A black light-shielding aluminum-plastic composite packaging film for lithium-ion batteries

Abstract

The invention relates to a black light-shielding type aluminum-plastic composite packaging film for lithium-ion batteries. The aluminum-plastic film comprises a copolypropylene layer CPP, an adhesive layer, an aluminum foil layer AL, an adhesive layer, a polyethylene terephthalate black PET layer, an adhesive layer, and a nylon layer PA, which are sequentially the copolypropylene layer CPP, the adhesive layer, the aluminum foil layer AL, the adhesive layer, the polyethylene terephthalate black PET layer, the adhesive layer, and the nylon layer PA from the inside to the outside. In the invention, the black PET layer is used for composite, and compared with the traditional aluminum-plastic film, the aluminum-plastic film has better light-shielding performance, heat dissipation performance, insulation performance and chemical stability, and prolongs the service life of the aluminum-plastic film.

Description

Technical Field

[0001] The invention relates to the field of battery packaging materials, in particular to a black light-shielding lithium-ion battery composite packaging aluminum-plastic film. Background Art

[0002] In recent years, with the increase in lithium battery technology and production, the demand for lithium battery packaging materials has also increased. Lithium battery packaging materials have begun to use aluminum-plastic film to replace traditional steel shells. Aluminum-plastic film packaging materials have become the mainstream of lithium battery packaging material application development in the future.

[0003] Traditional aluminum-plastic film is basically composed of an outer protective layer, an intermediate aluminum foil barrier layer and an inner heat-sealing layer. The layers are bonded with adhesives. The outer protective layer is generally made of nylon. Polyethylene terephthalate (PET) is also selected for reinforced composite to improve the barrier and friction resistance of the composite material. However, during the use of batteries, the light-shielding and heat-dissipating properties of traditional composite films are not very good, which will lead to premature aging of the material and possible degradation of the adhesive curing molecules during long-term use of aluminum-plastic film, which needs further improvement. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a black light-shielding lithium-ion battery composite packaging aluminum-plastic film, which should have excellent light-shielding performance, heat dissipation performance, barrier performance and chemical stability performance.

[0005] To solve the above technical problems, the technical solution of the present invention is: a black light-shielding lithium-ion battery composite packaging aluminum-plastic film, which comprises, from inside to outside: a copolymer polypropylene layer CPP, a first adhesive layer, an aluminum foil layer AL, a second adhesive layer, a polyethylene terephthalate black PET layer, a third adhesive layer, and a nylon layer PA.

[0006] Preferably, the surface of the aluminum foil layer AL is passivated by chromization, and the thickness of the aluminum foil layer AL is 20-60 μm.

[0007] Preferably, the copolypropylene layer CPP has a thickness of 10-80 μm, and the composite surface is subjected to corona treatment before composite.

[0008] Preferably, the black polyethylene terephthalate PET layer has a thickness of 10-50 μm, and the black polyethylene terephthalate PET layer is subjected to corona treatment on both sides before lamination. Preferably, the black polyethylene terephthalate PET layer material is prepared by melt blending, extrusion and film blowing of PET and carbon black.

[0009] Preferably, the thickness of the nylon layer PA is 10-50 μm, and the surface of the nylon layer PA in contact with the black polyethylene terephthalate PET layer is subjected to corona treatment.

[0010] After adopting the above technical solution, the beneficial effects of the present invention are:

[0011] First, the use of black PET in the aluminum-plastic film can improve the light-shielding and heat-dissipating properties of the aluminum-plastic film, reduce the light absorption intensity of the inner layer material and the cured molecules of the adhesive layer, and improve the anti-aging properties of the material and the cured molecules; secondly, the protective layer of the aluminum-plastic film uses black PET and nylon for double-layer protection, which can more effectively block water vapor and improve the chemical stability of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of a black light-shielding lithium-ion battery composite packaging aluminum-plastic film of the present invention.

