High-temperature-swelling-resistant adhesive tape, preparation method thereof and application of high-temperature-swelling-resistant adhesive tape in lithium battery

Abstract

The invention provides a high-temperature-swelling-resistant adhesive tape, a preparation method thereof and application of the high-temperature-swelling-resistant adhesive tape in a lithium battery. The high-temperature-swelling-resistant adhesive tape comprises a base film and an adhesive layer compounded with the base film, the base film is prepared from the following components in parts by weight: 60 to 70 parts of polyether type thermoplastic polyurethane, 30 to 40 parts of polyester type thermoplastic polyurethane, 0.3 to 0.6 part of plasticizer and 0.1 to 0.3 part of cross-linking agent. The swelling adhesive tape has excellent electrochemical stability, good mechanical strength and reliable sealing performance, and a safer and more efficient solution can be provided in the lithium battery assembly process. In addition, the application of the adhesive tape is also beneficial to improving the overall performance of the battery, prolonging the service life of the battery and enhancing the safety of the battery.

Description

Technical Field

[0001] The invention belongs to the technical field of swelling tapes, and in particular relates to a high temperature resistant swelling tape and a preparation method thereof and application in lithium batteries. Background Art

[0002] With the development of battery technology, the size of cylindrical batteries has become larger and larger, and the safety performance requirements of batteries have become higher and higher. In the actual application of cylindrical batteries, due to frequent shaking and vibration, it is very easy to cause a gap between the battery cell and the outer shell, resulting in relative movement, which poses a great safety hazard. Filling the gap between the battery cell and the outer shell with swelling tape can effectively buffer the frequent shaking and vibration, reduce the relative movement between the battery cell and the outer shell, and play a role in protecting the battery and reducing safety hazards.

[0003] At present, the swelling tapes on the market pay more attention to the swelling performance of the tape's base layer or pressure-sensitive layer at room temperature or below 60°C. However, in actual use, especially during battery operation, whether it is a normal charge and discharge cycle or abnormal working conditions, the temperature inside the battery can easily rise to 70°C or even higher. In such a high temperature environment, the swelling tape may undergo some changes. When the temperature returns to normal levels, the tape may have shape defects, which may lead to its functional failure and inability to effectively protect the battery.

[0004] Therefore, there is an urgent need for a swelling tape with good solubility and swelling rate at high temperature to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a high-temperature resistant swelling tape, a preparation method thereof and an application in a lithium battery. The present invention improves the solubility of the swelling tape at high temperatures by modifying polyethylene glycol with a benzene-containing mixture; at the same time, the present invention compoundes polyether thermoplastic polyurethane and polyester thermoplastic polyurethane to improve the swelling rate of the swelling tape at high temperatures.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A high temperature resistant swelling tape, comprising a base film and an adhesive layer compounded with the base film; the base film comprises the following components in parts by weight: 60-70 parts of polyether thermoplastic polyurethane, 30-40 parts of polyester thermoplastic polyurethane, 0.3-0.6 parts of plasticizer and 0.1-0.3 parts of crosslinking agent;

[0008] The preparation method of the polyether type thermoplastic polyurethane comprises the following steps:

[0009] (1) mixing polyethylene glycol and a benzene-containing mixture in a weight ratio of (1.5-1):1, reacting at 180-200° C. for 4-5 hours, heating to 220-240° C. for further reaction for 4-5 hours, and then continuing to react under vacuum conditions for 1-2 hours to obtain a modified polyether diol;

[0010] (2) 35-37 parts by weight of modified polyether diol and 8-12 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, and 42-45 parts by weight of isophorone diisocyanate are continuously added at a temperature of 100-110° C., and the mixture is reacted for 3-5 hours under heat preservation conditions to obtain a polyether type thermoplastic polyurethane.

[0011] Furthermore, the polyethylene glycol comprises polyethylene glycol 400, polyethylene glycol 800 and polyethylene glycol 2000 in a weight ratio of 1:(1.3-1.6):(0.5-0.7).

[0012] Furthermore, the benzene-containing mixture comprises phthalic acid, terephthalic acid and phthalic anhydride in a weight ratio of 1: (0.2-0.4): (1.4-1.6).

[0013] Furthermore, the preparation method of the polyester thermoplastic polyurethane comprises the following steps: 38-40 parts by weight of polyester diol and 10-12 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, 44-46 parts by weight of isophorone diisocyanate are continuously added at a temperature of 110-120° C., and the mixture is reacted for 3-5 hours under heat preservation conditions to obtain the polyester thermoplastic polyurethane.

