TPU composite material for new energy battery and preparation method of TPU composite material

Abstract

The invention relates to the field of polyurethane film materials for batteries, and discloses a TPU composite material for a new energy battery and a preparation method of the TPU composite material. A TPU composite material for a new energy battery is composed of a cloth film layer, an adhesive film layer and a TPU film layer, the TPU film layer is prepared by melting and casting TPU hot melt adhesive, and the TPU hot melt adhesive is prepared from the following raw materials in parts by weight: 60-80 parts of polyurethane elastomer, 20-30 parts of a toughening aid, 15-25 parts of a flame retardant, 8-15 parts of a heat conducting agent, 2-4 parts of a lubricant and 1-3 parts of an antioxidant; the toughening auxiliary agent is prepared from a POE (Polyolefin Elastomer), long carbon chain alkyl glycidyl ether, dibutyl itaconate and a vinyl dimethyl terminated dimethyl-methyl trifluoropropyl polysiloxane copolymer. The TPU composite material disclosed by the invention is applied to a new energy battery, has relatively good buffering and damping effects and puncture resistance, and is good in flame retardance and thermal conductivity.

Description

Technical Field

[0001] The present application relates to the field of polyurethane film materials for batteries, and more specifically, it relates to a TPU composite material for new energy batteries and a preparation method thereof. Background Art

[0002] As the power source of new energy vehicles, new energy batteries need to have excellent physical and chemical properties and service life. Due to the limited internal loading space of new energy vehicles, new energy batteries need to be closely arranged and connected to form a battery pack.

[0003] When a new energy vehicle operates under different driving conditions such as high speed, low speed, acceleration, and deceleration, the battery pack will discharge at different rates and generate a large amount of heat. With the accumulation of time and the influence of space, uneven heat accumulation will occur. If the battery pack cannot dissipate heat in time, it will cause the temperature of the battery pack system to be too high or the temperature distribution to be uneven, reducing the charge and discharge cycle efficiency of the battery. In severe cases, it will even lead to thermal runaway, affecting the safety and reliability of the battery. In addition, during the operation of a new energy vehicle, it will also encounter bumpy road conditions, causing the battery pack to be impacted irregularly, easily resulting in punctures and damages to the battery pack, affecting the safety performance and service life of the new energy battery pack.

[0004] To solve the above problems, the structure of new energy batteries is optimized in the prior art, and a protective film is coated on the new energy battery, which plays a good protective role. The protective film is usually a single-layer insulating PVC film or a polyurethane film. Although it has good protection and insulation effects, this type of protective film has poor shock absorption and anti-puncture effects, and also has low thermal conductivity, resulting in low protection efficiency for new energy batteries. Summary of the Invention

[0005] To solve the problem that the protective film applied to new energy batteries in the prior art has poor shock absorption, anti-puncture effects, and low thermal conductivity, thereby reducing the protection efficiency for new energy batteries, the present application provides a TPU composite material for new energy batteries and a preparation method thereof.

[0006] In the first aspect, the present application provides a TPU composite material for new energy batteries, adopting the following technical solution: A TPU composite material for new energy batteries is composed of a cloth film layer, an adhesive film layer, and a TPU film layer. The TPU film layer is prepared by melt casting of TPU hot melt adhesive, and the TPU hot melt adhesive is prepared from the following raw materials in parts by weight: Polyurethane elastomer 60 - 80 parts Toughening aid 20 - 30 parts Flame retardant 15 - 25 parts Thermal conductive agent 8 - 15 parts 2 - 4 parts of lubricant 1 - 3 parts of antioxidant; The toughening aid is composed of POE elastomer, long - chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl - terminated dimethyl - methyltrifluoropropyl polysiloxane copolymer.

