Adhesive, method for producing the same, battery, and electric device

Abstract

The application provides an adhesive, a preparation method of the adhesive, a battery and an electric device. The adhesive comprises 1-35 parts by weight of an olefin polymer, 0.5-10 parts by weight of an alcohol, 0.1-20 parts by weight of a fluorine-containing polymer and 40-99 parts by weight of a solvent, the alcohol has a molar volume of 73 cm 3 / mol-90 cm 3 / mol. The adhesive has good affinity and compatibility between the components, can be uniformly and stably dispersed in the adhesive, can be stored for a long time, does not have adverse problems such as delamination, and is beneficial to the use of the adhesive.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesives, in particular to an adhesive and a preparation method thereof, a battery and an electrical equipment. BACKGROUND

[0002] In order to improve the use reliability of the battery, an adhesive is often used in the battery assembly process. The olefin polymer is a commonly used adhesive component, but it has poor compatibility with the solvent commonly used in the battery adhesive, such as N-methyl pyrrolidone, so that the olefin polymer cannot exist stably in the adhesive, resulting in that the adhesive is prone to delamination. Therefore, the olefin polymer cannot be used alone in the battery adhesive, which affects its use range. SUMMARY

[0003] In view of this, the present application provides an adhesive and a preparation method thereof, a battery and an electrical equipment.

[0004] In a first aspect, the present application provides an adhesive, comprising 1-35 parts by weight of an olefin polymer, 0.5-10 parts by weight of an alcohol, 0.1-20 parts by weight of a fluorine-containing polymer and 40-99 parts by weight of a solvent, the molar volume of the alcohol is 73-90 cm 3 / mol. 3 .

[0005] Optionally, the adhesive comprises 1-25 parts by weight of the olefin polymer, 1-6 parts by weight of the alcohol, 0.5-10 parts by weight of the fluorine-containing polymer and 70-85 parts by weight of the solvent.

[0006] Optionally, the weight ratio of the alcohol to the fluorine-containing polymer is 0.1-1.5.

[0007] Optionally, the solvent contact angle of the olefin polymer is less than or equal to 20°.

[0008] Optionally, the solvent contact angle of the fluorine-containing polymer is less than or equal to 10°.

[0009] Optionally, the adhesive has a hydrogen bond between the olefin polymer and the alcohol.

[0010] Optionally, the polarity of the solvent is greater than or equal to the polarity of N-methyl pyrrolidone.

[0011] Optionally, the solvent comprises at least one of N-methyl pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-diethylformamide.

[0012] Optionally, the melting point of the olefin polymer is 70-85℃.

[0013] Optionally, the olefin polymer comprises at least one of ethylene-acrylic acid polymer and ethylene-methacrylic acid polymer.

[0014] Optionally, the alcohol comprises at least one of isopropyl alcohol and n-propyl alcohol.

[0015] Optionally, the fluorine-containing polymer comprises polyvinylidene fluoride.

[0016] In a second aspect, the application provides a preparation method of an adhesive, comprising: mixing an olefin polymer, an alcohol, a fluorine-containing polymer and a solvent to obtain an adhesive, wherein the adhesive comprises 1-35 parts by weight of the olefin polymer, 0.5-10 parts by weight of the alcohol, 0.1-20 parts by weight of the fluorine-containing polymer and 40-99 parts by weight of the solvent, the molar volume of the alcohol is 73-90 cm 3 / mol. 3 / mol.

[0017] Optionally, the mixing temperature is 90-120℃.

[0018] In a third aspect, the application provides a battery comprising a pole piece, a diaphragm and a connecting layer arranged between the pole piece and the diaphragm, wherein the connecting layer is formed by drying the adhesive prepared by the preparation method of the second aspect.

[0019] In a fourth aspect, the application provides an electrical equipment comprising the battery of the third aspect.

[0020] The adhesive provided by the application has good affinity and compatibility between the components, can be uniformly and stably dispersed, can be stored for a long time without adverse problems such as delamination, is conducive to the use of the adhesive in the battery, and improves the reliability of the battery structure. DETAILED DESCRIPTION

