Glue for composite current collector, preparation method of glue and composite current collector

Abstract

The invention belongs to the technical field of acrylic glue, and particularly relates to glue for a composite current collector, a preparation method of the glue and the composite current collector, and the preparation method comprises the following steps: S1, dissolving tetra-n-butyl tetraphenyl ammonium borate in deionized water to prepare a modified solution; s2, hollow silicon dioxide particles are added into the modified solution, the reaction temperature is controlled to be 70-75 DEG C, stirring reaction is conducted for 1-1.5 h, and pre-modified particles are obtained; s3, filtering to remove reaction residues which are not completely reacted on the surfaces of the pre-modified particles, washing with deionized water, and drying at 90-95 DEG C to obtain modified particles; s4, adding the modified particles into acrylic acid glue, and stirring for 0.5-1 hour to obtain glue for the composite current collector; according to the invention, tetra-n-butyl tetraphenyl ammonium borate is combined with hydroxyl groups on the surfaces of hollow silicon dioxide particles to form an organic-inorganic hybrid interface, benzene rings and boric acid groups in the molecular structure can provide thermal stability, and a synergistic effect is formed in cooperation with the heat resistance of silicon dioxide, so that the high-temperature tolerance of a glue system can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of acrylic adhesives, and particularly relates to an adhesive for composite current collectors, a preparation method thereof, and a composite current collector. Background Art

[0002] In modern industrial manufacturing, the bonding of polymer materials and metal materials is one of the key processes in many fields. In the field of composite current collectors, due to the large differences in the surface chemical properties and physical characteristics of polymer materials and metal materials, existing adhesives mostly focus on improving the bonding strength.

[0003] In practical applications, the adhesive needs to remain stable during the hot pressing (70 - 150 °C) and curing (80 - 150 °C) processes. If the thermal stability of the adhesive is insufficient, it may cause deformation of the composite layer at high temperatures or a decrease in the bonding strength, affecting the yield.

[0004] Therefore, how to provide an adhesive for composite current collectors that overcomes insufficient thermal stability is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the above information disclosed in this background art section is only used to understand the background art of the concept of this application. Therefore, the above description is not considered as information on the prior art. Summary of the Invention

[0006] The embodiments of the present disclosure at least provide an adhesive for composite current collectors, a preparation method thereof, and a composite current collector.

[0007] In a first aspect, the embodiments of the present disclosure provide a preparation method of an adhesive for composite current collectors, including the following steps: Step S1, dissolve tetrabutyltetraphenylammonium borate in deionized water to prepare a modified solution; Step S2, add hollow silica particles to the modified solution, control the reaction temperature at 70 - 75 °C, and stir to react to obtain pre-modified particles; Step S3, filter to remove the unreacted residues on the surface of the pre-modified particles, wash with deionized water and then dry to obtain modified particles; Step S4, add the modified particles to the acrylic adhesive and stir to obtain the adhesive for composite current collectors.

[0008] In an optional embodiment, the concentration of tetrabutyltetraphenylammonium borate in the modified solution in Step S1 is 10 - 40%.

[0009] In an optional embodiment, the particle size range of the hollow silica particles is 200 - 300 nm.

[0010] In an optional embodiment, the mass ratio of the hollow silica particles, tetrabutyltetraphenylammonium borate, and deionized water in Step S2 is 20 : (10 - 40) : 100.

[0011] In an alternative embodiment, the mass ratio of the modified particles to the acrylic glue in step S4 is 2.2 to 4.6:100.

[0012] In an alternative embodiment, the stirring in step S4 specifically includes: successively performing low-speed stirring and dispersion at 200 rpm for 10 - 30 min, ultrasonic dispersion for 10 - 15 min, and super-homogenization dispersion for 10 - 15 min.

[0013] In a second aspect, the embodiments of the present disclosure further provide a glue for a composite current collector prepared by the method as described above, which includes 100 parts of acrylic glue and 2.2 - 4.6 parts of modified particles by mass.

[0014] In an alternative embodiment, the distribution width of the modified particles in the glue for the composite current collector is 1.2 - 2.5.