[0007] By adopting the above - mentioned technical solution, the TPU composite material of the present application is composed of a cloth film layer, a glue film layer and a TPU film layer. The cloth film layer can improve the mechanical strength and puncture resistance of the TPU composite material. Under the action of the glue film layer, the cloth film layer and the TPU film layer are closely and stably bonded. The TPU film layer has excellent mechanical strength, flame retardancy and flexibility, can effectively absorb and disperse external impact force, and significantly improve the safety of new energy batteries under high - temperature conditions and bumpy road conditions. At the same time, the TPU film layer can effectively conduct and dissipate the heat generated by the battery, avoiding performance degradation or even thermal runaway caused by local overheating.

[0008] In the present application, polyurethane elastomer is used as the thermoplastic elastomer material, compounded with a toughening aid, a flame retardant, a heat - conducting agent, a lubricant and an antioxidant to prepare TPU hot - melt adhesive. The TPU film layer is prepared by hot - melt calendering of the TPU hot - melt adhesive. Polyurethane elastomer has excellent elasticity and mechanical properties, and can provide excellent elasticity for the TPU film layer. The toughening aid is composed of POE elastomer, long - chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl - terminated dimethyl - methyltrifluoropropyl polysiloxane copolymer. POE elastomer has excellent toughness and impact resistance, and can reinforce the properties of polyurethane elastomer. Both long - chain alkyl glycidyl ether and dibutyl itaconate have excellent flexibility, can further produce a good synergistic effect with vinyl dimethyl - terminated dimethyl - methyltrifluoropropyl polysiloxane, and are intertwined and dispersed in the POE elastomer, further improving the temperature resistance and flexibility of the POE elastomer. The prepared POE elastomer can further improve the flexibility and impact resistance of polyurethane elastomer while further improving the dispersion uniformity of the flame retardant and heat - conducting agent in the system, thereby improving the adhesion stability, mechanical strength, heat conductivity and flame retardancy of the prepared TPU film layer, making the TPU composite material prepared in the present application have excellent shock - absorption and buffering effects and puncture resistance, and at the same time have good flame retardancy and heat conductivity.

[0009] Preferably, the toughening aid is prepared from the following raw materials in parts by weight: 120 - 150 parts of POE elastomer 10 - 15 parts of long - chain alkyl glycidyl ether 8 - 12 parts of dibutyl itaconate 5 - 8 parts of vinyl dimethyl terminated dimethyl - methyl trifluoropropyl polysiloxane copolymer; the long - carbon - chain alkyl glycidyl ether is dodecyl glycidyl ether and / or tetradecyl glycidyl ether.

[0010] Preferably, the toughening aid is prepared by the following steps: Melt - extrude and pelletize POE elastomer, long - carbon - chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl terminated dimethyl - methyl trifluoropropyl polysiloxane copolymer to obtain the toughening aid.

[0011] By adopting the above - mentioned technical solution, by optimizing the ratio and dosage of each component in the toughening aid and the preparation process of the toughening aid, the comprehensive properties such as the mechanical strength, flame retardancy and thermal conductivity of the prepared TPU film layer can be further improved.

[0012] Preferably, the flame retardant is composed of melamine cyanurate, ammonium phosphate and magnesium hydroxide in a weight ratio of (0.2 - 0.4):1:(1 - 2).

[0013] By adopting the above - mentioned technical solution, using melamine cyanurate, ammonium phosphate and magnesium hydroxide with a relatively optimal weight ratio as the flame retardant helps to quickly dissipate the heat generated by the battery pack, prevent the risk of battery performance decline or even thermal runaway due to excessive temperature. And it can effectively inhibit the spread of fire during combustion, improving the overall safety of new - energy batteries.

[0014] Preferably, the thermal conductive agent is at least a combination of two of boron nitride, aluminum nitride and silicon carbide.

[0015] By adopting the above - mentioned technical solution, the above - mentioned thermal conductive agent has excellent thermal conductivity and good dispersion compatibility with polyurethane elastomer, and can significantly improve the thermal conductivity of TPU composite materials.

[0016] Preferably, the cloth film layer is any one of nylon cloth and polypropylene fiber cloth.