[0021] The technical solutions of the application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0022] The adhesive provided by the application comprises 1-35 parts by weight of an olefin polymer, 0.5-10 parts by weight of an alcohol, 0.1-20 parts by weight of a fluorine-containing polymer and 40-99 parts by weight of a solvent, and the molar volume of the alcohol is 73-90 cm 3 / mol-90cm 3 The fluorine atom in the fluorine-containing polymer of the adhesive has strong polarity, good compatibility with the solvent, and can exist stably in the solvent. The fluorine-containing polymer and the olefin polymer are both long carbon chain structures, and the van der Waals force between the two makes the fluorine-containing polymer act as a bridge to connect the non-polar segment of the olefin polymer and the solvent. The molar volume of the fluorine-containing polymer is 73 cm 3 / mol-90cm 3 The alcohol has good compatibility with the solvent and can exist stably in the solvent, and the olefin polymer has a certain polarity, so that the alcohol and the olefin polymer can interact, and the alcohol can act as a bridge to connect the olefin polymer and the solvent, so that the olefin polymer, which plays a main bonding role, can exist stably in the solvent for a long time. Therefore, each component of the adhesive can exist stably, the overall system is stable and reliable, and long-term storage will not cause problems such as delamination, which is conducive to the use of the adhesive. At the same time, each component of the adhesive has good matching performance with the battery system, and can be used in the assembly and connection of the battery, which is conducive to the wide use of the adhesive.

[0023] The olefin polymer in the adhesive of the present application plays a main bonding role, ensuring the bonding performance of the adhesive. At the same time, under the action of the fluorine-containing polymer and the alcohol, the olefin polymer can exist stably in the solvent, ensuring the stability of the adhesive system. The content of the olefin polymer in the adhesive is 1-35 parts by weight. If the content of the olefin polymer is too low, the bonding performance of the adhesive will be affected. If the content of the olefin polymer is too high, the adhesive is prone to delamination. Therefore, 1-35 parts by weight of the olefin polymer ensures the connection and stability of the adhesive. Specifically, the parts by weight of the olefin polymer in the adhesive can be, but is not limited to, 1 part, 3 parts, 5 parts, 6 parts, 7 parts, 8 parts, 10 parts, 12 parts, 15 parts, 17 parts, 18 parts, 19 parts, 20 parts, 23 parts, 25 parts, 27 parts, 30 parts, 31 parts, 33 parts, or 35 parts, etc. In an embodiment of the present application, the adhesive can include 1-25 parts by weight of the olefin polymer, further improving the bonding performance of the adhesive. In an embodiment of the present application, the adhesive can include 10-25 parts by weight of the olefin polymer, which is conducive to further improving the bonding performance of the adhesive.

[0024] In an embodiment of the present application, the solvent contact angle of the olefin polymer is less than or equal to 20°, so that the olefin polymer has better affinity with the solvent and is more easily stably dispersed in the solvent, further improving the stability of the adhesive. Specifically, the solvent contact angle of the olefin polymer can be, but is not limited to, 19° or less, 18° or less, 17° or less, 16° or less, 15° or less, 14° or less, 13° or less, 12° or less, or 11° or less, etc. In the present application, a contact angle tester can be used to detect the solvent contact angle of the olefin polymer; for example, an olefin polymer film is arranged on a flat surface, a solvent is dropped on the olefin polymer film, and a contact angle tester is used to detect the contact angle, thereby obtaining the solvent contact angle of the olefin polymer.

[0025] In the present application, a low-melting-point olefin polymer can be used, thereby facilitating the use of the adhesive at a lower temperature. In an embodiment of the present application, the melting point of the olefin polymer is 70-85°C, which is conducive to the use of the adhesive at a lower temperature (e.g., 100°C or less). That is, the adhesive is heated to a temperature above the melting point of the olefin polymer, so that the flowability of the olefin polymer is increased, the adhesion of the adhesive to the bonding object is improved, and the bonding effect can be achieved after cooling. Specifically, the melting point of the olefin polymer can be, but is not limited to, 70°C, 72°C, 75°C, 78°C, 80°C, 82°C, 83°C, or 85°C, etc. In an embodiment of the present application, the melting point of the olefin polymer can be 72-80°C.

[0026] In an embodiment of the present application, the olefin polymer has a polar group, so that intermolecular forces can be generated between the alcohol and the olefin polymer, and the alcohol can serve as a bridge to connect the polar segment of the olefin polymer and the solvent, thereby improving the stability of the olefin polymer in the adhesive. In an embodiment of the present application, the olefin polymer is a carboxyl-containing olefin polymer. In an embodiment, the olefin polymer includes at least one of an ethylene-acrylic acid polymer and an ethylene-methacrylic acid polymer. The above-mentioned olefin polymer has a low melting point, which is conducive to the use of the adhesive at a lower temperature, reduces the use cost of the adhesive, and is more conducive to the widespread use of the adhesive. In an embodiment, the ethylene-acrylic acid polymer can be formed by polymerization of ethylene monomers and acrylic acid monomers, and the mass ratio of the acrylic acid monomers to the sum of the mass of the ethylene monomers and the mass of the acrylic acid monomers is greater than or equal to 17%, thereby facilitating the obtaining of an olefin polymer with a low melting point. In an embodiment, the ethylene-methacrylic acid polymer can be formed by polymerization of ethylene monomers and methacrylic acid monomers, and the mass ratio of the methacrylic acid monomers to the sum of the mass of the ethylene monomers and the mass of the methacrylic acid monomers is greater than or equal to 17%, thereby facilitating the obtaining of an olefin polymer with a low melting point.