[0015] In a third aspect, the embodiments of the present disclosure further provide a composite current collector, including: a PP substrate and a copper foil; wherein, the PP substrate and the copper foil are bonded by the glue for the composite current collector as described above.

[0016] In an alternative embodiment, the peel strength of the composite current collector in an environment of 150°C is not less than 6 N / cm.

[0017] The beneficial effects of the present invention are that the glue for the composite current collector, its preparation method, and the composite current collector form an organic-inorganic hybrid interface by the combination of tetrabutyltetraphenylborate ammonium and the hydroxyl groups on the surface of hollow silica particles. The benzene rings and boric acid groups in its molecular structure can provide thermal stability, and cooperate with the heat resistance of silica itself to form a synergistic effect to improve the high-temperature tolerance of the glue system; in addition, the organic part of tetrabutyltetraphenylborate ammonium can form hydrogen bonds with the polar groups in the acrylic resin, enhancing the interfacial bonding force with the matrix and achieving the high-temperature resistance effect of the composite current collector.

[0018] Other features and advantages of the present invention will be described in the following description, and, in part, will be obvious from the description, or will be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the description.

[0019] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given for detailed description as follows. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following provides a clear and complete description of the technical solutions of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0021] As used herein, phrases such as "in one embodiment", "according to one embodiment", "in some embodiments", etc. generally refer to the fact that the specific feature, structure, or characteristic after such a phrase can be included in at least one embodiment of the present disclosure. Therefore, a specific feature, structure, or characteristic can be included in more than one embodiment of the present disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, terms such as "example", "exemplary", etc. are used "as an example, instance, or illustration. Any embodiment, aspect, or design described herein as "example" or "exemplary" is not necessarily construed as being preferred or superior to other embodiments, aspects, or designs. Instead, the use of terms such as "example", "exemplary", etc. is intended to present concepts in a specific manner.

[0022] As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0023] The terms used herein are only for describing specific exemplary configurations and are not intended to be limiting. As used herein, the singular articles "a", "an", and "the" may also be intended to include the plural forms, unless clearly stated otherwise herein. The terms "comprising", "including", and "having" are inclusive, and thus specify the presence of the specified features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or their combinations. The method steps, processes, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or shown, unless specifically identified as the order of execution. Additional or alternative steps may be employed.

[0024] The following provides a detailed description of some embodiments of the present invention. Without conflict, the following embodiments and the features in the embodiments may be combined with each other.

[0025] An embodiment of the present disclosure provides a method for preparing a glue for a composite current collector, including the following steps: Step S1, dissolve tetrabutyltetraphenylammonium borate in deionized water to obtain a modified solution; Step S2, add hollow silica particles to the modified solution, control the reaction temperature at 70 - 75 °C, and stir and react for 1 - 1.5 h to obtain pre-modified particles; Step S3, filter to remove the unreacted reaction residues on the surface of the pre-modified particles, wash with deionized water, and dry at 90 - 95 °C to obtain modified particles; Step S4, add the modified particles to acrylic glue and stir for 0.5 - 1 h to obtain the glue for a composite current collector.

[0026] In some embodiments, specifically, the concentration of tetrabutyltetraphenylammonium borate in the modified solution in Step S1 is 10 - 40%.

[0027] In some embodiments, specifically, the particle size range of the hollow silica particles is 200 - 300 nm.

[0028] Specifically, hollow silica spherical particles (HSP) have an extremely high specific surface area and good chemical stability. After modification, their surface is rich in hydroxyl groups, which can form hydrogen bonds or other types of physicochemical bonds with polymer substrates and metal surfaces. This kind of bonding not only strengthens the physical adhesion between the metal and the polymer substrate, but also improves the overall bonding strength through chemical bonding.

[0029] Specifically, the addition of hollow silica spherical particles (HSP) can improve the tensile strength and toughness of the glue. The nanoparticles have good dispersibility and can be evenly distributed in the glue to form reinforcement points, enabling the glue to have higher fracture resistance when stressed and better disperse external stress to avoid local damage.

[0030] Specifically, hollow silica spherical particles (HSP), as a chemically inert filler, can improve the tolerance of the glue in harsh environments, including high temperature, humidity, and corrosive chemicals. Due to its excellent stability, the silica particles can protect the glue to maintain long-term bonding performance in high-temperature or corrosive environments and extend its service life.

