Adhesive material, adhesive composition, positive electrode plate, secondary battery, and power consumption device

Abstract

The present invention provides an adhesive material, an adhesive composition, a positive electrode plate, a secondary battery, and a power consumption device. The adhesive material and adhesive include the adhesive comprising structural units A, B, C, and D, wherein at least some of the structural units A are crosslinked with at least some of the structural units D, and the structural units A are represented by formula (1), wherein the structural units B are each independently one or more of formula (2), formula (3), formula (4), formula (5), or formula (6), the structural units C are each independently one or more of formula (7) or formula (8), each m1 and each m2 is independently an integer from 1 to 20, the structural units D are each independently one or more of formula (9), and each n1 is independently an integer from 1 to 20. JPEG2026501212000078.jpg110168

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to Chinese Patent Application No. 202311027156.4, proposed on August 15, 2023, with the title "Adhesive material, adhesive composition, positive electrode plate, secondary battery and power consumption device," the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the field of battery technology, and in particular to an adhesive material, an adhesive composition, a positive electrode plate, a secondary battery, and a power consuming device. [Background technology]

[0003] Secondary-ion batteries (e.g., lithium-ion secondary batteries or sodium-ion secondary batteries) are new energy batteries with advantages such as high operating voltage, high specific capacity, long charge / discharge life, and no memory effect. At the same time, the safety of secondary-ion batteries is also attracting increasing attention. During the routine secondary-ion battery manufacturing process, abnormal battery cores have been observed, such as zero resistance in assembly short-circuit tests, low formation voltage, high self-discharge, and large module pressure differences. When the finished battery was disassembled, it was discovered that the separator corresponding to the edge margin of the positive electrode plate in the battery core had been damaged. Analysis of the cause revealed that metal particles were sputtered into the margin during the laser cutting process, causing the separator to be damaged. In light cases, this could increase the pressure difference in the battery core, and in severe cases, it could lead to a short circuit and serious accidents. Furthermore, when the battery core is inserted into the shell, the tabs may bend, causing the base of the tab to come into contact with the edge margin of the positive electrode plate, resulting in a short circuit.

[0004] To solve the above problem, an insulating adhesive layer is provided on the edge of the positive electrode plate of the battery core, which is very helpful in avoiding the occurrence of the above short circuit problem. Summary of the Invention

[0005] The present application provides an adhesive material, an adhesive composition, a positive electrode plate, a secondary battery, and a power consumption device to solve the problem of poor abrasion resistance of the edge insulating adhesive layer of the positive electrode plate.

[0006] A first aspect of the present application provides an adhesive substance, the adhesive substance comprising a pressure-sensitive adhesive. The pressure-sensitive adhesive comprises structural units A, B, C, and D, and at least a portion of the structural units A is crosslinked with at least a portion of the structural units D. Here, the structural units A are JPEG2026501212000002.jpg35130. The structural unit B is independently JPEG2026501212000003.jpg30130JPEG2026501212000004.jpg30130JPEG2026501212000005.jpg41130JPEG2026501212000006.jpg30130or JPEG2026501212000007.jpg30130, and optionally, the structural unit B is JPEG2026501212000008.jpg30130 or JPEG2026501212000009.jpg30130. Each structural unit C is independently JPEG2026501212000010.jpg41130 or JPEG2026501212000011.jpg41130, wherein each m1 and each m2 is independently an integer from 1 to 20, and optionally, each m1 is independently an integer from 2 to 12, and each m2 is independently an integer from 8 to 12. JPEG2026501212000012.jpg41130, and n1 is independently any integer from 1 to 20, and optionally, n1 is independently any integer from 1 to 12, and further optionally, n1 is independently any integer from 1 to 6.

[0007] The structural unit B is provided by an acrylonitrile monomer. This monomer is a hard monomer that can reinforce the strength of the insulating adhesive layer. The structural unit C is provided by an acrylate-based monomer. The acrylate-based monomer is a soft monomer that can improve the flexibility of the insulating adhesive layer and reinforce the adhesive strength between the insulating adhesive layer and the current collector.

[0008] The structural units A and D form a three-dimensional crosslinked network through hydrogen-bonding interactions. The resulting insulating adhesive layer has excellent abrasion resistance and effectively isolates the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell. This effectively prevents short circuits between the tab and the positive electrode film layer. Meanwhile, the structural units A, C, and D are all acrylic acid-based monomers. Because acrylic acid-based materials are resistant to high temperatures and decomposition, the resulting insulating adhesive layer prevents the positive electrode plate current collector from being directly cut by a laser and effectively resists metal particle scattering. Furthermore, laser cutting in the insulating adhesive layer reduces the generation of molten metal bead particles. This effectively mitigates the problem of metal particle scattering that occurs when the laser directly cuts the current collector and damages the separator. The three-dimensional crosslinked network also further reinforces the resistance to laser cutting, providing better protection for the separator.

[0009] In any embodiment of the first aspect of the present application, at least some of the structural units A, at least some of the structural units B, at least some of the structural units C, and at least some of the structural units D are connected in a chain to form a first chain structure. At least some of the structural units A, at least some of the structural units C, and at least some of the structural units D are connected in a chain to form a second chain structure. The structural units A in at least some of the first chain structures are crosslinked with the structural units D in at least some of the second chain structures. The structural units D in at least some of the first chain structures are crosslinked with the structural units A in at least some of the second chain structures.

[0010] The first chain structure and the second chain structure simultaneously contain the structural unit A and the structural unit D, which provides more sites for crosslinking between the structural unit A and the structural unit D, thereby further improving the density of the three-dimensional network formed and better improving the abrasion resistance of the adhesive. The first chain structure simultaneously contains the structural unit A, the structural unit B, the structural unit C, and the structural unit D, and is more advantageous for adjusting and controlling the strength provided by this chain structure by utilizing the contents of the structural unit B and the structural unit C. On the other hand, the second chain structure simultaneously contains the structural unit A, the structural unit C, and the structural unit D, and is more flexible, which can be utilized to more flexibly adjust the content of the structural unit C, and further flexibly adjust the adhesive strength of the adhesive.

[0011] In any embodiment of the first aspect of the present application, the adhesive substance satisfies one or more of the following conditions 1) to 4): 1) The abrasion resistance of an insulating adhesive layer formed from the adhesive substance and having a thickness of 3 μm to 7 μm is tested using an RCA paper tape abrasion resistance tester, where a 55 g weight is used to run the test piece 300 mm twice on a flat surface to form an experimental area, and n test points are taken in the experimental area, with a test point pitch of 2 cm or more, and the proportion of non-leakage points in the experimental area is 30% or more, where 5≦n≦100, or the area of ​​the non-leakage points in the experimental area is 60% or more of the total area of ​​the experimental area. 2) The cohesive strength of the insulating adhesive layer formed from the adhesive substance is 620 N / m to 750 N / m, optionally 660 N / m to 725 N / m. 3) The Shore hardness of the insulating adhesive layer formed from the adhesive substance is 45 HA to 80 HA, optionally 50 HA to 65 HA. and 4) the adhesive strength of the insulating adhesive layer formed by the adhesive substance is 30 N / m to 90 N / m, and optionally 40 N / m to 80 N / m.

[0012] In any embodiment of the first aspect of the present application, the molar ratio of structural unit D to structural unit A in the adhesive is 0.5:1 to 5:1, optionally 0.5:1 to 3:1, and further optionally 1:1 to 3:1. Optionally, the molar content of structural unit A is 4% to 50%, optionally 4% to 10%. Optionally, the molar content of structural unit D is 1% to 50%, optionally 5% to 30%, and further optionally 5% to 15%. This maximizes crosslinking between structural unit A and structural unit D, improving the abrasion resistance of the insulating adhesive layer formed by the adhesive substance.

[0013] In any embodiment of the first aspect of the present application, the molar ratio of structural unit C to structural unit B in the adhesive is 1:1 to 300:1, and optionally 5:1 to 50:1. Optionally, the molar content of structural unit B is 0.2% to 20%, and optionally 1% to 5%. Optionally, the molar content of structural unit C is 1% to 90%, and optionally 55% to 90%, and further optionally 75% to 80%. By utilizing the above-described ratio control of structural unit B to structural unit C, the adhesive strength of the adhesive substance is improved as much as possible.

[0014] In any embodiment of the first aspect of the present application, the adhesive substance further comprises an insulating filler and / or a dispersing agent, and the carboxyl groups in the adhesive substance can form hydrogen bonds with the insulating filler to improve the adhesive strength of the resulting insulating adhesive layer.

[0015] In one embodiment of the first aspect of the present application, the weight ratio of the insulating filler, adhesive, and dispersant is (70-90):(10-25):0.4. The use of the insulating filler can reduce costs. In addition, the dispersant can improve the dispersion effect of the insulating filler in the adhesive, prevent subsequent crosslinking of the adhesive, and provide a sufficient adhesive strength.

[0016] In one embodiment of the first aspect of the present application, the insulating filler comprises one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder. The hardness of each of the insulating fillers varies, with boehmite having a more suitable hardness. This is because it can improve the stability of the insulating adhesive layer and its hardness does not adversely affect the battery separator.

[0017] In any embodiment of the first aspect of the present application, the insulating filler has a volume average particle size of D V50≦1 μm. Insulating fillers within this particle size range can be completely embedded in insulating layers of normal thickness, thereby effectively controlling the friction of the insulating fillers against the separator.

[0018] In any embodiment of the first aspect of the present application, the adhesive further comprises a solvent, and optionally the solids content of the adhesive is 20% to 40%. Optionally, the solvent of the adhesive comprises water. Optionally, the viscosity of the adhesive measured at 25°C and 12 rpm is 350 mPa·s to 900 mPa·s.

[0019] A second aspect of the present application provides a pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive, the pressure-sensitive adhesive comprising a first pressure-sensitive adhesive and a second pressure-sensitive adhesive. The first pressure-sensitive adhesive is a polymer and comprises structural units A, B, C, and D. The second pressure-sensitive adhesive is a polymer and comprises structural units A, C, and D. Here, structural unit A is JPEG2026501212000013.jpg35130, and the structural unit B is independently JPEG2026501212000014.jpg30130JPEG2026501212000015.jpg30130JPEG2026501212000016.jpg41130JPEG2026501212000017.jpg30130or JPEG2026501212000018.jpg30130, and optionally, the structural unit B is JPEG2026501212000019.jpg30130 or JPEG2026501212000020.jpg30130. The structural unit C of the first adhesive and the structural unit C of the second adhesive are each independently JPEG2026501212000021.jpg41130 or JPEG2026501212000022.jpg41130, and each m1 and each m2 is independently any integer from 1 to 20. For example, m1 is 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18, or 20, and m2 is 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18, or 20. Alternatively, each m1 is independently any integer from 2 to 12, and each m2 is independently any integer from 8 to 12. The structural unit D of the first pressure-sensitive adhesive and the structural unit D of the second pressure-sensitive adhesive are each independently JPEG2026501212000023.jpg41130, where n1 is independently any integer from 1 to 20, optionally n1 is independently any integer from 1 to 12, and further optionally n1 is independently any integer from 1 to 6.

[0020] When this adhesive composition is used in a positive electrode plate to produce an insulating adhesive layer, the structural unit B in the first adhesive is provided via an acrylonitrile monomer. This monomer is a hard monomer and can reinforce the strength of the insulating adhesive layer. The structural unit C in the first adhesive and the second adhesive is provided by an acrylate monomer. The acrylate monomer is a soft monomer and can improve the flexibility of the insulating adhesive layer and reinforce the adhesive strength between the insulating adhesive layer and the current collector.

