Aluminum-plastic film with high thermal conductivity and high punching performance, preparation method thereof and lithium ion battery

Abstract

The application belongs to the technical field of lithium battery aluminum plastic film, and particularly relates to an aluminum plastic film with high heat conductivity and high punching performance, a preparation method thereof and a lithium ion battery, which comprises, from outside to inside, a nylon film layer, a glue layer, an aluminum foil layer and a CPP film layer which are stacked and combined in sequence; the glue layer is made of AB two-component polyurethane glue; the A component comprises the following components in mass fraction: polyester polyol 20-35 parts, polyether polyol 15-25 parts, polyisocyanate monomer 5-10 parts, silane coupling agent 1-5 parts, graphene oxide 1-5 parts and solvent 40-60 parts; the B component comprises the following components in mass fraction: polyisocyanate curing agent 95-99 parts and solvent 1-5 parts; the CPP film layer comprises, from the aluminum foil layer to outside, a corona layer, a support layer and a heat sealing layer, and all contain BN inorganic particles; the application adds boron nitride inorganic particles which are high-heat-conducting materials into the material of the CPP film to change the crystallization nucleation rate of the CPP film, and cooperates with the graphene oxide in the glue layer to obtain excellent punching performance.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery aluminum-plastic film technology, specifically relating to an aluminum-plastic film with high thermal conductivity and high drawing depth performance, its preparation method, and a lithium-ion battery. Background Technology

[0002] With the rapid development of the soft-pack lithium-ion battery application industry, higher performance requirements have been placed on aluminum-plastic films. Lithium batteries release heat during charging and discharging. In summer, most electric vehicles are charged under direct sunlight, and when the battery is charged and discharged at high temperatures, the positive and negative electrodes react with the electrolyte, releasing additional heat. If this large amount of heat cannot be dissipated in time, it can easily cause the separator to melt, leading to a fire. This necessitates high thermal conductivity for soft-pack lithium batteries.

[0003] To overcome the defect of insufficient thermal conductivity, existing aluminum-plastic films often incorporate high thermal conductivity materials for auxiliary heat dissipation, but this introduces new defects such as insufficient drawing depth performance.

[0004] Therefore, how to solve the problem of the inability to simultaneously achieve thermal conductivity and deep-drawing performance of aluminum-plastic film is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0006] This disclosure provides at least one aluminum-plastic film with high thermal conductivity and high drawing depth performance, a method for preparing the same, and a lithium-ion battery.

[0007] In a first aspect, embodiments of this disclosure provide an aluminum-plastic film with high thermal conductivity and high drawing depth performance, comprising: a nylon film layer, an adhesive layer, an aluminum foil layer, and a CPP film layer stacked sequentially from the outside to the inside; wherein the adhesive layer is made of a two-component polyurethane adhesive; the A component comprises the following components in parts by weight: 20-35 parts of polyester polyol, 15-25 parts of polyether polyol, 5-10 parts of polyisocyanate monomer, 1-5 parts of silane coupling agent, 1-5 parts of graphene oxide, and 40-60 parts of solvent; the B component comprises the following components in parts by weight: 95-99 parts of polyisocyanate curing agent and 1-5 parts of solvent; the CPP film layer, from the aluminum foil layer outwards, comprises a corona layer, a support layer, and a heat-sealing layer, all of which contain BN inorganic particles.

[0008] In one optional embodiment, the corona layer comprises the following components in parts by weight, with a total of 100 parts: 50-60 parts of MPP resin, 30-40 parts of homopolymer polypropylene resin, 1-5 parts of slip masterbatch, and 1-5 parts of BN inorganic particles.

[0009] In one optional embodiment, the support layer comprises the following components in parts by weight, with a total of 100 parts: 85-95 parts homopolymer polypropylene resin, 1-5 parts slip masterbatch, and 1-5 parts BN inorganic particles.

[0010] In one optional embodiment, the heat-sealing layer comprises the following components in parts by weight, with a total of 100 parts: 80-90 parts of ternary copolymer polypropylene resin, 2-8 parts of hyperbranched amide resin, 1-5 parts of slip masterbatch, and 1-5 parts of BN inorganic particles.

