Coated films, membranes, and related methods

Abstract

An improved discontinuous aqueous adhesive coating is disclosed that contains large polymer particles or agglomerates having an average particle size (D50) greater than 5 microns. The coating can be applied to one or both sides of a porous membrane. The method of forming the coating involves applying an aqueous slurry containing large polymer particles having a D50 greater than 5 microns to a porous membrane. The method of application can be a spray method.

Description

Technical Field

[0001] This application relates to coated porous membranes, particularly coated porous or microporous battery separators. This application also relates to coating methods that can be used to form the coated porous membranes and / or coated porous or microporous battery separators disclosed herein. Background Technology

[0002] Waterborne adhesive coatings have been described. See, for example, U.S. Patents US2016 / 0164060 and US10,559,802, both attributed to Celgard, LLC. In these documents, the organic particles (e.g., PVDF particles) have an average particle size of less than 5 micrometers, preferably less than 2 micrometers, and in some cases less than 1 micrometer. Coatings with certain smaller particles may have an increased Gurley value, and therefore may have increased resistivity (ER). In some applications, products with higher Gurley values ​​and ER may not be preferred.

[0003] In the past, larger PVDF particles were only suitable for solvent-based coatings, such as acetone-based coatings, where PVDF powder was added instead of PVDF latex. Solvent-based coatings may not be preferred due to their negative environmental impact. Furthermore, with solvent-based coatings, the solvent becomes trapped in the pores, reducing porosity and increasing the Gurley value and resistivity (ER). Additionally, when solvent-based coatings are used on ceramic coating layers, the solvent allows PVDF to permeate into the ceramic coating and porous membrane. This is contrary to the expectation that PVDF should be held on the surface to provide bonding properties. Moreover, in solvent-based coatings, PVDF particles dissolve in the solvent and are therefore invisible in the resulting coating. This is because most PVDF is soluble in solvents but insoluble in water. In contrast, in water-based coatings, PVDF particles are visible in the resulting coating.

[0004] Therefore, it is desirable to avoid the negative effects of using solvent-based coatings, while also avoiding high Gurley values ​​and / or high ER. Summary of the Invention

[0005] The coatings described herein are preferably aqueous coatings, comprising large particles or agglomerates, for example, particles or agglomerates having an average particle size (D50) greater than 5 micrometers. These coatings have at least the following advantages: (1) they are environmentally friendly because no harmful solvents are used; (2) they avoid the low efficiency associated with powder-based coatings; (3) they reduce the increase in Gurley value, thereby reducing the ER of the resulting coated product; (4) the large particles can absorb a large amount of electrolyte, which can extend the battery cycle life; and (5) the large particles can penetrate the porous structure of the electrode and provide good adhesion in areas where smaller particles cannot penetrate, without causing a potentially significant increase in Gurley value.

[0006] In one aspect, a coated composite material is described. The composite material comprises, consists of, or is substantially composed of: (1) a porous membrane; and (2) a coating on at least one side of the porous membrane. The coating comprises, consists of, or is substantially composed of: a low-melting-point (T...)... m Polymers, low glass transition temperature (T) g ) polymers, or at least one combination thereof, forming particles or aggregates, wherein the T m The T ranges from about 20°C to about 170°C. g The temperature range is approximately -35°C to 60°C. The average particle size (D50) of the particles or agglomerates is 3 to 20 micrometers, 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. In some embodiments, the coating is an aqueous coating. In some embodiments, the coating is a discontinuous coating.

[0007] In some embodiments, the coating comprises low T g The polymer forms particles or aggregates, the T g The temperature ranges from approximately -40°C to 60°C, or from approximately -40°C to -30°C. In some embodiments, the particles or aggregates are formed from PVDF, PVDF-HFP, or combinations thereof.

[0008] The porous membrane of the composite material can be a microporous membrane, such as a polyolefin membrane, and in some embodiments, a dry-processed polypropylene or polyethylene membrane may be preferred. In selected embodiments, the composite material or microporous membrane is a battery separator.