[0021] At the same time, the structural unit A in the first adhesive and the structural unit D in the second adhesive, and the structural unit D in the first adhesive and the structural unit A in the second adhesive, form a three-dimensional crosslinked network through hydrogen-bonding interactions. The resulting insulating adhesive layer has excellent abrasion resistance, effectively isolating the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell, and effectively preventing short circuits between the tab and the positive electrode film layer. On the other hand, both the first and second adhesives in this adhesive composition are acrylic acid-based monomers, and the acrylic acid-based material therein is resistant to high temperatures and decomposition. Therefore, the resulting insulating adhesive layer prevents the current collector of the positive electrode plate from being directly cut by a laser and effectively resists the scattering of metal particles. Furthermore, when the insulating adhesive layer is cut by a laser, molten metal bead particles are less likely to be generated, effectively mitigating the problem of metal particles being scattered and damaging the separator when the current collector is directly cut by a laser. At the same time, the three-dimensional crosslinked network also further reinforces the resistance to laser cutting, and provides better protection for the separator.

[0022] In one embodiment of the second aspect, the weight ratio of the first adhesive to the second adhesive is 1:2.5 to 1:20, and optionally 1:5 to 1:17.5. The second adhesive provides the insulating adhesive layer with relatively good adhesion and flexibility, while an appropriate amount of the first adhesive improves the strength of the insulating adhesive layer, thereby better matching the strength of the insulating filler in the adhesive composition and the strength of the positive electrode current collector and allowing the adhesive layer to fully exert its adhesive strength. Furthermore, the weight ratio is used to adjust the crosslinked network density of the insulating adhesive layer, providing sufficient network support for wear resistance and protection of the current collector.

[0023] In one embodiment of the second aspect, the first adhesive satisfies one or more of the following conditions: 1) the molar content of structural unit A in the first adhesive is 5% to 30%, 2) the molar content of structural unit B in the first adhesive is 5% to 85%, 3) the molar content of structural unit C in the first adhesive is 5% to 85%, and 4) the molar content of structural unit D in the first adhesive is 5% to 15%. The hardness of the first adhesive is adjusted by using the contents of structural unit B and structural unit C to meet the hardness requirements for insulating adhesive layers of different designs and processing methods. The contents of structural unit A and structural unit D are relatively low in all structural units, and are mainly used to form a crosslinked network with the second adhesive, while also effectively controlling self-crosslinking of both in the first adhesive.

[0024] In any embodiment of the second aspect, the second adhesive satisfies one or more of the following conditions: 1) the molar content of the structural unit A in the second adhesive is 5% to 10%, 2) the molar content of the structural unit C in the second adhesive is 70% to 85%, and 3) the molar content of the structural unit D in the second adhesive is 5% to 20%. The structural unit C accounts for a major proportion in the second adhesive, thereby providing the second adhesive with sufficient flexibility and adhesive strength. This improves the adhesive strength of the insulating adhesive layer formed from the adhesive composition to the insulating filler and the positive electrode current collector.

[0025] In any embodiment of the second aspect, the weight-average molecular weight of the first adhesive is 500,000 to 1,500,000, and optionally the difference in weight-average molecular weight between the first adhesive and the second adhesive is 100,000 to 1,500,000, which provides a relatively good suspending effect for the insulating filler, effectively preventing sedimentation of the insulating filler, and improving the adhesive strength of the insulating adhesive layer.

[0026] In any embodiment of the second aspect, the adhesive substance further comprises an insulating filler and / or a dispersing agent, and the carboxyl groups of the first adhesive and the second adhesive can form hydrogen bonds with the insulating filler to improve the adhesive strength of the resulting insulating adhesive layer.

[0027] In one embodiment of the second aspect of the present application, the weight ratio of the insulating filler, adhesive, and dispersant is (70-90):(10-25):0.4. The use of the insulating filler can reduce costs. Furthermore, the dispersant not only improves the dispersion effect of the insulating filler in the adhesive, but also prevents subsequent crosslinking of the adhesive, and is a sufficient adhesive agent to provide relatively good adhesive strength.

[0028] In any embodiment of the second aspect, the insulating filler comprises any one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder. Optionally, the volume average particle size of the insulating filler is D V The particle size of the insulating filler is 50 μm or less and 1 μm or less. Insulating fillers within this particle size range can be completely embedded in insulating layers of normal thickness, thereby effectively controlling the friction of the insulating filler against the separator.

[0029] In any embodiment of the second aspect, the dispersant comprises one or more of a polyacrylate-based compound, an aliphatic alcohol polyether-based compound, or a polyether-modified siloxane-based compound.

[0030] In any embodiment of the second aspect, the pressure-sensitive adhesive composition further comprises a solvent. Optionally, the solids content of the pressure-sensitive adhesive composition is 20% to 40%, and further optionally, the solvent of the pressure-sensitive adhesive composition comprises water.

[0031] A third aspect of the present application provides a positive electrode plate, the positive electrode plate including: a positive electrode current collector having a positive electrode film layer region and a bare foil region on at least one side of the positive electrode current collector; a positive electrode film layer disposed on the positive electrode film layer region of the positive electrode current collector; and an insulating adhesive layer disposed on the bare foil region of the positive electrode current collector, the insulating adhesive layer being formed using any one of the adhesive materials of the first aspect or formed by curing any one of the adhesive compositions of the second aspect.

[0032] The insulating adhesive layer has excellent abrasion resistance. Therefore, it effectively isolates the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell, effectively preventing short circuits between the tab and the positive electrode film layer. At the same time, the insulating adhesive layer prevents the current collector of the positive electrode plate from being directly cut by the laser and effectively resists scattering of metal particles. Laser cutting at the insulating adhesive layer reduces the generation of molten metal bead particles, effectively mitigating the problem of scattering metal particles damaging the separator caused by direct laser cutting of the current collector. At the same time, the three-dimensional crosslinked network further reinforces the resistance to laser cutting, providing better protection for the separator.

[0033] In any embodiment of the third aspect, the thickness of the insulating adhesive layer is equal to or less than the thickness of the positive electrode film layer, and optionally the thickness of the insulating adhesive layer is between 3 μm and 7 μm.

[0034] A fourth aspect of the present application provides a method for manufacturing a positive electrode plate, the method comprising the steps of: forming a positive electrode film layer and an insulating adhesive layer on at least one or both sides of a positive electrode current collector; mixing components of any one of the pressure-sensitive adhesive compositions of the first aspect to form an adhesive solution; coating the adhesive solution on a bare foil region of the positive electrode current collector to obtain a preform having the adhesive solution; and heating the preform having the adhesive solution to obtain an insulating adhesive layer, optionally at a heating temperature of 90°C to 120°C, thereby accelerating the removal rate of the solvent therein.

[0035] In any one of the embodiments of the fourth aspect, the process of mixing components of the PSA composition to form an adhesive solution includes: mixing a dispersant in the PSA composition with water to form a first dispersion, optionally with first stirring, a first stirring time of 5 min to 30 min, and a stirring speed of 200 rpm to 400 rpm; mixing the first dispersion with an insulating filler in the PSA composition to form a second dispersion, optionally with second stirring, a second stirring time of 30 min to 120 min, and a stirring speed of 1200 rpm to 1800 rpm; and mixing the second dispersion with a first PSA in the PSA composition to form a third dispersion, optionally with third stirring, a third stirring time of 15 min to 60 min, and a stirring speed of 400 rpm to 700 rpm. and mixing the third dispersion with the second adhesive in the adhesive composition to form an adhesive solution, optionally wherein the mixing is a fourth stirring, the fourth stirring time is 5 minutes to 30 minutes, and the stirring speed is 200 rpm to 400 rpm.

[0036] A fifth aspect of the present application provides a secondary battery including a positive electrode plate, wherein the positive electrode plate includes any one of the positive electrode plates according to the third aspect or a positive electrode plate manufactured by any one of the manufacturing methods according to the fourth aspect.

[0037] A sixth aspect of the present application provides a power consuming device including a secondary battery, wherein the secondary battery includes any one of the secondary batteries according to the fifth aspect above. [Brief explanation of the drawings]

[0038] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings used in the embodiments of the present application, however, the drawings described below are only some embodiments of the present application, and it is obvious to those skilled in the art that other drawings can be obtained based on the drawings without any creative efforts. [Figure 1] FIG. 2 is a side view of a positive electrode plate according to an embodiment of the present application. [Figure 2] 1 is a schematic diagram of a secondary battery according to an embodiment of the present application; [Figure 3] FIG. 3 is an exploded view of the secondary battery shown in FIG. 2 according to the embodiment of the present application. [Figure 4] 1 is a schematic diagram of a battery module according to an embodiment of the present application; [Figure 5] 1 is a schematic diagram of a battery pack according to an embodiment of the present application. [Figure 6] FIG. 6 is an exploded view of the battery pack shown in FIG. 5 according to an embodiment of the present application. [Figure 7] 1 is a schematic diagram of a power consumption device in which a secondary battery according to an embodiment of the present application is used as a power source;

[0039] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0040] The following describes in more detail the embodiments of the present application in conjunction with the drawings and examples. The detailed description of the embodiments and the drawings are for illustrative purposes only to explain the principles of the present application, but are not intended to limit the scope of the present application, and the present application is not limited to the described examples.

[0041] Hereinafter, with reference to the drawings, embodiments specifically disclosing the adhesive material, adhesive composition, positive electrode plate, secondary battery, and power consumption device of the present application will be described in detail. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters and redundant description of actually identical structures may be omitted. This is to avoid the following description becoming unnecessarily long and to facilitate easy understanding by those skilled in the art. Note that the drawings and the following description are provided to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0042] The "ranges" disclosed in this application are defined in the form of lower and upper limits. A given range is defined by selecting one lower limit and one upper limit, and the selected lower and upper limits define the boundaries of the particular range. Such defined ranges may be inclusive or exclusive of the end values, and any combination is possible. That is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also possible. Furthermore, if 1 and 2 are listed as minimum range values ​​and 3, 4, and 5 are listed as maximum range values, the ranges 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 are all possible. In this application, unless otherwise specified, a numerical range "a to b" represents a shorthand notation for any combination of real numbers a to b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that this specification has already listed all real numbers between "0-5," and "0-5" is merely a shorthand representation of combinations of these numbers. Also, expressing a parameter as an integer ≧2 is equivalent to disclosing that this parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0043] Unless otherwise stated, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0044] Unless otherwise stated, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0045] Unless otherwise specified, all steps in this application may be performed in order or randomly, and are preferably performed in order. For example, when the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed in order, or steps (b) and (a) performed in order. For example, when the method mentioned above may further include step (c), it means that step (c) may be added to the method in any order, and for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0046] Unless otherwise stated, the terms "comprise" and "include" referred to in this application are open-ended, i.e., the terms "comprise" and "include" may further include or encompass other components not listed.

[0047] Unless otherwise stated, in this application, the term "or" is inclusive. For example, the following conditions satisfy "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) but B is true (or exists); and both A and B are true (or exist).

[0048] [Adhesive substance] Since secondary ion batteries cannot avoid vibrations during operation, the tabs in the battery core also move relative to each other when vibrations occur, resulting in internal friction. However, the wear resistance of typical insulating adhesive layers is insufficient, and the relative movement of the tabs can cause coating wear and foil leakage from the electrodes, resulting in short circuits inside the battery core.

[0049] In order to solve the above problems, a first embodiment of the present application provides an adhesive substance. The adhesive substance includes an adhesive agent, and the adhesive agent includes structural units A, B, C, and D. At least a portion of the structural units A is crosslinked with at least a portion of the structural units D. Here, the structural units A are JPEG2026501212000024.jpg35130. The structural unit B is independently JPEG2026501212000025.jpg30130JPEG2026501212000026.jpg30130JPEG2026501212000027.jpg41130JPEG2026501212000028.jpg30130or JPEG2026501212000029.jpg30130, and optionally, the structural unit B is JPEG2026501212000030.jpg30130 or JPEG2026501212000031.jpg30130. Each structural unit C is independently JPEG2026501212000032.jpg41130 or JPEG2026501212000033.jpg41130, wherein each m1 and each m2 is independently an integer from 1 to 20, and optionally, each m1 is independently an integer from 2 to 12, and each m2 is independently an integer from 8 to 12. JPEG2026501212000034.jpg41130, and n1 is independently any integer from 1 to 20, and optionally, n1 is independently any integer from 1 to 12, and further optionally, n1 is independently any integer from 1 to 6.

