Packaging film for packaging solid-state battery

Abstract

The utility model relates to the technical field of battery packaging, in particular to a packaging film for packaging a solid-state battery, which comprises an outer layer, a metal foil layer and an inner layer which are sequentially arranged from outside to inside, and the inner layer is a fluoroplastic layer. The utility model aims to overcome the defect that the inner-layer material of the conventional aluminum-plastic film structure is easy to age and lose efficacy in a long-term high-temperature environment, and provides the packaging film for packaging the solid-state battery, which can resist high temperature, meet the high working temperature requirement of the solid-state battery, prolong the service life of the battery and reduce the potential safety hazard in the use process.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery packaging technical field more specifically, relate to a kind of packaging film for solid-state battery packaging. BACKGROUND

[0002] At present, solid-state battery has higher energy density, excellent performance in harsh environment, high safety and other characteristics, so that the research and development of solid-state battery becomes a hot spot and mainstream direction of new energy industry. The problem of using which packaging method for solid-state battery also arises, and the previous battery packaging mostly uses metal or aluminum plastic film soft package and other materials. Metal packaging is safer than aluminum plastic film, but has low energy density. Aluminum plastic film is light in weight and has high energy density, but may have certain safety risks in extreme conditions. Traditional lithium-ion batteries use liquid electrolyte, and are limited by the boiling point of electrolyte solvent, so the normal operating temperature range is-20 DEG C~60 DEG C. Solid-state battery no longer uses electrolyte, so it can operate at high temperature. It is generally believed that the long-term operating temperature of solid-state battery is 80 DEG C~100 DEG C. In order to meet the high-temperature environment and high-energy density requirements of solid-state battery, high-temperature-resistant aluminum plastic film or steel plastic film needs to be used. The aluminum plastic film is generally composed of multiple layers, the inner layer is a polypropylene heat sealing layer, the middle layer is an aluminum foil layer, and the outer layer is a polyamide material layer or a polyamide and thermoplastic polyester composite. The materials are bonded together by adhesive. The heat sealing strength and mechanical strength of the inner layer polypropylene will continuously decrease after long-term operation at high temperature, which limits the application of aluminum plastic film as solid-state battery soft packaging. SUMMARY

[0003] The utility model aims at overcoming the poor continuous high-temperature resistance of existing aluminum plastic film soft package, and provides a packaging film for solid-state battery packaging, which can withstand high temperature, meet the high operating temperature requirements of solid-state battery, prolong the service life of the battery and reduce the safety hazards during use.

[0004] To solve the above technical problems, the utility model adopts the technical scheme of:

[0005] A packaging film for solid-state battery packaging is provided, which comprises an outer layer, a metal foil layer and an inner layer arranged from outside to inside. The inner layer is a fluoroplastic layer.

[0006] The outer layer material has high puncture strength and toughness, and can effectively protect the battery cell and other materials. The metal foil layer is located in the middle of the packaging film, has high ductility and stiffness, is beneficial to deep drawing forming and plays a supporting role. The fluoroplastic layer is the inner layer of the packaging film, has heat resistance, creep resistance, moisture resistance and gas resistance, etc. The fluoroplastic has very high heat resistance and maintains stable physical and chemical properties in a high temperature environment. The high temperature resistance range is usually between -80 DEG C and 200 DEG C, which is much higher than the long-term working temperature 80 DEG C~100 DEG C of the solid-state battery, and is the preferred solution for the inner layer material of the soft package film. The packaging film for packaging the solid-state battery has a multi-layer structure, and the packaging film has high temperature heat sealing property, high deep drawing depth, high temperature working durability and high pressure resistance.

[0007] Further, the material of the fluoroplastic layer is any one of polytrifluorochloroethylene, perfluoroethylene propylene copolymer, polyvinylidene chloride and polyvinyl fluoride. Preferably, the polytrifluorochloroethylene has a melting peak temperature of more than 220 DEG C.