[0017] By adopting the above - mentioned technical solution, choosing nylon cloth or polypropylene fiber cloth as the cloth film layer can effectively improve the mechanical strength and durability of TPU composite materials, enhancing the puncture - resistance and shock - absorption and buffering effects of TPU composite materials.

[0018] Preferably, the adhesive film layer is a polyurethane adhesive film layer, and the polyurethane adhesive film layer is obtained by curing polyurethane adhesive. The polyurethane adhesive is prepared from the following raw materials in parts by weight: Diisocyanate 30 - 40 parts Polyether diol 8 - 12 parts Polycaprolactone diol 10 - 15 parts Chain extender 5 - 10 parts 0.2 - 0.4 parts of catalyst.

[0019] Preferably, the chain extender is composed of hydroxy polyethyleneglycol acrylamide and castor oil modified polyol with a weight ratio of 1:(2 - 3).

[0020] By adopting the above technical solution, the adhesive film layer of this application is a polyurethane adhesive film. This application uses hydroxy polyethyleneglycol acrylamide and castor oil modified polyol with a relatively optimal weight ratio as the chain extender, introducing amide groups and soft castor oil segments into the polyurethane system, and improving the fitting stability between the cloth film layer and the TPU film layer. At the same time, the selection of the chain extender with a relatively optimal ratio and components further improves the flexibility of the adhesive film layer, and then improves the shock absorption and puncture resistance of the prepared TPU composite material.

[0021] Preferably, the thickness of the adhesive film layer is 5 - 10 μm, and the thickness of the TPU film layer is 20 - 30 μm.

[0022] By adopting the above technical solution, the thickness of the adhesive film layer is controlled within the range of 5 - 10 μm, ensuring good adhesion performance and flexibility of the adhesive film. The thickness of the TPU film layer is controlled within the range of 20 - 30 μm, ensuring sufficient heat conduction performance and shock absorption capacity, helping to quickly dissipate the heat generated by the battery, reducing the performance degradation caused by uneven temperature in the battery pack, and improving the safety and reliability of the battery pack.

[0023] In the second aspect, this application provides a preparation method for a TPU composite material for new energy batteries, adopting the following technical solution: A preparation method for a TPU composite material for new energy batteries includes the following steps: S1. Coating polyurethane glue on the surface of the cloth film layer and drying it to form an adhesive film layer; S2. Melting and casting TPU hot melt adhesive and laminating it on the surface of the adhesive film layer, cooling, and winding it up to obtain a TPU composite material for new energy batteries.

[0024] By adopting the above technical solution, first coating polyurethane glue on the cloth film layer and drying it, and then casting and laminating TPU hot melt adhesive on the adhesive film layer. This preparation process can effectively improve the bonding strength and heat resistance of the TPU composite material, and at the same time ensure good heat conductivity and mechanical properties, improving the safety and service life of new energy batteries.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The TPU composite material for new energy batteries of the present application is composed of a cloth film layer, an adhesive film layer, and a TPU film layer. The TPU film layer uses polyurethane elastomer as the thermoplastic elastomer material, compounded with toughening aids, flame retardants, thermal conductors, lubricants, and antioxidants to prepare TPU hot melt adhesive, which is obtained by hot melt calendering of the TPU hot melt adhesive. The toughening aid is composed of POE elastomer, long-chain alkyl glycidyl ether, dibutyl itaconate, and vinyl dimethyl-terminated dimethyl-methyltrifluoropropyl polysiloxane copolymer. The three have good synergistic effects and are intertwined and dispersed in the POE elastomer to further improve the temperature resistance and flexibility of the POE elastomer. The prepared POE elastomer can further improve the flexibility and impact resistance of the polyurethane elastomer while further enhancing the dispersion uniformity of the flame retardant and thermal conductor in the system, thereby improving the adhesion stability, mechanical strength, thermal conductivity, and flame retardancy of the prepared TPU film layer, making the TPU composite material prepared by the present application have excellent shock absorption and anti-puncture effects, and at the same time have good flame retardancy and thermal conductivity.