[0050] In the adhesive of the above-mentioned adhesive substance, the structural unit B is provided via an acrylonitrile monomer. This monomer is a hard monomer and can reinforce the strength of the insulating adhesive layer. The structural unit C is provided by an acrylate-based monomer. The acrylate-based monomer is a soft monomer and can improve the flexibility of the insulating adhesive layer and reinforce the adhesive strength between the insulating adhesive layer and the current collector.

[0051] At the same time, the structural units A and D form a three-dimensional crosslinked network through hydrogen-bonding interactions. The resulting insulating adhesive layer has excellent abrasion resistance and effectively isolates the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell. This effectively prevents short circuits between the tab and the positive electrode film layer. Meanwhile, the structural units A, C, and D are all acrylic acid-based monomers. Because the acrylic acid-based materials are resistant to high temperatures and are resistant to decomposition, the resulting insulating adhesive layer prevents the positive electrode current collector from being directly cut by a laser and effectively resists metal particle scattering. Furthermore, laser cutting in the insulating adhesive layer reduces the generation of molten metal bead particles, effectively mitigating the problem of metal particle scattering that occurs when the current collector is directly cut by a laser and damages the separator. The three-dimensional crosslinked network also further reinforces the resistance to laser cutting, providing better protection for the separator.

[0052] In some embodiments, at least some of the structural units A, at least some of the structural units B, at least some of the structural units C, and at least some of the structural units D are connected in a chain to form a first chain structure. At least some of the structural units A, at least some of the structural units C, and at least some of the structural units D are connected in a chain to form a second chain structure. The structural units A in at least some of the first chain structures are crosslinked with the structural units D in at least some of the second chain structures. The structural units D in at least some of the first chain structures are crosslinked with the structural units A in at least some of the second chain structures.

[0053] The first chain structure and the second chain structure simultaneously contain the structural unit A and the structural unit D. By providing more sites for crosslinking between the structural unit A and the structural unit D, the density of the three-dimensional network formed is further improved, and the abrasion resistance of the adhesive substance is further improved. The first chain structure simultaneously contains the structural unit A, the structural unit B, the structural unit C, and the structural unit D, and is more advantageous for adjusting and controlling the strength provided by this chain structure by utilizing the contents of the structural units B and C. On the other hand, the second chain structure simultaneously contains the structural unit A, the structural unit C, and the structural unit D, and is more flexible, which can be utilized to more flexibly adjust the content of the structural unit C, and further flexibly adjust the adhesive strength of the adhesive substance.

[0054] In some embodiments of the present application, the adhesive material satisfies one or more of the following conditions 1) to 4): 1) The abrasion resistance of a 5 μm-thick insulating adhesive layer formed by the adhesive material is tested using an RCA paper tape abrasion tester, with a 55 g weight running 300 mm twice on a flat surface to form an experimental area, with n test points taken on the experimental area, with a test point pitch of 2 cm or more, and the proportion of non-leakage points in the experimental area being 30% or more, where 5≦n≦100, or the area of ​​the non-leakage points in the experimental area being 60% or more of the total area of ​​the experimental area. 2) The cohesive strength of the insulating adhesive layer formed by the adhesive material is 620 N / m to 750 N / m, optionally 660 N / m to 725 N / m. 3) The Shore hardness of the insulating adhesive layer formed by the adhesive material is 45 HA to 80 HA, optionally 50 HA to 65 HA. and 4) the adhesive strength of the insulating adhesive layer formed by the adhesive substance is 30 N / m to 90 N / m, and optionally 40 N / m to 80 N / m.

[0055] The cohesive strength test method is as follows.

[0056] The adhesive was prepared as a slurry and then coated onto the carbon coating layer of carbon-coated copper foil. After drying, a sample sheet was obtained. One side of the sample sheet was the copper foil surface, and the other side was the adhesive layer formed by the adhesive. The sample sheet was then cut into strips measuring 2 cm wide and 6 cm long, and the copper foil side of the strip was attached to the surface of a hard substrate (steel plate) using 3M-55230H double-sided tape (careful not to create any air bubbles during the attachment process). 3M-55230H double-sided tape was then attached to the adhesive layer side of the fixed strip, and copper foil of the same size as the double-sided tape was covered on the surface of the double-sided tape (careful not to create any air bubbles during the attachment process). The size of the double-sided tape used was the same for both applications. This process yielded a test sample.

[0057] The copper foil and double-sided tape at the first end of the test sample were manually peeled off in a 180° direction, leaving the entire test sample 1 cm behind the opposite end of the first end (i.e., the second end). The first end (hard substrate, carbon-coated copper foil, adhesive layer) was fixed using a jig on one end of the tensile tester, and the second end was fixed using a jig on the other end of the tensile tester.

[0058] The test is performed by setting the tensile speed of the tensile tester to 50 mm / min and the test tensile length to 100 mm. The peel force data obtained from the test is the cohesive strength of the coating material.

[0059] The hardness test method is as follows: A Shore A hardness tester is used to test the hardness of the insulating adhesive layer surface.

[0060] The adhesive strength was tested as follows.

[0061] Specifically, a positive electrode plate with a good appearance is prepared for testing. Products with poor appearance are not acceptable. A 20 mm wide, 100-160 mm long sample of the positive electrode plate with the insulating adhesive layer is cut using a blade. Nitto No. 5000NS special double-sided tape is applied to a steel plate, and a 10 mm wide, 90-150 mm long paper tape, the same width as the sample but 80-200 mm longer than the sample, is attached to the double-sided tape. Wrinkle-removing tape is then placed on top of the paper tape, and the cut sample of the specified size is attached to the wrinkle-removing tape. With the insulating adhesive layer facing down, the sample surface is rolled three times in the same direction with a 3 kg press roller to obtain the test sample. The test sample is fixed on the testing machine, and the end of the steel plate without the electrode plate attached is fixed with the lower jig. The paper tape is folded upward and fixed with the upper jig, aligning the axial direction of the sample with the direction of force application. The tester loads the specimen at a peel rate of 10 mm / min until it breaks, then stops the test and calculates the peel strength f1 (unit: N / m) according to the formula f1 = F / L, where F (unit: N) is the maximum load force and L = 20 mm. The peel strength is the adhesive strength.

[0062] In some embodiments of the present application, the molar ratio of structural unit D to structural unit A in the PSA is 0.5:1 to 5:1, for example, 0.5:1, 1:1, 1.1:1, 2:1, 2.1:1, 2.2:1, 2.5:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.2:1, 3.5:1, 3.8:1, 4:1, 4.5:1, or 5:1, optionally 0.5:1 to 3:1, and more optionally 1:1 to 3:1. Preferably, the molar content of structural unit A is 4% to 50%, for example, 4%, 4.5%, 4.8%, 5%, 5.3%, 5.5%, 6%, 6.2%, 6.4%, 6.8%, 7%, 10%, 15%, 20%, 30%, 40%, or 50%, and more preferably, 4% to 10%. The molar content of structural unit D is 1% to 50%, for example, 1%, 4%, 5%, 6%, 8%, 10%, 13%, 14%, 15%, 20%, 30%, 40%, or 50%, and more preferably, 5% to 30%, and even more preferably, 5% to 15%. This maximizes crosslinking between structural unit A and structural unit D, improving the abrasion resistance of the insulating adhesive layer formed by the adhesive substance.

[0063] In some embodiments of the present application, the molar ratio of structural unit C to structural unit B in the pressure-sensitive adhesive is 1:1 to 300:1, for example, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 60:1, 100:1, 150:1, 200:1, 250:1, 280:1, 290:1, or 300:1, and optionally 5:1 to 50:1. The molar content of structural unit B is 0.2% to 20%, for example, 0.2%, 0.25%, 0.5%, 1%, 1.5%, 2%, 2.1%, 2.5%, 3%, 3.5%, 5%, 10%, 11%, 13%, 15%, or 20%, and optionally 1% to 5%. Optionally, the molar content of structural unit C is 1% to 90%, for example, 5%, 10%, 20%, 30%, 40%, 45%, 50%, 55%, 58%, 60%, 68%, 70%, 75%, 77%, 78%, 80%, 85%, or 90%, and optionally 55% to 90%, and even more optionally 75% to 80%. By controlling the ratio of structural unit B and structural unit C, the adhesive strength of the adhesive substance can be improved as much as possible.

[0064] In some embodiments of the present application, the adhesive further comprises an insulating filler and / or a dispersant. The use of the insulating filler reduces costs, and the dispersant promotes the dispersion of the insulating filler in the adhesive. The carboxyl group of the structural unit A can form hydrogen bonds with the insulating filler to improve the adhesive strength of the resulting insulating adhesive layer.

[0065] In some embodiments of the present application, the ratio of insulating filler, adhesive, and dispersant can be determined based on the composition of a typical adhesive. In some embodiments, the weight ratio of insulating filler, adhesive, and dispersant is (70-90):(10-25):0.4. The use of insulating filler can reduce costs. Furthermore, the dispersant not only improves the dispersion effect of insulating filler in the adhesive, but also prevents subsequent crosslinking of the adhesive, and provides sufficient adhesive strength to provide relatively good adhesion.

[0066] The insulating filler may be an insulating filler commonly used in adhesives. Considering that the adhesive composition is used in a positive electrode plate and must be able to withstand subsequent laser irradiation, the insulating filler may be an inorganic material that does not soften or melt at temperatures above 600°C, typically above 700°C, for example above 900°C, has heat resistance that can insulate the positive electrode and the negative electrode, and is electrochemically stable.

[0067] In some embodiments, the insulating filler may include one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder. Each insulating filler has a different hardness, with boehmite having a more moderate hardness. This not only improves the stability of the insulating adhesive layer, but also prevents the hardness from adversely affecting the battery separator.

[0068] In some embodiments, in order to further improve the dispersion effect of the insulating filler in the adhesive and at the same time avoid the influence on the separator due to the filler particle size being too large, the D V The Dv50 particle size is ≦1 μm. Insulating fillers within this particle size range can be completely embedded in insulating layers of normal thickness, thereby effectively controlling the friction of the insulating filler against the separator. The Dv50 above represents the volume average particle size, which is the particle size corresponding to the cumulative volume distribution rate of the material reaching 50%. The test method refers to standard GB / T 19077-2016, and can be measured using a laser particle size analyzer (e.g., Malvern Master Size 3000).

[0069] The dispersant used in the adhesive of the present application can be selected from common dispersants that are advantageous for dispersing insulating fillers. In some embodiments, the dispersant includes one or more of polyacrylate-based compounds, aliphatic alcohol polyether-based compounds, and polyether-modified siloxane-based compounds, such as Chemadd-6004 from Yueyang Kaimen Aqueous Auxiliaries Co., Ltd. and Elaecpure LW-10 from Tao Chemical. Solvent-free adhesives are more convenient for packaging and transportation, while solvent-containing adhesives are more convenient for use. Different solid content adhesives have different viscosities and coating possibilities. Curing conditions also vary, and those skilled in the art can select the solid content according to application requirements. In some embodiments, the solid content of the adhesive is optionally 20% to 40% to improve application and curing efficiency. The viscosity of the adhesive measured at 25°C and 12 rpm is 550 mPa·s.

[0070] In some embodiments, to save costs and improve the safety of the operating environment, the solvent of the adhesive optionally comprises water, i.e., a water-based adhesive is provided.