[0027] The fluorine atom in the fluorine-containing polymer in the adhesive has strong polarity, good compatibility with the solvent, and can exist stably in the solvent. The fluorine-containing polymer and the olefin polymer are both long carbon chain structures, and the van der Waals force between the two makes the fluorine-containing polymer act as a bridge to connect the non-polar segment of the olefin polymer and the solvent. Therefore, the fluorine-containing polymer ensures the affinity and compatibility between the non-polar segment of the olefin polymer and the solvent, and also has certain bonding performance. The adhesive contains 0.1-20 parts by weight of fluorine-containing polymer. If the content of the fluorine-containing polymer is too low, the adhesive is prone to delamination. If the content of the fluorine-containing polymer is too high, the adhesive has poor bonding performance. Therefore, 0.1-20 parts by weight of fluorine-containing polymer ensures the connection and stability of the adhesive. Specifically, the parts by weight of the fluorine-containing polymer in the adhesive can be, but is not limited to, 0.1, 0.5, 1, 2, 3, 5, 7, 9, 10, 12, 14, 15, 17, 18 or 20, etc. In an embodiment of the present application, the adhesive can include 0.5-10 parts by weight of fluorine-containing polymer, further improving the compatibility between the olefin polymer and the solvent and improving the storage stability of the adhesive. In an embodiment of the present application, the adhesive can include 1-8 parts by weight of fluorine-containing polymer, which is beneficial to further improve the storage stability of the adhesive.

[0028] In an embodiment of the present application, the solvent contact angle of the fluorine-containing polymer is less than or equal to 10°, so that the affinity and binding strength between the fluorine-containing polymer and the solvent are better, and the fluorine-containing polymer is more easily stably dispersed in the solvent. At the same time, the affinity between the olefin polymer and the solvent is also improved, and the stability of the adhesive is further improved. Specifically, the solvent contact angle of the fluorine-containing polymer can be, but is not limited to, less than 9°, less than 8°, less than 5°, less than 6°, less than 5°, less than 4° or less than 3°, etc. In the present application, a contact angle tester can be used to detect the solvent contact angle of the fluorine-containing polymer; for example, a fluorine-containing polymer film is arranged on a plane, and a solvent is dropped on the fluorine-containing polymer film, and the contact angle is detected by the contact angle tester to obtain the solvent contact angle of the fluorine-containing polymer.

[0029] In an embodiment of the present application, the weight fraction of the olefin polymer in the adhesive is greater than or equal to the weight fraction of the fluoropolymer, which is conducive to the stable dispersion of the olefin polymer in the solvent, ensuring the stability of the adhesive, and is also conducive to improving the bonding performance of the adhesive. Moreover, the melting point of the olefin polymer is lower than that of the fluoropolymer, which is conducive to reducing the use temperature of the adhesive. In an embodiment of the present application, the weight ratio of the olefin polymer to the fluoropolymer is 1-10, which is conducive to further improving the stability and bonding performance of the adhesive. In an embodiment of the present application, the weight ratio of the olefin polymer to the fluoropolymer can be 1.5-5, which is conducive to further improving the use performance of the adhesive.

[0030] In an embodiment of the present application, the fluoropolymer includes polyvinylidene fluoride. The affinity of polyvinylidene fluoride to the solvent is good, which is conducive to its stable existence in the solvent, and the affinity between polyvinylidene fluoride and the olefin polymer is good, which is conducive to the stable existence of the olefin polymer, further improving the stability of the adhesive.