[0008] Further, a slip agent layer is further included, and the slip agent layer is located on the outer surface of the outer layer. The addition of the slip agent layer can obtain a packaging film with low friction coefficient and improve the deep drawing depth of the packaging film.

[0009] Further, the material of the slip agent layer is any one of oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis-stearamide and ethylene bis-oleic acid amide. The concentration of the slip agent ranges from 0.05% to 0.5%.

[0010] Further, the outer layer is a polyamide material layer, and a first adhesive layer is arranged between the polyamide material layer and the metal foil layer. The polyamide material has excellent puncture strength, toughness and heat resistance, and can form protection for the battery cell and other materials as the outer layer of the packaging film. The polyamide material layer and the metal foil layer are bonded by the first adhesive layer.

[0011] Further, a second adhesive layer is arranged between the metal foil layer and the inner layer.

[0012] Further, the outer layer includes a thermoplastic polyester layer and a polyamide material layer arranged in sequence, and a third adhesive layer is arranged between the thermoplastic polyester layer and the polyamide material layer. The overall thickness of the outer layer is 15 microns to 40 microns, and the thickness of the single thermoplastic polyester layer can be 2 microns to 15 microns. The bonding surface needs to be subjected to corona treatment to achieve high bonding strength.

[0013] Further, the material of the polyamide material layer is any one of nylon 6 or nylon 66. The nylon has better heat resistance, high softening point, and can keep stable performance at high temperature. The nylon also has good electrical insulation performance, high volume resistivity, and high withstand voltage. Meanwhile, the nylon has good stability to various chemicals, and can resist the erosion of some solvents and chemicals.

[0014] Further, the material of the thermoplastic polyester layer is any one of polyethylene terephthalate or polybutylene terephthalate. The polyethylene terephthalate or polybutylene terephthalate layer has excellent physical and mechanical properties in a wide temperature range, and can be used at a long-term temperature of 120 DEG C. The thermoplastic polyester layer has excellent electrical insulation, and even at high temperature and high frequency, the electrical performance is still good. The thermoplastic polyester layer has good creep resistance, fatigue resistance, friction resistance, and dimensional stability.

[0015] Further, the metal foil layer is an aluminum foil layer or a steel foil layer, and the thickness is 30 μm to 150 μm. When the aluminum foil is used, the aluminum foil is preferably 8021 or 8079 series, and has high ductility and high mechanical properties.

[0016] Further, the thickness of the inner layer is 25 μm to 100 μm. The inner layer and the metal foil layer are bonded by the second adhesive.

[0017] Further, the first adhesive layer, the second adhesive layer, and the third adhesive layer are polyurethane series adhesives, and the thickness of the first adhesive layer, the second adhesive layer, and the third adhesive layer is 3 μm to 6 μm. The polyurethane adhesive is composed of a main agent and a curing agent. The main agent can be any one of polyester polyol and polyether polyol, and the curing agent is selected from aliphatic isocyanate or aromatic ring isocyanate.

[0018] Compared with the prior art, the packaging film has the advantages that:

[0019] The packaging film has a multi-layer structure, and includes a fluoroplastic inner layer, an aluminum foil layer or a steel foil layer, a polyamide material outer layer, or an outer layer composed of a polyamide material layer and a thermoplastic polyester layer. The inner and outer layers are bonded together by the adhesive and the aluminum foil layer or the steel foil layer to form a high-temperature-resistant packaging film. The packaging film has high punching depth, high-temperature working durability, and high pressure resistance. The fluoroplastic inner layer has the characteristics of heat resistance, solvent resistance, creep resistance, moisture resistance, and gas resistance, and can meet the high working temperature requirement of solid-state battery packaging, prolong the service life of the battery, and reduce the safety hazard in the use process. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a structural schematic view of the packaging film according to the present application;

[0021] Figure 2Structure diagram of the steel foil layer in the embodiment 1 of the utility model;

[0022] Figure 3 Structure diagram of the aluminum foil layer in the embodiment 2 of the utility model;

[0023] Figure 4 Structure diagram of the steel foil layer in the embodiment 2 of the utility model;

[0024] Figure 5 Structure diagram of the aluminum foil layer in the embodiment 3 of the utility model;

[0025] Figure 6 Structure diagram of the steel foil layer in the embodiment 3 of the utility model;

[0026] Figure 7 Structure diagram of the aluminum foil layer in the embodiment 4 of the utility model;

[0027] Figure 8 Structure diagram of the steel foil layer in the embodiment 4 of the utility model.