[0071] [Adhesive composition] A second aspect of the present application provides a pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive. Here, the pressure-sensitive adhesive comprises a first pressure-sensitive adhesive and a second pressure-sensitive adhesive. The first pressure-sensitive adhesive is a polymer and comprises structural units A, B, C, and D. The second pressure-sensitive adhesive is a polymer and comprises structural units A, C, and D. Here, the structural unit A is JPEG2026501212000035.jpg35130. The structural units B are each independently JPEG2026501212000036.jpg30130JPEG2026501212000037.jpg30130JPEG2026501212000038.jpg41130JPEG2026501212000039.jpg30130or JPEG2026501212000040.jpg30130, and optionally, the structural unit B is JPEG2026501212000041.jpg30130 or JPEG2026501212000042.jpg30130. The structural unit C of the first adhesive and the structural unit C of the second adhesive are each independently JPEG2026501212000043.jpg41130 or JPEG2026501212000044.jpg41130, and each m1 and each m2 is independently an integer of 1 to 20, for example, m1 is 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18, or 20, and m2 is 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18, or 20, and optionally, m1 is independently an integer of 2 to 12, and m2 is independently an integer of 8 to 12. The structural unit D of the first pressure-sensitive adhesive and the structural unit D of the second pressure-sensitive adhesive are each independently JPEG2026501212000045.jpg41130, and n1 are each independently any integer from 1 to 20, for example, n1 is 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18 or 20, optionally n1 are each independently any integer from 1 to 12, and further optionally n1 are each independently any integer from 1 to 6.

[0072] When this adhesive composition is used in a positive electrode plate to produce an insulating adhesive layer, the structural unit B in the first adhesive is provided via an acrylonitrile monomer. This monomer is a hard monomer and can reinforce the strength of the insulating adhesive layer. The structural unit C in the first adhesive and the second adhesive is provided by an acrylate monomer. The acrylate monomer is a soft monomer and can improve the flexibility of the insulating adhesive layer and reinforce the adhesive strength between the insulating adhesive layer and the current collector.

[0073] At the same time, the structural unit A in the first adhesive and the structural unit D in the second adhesive, and the structural unit D in the first adhesive and the structural unit A in the second adhesive, form a three-dimensional crosslinked network through hydrogen bonding interactions. The resulting insulating adhesive layer has excellent abrasion resistance, effectively isolating the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell, and effectively preventing short circuits between the tab and the positive electrode film layer. On the other hand, both the first and second adhesives in this adhesive composition are acrylic acid-based monomers. Because acrylic acid-based materials are resistant to high temperatures and decomposition, the resulting insulating adhesive layer prevents the current collector of the positive electrode plate from being directly cut by the laser and effectively resists metal particle scattering. Furthermore, when the insulating adhesive layer is cut by a laser, molten metal bead particles are less likely to be generated, effectively mitigating the problem of metal particle scattering causing separator damage when the current collector is directly cut by a laser. At the same time, the three-dimensional crosslinked network also further reinforces the resistance to laser cutting, and provides better protection for the separator.

[0074] In some embodiments of the present application, to further improve the overall performance of the insulating adhesive layer formed from the pressure-sensitive adhesive composition, the weight ratio of the first adhesive to the second adhesive is optionally 1:2.5 to 1:20, e.g., 1:17.5, 2:17.5, 4:17.5, 1:5, 2:12.5, 2:15, or 1:10, and is preferably 1:5 to 1:17.5. The amount of the second adhesive used is relatively greater than the amount of the first adhesive used, providing the insulating adhesive layer with relatively good adhesion and flexibility, while an appropriate amount of the first adhesive is used to improve the strength of the insulating adhesive layer, thereby better matching the strength of the insulating filler in the pressure-sensitive adhesive composition and the strength of the positive electrode current collector, thereby fully demonstrating adhesive strength. Furthermore, the weight ratio is used to adjust the crosslink network density of the insulating adhesive layer, providing sufficient network support for wear resistance and protection against the current collector.

[0075] The first and second PSA compositions of the present application may both be formed by polymerizing an acrylic acid monomer and an acrylic acid derivative monomer corresponding to the structural unit. In some embodiments of the present application, the first PSA is a copolymer, with different contents of each structural unit resulting in different PSA properties, allowing for adjustment of the properties of each PSA and for the two PSAs to work together to achieve a better synergistic effect. The first PSA may optionally satisfy one or more of the following conditions: 1) the molar content of structural unit A in the first PSA is 5% to 30%, 2) the molar content of structural unit B in the first PSA is 5% to 85%, optionally 5% to 55%, 3) the molar content of structural unit C in the first PSA is 5% to 85%, optionally 35% to 85%, and 4) the molar content of structural unit D in the first PSA is 5% to 15%. The hardness of the first adhesive can be adjusted by adjusting the content of structural unit B and structural unit C to meet the hardness requirements of insulating adhesive layers with different designs and processing methods. The content of structural unit A and structural unit D is relatively low in all structural units, and they are mainly used to form a crosslinked network with the second adhesive, while also well controlling the self-crosslinking of both in the first adhesive.

[0076] In some embodiments of the present application, the second adhesive is a copolymer. Optionally, the second adhesive satisfies one or more of the following conditions: 1) the molar content of structural unit A in the second adhesive is 5% to 10%, 2) the molar content of structural unit C in the second adhesive is 70% to 85%, and 3) the molar content of structural unit D in the second adhesive is 5% to 20%. The structural unit C accounts for a major proportion in the second adhesive, thereby providing the second adhesive with sufficient flexibility and adhesive strength, thereby improving the adhesive strength of the insulating adhesive layer formed from the adhesive composition to the insulating filler and the positive electrode current collector.

[0077] The adhesive targets of the first and second adhesives in the adhesive composition of the present application are an insulating filler and a substrate. Due to gravity, the insulating filler will experience sedimentation in the adhesive solution formed by the adhesive composition. When the sedimentation is particularly severe, it can affect the adhesive strength of the insulating adhesive layer on the substrate. In some embodiments of the present application, the weight-average molecular weight of the first adhesive is 500,000 to 1,500,000. The relatively high viscosity of the first adhesive with this weight-average molecular weight provides a relatively good suspending effect for the insulating filler, effectively preventing sedimentation of the insulating filler and improving the adhesive strength of the insulating adhesive layer.

[0078] The second adhesive has relatively good flexibility and flowability, but its suspending effect on insulating fillers is not as good as that of the first adhesive. However, the second adhesive also has the characteristics of a typical polymer, namely, its viscosity increases with increasing molecular weight. In some embodiments, the second adhesive is still used to provide sufficient flowability to the adhesive solution formed by the adhesive composition, facilitating application. Optionally, the difference in weight-average molecular weight between the first adhesive and the second adhesive is 0 to 1.5 million. This difference may be a difference when the weight-average molecular weight of the first adhesive is greater than that of the second adhesive, or a difference when the weight-average molecular weight of the first adhesive is smaller than that of the second adhesive.

[0079] In some embodiments, the adhesive further comprises an insulating filler and / or a dispersing agent. In the adhesive composition of the present application, the use of the insulating filler reduces the cost of the composition, and the dispersing agent promotes the dispersion effect of the insulating filler in the adhesive. In addition, the carboxyl group can form hydrogen bonds with the insulating filler to improve the adhesive strength of the resulting insulating adhesive layer.

[0080] The ratio of insulating filler, adhesive, and dispersant can be determined by reference to the composition of a typical adhesive composition. In some embodiments, the weight ratio of insulating filler, adhesive, and dispersant is (70-90):(10-25):0.4. The use of insulating filler can reduce costs. Furthermore, the dispersant can improve the dispersion effect of insulating filler in the adhesive, avoid subsequent crosslinking of the adhesive, and provide sufficient adhesive strength to provide relatively good adhesion.

[0081] The insulating filler may be an insulating filler commonly used in adhesives. Considering that the adhesive composition is used in a positive electrode plate and must be able to withstand subsequent laser irradiation, the insulating filler may be an inorganic material that does not soften or melt at temperatures above 600°C, typically above 700°C, for example above 900°C, has heat resistance that can insulate the positive electrode and the negative electrode, and is electrochemically stable.

[0082] In some embodiments, the insulating filler may include one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder. Each insulating filler has a different hardness, with boehmite having a more moderate hardness. This not only improves the stability of the insulating adhesive layer, but also prevents the hardness from adversely affecting the battery separator.

[0083] In some embodiments, in order to further improve the dispersion effect of the insulating filler in the adhesive and at the same time avoid the influence on the separator due to the filler particle size being too large, the D V 50 particle size ≦1 μm. Insulating fillers within this particle size range can be completely embedded in an insulating layer of normal thickness, thereby effectively controlling the friction of the insulating filler against the separator.

[0084] The dispersant used in the pressure-sensitive adhesive composition of the present application can be selected from common dispersants that are advantageous for dispersing insulating fillers. In some embodiments, the dispersant includes one or more of polyacrylate-based compounds, aliphatic alcohol polyether-based compounds, and polyether-modified siloxane-based compounds, such as Chemadd-6004 from Yueyang Kaimen Aqueous Auxiliary Agent Co., Ltd. and Elaecpure LW-10 from Taoist Chemical.

[0085] In some embodiments, the pressure-sensitive adhesive composition further comprises a solvent. Without a solvent, the pressure-sensitive adhesive composition is more convenient to package and transport, while including a solvent makes the pressure-sensitive adhesive composition more convenient to use. Different solid contents result in different viscosities of the pressure-sensitive adhesive composition, different application applicability, and different curing conditions. Therefore, those skilled in the art can select the solid content according to application requirements. In some embodiments, the solid content of the pressure-sensitive adhesive composition is optionally 20% to 40% to improve application and curing efficiency. In some embodiments, the solvent of the pressure-sensitive adhesive composition optionally comprises water to save costs and improve the safety of the operating environment. That is, a water-based pressure-sensitive adhesive is provided.

[0086] In some embodiments, the abrasion resistance, cohesion, hardness and adhesion of the adhesive composition also meet the adhesive requirements set forth above, and will not be further described herein.

[0087] The first and second adhesives used in the pressure-sensitive adhesive composition of the present application can be manufactured by referring to the manufacturing methods of the prior art or can adopt known materials. In order to facilitate those skilled in the art in carrying out the present application, the following manufacturing methods are provided for reference.

[0088] First adhesive: Dissolve surfactant in water at 10°C to 30°C, and mix monomer A CH2=CHCOOH, monomer B CH2=CHCN, and monomer C CH2=CHCOO(CH2). m1 CH3 and monomer D CH2=CHCOO(CH2) n1The OH and chain transfer agent (e.g., n-dodecyl mercaptan) were added sequentially and blended uniformly. Nitrogen gas was injected during this process to remove oxygen and protect the mixture. A pre-emulsion was formed, and the pre-emulsion was heated to 80-90°C. A surfactant (e.g., dialkyl sulfosuccinate ester salt M-30S) was dissolved in deionized water, added to the reactor, and stirred. Nitrogen gas was injected for oxygen removal and protection, and the temperature was raised to 80-90°C to obtain a reactive surfactant solution. A first initiator solution was prepared using ammonium persulfate in deionized water. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reactor. After the addition was complete, the mixture was kept warm to obtain an acrylic acid (ester) copolymer seed solution. A second initiator solution was prepared using ammonium persulfate in deionized water. The concentration of the second initiator solution was greater than that of the first initiator solution, and the second initiator solution was added dropwise to the acrylic acid (ester) copolymer seed solution. The dropwise addition continued for 100 to 150 minutes, and after completion of the dropwise addition, the temperature was maintained for 1 to 3 hours to obtain an acrylic acid (ester) copolymer solution. The temperature of the acrylic acid (ester) copolymer solution in the reaction vessel was lowered to 60 to 70°C and then allowed to naturally cool to room temperature. The pressure was reduced to remove gas, and the degree of vacuum in the reaction vessel was reduced to less than 0.09 MPa, which was maintained for 10 to 50 minutes. The air was then released to atmospheric pressure, and the mixture was filtered to obtain an aqueous adhesive emulsion. The pH was then adjusted to 7 to 8.

