroethylene outer layer A is connected with the secondary outer layer B, the surface of the secondary outer layer B away from the polytetrafluoroethylene outer layer A is connected with the aluminum foil intermediate layer C, the surface of the aluminum foil intermediate layer C away from the secondary outer layer B is connected with the secondary inner layer D, and the surface of the secondary inner layer D away from the aluminum foil intermediate layer C is connected with the nylon inner layer E.

[0046] The secondary outer layer comprises at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin, and the secondary inner layer comprises at least one of polyethylene terephthalate, polyvinylidene fluoride, nylon and kaolin, which can improve the overall bending resistance and puncture resistance of the film material, and improve the barrier property of the film material. By arranging the secondary outer layer between the polytetrafluoroethylene outer layer and the aluminum foil intermediate layer, and arranging the secondary inner layer between the aluminum foil intermediate layer and the nylon outer layer, the chemical stability and high and low temperature resistance of the composite aluminum plastic film can be improved through the synergistic matching of each layer, so that the composite aluminum plastic film can resist corrosion of various chemical reagents, oil and the like and ensure its use stability in high and low temperature environments, and the bending resistance, puncture resistance and barrier property of the composite aluminum plastic film can be improved.

[0047] Further, at least one of the connection between the polytetrafluoroethylene outer layer A and the secondary outer layer B, the connection between the secondary outer layer B and the aluminum foil intermediate layer C, the connection between the aluminum foil intermediate layer C and the secondary inner layer D, and the connection between the secondary inner layer D and the nylon inner layer E is connected through the adhesive layer F.

[0048] It can be understood that at least one of the connection between the polytetrafluoroethylene outer layer A and the secondary outer layer B, the connection between the secondary outer layer B and the aluminum foil intermediate layer C, the connection between the aluminum foil intermediate layer C and the secondary inner layer D, and the connection between the secondary inner layer D and the nylon inner layer E is connected through the adhesive layer F, which comprises an adhesive, and can further improve the puncture resistance, high temperature resistance, oil bubble resistance, bending resistance, gas barrier property and the like of the composite aluminum plastic film.

[0049] In a specific embodiment, the thickness of the polytetrafluoroethylene outer layer A is 50-100 μm; the thickness of the secondary outer layer B is 15-35 μm; the thickness of the aluminum foil intermediate layer C is 15-55 μm; the thickness of the secondary inner layer D is 15-35 μm; the thickness of the nylon inner layer E is 50-100 μm; and the thickness of the adhesive layer F is 3-6 μm.

[0050] By further limiting the thickness of each layer, the synergistic effect between each layer can be further enhanced, the chemical stability, high and low temperature resistance of the composite aluminum plastic film can be further improved, the corrosion resistance, bending resistance and puncture resistance can be further improved, and the barrier property of the composite aluminum plastic film can be improved.

[0051] In an embodiment, the secondary outer layer B is a kaolin-BOPET film, and the secondary inner layer D is a kaolin-BOPA film.

[0052] The kaolin-BOPET film refers to a kaolin and BOPET (biaxially oriented polyethylene terephthalate) blended film, and the kaolin-BOPA film refers to a kaolin and BOPA (biaxially oriented nylon) blended film. By arranging the kaolin-BOPET film between the polytetrafluoroethylene outer layer A and the aluminum foil intermediate layer C, and arranging the kaolin-BOPA film between the aluminum foil intermediate layer C and the nylon outer layer, the synergistic effect between each layer can be further enhanced, the chemical stability, high and low temperature resistance of the composite aluminum plastic film can be further improved, the corrosion resistance, bending resistance and puncture resistance can be further improved, and the barrier property of the composite aluminum plastic film can be improved.

[0053] Optionally, the mass percentage content of the kaolin in the secondary outer layer B is 1-10%, and the mass percentage content of the kaolin in the secondary inner layer D is 1-10%.

[0054] Further limiting the content of the kaolin in the secondary outer layer B or the secondary inner layer D can further improve the comprehensive performance of the kaolin-BOPET film or the kaolin-BOPA film, further improve the bending resistance and puncture resistance of the composite aluminum plastic film, and further improve the barrier property of the composite aluminum plastic film.

