Porous membrane with coating, composite material, battery separator, battery and application

Abstract

A coated separator or a coated porous membrane comprises a separator and at least one coating, the coating comprises at least one selected from the group consisting of an adhesive, a shut-off agent and an adhesive, and the coating only contains a small amount of organic heat-resistant nanoparticles, the small amount being less than 1%, 5% or 10% of the total solid content in the coating; the coating is a water-based or water-based coating, and the water-based or water-based coating comprises a solvent which is water and up to 50% of an alcohol or non-organic water-soluble solvent. The partition plate itself is not a partition plate having a disconnection capability. According to the present invention, the separator exhibits a lower turn-off temperature compared to a separator containing standard size heat resistant particles. The composite material can be used for battery units, secondary batteries, capacitors, garment materials and the like.

Description

[0001] This application is a divisional application with a priority date of May 24, 2019; the original international application date was May 21, 2020; the original international application number was PCT / US2020 / 034046; the date of entry into the Chinese national phase was January 18, 2022, and the original Chinese application number was 202080052138.X; the original invention title was "Improved Coated Battery Separator and Battery". Technical Field

[0002] This application aims to improve battery separators, which provide enhanced safety, improved operational convenience, and improved ease of use in battery manufacturing, among other benefits. Background Technology

[0003] The ever-increasing performance standards, safety standards, manufacturing requirements, and / or environmental concerns make the development of new and / or improved coating compositions for battery separators desirable.

[0004] A major safety concern with lithium-ion batteries is thermal runaway. For example, improper usage conditions, such as overcharging, over-discharging, and internal short circuits, can cause battery temperatures to exceed the operating temperatures the battery manufacturer intends for its batteries to be used. Tests simulating improper usage conditions can include, but are not limited to, nail penetration tests and hot-box tests. Battery shutdown, for example, stopping the flow of ions through a separator, such as between the anode and cathode, in the event of thermal runaway, is a safety mechanism to prevent thermal runaway. In at least certain lithium-ion batteries, the separator must provide the ability to shut down at least slightly below the temperature at which thermal runaway occurs, while still maintaining its mechanical properties. For example, faster shutdown at lower temperatures and for a longer duration, giving users or devices more time to shut down the system, is highly desirable.

[0005] Celgard's U.S. Patent 5,952,120 (incorporated herein by reference in its entirety) discloses a three-layer shut-off partition. This partition exhibits shut-off capability at least due to its internal polyethylene layer. The polyethylene melts at temperatures close to its melting point and seals the pores of the partition. However, some partitions themselves do not possess the ability to shut off at low temperatures (e.g., about 135°C or lower). For example, a single-layer partition made of polypropylene may not shut off. Therefore, it is desirable to provide low-temperature shut-off capability for partitions that may not possess this capability themselves.

[0006] As the market demands increasingly thinner partitions, the ability to handle these very thin partitions becomes increasingly important. Therefore, there is a strong desire to create partitions that are easier to handle.

[0007] With the increasing demand for thinner separators, the ease with which battery separators can be used in the manufacture of battery cells is equally important. Therefore, there is a strong desire to create separators that can be easily used to manufacture a wide range of different battery cell types. Invention Overview

[0008] On one hand, this document describes coated separators or coated porous membranes. A coated separator or coated porous membrane comprises a separator or porous membrane and at least one coating, which includes, or is composed of, or substantially comprises at least one of the following: an adhesion agent, a shut-off agent, and a binder. In some embodiments, the coating does not contain any inorganic or organic heat-resistant particles, but in other embodiments, the coating may contain a small amount of inorganic and / or organic heat-resistant particles (less than 10% or less than 5% of total solids). In some embodiments, the coated separator or coated porous membrane may have another coating that does indeed include, or is composed of, or substantially comprises, more than a small amount of ceramic or inorganic or organic heat-resistant particles. This coating may be applied directly over a layer that does not contain more than a small amount of ceramic or organic or inorganic heat-resistant particles. However, this layer (which includes, or is composed of, or substantially comprises, at least one of the following: an adhesion agent, a shut-off agent, and a binder) does not contain more than a small amount of ceramic or organic or inorganic heat-resistant particles.

[0009] In some embodiments, the coating may comprise an adhesive, or consist of or substantially comprise an adhesive. In some embodiments, the coating may comprise an adhesive and a binder. The adhesive may comprise, or consist of or substantially comprise, at least one of the following: a wet adhesive and a dry adhesive. The wet adhesive may comprise, or consist of or substantially comprise, PVDF, an acrylic polymer, or a combination thereof. The dry adhesive may comprise a dry-adhesive polymer, or consist of or substantially comprise, the following: a PVDF-HFP copolymer or an acrylic substance having a glass transition temperature of less than 100°C (preferably between 30°C and 80°C). The adhesive may comprise, or consist of or substantially comprise, a dry adhesive alone, a wet adhesive alone, or a dry adhesive and a wet adhesive.

[0010] In some embodiments, the coating may comprise, or consist of, or substantially consist of, a shut-off agent. In some embodiments, the coating may comprise a shut-off agent and an adhesive. The shut-off agent may comprise, or consist of, or substantially consist of, beads or granules made of a polymer having a melting point of about 100°C to about 140°C. In some embodiments, PE beads having a melting point of 100°C to 140°C may be used. In some embodiments, the shut-off agent may comprise, or consist of, or substantially consist of, at least one of the following: beads or granules made of a polymer having a melting point of about 130°C to about 140°C, beads or granules made of a polymer having a melting point of about 80°C to about 130°C, beads or granules made of a polymer having a melting point of about 140°C to about 220°C, and combinations thereof.

[0011] In some embodiments, the coating may comprise, or consist of, or substantially comprise, an adhesive and a shut-off agent. In some embodiments, the coating may comprise, or consist of, or substantially comprise, an adhesive, a shut-off agent, and a binder. The adhesive may include a dry adhesive alone, a wet adhesive alone, or both a wet adhesive and a dry adhesive.

[0012] The coated separator or coated porous membrane can be a separator or porous membrane with a coating on one side, or a separator or porous membrane with a coating on both sides. For a separator or porous membrane with a coating on both sides, one or both sides may contain the coating as described herein, or one side may contain the coating as described herein, while the other side may contain a different coating. The different coatings may be, for example, ceramic coatings, polymer coatings, etc. Exemplary separators or porous membranes with coatings on one and both sides are shown below. Figure 1 As shown.

[0013] In some embodiments, the coated partition may be a partition that, without the coating, does not have shut-off capability at temperatures below 150°C or 140°C. In some embodiments, the partition without shut-off capability is a dry process partition. In some embodiments, the partition is composed of or substantially composed of polypropylene. In some embodiments, the partition is a single-layer polypropylene partition.

[0014] In some embodiments, the coated porous membrane can be a microporous, macroporous, or mesoporous porous membrane. The porous membrane can be a porous membrane formed by a dry process.

[0015] On the other hand, a battery cell comprising at least one coated separator as described herein is described. The battery may be at least one selected from cylindrical batteries, pouch batteries, prismatic batteries, wound batteries, folded batteries, wrapped batteries, pouch batteries, or stacked batteries.

[0016] On the other hand, a secondary battery comprising at least one coated separator as described herein is described.

[0017] On the other hand, a capacitor comprising at least one coated separator as described herein is described.

[0018] On one hand, this document describes a coated battery separator. The coated separator has at least one coating free of any ceramic or heat-resistant particles and comprises, or is composed of, or substantially comprises, an adhesive and a shut-off agent. In some embodiments, the coating may consist of an adhesive and a shut-off agent. In some embodiments, the coating may consist substantially of an adhesive, a shut-off agent, and an optional binder. In some embodiments, the coating may contain an adhesive, a shut-off agent, and an optional binder. In such embodiments, the coating may also contain other substances, but may add no more than a small amount (less than 10% of total solids) of ceramic or inorganic or organic heat-resistant particles. In some embodiments, the coating may not contain ceramic or organic heat-resistant particles.