[0031] In some embodiments, specifically, the mass ratio of the hollow silica particles, tetrabutyltetraphenylammonium borate, and deionized water in Step S2 is 20:(10 - 40):100.

[0032] In some embodiments, specifically, the mass ratio of the modified particles to acrylic glue in Step S4 is 2.2 - 4.6:100.

[0033] In some embodiments, specifically, the stirring in step S4 specifically includes: sequentially performing low-speed stirring and dispersion at 200 rpm for 10 - 30 min, ultrasonic dispersion for 10 - 15 min, and superhomogenization dispersion for 10 - 15 min.

[0034] The embodiments of the present disclosure further provide a glue for a composite current collector prepared by the method as described above, which includes 100 parts of acrylic glue and 2.2 - 4.6 parts of modified particles by mass.

[0035] The embodiments of the present disclosure further provide a composite current collector, including: a PP substrate and a copper foil; wherein, the PP substrate and the copper foil are bonded by the glue for a composite current collector as described above.

[0036] Example 1

[0037] Step S1, solution preparation: Dissolve tetrabutyltetraphenylborate ammonium, a modifying substance, in deionized water to prepare a solution with a concentration of 20%.

[0038] Step S2, particle addition and reaction: Add 20 grams of hollow silica particles (200 nm) to 100 grams of the modified solution, control the temperature at 70 °C, and the stirring reaction time is 1.5 hours.

[0039] Step S3, post-treatment: After the reaction, remove the unreacted modifying substance by filtration, wash the particles with deionized water, and finally dry them at 95 °C to obtain modified particles.

[0040] Step S4, add 2 grams of the modified particles to 100 grams of acrylic glue and stir at 200 rpm for 30 minutes.

[0041] Step S5, adhesion test: Coat the glue on the PP substrate with a thickness of 10 μm, dry it, laminate it with the copper foil, and test the 180° peel strength in an environment of 150 °C.

[0042] Specifically, the test results of Example 1 are shown in Table 1 below.

[0043] Table 1

[0044] Number Additive Glue peel strength (N / cm) 1 Without adding silica 2.5 2 / 2.6 3 Tetrabutyltetraphenylammonium borate 4.2 4 KH570 3.0 5 KH560 3.2

[0045] Specifically, the HSP particles modified with tetrabutyltetraphenylborate ammonium significantly improve the adhesion of the glue. Compared with the untreated HSP particles, the adhesion is increased by 68%. This indicates that the surface modification of tetrabutyltetraphenylborate ammonium effectively improves the binding force between the HSP particles and the glue substrate.

[0046] Example 2

[0047] Step S1, Solution Preparation: Dissolve the modified substance tetrabutyltetraphenylammonium borate in deionized water to prepare a 20% concentration solution;

[0048] Step S2, Particle Addition and Reaction: Add 20 grams of hollow silica particles (200 nm) to 100 grams of the solution, control the temperature at 70 °C, and stir for 1.5 hours;

[0049] Step S3, Post-treatment: After the reaction, filter to remove the unreacted modified substance, wash the particles with deionized water, and finally dry at 95 °C to obtain modified particles;

[0050] Step S4, Add 2 grams of the modified particles to 100 grams of acrylic glue and stir to disperse;

[0051] Step S5, Adhesion Test: Coat the glue on a PP substrate with a thickness of 10 μm, dry it, laminate it with copper foil, and test the 180° peel strength at 150 °C.

[0052] Among them, step S4 of stirring and dispersing is carried out by three methods:

[0053] Method 1: Conduct preliminary dispersion at a stirring speed of 200 rpm for 30 minutes

[0054] Method 2: Conduct preliminary dispersion at a stirring speed of 200 rpm for 15 minutes, and then sonicate for 15 minutes.

[0055] Method 3: Conduct preliminary dispersion at a stirring speed of 200 rpm for 10 minutes, then sonicate for 10 minutes, and perform superhomogeneous dispersion for 10 minutes.

[0056] Specifically, the test results of Example 2 are shown in Table 2 below.