[0089] Second adhesive: Dissolve surfactant in water at 10°C to 30°C, and mix monomer A CH2=CHCOOH and monomer C CH2=CHCOO(CH2). m1 CH3, Monomer D CH2=CHCOO(CH2) n1The OH and chain transfer agent (e.g., n-dodecyl mercaptan) were added sequentially and blended uniformly. Nitrogen gas was injected during this process to remove oxygen and protect the mixture. A pre-emulsion was formed, and the pre-emulsion was heated to 80-90°C. A surfactant (e.g., dialkyl sulfosuccinate ester salt M-30S) was dissolved in deionized water, added to the reactor, and stirred. Nitrogen gas was injected for oxygen removal and protection, and the temperature was raised to 80-90°C to obtain a reactive surfactant solution. A first initiator solution was prepared in deionized water, and the pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reactor. After the addition was complete, the mixture was kept warm to obtain an acrylic acid (ester) copolymer seed solution. A second initiator solution was prepared in deionized water, and the concentration of the second initiator solution was greater than that of the first initiator solution. The second initiator solution was added dropwise to the acrylic acid (ester) copolymer seed solution. The dropwise addition continued for 100 to 150 minutes, and after completion of the dropwise addition, the temperature was maintained for 1 to 3 hours to obtain an acrylic acid (ester) copolymer solution. The temperature of the acrylic acid (ester) copolymer solution in the reaction vessel was lowered to 60 to 70°C and then allowed to naturally cool to room temperature. The pressure was reduced to remove gas, and the degree of vacuum in the reaction vessel was reduced to less than 0.09 MPa, which was maintained for 10 to 50 minutes. The air was then released to atmospheric pressure, and the mixture was filtered to obtain an aqueous adhesive emulsion. The pH was then adjusted to 7 to 8.

[0090] [Secondary battery] A secondary battery is also called a rechargeable battery or a storage battery, and is a battery that can be continuously used by activating the active material through a charging method after discharging the battery.

[0091] Generally, a secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. During charging and discharging of the battery, active ions (e.g., lithium ions) are absorbed and released back and forth between the positive electrode plate and the negative electrode plate. The separator, located between the positive electrode plate and the negative electrode plate, primarily prevents short-circuiting between the positive and negative electrodes and allows the active ions to pass through. The electrolyte primarily conducts the active ions between the positive electrode plate and the negative electrode plate.

[0092] The adhesive composition may be used in a position requiring an adhesive in a secondary battery, or may be used as a separator raw material. In some embodiments, the adhesive composition is used in a positive electrode plate.

[0093] [Positive electrode plate] As shown in FIG. 1, a positive electrode plate 10 generally includes a positive electrode current collector 11 and a positive electrode film layer 12 disposed on at least one side of the positive electrode current collector 11, and the positive electrode film layer 12 includes a positive electrode active material.

[0094] For example, the positive electrode current collector 11 has two surfaces that face each other in the thickness direction thereof, and the positive electrode film layer 12 is disposed on one or both of the two facing surfaces of the positive electrode current collector 11.

[0095] As shown in FIG. 1 , in addition to the positive electrode film layer 12 disposed on the positive electrode current collector 11, a bare foil region is also present around the periphery of the positive electrode film layer 12. In some embodiments of the present application, the positive electrode plate 10 further includes an insulating adhesive layer 13 disposed on the bare foil region of the positive electrode current collector 11. Here, the insulating adhesive layer 13 is formed by curing the adhesive composition provided by any of the above embodiments. The specific location of the insulating adhesive layer 13 on the bare foil region can refer to prior art, for example, avoidance of the root portion of the tab.

[0096] The insulating adhesive layer 13 in the positive electrode plate 10 is formed by curing the above-described adhesive composition of the present application. On the one hand, the structural unit A in the first adhesive and the structural unit D in the second adhesive, and the structural unit D in the first adhesive and the structural unit A in the second adhesive, form a three-dimensional crosslinked network through hydrogen bonding interactions. This provides the insulating adhesive layer with excellent abrasion resistance, effectively isolating the contact and friction between the base of the tab and the edge of the positive electrode plate caused by the tab bending when the battery core is inserted into the shell, and effectively preventing short circuits between the tab and the positive electrode film layer. On the other hand, both the first and second adhesives in this adhesive composition are acrylic acid-based monomers. Because acrylic acid-based materials are resistant to high temperatures and are resistant to decomposition, the insulating adhesive layer can prevent the positive electrode plate current collector from being directly cut by a laser and effectively resist the scattering of metal particles. Furthermore, when the insulating adhesive layer is cut by a laser, molten metal beads are unlikely to be generated, effectively alleviating the problem of scattering metal particles damaging the separator when the laser directly cuts the current collector. At the same time, the three-dimensional crosslinked network also further reinforces the resistance to laser cutting, providing better protection for the separator.

[0097] The carboxyl groups of the first and second adhesives can form hydrogen bonds with the insulating filler to improve the adhesive strength of the insulating adhesive layer. The structural unit B in the first adhesive is provided via an acrylonitrile monomer. This monomer is a hard monomer and can reinforce the strength of the insulating adhesive layer. The structural unit C in the first and second adhesives is provided by an acrylate monomer. The acrylate monomer is a soft monomer and can improve the flexibility of the insulating adhesive layer and reinforce the adhesive strength between the insulating adhesive layer and the current collector.

[0098] The thickness of the insulating adhesive layer 13 of the positive electrode plate 10 can be determined based on the typical thickness of an insulating adhesive layer, or can be set according to the design requirements of the battery. In some embodiments, the thickness of the insulating adhesive layer 13 is equal to or less than the thickness of the positive electrode film layer 12, and optionally, the thickness of the insulating adhesive layer 13 is 3 μm to 7 μm. This not only provides protection for the positive electrode current collector 11, but also prevents an increase in the volume of the battery core due to an excessively thick insulating adhesive layer 13.

[0099] The process for forming the insulating adhesive layer can refer to conventional techniques, such as coating. In some embodiments, the process for forming the insulating adhesive layer includes mixing the components of the pressure-sensitive adhesive composition to form an adhesive solution, coating the adhesive solution on the bare foil area of ​​the positive electrode current collector to obtain a preform having the adhesive solution, and heating the preform having the adhesive solution to obtain an insulating adhesive layer, optionally at a heating temperature of 90°C to 120°C, thereby accelerating the removal rate of the solvent therein.

[0100] In some embodiments, in order to improve the uniformity of mixing of the components in the PSA composition, the process of mixing the components of the PSA composition to form an adhesive solution includes: mixing a dispersant in the PSA composition with water to form a first dispersion, optionally with first stirring, a first stirring time of 5 to 30 minutes, and a stirring speed of 200 to 400 rpm; mixing the first dispersion with an insulating filler in the PSA composition to form a second dispersion, optionally with second stirring, a second stirring time of 30 to 120 minutes, and a stirring speed of 1200 to 1800 rpm; and mixing the second dispersion with a first PSA in the PSA composition to form a third dispersion, optionally with third stirring, a third stirring time of 15 to 60 minutes, and a stirring speed of 400 to 700 rpm. Mixing the third dispersion with the second adhesive in the adhesive composition to form an adhesive solution, optionally including fourth stirring, the fourth stirring time being 5 minutes to 30 minutes, and the stirring speed being 200 rpm to 400 rpm.

[0101] In the above process, there is no need to adjust the stirring time and speed according to the mixing targets, and the mixing effect of each component is improved by using stirring.

[0102] In some embodiments, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, aluminum foil may be used as the metal foil sheet. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0103] In some embodiments, the positive electrode active material may be a positive electrode active material for batteries known in the art. For example, when the secondary battery is a lithium-ion secondary battery, the positive electrode active material may include at least one material selected from the group consisting of a lithium-containing phosphate with an olivine structure, a lithium transition metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other conventional materials usable as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO), lithium nickel oxide (e.g., LiNiO), lithium manganese oxide (e.g., LiMnO, LiMnO), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05Examples of the lithium-containing phosphate having an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0104] When the secondary battery is a sodium ion secondary battery, for example, the positive electrode active material of the sodium ion secondary battery may include at least one material selected from the group consisting of a sodium transition metal oxide, a polyanion compound, and a Prussian blue compound. However, the present application is not limited to these materials, and other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries may also be used.

[0105] As an optional technical solution of the present application, the transition metal in the sodium transition metal oxide may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce. The sodium transition metal oxide may be, for example, Na x MO2, where M is one or more of Ti, V, Mn, Co, Ni, Fe, Cr and Cu; <x≦1である。

[0106] As an alternative technical solution of the present application, the polyanion type compound is a compound containing sodium ions, transition metal ions and tetrahedral (YO4) n- The compound may have an anionic unit. The transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. Y may be at least one of P, S, and Si. n is (YO4) n- represents the valence of

[0107] Polyanionic compounds can also be used with sodium ions, transition metal ions, and tetrahedral (YO4) n-The compound may have an anionic unit and a halogen anion. The transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. Y may be at least one of P, S, and Si. n is (YO4) n- The halogen may be at least one of F, Cl, and Br.

[0108] Polyanionic compounds also contain sodium ions, tetrahedral (YO4) n- Anionic unit, polyhedral unit (ZO y ) m+ and optionally a halogen anion. Y may be at least one of P, S, and Si, and n is (YO4) n- Z represents a transition metal, and may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. m represents a valence of (ZO y ) m+ The halogen may be at least one of F, Cl, and Br.

[0109] Polyanionic compounds include, for example, NaFePO4, Na3V2(PO4) (sodium vanadium triphosphate, abbreviated as NVP), Na4Fe3(PO4)2(P2O7), NaM'PO4F (where M' is one or more of V, Fe, Mn, and Ni), and Na3(VO y )2(PO4)2F 3-2y At least one of (0≦y≦1).

[0110] Prussian blue compounds contain sodium ions, transition metal ions, and cyanide ions (CN - The transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. The Prussian blue compound may be, for example, Na a Me b Me´ c(CN)6, where Me and Me' are each independently at least one of Ni, Cu, Fe, Mn, Co, and Zn; <a≦2、0<b<1、0<c<1である。

[0111] In some embodiments, the positive electrode membrane layer optionally further comprises an adhesive, which may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0112] In some embodiments, the positive electrode film layer optionally further comprises a conductive agent, for example, the conductive agent may comprise at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0113] In some embodiments, a positive electrode plate can be manufactured as follows: The components for manufacturing the positive electrode plate, such as a positive electrode active material, a conductive agent, an adhesive, and other optional components, are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry. The positive electrode slurry is coated on a positive electrode current collector, and after processes such as drying and cold pressing, a positive electrode plate is obtained.

[0114] [Negative electrode plate] The negative electrode plate includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material.

[0115] For example, the negative electrode current collector has two surfaces that face each other in the thickness direction, and the negative electrode film layer is disposed on one or both of the two facing surfaces of the negative electrode current collector.

[0116] In some embodiments, the negative electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be copper foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer base material (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0117] In some embodiments, the negative electrode active material may be any negative electrode active material known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicone-based material, a tin-based material, and lithium titanate. The silicone-based material may be selected from at least one of a silicone element, a silicone oxide, a silicone carbon composite, a silicone nitrogen composite, and a silicone alloy. The tin-based material may be selected from at least one of a tin element, a tin oxide, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials usable as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination.

[0118] In some embodiments, the negative electrode membrane layer optionally further comprises an adhesive, for example, the adhesive may be selected from at least one of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0119] In some embodiments, the negative electrode film layer optionally further comprises a conductive agent, for example, the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0120] In some embodiments, the negative electrode membrane layer optionally further comprises other additives, such as a thickener (eg, carboxymethylcellulose sodium (CMC-Na)).

[0121] In some embodiments, a negative electrode plate can be manufactured as follows: The components for manufacturing the negative electrode plate, such as the negative electrode active material, conductive agent, adhesive, and other optional components, are dispersed in a solvent (e.g., deionized water) to form a negative electrode slurry. The negative electrode slurry is coated on a negative electrode current collector, and after processes such as drying and cold pressing, a negative electrode plate is obtained.