[0055] In an embodiment, the polytetrafluoroethylene outer layer A is a uniaxially stretched polytetrafluoroethylene film.

[0056] In another embodiment, the nylon inner layer E is a uniaxially stretched nylon film.

[0057] The inventors have found that when the polytetrafluoroethylene outer layer A is a uniaxially stretched polytetrafluoroethylene film and the nylon inner layer E is a uniaxially stretched nylon film, the chemical stability, high and low temperature resistance of the composite aluminum plastic film can be further improved, the corrosion resistance, bending resistance and puncture resistance can be further improved, and the barrier property of the composite aluminum plastic film can be improved.

[0058] Further, the melting point of the polytetrafluoroethylene outer layer A is 320-330°C, the melting point of the secondary outer layer B is 260-270°C, the melting point of the aluminum foil intermediate layer C is 600-660°C, the melting point of the secondary inner layer D is 230-240°C, the melting point of the nylon inner layer E is 190-200°C, and the melting point of the bonding layer F is 210-230°C.

[0059] When the melting point of each layer of the composite aluminum-plastic film is within the above-mentioned limited range, the mechanical properties and durability of the composite aluminum-plastic film can be further improved, the integrity of the structure of each layer is maintained, the synergistic effect of each layer is further improved, and the subsequent processing is facilitated.

[0060] Specifically, at least one of the nylon in the secondary inner layer D, the nylon in the secondary outer layer B, and the nylon in the nylon inner layer E is selected from at least one of nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, and nylon 612.

[0061] When at least one of the nylon in the secondary inner layer D, the nylon in the secondary outer layer B, and the nylon in the nylon inner layer E is selected from the above-mentioned limited nylon types, the chemical stability, high and low temperature resistance, corrosion resistance, bending resistance, and puncture resistance of the composite aluminum-plastic film can be further improved, and the barrier properties of the composite aluminum-plastic film are also improved.

[0062] The utility model discloses not limit the specific material of bonding layer F, and the bonding layer F that can play the connecting effect of each layer is all available, and the bonding layer F includes two-component polyurethane optionally.

[0063] It can be understood that each layer of the composite aluminum-plastic film is connected through the bonding layer F, and when the bonding layer F adopts two-component polyurethane, the chemical stability, high and low temperature resistance, corrosion resistance, bending resistance, and puncture resistance of the composite aluminum-plastic film can be further improved, and the barrier properties and peel strength of the composite aluminum-plastic film are also improved.

[0064] The bonding layer F can also include at least one of phenolic resin, epoxy resin, bismaleimide resin, and modified materials thereof.

[0065] It can be understood that each layer of material arranged in layers can be subjected to curing treatment together to enhance the bonding strength and performance; the utility model discloses not limit the method of curing treatment, and the common method in the art can be selected for curing treatment, for example, first, keep in a curing room at 50 DEG C for 24h, and then keep in a curing room at 80 DEG C for 48h; finally, cool down to complete the curing treatment, wherein the humidity of the curing room is controlled to be below 40%.

[0066] In a specific embodiment, the surface of the polytetrafluoroethylene outer layer A connected with the secondary outer layer B also includes sodium-naphthalene solution for activation treatment to enhance the bonding property of the polytetrafluoroethylene outer layer A, specifically, a sodium-naphthalene solution with a concentration of 0.4-0.8 mol / L is uniformly coated on the surface of the film material, the coating thickness is controlled to be 100-200 μm, and the film material surface is washed clean with alcohol and pure water after treatment in a dark room at room temperature for 2-5 min.

[0067] Secondly, this utility model provides a packaging structure, including the composite aluminum-plastic film of the first aspect.

[0068] The packaging structure provided by this utility model includes a composite aluminum-plastic film in the first aspect, which has excellent puncture resistance, high temperature resistance, oil immersion resistance, bending resistance, and gas barrier properties. It can be applied to fields including but not limited to vacuum packaging, soft-pack batteries, gas storage bags, etc., and has a wider range of applications.

[0069] For example, the packaging structure can be a sealed bag.

[0070] Furthermore, the encapsulation structure employs electromagnetic induction processing for encapsulation.