[0011] In one optional embodiment, the mass ratio of component A to component B is 100:

[0012] (20-32).

[0013] In one optional embodiment, the thickness of the nylon film layer ranges from 15 to 25 μm; the thickness of the adhesive layer ranges from 3 to 5 μm; the thickness of the aluminum foil layer ranges from 35 to 55 μm; the thickness of the CPP film layer ranges from 40 to 60 μm; wherein the thickness ratio of the corona layer, the support layer, and the heat-sealing layer in the CPP film layer is 1:2:2.

[0014] In one optional embodiment, the particle size of the BN inorganic particles is 100-150 μm.

[0015] In one alternative embodiment, the thickness of the graphene oxide sheet is 80-120 nm.

[0016] Secondly, this disclosure also provides a method for preparing an aluminum-plastic film with high thermal conductivity and high drawing depth performance as described above, comprising the following steps: Step S1, mixing various raw materials evenly in proportion and then metering them cleanly; Step S2, using programmed temperature control, setting the temperature of the melt extruder, filter, and transmission pipeline to 220-240℃, and the temperature of the distributor and T-die to 240℃, to obtain the filtered melt; Step S3, passing the filtered melt through the T-die and then through a non-mirror casting process... After cooling and crystallization, the film is shaped and formed, with a casting speed of 40-60 m / min, to obtain a pre-prepared CPP film layer; in step S4, the thickness of the pre-prepared CPP film layer is measured and adjusted, and the surface is treated with ozone corona to form a corona layer, which is then drawn and wound into a film to obtain the CPP film layer; in step S5, an acid-resistant agent is coated on both sides of the aluminum foil to form an acid-resistant film, to obtain the aluminum foil layer; in step S6, the bright side of the treated aluminum foil layer is hot-pressed with the CPP film corona layer, with a pressure of 0.3-0.5 mm. MPa, pressing temperature of 160-180℃, oven temperature of 200-220℃, speed of 30-40m / min, to obtain a semi-finished aluminum foil layer; Step S7, polyester polyol and polyether polyol are added to the reaction vessel, heated to 120℃-130℃, stirred under vacuum for 2-3 hours, cooled to 40℃, and then polyisocyanate monomer, silane coupling agent, graphene oxide and solvent are added to the reaction vessel in sequence, heated to 90-110℃, stirred under vacuum for 3-6 hours, to obtain Component A; Component B, consisting of polyisocyanate curing agent and solvent, is added to component A and vacuum stirred for 1 hour to obtain polyurethane adhesive; Step S8, the matte surface of the semi-finished aluminum foil layer from step S6 is coated and bonded to the nylon film using the polyurethane adhesive from step S7. The adhesive thickness is 3-5 μm, the pressure is 0.3-0.5 MPa, the bonding temperature is 60-70℃, the oven temperature is 70-90℃, and the speed is 60-80 m / min to obtain an aluminum-plastic film with high thermal conductivity and high drawing depth performance.

[0017] Thirdly, embodiments of this disclosure also provide a lithium-ion battery, comprising an aluminum-plastic film with high thermal conductivity and high drawing depth performance as described above.

[0018] The beneficial effects of this invention are as follows: the high thermal conductivity and high drawing depth performance aluminum-plastic film and its preparation method, and the addition of high thermal conductivity boron nitride inorganic particles to the CPP film material of lithium-ion batteries to change the crystallization nucleation rate of the CPP film, thereby enhancing the thermal conductivity of the CPP film so that heat can be quickly conducted to the outside of the battery, and improving the orderly arrangement of molecules in the CPP film. Combined with the ductility and thermal conductivity of graphene oxide in the adhesive layer, the overall thermal conductivity of the aluminum-plastic film is improved and stress can be evenly distributed during punching, resulting in excellent drawing depth performance.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an aluminum-plastic film with high thermal conductivity and high drawing depth performance provided in an embodiment of this disclosure.