[0009] In another aspect, another coated composite material is described. This composite material comprises, consists of, or is substantially composed of: (1) a porous membrane; and (2) a coating on at least one side of the porous membrane. The coating comprises, consists of, or is substantially composed of: acrylate particles or agglomerates having a high electrolyte swelling ratio with a weight variation of more than 200% or as high as more than 950% by weight. The average particle size (D50) of the particles or agglomerates is from 3 micrometers to about 20 micrometers, 5 micrometers to 20 micrometers, 5 micrometers to 15 micrometers, or 5 micrometers to 10 micrometers. In some embodiments, the coating is an aqueous coating. In some embodiments, the coating is a discontinuous coating.

[0010] In another aspect, a method for forming a coating is disclosed. This method comprises, consists of, or substantially comprises the step of applying an aqueous slurry to at least one surface of a porous membrane to form a coating. In some embodiments, the slurry comprises polymer particles or aggregates with an average particle size (D50) of 3 to 20 micrometers, 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. In some embodiments, the formed coating is a discontinuous coating. In some embodiments, a spraying method is used to apply the coating. The spraying method may be air spraying, airless spraying, or air-assisted spraying.

[0011] In some embodiments, the polymer particles or agglomerates in the slurry are composed of low melting point (T0). m Polymers, low glass transition temperature (T) g The T is formed from at least one of a polymer or a combination thereof, wherein the T m The T ranges from about 20°C to about 170°C. g The temperature range is approximately -35°C to 60°C. In some embodiments, the particles or aggregates are acrylate particles having a high electrolyte swelling ratio, with a weight ratio variation greater than 200% or as high as 950%. Attached Figure Description

[0012] Figure 1 The image is a scanning electron microscope image showing a top view of a composite material with a discontinuous aqueous coating of large polymer particles as described herein.

[0013] Figure 2 The image is a scanning electron microscope image showing a cross-sectional view of a composite material with a discontinuous aqueous coating of large polymer particles as described herein.

[0014] Figure 3 The image is a scanning electron microscope image showing a cross-sectional view of a composite material with a discontinuous aqueous coating of large polymer particles as described herein.

[0015] Figure 4 The image is a scanning electron microscope image showing a cross-sectional view of a comparative (prior art) coated film, wherein the coating is continuous and contains small polymer particles.

[0016] Figure 5 The image is a scanning electron microscope image showing a cross-sectional view of a comparative (prior art) coated film, wherein the coating is continuous and contains small polymer particles. Detailed Implementation

[0017] The embodiments described herein can be more readily understood by referring to the following detailed description, examples, and accompanying drawings. However, the elements, devices, and methods described herein are not limited to the specific embodiments presented in the detailed description, examples, and accompanying drawings. It should be recognized that the exemplary embodiments herein are merely illustrative of the principles of the invention. Many modifications and adaptations will readily become apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0018] Furthermore, all ranges disclosed herein should be understood to encompass any and all subranges contained herein. For example, the range “1.0 to 10.0” should be considered to include any and all subranges that begin with a minimum value of 1.0 or greater and end with a maximum value of 10.0 or less, such as 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.

[0019] All ranges disclosed herein should also be considered to include the endpoints of the range unless explicitly stated otherwise. For example, ranges such as “between 5 and 10”, “5 to 10”, or “5-10” should generally be considered to include the endpoints 5 and 10. Furthermore, when the phrase “up to” is used in conjunction with a quantity or amount, it should be understood that the quantity is at least a detectable quantity or amount. For example, material present in a quantity specified as “up to” can be present up to and include the specified quantity from a detectable quantity. Additionally, in any disclosed embodiment, the terms “substantially,” “about,” and “approximately” can be replaced with “within [percentage] of the specified value,” where percentages include 0.1%, 1%, 5%, and 10%.

[0020] The subject matter of this disclosure is specifically described herein to satisfy statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter may also be embodied in other ways to include different steps or combinations of steps similar to those described in this document, in combination with other current or future technologies. Furthermore, although the terms “step” and / or “block” may be used herein to denote different elements of the method employed, these terms should not be construed as implying any particular order among the various steps disclosed herein, unless and only when the order of the individual steps is explicitly described.

[0021] Unless otherwise specified, disjunctive language such as the phrase “at least one of X, Y, or Z” should be understood in the context as generally used to represent that items, terms, etc., can be X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z). Therefore, such disjunctive language is generally not intended and should not imply that some implementation requires at least one of X, at least one of Y, or at least one of Z to be present individually.