[0031] The alcohol with a molar volume of 73 cm 3 / mol-90 cm 3 / mol in the adhesive of the present application has good compatibility with the solvent and can exist stably in the solvent, and the alcohol has intermolecular forces with the polar segment of the olefin polymer, so the alcohol can connect the polar segment of the olefin polymer and the solvent as a bridge. Therefore, the alcohol with a molar volume of 73 cm 3 / mol-90 cm 3 / mol ensures the affinity and compatibility between the polar segment of the olefin polymer and the solvent, and further ensures the storage stability of the adhesive. The adhesive contains 0.5-10 parts by weight of alcohol. If the content of the alcohol is too low, the adhesive is prone to delamination, and if the content of the alcohol is too high, the adhesive has poor bonding performance. Therefore, 0.5-10 parts by weight of alcohol ensures the connection and stability of the adhesive. Specifically, the weight fraction of the alcohol in the adhesive can be, but is not limited to, 0.5 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight or 10 parts by weight, etc. In an embodiment of the present application, the adhesive can include 1-6 parts by weight of alcohol, which further improves the compatibility between the olefin polymer and the solvent and improves the storage stability of the adhesive. In an embodiment of the present application, the adhesive can include 2-5 parts by weight of alcohol, which is conducive to further improving the storage stability of the adhesive.

[0032] In an embodiment of the present application, the hydrogen bond exists between the olefin polymer and the alcohol in the adhesive. The hydrogen bond between the alcohol and the olefin polymer further improves the stability of the olefin polymer in the adhesive. For example, the carboxyl and / or carbonyl in the olefin polymer can form a hydrogen bond with the alcohol. In an embodiment of the present application, the olefin polymer includes a carboxyl-containing olefin polymer, which can not only form a hydrogen bond with the alcohol, but also improve the bonding performance of the adhesive. The generated hydrogen bond can be detected by infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance, X-ray diffraction, etc. For example, the Fourier infrared spectrum of the adhesive can be tested, and the change in the absorption peak intensity and the position shift of the carboxyl and / or carbonyl in the infrared spectrum can represent the generation of the hydrogen bond.

[0033] In an embodiment of the present application, the weight fraction of the olefin polymer in the adhesive is greater than the weight fraction of the alcohol, which is conducive to the stable dispersion of the olefin polymer in the solvent, ensuring the stability of the adhesive, and also conducive to improving the bonding performance of the adhesive.

[0034] In an embodiment of the present application, the weight fraction ratio of the alcohol to the fluorine-containing polymer is 0.1-1.5, which is conducive to further improving the affinity of the olefin polymer and the solvent, further improving the stability of the adhesive, and avoiding the occurrence of delamination. Specifically, the weight fraction ratio of the alcohol to the fluorine-containing polymer can be but is not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5, etc.

[0035] In an embodiment of the present application, the alcohol includes at least one of isopropyl alcohol and n-propanol. The above-mentioned alcohol has good compatibility with the solvent and good affinity with the olefin polymer, which is conducive to the stable storage of the adhesive, and the preparation process of the adhesive does not produce filter residue, and the uniformity is good.

[0036] The solvent in the adhesive of the present application is used to dissolve and disperse other components in the adhesive. The adhesive contains 40-99 parts by weight of the solvent. If the content of the solvent is too low, the dispersion of other components is affected, and the adhesive is prone to delamination. If the content of the solvent is too high, the bonding performance of the adhesive is poor. Therefore, 40-99 parts by weight of the solvent ensures the bonding effect and stability of the adhesive. Specifically, the weight fraction of the solvent in the adhesive can be but is not limited to 50 parts by weight, 60 parts by weight, 70 parts by weight, 75 parts by weight, 78 parts by weight, 80 parts by weight, 82 parts by weight, or 90 parts by weight, etc. In an embodiment of the present application, the adhesive can include 70-85 parts by weight of the solvent, which further improves the storage stability and bonding performance of the adhesive.

[0037] In an embodiment of the present application, the solvent is a polar solvent, thereby facilitating the mixing and uniform and stable dispersion of other components in the adhesive. In an embodiment of the present application, the polarity of the solvent is greater than or equal to the polarity of N-methyl pyrrolidone, the polarity of the solvent in the adhesive of the present application is greater than or equal to the polarity of N-methyl pyrrolidone, the polarity is strong, which can match the commonly used solvents in the battery system, and meanwhile the components can be stably dispersed in the solvent, the adhesive system is stable and reliable, and is conducive to the use of the adhesive.

[0038] In an embodiment of the present application, the boiling point of the solvent is greater than or equal to 150°C, which is conducive to the use of the adhesive at low temperature. Specifically, the boiling point of the solvent can be but is not limited to 150°C or higher, 155°C or higher, 160°C or higher, 165°C or higher, 170°C or higher, or 175°C or higher.