[0122] [Electrolyte] The electrolyte serves to conduct ions between the positive and negative electrodes. The present application does not specifically limit the type of electrolyte, and it can be selected according to needs. For example, the electrolyte may be liquid, gel, or all solid.

[0123] In some embodiments, the electrolyte is liquid and includes an electrolyte salt and a solvent.

[0124] In some embodiments, electrolyte salts used in lithium-ion secondary batteries may include one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, or lithium tetrafluoro(oxalato)phosphate. Electrolyte salts used in sodium-ion secondary batteries may include one or more of sodium hexafluorophosphate (NaPF), sodium tetrafluoroborate (NaBF), sodium hexafluoroarsenate (NaAsF), sodium trifluoroacetate (CFCOONa), sodium trifluoromethanesulfonate (CFNaOS, NaOTf), or sodium tetraphenylborate (NaBPh).

[0125] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone.

[0126] In some embodiments, the electrolyte solution may further optionally contain additives. For example, the additives may include a negative electrode film-forming additive, a positive electrode film-forming additive, and / or an additive that can improve some battery performance, such as an additive that improves the battery's overcharge performance or improves the battery's high-temperature or low-temperature performance.

[0127] [Separator] In some embodiments, the secondary battery further includes a separator. The present application does not particularly limit the type of separator, and any known porous separator with good chemical stability and mechanical stability may be selected.

[0128] In some embodiments, the separator may be made of at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without any particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without any particular limitation.

[0129] In some embodiments, the positive and negative electrodes and the separator can be fabricated into an electrode assembly by a winding or lamination process.

[0130] In some embodiments, the secondary battery includes secondary battery cells, or includes battery modules and battery packs.

[0131] In some embodiments, the secondary battery may include an exterior body, which may be used to package the electrode assembly and electrolyte.

[0132] In some embodiments, the exterior of the secondary battery may be a hard case, such as a hard plastic case, an aluminum case, a steel case, etc. The exterior of the secondary battery may be a pouch, such as a bag-shaped pouch. The pouch may be made of plastic, such as polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0133] The present application does not particularly limit the shape of the secondary battery cell, which may be cylindrical, rectangular, or any other shape. For example, Figure 2 shows an example of a secondary battery cell 5 with a rectangular structure.

[0134] Referring to FIG. 3 , in some embodiments, the exterior body may include a case 51 and a cover plate 53. Here, the case 51 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate together form a surrounding receiving cavity. The case 51 has an opening communicating with the receiving cavity, and the cover plate 53 can cover the opening to seal the receiving cavity. The positive electrode plate, the negative electrode plate, and the separator may be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is packaged in the receiving cavity. An electrolyte is impregnated into the electrode assembly 52. ​​The number of electrode assemblies 52 included in the secondary battery cell 5 may be one or more, and those skilled in the art can select the number according to actual needs.

[0135] In some embodiments, the secondary battery cells may be assembled into a battery module, which may include one or more secondary battery cells, the specific number of which can be selected by those skilled in the art depending on the application and capacity of the battery module.

[0136] Fig. 4 shows an example of a battery module 4. Referring to Fig. 4, in the battery module 4, a plurality of secondary battery cells 5 may be arranged in order along the longitudinal direction of the battery module 4. Of course, they may be arranged in any other manner. Furthermore, the plurality of secondary battery cells 5 may be fixed by fasteners.

[0137] Optionally, the battery module 4 may further include a housing having an accommodating space in which the plurality of secondary battery cells 5 are accommodated.

[0138] In some embodiments, the battery modules may be further assembled into a battery pack, which may include one or more battery modules, the specific number of which can be selected by those skilled in the art depending on the application and capacity of the battery pack.

[0139] 5 and 6 show an example of a battery pack 1. Referring to FIGS. 5 and 6, the battery pack 1 may include a battery box and a plurality of battery modules 4 installed in the battery box. The battery box may include an upper housing 2 and a lower housing 3, and the upper housing 2 may cover the lower housing 3 to form an enclosed space for accommodating the battery modules 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.

[0140] The present application also provides a power consuming device. The power consuming device includes a secondary battery according to the present application. The secondary battery may be used as a power source for the power consuming device or as an energy storage unit for the power consuming device. The power consuming device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, energy storage systems, etc.

[0141] The power consumption device can be selected as a secondary battery cell, a battery module, or a battery pack depending on its usage needs.

[0142] 7 shows an example of a power consuming device, such as a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the demand for high power output and high energy density of the secondary battery of the power consuming device, a battery pack or battery module can be employed.

[0143] [Example] The following describes examples of the present application. The examples described below are illustrative and are intended to interpret the present application, but should not be understood as limitations on the present application. If no specific techniques or conditions are described in the examples, they are carried out according to the techniques, conditions, or product specifications described in documents within the field. If no manufacturer is specified for the reagents or equipment used, they are all ordinary products that are commercially available.

[0144] The first adhesive (the structural unit B is The manufacturing process for the image (JPEG2026501212000046.jpg30130) is as follows:

[0145] At an operating temperature of 20°C, 5.4 g of the reactive surfactant double bond group-containing dialkyl sulfosuccinate salt M-30S was dissolved in 62 g of deionized water, and the monomers A, CH2=CHCOOH, B, CH2=CHCN, and C, CH2=CHCOO(CH2), were added. m1 CH3 and monomer D CH2=CHCOO(CH2) n1OH and 0.058 g of the chain transfer agent n-dodecyl mercaptan were added sequentially, the rotation speed was increased to 350 rpm, and the mixture was blended uniformly for 25 minutes. Nitrogen gas was injected for protection during this time, and the flow rate was increased to 110 mL / min to form a pre-emulsion. The pre-emulsion was heated to 85°C at a heating rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a pre-emulsion. 3.8 g of the reactive surfactant double-bond group-containing dialkyl sulfosuccinate ester salt M-30S was dissolved in 61.3 g of deionized water. The mixture was added to a reactor, the rotation speed was increased to 300 rpm, nitrogen gas was used for oxygen removal protection, and the flow rate was increased to 100 mL / min. The mixture was heated to 88°C at a heating rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a reactive surfactant solution. A 3.5 g solution of ammonium persulfate was prepared in deionized water as a first initiator solution. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reaction vessel. After 160 min of addition, the mixture was maintained at room temperature for 0.5 h to obtain a seed solution. A 1.0 g solution of ammonium persulfate was prepared in deionized water as a second initiator solution, and the second initiator solution was added dropwise to the seed solution. The addition continued for 120 min, and after 2 h of addition, the mixture was maintained at room temperature to obtain an acrylic acid (ester) copolymer solution. The temperature of the acrylic acid (ester) copolymer in the reaction vessel was reduced to 65°C at a rate of 2°C / min, maintained for 30 min, and then allowed to cool naturally to room temperature. The pressure was reduced to remove gas, and the vacuum in the reaction vessel was reduced to less than 0.09 MPa and maintained for 30 min. The air was then released to atmospheric pressure and filtered through a 300-mesh filter cloth to obtain a second PSA emulsion with a solids content of 50%. Thereafter, the pH value was adjusted to 7 to 8. The solid content of this first adhesive was 15%.

[0146] The composition of the first pressure-sensitive adhesive was adjusted by adjusting the composition or amount of each monomer. The compositions of the obtained first pressure-sensitive adhesives 1 to 21 are shown in Table 1-1.

[0147] The first adhesive 22 (the structural unit B is The manufacturing process for the JPEG2026501212000047.jpg41130 is as follows:

[0148] At an operating temperature of 20°C, 5.4 g of the reactive surfactant double bond group-containing dialkyl sulfosuccinate salt M-30S was dissolved in 62 g of deionized water. Monomer A: CH₂=CHCOOH, Monomer B: Styrene, Monomer C: CH₂=CHCOO(CH₂). m1 CH3 and monomer D CH2=CHCOO(CH2) n1 OH and 0.058 g of the chain transfer agent n-dodecyl mercaptan were added sequentially, the rotation speed was increased to 350 rpm, and the mixture was blended uniformly for 25 minutes. Nitrogen gas was injected for protection during this time, and the flow rate was increased to 110 mL / min to form a pre-emulsion. The pre-emulsion was heated to 85°C at a rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a pre-emulsion. 3.8 g of the reactive surfactant double-bond group-containing dialkyl sulfosuccinate ester salt M-30S was dissolved in 61.3 g of deionized water. The mixture was added to a reactor, the rotation speed was increased to 300 rpm, and oxygen removal protection was performed with nitrogen gas. The flow rate was increased to 100 mL / min, the temperature was increased to 88°C at a rate of 2°C / min, and maintained at that temperature for 30 minutes to obtain a reactive surfactant solution. A 3.5 g solution of ammonium persulfate was prepared in deionized water as a first initiator solution. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reaction vessel. After the dropwise addition was completed for 160 min, the mixture was maintained at room temperature for 0.5 h to obtain a seed solution. A 1.0 g solution of ammonium persulfate was prepared in deionized water as a second initiator solution. The second initiator solution was added dropwise to the seed solution and continued to be added dropwise for 120 min. After the dropwise addition was completed, the mixture was maintained at room temperature for 2 h to obtain an acrylic acid (ester) copolymer solution. The acrylic acid (ester) copolymer in the reaction vessel was cooled to 65°C at a rate of 2°C / min, maintained at room temperature for 30 min, and then allowed to cool naturally to room temperature. The pressure was reduced to remove gas, and the vacuum in the reaction vessel was reduced to less than 0.09 MPa and maintained for 30 min. The air was then released to atmospheric pressure and filtered through a 300-mesh filter cloth to obtain a second PSA emulsion with a solids content of 50%. Thereafter, the pH value was adjusted to 7 to 8. The solid content of this first adhesive was 15%.

[0149] The first adhesive 23 (the structural unit B is The manufacturing process for the JPEG2026501212000048.jpg30130 is as follows:

[0150] At an operating temperature of 20°C, 5.4 g of the reactive surfactant double bond group-containing dialkyl sulfosuccinate salt M-30S was dissolved in 62 g of deionized water. Monomer A: CH₂=CHCOOH, Monomer B: methyl methacrylate, Monomer C: CH₂=CHCOO(CH₂). m1 CH3 and monomer D CH2=CHCOO(CH2) n1OH and 0.058 g of the chain transfer agent n-dodecyl mercaptan were added sequentially, the rotation speed was increased to 350 rpm, and the mixture was blended uniformly for 25 minutes. Nitrogen gas was injected for protection during this time, and the flow rate was increased to 110 mL / min to form a pre-emulsion. The pre-emulsion was heated to 85°C at a heating rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a pre-emulsion. 3.8 g of the reactive surfactant double bond group-containing dialkyl sulfosuccinate ester salt M-30S was dissolved in 61.3 g of deionized water. The mixture was added to a reactor, the rotation speed was increased to 300 rpm, and nitrogen gas was used for oxygen removal protection. The flow rate was increased to 100 mL / min, the temperature was increased to 88°C at a heating rate of 2°C / min, and maintained at that temperature for 30 minutes to obtain a reactive surfactant solution. A first initiator solution was prepared by dissolving 3.5 g of ammonium persulfate in deionized water. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reaction vessel. After the dropwise addition was completed for 160 min, the mixture was kept at room temperature for 0.5 h to obtain a seed solution. A 1.0 g ammonium persulfate initiator solution was prepared in deionized water as a second initiator solution. The second initiator solution was added dropwise to the seed solution and continued to be added dropwise for 120 min. After the dropwise addition was completed, the mixture was kept at room temperature for 2 h to obtain an acrylic acid (ester) copolymer solution. The acrylic acid (ester) copolymer in the reaction vessel was cooled to 65°C at a rate of 2°C / min, kept at room temperature for 30 min, and then allowed to cool naturally to room temperature. The pressure was reduced to remove gas, and the vacuum in the reaction vessel was reduced to less than 0.09 MPa and maintained for 30 min. The air was then released to atmospheric pressure and filtered through a 300-mesh filter cloth to obtain a second adhesive emulsion with a solids content of 50%. The pH was then adjusted to 7-8. The solids content of this first adhesive is 15%.