[0022] Coated composite materials

[0023] In one aspect, object, or embodiment, this document describes a coated composite material comprising: (1) a porous membrane; and (2) a coating provided on one or both sides of the porous membrane. In some embodiments, the coating is an aqueous coating. In some embodiments, the coating is a discontinuous coating. Further details are provided below.

[0024] (1) Porous membrane

[0025] The porous membrane of the composite material is not limited to this, and can be a nanoporous membrane, microporous membrane, mesoporous membrane, or macroporous membrane. In some preferred embodiments, the porous membrane can be a microporous membrane with an average pore size of less than 1 micrometer, less than 0.9 micrometers, less than 0.8 micrometers, less than 0.7 micrometers, less than 0.6 micrometers, less than 0.5 micrometers, less than 0.4 micrometers, less than 0.3 micrometers, less than 0.2 micrometers, less than 0.3 micrometers, less than 0.2 micrometers, less than 0.1 micrometers, less than 0.05 micrometers, less than 0.04 micrometers, less than 0.03 micrometers, less than 0.02 micrometers, or less than 0.01 micrometers.

[0026] In some preferred embodiments, the porous membrane may be a battery separator. Those skilled in the art will understand that not every porous membrane can serve as a separator. Some minimum requirements for a membrane to be a separator include: the porous membrane must be ionicly conductive, for example, lithium ions must be able to flow through the membrane, and the membrane must also be electrically insulating. Those skilled in the art will also understand that porous membranes with through-holes are not preferred for use as battery separators. This is because through-holes are considered defects in battery separators. Instead, porous membranes used as battery separators include tortuous pores.

[0027] The composition of the porous membrane is not limited thereto. In some preferred embodiments, the porous membrane comprises, consists of, or is substantially composed of thermoplastic polymers, such as polyolefins, like polyethylene, polypropylene, or combinations thereof. In some embodiments, a dry process (e.g., the Celgard dry process) can be used to form the porous membrane, which involves extruding a thermoplastic polymer without the use of plasticizers, oils, solvents, pore-forming agents, etc. In other embodiments, a wet process can be used. Wet processes use plasticizers, oils, solvents, pore-forming agents, or the like. It is known and understood that wet-process membranes and dry-process membranes have different structures.

[0028] The thickness of the porous membrane is not limited to this, and can range from 1 micrometer to 30 micrometers, preferably from 1 micrometer to 20 micrometers, more preferably from 1 micrometer to 15 micrometers, and most preferably from 1 to 10 micrometers.

[0029] (2) Coating

[0030] The thickness of the coating can be from about 1 micrometer to about 10 micrometers, from about 2 micrometers to about 10 micrometers, from about 3 micrometers to about 10 micrometers, from about 4 micrometers to about 10 micrometers, from about 5 micrometers to about 10 micrometers, from about 6 micrometers to about 10 micrometers, from about 7 micrometers to about 10 micrometers, from about 8 micrometers to about 10 micrometers, or from about 9 micrometers to about 10 micrometers.

[0031] In a preferred embodiment, the coating is a discontinuous coating. For example, the coating may include separated islands. These islands may have a size of >0 mm to about 3 mm.

[0032] In a preferred embodiment, the coating loading can be approximately 0.05 g / m². 2 Up to 1 g / m 2 Approximately 0.1 g / m 2 Up to 1 g / m 2 Approximately 0.2 g / m 2 Up to 1 g / m 2 Approximately 0.3 g / m 2 Up to 1 g / m 2 Approximately 0.4 g / m 2 Up to 1 g / m 2 Approximately 0.5 g / m 2 Up to 1 g / m 2 Approximately 0.6 g / m 2 Up to 1 g / m 2 Approximately 0.7 g / m 2 Up to 1 g / m 2 Approximately 0.8 g / m 2 Up to 1 g / m 2 or approximately 0.9 g / m 2 Up to 1 g / m 2 The range.

[0033] In some embodiments, the coating is applied directly to the surface of the porous membrane. However, in other embodiments, an intermediate coating may be present between the coating and the porous membrane. In some embodiments, one or more intermediate coatings may include a ceramic coating, a CVD coating or a PVD coating, a deposit or deposited layer, a mesh or nonwoven fabric, or a combination thereof. Furthermore, the porous membrane may have the same coating or treatment on both sides, have different coatings or treatments on each side, or have a coating or treatment on only one side.