[0071] Electromagnetic induction treatment refers to the process by which eddy currents in a magnetic conductor under an alternating magnetic field cause friction and collisions between atoms inside the material, generating heat, which is then sealed under external pressure. Encapsulation structures that are encapsulated through electromagnetic induction treatment have superior peel strength.

[0072] In one specific embodiment, the electromagnetic induction process may include: folding a composite aluminum-plastic film in half so that the inner nylon layers correspond to each other, and performing electromagnetic induction processing on the remaining edges other than the folded edge for encapsulation; the electromagnetic induction process may also include: aligning the inner nylon layers of two composite aluminum-plastic films, and performing electromagnetic induction processing on all edges for encapsulation.

[0073] Thirdly, this utility model provides a battery, including a battery cell and a packaging structure, wherein the battery cell is packaged within the packaging structure.

[0074] The battery provided by this utility model encapsulates the battery cell through an encapsulation structure, which enables the battery to have better chemical stability, high and low temperature resistance, excellent resistance to corrosion from various chemical reagents and oils, and ensures its stability in high and low temperature environments, as well as better mechanical properties.

[0075] The following is a detailed description of a composite aluminum-plastic film provided by this utility model through specific embodiments.

[0076] Example 1

[0077] like Figure 1 As shown, the composite aluminum-plastic film of this embodiment includes a polytetrafluoroethylene outer layer A, a second outer layer B, an aluminum foil intermediate layer C, a second inner layer D, and a nylon inner layer E stacked sequentially. The polytetrafluoroethylene outer layer A and the second outer layer B are connected by a two-component polyurethane adhesive layer F, the second outer layer B and the aluminum foil intermediate layer C are connected by a two-component polyurethane adhesive layer F, the aluminum foil intermediate layer C and the second inner layer D are connected by a two-component polyurethane adhesive layer F, and the second inner layer D and the nylon inner layer E are connected by a two-component polyurethane adhesive layer F.

[0078] wherein the outer layer of polytetrafluoroethylene has a thickness of 65 μm and a melting point of 330 °C;

[0079] the secondary outer layer is a kaolin-BOPET film having a kaolin content of 5.5 wt%, a thickness of 15 μm and a melting point of 270 °C;

[0080] the aluminium foil intermediate layer has a thickness of 15 μm and a melting point of 610 °C;

[0081] the secondary inner layer is a kaolin-BOPA film having a kaolin content of 5 wt%, a thickness of 15 μm and a melting point of 240 °C;

[0082] the uniaxially stretched nylon inner layer has a thickness of 65 μm and a melting point of 200 °C;

[0083] the adhesive layer has a thickness of 3 μm and a melting point of 230 °C.

[0084] Example 2

[0085] The composite aluminium-plastic film of this example differs from that of Example 1 in that the aluminium foil intermediate layer has a thickness of 30 μm.

[0086] Example 3

[0087] The composite aluminium-plastic film of this example differs from that of Example 1 in that the aluminium foil intermediate layer has a thickness of 40 μm.

[0088] Example 4

[0089] The composite aluminium-plastic film of this example differs from that of Example 1 in that the aluminium foil intermediate layer has a thickness of 55 μm.

[0090] Example 5

[0091] The composite aluminium-plastic film of this example differs from that of Example 1 in that the aluminium foil intermediate layer has a thickness of 30 μm; the secondary outer and inner layers have a thickness of 25 μm.

[0092] Example 6

[0093] The composite aluminium-plastic film of this example differs from that of Example 1 in that the aluminium foil intermediate layer has a thickness of 30 μm; the secondary outer and inner layers have a thickness of 35 μm.

[0094] Example 7

[0095] The composite aluminium-plastic film of this example differs from that of Example 1 in that the outer layer of polytetrafluoroethylene has a thickness of 50 μm; the aluminium foil intermediate layer has a thickness of 30 μm; the nylon inner layer has a thickness of 50 μm.

[0096] Example 8

[0097] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 65 μm.

[0098] Example 9

[0099] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 80 μm.

[0100] Example 10

[0101] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 50 μm.

[0102] Example 11

[0103] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 80 μm.

[0104] Example 12

[0105] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 80 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 50 μm.

[0106] Example 13

[0107] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 80 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 65 μm.

[0108] Example 14

[0109] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 80 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 80 μm.