[0013] 1. Copolypropylene layer CPP, 2. First adhesive layer, 3. Aluminum foil layer AL, 4. Second adhesive layer, 5. Polyethylene terephthalate black PET layer, 6. Third adhesive layer, 7. Nylon layer PA. DETAILED DESCRIPTION

[0014] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0015] like Figure 1 As shown, the present invention provides a black light-shielding lithium-ion battery composite packaging aluminum-plastic film, comprising a copolymerized polypropylene layer CPP (1), a first adhesive layer (2), an aluminum foil layer AL (3), a second adhesive layer (4), a polyethylene terephthalate black PET layer (5), a third adhesive layer (6), and a nylon layer PA (7).

[0016] The barrier layer is an aluminum foil layer, and the surface of the aluminum foil layer AL is passivated by chromization. The chromization can improve the adhesion between the aluminum foil layer AL and other resins. The thickness of the aluminum foil layer AL is 20-60 μm. In this embodiment, the thickness of the aluminum foil layer AL is 30 μm-40 μm. The thickness of the aluminum foil layer AL is 30 μm-40 μm, which can ensure complete water vapor barrier and effectively reduce the manufacturing cost of the aluminum-plastic film.

[0017] The heat sealing layer is a copolymerized polypropylene layer, the copolymerized polypropylene layer CPP thickness is 10-80 μm, preferably 15-55 μm in this embodiment, and is subjected to corona treatment on the composite surface with the aluminum foil.

[0018] The black polyethylene terephthalate PET layer has a thickness of 10-50 μm, preferably 20-30 μm in this embodiment, and is subjected to double-sided corona treatment.

[0019] The thickness of the nylon layer PA is 10-50 μm. In this embodiment, the thickness of the nylon layer is preferably 15-35 μm, and the composite surface with the black PET is subjected to corona treatment.

[0020] The manufacturing process steps of the aluminum-plastic film are as follows:

[0021] 1. Plasma corona treatment is performed on the CPP composite surface of the copolypropylene layer, the PA composite surface of the nylon layer, and the black PET double surfaces of polyethylene terephthalate;

[0022] 2. Roller-coat the aluminum foil layer AL with adhesive on both sides, and compound the aluminum foil layer AL with co-polypropylene layer CPP and polyethylene terephthalate black PET on both sides of the aluminum foil layer AL, and dry;

[0023] 3. Roll-coat the adhesive on the PET surface of the copolypropylene layer CPP / aluminum foil layer AL / polyethylene terephthalate black PET, and compound it with the nylon layer PA, and dry it.

[0024] The product of the present invention has achieved the following indicators after measurement:

[0025] 1. Peel strength test: Immerse in electrolyte at 85°C for 7 days, the interlayer peel strength of AL / CPP, AL / black PET / PA is greater than or equal to 8N / 15mm;

[0026] 2. Anti-penetration test: Soaked in 60℃ water for 14 days, no delamination, weight change is less than 0.05g.

[0027] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A black light-shielding lithium-ion battery composite packaging aluminum-plastic film, characterized in that: The aluminum-plastic film comprises a copolypropylene layer CPP, a first adhesive layer, an aluminum foil layer AL, a second adhesive layer, a polyethylene terephthalate black PET layer, a third adhesive layer, and a nylon layer PA, which are, from inside to outside, the following: copolypropylene layer CPP (1), the first adhesive layer (2), the aluminum foil layer AL (3), the second adhesive layer (4), the polyethylene terephthalate black PET layer (5), the third adhesive layer (6), and the nylon layer PA (7); The copolypropylene layer CPP has a thickness of 10-80 μm, and the composite surface is subjected to corona treatment before composite; The surface of the aluminum foil layer AL is passivated by chromization, and the thickness of the aluminum foil layer AL is 20-60 μm; The black polyethylene terephthalate PET layer has a thickness of 10-50 μm, and the black polyethylene terephthalate PET layer is subjected to corona treatment on both sides before compounding; the black polyethylene terephthalate PET layer material is prepared by melt blending, extruding, and blowing film of PET and carbon black.

2. The black light-shielding lithium-ion battery composite packaging aluminum-plastic film according to claim 1, characterized in that: The thickness of the nylon layer PA is 10-50 μm, and the surface of the nylon layer PA in contact with the polyethylene terephthalate black PET layer is subjected to corona treatment.

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