[0023] In the picture:

[0024] 1. Nylon film layer; 2. Adhesive layer; 3. Aluminum foil layer; 41. Corona layer; 42. Support layer; 43. Heat-sealing layer. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0027] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0028] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0029] Aluminum-plastic film is the main packaging material for soft-pack lithium batteries. It is mainly composed of four layers: a nylon film layer, an adhesive layer, an aluminum foil layer, and a CPP film layer, from the outside to the inside. The CPP film is in direct contact with the electrolyte and is crucial for heat dissipation. Meanwhile, the adhesive layer also plays an important role in heat conduction.

[0030] Specifically, CPP film refers to cast polypropylene film, MPP resin refers to polymers made by polymerization of propylene or copolymerization of propylene with one or more other unsaturated compounds, and BN inorganic particles refer to boron nitride inorganic particles.

[0031] Therefore, simply improving the CPP film layer in the existing process cannot completely solve the thermal conductivity problem of aluminum-plastic film.

[0032] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure below should be considered as the inventor's contribution to this disclosure.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] Please see Figure 1 ,like Figure 1 As shown, this disclosure provides an aluminum-plastic film with high thermal conductivity and high drawing depth performance, comprising: a nylon film layer, an adhesive layer, an aluminum foil layer, and a CPP film layer stacked sequentially from the outside to the inside; wherein the adhesive layer is made of a two-component polyurethane adhesive; the A component comprises the following components in parts by weight: 20-35 parts polyester polyol, 15-25 parts polyether polyol, 5-10 parts polyisocyanate monomer, 1-5 parts silane coupling agent, 1-5 parts graphene oxide, and 40-60 parts solvent; the B component comprises the following components in parts by weight: 95-99 parts polyisocyanate curing agent and 1-5 parts solvent; the CPP film layer, from the aluminum foil layer outwards, consists of a corona layer, a support layer, and a heat-sealing layer, all of which contain BN inorganic particles.

[0036] In some embodiments, the corona layer specifically comprises the following components in parts by weight, with a total weight of 100 parts: 50-60 parts MPP resin, 30-40 parts homopolymer polypropylene resin, 1-5 parts slip masterbatch, and 1-5 parts BN inorganic particles. Through corona treatment, the corona layer can firmly adhere to the glossy surface of the aluminum foil, significantly improving its resistance to electrolytes, thus greatly enhancing the corrosion resistance of the CPP film.

[0037] In some embodiments, the support layer specifically comprises the following components in parts by weight, with a total weight of 100 parts: 85-95 parts homopolymer polypropylene resin, 1-5 parts slip masterbatch, and 1-5 parts BN inorganic particles. The support layer occupies a central position in the CPP film, serving a crucial role in supporting the stable structure of the CPP film, preventing deformation, and ensuring that the corona layer and heat-sealing layer do not interfere with each other.

[0038] In some embodiments, the heat-sealing layer specifically comprises the following components in parts by weight, with a total of 100 parts: 80-90 parts of ternary copolymer polypropylene resin, 2-8 parts of hyperbranched amide resin, 1-5 parts of slip masterbatch, and 1-5 parts of BN inorganic particles. The heat-sealing layer determines the overall heat-sealing strength of the aluminum-plastic film, and its strength directly determines whether electrolyte leakage will occur after the aluminum-plastic film is heat-sealed.

[0039] In some embodiments, specifically, the mass ratio of component A to component B is 100:

[0040] (20-32).

[0041] In some embodiments, specifically, the thickness of the nylon film layer ranges from 15 to 25 μm; the thickness of the adhesive layer ranges from 3 to 5 μm; the thickness of the aluminum foil layer ranges from 35 to 55 μm; the thickness of the CPP film layer ranges from 40 to 60 μm; wherein the thickness ratio of the corona layer, the support layer, and the heat-sealing layer in the CPP film layer is 1:2:2.

[0042] In some embodiments, specifically, the particle size of the BN inorganic particles is 100-150 μm, preferably 120 μm.

[0043] In some embodiments, specifically, the thickness of the graphene oxide sheet is 80-120 nm, preferably 100 nm.