[0039] In an embodiment of the present application, the solvent includes at least one of N-methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and N,N-diethylformamide (DEF). The above-mentioned solvents are commonly used solvents in the battery system, which are conducive to the use of the adhesive in the assembly and connection of the battery. For example, the pole piece of the battery has an active material layer, which is prepared by coating and drying a slurry containing active material, and the solvent in the slurry can include but is not limited to at least one of N-methyl pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylformamide, and the solvent in the adhesive of the present application also includes at least one of N-methyl pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylformamide, which ensures the affinity of the adhesive to the slurry containing active material, avoids the pollution or damage to the active material layer, ensures the use performance of the prepared pole piece and battery, and is also conducive to the recycling of N-methyl pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylformamide. In an embodiment of the present application, the solvent includes N-methyl pyrrolidone. The fluorine atoms in the fluoropolymer have good affinity with the carbonyl group of N-methyl pyrrolidone, which improves the wettability of the fluoropolymer with N-methyl pyrrolidone, and the fluoropolymer is easily dissolved and uniformly and stably dispersed in N-methyl pyrrolidone.

[0040] In an embodiment of the present application, the adhesive includes 1-25 parts by weight of the olefin polymer, 1-6 parts by weight of the alcohol, 0.5-10 parts by weight of the fluoropolymer, and 70-85 parts by weight of the solvent, which is conducive to further improving the stability and bonding performance of the adhesive.

[0041] In an embodiment of the present application, the adhesive is composed of an olefin polymer, an alcohol, a fluorine-containing polymer and a solvent. Without adding an auxiliary such as an initiator and a leveling agent, the adhesive can still maintain good storage stability, color uniformity, no yellow edge, no delamination during long-term storage and good bonding performance, which is beneficial to the use of the adhesive.

[0042] In an embodiment of the present application, the viscosity of the adhesive is 1500 mPa.s-5000 mPa.s. The viscosity of the adhesive is suitable, which is beneficial to the coating and bonding of the adhesive. Specifically, the viscosity of the adhesive can be, but is not limited to, 1500 mPa.s, 1800 mPa.s, 2000 mPa.s, 2300 mPa.s, 2500 mPa.s, 2700 mPa.s, 3000 mPa.s, 3500 mPa.s, 4000 mPa.s, 4500 mPa.s or 5000 mPa.s, etc.

[0043] The present application provides a preparation method of an adhesive, which comprises: mixing an olefin polymer, an alcohol, a fluorine-containing polymer and a solvent to obtain an adhesive. The adhesive comprises 1-35 parts by weight of the olefin polymer, 0.5-10 parts by weight of the alcohol, 0.1-20 parts by weight of the fluorine-containing polymer and 40-99 parts by weight of the solvent. The molar volume of the alcohol is 73 cm 3 / mol-90 cm 3 / mol. In the adhesive provided by the present application, each component can be stably dispersed, and the adhesive will not delaminate during storage, which is beneficial to the use of the adhesive. Meanwhile, in the preparation of the adhesive of the present application, the components are directly mixed to obtain the adhesive. Compared with a chemical method, the preparation method of the adhesive of the present application is simpler and more reliable, has low preparation difficulty and is beneficial to the industrialized production of the adhesive.

[0044] In an embodiment of the present application, the temperature of the mixing is greater than the melting point of the olefin polymer and less than the boiling point of each component. It can be understood that the olefin polymer plays a major role in the adhesive in bonding components, and the temperature of the mixing is greater than the melting point of the olefin polymer can make the olefin polymer in a flow state, which is conducive to the uniform and stable dispersion of the olefin polymer in the adhesive, and at the same time, the temperature of the mixing is less than the boiling point of each component (olefin polymer, alcohol, fluorine-containing polymer, solvent), which ensures the stable existence of each component during mixing and avoids the loss of components caused by high temperature. In an embodiment of the present application, the temperature of the mixing is 90-120℃, which is conducive to the sufficient mixing of each component and improves the uniformity and stability of the adhesive. Specifically, the temperature of the mixing can be but is not limited to 90℃, 92℃, 95℃, 98℃, 100℃, 105℃, 107℃, 110℃, 113℃, 115℃, 117℃ or 120℃, etc. In an embodiment of the present application, the mixing time can be more than 2h to make each component mix uniformly. During the mixing process, the mixing can be carried out while stirring; after the mixing, cooling and filtration can be carried out to remove impurities and improve the purity of the adhesive. Specifically, the filtration can be but is not limited to carried out through a filter cloth with a mesh size of 200.