[0026] 2. The adhesive film layer of the present application is a polyurethane adhesive film. The present application uses hydroxy polyethylene glycol acrylamide and castor oil-modified polyol with a relatively optimal weight ratio as chain extenders to introduce amide groups and soft castor oil segments into the polyurethane system, improving the adhesion stability between the cloth film layer and the TPU film layer. At the same time, the selection of chain extenders with relatively optimal ratios and components further improves the flexibility of the adhesive film layer, thereby enhancing the shock absorption and anti-puncture performance of the prepared TPU composite material.

[0027] 3. The preparation process of the present application is simple and easy to operate, suitable for industrial continuous production, and can prepare TPU composite materials with stable performance. Specific Embodiments

[0028] The following further elaborates on the present application with reference to examples.

[0029] The following are the sources and specifications of some raw materials of the present application. The raw materials used in the preparation examples and examples of the present application can all be obtained commercially, including but not limited to the raw materials of the following models and manufacturers. Raw materials with the same performance can all be used: 1. Polyurethane elastomer: BASF 1198A, Germany; 2. POE elastomer: Dow 8411; 3. Vinyl dimethyl-terminated dimethyl-methyltrifluoropropyl polysiloxane copolymer: Sischibo Organosilicon, 4. Melamine cyanurate: CAS No. 37640-57-6, Greenlink Chemical, FR-MC25S; 5. Nylon fabric: Specification 210D, gram weight 143g, thickness 18mm, plain weave, Suzhou Wenchangxiang Textile Co., Ltd.; 6. Polyether diol: Polytetramethylene ether glycol, molecular weight 1000 - 2000; 7. Polycaprolactone diol: Molecular weight 2000 - 3000; 8. Hydroxy polyethylene glycol acrylamide: Molecular weight 600 - 800; 9. Castor oil modified polyol: Guangzhou Chubu Chemical Industry, THCM - 1300.

[0030] Preparation examples of toughening aids Preparation example 1 Preparation example 1 discloses a toughening aid, which is prepared by the following steps: 12 kg of POE elastomer, 1.5 kg of dodecyl glycidyl ether as long - chain alkyl glycidyl ether, 0.8 kg of dibutyl itaconate and 0.5 kg of vinyl dimethyl - terminated dimethyl - methyl trifluoropropyl polysiloxane copolymer are melt - extruded using a screw extruder. Control the melt - extrusion temperature as follows: the temperature of zone 1 is 80 °C, the temperature of zone 2 is 80 °C, the temperature of zone 3 is 85 °C, the temperature of zone 4 is 90 °C, the temperature of zone 5 is 85 °C, and the die temperature is 80 °C. After extrusion, it is cooled and pelletized to obtain the toughening aid.

[0031] Preparation examples 2 - 3 The differences between preparation examples 2 - 3 and preparation example 1 are that the raw material dosages and preparation conditions are different. For details, see Table 1 below.

[0032] Table 1 Parameter table of preparation examples 1 - 3 Preparation comparative example 1 The difference between preparation comparative example 1 and preparation example 1 is that dodecyl glycidyl ether is replaced with methyl glycidyl ether in equal amount, and the others are the same as preparation example 1.

[0033] Preparation comparative example 2 The difference between preparation comparative example 2 and preparation example 1 is that dibutyl itaconate is replaced with dodecyl glycidyl ether in equal amount, and the others are the same as preparation example 1.

[0034] Preparation comparative example 3 The difference between preparation comparative example 3 and preparation example 1 is that vinyl dimethyl - terminated dimethyl - methyl trifluoropropyl polysiloxane copolymer is replaced with vinyl triethoxysilane in equal amount, and the others are the same as preparation example 1.