[0044] This disclosure also provides a method for preparing an aluminum-plastic film with high thermal conductivity and high drawing depth as described above, comprising the following steps: Step S1, mixing various raw materials evenly in proportion and then metering them cleanly; Step S2, using programmed temperature control, setting the temperature of the melt extruder, filter, and transmission pipeline to 220-240℃, and the temperature of the distributor and T-die to 240℃, to obtain a filtered melt; Step S3, passing the filtered melt through a T-die and then through a non-mirror casting process, followed by cooling and solidification. Step S4: The pre-prepared CPP film layer is obtained by casting at a speed of 40-60 m / min; Step S5: The thickness of the pre-prepared CPP film layer is measured and adjusted, and the surface is treated with ozone corona to form a corona layer. The film is then drawn and wound into a CPP film layer; Step S6: An acid-resistant agent is coated on both sides of the aluminum foil to form an acid-resistant film, resulting in an aluminum foil layer; Step S7: The bright side of the treated aluminum foil layer is hot-pressed onto the CPP film corona layer at a pressure of 0.3-0.5 MPa. The pressing temperature is 160-180℃, the oven temperature is 200-220℃, and the speed is 30-40m / min to obtain a semi-finished aluminum foil layer; in step S7, polyester polyol and polyether polyol are added to the reaction vessel, heated to 120℃-130℃, and stirred under vacuum for 2-3 hours. After cooling to 40℃, polyisocyanate monomer, silane coupling agent, graphene oxide, and solvent are added to the reaction vessel in sequence, heated to 90-110℃, and stirred under vacuum for 3-6 hours to obtain the component. A; Add component B, consisting of polyisocyanate curing agent and solvent, to component A, and stir under vacuum for 1 hour to obtain polyurethane adhesive; Step S8, coat and bond the matte surface of the semi-finished aluminum foil layer from step S6 to the nylon film using the polyurethane adhesive from step S7. The adhesive thickness is 3-5 μm, the pressure is 0.3-0.5 MPa, the bonding temperature is 60-70℃, the oven temperature is 70-90℃, and the speed is 60-80 m / min to obtain an aluminum-plastic film with high thermal conductivity and high drawing depth performance.

[0045] Specifically, in step S6, hot pressing is used to firmly bond the MPP resin to the aluminum foil, resisting electrolyte corrosion.

[0046] This disclosure also provides a lithium-ion battery comprising an aluminum-plastic film with high thermal conductivity and high drawing depth performance as described above.

[0047] The performance of the aluminum-plastic film provided by this invention was tested according to the following method:

[0048] (1) Heat sealing strength

[0049] Using a Japanese Tester Sangyo TP-701-B heat sealer, two 10cm*10cm aluminum-plastic films were aligned and heat-sealed at a heat-sealing temperature of 190℃, a pressure of 0.5MPa, and a heat-sealing time of 3s. After the samples cooled to room temperature, the heat seal strength was tested using a Shimadzu AGS-X series electronic universal testing machine.

[0050] (2) Deep scour to form a pit

[0051] Use a shell punching machine to punch a pit. Start punching from 5.0mm and punch 10 samples consecutively. If there is no delamination, cracks, or pinholes when inspected under strong light, increase the pit by 0.3mm and continue punching 10 more samples until the shell breaks. Record the punching depth before the shell breaks, which is the limit punching depth.

[0052] (3) Determination of thermal conductivity of aluminum-plastic film

[0053] First, the density of the prepared composite material was tested using a ZMD-1 density balance, following the method in GB / T6343-95. Then, a differential scanning calorimeter was used to calculate the specific heat of the unknown sample by comparing the measurement results of a standard sample (alumina) with a sample of unknown specific heat. Finally, a laser thermal conductivity meter (NETZSCH LFA447, Germany) was used to determine the thermal diffusivity of the sample, according to ASTM E1461. The thermal conductivity of the sample was then calculated using the measured density and specific heat.

[0054] Example 1

[0055] This embodiment provides an aluminum-plastic film with high thermal conductivity and high drawing depth performance, and its preparation method.

[0056] A 45µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0057] The corona layer resin was obtained by uniformly mixing 55 parts of MPP resin, 40 parts of homopolymer polypropylene resin V30G, 4 parts of slip masterbatch C8203ZH, and 1 part of BN inorganic particles.