[0014] Further, the polyester diol comprises polyester diol A, polyester diol B and polyester diol C in a weight ratio of (1.2-1.4): 1: (0.6-0.8); the molecular weight of the polyester diol A is 1000, and the hydroxyl value is 108-118 mgKOH / g; purchased from Shanghai Huide Technology Co., Ltd., product name HDPOL-4410. The molecular weight of the polyester diol B is 2000, and the hydroxyl value is 53-59 mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., product name HDPOL-4420. The molecular weight of the polyester diol C is 4000, and the hydroxyl value is 26-30 mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., product name HDPOL-4440.

[0015] In the prior art, the swelling tape mainly uses polyether thermoplastic polyurethane, but the swelling tape prepared with it has unsatisfactory solubility at high temperature and cannot maintain its shape. The present invention can improve the solubility of the swelling tape at high temperature by modifying polyethylene glycol with a benzene-containing mixture. Analysis shows that this is because the polyether thermoplastic polyurethane contains a phenyl structure, and the introduction of the phenyl structure can increase the interaction between molecules and help improve the thermal stability of the material. At the same time, the present invention compounded polyether thermoplastic polyurethane and polyester thermoplastic polyurethane to improve the swelling rate of the swelling tape at high temperature. Polyether thermoplastic polyurethane can slow down the swelling process and prevent structural damage caused by excessive absorption of liquid. Polyester thermoplastic polyurethane can provide additional mechanical properties, and its water absorption characteristics can moderately promote swelling. The combination of the two can improve the high-temperature swelling rate of the swelling tape.

[0016] Furthermore, the cross-linking agent is diallyl phthalate.

[0017] Furthermore, the plasticizer comprises the following weight ratio: 2-5 parts of dibutyl phthalate, 11-14 parts of diethyl phthalate and 5-8 parts of diisobutyl phthalate.

[0018] Furthermore, the adhesive layer is polyacrylate pressure-sensitive adhesive.

[0019] Furthermore, the preparation method of the polyacrylate pressure-sensitive adhesive comprises the following steps: heating 60-65 parts of soft monomers, 25-30 parts of hard monomers, 10-15 parts of hydroxyethyl acrylate and 25-30 parts of ethyl acetate to 80-85°C; then adding 0.2-0.3 parts of azobisisobutyronitrile and reacting for 1-1.5 hours; then adding 0.1-0.2 parts of azobisisobutyronitrile, 1-1.5 parts of dodecyl mercaptan and 5-10 parts of toluene-2,4-diisocyanate and reacting for 2-2.5 hours; cooling to room temperature to obtain the polyacrylate pressure-sensitive adhesive.

[0020] Furthermore, the soft monomer is a mixture of n-octyl acrylate, butyl acrylate and isooctyl acrylate in a weight ratio of (0.1-0.3):1:(1.2-1.4).

[0021] Furthermore, the hard monomer is a mixture of hydroxypropyl acrylate, methyl methacrylate and vinyl acetate in a weight ratio of 1: (1.4-1.6): (0.3-0.5).

[0022] The polyacrylate pressure-sensitive adhesive prepared by the present invention has stronger adhesion to the base film and the battery core prepared by the present invention by adjusting the specific ratio of soft monomers and hard monomers, and the annular initial adhesion of the polyacrylate pressure-sensitive adhesive is improved. The soft monomer ratio of the present invention can improve the flexibility and adhesion of the pressure-sensitive adhesive, so that it can better contact with the base film and the surface of the battery core and form a strong bond; the hard monomer provides the necessary cohesion, so that the pressure-sensitive adhesive is not easily peeled off or broken when subjected to external forces; by adjusting the ratio of soft and hard monomers, an optimal balance point can be found between flexibility (adhesion) and cohesion, so as to obtain a bonding effect that is not easy to fall off and has sufficient strength.

[0023] The present invention provides a method for preparing a high temperature resistant swelling tape, the preparation method comprising the following steps:

[0024] (1) feeding the components of the base film into a casting device for making a cast film at a processing temperature of 220-240° C. to prepare a 10-50 μm film as the base film;

[0025] (2) A polyacrylate pressure-sensitive adhesive is coated on the release surface of a 25 μm PET single-sided release film to form an adhesive layer with a thickness of 2-3 μm, and the other side of the adhesive layer is attached to a base film to obtain the swelling tape.