[0034] In a preferred embodiment, the coating is an aqueous coating. As those skilled in the art will understand, an aqueous coating is a coating formed from a slurry (i.e., an aqueous slurry) using a solvent that is primarily water. The term "primarily water" means that the solvent is 90% or more, 95% or more, 98% or more, 99% or more, or 100% water. Solvents other than water may be added in amounts not exceeding 10%, preferably not exceeding 5%, and most preferably not exceeding 2% or 1% to improve the solubility of the slurry components in the solvent. Other solvents may also be added in amounts not exceeding 10%, preferably not exceeding 5%, and most preferably not exceeding 2% or 1% to improve the drying ability of the applied slurry and to form a coating. It should be understood that an aqueous coating may look different from a solvent-based slurry that includes the same components but a different solvent (e.g., acetone instead of water). This may be because the components are soluble in the solvent but insoluble in water, or vice versa. In coatings where the components (e.g., the polymer particles described herein) are insoluble in the solvent, different particles may be seen in the coating. When the components (e.g., the polymer particles described herein) are soluble in a solvent, discrete particles may not be visible in the final coating. Another difference between water-based and solvent-based coatings is that, after the slurry is applied and dried, water-based coatings typically will not have any residual solvent (e.g., acetone) remaining in the coating.

[0035] In some embodiments, the coating results in an increase in the Gurley value of 1 to 500 s, 1 to 450 s, 1 to 400 s, 1 to 250 s, 1 to 300 s, 1 to 250 s, 1 to 200 s, 1 to 150 s, 1 to 100 s, or 1 to 50 s. The increase is determined by measuring the Gurley value of the uncoated porous membrane, measuring the Gurley value of the porous membrane with a one-sided coating, and subtracting the Gurley value of the porous membrane with a one-sided coating from the Gurley value of the uncoated porous membrane. A smaller increase in the Gurley value caused by applying the coating is desirable. A smaller increase in the Gurley value generally equates to a more advantageous (i.e., lower) resistance. In embodiments where the coated composite material is used to coat a battery separator, such separators can be used in fast charge-discharge applications, such as 3C, EVs, power tools, etc. In such applications, a lower ER separator is preferred, as it reduces the battery's internal resistance. Without wishing to be bound by any particular theory, it is believed that the increase in the reduction of the Gurley value is due to the use of larger polymer particles and the application of discontinuous coatings.

[0036] In some preferred embodiments, the coating may exhibit a dry lamination bond strength between the separator and the electrode ranging from greater than 0 N / m to up to 50 N / m. In a preferred embodiment, the dry lamination bond strength between the separator and the electrode is 1 N / m or higher. Excessive bond strength may lead to self-adhesion between the coated porous membranes. As used herein, the term "dry bond" refers to the bond strength between the separator and the electrode prior to the addition of the electrolyte.

[0037] In a preferred embodiment, the coating comprises large polymer particles or aggregates with an average particle size (D50) of 3 to 20 micrometers, 5 to 20 micrometers, 6 to 20 micrometers, 7 to 20 micrometers, 8 to 20 micrometers, 9 to 20 micrometers, 10 to 20 micrometers, 11 to 20 micrometers, 12 to 20 micrometers, 13 to 20 micrometers, 14 to 20 micrometers, 15 to 20 micrometers, 16 to 20 micrometers, 17 to 20 micrometers, 18 to 20 micrometers, or 19 to 20 micrometers. In a preferred embodiment, the particles or aggregates have a D50 greater than 5 micrometers, which has not been previously used in waterborne coatings. Waterborne latexes, such as PVDF latex, available from suppliers and used in previous waterborne coatings, comprise much smaller particles (i.e., particles with a D50 in the range of 100 nm to 600 nm). Latex with larger particles tends to settle during transport, making it difficult to use.

[0038] In some preferred embodiments, the polymer particles or agglomerates are agglomerates composed of smaller particles. This can be seen in the following text. Figure 2 and Figure 3 As seen in the image, this structure allows the polymer particles to absorb electrolyte compared to similar, non-agglomerated polymer particles. The spaces between the smaller particles in the agglomerates can accommodate the electrolyte. Additionally, there is an increase in surface area associated with the agglomerated structure.