[0019] In some embodiments, the coated separator may have another coating that does indeed contain, or consists of, or substantially consists of, more than a small amount of ceramic or inorganic or organic heat-resistant particles, but the layer containing, or consisting of, or substantially consists of, no more than a small amount of ceramic or organic or inorganic heat-resistant particles, preferably nanoparticles: an adhesive, a shut-off agent, and optionally a binder. For example, the ceramic coating may be disposed on one side of the separator or membrane opposite to the coating of the present invention, or may be disposed directly on top of the coating of the present invention. In the field of battery separators, particularly in the field of secondary lithium battery separators, the term ceramic coating is well known and typically includes ceramic particles (e.g., made using organic solvent PVDF binders or aqueous acrylic binders and alumina or boehmite particles) in an adhesive or polymer matrix, having 50% or more, 75% or more, 90% or more, or 95% or more of ceramic particles by volume or weight, and correspondingly 50% or less, 25% or less, 10% or less, or 5% or less of the adhesive or polymer matrix by volume or weight percentage. Today, many typical ceramic coatings have low binder content and contain more than 80%, 90%, or 95% by weight of ceramic, and a corresponding amount of less than 20%, 10%, or 5% binder or matrix (high ceramic content and low binder or polymer matrix content). In some embodiments, the coating may comprise, or consist of, or substantially consist of, the following: an adhesive, a shut-off agent, an optional binder, and small amounts of other components. For example, the other components may be at least one selected from antistatic agents. Antistatic agents may include inorganic or ceramic particles, such as carbon black, alumina, and / or the like.

[0020] In some embodiments, the adhesive may comprise, or consist of, or substantially consist of, at least one selected from dry adhesives, wet adhesives, and combinations thereof. In some embodiments, the adhesive may comprise, or consist of, or substantially consist of, a wet adhesive. In some embodiments, the adhesive may comprise, or consist of, or substantially consist of, a dry adhesive. In some embodiments, the adhesive may comprise, or consist of, a wet adhesive and a dry adhesive, or consist of, or substantially consist of, a wet adhesive and a dry adhesive. In some embodiments, the adhesive may comprise, or consist of, or substantially consist of, PVDF.

[0021] In some embodiments, the shut-off agent may comprise, or consist of, or be substantially comprised of, beads or particles made of a polymer having a melting point of about 100°C to about 140°C. In some embodiments, the shut-off agent may comprise, or consist of, or be substantially comprised of, PE beads. In some embodiments, the shut-off agent may comprise, or consist of, or be substantially comprised of: beads or particles made of a polymer having a melting point of about 130°C to about 140°C, beads or particles made of a polymer having a melting point of about 80°C to about 130°C, beads or particles made of a polymer having a melting point of 140°C to 220°C, and combinations thereof. The beads or particles may have an average particle size of 0.5 to 3 micrometers.

[0022] In some embodiments, the partition is composed of or substantially of polypropylene. In some embodiments, the partition composed of or substantially of polypropylene is a single-layer and / or dry process partition. In some embodiments, the partition is a partition that does not have shut-off capability without a coating, the coating comprising, or consisting of, or substantially consisting of, an adhesive and a shut-off agent. In some embodiments, the partition that does not have shut-off capability without a coating is a dry process partition.

[0023] In some embodiments, the coating may be on one side of the separator or porous membrane, while in other embodiments, it may be on both sides of the separator or porous membrane. Sometimes, the separator or porous membrane may include another coating that does indeed contain ceramic or heat-resistant particles.

[0024] On the other hand, this document describes a coated separator comprising a microporous membrane and a coating. In some embodiments, the coated separator shuts off before it shrinks by more than 15%, more than 12%, or more than 10% in at least its longitudinal or transverse dimensions (length and / or width). In some embodiments in which the coated separator shuts off before shrinking by more than 15%, more than 12%, or 10%, such a temperature is below 130°C, below 125°C, below 120°C, below 115°C, or below 110°C.

[0025] In some embodiments, the coating of the coated separator may comprise, or consist of, or substantially comprise, polyethylene and an adhesive. In some embodiments, the coating may also comprise, or substantially comprise, inorganic fine particles comprising 10% or less, or 5% or less of the total solids in the coating. The inorganic fine particles may comprise, or consist of, or substantially comprise, metal oxides having a D50 particle size of less than 500 nm, less than 250 nm or smaller, or less than 200 nm or smaller. In some embodiments, the metal oxide may comprise, or consist of, or substantially comprise, alumina. The coating may be applied to one or both sides of a porous or microporous film and may be applied directly or indirectly (i.e., through an intermediate layer) onto the porous or microporous film. For example, in some embodiments, the intermediate layer may be a ceramic layer.

[0026] In some embodiments, the porous microporous membrane may be a monolayer membrane. The monolayer membrane may comprise, or be composed of, or substantially comprise, polypropylene. The microporous membrane may have an average porosity greater than 30%. The microporous membrane may have an average pore size greater than 0.03 micrometers, greater than 0.04 micrometers, greater than 0.045 micrometers, or larger. In some embodiments, the microporous membrane may be a bilayer, trilayer, or multilayer microporous membrane.

[0027] On the other hand, a secondary battery is described, which includes at least one coated battery separator as described herein.

[0028] On the other hand, a capacitor is described that comprises a coated battery separator containing a coated porous membrane as described herein.

[0029] In another aspect, a composite material is described comprising a coated battery separator with a coated porous membrane as described herein, having an additional layer directly on top of the coating. In such embodiments, the coating may be a coating comprising an adhesive, or a coating consisting of or substantially comprising an adhesive. The coating may be a coating comprising an adhesive and a binder, or a coating consisting of or substantially comprising an adhesive and a binder. The coating may be a coating comprising, or consisting of, or substantially comprising, an adhesive, a binder, and a small amount of inorganic or organic particles. The coating may be an aqueous or water-based coating. The additional coating directly disposed on top of the coating may be a ceramic coating, a polymer coating, a coating comprising an electrode material, or a coating consisting of or substantially comprising an electrode material, a coating comprising a solid electrolyte material, or a coating consisting of or substantially comprising a solid electrolyte material, a metal coating, a metal layer, a metal-containing coating, and / or the like. Attached Figure Description

[0030] Figure 1This is a schematic diagram of a battery separator with a layered membrane on one side and coatings on both sides.

[0031] Figure 2 These are shutdown curves based on some of the implementation methods described herein.

[0032] Figure 3 This is a schematic diagram of a typical porous membrane structure produced by dry processing.

[0033] Figure 4 A and Figure 4 B is the FSEM of a typical dry process membrane as described in this article.

[0034] Figure 5 This is a diagram illustrating the concept of curvature.

[0035] Figure 6 This is a schematic diagram of a typical lithium-ion battery.

[0036] Figure 7 This is a schematic diagram of a coated partition or a coated membrane according to some embodiments described herein.

[0037] Figure 8 This is a schematic diagram of a coated membrane and a coated separator according to some embodiments described herein.

[0038] Figure 9 Schematic diagrams of some coated partitions or coated membranes according to some embodiments described herein.

[0039] Figure 10 Schematic diagrams of some coated partitions or coated membranes according to some embodiments described herein.

[0040] Figure 11 SEM images of solvent-based and water-based or aqueous coatings according to some embodiments described herein are included. The SEM images highlight the uniformity of the aqueous or aqueous coatings.

[0041] Figure 12 This is a diagram illustrating self-adhesion in some of the embodiments described herein.

[0042] Figure 13 This is a schematic diagram of the proposed mechanism, which explains why self-adhesion is reduced in some of the embodiments described herein.

[0043] Figure 14 This is a graph showing the shutdown curves of some of the embodiments described herein.

[0044] Figure 15 SEM images of some of the embodiments described herein.

[0045] Figure 16 These are schematic diagrams of some of the implementation methods described in this article. Detailed Implementation

[0046] This document describes coated separators or coated porous membranes. In a preferred embodiment, the coated separator or coated porous membrane has a coating comprising, or consisting of, or substantially consisting of, at least one selected from adhesives, shut-off agents, and binders. The coating does not contain ceramic or heat-resistant materials, or contains only a small amount of such materials. In some preferred embodiments, the coating may comprise an adhesive, a shut-off agent, and one or more additional components. In other preferred embodiments, the coating may consist of, or substantially consist of, an adhesive and a shut-off agent. In some embodiments, the coating may comprise one of the following combinations: an adhesive; an adhesive and a binder; a shut-off agent; a shut-off agent and a binder; a shut-off agent and a binder; and a shut-off agent, an adhesive, and a binder. In any of the foregoing combinations, the adhesive may comprise: multiple wet adhesives or only one wet adhesive; multiple dry adhesives or only one dry adhesive; a combination of at least one wet adhesive and at least one dry adhesive.