[0026] The invention provides application of a high temperature resistant swelling tape in a lithium battery.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0028] 1. The swelling tape of the present invention has excellent electrochemical stability, good mechanical strength and reliable sealing performance, and can provide a safer and more efficient solution in the lithium battery assembly process. In addition, the application of the tape also helps to improve the overall performance of the battery, extend the battery life, and enhance the safety of the battery.

[0029] 2. The present invention improves the solubility of the swelling tape at high temperature by modifying polyethylene glycol with a benzene-containing mixture. At the same time, the present invention compounded polyether thermoplastic polyurethane and polyester thermoplastic polyurethane to improve the swelling rate of the swelling tape at high temperature.

[0030] 3. The polyacrylate pressure-sensitive adhesive prepared by the present invention has stronger adhesion to the base film and the battery core prepared by the present invention, and the annular initial adhesion is improved. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] The present embodiment provides a high temperature resistant swelling tape, comprising a base film and an adhesive layer compounded with the base film; the base film comprises the following components in parts by weight: 65 parts of polyether thermoplastic polyurethane, 35 parts of polyester thermoplastic polyurethane, 0.4 parts of plasticizer and 0.2 parts of cross-linking agent; the cross-linking agent is diallyl phthalate. The plasticizer is composed of the following components in weight ratio: 4 parts of dibutyl phthalate, 12 parts of diethyl phthalate and 7 parts of diisobutyl phthalate.

[0034] The preparation method of the polyether type thermoplastic polyurethane comprises the following steps:

[0035] (1) Polyethylene glycol and a benzene-containing mixture in a weight ratio of 1.8:1 are mixed, reacted at 190°C for 4.6 hours, heated to 230°C and continued to react for 4.5 hours, and then continued to react under vacuum conditions for 1.5 hours to obtain a modified polyether diol; the polyethylene glycol includes polyethylene glycol 400, polyethylene glycol 800 and polyethylene glycol 2000 in a weight ratio of 1:1.4:0.6. The benzene-containing mixture includes phthalic acid, terephthalic acid and phthalic anhydride in a weight ratio of 1:0.3:1.5.

[0036] (2) 36 parts by weight of modified polyether diol and 10 parts by weight of 1,6-hexanediol were uniformly mixed to obtain a mixture, and 44 parts by weight of isophorone diisocyanate were added at a temperature of 105° C. The mixture was reacted for 4 hours under heat preservation conditions to obtain a polyether thermoplastic polyurethane.

[0037] The preparation method of the polyester thermoplastic polyurethane comprises the following steps: 39 parts by weight of polyester diol and 11 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, 45 parts by weight of isophorone diisocyanate are continuously added at a temperature of 115° C., and the mixture is reacted for 4 hours under heat preservation conditions to obtain the polyester thermoplastic polyurethane.

[0038] The polyester diol includes polyester diol A, polyester diol B and polyester diol C in a weight ratio of 1.3:1:0.7; the molecular weight of the polyester diol A is 1000Da, and the hydroxyl value is 108-118mgKOH / g; purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4410. The molecular weight of the polyester diol B is 2000Da, and the hydroxyl value is 53-59mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4420. The molecular weight of the polyester diol C is 4000Da, and the hydroxyl value is 26-30mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4440.

[0039] The adhesive layer is a polyacrylate pressure-sensitive adhesive. The preparation method of the polyacrylate pressure-sensitive adhesive comprises the following steps: heating 62 parts of soft monomer, 27 parts of hard monomer, 12 parts of hydroxyethyl acrylate and 28 parts of ethyl acetate to 82°C; then adding 0.25 parts of azobisisobutyronitrile and reacting for 1.2 hours; then adding 0.15 parts of azobisisobutyronitrile, 1.3 parts of dodecyl mercaptan and 8 parts of toluene-2,4-diisocyanate and reacting for 2.2 hours; cooling to room temperature to obtain the polyacrylate pressure-sensitive adhesive.

[0040] The soft monomer is a mixture of n-octyl acrylate, butyl acrylate and isooctyl acrylate in a weight ratio of 0.2:1:1.3. The hard monomer is a mixture of hydroxypropyl acrylate, methyl methacrylate and vinyl acetate in a weight ratio of 1:1.5:0.4.