[0045] The present application provides a battery, which comprises a pole piece, a diaphragm and a connecting layer arranged between the pole piece and the diaphragm, and the connecting layer is formed by drying the adhesive in any of the above embodiments. The adhesive has excellent bonding performance and is suitable for the battery system, and the connecting layer formed by drying can connect the pole piece and the diaphragm, which is conducive to the use of the battery.

[0046] In an embodiment of the present application, the pole piece includes an active material layer disposed on the surface of the current collector. In an embodiment of the present application, the current collector includes a first region and a second region, the active material layer is disposed on the first region, and the connecting layer is disposed on the second region. The first region and the second region can be adjacently disposed or spaced apart. Specifically, the first region can be coated with a slurry containing the active material, and the second region can be coated with an adhesive, and the separator is disposed in contact with the adhesive to form the active material layer and the connecting layer connecting the pole piece and the separator. The separator can be disposed in contact with the adhesive by hot pressing, and the hot pressing temperature can be below 100°C, so that the adhesive can be embedded in the separator to provide more reliable and firm adhesion. The adhesive can also be mixed with an insulating ceramic material (such as boehmite, etc.) and coated on the second region. The current collector raw material can be cut to the desired size as needed during the production of the pole piece. During the cutting process, burrs are inevitably formed at the edge position of the current collector, which can easily pierce the separator to cause short circuit between the positive electrode and the negative electrode, affecting the safety of the battery. The connecting layer can be disposed in the edge region (second region) of the current collector to prevent the burrs at the edge position of the current collector from easily piercing the separator to cause short circuit of the battery, thereby improving the safety of the battery. The connecting layer can also play a good bonding and fixing role to prevent the battery pole piece from being misaligned during the assembly process or during the movement of the battery after assembly, thereby avoiding affecting the performance of the battery and ensuring the stability of the battery.

[0047] The present application provides a power consuming device including the battery of any of the above embodiments. The power consuming device has excellent use performance and strong product competitiveness. The power consuming device can refer to a vehicle, an electronic device (such as a mobile phone, a computer, a camera, etc.), an energy storage system, etc. The above battery can be disposed in the power consuming device in the form of a single battery, a battery module, a battery pack, etc.

[0048] The effects of the technical solutions of the present application are further described below through specific examples.

[0049] Example 1

[0050] The adhesive includes 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, and melting point of 75°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, isopropyl alcohol, polyvinylidene fluoride, and NMP are uniformly mixed, heated to 110°C and stirred until dissolved, then stirred and cooled to room temperature, and then filtered with a 200-mesh filter cloth to obtain the adhesive. The filter cloth has no filter residue.

[0051] Example 2

[0052] The adhesive included 15.8 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 18%, NMP contact angle of 19°, and melting point of 85°C), 3.3 parts by weight of isopropanol (molar volume of 75.9 cm3 / mol), 3.5 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 77.4 parts by weight of NMP. 3

[0053] Example 3

[0054] The adhesive included 15.8 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 18%, NMP contact angle of 19°, and melting point of 85°C), 3.3 parts by weight of isopropanol (molar volume of 75.9 cm3 / mol), 3.5 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 77.4 parts by weight of NMP. 3

[0055] Example 4

[0056] The adhesive included 6.66 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 15°, and melting point of 75°C), 1.2 parts by weight of isopropanol (molar volume of 75.9 cm3 / mol), 10 parts by weight of polyvinylidene fluoride (NMP contact angle of 10°), and 82.14 parts by weight of NMP. 3

[0057] Example 5

[0058] The adhesive included 18 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 15°, and melting point of 75°C), 4 parts by weight of isopropanol (molar volume of 75.9 cm3 / mol), 2.7 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 73.6 parts by weight of NMP. 3

[0059] Example 6

[0060] The adhesive included 14.9 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, and melting point of 75°C), 7 parts by weight of isopropanol (molar volume of 75.9 cm3 / mol), 5 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 72.6 parts by weight of NMP. 3

[0061] Example 7

[0062] ​​​​​The adhesive comprises 10.5 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 2.1 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 10.3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 77.1 parts by weight of NMP.

[0063] Example 8

[0064] The adhesive comprises 13.8 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 19%, NMP contact angle of 21°, melting point of 75°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 12°), and 80.2 parts by weight of NMP.