[0047] The coating can be applied to one or both sides of the separator or porous membrane. In some preferred embodiments where the coating is applied to both sides, the coating is applied to two opposite sides of the separator or porous membrane. This is as follows: Figure 1 As shown.

[0048] In some embodiments, the coated separator or coated porous membrane described herein may comprise a coating different from the aforementioned coating, which comprises, or is composed of, or substantially comprises at least one selected from adhesives, shut-off agents, and binders. For example, a double-coated separator may have a coating on one side comprising, or is composed of, or substantially comprises at least one selected from adhesives, shut-off agents, and binders, while having a different coating on the other side. For example, this different coating may be a ceramic coating.

[0049] coating

[0050] The coating described herein may comprise, or consist of, or substantially consist of, at least one of the following: (1) a shut-off agent, (2) an adhesive, and (3) a binder. In some preferred embodiments, the coating does not contain ceramic or other heat-resistant inorganic or organic materials. In some embodiments, the coating may further comprise, or consist of, or substantially consist of, a small amount (less than about 10% or less than 5% of total solids) of ceramic or other heat-resistant organic or inorganic materials for purposes such as providing antistatic effects. Although the coating described herein may contain a certain amount of ceramic or other organic or inorganic heat-resistant materials, this coating is not a typical ceramic coating, which typically contains 90% or 95% or more by weight of ceramic or other inorganic or organic heat-resistant materials. In some embodiments, the coating may comprise: a shut-off agent; a shut-off agent and an adhesive; an adhesive; an adhesive and a binder; a shut-off agent and an adhesive; a shut-off agent, an adhesive, and a binder. In any of the foregoing embodiments, the adhesive may comprise, or consist of, or substantially consist of: only one wet adhesive or multiple wet adhesives; only one dry adhesive or multiple dry adhesives; or at least one dry adhesive and at least one wet adhesive.

[0051] In some other embodiments, the coating may comprise, or consist of, or substantially consist of, the following: a polyethylene shut-off agent or a polyethylene shut-off agent having a binder and optional inorganic fine particles. There are few limitations on the polyethylene; it may include any polyethylene, including those described herein, particularly the lower melting point polyethylenes described herein. There are few limitations on the binder; it may be any binder described herein. There are few limitations on the inorganic fine particles; they may be or include any other inorganic materials described herein. The inorganic fine particles may be nanoparticles and have an average particle size of less than about 500 nm, less than 450 nm, less than 400 nm, less than 350 nm, less than 300 nm, less than 250 nm, less than 225 nm, less than 200 nm, less than 175 nm, less than 150 nm, less than 125 nm, or smaller. In some embodiments, the particle size may be greater than 250 nm and up to 1,000 nm. In some embodiments described herein, smaller particle sizes are advantageous, particularly for the shut-off coatings described herein and for some of the adhesive coatings described herein. For example, and without wishing to be bound by any particular theory, it is believed that inorganic fine particles may be preferred for coatings containing shut-off agents because the shut-off agents can more easily flow and clog the pores of the septum or porous membrane, thereby causing shut-off. In some embodiments, the inorganic fine particles may comprise, or consist of, or be substantially composed of, metal oxides. In some embodiments, the metal oxide may be alumina or an oxide of aluminum. In some embodiments, the metal oxide may be another metal oxide besides alumina, including the metal oxides disclosed herein. The inorganic fine particles may be present in amounts less than 10% of the total solids content of the coating, less than 9% of the total solids content of the coating, less than 8% of the total solids content of the coating, less than 7% of the total solids content of the coating, less than 6% of the total solids content of the coating, less than 5% of the total solids content of the coating, less than 4% of the total solids content of the coating, less than 3% of the total solids content of the coating, less than 2% of the total solids content of the coating, or less than 1% of the total solids content of the coating.

[0052] The coating may have a thickness of 0.5 to 10 micrometers, 0.5 to 9 micrometers, 0.5 to 8 micrometers, 0.5 to 7 micrometers, 0.5 to 6 micrometers, 0.5 to 5 micrometers, 0.5 to 4 micrometers, 0.5 to 3 micrometers, or 0.5 to 2 micrometers. In some preferred embodiments, the coating may be about 1 to about 2 micrometers thick. In some embodiments, the coating may be a single layer.

[0053] The coating can be provided using any known method. It can also be formed via a co-extrusion process, in which the separator and coating are co-extruded together.

[0054] In some preferred embodiments, the coating is applied directly to the surface of the partition; however, in other embodiments, an intermediate layer may be provided between the partition and the coating. For example, Figure 9 An example with an intermediate ceramic layer is shown. One or more other layers can be disposed on top of the coating. For example, a layer containing inorganic or organic heat-resistant particles can be disposed on top of this layer. Furthermore, a ceramic layer, a layer containing electrode materials, a layer containing solid electrolyte materials, a metal layer, a metal-containing layer, or the like can be disposed directly on top of the coating. This is in... Figure 16 As shown in [the image]. Figure 16 In this process, the coating is preferably an adhesive or viscous coating, but the coating may also contain a shut-off agent and / or organic or inorganic particles, including nanoparticles.

[0055] There are few restrictions on the size, shape, chemical composition, etc. of these heat-resistant particles. Heat-resistant particles may include organic materials, inorganic materials (such as ceramic materials), or composite materials (which include inorganic and organic materials, two or more organic materials and / or two or more inorganic materials).

[0056] In some embodiments, heat resistance means that the material made of particles (which may include composites made of two or more different materials) does not undergo significant physical changes, such as deformation, at a temperature of 200°C. Exemplary materials include alumina (Al₂O₃), silicon dioxide (SiO₂), graphite, etc.

[0057] Non-limiting examples of inorganic materials that can be used to form the heat-resistant particles disclosed herein include: iron oxide, silicon dioxide (SiO2), aluminum oxide (Al2O3), boehmite [Al(O)OH)], zirconium dioxide (ZrO2), titanium dioxide (TiO2), barium sulfate (BaSO4), barium titanium oxide (BaTiO3), aluminum nitride, silicon nitride, calcium fluoride, barium fluoride, zeolite, apatite, kaolin, aluminum-rich andalusite, spinel, olivine, mica, tin dioxide (SnO2), indium tin oxide, oxides of transition metals, graphite, carbon, metals, and any combination thereof.

[0058] Non-limiting examples of organic materials that can be used to form the heat-resistant particles disclosed herein include: polyimide resins, melamine resins, phenolic resins, polymethyl methacrylate (PMMA) resins, polystyrene resins, polydivinylbenzene (PDVB) resins, carbon black, graphite, and any combination thereof.

[0059] Heat-resistant particles can be round, irregularly shaped, flake-like, etc. The average particle size range of heat-resistant materials is 0.01 to 5 micrometers, 0.03 to 3 micrometers, 0.01 to 2 micrometers, 0.5 to 3 micrometers, etc.

[0060] In some preferred embodiments, the coating may be a water-based or aqueous coating. Water-based means the coating is formed from a coating slurry in which the solvent is only water, or water and alcohol or other non-organic water-soluble solvents. For example, a water-based or aqueous coating may include a solvent that is water and up to 50% alcohol or a non-organic water-soluble solvent, such as PVA. In some embodiments, the coating may be a solvent-based coating. Solvent-based coatings are formed from a slurry in which the solvent is an organic solvent. Sometimes, the solvent is present along with the adhesive used. Most solvents are removed from the coating after it has been formed from the coating slurry.

[0061] (1) Shut-off agent

[0062] There are few limitations on the shut-off agent. In some embodiments, the shut-off agent may be able to provide at least one of the following functions: (1) imparting low-temperature (e.g., less than 135°C) shut-off capability to a septum that does not have low-temperature shut-off capability without the coating; (2) reducing the shut-off initiation temperature of a septum that does have low-temperature shut-off capability; and (3) widening the shut-off window of a septum that has low-temperature shut-off capability. All shut-off agents described herein can be used with or without low-temperature shut-off capability, although the use of a particular shut-off agent may be superior to other shut-off agents.