[0041] The method for preparing the swelling tape that rapidly swells when encountering an electrolyte comprises the following steps:

[0042] (1) The components of the base film are added to a casting device for making a cast film at a processing temperature of 230° C. to prepare a 12 μm film as the base film;

[0043] (2) A polyacrylate pressure-sensitive adhesive is coated on the release surface of a 25 μm PET single-sided release film to form an adhesive layer with a thickness of 2 μm, and the other side of the adhesive layer is attached to a base film to obtain the swelling tape.

[0044] Example 2

[0045] This embodiment provides a high temperature resistant swelling tape, comprising a base film and an adhesive layer compounded with the base film; the base film comprises the following components in parts by weight: 60 parts of polyether thermoplastic polyurethane, 40 parts of polyester thermoplastic polyurethane, 0.3 parts of plasticizer and 0.3 parts of crosslinking agent; the crosslinking agent is diallyl phthalate. The plasticizer is composed of the following components in weight ratio: 2 parts of dibutyl phthalate, 14 parts of diethyl phthalate and 5 parts of diisobutyl phthalate.

[0046] The preparation method of the polyether type thermoplastic polyurethane comprises the following steps:

[0047] (1) Polyethylene glycol and a benzene-containing mixture in a weight ratio of 1.5:1 are mixed, reacted at 180°C for 5 hours, heated to 220°C for further reaction for 5 hours, and then reacted under vacuum conditions for further reaction for 2 hours to obtain a modified polyether diol; the polyethylene glycol comprises polyethylene glycol 400, polyethylene glycol 800, and polyethylene glycol 2000 in a weight ratio of 1:1.3:0.7. The benzene-containing mixture comprises phthalic acid, terephthalic acid, and phthalic anhydride in a weight ratio of 1:0.2:1.6.

[0048] (2) 35 parts by weight of modified polyether diol and 12 parts by weight of 1,6-hexanediol were uniformly mixed to obtain a mixture, and 45 parts by weight of isophorone diisocyanate was added at a temperature of 100° C. The mixture was reacted for 3 hours under heat preservation conditions to obtain a polyether thermoplastic polyurethane.

[0049] The preparation method of the polyester thermoplastic polyurethane comprises the following steps: 40 parts by weight of polyester diol and 12 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, 44 parts by weight of isophorone diisocyanate are continuously added at a temperature of 120° C., and the mixture is reacted for 3-5 hours under heat preservation conditions to obtain the polyester thermoplastic polyurethane.

[0050] The polyester diol includes polyester diol A, polyester diol B and polyester diol C in a weight ratio of 1.2:1:0.8; the molecular weight of the polyester diol A is 1000Da, and the hydroxyl value is 108-118mgKOH / g; purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4410. The molecular weight of the polyester diol B is 2000Da, and the hydroxyl value is 53-59mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4420. The molecular weight of the polyester diol C is 4000Da, and the hydroxyl value is 26-30mgKOH / g. Purchased from Shanghai Huide Technology Co., Ltd., the trade name is HDPOL-4440.

[0051] The adhesive layer is a polyacrylate pressure-sensitive adhesive. The preparation method of the polyacrylate pressure-sensitive adhesive comprises the following steps: heating 60 parts of soft monomer, 30 parts of hard monomer, 10 parts of hydroxyethyl acrylate and 30 parts of ethyl acetate to 80°C; then adding 0.3 parts of azobisisobutyronitrile and reacting for 1.5 hours; then adding 0.1 parts of azobisisobutyronitrile, 1.5 parts of dodecyl mercaptan and 5 parts of toluene-2,4-diisocyanate and reacting for 2.5 hours; cooling to room temperature to obtain the polyacrylate pressure-sensitive adhesive.

[0052] The soft monomer is a mixture of n-octyl acrylate, butyl acrylate and isooctyl acrylate in a weight ratio of 0.3:1:1.2. The hard monomer is a mixture of hydroxypropyl acrylate, methyl methacrylate and vinyl acetate in a weight ratio of 1:1.4:0.5.

[0053] The method for preparing the swelling tape that rapidly swells when encountering an electrolyte comprises the following steps:

[0054] (1) The components of the base film are added to a casting device for making a cast film at a processing temperature of 220° C. to prepare a 12 μm film as the base film;

[0055] (2) A polyacrylate pressure-sensitive adhesive is coated on the release surface of a 25 μm PET single-sided release film to form an adhesive layer with a thickness of 2 μm, and the other side of the adhesive layer is attached to a base film to obtain the swelling tape.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 is that 65 parts of polyether thermoplastic polyurethane and 35 parts of polyester thermoplastic polyurethane are replaced by 50 parts of polyether thermoplastic polyurethane and 50 parts of polyester thermoplastic polyurethane.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 1 is that 65 parts of polyether thermoplastic polyurethane and 35 parts of polyester thermoplastic polyurethane are replaced by 100 parts of polyether thermoplastic polyurethane.