[0028] The illustration mark is explained as follows:

[0029] 1, polyamide material layer, 2, aluminum foil layer, 3, steel foil layer, 4, fluoroplastic layer, 5, first adhesive layer, 6, second adhesive layer, 7, thermoplastic polyester layer, 8, slip agent layer, 9, third adhesive layer. Specific implementation

[0030] The utility model will be further explained in connection with specific implementation. Among them, the drawing is only for example explanation, and the representation is only schematic diagram, and cannot be understood as the limitation of the patent; in order to better explain the embodiment of the utility model, some components of the drawing will be omitted, enlarged or reduced, and the size of actual product is not represented; for those skilled in the art, it is understandable that some well-known structures in the drawing and its description can be omitted.

[0031] The same or similar labels in the drawings of the embodiment of the utility model correspond to the same or similar components; in the description of the utility model, it is understood that if the orientation or position relationship indicated by the terms such as 'up', 'down', 'left', 'right' is based on the orientation or position relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicating or implying that the device or element must have a particular orientation, a particular orientation and operation, therefore the position relationship of the term in the drawing is only for example explanation, and cannot be understood as the limitation of the patent, for the ordinary skilled in the art, the specific meaning of the above terms can be understood according to the specific situation.

[0032] Embodiment 1

[0033] As Figure 1 and Figure 2 The utility model discloses a kind of packaging films for solid-state battery packaging, including outer layer, metal foil layer, inner layer 4 sequentially arranged from outside to inside, and inner layer 4 is fluoroplastic layer.

[0034] The outer layer material has high puncture strength and toughness, which can effectively protect the battery cell and other materials. The metal foil layer is located in the middle of the packaging film and has high ductility and stiffness, which is beneficial to deep drawing forming and plays a supporting role. The fluoroplastic layer is the inner layer of the packaging film and has heat resistance, creep resistance, moisture and gas resistance, etc. Fluoroplastics have very high heat resistance and maintain stable physical and chemical properties in high temperature environments. Its high temperature resistance range is usually between -80℃ and 200℃, which is much higher than the long-term working temperature of 80℃~100℃ of solid-state batteries, and is the preferred solution for the inner layer material of the soft package film. The packaging film for solid-state battery packaging has a multi-layer structure, and the packaging film has high temperature heat sealing property, high deep drawing depth, high temperature working durability and high pressure resistance.

[0035] As an embodiment of the utility model, the outer layer is a polyamide material layer, and a first adhesive layer is provided between the polyamide material layer and the metal foil layer. Polyamide material has excellent puncture strength, toughness and heat resistance, and can form protection for the battery cell and other materials as the outer layer of the packaging film. The polyamide material layer and the metal foil layer are bonded by the first adhesive layer. More preferably, the outer layer is a nylon layer.

[0036] As an embodiment of the utility model, the material of the fluoroplastic layer is any one of polytrifluorochloroethylene, perfluoroethylene propylene copolymer, polyvinylidene chloride, and polyvinyl fluoride. Polytrifluorochloroethylene is preferred, and the selected polytrifluorochloroethylene has a melting peak temperature above 220℃.