[0039] In a preferred embodiment, the large polymer particles or aggregates may be made from low-melting-point (T0) polymers. m Polymers, low glass transition temperature (T) g It is made of at least one of a polymer or a combination thereof, wherein the T m The T ranges from about 20°C to about 170°C. g Within a temperature range of approximately -35°C to 60°C. In some particularly preferred embodiments, low T mThe temperature can be from about 20°C to about 170°C, from about 30°C to about 170°C, from about 40°C to about 170°C, from about 50°C to about 170°C, from about 60°C to about 170°C, from about 70°C to about 170°C, from about 80°C to about 170°C, from about 90°C to about 170°C, from about 100°C to about 110°C, from about 120°C to about 170°C, from about 130°C to about 170°C, from about 140°C to about 170°C, from about 150°C to about 170°C, or from about 160°C to about 170°C. In some embodiments, low T g The temperatures can range from approximately -35°C to 60°C, approximately -30°C to 60°C, approximately -25°C to 60°C, approximately -20°C to 60°C, approximately -15°C to 60°C, approximately -10°C to 60°C, approximately -5°C to 60°C, approximately 0°C to 60°C, approximately 5°C to 60°C, approximately 10°C to 60°C, approximately 15°C to 60°C, approximately 20°C to 60°C, approximately 25°C to 60°C, approximately 30°C to 60°C, approximately 35°C to 60°C, approximately 40°C to 60°C, approximately 45°C to 60°C, approximately 50°C to 60°C, or approximately 55°C to 60°C. Low T g or low T m Examples of polymers include the following: polyethylene oxide (PEO), PVDF, PVDF-HFP, epoxy resin, PTFE, acrylic polymers (e.g., PMMA), polyacrylonitrile (PAN), polyurethane, silicone, or the like.

[0040] In other preferred embodiments, the large polymer particles or aggregates may be acrylate particles with a high electrolyte swelling ratio, wherein the high electrolyte swelling ratio is greater than 200%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, 300%, 350%, 400%, 450%, 500%, 550%, 600%, 650%, 700%, 750%, 800%, 850%, 900%, or 950% by weight. The high electrolyte swelling ratio was measured using a LiPF6-EC-EMC electrolyte at 30-70% by volume. The particles were immersed in the electrolyte for 15 hours. Weights were measured before and after 15 hours of immersion.

[0041] In addition to large polymer particles or aggregates, the coating may also include, consist of, or substantially consist of additional components including thickeners, binders, surfactants, dispersants, or combinations thereof. In some embodiments, the addition of thickeners may help prevent the settling of large polymer particles.

[0042] method

[0043] This document discloses a method for forming a coating. For example, in some embodiments, a method for forming a coating as described above regarding coated composite materials is described. This method may comprise, consist of, or substantially consist of: applying an aqueous slurry to at least one surface of a porous membrane to form a coating. In a preferred embodiment, the aqueous slurry comprises large polymer particles or aggregates with an average particle size (D50) ranging from 3 to 20 micrometers, 5 to 20 micrometers, 6 to 20 micrometers, 7 to 20 micrometers, 8 to 20 micrometers, 9 to 20 micrometers, 10 to 20 micrometers, 11 to 20 micrometers, 12 to 20 micrometers, 5 to 20 micrometers, 14 to 20 micrometers, 15 to 20 micrometers, 16 to 20 micrometers, 17 to 20 micrometers, 18 to 20 micrometers, or 19 to 20 micrometers. In a preferred embodiment, the polymer particles have a D50 greater than 5 micrometers. The large polymer particles or aggregates of the slurry are as described above regarding coatings. Aqueous slurries are as described above regarding coatings. Aqueous slurries may also include components other than the large polymer particles or aggregates and a solvent that is primarily water. For example, the slurry may further comprise, consist of, or substantially consist of additional components including thickeners, binders, surfactants, dispersants, or combinations thereof.

[0044] The method of applying the coating is not limited to this. In some embodiments, the coating can be applied by manual or automatic spraying. In other embodiments, air spraying can be used. In some embodiments, airless spraying, air-assisted spraying, or a dry process by charging the particles at the nozzle can also be used. Then, due to the electrostatic force between the particles and the porous membrane, the charged particles can adhere to the porous membrane.