[0063] Regarding the use of the shut-off agents disclosed herein, it may be preferred to use such shut-off agents that impart cryogenic shutdown to a separator that does not itself exhibit cryogenic shutdown function. However, shut-off agents that lower the shutdown onset temperature or widen the shutdown window can also be used to provide a wider shutdown window. Examples of separators that do exhibit cryogenic shutdown function can be found in Celgard's U.S. Patent US5,952,120, which is incorporated herein by reference in its entirety. In that document, shutdown is provided at least in part by the melting of a polyethylene-containing intermediate layer of a three-layer structure. In such a shutdown three-layer structure, because PE shutdown also contributes to increasing the strength of the film, there is generally a lower limit on the melting point and molecular weight of the polyethylene used. Lower molecular weight (and therefore lower melting point) polyethylene is generally not used because it cannot provide the same mechanical strength as higher molecular weight (and therefore higher melting point) polyethylene. However, when providing shutdown in a coating as done herein, lower molecular weight (and therefore lower melting point) polyethylene can be used as a shut-off agent for the coating, which does not necessarily provide mechanical strength to the separator. The coatings described herein can also be set as... The shutdown three-layer structure disclosed in US Patent 5,952,120 provides a "double shutdown" effect, where shutdown may begin at the melting point of the shutdown agent, which is typically below the melting point of the polymer used in the shutdown layers of the shutdown three-layer structure. By providing the separator with a lower-temperature shutdown capability, the safety of batteries using separators is improved. For example, thermal runaway can be better prevented.

[0064] In some embodiments, the shut-off agent may be in the form of microparticles or beads. The microparticles or beads may have an average particle size of 0.1 to 3 micrometers, 0.1 to 2 micrometers, 0.1 to 1.5 micrometers, 0.1 to 1.0 micrometers, 0.5 to 3.0 micrometers, or 0.1 to 0.5 micrometers. The particles or beads may be symmetrical, asymmetrical, spherical, or non-spherical.

[0065] In embodiments where the shut-off agent can provide cryogenic shut-off capability to a partition without a coating and therefore without cryogenic shut-off capability, the shut-off agent may comprise, or consist of, or substantially consist of, a polymer having a melting point of about 135°C or below. In some embodiments, the polymer may have melting points below about 130°C, below about 125°C, below about 120°C, below about 115°C, below about 110°C, below about 105°C, below about 100°C, below about 95°C, or below about 90°C. In some embodiments, the polymer may have a melting point in the range of 80°C to 135°C. In some embodiments, the shut-off agent may comprise, or consist of, or substantially consist of, polymer beads. In some preferred embodiments, the shut-off agent may comprise, or consist of, or substantially consist of, polyethylene beads.

[0066] In embodiments where the shut-off agent lowers the diaphragm's shut-off initiation temperature, the diaphragm will exhibit similar behavior to... Figure 2 The turn-off curve shown is the turn-off curve.

[0067] In such an implementation, the shut-off agent will have a melting point that is 1, 2, or 3 degrees below the shut-off initiation temperature of the separator itself. For example, the shut-off agent may comprise, or be composed of, or substantially comprise, a polymer having a melting point from 80°C to a value lower than the shut-off initiation temperature measured on the separator itself (i.e., without coating). Alternatively, the shut-off agent may comprise, or be composed of, or substantially comprise, a polymer having a melting point within 1, 2, or 3 degrees of temperature from 80°C to the shut-off initiation temperature of the separator itself. Exemplary materials may include particles or beads comprising waxes, oligomers, polyethylene (PE, such as low-density PE), and / or the like. These particles may be coated, uncoated, or partially coated.

[0068] In an embodiment where the shut-off agent widens the shut-off window of a septum with shut-off capability, the septum will exhibit the following characteristics: Figure 2The shutdown window is shown. In such embodiments, the shutdown agent may comprise a polymer with a melting point above the shutdown temperature. For example, in these embodiments, the shutdown agent may have a melting point above 135°C. For example, the shutdown agent may have a melting point in the range of 140°C to 220°C, sometimes in the range of 150°C to 200°C, sometimes in the range of 160°C to 190°C, sometimes in the range of 170°C to 180°C, and so on.

[0069] (2) Adhesive

[0070] There are few limitations on the adhesives described herein. In some embodiments, the adhesive is at least one selected from the group consisting of wet adhesives, dry adhesives, and combinations thereof.

[0071] In some embodiments, the adhesive is in the form of beads or particles and has an average particle size of 0.1 to 3 micrometers, 0.1 to 2 micrometers, 0.1 to 1.5 micrometers, 0.1 to 1.0 micrometers, 0.5 to 3 micrometers, or 0.1 to 0.5 micrometers. The beads or particles may be spherical, symmetrical, or asymmetrical in shape.

[0072] In some preferred embodiments, the wet adhesive may comprise, or consist of, or be substantially composed of, a wet adhesive polymer. There are few limitations on the wet adhesive polymer described herein; it can be any polymer that absorbs electrolyte, swells or increases in size when absorbing electrolyte, and / or becomes gel-like when absorbing electrolyte. The electrolyte can be any electrolyte suitable for use in a secondary battery, including but not limited to electrolytes in which the solvent is DEC, PC, DMC, EC, or combinations thereof. When wetted by the electrolyte, the wet adhesive polymer will also increase the adhesion of the coating to the anode or cathode of the secondary battery.

[0073] In some embodiments, the wet-adhesive polymer may comprise, or consist of, or be substantially composed of, a fluoropolymer. In some embodiments, the fluoropolymer is PVDF, such as PVDF-HFP. The HFP content of PVDF-HFP may be 1 to 50% by weight, based on the total weight of the polymer. In some embodiments, it may be 1 to 40% by weight, 1 to 30% by weight, 1 to 20% by weight, 1 to 15% by weight, 1 to 10% by weight, or 1 to 5% by weight.

[0074] In some embodiments, the wet adhesive polymer may comprise, or consist of, or substantially consist of, the following: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, sec-butyl methacrylate, amyl methacrylate, 2-ethylbutyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, isononyl methacrylate, and so on. Lauryl acrylate, tetradecyl methacrylate, polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF:HFP), polytetrafluoroethylene (PTFE), polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylamide, polyvinyl acetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polypropylene (PP, including isotactic PP, high-density PP, ultra-high molecular weight PP, low-density PP), polyethylene (PE, including high-density PP)

[0075] PE, ultra-high molecular weight PE, low density PE), polyvinyl acetate, polyvinyl chloride, bisphenol A polycarbonate (BPA-PC), cyclic olefin copolymer (COC), polysulfone (PSF), polyetherimide (PEI), polyurethane, acrylonitrile butadiene styrene (ABS), copolymers of any of the above substances, or any combination thereof.

[0076] In batteries where electrode adhesion is critical, the use of wet-adhesive polymers may be useful.

[0077] In some preferred embodiments, the adhesive is a wet-adhesive polymer as described herein, or is composed of or substantially composed of a wet-adhesive polymer as described herein. In some preferred embodiments, PVDF is a wet-adhesive polymer. In some embodiments, the wet-adhesive polymer is an acrylic polymer.

[0078] In some preferred embodiments, the dry adhesive may comprise, or consist of, or be substantially composed of, a dry adhesive polymer. There are few limitations on the dry adhesive polymers described herein; any polymer that imparts high or low tack to the coating. High-tack coatings are more difficult to separate after contact with another bonded surface. Lower-tack coatings are easier to separate and reposition after contact with another bonded surface. For example, a tacky coating may be beneficial for battery separators used in stacked or prismatic batteries. Once the separator is in place within the battery, it helps prevent separator movement.

[0079] The dry-adhesion polymers described herein possess characteristics related to their glass transition temperatures. In some embodiments, the dry-adhesion polymers have glass transition temperatures below 100°C, below 90°C, below 80°C, below 70°C, below 60°C, below 50°C, below 40°C, below 30°C, or below 20°C. The minimum glass transition temperature can be 20°C, 10°C, 5°C, or 0°C. Preferably, in some embodiments, the glass transition temperature can be 20°C to 100°C, 20°C to 70°C, or 25°C to 100°C. In some embodiments, the dry-adhesion polymers have glass transition temperatures below 100°C, below 90°C, below 80°C, or below 70°C. In some preferred embodiments, the glass transition temperature of the dry adhesive polymer is between 30°C and 80°C, between 40°C and 70°C, between 40°C and 65°C, between 45°C and 60°C, between 45°C and 55°C, or between 45°C and 50°C.

[0080] Some non-limiting examples of dry-adhesion polymers may be PVDF-HFP copolymers or acrylic acid having the glass transition temperatures described above. In some embodiments, the HFP content in the PVDF-HFP may be 1 to 50%, 1 to 40%, 1-30%, 1-20%, 1-10%, or 1 to 5% by weight of the total polymer. In some embodiments, the dry-adhesion polymer may be an acrylic polymer.