[0151] First adhesive 24 (structural unit C is lauryl methacrylate CH3CH2=CHCOO(CH2) 12 The manufacturing process for CH3 is as follows:

[0152] At an operating temperature of 20°C, 5.4 g of reactive surfactant double bond group-containing dialkyl sulfosuccinate salt M-30S was dissolved in 62 g of deionized water. Monomer A: CH₂=CHCOOH, Monomer B: CH₂=CHCN, Monomer C: CH₃CH₂=CHCOO(CH₂). 12 CH3 and monomer D CH2=CHCOO(CH2) n1 OH and 0.058 g of the chain transfer agent n-dodecyl mercaptan were added sequentially, the rotation speed was increased to 350 rpm, and the mixture was blended uniformly for 25 minutes. Nitrogen gas was injected for protection during this time, and the flow rate was increased to 110 mL / min to form a pre-emulsion. The pre-emulsion was heated to 85°C at a heating rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a pre-emulsion. 3.8 g of the reactive surfactant double bond group-containing dialkyl sulfosuccinate ester salt M-30S was dissolved in 61.3 g of deionized water and added to the reactor. The rotation speed was increased to 300 rpm, and nitrogen gas was used for oxygen removal protection. The flow rate was increased to 100 mL / min, the temperature was increased to 88°C at a heating rate of 2°C / min, and maintained at that temperature for 30 minutes to obtain a reactive surfactant solution. A first initiator solution was prepared by dissolving 3.5 g of ammonium persulfate in deionized water. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reaction vessel. After the dropwise addition was completed for 160 min, the mixture was kept at room temperature for 0.5 h to obtain a seed solution. A 1.0 g ammonium persulfate initiator solution was prepared in deionized water as a second initiator solution. The second initiator solution was added dropwise to the seed solution and continued to be added dropwise for 120 min. After the dropwise addition was completed, the mixture was kept at room temperature for 2 h to obtain an acrylic acid (ester) copolymer solution. The acrylic acid (ester) copolymer in the reaction vessel was cooled to 65°C at a rate of 2°C / min, kept at room temperature for 30 min, and then allowed to cool naturally to room temperature. The pressure was reduced to remove gas, and the vacuum in the reaction vessel was reduced to less than 0.09 MPa and maintained for 30 min. The air was then released to atmospheric pressure and filtered through a 300-mesh filter cloth to obtain a second adhesive emulsion with a solids content of 50%. The pH was then adjusted to 7-8. The solids content of this first adhesive is 15%.

[0153] [Table 1-1]

[0154] The molecular weights in Table 1-1 are weight average molecular weights rounded to the nearest ten thousand, and the test method can be measured using ultra-high efficiency polymer chromatography according to GB / T 21863-2008.

[0155] The manufacturing process of the second adhesive is as follows.

[0156] At an operating temperature of 20°C, 4.2 g (4.2%) of the reactive surfactant double bond group-containing dialkyl sulfosuccinate salt M-30S was dissolved in 58 g (116%) of deionized water. Monomer A: CH₂=CHCOOH, Monomer C: CH₂=CHCOO(CH₂). m1 CH3, Monomer D CH2=CHCOO(CH2) n1OH and 0.048 g (0.096%) of the chain transfer agent n-dodecyl mercaptan were added sequentially, the rotation speed was increased to 300 rpm, and the mixture was blended uniformly for 30 minutes. Nitrogen gas was injected during this time to protect against oxygen scavenging, and the flow rate was increased to 100 mL / min to form a pre-emulsion. The pre-emulsion was heated to 85°C at a heating rate of 2°C / min and maintained at that temperature for 30 minutes to obtain a pre-emulsion. 2.8 g (2.8%) of the reactive surfactant double-bond group-containing dialkyl sulfosuccinate ester salt M-30S was dissolved in 51.3 g (102.6%) of deionized water. The mixture was added to a reactor, the rotation speed was increased to 300 rpm, and nitrogen gas was used for oxygen scavenging. The flow rate was increased to 100 mL / min, the temperature was increased to 86°C at a heating rate of 2°C / min, and the temperature was maintained for 30 minutes to obtain a reactive surfactant solution. A 3 g (0.15 wt%) ammonium persulfate solution was prepared in deionized water as a first initiator solution. The pre-emulsion and the first initiator solution were simultaneously and continuously added dropwise to the reactive surfactant solution in the reaction vessel. After 150 min of dropwise addition, the mixture was maintained at room temperature for 0.5 h to obtain an acrylic acid (ester) copolymer seed solution. A 1.0 g (0.1 wt%) ammonium persulfate initiator solution was prepared in deionized water as a second initiator solution. The second initiator solution was added dropwise to the acrylic acid (ester) copolymer seed solution and continued to be added dropwise for 120 min. After 2 h of dropwise addition, the mixture was maintained at room temperature to obtain an acrylic acid (ester) copolymer solution. The acrylic acid (ester) copolymer in the reaction vessel was cooled to 65°C at a rate of 2°C / min, maintained at room temperature for 30 min, and then allowed to cool naturally to room temperature. The pressure was reduced to remove gas, and the vacuum in the reaction vessel was reduced to less than 0.09 MPa and maintained for 30 min. The air was then released to atmospheric pressure and filtered through a 300-mesh filter cloth to obtain a second adhesive emulsion with a solid content of 50%, after which the pH value was adjusted to 7-8.

[0157] The composition of the second adhesive was adjusted by adjusting the composition and amount of each monomer. The compositions of the obtained second adhesives 1 to 12 are shown in Table 1-2.

[0158] [Table 1-2]

[0159] The molecular weights in Table 1-2 are weight average molecular weights rounded to the nearest ten thousand, and the test method can be measured using ultra-high efficiency polymer chromatography according to the GB / T 21863-2008 standard.

[0160] Example 1 The dispersant was added to deionized water and stirred at 300 rpm for 15 minutes to obtain a first dispersion. The insulating filler was added to the first dispersion and stirred at 1500 rpm for 75 minutes to obtain a second dispersion. The first adhesive emulsion was added to the second dispersion and stirred at 1500 rpm for 60 minutes to obtain a third dispersion. The second adhesive emulsion was added to the third dispersion and stirred at 500 rpm for 60 minutes to obtain an adhesive solution. The specific materials and amounts used for the dispersant, insulating filler, first adhesive, and second adhesive are all listed in Table 2.

[0161] Examples 2 to 47 The corresponding adhesive solutions were prepared using the same process as in Example 1. The specific materials and amounts used as the dispersant, insulating filler, first adhesive (dry material), and second adhesive (dry material) for each example are all listed in Table 2.

[0162] Comparative Example 1 The dispersant was added to deionized water and the mixture was stirred at 300 rpm for 15 minutes to obtain a first dispersion. The insulating filler was added to the first dispersion, and the mixture was stirred at 1500 rpm for 75 minutes to disperse, thereby obtaining a second dispersion. The first adhesive emulsion was added to the second dispersion and stirred at 1500 rpm for 60 minutes to obtain an adhesive solution. The specific materials and amounts used as the dispersant, insulating filler, and first adhesive are all listed in Table 2.

[0163] Comparative Example 2 The dispersant was added to deionized water and the mixture was stirred at 300 rpm for 15 minutes to obtain a first dispersion. The insulating filler was added to the first dispersion, and the mixture was stirred at 1500 rpm for 75 minutes to disperse, thereby obtaining a second dispersion. The second pressure-sensitive adhesive emulsion was added to the second dispersion liquid, and the mixture was stirred at 1500 rpm for 60 minutes to disperse, thereby obtaining an adhesive solution.

[0164] The specific substances and amounts used as the dispersant, insulating filler, and second adhesive are shown in Table 2.

[0165] The dispersant used in each of the examples and comparative examples was Chemadd-6004 from Yueyang Kaimen Aqueous Dispersant Co., Ltd., with a mass content of 0.4 parts.

[0166] [Table 2] JPEG2026501212000052.jpg245151JPEG2026501212000053.jpg24555

[0167] Viscosity test: The rotational viscosity of the adhesive solution was tested at 25° C. and 12 rpm. The results are shown in Table 3.

[0168] Abrasion resistance test: Using a 5 μm scraper, each of the above adhesive solutions was squeegeeed onto a 13 μm aluminum foil, and then transferred to an oven at 100° C. to dry, producing an insulating adhesive layer to be tested.

[0169] RCA paper tape abrasion resistance tester (Standard Precision Instruments (Guangzhou) Co., Ltd. BGD 530). Test principle: A motor drives a paper tape to pass over an area of ​​the test sample surface at a constant speed, applying a constant pressure to abrade the test surface. Test method: A 5μm thick insulating adhesive layer to be tested and a 55g weight were run 300mm (2 laps) on a flat surface. The number of non-leakage points in the test area (a total of 10 points tested) is shown in Table 3, along with the area of ​​the leakage points. Based on this, the ratio of the area of ​​the non-leakage points to the total area of ​​the test area was calculated.

[0170] Evaluation standard: Under the same pressure, the longer the paper tape runs on the unpolished aluminum foil, the better the abrasion resistance. Or, when multiple non-leakage foil points are tested with the same running length, the more points there are, the better the abrasion resistance.

[0171] Cohesion test: The adhesive was prepared as a slurry and then coated onto the carbon coating layer of a carbon-coated copper foil. After drying, a sample sheet was obtained. One side of the sample sheet was the copper foil surface, and the other side was the adhesive layer formed by the adhesive. The sample sheet was then cut into strips measuring 2 cm wide and 6 cm long. The copper foil side of this strip was attached to the surface of a hard substrate (steel plate) using 3M-55230H double-sided tape (careful not to create any air bubbles during the attachment process). 3M-55230H double-sided tape was then attached to the adhesive layer side of the fixed strip, and copper foil of the same size as the double-sided tape was then covered onto the surface of the double-sided tape (careful not to create any air bubbles during the attachment process). The double-sided tape used was the same size, and test samples were obtained.

[0172] The copper foil and double-sided tape at the first end of the test sample were manually peeled off in a 180° direction, leaving the tape 1 cm behind the opposite end of the first end (i.e., the second end). The first end (hard substrate, carbon-coated copper foil, adhesive layer) was fixed using a jig at one end of the tensile tester, and the second end was fixed using a jig at the other end of the tensile tester.

[0173] The test was performed using a tensile tester with a tensile speed of 50 mm / min and a test length of 100 mm. The peel force data obtained from the test represents the cohesive strength of the coating material. The results are shown in Table 3.

[0174] Hardness test: A Shore A hardness tester was used to test the hardness of the insulating adhesive layer surface. The results are shown in Table 3.

[0175] Adhesion Test: Each of the adhesive solutions was applied to a 13 μm aluminum foil using a 5 μm scraper, and then transferred to an oven at 100° C. to dry, producing an insulating adhesive layer to be tested.

[0176] A blade was used to cut the above-mentioned insulating adhesive layer-attached specimens to a width of 20 mm and a length of 100–160 mm. The dedicated double-sided tape, NITTO NO5000NS, was applied to a steel plate, and a paper tape, 20 mm wide and 90–150 mm long, equal in width to the specimen but 80–200 mm longer than the specimen, was attached to the double-sided tape. Wrinkle-removing tape was then placed on top of the paper tape, and the cut specimens were attached to the wrinkle-removing tape. With the insulating adhesive layer facing down, the specimen surface was rolled three times in the same direction with a 3 kg press roller to obtain test specimens. The test specimen was fixed on the testing machine, and the end of the steel plate not attached to the electrode plate was fixed with the lower jig. The paper tape was folded upward and fixed with the upper jig, aligning the specimen's axis with the direction of force application. The testing machine was loaded at a peel rate of 10 mm / min until the specimen broke, at which point the test was stopped. The maximum load force was F (unit: N), the sample width L was 20 mm, and the peel strength f1 (unit: N / m) was calculated according to f1 = F / L. The peel strength is the adhesive strength. The results are shown in Table 3.