[0058] The supporting layer resin is obtained by uniformly mixing 95 parts of homopolymer polypropylene resin V30G, 4 parts of slip masterbatch C8203ZH, and 1 part of BN inorganic particles.

[0059] The heat-sealing resin is obtained by uniformly mixing 90 parts of ternary copolymer polypropylene resin TF400, 5 parts of hyperbranched amide resin, 4 parts of slip masterbatch C8203ZH, and 1 part of BN inorganic particles.

[0060] The raw materials after the above-mentioned layer mixing treatment are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruder, filter, conveying pipeline, distributor, and T-die for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then subjected to corona discharge at a power of 30 W / (m). 2 The corona layer surface was corona treated under conditions of ( / min), and then pulled and wound into a film. The film thickness was 50 μm.

[0061] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. After traction and winding, it is ready for use.

[0062] Add 25 parts of polyester polyol and 15 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 5 parts of polyisocyanate monomer, 4 parts of silane coupling agent, 1 part of graphene oxide and 50 parts of solvent to the reactor, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, consisting of 99 parts of polyisocyanate curing agent and 1 part of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0063] The matte surface of the aluminum foil in the CPP semi-finished product is coated and bonded to a 15µm nylon film using the polyurethane adhesive described above, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0064] Example 2

[0065] The aluminum-plastic film with high thermal conductivity and high drawing depth performance, as provided in Example 1, and its preparation method.

[0066] A 40µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0067] The corona layer resin was obtained by uniformly mixing 55 parts of MPP resin, 40 parts of homopolymer polypropylene resin V30G, 2 parts of slip masterbatch C8203ZH, and 3 parts of BN inorganic particles.

[0068] The support layer resin is obtained by uniformly mixing 95 parts of homopolymer polypropylene resin V30G, 2 parts of slip masterbatch C8203ZH, and 3 parts of BN inorganic particles.

[0069] The heat-sealing resin is obtained by uniformly mixing 90 parts of ternary copolymer polypropylene resin TF400, 5 parts of hyperbranched amide resin, 2 parts of slip masterbatch C8203ZH, and 3 parts of BN inorganic particles.

[0070] The raw materials after the above-mentioned layer mixing treatment are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruder, filter, conveying pipeline, distributor, and T-die for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then subjected to corona discharge at a power of 30 W / (m). 2 The corona layer surface was corona treated under conditions of ( / min), and then pulled and wound into a film. The film thickness was 55 μm.

[0071] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. After traction and winding, it is ready for use.

[0072] Add 30 parts of polyester polyol and 19 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 6 parts of polyisocyanate monomer, 3 parts of silane coupling agent, 2 parts of graphene oxide and 40 parts of solvent to the reactor, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, consisting of 98 parts of polyisocyanate curing agent and 2 parts of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0073] The matte surface of the aluminum foil in the CPP semi-finished product is coated and bonded to a 15µm nylon film using the polyurethane adhesive described above, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0074] Example 3

[0075] The aluminum-plastic film with high thermal conductivity and high drawing depth performance, as provided in Example 1, and its preparation method.

[0076] A 35µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0077] The corona layer resin was obtained by uniformly mixing 60 parts of MPP resin, 35 parts of homopolymer polypropylene resin V30G, 2 parts of slip masterbatch C8203ZH, and 3 parts of BN inorganic particles.

[0078] The support layer resin is obtained by uniformly mixing 95 parts of homopolymer polypropylene resin V30G, 2 parts of slip masterbatch C8203ZH, and 3 parts of BN inorganic particles.

[0079] Two parts of ternary copolymer polypropylene resin TF4009, three parts of hyperbranched amide resin, two parts of slip masterbatch C8203ZH, and three parts of BN inorganic particles were uniformly mixed to obtain the heat-sealing layer resin.

[0080] The raw materials after the above-mentioned layer mixing treatment are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruder, filter, conveying pipeline, distributor, and T-die for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then subjected to corona discharge at a power of 30 W / (m). 2 The corona layer surface was corona treated under conditions of ( / min), and then pulled and wound into a film. The film thickness was 50 μm.

[0081] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. The foil is then pulled and wound up for later use.