[0045] In some embodiments, the coating formed by this method is a discontinuous coating as described above.

[0046] In some implementations, a further step of drying the applied slurry is performed.

[0047] Example

[0048] Example 1: In this example, a discontinuous aqueous PVDF-HFP coating was applied to one side of a 16-micron three-layer membrane (PP-PE-PP). The thickness of the coating ranged from 1 micron to 10 microns. The coating thickness varied due to the application and testing methods. The D50 of the PVDF-HFP particles in the coating ranged from 3 microns to 7 microns. The SEM image of Example 1 is shown below. Figure 1 , Figure 2 and Figure 3 As shown.

[0049] Example 2: This example is similar to Example 1, except that the coating load is higher. See Table 2.

[0050] Comparative Example 1: In this embodiment, a discontinuous aqueous PVDF-HFP coating is applied to one side of a 16-micron three-layer film (PP-PE-PP), and the thickness of the coating is approximately 1 to 5 microns. The PVDF-HFP particles in this embodiment are relatively small, with a D50 of 200 nm.

[0051] Comparative Example 2: This example is similar to Comparative Example 1, except that the coating is a continuous coating and has a thickness of 0.3 micrometers to 1 micrometer. The PVDF-HFP particles in this example are smaller, with a D50 of 200 nm.

[0052] Table 1 – Thickness Changes Before and After Lamination

[0053]

[0054] This indicates that after membrane lamination, the thickness significantly decreases from 0-10 μm to 0-2 μm. This result demonstrates coating penetration into the electrode, illustrating the reduction in laminate and membrane thickness after peeling, while the electrode thickness remains relatively constant.

[0055] Table 2 – Adhesion Strength Level

[0056]

[0057] An improved discontinuous aqueous adhesive coating is disclosed, comprising large polymer particles or aggregates with an average particle size (D50) greater than 5 micrometers. The coating can be applied to one or both sides of a porous membrane. The method of forming the coating involves applying an aqueous slurry containing large polymer particles with a D50 greater than 5 micrometers onto the porous membrane. The application method can be a spraying method.

[0058] Depending on the selected aspect, purpose, or implementation method, the improved discontinuous aqueous adhesive coating may be an ambient temperature or room temperature spray adhesive coating, a room temperature adhesive PVDF coating, or a discontinuous, aqueous, spray ambient temperature or room temperature adhesive PVDF or PVDF-HFP large particle coating or coating composite material, wherein the coating or coating composite material has a microporous membrane substrate or base membrane, and the coating may be located on one or both sides of the substrate or base membrane, and may be located on a ceramic coating on one or both sides of the substrate or base membrane, and the base membrane or substrate may be a polymer or polyolefin microporous membrane, a polyolefin monolayer microporous membrane, a multilayer polyolefin microporous membrane, a laminated polyolefin microporous membrane, a co-extruded polyolefin microporous membrane, or a combination thereof.

[0059] This application relates to coated porous membranes, particularly coated porous and / or microporous battery separators, and to a coating method for forming coated porous membranes and / or coated porous or microporous battery separators disclosed and / or claimed herein.

[0060] In some embodiments, the coating is applied directly to the surface of the porous membrane. However, in other embodiments, an intermediate coating may be present between the coating and the porous membrane. In some embodiments, one or more intermediate coatings may include a ceramic coating, a CVD coating or a PVD coating, a deposit or deposited layer, a mesh or nonwoven fabric, or a combination thereof. Furthermore, the porous membrane may have the same coating or treatment on both sides, have different coatings or treatments on each side, or have a coating or treatment on only one side.

[0061] An improved discontinuous aqueous adhesive coating is provided or described according to at least some embodiments, aspects, or purposes, comprising large polymer particles or aggregates with an average particle size (D50) greater than 5 micrometers. The coating can be applied to one or both sides of a porous membrane. A method of forming the coating involves applying an aqueous slurry containing large polymer particles with a D50 greater than 5 micrometers onto the porous membrane. The application method may be a spraying method.