[0035] Preparation examples of TPU hot - melt adhesives Preparation example 4 Preparation Example 4 discloses a TPU hot melt adhesive, which is prepared by the following steps: 6 kg of polyurethane elastomer, 3 kg of toughening aid prepared in Preparation Example 1, 1.5 kg of flame retardant (composed of melamine cyanurate, ammonium phosphate and magnesium hydroxide with a weight ratio of 0.2:1:1), 1.5 kg of thermal conductive agent (composed of boron nitride and aluminum nitride with a weight ratio of 2:1), 0.2 kg of stearic acid as a lubricant, and 0.1 kg of antioxidant (composed of antioxidant 1010 and antioxidant 168 with a weight ratio of 2:1) are added to a screw extruder, and the melting temperature is controlled as follows: the temperature of the first zone is 220 °C, the temperature of the second zone is 225 °C, the temperature of the third zone is 230 °C, the temperature of the fourth zone is 235 °C, the temperature of the fifth zone is 225 °C, and the die head temperature is 220 °C for melt extrusion, cooling, and pelletizing to obtain the TPU hot melt adhesive.

[0036] Preparation Examples 5 - 6 The differences between Preparation Examples 5 - 6 and Preparation Example 1 are that the raw material dosages and preparation conditions are different. See Table 2 below for details.

[0037] Table 2 Parameter Table of Preparation Examples 4 - 6 Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 4 is that the toughening aid is from Preparation Comparative Example 1, and the others are the same as Preparation Example 4.

[0038] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 4 is that the toughening aid is from Preparation Comparative Example 2, and the others are the same as Preparation Example 4.

[0039] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 4 is that the toughening aid is from Preparation Comparative Example 3, and the others are the same as Preparation Example 4.

[0040] Preparation Example 10 The difference between Preparation Example 10 and Preparation Example 4 is that the toughening aid is SBS thermoplastic elastomer, and the SBS thermoplastic elastomer is YH - 815 from Baling Petrochemical, and the others are the same as Preparation Example 4.

[0041] Preparation Examples of Polyurethane Adhesive Preparation Example 11 Preparation Example 11 discloses a polyurethane adhesive, which is prepared by the following steps: 3 kg of isophorone diisocyanate, 0.8 kg of polyether diol, 1 kg of polycaprolactone diol, 0.5 kg of chain extender (composed of butanediol and castor oil-modified polyol with a weight ratio of 1:2), and 0.02 kg of dibutyltin dilaurate as a catalyst were added to a reaction kettle, heated to 80 °C, and reacted for 2 h to obtain a polyurethane adhesive.

[0042] Preparation Example 12-13 The difference between Preparation Example 12-13 and Preparation Example 1 lies in the different raw material dosages and preparation conditions. See Table 3 below for details.

[0043] Table 3 Parameter Table of Preparation Examples 11-13 Preparation Example 14 The difference between Preparation Example 14 and Preparation Example 11 is that the chain extender is composed of hydroxy polyethylene glycol acrylamide and castor oil-modified polyol with a weight ratio of 1:2, and the others are the same as Preparation Example 11.

[0044] Preparation Example 15 The difference between Preparation Example 15 and Preparation Example 11 is that the chain extender is composed of hydroxy polyethylene glycol acrylamide and castor oil-modified polyol with a weight ratio of 1:3, and the others are the same as Preparation Example 11. Examples

[0045] Example 1 Example 1 discloses a TPU composite material for new energy batteries, which is composed of a cloth film layer, a glue film layer, and a TPU film layer. The cloth film layer is any one of nylon cloth and polypropylene fiber cloth. Preferably, the cloth film layer in this Example 1 is nylon cloth. The thickness of the glue film layer is 5 μm, and the thickness of the TPU film layer is 30 μm.

[0046] The TPU composite material for new energy batteries is prepared by the following steps: S1. The polyurethane adhesive prepared in Preparation Example 1 was coated on the surface of the cloth film layer and dried to form a glue film layer with a thickness of 5 μm; S2. The TPU hot melt adhesive prepared in Preparation Example 4 was melted and extruded and cast at a screw speed of 20 r / min to form a TPU film with a thickness of 30 μm and roll-pressed and adhered to the surface of the glue film layer, roll-pressed and cooled, and wound up to obtain a TPU composite material for new energy batteries.