[0110] Comparative Example 1

[0111] The composite aluminum-plastic film of this example differs from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the intermediate layer of aluminum foil is 30 μm; the second outer layer is a PET (polyethylene terephthalate) film, the second inner layer is a PA (nylon) film; and the thickness of the inner layer of nylon is 80 μm.

[0112] Comparative Example 2

[0113] The composite aluminum-plastic film of the present comparative example is different from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the middle layer of aluminum foil is 30 μm; and the thickness of the inner layer of nylon is 80 μm, without the outer secondary layer and the inner secondary layer.

[0114] Comparative Example 3

[0115] The composite aluminum-plastic film of the present comparative example is different from that of Example 1 in that the outer layer of polytetrafluoroethylene is replaced by a PA film with a thickness of 50 μm and a melting point of 230 ℃; the thickness of the middle layer of aluminum foil is 30 μm; there is no outer secondary layer and no inner secondary layer; and the thickness of the inner layer of nylon is 80 μm.

[0116] Comparative Example 4

[0117] The composite aluminum-plastic film of the present comparative example is different from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the middle layer of aluminum foil is 30 μm; and the inner layer of nylon is replaced by a PP (polypropylene) film with a thickness of 80 μm.

[0118] Comparative Example 5

[0119] The composite aluminum-plastic film of the present comparative example is different from that of Example 1 in that the thickness of the outer layer of polytetrafluoroethylene is 50 μm; the thickness of the middle layer of aluminum foil is 30 μm; and the inner layer of nylon is replaced by a PE (polyethylene) film with a thickness of 80 μm.

[0120] Test Example 1

[0121] The two-layer composite aluminum-plastic films in the above examples and comparative examples are sealed by using an electromagnetic induction sealing machine to obtain a packaging structure; wherein the inner layers of nylon of the two-layer composite aluminum-plastic films are connected.

[0122] The packaging structure is subjected to performance testing:

[0123] The puncture strength is tested according to GB / T 10004 2008;

[0124] The bending fatigue degree is tested according to GB / T 2679.5-1995;

[0125] The tensile strength is tested according to GB / T 1040.3—2006;

[0126] The peeling strength is tested according to GB / T 8808-1988;

[0127] The oxygen permeation rate is tested according to ASTM:F 1927;

[0128] The water vapor permeation rate is tested according to ASTM:F 1249;

[0129] The high-temperature resistance was tested by placing the packaging structure in 130℃ air and 130℃ shock-absorbing oil for 100 hours, and then checking the appearance, and testing the tensile strength and peel strength according to the above national standards.

[0130] The two-layer composite aluminum-plastic film in the above examples and comparative examples was sealed by a hot-press sealing machine to obtain a packaging structure, wherein the nylon inner layers of the two-layer composite aluminum-plastic film were connected. The peel strength of the packaging structure obtained by hot-press sealing was tested according to GB / T 8808-1988.

[0131] The test results are shown in Tables 1 and 2.

[0132] Table 1

[0133]

[0134]

[0135] According to Table 1, as the thickness of the aluminum foil in the composite aluminum-plastic film increases, the puncture strength gradually increases. Similarly, as the thickness of the outer layer and the inner layer increases, the puncture strength also increases, but the amplitude is not large. Compared with the control group without adding biaxially oriented film, the puncture strength of the experimental group with biaxially oriented film is obviously improved, but increasing the thickness of the biaxially oriented film does not have a greater improvement effect.

[0136] As the thickness of the aluminum foil in the composite aluminum-plastic film increases, the bending fatigue degree first increases and then decreases. Similarly, as the thickness of the outer layer and the inner layer increases, the bending fatigue degree first increases and then decreases. Overall, too high or too low film thickness is not conducive to bending. Compared with the control group without adding biaxially oriented film, the bending fatigue degree of the experimental group with biaxially oriented film is obviously improved, but increasing the thickness of the biaxially oriented film does not have a greater improvement effect.

[0137] As the thickness of the aluminum foil in the composite aluminum-plastic film increases, the tensile strength increases. Similarly, as the thickness of the outer layer and the inner layer increases, the tensile strength also increases. Compared with the control group without adding biaxially oriented film, the tensile strength of the experimental group with biaxially oriented film is slightly improved.