[0081] In embodiments where the adhesive includes dry-adhesive polymers and wet-adhesive polymers, the benefits of using these types of polymers can be realized (e.g., adhesion to one or more electrodes, and ease of fabrication of stacked or prismatic batteries). In some embodiments, ceramic coatings, electrode materials, metals, metallic materials, or solid electrolyte materials can be applied directly to a coating containing an adhesive.

[0082] (3) Adhesive

[0083] There are not many restrictions on adhesives.

[0084] In some embodiments, the adhesive may be acrylic acid. In some embodiments, the adhesive may be a polymeric adhesive, comprising, or consisting primarily of, a polymer, oligomer, or elastomeric material, and is similarly not highly limited. Any polymer, oligomer, or elastomeric material that does not contradict this disclosure may be used. The adhesive may be ionicly conductive, semi-ionicly conductive, or non-ionicly conductive. Any gel-forming polymer suggested for lithium polymer batteries or solid electrolyte batteries may be used. For example, the polymeric adhesive may include at least one, two, or three selected from: polylactam polymers, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl acetate (PVAc), carboxymethyl cellulose (CMC), isobutylene polymers, acrylic resins, latex, aramid fibers, or any combination of these materials.

[0085] In some preferred embodiments, the polymeric adhesive comprises, or is composed of, or is substantially composed of, a polylactam polymer, which is a homopolymer, copolymer, block polymer, or block copolymer derived from lactam. In some embodiments, the polymeric material comprises a homopolymer, copolymer, block polymer, or block copolymer according to formula (1).

[0086]

[0087] Wherein, R1, R2, R3, and R4 can be alkyl or aromatic substituents, and R5 can be an alkyl substituent, an aryl substituent, or a substituent containing a fused ring; and wherein the preferred polylactam can be a homopolymer or copolymer in which the copolymer group X can be derived from vinyl, substituted or unsubstituted alkyl vinyl, vinyl alcohol, vinyl acetate, acrylic acid, alkyl acrylate, acrylonitrile, maleic anhydride, maleimide, styrene, polyvinylpyrrolidone (PVP), polyvinylcaprolactam, polyvinylcaprolactam (PVCap), polyamide, or polyimide; wherein m can be an integer between 1 and 10, preferably between 2 and 4, and wherein the ratio of l to n is such that 0 ≤ l: n ≤ 10 or 0 ≤ l: n ≤ 1. In some preferred embodiments, the homopolymer, copolymer, block polymer, or block copolymer derived from the lactam is selected from at least one, at least two, or at least three of the following: polyvinylpyrrolidone (PVP), polyvinylcaprolactam (PVCap), and polyvinylcaprolactam.

[0088] In another preferred embodiment, the polymeric adhesive comprises, or is composed of, or is substantially composed of, polyvinyl alcohol (PVA). The use of PVA produces a low-curl coating, which helps the substrate to which it is applied remain stable and flat, for example, helping to prevent substrate curling. PVA can be added in combination with any other polymers, oligomers, or elastic materials described herein, particularly where low curl is required.

[0089] In another preferred embodiment, the polymeric adhesive may comprise, or consist of, or be substantially composed of, an acrylic resin. There is no particular limitation on the type of acrylic resin; it may be any acrylic resin that does not contradict the objectives set forth herein (e.g., providing new and improved coating compositions that can, for example, be used to manufacture battery separators with improved safety). For example, the acrylic resin may be selected from at least one, two, three, or four of the following: polyacrylic acid (PAA), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), and polymethyl methacrylate (PMA).

[0090] In other preferred embodiments, the polymeric adhesive may comprise, or consist of, or substantially consist of, carboxymethyl cellulose (CMC), isobutylene polymers, latex, or any combination thereof. These substances may be added alone or together with any other suitable oligomers, polymers, or elastomeric materials.

[0091] In some embodiments, the polymeric adhesive may contain solvents such as water only, aqueous or water-based solvents, and / or non-aqueous solvents. When the solvent is water, in some embodiments, no other solvents are present. Aqueous or water-based solvents may contain a majority (more than 50%), more than 60%, more than 70%, more than 80%, more than 90%, more than 95%, or more than 99%, but less than 100% water. In addition to water, aqueous or water-based solvents may contain polar or non-polar organic solvents. There are no limitations on non-aqueous solvents; they may be any polar or non-polar organic solvent compatible with the objectives expressed herein. In some embodiments, the polymeric adhesive contains only trace amounts of solvent, while in other embodiments, the polymeric adhesive contains 50% or more solvent, sometimes 60% or more, sometimes 70% or more, sometimes 80% or more, and so on.

[0092] In some preferred embodiments, the amount of adhesive may be less than 20%, less than 15%, less than 10%, or less than 5% of the total solids in the coating. In some particularly preferred embodiments, the amount of adhesive may be 10% or less, or 5% or less of the total solids in the coating.

[0093] Separator or porous membrane

[0094] There are few limitations on the battery separator (without coating) or porous membrane described herein, and any battery separator or porous membrane can be used. For example, the separator or porous membrane can be a single-layer, double-layer, triple-layer, or multi-layer separator or porous membrane made by any type of process, including dry and wet processes known in the art.

[0095] In a preferred embodiment, the separator is porous, nanoporous, microporous, or macroporous. In some particularly preferred embodiments, the separator is microporous. For example, the separator may have an average pore size between 0.1 and 1.0 micrometers.

[0096] In some preferred embodiments, the separator or membrane is one that does not itself have shutdown capability. For example, the separator does not have shutdown capability at temperatures below 160°C, below 150°C, or below 140°C. For example, in some embodiments, the separator is not a three-layer shutdown separator as disclosed in Celgard U.S. Patent No. 5,952,120. However, in some embodiments, the separator itself may have shutdown capability (e.g., at temperatures below 160°C, below 150°C, or below 140°C), and the coating may be used to lower the shutdown initiation temperature or widen the shutdown window.

[0097] In some preferred embodiments, the partition is a single-layer partition.

[0098] In some preferred embodiments, the battery separator described herein is a dry-process battery separator or membrane.

[0099] In some embodiments, the dry process is a process that does not use any pore-forming reagents / agents or β-nucleating reagents / agents. In some embodiments, the dry process is a process that does not use any solvents, waxes, or oils. In some embodiments, the dry process is a process that does not use any pore-forming reagents / agents or β-nucleating reagents / agents, nor does it use any solvents, waxes, or oils. In such embodiments, the dry process can be a dry stretching process. (From Chen et al.'s...) Structural Features of Microporous Membrane Precursors: Melt Extrusion of Polyethylene Films (J. of Applied Polymer Sci., vol. 53, 471-483 (1994)) describes an exemplary dry stretching process, referred to as the Celgard dry stretching process, which is incorporated herein by reference in its entirety. The Celgard dry stretching process refers to a process in which pores are formed by stretching a non-porous oriented precursor in at least the processing direction. A dry stretching process is also disclosed in Synthetic Polymeric Membranes, Astructural Perspective, edited by Kesting and Robert E. (2nd edition, John Wiley & Sons, New York, NY, (1985), pp. 290-297), which is incorporated herein by reference in its entirety. In a dry stretching process according to some preferred embodiments, the process may include a stretching step. The stretching step may include, or consist of, or substantially consist of, the following: uniaxial stretching (e.g., stretching only in the MD direction or only in the TD direction), biaxial stretching (e.g., stretching in both the MD and TD directions), or multiaxial stretching (e.g., stretching along three or more different axes (e.g., MD, TD, and another axis)). In some embodiments, the dry stretching process may include, or consist of, or substantially consist of, extrusion and stretching steps, in that order or not. In some embodiments, the dry stretching process may include, or consist of, or substantially consist of, extrusion, annealing, and stretching steps, in that order or not. In some embodiments, the extrusion step may be a blown film extrusion step or a cast film extrusion process. In some embodiments, a non-porous precursor is extruded and stretched to form a hole. In some embodiments, a non-porous precursor is extruded, annealed, and subsequently stretched to form a hole. In other embodiments, porous or non-porous precursors may be formed by methods other than extrusion, such as by sintering or printing, and the precursor may be stretched to form a hole or to enlarge an existing hole.