[0037] The outer layer material has high puncture strength and toughness, which can effectively protect the battery cell and other materials. The metal foil layer is located in the middle of the packaging film and has high ductility, which is beneficial to deep drawing forming and plays a supporting role. The fluoroplastic layer 4 is the inner layer of the packaging film and has heat resistance, creep resistance, moisture and gas resistance, etc. Fluoroplastics have very high heat resistance and maintain stable physical and chemical properties in high temperature environments. Its high temperature resistance range is usually between -80℃ and 200℃, which is much higher than the long-term working temperature of 80℃~100℃ of solid-state batteries, and is the preferred solution for the inner layer material of the soft package film. The packaging film for solid-state battery packaging has a multi-layer structure, and the packaging film has high temperature heat sealing property, high deep drawing depth, high temperature working durability and high pressure resistance.

[0038] As an embodiment of the utility model, the nylon layer and the metal foil layer are bonded by the first adhesive layer 5. The nylon layer and the metal foil layer of the packaging film are reliably connected by bonding.

[0039] As an embodiment of the utility model, the first adhesive layer 5 adopts polyurethane series adhesive, and the thickness of the first adhesive layer 5 is 3 μm~6 μm.

[0040] As an embodiment of the utility model, the metal foil layer and the inner layer 4 are bonded by the second adhesive layer 6.

[0041] As an embodiment of the utility model, the second adhesive layer 6 adopts polyurethane adhesive series, and the thickness of the second adhesive layer 6 is 3 μm~6 μm.

[0042] The polyurethane adhesive is composed of two components of main agent and curing agent, wherein the main agent can be one of polyester polyol and polyether polyol, and the curing agent selects aliphatic isocyanate or aromatic ring isocyanate.

[0043] As an embodiment of the utility model, the metal foil layer is aluminum foil layer 2 or steel foil layer 3, and the thickness is 30 μm~150 μm. When the aluminum foil is used, the aluminum foil is preferably 8021 or 8079 series, and the ductility is high, which is beneficial to deep drawing forming. When the metal foil layer adopts the aluminum foil layer 2, the embodiment is as shown in Figure 1 ; when the metal foil layer adopts the steel foil layer 3, the embodiment is as shown in Figure 2 .

[0044] As an embodiment of the utility model, the thickness of the inner layer 4 is 25 μm~100 μm. The inner layer 4 PCTFE layer surface needs to be treated by corona.

[0045] Embodiment 2

[0046] As shown in Figure 3 and Figure 4 , it is a second embodiment of the packaging film for solid-state battery packaging of the utility model, and the embodiment is similar to embodiment 1, and the difference lies in that it further includes a slip agent layer 8, and the slip agent layer 8 is located on the outer surface of the outer layer.

[0047] When the metal foil layer adopts the aluminum foil layer 2, the embodiment is as shown in Figure 3 ; when the metal foil layer adopts the steel foil layer 3, the embodiment is as shown in Figure 4 .

[0048] The outer surface of the outer layer of the packaging film is coated with a slip agent layer 8. The addition of the slip agent layer 8 can obtain a packaging film with low friction coefficient and improve the high drawability of the packaging film. The slip agent layer 8 is selected from any one or a combination of oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis-stearamide and ethylene bis-oleic acid amide. The concentration of the slip agent ranges from 0.05% to 0.5%.

[0049] Embodiment 3

[0050] As shown in Figure 5 and Figure 6 shows a third embodiment of the packaging film for solid-state battery packaging, which is similar to the first embodiment, and the difference is that the outer layer comprises a thermoplastic polyester layer 7 and a polyamide material layer 1 arranged in sequence, and a third adhesive layer 9 is arranged between the thermoplastic polyester layer 7 and the polyamide material layer 1.

[0051] Preferably, the polyamide material layer 1 is a nylon layer, and the thermoplastic polyester layer 7 is a polyethylene terephthalate layer.

[0052] When the metal foil layer is an aluminum foil layer 2, the embodiment is as shown in Figure 5 ; when the metal foil layer is a steel foil layer 3, the embodiment is as shown in Figure 6 .