[0057] Table 2

[0058]

[0059] Specifically, the average particle size of the HSP particles in single-stage dispersion is 450 nm, indicating that the particles are relatively large and the dispersion effect is poor. The two-stage dispersion method reduces the average particle size to 270 nm, showing a certain improvement, but there are still large differences in particle size. The multi-stage dispersion method further reduces the average particle size to 210 nm, and the particle size uniformity is significantly improved. The glue peel strength is significantly increased from 4.2 to 7.1.

[0060] Specifically, compared with single-stage and two-stage dispersion methods, the multi-stage dispersion technology can more effectively reduce the average particle size of HSP particles and significantly narrow the particle distribution width (SPAN), thereby ensuring the uniform distribution of particles in the matrix and improving the glue peel strength.

[0061] Example 3

[0062] Step S1, solution preparation: Dissolve the modified substance tetrabutyltetraphenylammonium borate in deionized water to prepare a solution with a concentration of 20%.

[0063] Step S2, particle addition and reaction: Add 20 grams of silica particles to 100 grams of the modified solution, control the temperature at 70°C, and stir for 1.5 hours.

[0064] Step S3, post-treatment: After the reaction, filter to remove the unreacted modified substance, wash the particles with deionized water, and finally dry at 95°C to obtain modified particles.

[0065] Step S4, add 2 grams of the modified particles to 100 grams of acrylic glue and stir to disperse.

[0066] Step S5, adhesion test: Coat the glue on a PP substrate with a thickness of 10 μm, dry it, laminate it with copper foil, and test the 180° peel strength at 150°C.

[0067] Among them, in step S2, hollow silica and solid silica with different particle sizes are selected for comparison.

[0068] Specifically, the test results of Example 3 are shown in Table 3 below.

[0069] Table 3

[0070]

[0071] Specifically, after testing, hollow silica particles with a particle size in the range of 200 - 300 nm showed the best adhesion and dispersibility. Smaller particles (<200 nm) can provide a larger specific surface area, but due to their high surface energy, they are prone to aggregation, resulting in poor dispersibility. At the same time, they easily interact with the glue, reducing the wetting effect of the glue on the substrate and causing a decrease in the peel strength. Larger particles (>300 nm) have a larger particle size and partially act as an isolation layer from the substrate, resulting in a decrease in the peel strength. Solid silica has a high density and is prone to sedimentation, with poor dispersion effect and a decrease in the peel strength.

[0072] Therefore, in this example, the optimal particle size range of the hollow silica particles is specified as 200 - 300 nm.

[0073] Example 4

[0074] Step S1, solution preparation: Dissolve the modified substance tetrabutyltetraphenylammonium borate in deionized water to prepare a solution with a concentration of X%.

[0075] Step S2, addition and reaction of 200 - 300 nm particles: Add 20 grams of silica particles to 100 grams of the modified solution, control the temperature at 70 °C, and stir for 1.5 hours for the reaction;

[0076] Step S3, post-treatment: After the reaction, filter to remove the unreacted modified substances, wash the particles with deionized water, and finally dry at 95 °C to obtain the modified particles;

[0077] Step S4, add 2 grams of the modified particles to 100 grams of acrylic glue and stir to disperse;

[0078] Step S5, adhesion test: Coat the glue on the PP substrate with a thickness of 10 μm, dry it, laminate it with copper foil, and test the 180° peel strength at 150 °C.

[0079] Specifically, the test results of Example 4 are shown in Table 4 below.

[0080] Table 4

[0081] Number X Peel strength (N / cm) 1 0 2.1 2 5 3.5 3 10 6.6 4 20 7.1 5 30 6.9 6 40 6.2

[0082] Specifically, when X = 20, the peel strength of the glue is the best. If it continues to increase, since tetrabutyltetraphenylammonium borate is a small molecule, the excessive tetrabutyltetraphenylammonium borate will penetrate between the polymer chains of the glue molecules, affecting the bonding force between the glue bodies, so the peel strength decreases.