[0065] Example 9

[0066] The adhesive comprises 13.8 parts by weight of an ethylene-methacrylic acid copolymer (methacrylic acid monomer mass content of 24%, NMP contact angle of 18°, melting point of 73°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of NMP; wherein the ethylene-methacrylic acid copolymer, isopropyl alcohol, polyvinylidene fluoride, and NMP are mixed uniformly, heated to 90°C and stirred until dissolved, then stirred to cool to room temperature, and the resulting mixture is filtered through a 200-mesh filter cloth to obtain the adhesive, with no residue on the filter cloth.

[0067] Example 10

[0068] The adhesive comprises 13.8 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of N,N-dimethylformamide.

[0069] Example 11

[0070] The adhesive comprises 9 parts by weight of an ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 10 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 6 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 75 parts by weight of NMP.

[0071] Comparative Example 1

[0072] The adhesive comprises 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 83.2 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, polyvinylidene fluoride, and NMP are mixed uniformly, then heated to 110°C and stirred until dissolved, and then stirred to cool to room temperature, after which the glue solution is in the form of a paste that does not flow and cannot be filtered with filter cloth.

[0073] Comparative Example 2

[0074] The adhesive comprises 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of glycerol (molar volume of 70.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, glycerol, polyvinylidene fluoride, and NMP are mixed uniformly, then heated to 110°C and stirred until dissolved, and then stirred to cool to room temperature, after which the glue solution is in the form of a paste that does not flow and cannot be filtered.

[0075] Comparative Example 3

[0076] The adhesive comprises 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of tert-butyl alcohol (molar volume of 92.1 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, tert-butyl alcohol, polyvinylidene fluoride, and NMP are mixed uniformly, then heated to 110°C and stirred until dissolved, and then stirred to cool to room temperature, after which the glue solution is filtered with 200-mesh filter cloth to obtain the adhesive.

[0077] Comparative Example 4

[0078] The adhesive comprises 15.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 18%, NMP contact angle of 19°, melting point of 85°C), 11 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 6 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 77.7 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, isopropyl alcohol, polyvinylidene fluoride, and NMP are mixed uniformly, then heated to 110°C and stirred until dissolved, and then stirred to cool to room temperature, after which the glue solution is filtered with 200-mesh filter cloth to obtain the adhesive.

[0079] Comparative Example 5

[0080] The adhesive comprises 15.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 18%, NMP contact angle of 19°, melting point of 85°C), 3.5 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 80.7 parts by weight of NMP; wherein the ethylene-acrylic acid copolymer, polyvinylidene fluoride, and NMP are mixed uniformly, then heated to 110°C and stirred until dissolved, and then stirred to cool to room temperature before filtering the product with a 200-mesh filter cloth, but the filtration resistance is too large to filter.

[0081] Comparative Example 6

[0082] After 37 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 9 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 3 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 90 parts by weight of NMP are mixed uniformly, the temperature is increased to 125°C and stirred, but the particles still swell, the resin does not dissolve, and it cannot be used.

[0083] Comparative Example 7

[0084] After 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 0.05 parts by weight of polyvinylidene fluoride (NMP contact angle of 8°), and 80.2 parts by weight of NMP are mixed uniformly, the temperature is increased to 125°C and stirred, but the particles still swell, the resin does not dissolve, and it cannot be used.

[0085] Comparative Example 8

[0086] After 5 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3 / mol), 16.8 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 78.2 parts by weight of NMP are mixed, the temperature is increased to 120°C and stirred, but the powder is partially insoluble and has no flowability.

[0087] Comparative Example 9

[0088] The adhesive comprises 13.8 parts by weight of ethylene-acrylic acid copolymer (acrylic acid monomer mass content of 20.5%, NMP contact angle of 17°, melting point of 75°C), 3 parts by weight of isopropyl alcohol (molar volume of 75.9 cm 3mol), 22 parts by weight of polyvinylidene fluoride (NMP contact angle of 9°), and 61.2 parts by weight of NMP were mixed and stirred at an elevated temperature of 120°C, the resin did not dissolve, part of the powder did not dissolve, and there was no fluidity.