[0082] Add 30 parts of polyester polyol and 19 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 5 parts of polyisocyanate monomer, 2 parts of silane coupling agent, 4 parts of graphene oxide and 40 parts of solvent to the reactor, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, consisting of 96 parts of polyisocyanate curing agent and 4 parts of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0083] The matte aluminum foil from the CPP semi-finished product is coated and bonded to a 25µm nylon film using the aforementioned polyurethane adhesive, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0084] Example 4

[0085] The aluminum-plastic film with high thermal conductivity and high drawing depth performance, as provided in Example 1, and its preparation method.

[0086] A 40µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0087] The corona layer resin was obtained by uniformly mixing 60 parts of MPP resin, 30 parts of homopolymer polypropylene resin V30G, 5 parts of slip masterbatch C8203ZH, and 5 parts of BN inorganic particles.

[0088] The support layer resin is obtained by uniformly mixing 90 parts of homopolymer polypropylene resin V30G, 5 parts of slip masterbatch C8203ZH, and 5 parts of BN inorganic particles.

[0089] Five parts of ternary copolymer polypropylene resin TF4008, five parts of hyperbranched amide resin, five parts of slip masterbatch C8203ZH, and five parts of BN inorganic particles were uniformly mixed to obtain the heat-sealing layer resin.

[0090] The raw materials, after being mixed in the above-mentioned layers, are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruders, filters, transmission pipelines, distributors, and T-die heads for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die head in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then the surface of the corona layer is corona-treated at a corona power of 30 W / (m² / min). The film is then pulled and wound into a film with a thickness of 50 μm.

[0091] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. The foil is then pulled and wound up for later use.

[0092] Add 29 parts of polyester polyol and 18 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 5 parts of polyisocyanate monomer, 1 part of silane coupling agent, 5 parts of graphene oxide and 42 parts of solvent to the reactor, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, consisting of 96 parts of polyisocyanate curing agent and 4 parts of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0093] The matte surface of the aluminum foil in the CPP semi-finished product is coated and bonded to a 20µm nylon film using the aforementioned polyurethane adhesive, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0094] Comparative Example 1

[0095] This invention provides an aluminum-plastic film with good thermal conductivity and its preparation method.

[0096] A 40µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0097] The corona layer resin is obtained by uniformly mixing 60 parts of MPP resin, 35 parts of homopolymer polypropylene resin V30G, and 5 parts of slip masterbatch C8203ZH.

[0098] The support layer resin is obtained by uniformly mixing 95 parts of homopolymer polypropylene resin V30G and 5 parts of slip masterbatch C8203ZH.

[0099] The heat-sealing resin is obtained by uniformly mixing 90 parts of ternary copolymer polypropylene resin TF400, 5 parts of hyperbranched amide resin, and 5 parts of slip masterbatch C8203ZH.

[0100] The raw materials after the above-mentioned layer mixing treatment are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruder, filter, conveying pipeline, distributor, and T-die for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then subjected to corona discharge at a power of 30 W / (m). 2 The corona layer surface was corona treated under conditions of ( / min), and then pulled and wound into a film. The film thickness was 50 μm.

[0101] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. The foil is then pulled and wound up for later use.

[0102] Add 25 parts of polyester polyol and 15 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 5 parts of polyisocyanate monomer, 5 parts of silane coupling agent and 50 parts of solvent to the reactor in sequence, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, which consists of 95 parts of polyisocyanate curing agent and 5 parts of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0103] The matte surface of the aluminum foil in the CPP semi-finished product is coated and bonded to a 20µm nylon film using the aforementioned polyurethane adhesive, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0104] Comparative Example 2

[0105] An aluminum-plastic film and its preparation method are provided.

[0106] A 40µm thick aluminum foil is coated on both sides with passivation solution to form an acid-resistant film. It is then dried in an oven at 240-280℃ and wound up for later use.

[0107] The corona layer resin is obtained by uniformly mixing 60 parts of MPP resin, 35 parts of homopolymer polypropylene resin V30G, and 5 parts of slip masterbatch C8203ZH.