[0100] In some embodiments, pore-forming agents / particles or β-nucleating agents / particles can be used, and the process is still considered a dry process. For example, a particle stretching process can be considered a dry process because the oil or solvent is not extruded with the polymer and is extracted from the extruded polymer to form pores. In a particle stretching process, particles such as silica or calcium carbonate are added to the polymer mixture, and these particles contribute to pore formation. In such methods, for example, a polymer mixture containing particles and polymer is extruded to form a precursor, which is stretched and creates voids around the particles. In some embodiments, the particles can be removed after void formation. Although a particle stretching process may include a stretching step before or after particle removal, a particle stretching process is not considered a dry stretching process because the primary pore-forming mechanism is the use of particles rather than stretching.

[0101] In some preferred embodiments, the structure of dry-process porous membranes may have one or more distinctive features. For example, dry-process membranes may contain more than 10% polypropylene. Wet processes or other processes using solvents are generally incompatible with polypropylene because the solvents degrade the polypropylene. Therefore, wet-process porous membranes typically contain no more than 10% polypropylene, most typically 5% or less. Another distinctive feature of some dry-process porous membranes (particularly those used as battery separators) is their ability to shut off. In some cases, a PP / PE / PP structure can impart a shut-off function. This is unique to dry-process membranes because layers primarily comprising polypropylene (PP) cannot typically be formed in wet processes. Dry processes are particularly well-suited for forming PP / PE / PP shut-off membrane structures.

[0102] In some embodiments, dry-process porous membranes with distinctive features may be present. Figure 3 The thin sheets and fibrils shown. For example, porous membranes can have similar characteristics to... Figure 3 or Figure 4 The structures shown in A and 4B. Figure 4 A and 4B are FESM images showing the contents of PE(A) and PP(B). The slit-like micropores in the microporous membrane. In some embodiments, the pores or micropores of the dry process porous membrane can be circular, elliptical, semi-circular, trapezoidal, etc.

[0103] In some embodiments, a distinguishing feature of dry-process porous membranes is that they are free of or substantially free of pinholes. Pinholes are considered a defect and are generally not a feature intentionally formed in dry-process porous membranes. In some embodiments, dry-process microporous membranes may be free of or substantially free of pinholes larger than 10 nm. In some preferred embodiments, the pores of dry-process porous membranes are tortuous. In some embodiments, a distinguishing feature of dry-process porous membranes is their tortuosity. In some embodiments, the tortuosity of dry-process porous membranes is greater than 1, greater than 1.2, greater than 1.3, greater than 1.4, greater than 1.5, greater than 1.6, greater than 1.7, greater than 1.8, greater than 1.9, or greater than 2.0. In some embodiments, the formula for roughly calculating the tortuosity is formula (2):

[0104] Tortuousness = x / t(2)

[0105] Where "x" represents the length of the opening or pore in the porous membrane, and "t" represents the membrane thickness. The tortuosity of a pinhole is 1 because its length is the same as the membrane thickness. A tortuosity pore has a tortuosity greater than 1, such as... Figure 5 As shown, this is because the length of the pore is greater than the thickness of the membrane.

[0106] In some embodiments, the dry-stretched porous membrane is semi-crystalline. In some embodiments, the dry-stretched porous membrane is semi-crystalline and oriented in a single direction. For example, the membrane may be MD-oriented. Porous thin films formed by wet processes, such as those formed by β-nucleation processes, may be randomly oriented.

[0107] Composite materials or devices

[0108] A composite material or device comprising any coated battery separator or coated porous membrane as described above and one or more electrodes, such as an anode, cathode, or anode and cathode, in indirect or direct contact with it. There are few restrictions on the type of electrode. For example, the electrode can be one suitable for lithium-ion secondary batteries.

[0109] In some embodiments, the composite material or device is at least one battery selected from the following: cylindrical battery, pouch battery, prismatic battery, wound battery, folded battery, wrapped battery, pouch battery, or stacked battery.

[0110] In some implementations, the composite material or device is a secondary battery, such as a lithium-ion battery.

[0111] Lithium-ion batteries according to some embodiments described herein, such as Figure 6 As shown.

[0112] A suitable anode may have an energy capacity greater than or equal to 372 mAh / g, preferably ≥700 mAh / g, and most preferably ≥1000 mAh / g. The anode is composed of lithium metal foil or lithium alloy foil (e.g., lithium-aluminum alloy) or a mixture of lithium metal and / or lithium alloy with materials such as carbon (e.g., coke, graphite), nickel, or copper. The anode is not only made of lithium-containing intercalation compounds or lithium-containing compounding compounds.

[0113] A suitable cathode can be any cathode compatible with the anode and can include intercalating compounds, intercalation compounds, or electrochemically active polymers. Suitable intercalating materials include, for example, MoS2, FeS2, MnO2, TiS2, NbSe3, LiCoO2, LiNiO2, LiMn2O4, and V6O. 13 V₂O₅ and CuCl₂. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline, and polythiophene.

[0114] Any battery separator described above can be incorporated into any vehicle (e.g., an electric vehicle) or device (e.g., a mobile phone or laptop) that is fully or partially powered by a battery.

[0115] Various embodiments of the invention have been described to achieve its various objectives. It should be understood that these embodiments are merely illustrative of the principles of the invention. Many modifications and changes will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0116] In some aspects, capacitors comprising at least one coated separator as described herein are disclosed. In some embodiments, the capacitor may be a supercapacitor.

[0117] In some embodiments, a coated battery separator with a porous membrane as described herein is described, having an additional layer directly on top of the coating. In such embodiments, the coating may contain at least one adhesive, or consist of or substantially consist of at least one adhesive. In some preferred embodiments, the coating may be an aqueous or water-based coating. Such coatings have excellent uniformity and are therefore well-suited for directly coating another coating thereon. For example, the adhesion of the coating may be uniform. The layer directly coated thereon may be at least one of the following: a ceramic coating, a coating or layer of electrode material, a coating or layer of solid electrolyte material, a metal layer or coating, a metal-containing coating or layer, and the like.

[0118] Example

[0119] Example 1 :

[0120] In Example 1, a single-layer separator (porous membrane) made of polypropylene is coated with a coating slurry or mixture comprising PVDF as an adhesive and PE beads as a shut-off agent. In this example, Example 1a uses an adhesive, while Example 1b does not. In Example 1b, PVDF and PE are dispersed in water or a water-based solvent (which may contain up to 50% alcohol or other water-soluble solvents). The coating in 1a is also an aqueous, water-soluble, or water-based coating. The coating is applied to one or both sides (or just one side) of the separator (porous membrane). A schematic diagram of the double-sided coated separator according to Example 1 is shown below. Figure 7 The diaphragm (porous membrane) in Example 1 does not have a shut-off capability.

[0121] Example 2 :

[0122] In Example 2, a single-layer separator made of polypropylene was coated with a coating slurry or mixture comprising PVDF as a wet adhesive, a dry adhesive, and PE beads as a shut-off agent. An adhesive was used in Example 2a, but not in Example 2b. In Example 2b, PVDF as a wet adhesive, the dry adhesive, and the PE beads as a shut-off agent were dispersed in water or an aqueous solvent having up to 50% alcohol or another water-soluble solvent. The coating in 2a was also a water-based or aqueous coating. The coating was applied to one or both sides of the separator. A schematic diagram of the double-sided coated separator according to Example 2 is shown below. Figure 8 The partition in Example 1 does not have the ability to shut off.