[0138] As the overall film thickness in the composite aluminum-plastic film increases, the peel strength first increases and then decreases, and too high overall film thickness is not conducive to sealing strength. For this kind of composite aluminum-plastic film special for electromagnetic induction sealing, the electromagnetic induction sealing strength is much greater than the hot-press sealing strength. Moreover, the peel strength of the composite aluminum-plastic film of the utility model after high-temperature (air and oil bubble) does not decrease much, and the high-temperature resistance is significantly improved compared with the polyethylene and polypropylene sealing layer composite aluminum-plastic film.

[0139] As the thickness of the aluminum foil in the composite aluminum-plastic film increases, the oxygen transmission rate decreases. Similarly, as the thickness of the outer layer and the inner layer increases, the oxygen transmission rate slightly decreases.

[0140] With the increase of the thickness of the aluminum foil in the composite aluminum plastic film, the water vapor permeability is reduced; similarly, with the increase of the thickness of the outer layer and the inner layer, the water vapor permeability is slightly reduced.

[0141] Table 2

[0142]

[0143] According to Table 2, the packaging structure sealed by electromagnetic induction provided by the utility model has little decrease in tensile strength and peel strength after high temperature (air and oil bubble), and compared with the aluminum plastic film of the polyethylene and polypropylene sealing layer, the high temperature resistance is significantly improved.

[0144] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A composite aluminum-plastic film, characterized in that, It includes a polytetrafluoroethylene outer layer, a second outer layer, an aluminum foil middle layer, a second inner layer, and a nylon inner layer that are stacked and interconnected in sequence; The outermost layer is a film made of any one of kaolin-blended polyethylene terephthalate, polyvinylidene fluoride, and nylon. The innermost layer is a film made of any one of kaolin-blended polyethylene terephthalate, polyvinylidene fluoride, or nylon.

2. The composite aluminum-plastic film according to claim 1, characterized in that, At least one of the following connections is made between the polytetrafluoroethylene outer layer and the sub-outer layer, between the sub-outer layer and the aluminum foil intermediate layer, between the aluminum foil intermediate layer and the sub-inner layer, and between the sub-inner layer and the nylon inner layer: an adhesive layer.

3. The composite aluminum-plastic film according to claim 2, characterized in that, The thickness of the polytetrafluoroethylene outer layer is 50–100 μm; and / or, The thickness of the subouter layer is 15–35 μm; and / or, The thickness of the aluminum foil interlayer is 15–55 μm; and / or, The thickness of the innermost layer is 15–35 μm; and / or, The thickness of the nylon inner layer is 50–100 μm; and / or, The thickness of the adhesive layer is 3~6μm.

4. The composite aluminum-plastic film according to claim 1, characterized in that, The outermost layer is a kaolin-BOPET membrane, and the innermost layer is a kaolin-BOPA membrane.

5. The composite aluminum-plastic film according to any one of claims 1-4, characterized in that, The outer layer of polytetrafluoroethylene is a uniaxially stretched polytetrafluoroethylene film; and / or... The inner nylon layer is a uniaxially stretched nylon film.

6. The composite aluminum-plastic film according to claim 2 or 3, characterized in that, The melting point of the polytetrafluoroethylene outer layer is 320–330°C; and / or, The melting point of the outermost layer is 260–270°C; and / or, The melting point of the aluminum foil interlayer is 600–660°C; and / or, The melting point of the innermost layer is 230–240°C; and / or, The melting point of the nylon inner layer is 190–200°C; and / or, The melting point of the adhesive layer is 210–230°C.

7. The composite aluminum-plastic film according to any one of claims 1-4, characterized in that, The nylon in the innermost layer, the nylon in the outermost layer, and the nylon in the innermost layer are selected from one of nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, and nylon 612.

8. The composite aluminum-plastic film according to claim 2 or 3, characterized in that, The adhesive layer comprises a two-component polyurethane.

9. A packaging structure, characterized in that, Includes the composite aluminum-plastic film as described in any one of claims 1-8.

10. The packaging structure according to claim 9, characterized in that, The encapsulation structure is encapsulated using electromagnetic induction processing.

11. A battery, characterized in that, It includes a battery cell and the packaging structure of claim 9 or 10, wherein the battery cell is packaged within the packaging structure.

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