[0047] Examples 2-3 The difference between Examples 2-3 and Example 1 lies in the different preparation process parameters. See Table 4 below for details.

[0048] Table 4 Parameter Table of Examples 1-3 Example 4 The difference between Example 4 and Example 1 is that the polyurethane adhesive is from Preparation Example 14, and the others are the same as those in Example 1.

[0049] Example 5 The difference between Example 5 and Example 1 is that the polyurethane adhesive is from Preparation Example 15, and the others are the same as those in Example 1.

[0050] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the TPU hot melt adhesive is from Preparation Example 7, and the others are the same as those in Example 1.

[0051] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the TPU hot melt adhesive is from Preparation Example 8, and the others are the same as those in Example 1.

[0052] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the TPU hot melt adhesive is from Preparation Example 9, and the others are the same as those in Example 1.

[0053] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the TPU hot melt adhesive is from Preparation Example 10, and the others are the same as those in Example 1.

[0054] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the TPU hot melt adhesive prepared in Preparation Example 4 is melted and extruded and cast at a screw rotation speed of 20 r / min to form a TPU film with a thickness of 30 μm and directly roll-pressed and adhered to the surface of the cloth film layer, roll-pressed and cooled, and wound to obtain a TPU composite material for new energy batteries, and the cloth film layer is nylon cloth.

[0055] Performance detection test The following performance tests were carried out on the TPU composite materials prepared in Examples 1-5 and Comparative Examples 1-5: 1. Puncture strength test: Using a puncture strength tester, apply pressure to the surface of the TPU film layer of the TPU composite material, and test the maximum force when the TPU composite material is punctured, which is recorded as the puncture strength (unit: N / mm), and test and record the test results; 2. Impact resistance test: Referring to the test method in GB / T 8809, test the impact energy (unit: J) of the TPU composite material, and test and record the test results; 3. Flame retardancy test: Referring to the UL-94 vertical burning test, test the flame retardancy grade of the TPU composite material, and test and record the test results; 4. Thermal Conductivity Test: Refer to the test method in ASTM-D5470 to test the thermal conductivity of the TPU composite material (unit: W / (m·K)), and test and record the test results; The following are the performance test data of the TPU composite materials of Examples 1-5 and Comparative Examples 1-5 of this application. For details, see Table 5 below.

[0056] Table 5 Data Sheet of TPU Composite Materials of Examples 1-5 and Comparative Examples 1-5 Combined with Examples 1-3, Examples 4-5, Comparative Example 5 and Table 5, it can be concluded that by using the polyurethane adhesive of this application to prepare the adhesive film layer and bonding the cloth film layer and the TPU film layer, the prepared TPU composite material has good shock absorption and anti-puncture properties. In Examples 4-5, the types and ratios of the chain extender in the polyurethane adhesive were optimized, and the anti-puncture strength and anti-impact energy of the prepared TPU composite material were both improved; in Comparative Example 1, the adhesive film layer was not used, and the cloth film layer and the TPU film layer were directly adhered, and the anti-impact performance and anti-puncture strength of the prepared TPU composite material were both reduced, and the thermal conductivity was also slightly reduced. It may be because without the action of the polyurethane adhesive, the bonding effect between the cloth film layer and the TPU film layer was reduced, thereby reducing the mechanical strength and thermal conductivity of the prepared TPU composite film.