[0053] The material of the thermoplastic polyester layer 7 is any one of polyethylene terephthalate or polybutylene terephthalate. The polyethylene terephthalate or polybutylene terephthalate layer has excellent physical and mechanical properties in a wide temperature range, and the long-term use temperature can reach 120℃, and has excellent electrical insulation, even at high temperature and high frequency, the electrical properties are still good, and the creep resistance, fatigue resistance, friction resistance and dimensional stability are very good. The outer layer of the packaging film can be a single layer of a nylon layer, or can be composed of a nylon layer and a thermoplastic polyester layer 7, and the overall thickness of the outer layer is 15μm~40μm, and the thickness of the single thermoplastic polyester layer 7 can be 2μm~15μm. The polyester layer needs to be subjected to corona treatment.

[0054] As an embodiment of the present application, the nylon layer and the thermoplastic polyester layer 7 are bonded by a third adhesive layer 7. The third adhesive layer 7 is a polyurethane adhesive, and the thickness of the third adhesive layer 7 is 3μm~6μm. The nylon layer and the thermoplastic polyester layer 7 are bonded by a polyurethane adhesive, and the first adhesive layer 5 between the nylon layer and the metal foil layer is also a polyurethane adhesive; of course, within the scope of cognition of those skilled in the art, the nylon layer and the thermoplastic polyester layer 7 can also be bonded by other adhesives.

[0055] Embodiment 4

[0056] As shown in Figure 7 and Figure 8The fourth embodiment of the packaging film for solid-state battery packaging is shown, the embodiment is similar to the embodiment 2, the difference is that the outer layer comprises the thermoplastic polyester layer 7 and the polyamide material layer 1 arranged in sequence, and the third adhesive layer 9 is arranged between the thermoplastic polyester layer 7 and the polyamide material layer 1.

[0057] Preferably, the polyamide material layer 1 is nylon 6 or nylon 66, and the thermoplastic polyester layer 7 is polyethylene terephthalate.

[0058] The embodiment is improved based on the embodiment 2, and the slip agent layer 8 is additionally arranged; when the metal foil layer is the aluminum foil layer 2, the embodiment is as shown in the figure; Figure 7 When the metal foil layer is the steel foil layer 8, the embodiment is as shown in the figure. Figure 6

[0059] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not the limitation to the embodiments of the utility model. For the ordinary skilled in the art, other different forms of changes or changes can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement, etc. made in the spirit and principle of the utility model should be included in the protection scope of the utility model claims.​

Claims

1. A packaging film for solid-state battery packaging, comprising, in order from the outside, an outer layer, a metal foil layer, and an inner layer (4), characterized in that, The inner layer (4) is a fluoroplastic layer; the outer layer is a polyamide material layer (1), a first adhesive layer (5) is arranged between the polyamide material layer (1) and the metal foil layer; a second adhesive layer (6) is arranged between the metal foil layer and the inner layer (4).

2. The packaging film for solid-state battery packaging according to claim 1, characterized by, The material of the fluoroplastic layer is any one of polytrifluorochloroethylene, perfluoroethylene propylene copolymer, polyvinylidene chloride or polyvinyl fluoride.

3. The packaging film for solid-state battery packaging according to claim 1 or 2, characterized by, A slip agent layer (8) is further included, and the slip agent layer (8) is located on the outer surface of the outer layer.

4. The packaging film for solid-state battery packaging according to claim 3, characterized by, The material of the slip agent layer (8) is one of oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis-stearamide or ethylene bis-oleic acid amide.

5. The packaging film for solid-state battery packaging according to claim 1, wherein The outer layer comprises a thermoplastic polyester layer (7) and a polyamide material layer (1) arranged in sequence, and a third adhesive layer (9) is arranged between the thermoplastic polyester layer (7) and the polyamide material layer (1).

6. The packaging film for solid-state battery packaging according to claim 5, wherein The material of the polyamide material layer (1) is nylon 6 or nylon 66.

7. The packaging film for solid-state battery packaging according to claim 5, wherein The material of the thermoplastic polyester layer (7) is polyethylene terephthalate or polybutylene terephthalate.

8. The packaging film for solid-state battery packaging according to claim 1, wherein The metal foil layer is an aluminum foil layer (2) or a steel foil layer (3).

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