[0060] Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that the polyethylene glycol comprises polyethylene glycol 400, polyethylene glycol 800 and polyethylene glycol 2000 in a weight ratio of 1:1:1.

[0062] Comparative Example 4

[0063] The difference between this comparative example and Example 1 is that the benzene-containing mixture comprises phthalic acid, terephthalic acid and phthalic anhydride in a weight ratio of 1:1:1.

[0064] Comparative Example 5

[0065] The difference between this comparative example and Example 1 is that the polyester diol includes polyester diol A, polyester diol B and polyester diol C in a weight ratio of 1:1:1; the molecular weight of the polyester diol A is 1000Da, and the hydroxyl value is 108-118mgKOH / g; the molecular weight of the polyester diol B is 2000Da, and the hydroxyl value is 53-59mgKOH / g; the molecular weight of the polyester diol C is 4000Da, and the hydroxyl value is 26-30mgKOH / g.

[0066] Comparative Example 6

[0067] The difference between this comparative example and Example 1 is that the soft monomer is a mixture of n-octyl acrylate, butyl acrylate and isooctyl acrylate in a weight ratio of 1:1:1.

[0068] Comparative Example 7

[0069] The difference between this comparative example and Example 1 is that the hard monomer is a mixture of hydroxypropyl acrylate, methyl methacrylate and vinyl acetate in a weight ratio of 1:1:1.

[0070] Performance Testing

[0071] 1. Swelling test: The swelling tapes of Examples 1-2 and Comparative Examples 1-7 were cut into square samples with a side length of a1, immersed in electrolyte, and placed at room temperature (25°C) and 90°C for 2 h, respectively. The side length a2 of the sample after immersion was measured, and the swelling rate was ε=(a2-a1) / a1*100%.

[0072] 2. Solubility test: The swollen tapes of Examples 1-2 and Comparative Examples 1-7 were cut into square samples with a side length of a1, immersed in an electrolyte, placed in an environment of 90°C for 48 hours, and the morphology of the samples in the electrolyte was observed:

[0073] ○: represents that the sample morphology is in an expanded state and the morphology remains intact;

[0074] △: Indicates that the sample is in an expanded state, dissolving and breaking, and the shape cannot be kept intact;

[0075] ×: represents that the sample is completely dissolved.

[0076] 3. Loop initial adhesion test: The swelling tape is subjected to a loop initial adhesion test. The test method refers to GB / T31125-2014.

[0077] 4. Bounce test: The swelling tape is tested for bounce. The test method is as follows: The swelling tape is made into a 58mm wide roll, and the sample is placed in a winding device for cylindrical cell winding. Each cell uses a tape with a width of 58mm × length of 54mm. After winding, the cell is left to stand for 4 hours to observe whether the cell bounces. According to different forms, it can be divided into the following states: 1. The cylindrical cell does not change and maintains the original shape; 2. The cylindrical cell bounces, and the swelling tape is loosened from the cell.

[0078] The results are shown in Table 1.

[0079] Table 1 Performance test results

[0080]

[0081]

[0082] Note: / represents not determined.

[0083] The above experimental results show that the hot melt tape provided in Examples 1-2 of the present invention can swell at a high rate in a high-temperature electrolyte at 90°C, and the shape is well maintained without shrinking due to high temperature, and can be used to fill the gap between the lithium battery cell and the shell. At the same time, it can effectively enhance the impact resistance of the lithium battery during daily use, avoid the relative movement of the shell and the cell when the lithium battery falls or is impacted, and cause the battery to fail, thereby extending the service life of the lithium battery and the safety factor of use.

[0084] However, the comparative examples are obviously inferior to the examples in the corresponding performance tests because they do not adopt the necessary technical solutions. In comparative examples 1-2, the compounding ratio of polyether thermoplastic polyurethane and polyester thermoplastic polyurethane is changed, and it can be seen that the swelling rate and solubility at high temperature are reduced. The raw materials of polyether thermoplastic polyurethane and polyester thermoplastic polyurethane prepared in comparative examples 3-5 are changed, and it can be seen from the results that the solubility at high temperature is reduced. The raw materials of polyacrylate pressure-sensitive adhesive in comparative examples 6-7 are different, and the swelling tape is loosened from the battery core, and the bonding effect is reduced. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effect.