[0057] Combined with Examples 1-3 and Comparative Examples 1-4 and Table 5, it can be concluded that by using the toughening agent prepared from POE elastomer, long-chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl-terminated dimethyl-methyltrifluoropropyl polysiloxane copolymer of this application, compounding with polyurethane elastomer, and compounding with thermal conductive agent and flame retardant, as the TPU The TPU composite material prepared from the film layer has good shock absorption and anti-puncture properties, and also has good thermal conductivity and flame retardancy. In Comparative Examples 1-3, the types and ratios of the toughening agent were changed, and the anti-puncture strength and anti-impact energy of the prepared TPU composite material were reduced, and the thermal conductivity was also reduced. It may be because the flexible interweaving and dispersion performance of the toughening agent and the polyurethane system was reduced, thereby reducing the flexibility and anti-impact performance of the TPU film layer. In Comparative Example 4, the toughening agent was directly replaced with SBS thermoplastic elastomer, and the anti-puncture strength and anti-impact energy of the prepared TPU composite material were reduced, and the flame retardancy and thermal conductivity were also significantly reduced. It may be because the change of the toughening agent affected the dispersion compatibility of the flame retardant and the thermal conductive agent in the system, thereby reducing the mechanical properties, flame retardancy and thermal conductivity of the TPU composite material.

[0058] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A TPU composite material for new energy batteries, characterized in that: It consists of a cloth film layer, an adhesive film layer and a TPU film layer. The TPU film layer is made by melt casting of TPU hot melt adhesive. The TPU hot melt adhesive is made of the following raw materials in parts by weight: Polyurethane elastomer 60-80 parts Toughening agent 20-30 parts Flame retardant 15-25 parts Thermal Conductive Agent 8-15 parts 2-4 parts lubricant 1-3 parts of antioxidants; The toughening aid consists of POE elastomer, long carbon chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl-terminated dimethyl-methyl trifluoropropyl polysiloxane copolymer.

2. A TPU composite material for new energy batteries according to claim 1, characterized in that: The toughening aid is prepared from the following raw materials in parts by weight: POE elastomer 120-150 parts 10-15 parts of long carbon chain alkyl glycidyl ether 8-12 parts of dibutyl itaconate 5-8 parts of vinyl dimethyl-terminated dimethyl-methyltrifluoropropyl polysiloxane copolymer; the long carbon chain alkyl glycidyl ether is dodecyl glycidyl ether and / or tetradecyl glycidyl ether.

3. A TPU composite material for new energy batteries according to claim 1 or 2, characterized in that: The toughening aid is prepared by the following steps: The POE elastomer, long carbon chain alkyl glycidyl ether, dibutyl itaconate and vinyl dimethyl-terminated dimethyl-methyltrifluoropropyl polysiloxane copolymer are melt-extruded and granulated to prepare a toughening additive.

4. The TPU composite material for new energy batteries according to claim 1, characterized in that: The flame retardant consists of melamine cyanurate, ammonium phosphate and magnesium hydroxide in a weight ratio of (0.2-0.4):1:(1-2).

5. The TPU composite material for new energy batteries according to claim 1, characterized in that: The thermal conductive filler is a combination of at least two of boron nitride, aluminum nitride and silicon carbide.

6. The TPU composite material for new energy batteries according to claim 1, characterized in that: The cloth membrane layer is any one of nylon cloth and polypropylene fiber cloth.

7. The TPU composite material for new energy batteries according to claim 1, characterized in that: The adhesive film layer is a polyurethane adhesive film layer, which is prepared by curing polyurethane adhesive, and the polyurethane adhesive is prepared from the following raw materials in parts by weight: 30-40 parts of diisocyanate Polyether diol 8-12 parts Polycaprolactone diol 10-15 parts Chain extender 5-10 parts Catalyst 0.2-0.4 parts.

8. The TPU composite material for new energy batteries according to claim 7, characterized in that: The chain extender is composed of hydroxy polyethylene glycol acrylamide and castor oil modified polyol in a weight ratio of 1:(2-3).

9. The TPU composite material for new energy batteries according to claim 1, characterized in that: The thickness of the adhesive film layer is 5-10 μm, and the thickness of the TPU film layer is 20-30 μm.

10. A process for preparing a TPU composite material for new energy batteries according to any one of claims 7 to 8, characterized in that: The following steps are involved: S1, applying polyurethane glue on the surface of the cloth film layer, drying, and forming a film layer; S2, melt-casting the TPU hot melt adhesive and laminating it on the surface of the adhesive film layer, cooling it, and winding it up to obtain a TPU composite material for new energy batteries.

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