[0177] Heat resistance test: The test coating samples were subjected to thermogravimetric analysis using TG-DSC technique. The thermal decomposition temperatures are shown in Table 3.

[0178] [Table 3] JPEG2026501212000055.jpg161169

[0179] As can be seen from a comparison between each example and comparative example, the abrasion resistance of the insulating adhesive layer formed using the adhesive composition of the present application was clearly superior to the abrasion resistance when using either First Adhesive 1 or Second Adhesive 1 alone. First Adhesive 1 had too high a viscosity, which was disadvantageous for application when used alone, and the adhesive strength was too low. Second Adhesive 1 had too low a viscosity, which affected application performance and also affected the film-forming effect.

[0180] As can be seen from a comparison between Examples 2, 4, and 5, and a comparison between Example 1 and Examples 6 to 9, when the content of structural unit B in the first pressure-sensitive adhesive increases and the content of structural unit C decreases, i.e., when the content of the hard monomer structural unit in the first pressure-sensitive adhesive increases, the adhesive strength of the corresponding pressure-sensitive adhesive composition decreases.

[0181] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and equivalents may be substituted for elements therein without departing from the scope of the present application. In particular, the respective technical features mentioned in each embodiment may be combined in any manner unless there is a structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims. [Explanation of symbols]

[0182] 10 positive electrode plate, 11 positive electrode current collector, 12 positive electrode film layer, 13 insulating adhesive layer, 1 battery pack, 2 upper housing, 3 lower housing, 4 battery module, 5 rechargeable battery cell, 51 case, 52 electrode assembly, 53 cover plate.

Claims

1. An adhesive substance containing a pressure-sensitive adhesive, the adhesive substance containing a structural unit A, a structural unit B, a structural unit C, and a structural unit D, wherein at least a portion of the structural unit A is crosslinked with at least a portion of the structural unit D; Here, the structural unit A is and Here, the structural units B each independently represent or and optionally, the structural unit B is or and The structural units C each independently represent or is one of the following: each m1 and each m2 is independently any integer from 1 to 20, optionally each m1 is independently any integer from 2 to 12, and each m2 is independently any integer from 8 to 12; The structural units D each independently represent One or more of the following: n1 is independently any integer from 1 to 20, and optionally n1 is independently any integer from 1 to 12, and further optionally n1 is independently any integer from 1 to 6.

2. at least a portion of the structural units A, at least a portion of the structural units B, at least a portion of the structural units C, and at least a portion of the structural units D are connected in a chain to form a first chain structure; at least a portion of the structural units A, at least a portion of the structural units C, and at least a portion of the structural units D are connected in a chain to form a second chain structure; At least a portion of the structural units A in the first chain structure are crosslinked with at least a portion of the structural units D in the second chain structure; The adhesive substance according to claim 1 , wherein structural unit D in at least a portion of the first chain structure is cross-linked with structural unit A in at least a portion of the second chain structure.

3. The adhesive substance is 1) The abrasion resistance of the insulating adhesive layer formed by the adhesive material and having a thickness of 3 μm to 7 μm is tested by using an RCA paper tape abrasion resistance tester, and a 55 g weight is used to run the test piece 300 mm twice on a flat surface to form an experimental area, and n test points are taken in the experimental area, and the pitch of the test points is 2 cm or more, and the proportion of non-leakage points in the experimental area is 30% or more, where 5≦n≦100, or the area of ​​the non-leakage points in the experimental area is 60% or more of the total area of ​​the experimental area; 2) the cohesive strength of the insulating adhesive layer formed by the adhesive material is 620 N / m to 750 N / m, and optionally 660 N / m to 725 N / m; 3) The shore hardness of the insulating adhesive layer formed by the adhesive material is 45 HA to 80 HA, and optionally 50 HA to 65 HA; 4) The adhesive material according to claim 1 or 2, wherein the adhesive strength of the insulating adhesive layer formed by the adhesive material is 30 N / m to 90 N / m, and optionally 40 N / m to 80 N / m.

4. The adhesive substance according to any one of claims 1 to 3, wherein in the adhesive, the molar ratio of the structural unit D to the structural unit A is 0.5:1 to 5:1, optionally 0.5:1 to 3:1, and further optionally 1:1 to 3:1; optionally, the molar content of the structural unit A is 4% to 50%, optionally 4% to 10%; and optionally, the molar content of the structural unit D is 1% to 50%, optionally 5% to 30%, and further optionally 5% to 15%.

5. The adhesive substance according to any one of claims 1 to 4, wherein in the adhesive, the molar ratio of the structural unit C to the structural unit B is 1:1 to 300:1, optionally 5:1 to 50:1, optionally the molar content of the structural unit B is 0.2% to 20%, optionally 1% to 5%, and optionally the molar content of the structural unit C is 1% to 90%, optionally 55% to 90%, further optionally 75% to 80%.

6. The adhesive material according to any one of claims 1 to 5, further comprising an insulating filler and / or a dispersant, and optionally, the weight ratio of the insulating filler, the adhesive, and the dispersant is (70-90):(10-25):0.

4.

7. The insulating filler may include one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder, and optionally, the volume average particle size of the insulating filler may be D Ｖ The adhesive substance according to claim 6, wherein the particle size is 50≦1 μm.

8. The adhesive further comprises a solvent, and optionally the solid content of the adhesive is 20% to 40%; Optionally, the solvent of the adhesive material comprises water; The adhesive substance according to any one of claims 1 to 7, wherein the viscosity of the adhesive substance measured at 25°C and 12 rpm is 350 mPa·s to 900 mPa·s.

9. A pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive, the pressure-sensitive adhesive comprising a first pressure-sensitive adhesive and a second pressure-sensitive adhesive, the first PSA is a polymer and includes a structural unit A, a structural unit B, a structural unit C, and a structural unit D; the second PSA is a polymer and includes a structural unit A, a structural unit C, and a structural unit D; Here, the structural unit A is and The structural units B each independently represent or and optionally, the structural unit B is or and The structural unit C of the first pressure-sensitive adhesive and the structural unit C of the second pressure-sensitive adhesive are each independently or and each m1 and each m2 is independently any integer from 1 to 20, optionally each m1 is independently any integer from 2 to 12, and each m2 is independently any integer from 8 to 12; The structural unit D of the first pressure-sensitive adhesive and the structural unit D of the second pressure-sensitive adhesive are each independently and n1's each independently represent any integer from 1 to 20, optionally n1's each independently represent any integer from 1 to 12, and further optionally n1's each independently represent any integer from 1 to 6.

10. The pressure-sensitive adhesive composition according to claim 9, wherein the weight ratio of the first pressure-sensitive adhesive to the second pressure-sensitive adhesive is 1:2.5 to 1:20, and optionally 1:5 to 1:17.

5.

11. The first adhesive is 1) the molar content of the structural unit A in the first PSA is 5% to 30%; 2) the molar content of the structural unit B in the first PSA is 5% to 85%; 3) the molar content of the structural unit C in the first PSA is 5% to 85%; 4) the molar content of the structural unit D in the first PSA is 5% to 15%; The pressure-sensitive adhesive composition according to claim 9 or 10, which satisfies any one or more of the following conditions:

12. The second adhesive is 1) the molar content of the structural unit A in the second PSA is 5% to 10%; 2) the molar content of the structural unit C in the second PSA is 70% to 85%; 3) the molar content of the structural unit D in the second PSA is 5% to 20%; The pressure-sensitive adhesive composition according to claim 9 , which satisfies one or more of the following conditions:

13. The pressure-sensitive adhesive composition according to any one of claims 9 to 12, wherein the weight-average molecular weight of the first pressure-sensitive adhesive is 500,000 to 1,500,000, and further optionally, the difference in weight-average molecular weight between the first pressure-sensitive adhesive and the second pressure-sensitive adhesive is 100,000 to 1,500,000.

14. The pressure-sensitive adhesive composition according to any one of claims 9 to 13, further comprising an insulating filler and / or a dispersant, and optionally, a weight ratio of the insulating filler, the pressure-sensitive adhesive, and the dispersant is (70 to 90):(10 to 25):0.

4.

15. The insulating filler may include one or more of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, barium titanate, aluminum nitride, silicon nitride, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, mica, talc, boehmite, zeolite, apatite, kaolin, or glass powder, and optionally, the volume average particle size of the insulating filler may be D Ｖ The pressure-sensitive adhesive composition according to claim 14, wherein 50≦1 μm.

16. The pressure-sensitive adhesive composition according to claim 14 or 15, wherein the dispersant comprises one or more of a polyacrylate-based compound, an aliphatic alcohol polyether-based compound, or a polyether-modified siloxane-based compound.

17. The pressure-sensitive adhesive composition according to any one of claims 9 to 16, further comprising a solvent, optionally having a solids content of 20% to 40%, and further optionally comprising water as the solvent.

18. A positive electrode plate, a positive electrode current collector (11) having a positive electrode film layer region and a bare foil region on at least one side of the positive electrode current collector (11); a positive electrode film layer (12) disposed in the positive electrode film layer region of the positive electrode current collector (11); An insulating adhesive layer (13) disposed on the bare foil area of ​​the positive electrode current collector (11), A positive electrode plate comprising: an insulating adhesive layer (13) formed by employing the adhesive material according to any one of claims 1 to 8, or by curing the adhesive composition according to any one of claims 9 to 17.

19. The positive electrode plate according to claim 18, wherein the thickness of the insulating adhesive layer (13) is equal to or less than the thickness of the positive electrode film layer (12), and optionally the thickness of the insulating adhesive layer (13) is 3 μm to 7 μm.

20. A method for manufacturing a positive electrode plate, comprising a process for providing a positive electrode film layer and an insulating adhesive layer on at least one or both sides of a positive electrode current collector (11), wherein the process for providing the insulating adhesive layer (13) comprises: mixing the components of the adhesive substance according to any one of claims 1 to 8 or the adhesive composition according to any one of claims 9 to 17 to form an adhesive solution; coating the adhesive solution on a bare foil region of the positive electrode current collector to obtain a preform having the adhesive solution; Heating the preform with the adhesive solution to obtain the insulating adhesive layer, optionally the heating temperature is 90°C to 120°C; A manufacturing method comprising:

21. The process of mixing the components of the pressure-sensitive adhesive composition to form an adhesive solution comprises: mixing the dispersant in the PSA composition with water to form a first dispersion, optionally performing first stirring, the first stirring time being 5 minutes to 30 minutes, and the stirring speed being 200 rpm to 400 rpm; mixing the first dispersion with the insulating filler in the pressure-sensitive adhesive composition to form a second dispersion, optionally wherein the mixing is a second stirring, the second stirring time is 30 min to 120 min, and the stirring speed is 1200 rpm to 1800 rpm; mixing the second dispersion with the first PSA of the PSA composition to form a third dispersion, optionally comprising third stirring, a time period for the third stirring being 15 minutes to 60 minutes, and a stirring speed being 400 rpm to 700 rpm; 21. The method according to claim 20, further comprising: mixing the third dispersion with the second PSA in the PSA composition to form the adhesive solution; and optionally, the mixing is a fourth stirring, the fourth stirring is performed for a period of 5 minutes to 30 minutes, and the stirring speed is 200 rpm to 400 rpm.

22. A secondary battery including a positive electrode plate, the positive electrode plate comprising the positive electrode plate according to claim 18 or 19, or a positive electrode plate obtained by the manufacturing method according to claim 20 or 21.

23. 23. A power consuming device including a secondary battery, said secondary battery comprising the secondary battery of claim 22.

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