[0085] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high temperature resistant swelling tape, characterized in that: It comprises a base film and a glue layer compounded with the base film; the base film comprises the following components in parts by weight: 60-70 parts of polyether thermoplastic polyurethane, 30-40 parts of polyester thermoplastic polyurethane, 0.3-0.6 parts of plasticizer and 0.1-0.3 parts of cross-linking agent; The preparation method of the polyether type thermoplastic polyurethane comprises the following steps: (1) mixing polyethylene glycol and a benzene-containing mixture in a weight ratio of (1.5-1):1, reacting at 180-200° C. for 4-5 hours, heating to 220-240° C. for further reaction for 4-5 hours, and then continuing to react under vacuum conditions for 1-2 hours to obtain a modified polyether diol; (2) 35-37 parts by weight of modified polyether diol and 8-12 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, and 42-45 parts by weight of isophorone diisocyanate are continuously added at a temperature of 100-110° C., and the mixture is reacted for 3-5 hours under heat preservation conditions to obtain a polyether type thermoplastic polyurethane.

2. A high temperature resistant swelling tape according to claim 1, characterized in that: The polyethylene glycol includes polyethylene glycol 400, polyethylene glycol 800 and polyethylene glycol 2000 in a weight ratio of 1: (1.3-1.6): (0.5-0.7).

3. A high temperature resistant swelling tape according to claim 1, characterized in that: The benzene-containing mixture comprises phthalic acid, terephthalic acid and phthalic anhydride in a weight ratio of 1: (0.2-0.4): (1.4-1.6).

4. The high temperature resistant swelling tape according to claim 1, characterized in that: The preparation method of the polyester thermoplastic polyurethane comprises the following steps: 38-40 parts by weight of polyester diol and 10-12 parts by weight of 1,6-hexanediol are uniformly mixed to obtain a mixture, 44-46 parts by weight of isophorone diisocyanate are continuously added at a temperature of 110-120° C., and the mixture is reacted for 3-5 hours under heat preservation conditions to obtain the polyester thermoplastic polyurethane.

5. A high temperature resistant swelling tape according to claim 4, characterized in that: The polyester diol comprises polyester diol A, polyester diol B and polyester diol C in a weight ratio of (1.2-1.4):1:(0.6-0.8); the molecular weight of the polyester diol A is 1000, and the hydroxyl value is 108-118 mgKOH / g; the molecular weight of the polyester diol B is 2000, and the hydroxyl value is 53-59 mgKOH / g; the molecular weight of the polyester diol C is 4000, and the hydroxyl value is 26-30 mgKOH / g.

6. The high temperature resistant swelling tape according to claim 1, characterized in that: The adhesive layer is a polyacrylate pressure-sensitive adhesive; the preparation method of the polyacrylate pressure-sensitive adhesive comprises the following steps: heating 60-65 parts of soft monomers, 25-30 parts of hard monomers, 10-15 parts of hydroxyethyl acrylate and 25-30 parts of ethyl acetate to 80-85°C; then adding 0.2-0.3 parts of azobisisobutyronitrile and reacting for 1-1.5 hours; then adding 0.1-0.2 parts of azobisisobutyronitrile, 1-1.5 parts of dodecyl mercaptan and 5-10 parts of toluene-2,4-diisocyanate and reacting for 2-2.5 hours; cooling to room temperature to obtain the polyacrylate pressure-sensitive adhesive.

7. A high temperature resistant swelling tape according to claim 6, characterized in that: The soft monomer is a mixture of n-octyl acrylate, butyl acrylate and isooctyl acrylate in a weight ratio of (0.1-0.3):1:(1.2-1.4).

8. The high temperature resistant swelling tape according to claim 6, characterized in that: The hard monomer is a mixture of hydroxypropyl acrylate, methyl methacrylate and vinyl acetate in a weight ratio of 1: (1.4-1.6): (0.3-0.5).

9. A method for preparing a high temperature resistant swelling tape according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) feeding the components of the base film into a casting device for making a cast film at a processing temperature of 220-240° C. to prepare a 10-50 μm film as the base film; (2) coating a polyacrylate pressure-sensitive adhesive on the release surface of the release film to form an adhesive layer with a thickness of 2-3 μm, and laminating the other side of the adhesive layer to the base film to obtain the swelling tape.

10. Use of the high temperature swelling resistant adhesive tape according to any one of claims 1 to 8 in lithium batteries.

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