[0108] The support layer resin is obtained by uniformly mixing 95 parts of homopolymer polypropylene resin V30G and 5 parts of slip masterbatch C8203ZH.

[0109] The heat-sealing resin is obtained by uniformly mixing 90 parts of ternary copolymer polypropylene resin TF400, 5 parts of hyperbranched amide resin, and 5 parts of slip masterbatch C8203ZH.

[0110] The raw materials after the above-mentioned layer mixing treatment are fed into a metering hopper and mixed in proportion. Then, they are fed into the corresponding extruder, filter, conveying pipeline, distributor, and T-die for pressurized melting and plasticizing at a temperature of 240℃. The mixture is then co-extruded through the T-die in three layers at a casting speed of 50 m / min, and cooled to crystallize into a film. The thickness of the resulting film is measured, and then subjected to corona discharge at a power of 30 W / (m). 2 The corona layer surface was corona treated under conditions of ( / min), and then pulled and wound into a film. The film thickness was 55 μm.

[0111] The passivated aluminum foil glossy surface is hot-pressed onto the CPP film corona layer at a pressure of 0.4 MPa, a pressing temperature of 170℃, an oven temperature of 220℃, and a speed of 30 m / min. The foil is then pulled and wound up for later use.

[0112] Add 30 parts of polyester polyol and 19 parts of polyether polyol to a reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add 5 parts of polyisocyanate monomer, 2 parts of silane coupling agent, 4 parts of graphene oxide and 40 parts of solvent to the reactor, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, consisting of 96 parts of polyisocyanate curing agent and 4 parts of solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive.

[0113] The matte surface of the aluminum foil in the CPP semi-finished product is coated and bonded to a 20µm nylon film using the aforementioned polyurethane adhesive, with an adhesive thickness of 3µm. The bonding process is carried out at a pressure of 0.4MPa, a bonding temperature of 70℃, an oven temperature of 80℃, and a speed of 60m / min to obtain the final product.

[0114] Compared with the technical solution provided by this invention, Comparative Example 1 differs in that BN inorganic particles are not added to the CPP formulation and graphene oxide is not added to the polyurethane adhesive in the adhesive layer; Comparative Example 2 differs in that BN inorganic particles are not added to the CPP formulation and 4 parts of graphene oxide are added to the polyurethane adhesive in the adhesive layer.

[0115] Specifically, the performance test results of Examples 1-4 and Comparative Examples 1-2 are shown in Table 1 below.

[0116] Table 1

[0117]

[0118]

[0119] Specifically, in Comparative Example 1, the thermal conductivity was significantly reduced compared to the examples where no BN inorganic particles were added. In Comparative Example 2, although no BN inorganic particles were added compared to Comparative Example 1, graphene oxide was added to the polyurethane adhesive, which improved both the thermal conductivity and drawing performance to a certain extent. However, the effect was still far lower than that of Examples 1-4, where both were added simultaneously.

[0120] In summary, this high thermal conductivity and high drawing depth performance aluminum-plastic film and its preparation method, and the addition of high thermal conductivity boron nitride inorganic particles to the CPP film material of lithium-ion batteries to change the crystallization nucleation rate of the CPP film, thereby enhancing the thermal conductivity of the CPP film so that heat can be quickly conducted to the outside of the battery, and improving the orderly arrangement of molecules in the CPP film. Combined with the ductility and thermal conductivity of graphene oxide in the adhesive layer, the overall thermal conductivity of the aluminum-plastic film is improved and stress can be evenly distributed during punching, resulting in excellent drawing depth performance.