[0062] However, the elements, devices, and methods described herein are not limited to the specific embodiments presented in the detailed descriptions, examples, and drawings. It should be understood that the exemplary embodiments described herein are merely illustrative of the principles of the invention. Many modifications and adjustments will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A composite material comprising: Porous membranes; and A discontinuous aqueous coating on at least one side of the porous membrane, The coating comprises a low melting point (T) m Polymers, low glass transition temperature (T) g Particles or aggregates formed from at least one of the polymers or combinations thereof, wherein the T m The T ranges from about 20°C to about 170°C. g Within the range of approximately -35°C to 60°C, and in which The average particle size (D50) of the particles or agglomerates is between 5 micrometers and 20 micrometers.

2. The composite material according to claim 1, wherein the porous membrane is a microporous membrane.

3. The composite material according to claim 1, wherein the porous membrane or the composite material is a battery separator.

4. The composite material according to claim 1, wherein the D50 of the particles or agglomerates is 5 micrometers to 15 micrometers.

5. The composite material according to claim 1, wherein the D50 of the particles or agglomerates is 5 micrometers to 10 micrometers.

6. The composite material of claim 1, wherein the coating comprises a low glass transition temperature (T0) g ) polymer particles or aggregates, wherein T g The temperature ranges from approximately -40°C to 60°C.

7. The composite material of claim 1, wherein the coating comprises a material with a low glass transition temperature (T0). g ) polymer particles or aggregates, wherein T g The temperature ranges from approximately -40°C to -30°C.

8. The composite material according to claim 1, wherein the particles or aggregates are formed of PVDF, PVDF-HFP, or a combination thereof.

9. A composite material comprising: Porous membranes; and An aqueous discontinuous coating on at least one side of the porous membrane, The coating comprises acrylate particles or agglomerates having a high electrolyte swelling ratio, with a weight ratio variation of more than 200% or as high as more than 950%, and an average particle size (D50) of 5 micrometers to 20 micrometers.

10. The composite material according to claim 9, wherein the D50 of the acrylate particles or agglomerates is 5 micrometers to 15 micrometers.

11. The composite material according to claim 9, wherein the D50 of the acrylate particles or agglomerates is 5 micrometers to 10 micrometers.

12. A method for forming a discontinuous coating, comprising: An aqueous slurry is applied to at least one surface of a porous membrane to form the coating, wherein the slurry comprises polymer particles or aggregates with an average particle size (D50) of 5 to 20 micrometers.

13. The method of claim 12, wherein the coating is discontinuous.

14. The method of claim 12, wherein the D50 of the particles is 5 micrometers to 15 micrometers.

15. The method of claim 12, wherein the D50 of the particles is 5 micrometers to 10 micrometers.

16. The method of claim 12, wherein the particles are composed of low melting point (T... m Polymers, low glass transition temperature (T) g The T is formed from at least one of a polymer or a combination thereof. m The T ranges from about 20°C to about 170°C. g The temperature ranges from approximately -35°C to 60°C.

17. The method of claim 12, wherein the particles are acrylate particles having a high electrolyte swelling ratio of more than 200% by weight or more than 950% by weight.

18. The method of claim 16, wherein the aqueous slurry is applied using a spraying method.

19. The method of claim 18, wherein the spraying method is an air spraying method.

20. The method of claim 18, wherein the method is an airless spraying method or an air-assisted spraying method.

21. The composite material according to claim 1, wherein the porous membrane is a microporous polyolefin membrane.

22. The composite material according to claim 9, wherein the porous membrane or the composite material is a battery separator.

23. The composite material according to claim 9, wherein the porous membrane is a microporous polyolefin membrane.

24. The method of claim 12, wherein the coated porous membrane is a composite material or a battery separator.

25. The method of claim 12, wherein the porous membrane is a microporous polyolefin membrane.

26. An improved discontinuous aqueous adhesive coating, ambient temperature or room temperature spray adhesive coating, room temperature adhesive PVDF coating, or discontinuous, aqueous, spray ambient temperature or room temperature adhesive PVDF or PVDF-HFP large particle coating or coating composite material, wherein the coating or coating composite material has a microporous membrane substrate or base membrane, and the coating can be located on one or both sides of the substrate or base membrane, and can be located on a ceramic coating on one or both sides of the substrate or base membrane, and the base membrane or substrate can be a polymer or polyolefin microporous membrane, a polyolefin monolayer microporous membrane, a multilayer polyolefin microporous membrane, a laminated polyolefin microporous membrane, a co-extruded polyolefin microporous membrane, or a combination thereof, as shown or described herein.

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