[0083] Example 5

[0084] Step S1, solution preparation: Dissolve the modified substance tetrabutyltetraphenylammonium borate in deionized water to prepare a solution with a concentration of 20%;

[0085] Step S2, addition and reaction of particles: Add 20 grams of silica particles to 100 grams of the modified solution, control the temperature at 70 °C, and stir for 1.5 hours for the reaction;

[0086] Step S3, post-treatment: After the reaction, filter to remove the unreacted modified substances, wash the particles with deionized water, and finally dry at 95 °C to obtain the modified particles;

[0087] Step S4, add the modified particles to 100 grams of acrylic glue and stir to disperse;

[0088] Step S5, adhesion test: Coat the glue on the PP substrate with a thickness of 10 μm, dry it, laminate it with copper foil, and test the 180° peel strength at 150 °C.

[0089] Among them, after determining that the optimal particle size range is 200 - 300 nm, the addition amount of the modified particles in step S4 is adjusted and compared.

[0090] Specifically, the test results of Example 5 are shown in Table 5 below.

[0091] Table 5

[0092] Number HSP dosage (%) Adhesion strength (N / cm) 1 1 6.2 2 2.2 7.3 3 3.4 9.1 4 4.6 8.5 5 5.8 6.8

[0093] Specifically, according to the experimental data, it can be seen that the performance of the glue reaches the best when the dosage of HSP particles is 3.4%, and the peel strength (9.1 N / cm) is the best. When the dosage of HSP particles is 5.8%, the performance drops significantly, indicating that too many particles will cause the peel strength of the glue to decrease.

[0094] In summary, for the glue for the composite current collector, its preparation method, and the composite current collector, tetrabutyltetraphenylammonium borate combines with the hydroxyl groups on the surface of hollow silica particles to form an organic-inorganic hybrid interface. The benzene rings and boric acid groups in its molecular structure can provide thermal stability, and cooperate with the heat resistance of silica itself to form a synergistic effect to improve the high-temperature tolerance of the glue system; in addition, the organic part of tetrabutyltetraphenylammonium borate can form hydrogen bonds with the polar groups in the acrylic resin, enhancing the interfacial bonding force with the matrix and achieving the high-temperature resistance effect of the composite current collector.

[0095] Taking the above ideal embodiments based on the present invention as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A preparation method of glue for a composite current collector, characterized in that, It includes the following steps: Step S1: Dissolve tetrabutyltetraphenylammonium borate in deionized water to prepare a modified solution; Step S2: Add hollow silica particles into the modified solution, control the reaction temperature at 70 - 75 °C, and stir to obtain pre-modified particles; Step S3: Filter to remove the unreacted residues on the surface of the pre-modified particles, wash with deionized water and then dry to obtain modified particles; Step S4: Add the modified particles to acrylic glue and stir to obtain the glue for composite current collector.

2. The preparation method according to claim 1, characterized in that in step S1, the concentration of tetrabutyltetraphenylammonium borate in the modified solution is 10 - 40%.

3. The preparation method according to claim 1, characterized in that the particle size range of the hollow silica particles is 200 - 300 nm.

4. The preparation method according to claim 1, characterized in that the mass ratio of the hollow silica particles, tetrabutyltetraphenylammonium borate and deionized water in step S2 is 20:(10 - 40):

100.

5. The preparation method according to claim 1, characterized in that in step S4, the mass ratio of the modified particles to acrylic glue is 2.2 - 4.6:

100.

6. The preparation method according to claim 1, characterized in that the stirring in step S4 specifically includes: sequentially performing low-speed stirring and dispersion at 200 rpm for 10 - 30 min, ultrasonic dispersion for 10 - 15 min, and superhomogenization dispersion for 10 - 15 min.

7. A glue for composite current collector prepared by the method according to any one of claims 1 - 6, characterized in that it includes 100 parts of acrylic glue and 2.2 - 4.6 parts of modified particles by mass.

8. The glue for composite current collector according to claim 7, characterized in that the distribution width of the modified particles in the glue for composite current collector is 1.2 - 2.

5.

9. A composite current collector, characterized in that, It includes: PP substrate and copper foil; wherein, the PP substrate and the copper foil are bonded with the glue for composite current collector according to claim 7.

10. The composite current collector according to claim 9, characterized in that the peeling force of the composite current collector is not less than 6 N / cm at 150 °C.

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