[0121] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high thermal conductivity and high drawing depth performance aluminum-plastic film, characterized in that, include: The layers are stacked sequentially from the outside in: a nylon film layer, an adhesive layer, an aluminum foil layer, and a CPP film layer; among which... The adhesive layer is made of AB two-component polyurethane adhesive; Component A comprises the following components in parts by mass: 20-35 parts polyester polyol, 15-25 parts polyether polyol, 5-10 parts polyisocyanate monomer, 1-5 parts silane coupling agent, 1-5 parts graphene oxide and 40-60 parts solvent. Component B comprises the following components in parts by mass: 95-99 parts of polyisocyanate curing agent and 1-5 parts of solvent; The CPP film layer consists of a corona layer, a support layer, and a heat-sealing layer from the aluminum foil layer inwards, and all of them contain BN inorganic particles. The corona layer comprises the following components in parts by mass, with a total of 100 parts: 50-60 parts of MPP resin, 30-40 parts of homopolymer polypropylene resin, 1-5 parts of slip masterbatch and 1-5 parts of BN inorganic particles. The support layer comprises the following components in parts by mass, and the total number of parts is 100: 85-95 parts homopolymer polypropylene resin, 1-5 parts slip masterbatch and 1-5 parts BN inorganic particles; The heat-sealing layer comprises the following components in parts by weight, and the total number of parts is 100: The mixture consists of 80-90 parts of ternary copolymer polypropylene resin, 2-8 parts of hyperbranched amide resin, 1-5 parts of slip masterbatch, and 1-5 parts of BN inorganic particles.

2. The aluminum-plastic film with high thermal conductivity and high drawing depth performance as described in claim 1, characterized in that: The mass ratio of component A to component B is 100:(20-32).

3. The aluminum-plastic film with high thermal conductivity and high drawing depth performance as described in claim 1, characterized in that: The thickness of the nylon film layer ranges from 15 to 25 μm; The thickness of the adhesive layer ranges from 3 to 5 μm; The thickness of the aluminum foil layer ranges from 35 to 55 μm; The thickness of the CPP film layer ranges from 40 to 60 μm; wherein The thickness ratio of the corona layer, support layer, and heat-sealing layer in the CPP film is 1:2:

2.

4. The aluminum-plastic film with high thermal conductivity and high drawing depth performance as described in claim 1, characterized in that: The thickness of the graphene oxide sheets is 80-120 nm.

5. A method for preparing an aluminum-plastic film with high thermal conductivity and high drawing depth performance as described in any one of claims 1-4, characterized in that, The steps include the following: Step S1: Mix all the raw materials evenly according to the proportions and then cleanly measure and feed them. Step S2: Programmable temperature control, setting the temperature of the melt extruder, filter and transmission pipeline to 220-240℃, and the temperature of the distributor and T-die to 240℃, to obtain the filtered melt; Step S3: The filtered melt is passed through a T-die and then cast on a non-mirror surface, then cooled and crystallized to form a film. The casting speed is 40-60 m / min to obtain a pre-prepared CPP film layer. Step S4: Measure and adjust the thickness of the pre-prepared CPP film layer. After ozone corona treatment, the surface becomes a corona layer. The film is then pulled and wound into a film to obtain the CPP film layer. Step S5: Coat both sides of the aluminum foil with an acid-resistant agent to form an acid-resistant film, thus obtaining an aluminum foil layer; Step S6: The glossy side of the treated aluminum foil layer is hot-pressed with the corona layer of the CPP film. The pressure is 0.3-0.5MPa, the pressing temperature is 160-180℃, the oven temperature is 200-220℃, and the speed is 30-40m / min to obtain a semi-finished aluminum foil layer. Step S7: Add polyester polyol and polyether polyol to the reactor, heat to 120℃-130℃, stir under vacuum for 2-3 hours, cool to 40℃, then add polyisocyanate monomer, silane coupling agent, graphene oxide and solvent to the reactor in sequence, heat to 90-110℃, stir under vacuum for 3-6 hours to obtain component A; add component B, which consists of polyisocyanate curing agent and solvent, to component A, stir under vacuum for 1 hour to obtain polyurethane adhesive; In step S8, the matte surface of the semi-finished aluminum foil layer from step S6 is coated and bonded to the nylon film using the polyurethane adhesive from step S7. The adhesive thickness is 3-5 μm, the pressure is 0.3-0.5 MPa, the bonding temperature is 60-70℃, the oven temperature is 70-90℃, and the speed is 60-80 m / min, to obtain an aluminum-plastic film with high thermal conductivity and high drawing depth performance.

6. A lithium-ion battery, characterized in that, Including the aluminum-plastic film with high thermal conductivity and high drawing depth performance as described in any one of claims 1-4.

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