[0123] Example 3-202 :

[0124] Examples 3-202 contain the amounts of adhesive and shut-off agent shown in the table below. In each example where “X” appears in the “Adhesive” column, the adhesive is added together with a solvent, which may be water or an aqueous or organic solvent. The amount of adhesive added does not exceed 10% of the total solids in the coating. In some embodiments, no adhesive is added; for example, the adhesive, shut-off agent, and / or inorganic or heat-resistant particles may be dispersed in an organic solvent or in water or an aqueous solvent without an adhesive. The aqueous solvent may contain up to 50% alcohol or another water-soluble solvent. In each example where “X” appears in the “Inorganic or Heat-Resistant Particles” column, inorganic or heat-resistant particles are added. A dash (“-”) indicates that a certain component is not present in the coating of that example. Examples 3-202 are all double-sided coated separators, such as polypropylene monolayer membranes (separators) or porous membranes (separators), each side of which has the same coating. Such double-sided coated separators have also been prepared, one coating being a ceramic coating and the other having a composition similar to that in Examples 3-238. In addition, an exemplary one-sided coated partition was prepared, wherein a coating layer was applied, and the composition of the coating corresponds to the coating composition used in Examples 3-238. Furthermore, embodiments similar to those in Examples 3-238 were prepared, wherein the inorganic or organic heat-resistant particles were nanoparticles (particle sizes less than about 500 nm, less than 450 nm, less than 400 nm, less than about 350 nm, less than about 300 nm, 250 nm, or less than 200 nm) and non-nanoparticles (particle sizes greater than 250 nm, greater than 300 nm, greater than 350 nm, greater than 400 nm, greater than 450 nm, or greater than 500 nm, up to 1,000 nm). Finally, embodiments as in Examples 3-238 were formed, wherein a coating was formed on a ceramic or nanoceramic layer. The coating may be formed continuously or discontinuously on the ceramic or nanoceramic layer. The ceramic or nanoceramic layer described herein is a layer comprising 80%, 85%, or more, 90%, 95%, or 98% or more ceramic or nanoceramic by weight, and optionally a binder or other additives. All embodiments described herein use water as a solvent to form a water-based or aqueous coating solution, which is then coated. Embodiments using solvent-based coating solutions have also been prepared. Aqueous means that the solvent is only water, or water with alcohol or other non-organic water-soluble solvents. For example, an aqueous or water-based coating may contain a solvent that is water and (if present) up to 50% alcohol or a non-organic water-soluble solvent (such as PVA).

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131] Excellent results were found to be obtained using nanoceramics or nanoinorganic materials (nanoalumina in the examples). For example, Figure 12 As shown, the use of nano-alumina in viscous or adhesive coatings reduces self-adhesion by approximately 50%. Figure 12 The nano-alumina used in this process has a particle size of 250 nm. We do not wish to be bound by any particular theory. Figure 13 The proposed mechanism explaining why self-adhesive strength decreases is illustrated. It was also found that nano-ceramics or nano-inorganic materials (nano-alumina in the examples) improve the function of the turn-off coating. For example, during turn-off, the resistance increases by more than 100 Ω, 500 Ω, 1000 Ω, 2000 Ω, 3000 Ω, 4000 Ω, 5000 Ω, 6000 Ω, 7000 Ω, 8000 Ω, 9000 Ω, or 10,000 Ω. These increases in resistance occur at temperatures below 135°C, below 130°C, below 125°C, below 120°C, below 115°C, below 110°C, below 105°C, below 100°C, or below 95°C. This is evident in… Figure 14 The figure compares two implementations: one comprising conventional ceramics with a size of 700 nm, and the other comprising nanoceramics with a size of 250 nm. Without wishing to be bound by any particular theory, it is believed that this improved functional shut-off coating is partly due to the fact that the polymer can flow and block the pores of the separator. For larger inorganic or ceramic or heat-resistant particles, the polymer may have more difficulty flowing and / or blocking the pores of the separator.

[0132] Figure 15 Images of coatings containing PVDF and nanoceramics, and coatings containing PVDF and ceramics, are shown respectively. The nanoceramic-containing coatings can be manufactured to be thinner, at least in part due to the presence of the nanoceramics.

[0133] In some embodiments, aspects, or purposes, a coated separator is disclosed, which comprises a coating on one or both sides of a separator membrane. The coating may contain at least one of an adhesive, a shut-off agent, and a binder. The coating containing these components does not contain any inorganic or organic heat-resistant materials (including ceramic materials), or it contains a small amount of inorganic or organic heat-resistant materials (including ceramic materials). The separator may be a separator that does not itself have shut-off capability. For example, the separator membrane of the separator may be a single-layer separator made of polypropylene. Battery cells, secondary batteries, and capacitors comprising at least one of the coated separators disclosed herein are also disclosed.

[0134] In some embodiments, aspects, or purposes, a coated separator membrane is disclosed, wherein the coating is included on one or both sides of the separator membrane. The coating may contain at least one of an adhesive, a shut-off agent, and a binder. The coating containing these components does not contain any inorganic or organic heat-resistant materials (including ceramic materials), or it contains a small amount of inorganic or organic heat-resistant materials (including ceramic materials). The separator may be a separator that does not itself have shut-off capability. For example, the separator membrane of the separator may be a single-layer separator made of polypropylene. Battery cells, secondary batteries, and capacitors comprising at least one of the coated separators disclosed herein are also disclosed.

[0135] In some embodiments, aspects, or purposes, coated membranes are disclosed, which comprise a coating on one or both sides of a polymer membrane. The coating may comprise at least one of an adhesive, a shut-off agent, and a binder. The coating containing these components may not contain any inorganic or organic heat-resistant materials (including ceramic materials), or it may contain a small amount of inorganic or organic heat-resistant materials (including ceramic materials). The membrane or base membrane may be a membrane that does not inherently possess shut-off capability. For example, the coated membrane may be a single-layer or multi-layer membrane made of polyolefins, polypropylene, blends, or the like. Batteries, battery cells, secondary batteries, capacitors, fabrics, filters, clothing, and / or the like comprising at least one of the coated membranes disclosed herein are also disclosed.

[0136] In some embodiments, aspects, or purposes, multilayer or composite films are disclosed, which include coatings, layers, or treatments on one or both sides of the polymer film. The coatings, layers, or treatments may contain at least one of adhesives, shut-off agents, and binders. Coatings, layers, or treatments containing these components may not contain any inorganic or organic heat-resistant materials (including ceramic materials), or they may contain small amounts of inorganic or organic heat-resistant materials (including ceramic materials).

[0137] The membrane or base membrane may be a membrane that does not have a shut-off capability on its own. For example, the base membrane of a multilayer membrane may be a single-layer or multilayer membrane made of polyolefin, polypropylene, blends, or the like. Batteries, battery cells, secondary batteries, capacitors, fabrics, filters, clothing, and / or the like comprising at least one of the multilayer or composite membranes disclosed herein are also disclosed.

[0138] Various embodiments of the invention have been described to achieve the various objectives of the invention. It should be understood that these embodiments are merely illustrative of the principles of the invention. Many modifications and variations of these embodiments will be apparent to those skilled in the art without departing from the spirit and scope of the invention. For example, nonwoven materials, such as fibers, meshes, nets, or the like, may be added to one or both sides of the coated separator, coated membrane, multilayer or composite membrane, and / or the like.

Claims

1. A coated separator or a coated porous membrane, comprising: Partition and at least one coating; The coating comprises at least one selected from adhesives, shut-off agents, and binders, wherein, The coating contains only a small amount of organic heat-resistant nanoparticles, which is less than 1%, 5%, or 10% of the total solids content in the coating (the separator exhibits a lower shut-off temperature compared to a separator containing standard-sized heat-resistant particles); the coating is water-based or water-based coating comprising a solvent that is water and up to 50% alcohol or non-organic water-soluble solvent.

2. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of an adhesive, preferably, The adhesive comprises, is composed of, or is substantially composed of at least one selected from wet adhesives and dry adhesives; The adhesive comprises, consists of, or is substantially composed of a wet adhesive, preferably comprising, consists of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof; The adhesive comprises, is composed of, or is substantially composed of a dry adhesive, preferably, the dry adhesive polymer comprises, is composed of, or is substantially composed of the following: PVDF-HFP copolymers, or acrylic substances with a glass transition temperature of less than 100°C or between 30°C and 80°C; The adhesive comprises, is composed of, or is substantially composed of a wet adhesive and a dry adhesive. Preferably, the wet adhesive comprises, is composed of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof. Preferably, the dry adhesive polymer comprises, is composed of, or is substantially composed of PVDF-HFP copolymer, or an acrylic substance having a glass transition temperature of less than 100°C. Preferably, the acrylic substance has a glass transition temperature between 30°C and 80°C.

3. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of a shut-off agent, preferably, The shut-off agent comprises, is composed of, or is substantially composed of the following: beads or particles made of a polymer having a melting point of 100°C to 140°C; preferably, the shut-off agent comprises, is composed of, or is substantially composed of PE beads; or, the shut-off agent comprises, is composed of, or is substantially composed of at least one of the following: beads or particles made of a polymer having a melting point of 130°C to 140°C; beads or particles made of a polymer having a melting point of 80°C to 130°C; beads or particles having a melting point of 140°C to 220°C; and combinations thereof.

4. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of adhesives and binders, preferably, The adhesive comprises, is composed of, or is substantially composed of at least one of dry adhesives and wet adhesives; The adhesive comprises, consists of, or is substantially composed of a dry adhesive, preferably, the dry adhesive polymer comprises, consists of, or is substantially composed of: a PVDF-HFP copolymer, or an acrylic substance having a glass transition temperature of less than 100°C or between 30°C and 80°C; The adhesive comprises, is composed of, or is substantially composed of a wet adhesive, preferably comprising, is composed of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof; or The adhesive comprises, is composed of, or is substantially composed of a dry adhesive and a wet adhesive. Preferably, the wet adhesive comprises, is composed of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof. Preferably, the dry adhesive polymer comprises, is composed of, or is substantially composed of PVDF-HFP copolymer, or an acrylic substance having a glass transition temperature of less than 100°C. Preferably, the acrylic substance has a glass transition temperature between 30°C and 80°C.

5. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of a shut-off agent and a binder; preferably, The shut-off agent comprises, is composed of, or is substantially composed of beads or granules made of a polymer having a melting point of 100°C to 140°C. Preferably, the shut-off agent comprises, is composed of, or is substantially composed of PE beads. Alternatively, the shut-off agent comprises, is composed of, or is substantially composed of at least one of the following: beads or granules made of a polymer having a melting point of 130°C to 140°C, beads or granules made of a polymer having a melting point of 80°C to 130°C, beads or granules having a melting point of 140°C to 220°C, and combinations thereof.

6. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of an adhesive and a shut-off agent; preferably, The adhesive comprises, is composed of, or is substantially composed of at least one selected from wet adhesives and dry adhesives. Preferably, the adhesive comprises, is composed of, or is substantially composed of a wet adhesive. Preferably, the wet adhesive comprises, is composed of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof. The adhesive comprises, is composed of, or is substantially composed of a dry adhesive and a wet adhesive, preferably, the wet adhesive comprises, is composed of, or is substantially composed of the following: PVDF, acrylic polymers, or combinations thereof; preferably, the dry adhesion polymer comprises, is composed of, or is substantially composed of: PVDF-HFP copolymers, or acrylic substances having a glass transition temperature of less than 100°C or between 30°C and 80°C; The adhesive comprises, consists of, or is substantially composed of a dry adhesive, preferably, the dry adhesive polymer comprises, consists of, or is substantially composed of: a PVDF-HFP copolymer, or an acrylic substance having a glass transition temperature of less than 100°C or between 30°C and 80°C; The shut-off agent comprises, is composed of, or is substantially composed of beads or granules made of a polymer having a melting point of 100°C to 140°C. Preferably, the shut-off agent comprises, is composed of, or is substantially composed of PE beads. Alternatively, the shut-off agent comprises, is composed of, or is substantially composed of at least one of the following: beads or granules made of a polymer having a melting point of 130°C to 140°C, beads or granules made of a polymer having a melting point of 80°C to 130°C, beads or granules having a melting point of 140°C to 220°C, and combinations thereof.

7. The coated partition or coated porous membrane as described in claim 1, wherein, The coating comprises, is composed of, or is substantially composed of an adhesive, a shut-off agent, and a binder; preferably, The adhesive comprises, is composed of, or is substantially composed of at least one selected from wet adhesives and dry adhesives. Preferably, the adhesive comprises, is composed of, or is substantially composed of a wet adhesive. Preferably, the wet adhesive comprises, is composed of, or is substantially composed of PVDF, an acrylic polymer, or a combination thereof. The adhesive comprises, is composed of, or is substantially composed of a dry adhesive and a wet adhesive, preferably, the wet adhesive comprises, is composed of, or is substantially composed of the following: PVDF, acrylic polymers, or combinations thereof, preferably, the dry adhesion polymer comprises, is composed of, or is substantially composed of: PVDF-HFP copolymers, or acrylic substances having a glass transition temperature of less than 100°C or between 30°C and 80°C; The adhesive comprises, consists of, or is substantially composed of a dry adhesive, preferably, the dry adhesive polymer comprises, consists of, or is substantially composed of: a PVDF-HFP copolymer, or an acrylic substance having a glass transition temperature of less than 100°C or between 30°C and 80°C; The shut-off agent comprises, is composed of, or is substantially composed of beads or granules made of a polymer having a melting point of 100°C to 140°C. Preferably, the shut-off agent comprises, is composed of, or is substantially composed of PE beads. Alternatively, the shut-off agent comprises, is composed of, or is substantially composed of at least one of the following: beads or granules made of a polymer having a melting point of 130°C to 140°C, beads or granules made of a polymer having a melting point of 80°C to 130°C, beads or granules having a melting point of 140°C to 220°C, and combinations thereof.

8. The coated separator or coated porous membrane as described in any one of claims 1 to 7, wherein, The coated partition is a partition with a coating on one side or a partition with a coating on both sides, preferably. The two coated partitions have the same coating, or the two coated partitions have different coatings. Preferably, one of the coatings is a ceramic coating (the partition does not have the shut-off capability at temperatures below 150°C or 140°C when it is not coated; preferably, the partition that does not have the shut-off capability at temperatures below 150°C or 140°C when it is not coated is a dry process partition).

9. The coated partition or coated porous membrane as described in claim 1, wherein, The partition is made of or substantially of polypropylene. Preferably, the partition made of or substantially of polypropylene is a single-layer partition. More preferably, the partition is a dry process partition.

10. The coated partition or coated porous membrane as described in claim 1, wherein, The organic heat-resistant particles have a D50 particle size of 1 to 500 nm; the organic heat-resistant particles have a particle size of 1 to 1,000 nm; the organic heat-resistant particles have a D50 particle size of 1 to 250 nm; or, the organic heat-resistant particles have a D50 particle size of 250 nm to 1,000 nm.

11. A battery cell, secondary battery, or capacitor comprising at least one coated separator as described in claims 1-7, preferably, the battery being selected from at least one of the following: cylindrical battery, pouch battery, prismatic battery, wound battery, folded battery, wrapped battery, pouch battery, and stacked battery.

12. A composite material comprising a coated separator or a coated porous membrane as described in any one of claims 1-7, wherein the coated separator or the coated porous membrane is laminated or adhered to another coated or uncoated separator or coated porous membrane via coating lamination or adhesion.

13. A coated membrane comprising a coating on one or both sides of a polymer membrane, the coating comprising at least one of an adhesive, a shut-off agent, and a binder; the coating comprising these components comprising less than 1% of an organic heat-resistant nanomaterial, including nano-ceramic materials, in the total solids content of the coating; the membrane or base membrane being a membrane that does not itself have shut-off capability, the coated membrane being a single-layer or multi-layer membrane made of polyolefin, polypropylene, or blends thereof; a battery, battery cell, secondary battery, capacitor, fabric, filter, or garment comprising at least one coated membrane; the coating being a water-based or aqueous coating comprising a solvent of water and up to 50% alcohol or a non-organic water-soluble solvent.

14. A multilayer or composite membrane comprising a coating, layer, or treatment on one or both sides of a polymer membrane; the coating, layer, or treatment comprising at least one of an adhesive, a shut-off agent, and a binder; the coating, layer, or treatment containing these components comprising less than 1% of an organic heat-resistant nanomaterial, including nano-ceramic materials, of the total solids content in the coating; the membrane or base membrane being a membrane that does not have shut-off capability on its own, the base membrane of the multilayer membrane being a single-layer or multi-layer membrane made of polyolefin, polypropylene, or a blend; a battery, battery cell, secondary battery, capacitor, fabric, filter, or garment comprising at least one of a multilayer or composite membrane; the coating being a water-based or aqueous coating comprising a solvent of water and up to 50% alcohol or a non-organic water-soluble solvent.

15. A composite material comprising a coated separator or a coated porous membrane as described in claim 1, wherein, An additional coating is applied directly on top of at least one coating, the at least one coating comprising, being, or substantially comprising the following: The coating is selected from at least one of adhesives, shut-off agents, and binders, wherein the coating contains only a small amount of organic heat-resistant nanoparticles, preferably. The coating comprises, is composed of, or is substantially composed of an adhesive. The coating comprises, is composed of, or is substantially composed of adhesives and binders, or The coating comprises, is composed of, or is substantially composed of the following: an adhesive, a binder, and a small amount of organic heat-resistant nano or non-nanoparticles; The coating is water-based or water-based. The small amount of organic heat-resistant nanoparticles is less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% of the total solids content in the coating; and / or Additional coatings are ceramic coatings, polymer coatings, electrode material coatings, solid electrolyte material coatings, metal-containing coatings, and / or metal coatings.

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