[0089] Performance detection

[0090] The viscosity of the adhesives prepared in the above examples and comparative examples was detected, 200 g of the adhesive was poured into a polypropylene bottle with a diameter of 73 mm and a height of 90 mm, and the viscosity was detected using a Brookfield viscometer DV2THBTJ0, 5# rotor, 25°C, and a rotation speed of 100 rpm. The stability of the adhesives prepared in the above examples and comparative examples was detected, 9 g of the adhesive was introduced into a 10 ml centrifuge tube, and centrifugation was performed at rotation speeds of 3000 rpm, 5000 rpm, and 7000 rpm for 5 min, respectively. If stratification occurred, the test was stopped. If no stratification occurred after all rotation speeds were tested, the sample (80 g) was taken again and placed in a 100 ml transparent storage bottle, which was sealed and placed in a constant temperature room. The sample was observed once a day, and whether stratification occurred was recorded. The melting peak of the adhesives prepared in the above examples and comparative examples was detected, 5 g of the adhesive was poured into a release paper tank and placed in a 150°C air drying oven for 2 h to prepare a solid adhesive. The melting point of the obtained solid adhesive was tested using a simultaneous thermal analyzer, including heating from room temperature to 150°C at a rate of 5°C / min under an inert atmosphere, and the temperature corresponding to the peak value of the melting peak was read. The performance detection results are shown in Table 1.

[0091] Table 1 Performance detection results

[0092]

[0093]

[0094] The products prepared in Comparative Examples 1-2 and 5-9 could not be measured for viscosity, stability, and melting peak, and the prepared products could not be used, let alone used as adhesives. The stability of the adhesives prepared in Comparative Examples 3-4 was poor, and the adhesive prepared in Comparative Example 4 had no melting peak below 100°C, indicating that its use temperature was high and it could not be used at a lower temperature (below 100°C). Compared with the comparative examples, the adhesives prepared in the examples of the present application used alcohols with a molar volume of 73 cm 3 / mol-90 cm 3 / mol and the components matched each other, and the viscosity of the prepared adhesives was suitable and the system stability was high, which could be stored for a long time. Compared with Examples 6-8 and Example 11, the adhesives prepared in Examples 1-5 and Examples 9-10 had better stability and were suitable for longer storage. At the same time, the adhesives prepared in the examples had a melting peak below 100°C, which was beneficial to the use of the adhesives at a lower temperature and widened the application scenarios of the adhesives.

[0095] The above describes exemplary embodiments of the present application, but should not be construed as limiting the scope of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements are also considered within the scope of the present application.

Claims

1. An adhesive, characterized in that, It is composed of 1-35 parts by weight of an olefin polymer, 0.5-10 parts by weight of an alcohol, 0.1-20 parts by weight of a fluoropolymer, and 40-99 parts by weight of a solvent, wherein the molar volume of the alcohol is 73 cm³. 3 / mol-90cm 3 / mol, wherein the olefin polymer is at least one of ethylene-acrylic acid polymer and ethylene-methacrylic acid polymer, the alcohol is at least one of isopropanol and n-propanol, the fluorinated polymer is polyvinylidene fluoride, and the solvent is at least one of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-diethylformamide.

2. The adhesive as described in claim 1, characterized in that, The adhesive is composed of 1-25 parts by weight of the olefin polymer, 1-6 parts by weight of the alcohol, 0.5-10 parts by weight of the fluoropolymer, and 70-85 parts by weight of the solvent.

3. The adhesive as described in claim 1 or 2, characterized in that, The weight ratio of the alcohol to the fluoropolymer is 0.1-1.

5.

4. The adhesive as described in claim 1, characterized in that, The solvent contact angle of the olefin polymer is less than or equal to 20°; The solvent contact angle of the fluoropolymer is less than or equal to 10°.

5. The adhesive as described in claim 1, characterized in that, The olefin polymer and the alcohol in the adhesive have hydrogen bonds.

6. The adhesive as described in claim 1, characterized in that, The melting point of the olefin polymer is 70℃-85℃.

7. A method for preparing an adhesive, characterized in that, include: An adhesive is obtained by mixing an olefin polymer, an alcohol, a fluoropolymer, and a solvent. The adhesive comprises 1-35 parts by weight of an olefin polymer, 0.5-10 parts by weight of an alcohol, 0.1-20 parts by weight of a fluoropolymer, and 40-99 parts by weight of a solvent. The molar volume of the alcohol is 73 cm³. 3 / mol-90cm 3 / mol, wherein the olefin polymer is at least one of ethylene-acrylic acid polymer and ethylene-methacrylic acid polymer, the alcohol is at least one of isopropanol and n-propanol, the fluorinated polymer is polyvinylidene fluoride, and the solvent is at least one of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-diethylformamide.

8. The preparation method according to claim 7, characterized in that, The mixing temperature is 90℃-120℃.

9. A battery, characterized in that, It includes an electrode, a diaphragm, and a connecting layer disposed between the electrode and the diaphragm, wherein the connecting layer is formed by drying an adhesive prepared by any one of claims 1-6 or by any one of claims 7-8.

10. An electrical appliance, characterized in that, Includes the battery as described in claim 9.

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